4341 4345.output

* GB784748 (A)
Description: GB784748 (A) ? 1957-10-16
Improvements in or relating to hair curlers
Description of GB784748 (A)
PATENT SPECIFICATION
Date of filing Complete Specification: Jan 10, 1956.
Application Date: Oct 20, 1954 No 21058/54.
Complete Specification Published: Oct 16, 1957.
Index at Acceptance:-Class 131, B 4 (A 3: A 4: D).
International Classification:-A 45 d.
COMPLETE SPECIFICATION.
Improvements in or relating to Hair Curlers.
We, GABRIELLE DINGER, of 84 Hallwylstrasse, Zurich 4, Switzerland, and
ALBERT EDWARD LANGLEY, of 33 The Kingsway, Swansea, Glamorgan, both
British Subjects, do hereby declare the invention, for which we pray
that a patent may be granted to us, and the method by which it is to
be performed, to be particularly described in and by the following
statement:-
The present invention concerns improvements in or relating to hair
curlers.
It is an object of the present invention to provide an improved hair
curler suitable for use in permanent waving or curling, 13 setting or
temporary waving or curling of the hair, which, whilst being simple
and cheap to manufacture, is particularly easy and quick to
manipulate.
Thus according to the present invention there is provided a hair
curler comprising a body around which the hair is to be wound, a rod
disposed within and extending longitudinally of the body and being
both slidable and rotatable relative thereto, said rod having rigidly
secured thereto or integral therewith at one end thereof a hair
retaining finger which when the rod is disposed to the fullest extent
within the body overlies the body and is spaced therefrom, the other
end of the rod being suitably shaned so as to prevent complete
withdrawal of the rod from the body and co-operating locking means on

said rod and body which when the rod is disposed within the body to
the fullest extent serve to Drevent relative rotation between the rod
and body.
In order to wind the hair upon the curler the rod is first withdrawn
to its fullest extent so that the hair retaining finger no longer
overlies the body After the hair has been wound on the body, in either
direction of winding, the rod is returned to the fullest extent within
the body in which position it is locked against rotation with respect
to the body and hence the hair retaining finger which now overlies the
hair, prevents it unwinding.
It will be appreciated that it is unnecessary for the hair retaining
finger to grip the hair in order to prevent it unwinding and hence the
hair is not kinked or dented as commonly occurs with existing curlers
e g.
curlers using elastic bands to retain the hair.
The hair retaining finger can if desired be so shaped that its ends
will be closer to the body than the intermediate portion thereof.
Preferably the surface of the body of the curler is roughened to
provide a better grip on the hair when winding it thereon Thus we may
provide roughening projections on the surface such as, for example,
longitudinally extending ribs Alternatively or in addition we may
cover the surface of the body with gauze or other like material If
desired the ends of the body may be knurled or serrated to assist in
manipulation.
It will be understood that the curler may be made in different sizes
in order to produce curls or waves of different shapes and of any
suitable material or materials e g.
wood, metal or plastic e g nylon Furthermore the body of the curler
may be solid with a longitudinal bore therethrough or may be of
composite structure A preferred form of composite structure suitable
for use in the permanent waving or curling of hair comprises a tubular
hair contacting part and an inner tubular member mounted therewithin
which serves to receive the rod The tubular hair contacting part is
preferably perforated and covered with gauze.
Various forms of locking means may be provided to prevent relative
rotation between the rod and body when the rod is 7849748 within the
body to the fullest extent We prefer however to provide a locking
member either mounted on or integral with the rod adjacent either end
thereof and a corresponding shaped recess or aperture suitably
disposed in the body to receive the locking member when the rod is
disposed to the fullest extent within the body Preferably we provide
the locking member and recess or aperture with corresponding
longitudinally extending serrations around the circumference thereof.
We prefer to form the rod and hair retaining finger integrally of a

metal rod or wire suitably bent to the required shape although it will
be understood that the rod and hair retaining finger may be formed
separately and of different materials and then rigidly secured
together in any suitable manner When however the rod and retaining
finger are formed integrally of metal rod or wire we prefer to cover
the hair retaining finger with a sheath of rubber, plastic or other
material.
In order that the invention may be well understood, there will now be
described, two preferred embodiment thereof by way of example only,
with reference to the accompanying drawings, in which:
Fig 1 is a longitudinal section through one preferred form of curler
according to the invention; and Fig 2 is a similar view of another
preferred form of curler.
Referring to Fig 1 of the drawings the curler comprises a body
including a tubular hair contacting part 1 and an inner tubular member
2 which is mounted on the part 1 by means of two collars 3, 4 mounted
one at each end of the member 2 which fit tightly within the part 1
and are secured in position The part 1 is provided with numerous
perforations 5 and is covered by gauze 6 A plug 7 is also partly
within one end of the part 1 and abutting against the collar 4 The
plug 7 is provided with a recess 8 having longitudinally extending
serrations 9 around the circumference thereof which recess
communicates with the member 2 through an aperture 10 in the base
thereof The aperture 10 is of smaller cross-section than the member 2.
A rod 11 and hair retaining finger 12 are formed from a single length
of a wire bent to the required shape Mounted on the rod 11 is a
tapered locking member 12 of complementary shape to the recess 8 and
also having serrations 13 around its circumference which are adapted
to engage the 6 o serrations 9 of the recess 8 to prevent relative
rotation between the rod and body The hair retaining finger 12 is
covered by a rubber sheath 14.
The end 15 of the rod 11 is swaged to a diameter greater than that of
the aperture to prevent the complete withdrawal of the rod 11 from the
body of the curler.
Referring to Fig 2 of the drawings there is shown a curler which
comprises a solid body 16 which tapers from each end to a 70 minimum
cross-section at the centre, having an axial bore 17 extending from
one end of the body and communicating with a recess 18 formed in the
other end of the body through an aperture 19 of reduced 7 5 r diameter
A rod 20 disposed within the bore has an abutment 21 at one end
thereof which will not pass through the aperture 19 and thus prevents
complete withdrawal of the rod from the body A locking member So 22 is
mounted on the rod at its other end and both it and the recess 18 are
provided with longitudinally extending serrations 23, 24 in similar

manner to the locking member 12 and recess 8 of the curler shown in
Fig 85 1 A hair retaining finger 25 forms an extension of the rod 20
and is covered by a rubber sheath 26.
The operation of the curlers of Figs 1 and 2 is identical In order to
wind the 90 hair on the bodies thereof the rod 11 or 20 and hence the
finger 12 or 25 are withdrawn as far as possible to the left as shown
in the drawings but in each case are prevented from complete
withdrawal by the swaged hi end 15 and abutment 21 respectively After
winding the hair on the body in either direction the rod 11 or 20 is
returned to the fullest extent within the body so that the locking
member 12 or 22 engages the recess 100 8 or 18 and the mating
serrations thereof interlock to prevent relative rotation -of the rod
and body so that the finger 12 or 25 which now overlies the hair wound
on the body Prevents the hair from unwinding It 105 will thus be seen
that both the construction and utilisation of these curlers is
particularly simple and effective.
Although two preferred embodiments of the invention have been
described in detail 110 by way of example only, it will be understood
that alterations and modifications thereto may be made without
departing from the scope of the invention as defined in the appended
claims 115
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* GB784749 (A)
Description: GB784749 (A) ? 1957-10-16
Improvements relating to lamp standards and the like

Inventor:-THOMAS CROPPER RYLEY SHEPHERD.
i Date of fllingj Complete Specification: Nov 29, 1955.
Application Date: Dec 13, 1954 No 36038/54.
Index at Acceptance Class 45, F.
International Classification:-E 02 d.
Improvements relating to Lamp Standards and the like.
We, THE EDISON Sw AN ELECTRIC COMP At AY LI Mn TED, a British Company,
having its registered office at 155 Charing Cross Road, London, W C 2,
do hereby declare the invention, for which we pray that a patent may
be granted to us, and the method by which it is to be performed, to be
particularly described in and by the following statement:This
invention relates to lamp posts or standards and to other posts or
standards such as are used for example in mounting traffic lights or
signs, and for supporting overhead power supply lines for trolley
buses.
Hitherto it has been common practice for such lamp, or other posts or
standards to be erected in one piece with a length thereof buried
below ground and supported usually in concrete poured into a hole in
the ground at the time the post or standard was erected.
The present invention provides an improved construction which
facilitates erection, reduces transport costs and affords other
material advantages as will hereinafter appear.
According to the present invention a lamp or other post or standard
comprises a precast or preformed plinth and a hollow column, wherein
the plinth is in the form of a substantially solid block wholly or
substantially buried below ground level or adapted to be so buried,
and includes an upwardly extending spigot co-operating with the lower
end of the hollow column to provide support of said column in
directions longitudinally and transversely thereof, said block being
provided with a through passage for an electrical cable between an
opening located below ground level and an opening in the upper face of
said spigot within the bore of the hollow column Conveniently, the
hollow column may be constructed of an aluminium or other _gkigtalloy
The cables or leads lPr l will enter the plinth at a level which will
be below ground and pass directly through it into the interior of the
column for connection 45 to the lamp or sign or wiring system at the
upper end of the column.
In addition to the support of the column afforded by engagement of the
spigot in the open end of the column, it is also contem 50 plated to
seat the end of the column in a groove in the face of the plinth
extending round the spigot This groove may advantageously be tapered
in cross-section With this arrangement, it is envisaged that, after 55

the column is mounted in position on the plinth, the channel will be
filled with sealing material, conveniently a thermo-setting material
such as bitumen whereby to prevent corrosion and erosion at the bottom
of the 60 column.
One embodiment of the invention will now be described by way of
example with reference to the accompanying drawing, the single Figure
of which is a sectional side view 65 of the lower part of the lamp
post or lamp standard.
The post or standard comprises a precast concrete plinth 1 having a
generally rectangular cross-section and a hollow aluminium alloy 70
column 2 The plinth is provided at the top thereof with a spigot 3
preferably tapered inwardly in the direction of the column A channel 4
of tapered crosssection extends peripherally round the lower 75 end of
the spigot Said plinth is cast with a substantially L-shaped
electrical conduit extending through it from the end face of said
spigot to emerge at a side of said plinth.
In erecting the lamp post or standard the SO plinth is submerged in
the ground with the spigot projecting vertically upwardly above
pavement level ( 6) Thereafter an enlarged end 7 of the aluminium
alloy column is 784,749 784,749 placed over the spigot so as to seat
in the channel 4 The channel is filled with bitumen 8 whereby to
provide a waterproof seal between the column and the plinth at or
substantially at pavement level While the bitumen is still fluid the
column is finally set in the desired vertical position by means of
tapered wedges 9 engaging between the tapered spigot and the adjacent
1 fs inner surface 10 of the enlarged end of the column The wedges
which may be inserted through a door or panel (not shown) in the side
of the column enable small adjustments of the vertical position of the
column to be effected.
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* GB784750 (A)
Description: GB784750 (A) ? 1957-10-16

Process for the treatment of boiler feed water
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
Inventor: JOHN ALAN GRAY 784,75 O Date of filing Complete
Specification (under Section 3 ( 3) of the Patents
Act, 1949): Dec 2, 1955.
Application Date: Dec 20, 1954.
Application Date: Oct 11, 1955.
No 36832/54.
No 28935/55.
' Complete Specification Published: Oct 16, 1957.
Index at acceptance:-Classes 46, B 11 B, C; and 123 ( 1), D 2 B.
International Classification:-C 02 b F 061.
COMPLETE SPECIFICATION
Process for the Treatment of Boiler Feed Water ERRATA SPECIFICATION No
784,750
Page 1, line 92, for " 20 " read " 200 " Page 2, line 108, the formula
"( 3 Mg O 2 T Si O 2 H,O)" should read "( 3 Mg O 2 Si O 2 H,O) THE
PATENT OFFICE, 12th December, 1957.
z ERRATA SPECIFICATION NO 784, 750
Page 2, line 92, for " 20 " read " 200,".
3 Page 2, line 108, the formula ( 3 g O T 22 H) sh O Uld read "( 3 Mgo
28102 2)H 20) THE PATENT OFFICE, 31st Decemnber, 19 f 7 intervalo l be
done is generally governed by the maxiniurn content of dissolved and
suspended solids the boiler water can carry without foaming Sometimes
the sludges are less free-flowing and resist removal by blowing-down
but can still DB 01820/2 ( 9)/3624 150 12/57 R magnesium content of te
IC wa UL Lo advantageous to raise it by additions of suit 90 able
magnesium compounds Starch and tannins are known to modify the types
of prePATENT SPECIFICATION
Inventor: JOHN ALAN GRAY 7849750 Date of filing Complete Specification

(under Section 3 ( 3) of the Patents
II S 17 9 Act, 1949): Dec 2, 1955.
Application Date: Dec20, 1954 No 36832/54.
Application Date: Oct11, 1955 No 28935/55.
w W / Complete Specification Published: Oct16, 1957.
Index at acceptance:-Classes 46, Bli B, C; and 123 ( 1), D 2 B.
International Classification:-CO 2 b F 061.
Process for the Treatment of Boiler Feed Water We, IMPERIAL CHEMICAL
INDUSTRIES LIMITED, of Imperial Chemical House, Millbank, London, S W
1, a British Company, do hereby declare the invention, for which we
pray that a patent may be granted to us, and the method by which it is
to be performed, to be particularly described in and by the following
statement: -
This invention relates to a process for the treatment of water for
steam generation in boilers, and more particularly to those boilers
and waters with which operating pressures and other conditions are
such that calcium carbonate is precipitated inside the boiler.
When boiler feed water is softened and conditioned before it enters
the boiler system any compounds precipitated as a result of the
treatment may be removed by settling or filtering and consequently
find their way into the boiler only in such small amounts as cause
little trouble during steam generation It is different when the water
treatment is applied to water already in the boiler or in a feed
vessel not arranged for settling for then nearly all precipitation of
compounds takes place in the boiler and causes sludges to be formed.
Such sludges consist to a large extent of calcium carbonate since
waters used for steam generation often contain in the raw state more
calcium compounds than any others, for example magnesium compounds;
some contain silicon compounds and a few contain aluminium compounds,
but the amounts of the former are usually small in relation to the
calcium compounds, and the amounts of aluminium compounds usually do
not exceed one or two parts per million expressed as A 120, Sometimes
these sludges are freeflowing and may be prevented from accumulating
by blowing-down the boiler at intervals The frequency with which this
has to be done is generally governed by the maximum content of
dissolved and suspended solids the boiler water can carry without
foaming Sometimes the sludges are less free-flowing and resist removal
b lwing-down but can still be removed from the empty boiler by means
of a jet of water Sometimes they form deposits that cement together
insoluble particles formed elsewhere and then they are too compacted
to be removed except by mechanical means such as chipping or scraping
It follows that sludges that are not free-flowing enough to be removed
by blowingdown are a cause of increased cleaning and maintenance costs

and can, if not removed, lead in the end to failure of the boiler
through overheating of metal heat-transfer surfaces and through other
causes.
It is an object of this -invention to provide a process for treating
boiler feed water whereby all precipitated solids in the boiler are in
the form of a sludge that is free-flowing and non-adherent and
consequently able to be removed by blowing-down.
A further object of the invention is to provide a process for treating
boiler feed water that in addition to rendering boiler sludges
free-flowing will prevent or reduce to negligible amount the formation
of calcium carbonate scale on surfaces inside the boiler.
It is known that to be free-flowing and easily removed by blowing-down
a sludge should in general be highly flocculent It then has a high
water content, of the order of 80 % calculated on the settled sludge,
is readily maintained in suspension by circulating water and if
allowed to settle does not compact to a dense deposit but is taken up
into suspension again when circulation is resumed, or flows towards a
blow-down outlet.
Various chemicals are commonly used to improve the mobility of
sludges, for example tannins, starch and sodium aluminate The latter
is sometimes useful in combination with starch or tannin when the
magnesium hardness of the feed water is more than 15 % of the total
hardness; in some such cases where the magnesium content of the water
is low it is advantageous to raise it by additions of suitable
magnesium compounds Starch and tannins are known to modify the types
of pre_ <<<CHAR-SET=99>>> ipitates produced in the boiler and it has
usually been considered that the presence of a flocculent magnesium
aluminate gel in a sludge was the essential factor in making the
sludge free-flowing, though as far as is known the use of sodium
aluminate, starch, tannin and other materials has been on an empirical
basis and not related in any recognisably regular way to feed water
composition.
We have now discovered that contrary to the commonly held belief that
behaviour of a sludge is mainly dependent on the amount of aluminium
compounds present in the environment it is in fact the concentration
of magnesium compounds that is decisive We have also discovered how to
relate numerically the concentration of magnesium compounds required
to make a sludge free-flowing to the concentrations of other
substances present in a feed water.
Accordingly the present invention provides in the known alkaline
treatment processes as hereinafter defined given to boiler feed waters
and boiler waters, a method for rendering the resulting boiler sludges
free-flowing characterised in that a readily-soluble magnesium
compound is added to the boiler feed water in such amount that the

value of the expression Mg O 2 l Si O 2 Ca O 3 3 in which Ga O, Mg O
and Si O 2 are respectively the equivalents in moles of the calcium,
magnesium and silicon compounds in the boiler feed water, is greater
than 4 and preferably greater than 7.
It should be emphasised that any adjustment of the concentration of
magnesium compounds in a feed water in accordance with the above
expression of our invention is supplementary to, and in no way
replaces, the known customary alkaline treatment given to waters to
condition them for steam generation, and it should be accordingly
understood that the operation of our invention is dependent on the
maintenance in the water of that degree of alkalinity which normally
follows from such alkaline treatment, for example the addition of
sodium carbonate or caustic soda, together, if desired, with other
substances such as antifoam agents, deoxygenating agents This degree
of alkalinity is usually equivalent to several hundred parts per
million of sodium carbonate In this known alkaline treatment it is
customary to inject a solution of the alkali and any other desired
additives into the boiler, or into the feed water before it enters the
boiler, or to allow the feed water, or part of it, before it enters
the boiler to flow through a vessel containing the alkali and any
other desired additives in solid soluble form.
Common to all these alternatives is the fact that the
water-conditioning reactions occur inside the boiler and not in some
external settling vessel.
The process of our invention is applicable to all feed waters
generally used for industrial 65 purposes Such waters may conveniently
be classified as (i) waters of lakes and streams in moorland country,
(ii) waters of lakes, reservoirs, rivers and canals in lowland
country, (iii) water from wells, springs and 70 lower measures of coal
mines In the first of these classes the water is soft; the combined
concentration of dissolved calcium and magnesium compounds is in
general in the range of about 0-50 parts per million (ex 75 pressed as
Ca CO,), and the concentration of silicon compounds is from 0-10 parts
per million (expressed as Si O 2) Waters of the second and third
classes stretch from those moderately soft to those that are very
hard; 80 the concentrations of dissolved calcium and magnesium
compounds falling roughly within the range 50-300 and 10-75 parts per
million (expressed as Ca C Ou) respectively, the concentration of
silicon compounds being 85 about 10-15 parts per million (expressed as
Si O 2) as a rule.
As discussed above, most boiler sludges consist of calcium carbonate
This comes about because the treatment applied in the large 90 numbers
of boilers operating at pressures less than about 20 lb /sq inch or at
any pressure at which calcium carbonate can be precipitated usually

takes the form of additions of sodium carbonate or caustic soda, along
with various 95 other auxiliary materials such as sodium aluminate,
phosphates, tannins, starch The sodium carbonate or caustic soda
reacts with the soluble calcium compounds responsible for most of the
hardness of the feed water and 100 precipitates calcium carbonate as a
result.
We have found from an examination of numerous boiler sludges that the
least mobile are composed almost entirely of calcium carbonate in the
form of calcite Free-flowing 105 sludges we find on the other hand to
contain proportions of one or more of serpentine ( 3 Mg O 2 T Si O 2 2
H 0), kaolinite (AL-0, 2 Si O 2 21120) and magnesium hydroxide In
general non 110 mobile sludges are not flocculent whereas free-flowing
sludges are highly so, and in fact the most desirable property to
induce in a boiler sludge is high degree of flocculation, which comes
about when a magnesia or 115 magnesia/alumina gel is present in it
though the dominant factor in the latter is the part played by the
magnesia Another desirable objective is for the crystal shape of the
compounds constituting the sludge to be that of 120 long needles,
since these do not readily compact once they have settled.
We have discovered further that in all cases where the amount of
magnesium compounds in a feed water has been adjusted to comply with
125 the expression of our invention, the formation of calcium
carbonate scale on surfaces inside the boiler is prevented or at least
reduced to a 784,750 aluminium compounds may be ignored calculating
the value of the expression Mg O 2 negligible amount It is not clear
how this comes about since absence of scale makes it impossible to
discover by analysis what part magnesium compounds play It is known
that some magnesium compounds can remove silica from water, and in so
far as a calcium carbonate scale may have its tenacity increased by
the presence of silicon compounds, removal of silica would weaken such
scale but could not account for its not being formed at all It may be
that many examples of socalled calcium carbonate scale are in fact
adherent deposits of compacted calcium carbonate sludge, and if that
were so one would not expect to find evidence of scale whenever sludge
was free-flowing.
In calculating the value of the expression Mg O 2 l Si O 2 l Ca O 3 3
one requires analytical data for the calcium, magnesium and silicon
compounds present in the raw water Thus the accuracy of the value
depends on the accuracy with which these data are determined and on
the experimental errors involved In fixing a minimum value for the
expression one ought therefore to take these things into account if
the invention is to be practised successfully Basing our calculations
on analytical data of the highest accuracy we have found that if the
value is less than 4 the chance of a sludge being free-flowing is so

small as to be negligible; if between 4 and 7 some sludges are likely
to be free-flowing, and if greater than 7 the probability of a sludge
not being free-flowing is virtually zero Likewise with regard to the
formation of calcium carbonate scale: below a value of 4 scaling
occurs readily, between 4 and 7 it is diminished in degree and above 7
it is substantially prevented altogether To allow for large errors in
analysis of the water and for inaccurate control of the process, one
might recommend the minimum to be set at a higher value, for example
10, since in general the higher the value the more free-flowing the
sludge, though beyond values of about 25 no significant improvement is
obtained But to set the minimum as high as 10 merely for such reasons
would be to deny the force of the observations that it can be safely
as low as 7 always, and in some cases as low as 4.
As discussed above, we now have found that it is not necessary, as far
as sludge control and calcium carbonate scale prevention are
concerned, to add aluminium compounds to the water but it is necessary
to consider the circumstances that arise when the water already
contains aluminium compounds.
There are examples of feed waters that contain small amounts of
alumina, and it may sometimes be desirable to add aluminium compounds,
for example sodium aluminate, to the water for other reasons We have
found that in such aluminium-containing waters the in l a Si O 2 l Ca
O 3 3 and provided the value is greater than 4 and preferably greater
than 7 sludge formed in boilers fed with the waters will be
free-flowing and calcium carbonate scale formation 70 negligible It
has been stated that adjustment of the magnesium content of a water is
supplementary to and in no way replaces the normal alkaline
conditioning treatment given to boiler waters by known methods In the
same way it 75 is supplementary to other treatments given to some
waters from time to time for other purposes, for example the addition
of antifoaming agents, or de-oxygenating agents including tannins
Among antifoaming agents 80 compatible with the process of the
invention are certain polyoxyalkylene glycols having a molecular
weight greater than 1000, for example polyoxyethylene glycols and
polyoxypropylene glycols; certain mono and 85 diethers of
polyoxyalkylene glycols having molecular weights greater than 500, for
example the mono-butyl ether of a polyoxypropylene glycol and the
dicetyl ether of polyoxyethylene glycol; certain polyacyl poly 90
amines, for example di-palmityl ethylene diamine Among de-oxygenating
agents sodium sulphite and sodium nitrite, tannins, hydrazine may be
mentioned.
A convenient way of adjusting the concen 95 tration of magnesium
compounds is by adding magnesium sulphate to the feed water Preferably
a solution of magnesium sulphate is continuously fed into a boiler

feed water vessel, which may be supplied with entirely 100 raw water
or with a mixture of raw water and boiler condensate, whilst the
alkalies required for the normal alkaline treatment may be introduced
directly into the boiler or into the feed water before it enters the
boiler, so that in 105 either case precipitation of sludge occurs in
the boiler The solution of magnesium sulphate may be supplied as such
from a stock tank previously prepared, or on the other hand briquettes
of, -or containing, magnesium 110 sulphate may be packed into a
by-pass feeder and dissolved gradually as feed water passes over them
If desired other substances such for example as antifoaming agents and
de-oxygenating agents may be incorporated with the 115 magnesium
sulphate in a briquette Other magnesium compounds may be used, for
example the nitrate, carbonate, chloride.
Since under all ordinary working conditions within the scope of this
invention substantially 120 all the lime, magnesia, silica and alumina
in a feed water appear in the boiler sludge, it is of interest to
examine in the light of the invention the compositions of some actual
boiler sludges.
It has been possible to analyse the sludges from 125 26 working
boilers of which 7 were free-flow784,750 ing and 19 non-mobile For the
free-flowing 7 9, 6 9, 5 6 and 4 1 For the non-mobile sludges the
values of the expression sludges the values were 5 0, 4 7, 4 3, 4 2, 4
1, Mg O 2 3 3, 1 3, 0 8, 0 5, 0 4, 0 4, 0 0, -0 8, -0 8, -0 4, l Si O
2 l -1 1, -1 7, -1 8 and -6 1Actual analytical data Ca O 3 3 for the
highest and lowest values in each group worked out to be respectively
18 9, 15 1, 13 3, are given in the table below 1 % moles per 100 moles
Ca O Value Ca O Mg O A 1203 P 205 Si O 2 Mg O Si O 2 A 1203
free-flowing 33 60 16 86 nil 18 40 2 36 69 8 6 6 nil 18 9 free-flowing
47 75 4 94 2 89 nil 0 58 14 4 1 1 3 3 4 1 non-mobile 49 56 5 63 0 06 1
42 0 16 15 8 0 3 0 1 5 0 non-mobile 44 33 5 05 0 86 2 00 8 10 15 8 17
1 1 1 -6 1 I In the following examples, which further illustrate but
do not restrict the invention, the expression Mg O 2 l Si O 2 l Ga O 3
3 is for convenience referred to as "the formula index " EXAMPLE 1.
An 'Economic' boiler working at a pressure of 100-120 p s i and
evaporating 60009000 gallons of water per 24 hours was being fed with
a water which had in the raw state high calcium and low magnesium
hardnesses respectively of 232 and 14 parts per million expressed as
Ca CO, and a medium silica content of 7 parts per million, and which
was being treated with sodium carbonate and an anionic surface-active
agent with dispersing properties This boiler had a long history of
intractable non-mobile sludge and had always showed a considerable
degree of scale formation The formula index for the feed water worked
out to be approximately minus 1.
The existing treatment was terminated and replaced by additions of

caustic soda sufficient to maintain the total alkalinity equivalent to
500 parts per million of sodium carbonate In addition magnesium
sulphate solution was continuously fed in such amount as to raise the
magnesium content of the feed to approximately 90 parts per million
(as Ca CO,) With these proportions the formula index was just below 10
After four months under these conditions the boiler was examined and
found to be virtually free from sludge, what there was being
free-flowing Test plates in the boiler were completely free of scale
and a test area had deposit estimated at less than 0 001 inch in
thickness.
EXAMPLE 2.
This is an example of a feed water of high calcium hardness and low
magnesium hardness, namely respectively 288 and 16 parts per million
expressed as Ca CO,, and of high silica content namely 21 parts per
million This water had been treated with various alkaline tannin
mixtures and fed to a locomotive-type boiler working at 150 p s i
Non-mobile sludge formation had been considerable, and it had been
necessary to wash out the boiler every six weeks The formula index was
approximately minus 5 5 The existing treatment was replaced by one
based on caustic soda as in Example 1, and magnesium sulphate was
added to bring the magnesium content to approximately 135 parts per
million (as Ca COQ) The corresponding formula index was now
approximately 8 3.
After three months working under the new conditions the boiler was
completely clean.
This boiler was one of a pair of the same kind working side by side
The second one was operated concurrently in the same way and with the
same treatment as the first except for an addition to the feed of
sodium aluminate equivalent to 5 parts per million of AI 20,.
Substantially equivalent results were obtained, the boiler after three
months being completely clean.
EXAMPLE 3.
This is an example of a feed water of medium to high calcium hardness
and fairly high magnesium hardness namely respectively and 50 parts
per million expressed as Ga CO,, and of medium silica content namely
parts per million The formula index of this was approximately 3 7 The
treatment had been based on sodium aluminate, sodium carbonate and
starch, and sodium sulphite.
The boiler was an 'Economic' working at 80-100 p s i evaporating
6000-9000 gallons per 24 hours with a raw water make-up of to 60 % It
contained a considerable amount of scale and had a long record of
non-mobile sludge The existing treatment was replaced by one based on
sodium carbonate equivalent 784,750 and in addition two cleaned areas
on the smoke tubes and two scaling plates which had been installed in

the boiler were found to be free from deposit Such satisfactory
conditions had never formerly been achieved with the phosphate
treatment, and the example illustrates the usefulness of the process
of the invention in replacing phosphate treatment, which is not always
effective.
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* 5.8.23.4; 93p
* GB784751 (A)
Description: GB784751 (A) ? 1957-10-16
Check circuit for electronic ciphering arrangement for teleprinter signals
A high quality text as facsimile in your desired language may be available
amongst the following family members:
DE1017646 (B) FR1124016 (A) DE1018452 (B) FR68606 (E)
FR69910 (E) FR70167 (E) FR76696 (E)
DE1017646 (B) FR1124016 (A) DE1018452 (B) FR68606 (E)
FR69910 (E) FR70167 (E) FR76696 (E) less
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.

m- Date of Application end filing Complete Specification: Jan18, 1955.
Application made in Norway on Jan 18, 1954.
Patent of Addition to No 784,530, dated Jan 18, 1955).
Index at acceptance: -Class 40 ( 3), H( 15 K:ISX:31).
International Classification:-HO 41.
Check Circuit for Electronic Ciphering Arrangement for Teleprinter
Signals We, STANDARD TELEPHONES AND CABLES LIMITED, a British Company,
of Connaught House, 63, Aldwych, London, W C 2, England, do hereby
declare the invention, for which we pray that a patent may be granted
to us, and the method by which it is to be performed, to be
particularly described in and by the following statement:-
The present invention relates to an electronic arrangement for
ciphering and deciphering teleprinter signals.
The invention constitutes an improvement in or modification of, the
invention described and claimed in the specification of co-pending
Application No 1557/55 (Serial No.
784,530) In what follows, the Specification just mentioned will for
convenience be referred to as the " parent specification "
The object of the present invention is to provide testing means for
indicating faults due to missing pulses in the operation of the
arrangement of the parent specification.
This object is achieved according to the invention by providing an
electronic arrangement for ciphering or deciphering teleprinter
character signals according to claim 1 of the parent specification
further comprising testing means controlled by the input or output
character signals, and by pulses produced in the said arrangement, for
indicating the absence of pulses whose presence is necessary for the
proper operation of the arrangement.
By a "teleprinter character signal" is meant a ggroup of marking or
spacing code elements comprisinff a start element followed by a train
of code elements (usually five) and terminated by a stop element The
start element is generally a spacing element and the stop element a
marking element.
The invention will be described with reference to the accompanying
drawings, in which:Fig 1 shows a block schematic circuit diagram of
one form of the invention This figure is substantially the same as Fig
3 of the parets ecification with the addition of lPri As the testing
arrangements according to the present invention; Fig 2 shows graphical
diagrams of pulses used in explaining the invention; 50 Fig 3 shows a
simplified form of Fig 1 providing less complete testing facilities;
Figs 4 to 7 show circuit details of the ciphering and deciphering
arrangement and are the same as Figs 4 to 7 of the parent 55

specification;
Fig 8 shows how Figs 4 to 7 should be put together to form a complete
circuit; Fig 9 shows waveform diagrams used in explaining the
operation of the ciphering 60 arrangement; and Fig 10 shows details of
the testing circuit according to the present invention It should be
placed to the right-hand side of Fig 7, the terminals A, B, C, D and E
of Fig 7 65 being respectively connected to the correspondingly
designated terminals of Fig 10.
Referring to Fig 1, input teleprinter character signals are supplied
over conductor 11 to an electronic distributor circuit com 70 prising
the blocks 1 to 4, and to an electronic gate circuit 6 in which the
signals are combined by " false addition " (as understood from the
parent specification) with corresponding key character signals
supplied over 75 conductor 16 The electronic distributor comprises a
start-stop circuit 1 which controls a source 2 of timing pulses over a
conductor 12 The timing pulses are supplied over conductor 13 to
control a scale-of-two counting 80 circuit 3 which is connected over a
group of conductors 14 to a rectifier matrix 4 which supplies reading
pulses in succession respectively over a group of conductors,
indicated at 15, to a tape transmitter 5 or like device 85 which is
fed with tape (not shown) on which are punched in known manner
successive key character signals corresponding to, but generally
different from successive teleprinter character signals supplied over
conductor 11 90 The tape is stepped forward after the transmission of
each character signal by a readin g pulse supplied over one of the
conductors 15.
The key character signals are produced by appropriate selection of the
reading pulses by the tape transmitter 5 and are supplied over
conductor 16 The ciphered or deciphered character signals are supplied
from the combining gate circuit 6 over conductors 17 to a
two-condition multivibrator device 7 which acts to amplify and shape
the output character signals which are delivered to conductor 71.
If desired, timing pulse X from the source 2 may be supplied over
conductor 26 to the gate circuit 6 for regenerating the combined
character signals The conductor 26, and the multivibrator 7 are,
however not essential and can be omitted.
The testing arrangements according to the present invention comprise a
gate circuit 8 (called the "first test gate ") having three control
conductors 18, 28 and 48 connected to the tape transmitter 5, and a
fourth control conductor 38 connected to the rectifier matrix 4 The
gate circuit 8 has an output conductor 19 connected to a second gate
circuit 9 (cabled the "second test gate ") which controls an alarm
relay (not shown) over conductor 91.
The gate 8 is such that a positive potential appears on conductor 19

so long as there is a positive pulse or potential on at least one of
the four control conductors.
The output character signal from the multivibrator 7 (or from the gate
circuit 6 if the multivibrator is omitted) is also supplied to the
gate circuit 9 which is of the kind which will release the alarm relay
(not shown) to given an alarm if positive potential is missing from
both input conductors simultaneously As will be made clear later if a
positive pulse which should appear on one of the input conductors 18,
28, 38 and 48 during the period of a character signal is missing at a
time when the output character signal has a spacing element (which
will be & nopotential condition), then the gate 9 fill have no
potential applied to either input conductor, and the alarm will be
given.
As will be explained later, the conductor 26 is only required when
regeneration is used in the gate circuit 6.
The operation of Fig 1 will be more clearly understood by reference to
Fig 2.
Assuming a five-element teleprinter code, and a telegraph speed of 50
bauds, graph a represents a positive pulse of duration 20 milliseconds
which corresponds to the startelement of a character signal, and which
should be produced by the rectifier matrix 4 and should appear on
conductor 38, Fig 1.
Graphs b to f represent similar positive pulses corresponding
respectively to the five code elements, and which should appear on
five corresponding ones of the conductors 15, and which are
distributed by the tape transmitter 5 to conductor 18 or conductor 48,
according to the key character signal Graph g indicates a positive
pulse produced by combining the pulses of graphs a to f Assuming that
regeneration is not used, and that the 70 conductor 26 is omitted, the
pulses of graphs a to f will be applied to the gate circuit 8 over
conductors 38, 18 and 48 so that on the assumption that no pulses are
missing, a positive potential will be applied to the gate 75 circuit 8
for the whole period of the pulse shown in graph g, and a positive
output will be supplied over conductor 19 to the gate 9.
Graph I, Fig 2 shows an example of an output signal applied over
conductor 71 to gate 80 9 In this example, spacing elements
(nopotential condition) occur during the start period, and during code
element periods 2 and 4 If one of the pulses of graphs a, c or e
(which normally occur at the times of these 85 spacing elements)
should be missing, the gate 9 will have no potential supplied over
either input conductor 19 or 71, a Rtd the alarm will be given It will
be clear that in a succession of g very few output signals, a space
element 9 Q will occur sometime in every one of the periods start, 1,
2, 3, 4, 5 and an alarm will be given in response to the loss of any

of the pulses shown in graphs a to f.
When regeneration is used, a slightly dif 95 ferent procedure is
adopted In this case the regenerated character signal is delayed by
half an element period ( 10 milliseconds) The additional conductor 26
(Fig 1) is now used.
Referring to Fig 2, graph j shows a pulse of 100 milliseconds duration
and corresponding to the second half of the pulse, graph a which is
supplied over conductor 38 (Fig 1) in circumstances which will be
explained later on Graph k shows a pulse of 20 milliseconds 105
duration which follows the graph f pulse and is used to step forward
the tape (not shown) in the transmitter 5 This pulse is supplied over
one of the conductors 15 and over conductor 28 to the gate circuit 8
Graph m rep 110 resents a pulse corresponding to the combination of
the pulses shown in graphs j, b to f and k Graph N shows an example of
a regenerated output character signal which is half an element period
later than the signal 115 shown in graph h.
Under normal conditions, positive potential is supplied to the gate 8
over one of the conductors 18, 28, 38 and 48 for the whole period of
the pulse shown in graph m As be 120 fore, if one of the pulses of
graph j, b to f or k is missing, it will be detected by a space
element of one of the output signals which overlaps by 10 milliseconds
the normal period of the missing pulse, and so the relay con 125
trolled by the gate 9 will give the alarm in the manner previously
described.
-Fig 3 shows a simpler arrangement in which only the conductors 18 and
48 are used This only checks the pulses shown in 130 784,751 is
shunted by the anode-cathode circuit of a stop valve V 9 which is
normally conducting, so that the oscillation circuit is heavily loaded
and no oscillations can be generated The control grid of the valve V 9
is connected to 70 the anode of the valve V 15 through a reversing
valve V 8, so that V 15 being normally conducting, V 8 will be blocked
and V 9 conducting As already explained, on receipt of the start
element, V 15 becomes blocked, and so 75 V 9 also becomes blocked and
oscillations of the valve V 10 A can start If the stopping current
through the valve V 9 is suitably chosen, it can be arranged so that
the oscillations start without transients, and so that the first 80
half-cycle of oscillation at the grid of the valve V 10 A is positive
whereby the first timing pulse supplied to conductor 13 occupies the
first half of the start element period and is negative Graphs A and B,
Fig 85 9 show the oscillations and timing pulses, respectively When
the multivibrator V 14, V 15 returns to the stable condition, valve V
9 is unblocked again and no more timing pulses are generated 90 In Fig
6 are shown three double valves Vii, V 12 and V 13 each of which is
arranged as a conventional binary counting stage.

These valves comprise the counting circuits 3 of Fig 1 Eight groups of
rectifiers SR 7 to 95 SR 14 comprise the matrix 4 During the initial
stop period before the receipt of a character signal, the right-hand
section of each of the double valves Vii, V 12 and V 13 is conducting
and the left-hand section is 100 blocked The anode of a section which
is conducting is at a potential near zero, and that of a section which
is blocked is at a relatively high positive potential The conductor 13
from the valve V 1 OB (Fig 4) is connected 105 symmetrically to both
the control grids of the valve V 11; the right-hand anode of the valve
Vii is connected to both the control grids of the valve V 12, and the
right hand anode of the valve V 12 is connected to both 110 the
control grids of the valve V 13 Thus any counting stage receiving a
negative pulse from the preceding stage or from conductor 13 is
switched over to the opposite condition in the conventional way The
arrangement 115 thus counts up to 8 timing pulses.
The arrangement operates in the following well known manner.
The first negative timing pulse which arrives over conductor 13 at the
end of a stop 120 period cuts off the conducting right-hand section of
the valve V 11 and switches the valve over to the opposite condition
with the right-hand section blocked and the left-hand section
conducting The negative timing pulse 125 has no effect on the
left-hand section because it is initially already blocked A positive
pulse is thereupon supplied from the right-hand anode of the valve Vil
to the control grids of the valve V 12, but the grids are so biased
130 graphs b to f, corresponding to the code elements 1 to 5, under
the control of the input character signal which is applied direct to
the gate 9 The combining gate circuit 6 and the multivibrator 7 of Fig
1 are not shown in Fig 3 The gate 9 operates in the same way as in Fig
1, except that it is controlled by the input character signal instead
of by the output ciphered character signal.
Reference will now be made to the detailed circuit diagrams, Figs 4 to
7, put together as shown in Fig 8 In Fig 4, the start-stop circuit 1
of Fig 1 comprises the valves V 14, V 15, V 8 and V 9, and the timing
pulse source 2 comprises the valves V 1 OA and V 1 OB The incoming
teleprinter character signals are supplied to the control grid of a
valve Vi A, and it will be assumed that the potential applied to this
grid is about zero, or slightly positive, during marking periods, and
negative during spacing periods The conductor 11 connected to the
anode of the valve Vi A will thus be a a potential near zero for
mnarking periods (since the valve Vi A is then conducting) and at a
positive potential during spacing periods, (since the valve Vi A is
then blocked).
The two valves V 14 and V 15 are connected to form a single-stable
multivibrator, and thzt valve V 15 is conducting and the valve V 14 is

blocked in the stable condition The conductor 11 is connected through
a rectifier SR 6 to the control grid of the valve V 14, and when the
start element of a character signal arrives, a positive potential is
fed through the rectifier SR 6 and switches the multivibrator over so
that the valve V 15 becomes blocked A positive potential is thereby
applied from the anode of valve V 15 to block the rectifier SR 6 so
that the multivibrator is unaffected by the following code elements of
the character signal The multivibrator is timed to return to the
stable condition after 8 timing pulses have been generated by the
valves V 10 A and V 1 OB This is done by suitable choice of the time
constant of the coupling circuit in the well known manner.
The valve Vi 1 A is arranged as a conventional Hartley oscillator, the
anode being effectively connected to ground through the high tension
source (not shown) This oscillator should be arranged to generate a
frequency whose period is equal to one code element period For
example, if the code element period is 20 milliseconds, the Gscillator
frequency will be 50 cycles per second.
The anode of the valve V 10 A being effectively at ground potential,
the output is taken from the control grid which is connected to the
control grid of an amplifier valve V 1 OB.
which is biassed to act as a limiter, so that substantially
rectangular negative pulses of duration 10 milliseconds are supplied
to conductor 13.
e 5 The oscillation circuit of the valve V 1 OA 784,751 784,751 that
only negative pulses can have any effect.
The second negative timing pulse switches the valve V 11 back to the
original condition with the right-hand section conducting A negative
pulse is now transmitted from the right-hand anode of the valve V 11
to the control grids of the valve V 12, and switches it over to the
condition with the right-hand section cut off The corresponding
positive pulse transmitted to the control grids of the valve V 13 has
no effect.
The third negative timing pulse switches the valve V 11 again to the
condition with the right-hand section blocked No effect is produced on
the valve V 12.
The fourth negative timing pulse switches the valve V 11 again back to
the original condition The negative pulse thereby generated at the
right-hand anode of valve V 11 switches the valve V 12 back to its
original condition The negative pulse thereby generated at the
right-hand anode of the valve V 12 switches the valve V 13 over to the
condition in which the right-hand section is blocked.
Succeeding timing pulses continue the operation in the same way The
following Table Lgives the potential of the left-hand anode of each of
the three valves V 11, V 12 and V 13 after the application of each of

eight successive timing pulses:TABLE I
Each of the groups of rectifiers SR 7 to SR 13 comprises four separate
rectifiers arranged in a vertical column Group SR 14is similar to the
others except that the uppermost rectifier of the column is omitted
The three rectifiers of each group other than the uppermost rectifier
in the column will be referred to as the " three lower rectifiers "
This term will also be applied to the three rectifiers of group SR 14.
The three lower rectifiers of each of the eight groups are
respectively connected over three of the conductors 14 a to 14 f to
one of the anodes of the three valves Vil to V 13, there being a
different selection of anodes for each group The connections are shown
in the following Table II, the number of the conductor over which the
connection to an anode is made being entered in the column
corresponding to the anode.
784,751 TABLE II
V 1 i anode V 12 anode V 13 anode Rectifier Group L H R H L H R H L H
R H.
SR 7 14 a 14 d 14 f SR 8 14 b 14 c 14 f SR 9 14 a 14 c 14 f SRIO 14 b
14 d 14 e S Rll 14 a 14 d 14 e SR 12 14 b 14 c 14 e SR 13 14 a 14 c 14
e SR 14 14 b 14 d 14 f 11 1 1 1 The three lower rectifiers of each
group form a conventional coincidence gate such that a positive output
voltage is only produced from the gate if all the anodes to which it
is connected are at a relatively high positive voltage This can be
understood by considering the group SR 14 An output terminal 30 is
connected to the anodes of the three rectifiers of the group, and to a
positive source + through a load resistor In the stop condition (that
is after the eighth timing pulse) all three rectifiers of the group SR
14 are connected to positive valve anodes (see Tables I and II) All
three rectifiers are then blocked, and the source + supplies a
positive output to terminal 30 If the potential of any one or more of
the valve anodes, to which the rectifiers of group SR 14 are
connected, falls to zero, the corresponding rectifier or rectifiers of
the group will be unblocked and the potential of the terminal 30 is
then prevented from rising above zero, so no output is obtained Such a
condition occurs, for example, after the first timing pulse, when the
left-hand anode of the valve Vil is at zero potential (see Table I),
so the lowest rectifier of group SR 14 is unblocked, and no output can
be obtained at terminal 30.
The other rectifier groups SR 7 and SR 13 operate in the same way, but
each of them is provided with an isolating rectifier (the uppermost
rectifier) through which the output potential from the source +
reaches the corresponding one of seven outputs conductors 15 a to 15 f
and 15 h These seven outputs are designated 0, 1, 2, 3, 4, 5 and M.
The output of the eighth group SR 14 is taken directly to the terminal

30 and is designated H The group SR 14 is only used in a slight
modification of the embodiment to be de.
scribed later, and may be omitted if the modification is not adopted
An additional output conductor 15 g connected directly to the three
gate rectifiers of the group SR 13 is provided for the M output.
It has already been stated that in the stop condition, the right-hand
sections of all the valves V 11 to V 13 are conducting, and it will be
found that the connections to the anodes are such that only the
rectifier group SRI 4 is( connected to tliree posifive anodes (see
Tables I and II), and so this group is the only one which gives a
positive output, at terminal 30.
On the arrival of a character signal on conduc.
tor 11 (Fig 4), the timing pulses (graph B, Fig 9) are supplied to
conductor 13 and step the counter stages Vii to V 13 on in the known
way In response to the first timing pulse it will be found that a
positive output is obtained from SR 7, and then successively, in turn,
from SR 8 to SR 13, as the counter is stepped on Finally, the eighth
timing pulse restores the counter to the initial condition, and a
positive output again appears at terminal 30 Just after the appearance
of the eighth timing pulse, the multivibrator V 14, V 15, Fig 4,
restores itself and stops the oscillator V 10 A.
Thus positive reading pulses of duration substantially equal to one
code element period ( 20 milliseconds) are supplied in turn
respectively to conductors 15 a to 15 g The first is used for test
purposes, and the next five are the reading pulses corresponding
respectively to the five code elements 1 to 5, and the last reading
pulse M is used to step forward the tape 25 in the tape transmitter 5
(Figs 1 and 3), as will be explained later The six positive pulses 1
to 5 and M are shown graphically in Fig, 7.
784,751 In Fig 7 there is shown the net SM of the tape transmitte This
is controlled by the M which is supplied over condu normally blocked
valve V 7 hav ping magnet SM in series wit circuit When the M reading
after the five reading pulses 1 t ping magnet SM is operated to
forward by one step On this tal in Fig 7) are punched a series (
character signals The punched by means of peckers (not shown of
change-over contacts K 1 to the lower part of Fig 7, those responding
to spacing element character signal being changed thus be evident that
the key ch will be supplied to conductor 1 code elements being
represente pulses In the case of the incon signals supplied over
conducto and 5) the spacing code eleme represented by positive pulses.
Referring now to the combinin shown in Fig 5, which is the of Fig 1,
an incoming telegra signal arrives over conductor 11 that spacing
elements are represe tive pulses A corresponding -I signal derived
from a punched over conductor 16 Only the sig elements are punched on

the t resulting key character signal spacing code elements are rel
positive pulses There being nc in the start and stop periods, th ter
signal effectively provid elements in both these periods.
The combination of the tw "false addition" is carried out b fier
groups SR 1, SR 2, and SR 3 ness, a particular example o elements of
fliese two signals wit according to the following Tab TABLE IN.
St 1 2 3 Input Signal S M S S Key Signal (M) S M S Ciphered S S S M St
= start; Sp = stop; M =marl The groups of four rectifiers S together
form four coincidence g group of rectifiers SR 3 form two lating
output rectifiers The con connected directly to the lower 1 fiers SR
1, and through a reversi to the upper pair The conduct( nected through
a reversing valve lower pair of rectifiers SR 2, and stepping mag
reversing valves V 2 A and V 2 B connected in er 5 (Fig 1) cascade to
the upper pair, so that no reversal reading pulse is produced The
upper pair of rectifiers of ctor 15 g to a the group SR 3 are
connected over conductor ing the step 31 to a first amplifying valve V
3 A, and the 65 h the anode lower pair over conductor 32 to a second
pulse appears similar amplifying valve V 3 B The valves to 5, the step
V 3 A and V 3 B are each blocked unless a posishift the tape tive
potential is applied to the control grid pe (not shown over the
corresponding conductor 31 or 32 70 )f random key The rectifiers are
interconnected in groups tape controls of three by four conductors 33
to 36, and the ) the five sets arrangement is such that a positive
output is K 5 shown in only obtained on that particular one of these
contacts cor four conductors 33 to 36 for which both the 75 s in the
key rectifiers of groups SR 1 and SR 2 to which it over It will is
connected are simultaneously blocked.
aracter signal Ihen this positive output is supplied to that 6, the
spacing one of the conductors 31 or 32 which is cond by positive
nected to the said particular one of the con 80 aing character ductors
33 to 36 through one of the rectifiers r 11 (Figs 4 of group SR 3.
rnts are also To make this clear, suppose the input signal and the key
signal both have a mark ng gate circuit element (e g code element
period 4 of Table 85 gate circuit 6 III) Substantially zero potential
is supplied aph character over both the conductors 11 and 16 ThereL,
and is such fore positive potential will be applied from ented by posi
the anode of valve V 1 B to the upper two key character rectifiers of
SR 1, and from the anode of valve 90 l tape arrives V 2 A to the lower
two rectifiers of SR 2 All gnificant code these four rectifiers will
therefore be blocked.
tape, and the At the same time substantially zero potential is such
that will be applied to the remaining four rectifiers presented by of
groups SR 1 and SR 2 so that all of these 95 o such pulses rectifiers
will be unblocked It will be found e key charac that the only one of

the four conductors 33 Les marking to 36 which is connected to two
blocked rectifiers is conductor 34, and so a positive o signals by
potential is supplied from this conductor 100 y three recti through
the uppermost rectifier of group SR 3 3 For clear to conductor 31
Because conductor 35 is f the code substantially at zero potential on
account of 1 be assumed, the unblocking of the lower rectifiers of
group le MIII: SR 1 and the upper rectifiers of SR 2, the 105 other
rectifier of group SR 3 connected to conductor 31 is blocked, so that
conductor 4 5 Sp 35 is effectively disconnected from conductor 31.
M S M It will be found that if both the character 110 M M (M) signals
have a space element (eg code element period 3 of Table III), then
conducM S M tor 35 is the only one of the four which has a positive
potential applied to it, and again a k; S=space positive output is
supplied to conductor 31, 115 but this time through the lower
rectifier of R 1 and SR 2 the upper pair of SR 3 In accordance with
ates, and the Table III, conductor 31 will be called the I pairs of
iso "mark conductor" because the ciphered ductor 11 is signal has a
mark element under both condi 120 pair of recti tions just set out.
ng valve VIB If now the input signal has a space element or 16 is con
and the key signal a mark element (e g code V 2 A to the elements
period 2 of Table III), it will be through two seen that positive
potential is applied to the 125 character signals from conductor 71 a
will be delayed by half an element period, namely 10 milliseconds.
If regeneration is employed, the multivibrator 4 cannot be omitted 70
When regeneration is employed, a slightly different method of starting
the counters V 11 to V 13 (Fig 6) may be used In this case the
limiting amplifier V 1 OB is differently biased so that a train of
positive timing pulses shown 75 in graph C, Fig 9 is obtained The
first of these timing pulses corresponds to the first negative loop of
the oscillations of graph A, and occurs during the second half of the
start period, from 10 to 20 milliseconds 80 There is then no
negative-going pulse edge at zero time (that is at the beginning of
the start period) and the counting circuit will thus count only 7
instead of 8 during the whole character period To remedy this, a 85
negative pulse is taker from the anode of the valve V 3 B (Fig 5)
which, as already explained, goes negative at 10 milliseconds when
regeneration is used This negative pulse is supplied through an
appropriate gate 90 circuit (not shown) to the control grids of the
valve VII (Fig 6) and triggers it at 10 milliseconds It will be
triggered back again at 20 milliseconds by the trailing edge of the
first timing pulse (graph C, Fig 9), and so the 95 first or " O "
pulse supplied over conductor a has a duration of 10 milliseconds
instead of 20 milliseconds, and occupies the second half of the start
period The counting circuit thereafter counts at 20 millisecond

intervals, 100 as already explained. According to another minor
modification
of the circuits described, the rectifier SR 6 and the valves V 14 and
V 15 in Fig 4 may be omitted, and a connection taken from terminal 105
of Fig 6 through a reversing valve (not shown) to the control grid of
the valve V 8, Fig 4 Then in the stop condition, the positive
potential which appears on terminal 30 (and which appears reversed on
the grid of 110 V 8) will hold the valve V 9 in the conducting
condition As soon as the start signal is received, the valve V 8 will
be unblocked by the positive pulse applied over conductor 11, and the
valve V 9 is thereby blocked, thus per 115 mitting the oscillator V 10
A to start The first timing pulse supplied from the oscillator over
conductor 13 removes the positive potential from terminal 30, so that
the valve V 8 remains unblocked After 8 timing pulses have 120 been
counted by the counting stages V 11 to V 13, positive potential again
appears on terminal 30 and the oscillator is stopped.
The testing arrangements according to the present invention are shown
in Fig 10, 125 terminals A, B, C, D and E of which are intended to be
connected respectively to the correspondingly designated terminals of
Fig.
7 The arrangement is then that described with reference to the block
schematic circuit of 130 lower rectifiers of SRI directly from
conductor 11, and to the lower rectifiers of SR 2 from the anode of
valve V 2 A, and these are the only rectifiers to be blocked Thus
conductor 36 is now the only one which has positive potential, which
is supplied through the lowest rectifier of SR 3 to conductor 32,
called the " space conductor " Similarly if, as in period 4 of Table
III, the input signal has a mark element and the key signal a space
element, conductor 33 is the only one which has positive potential,
which is again supplied to conductor 32.
The anodes of the valves V 3 A and V 3 B are respectively connected
-over conductors 17 a and 17 b to the left-hand and right-hand control
grids of a double valve V 4 arranged as a double-stable multivibrator
The valve V 4 corresponds to the device 7 of Fig 1 In the stop
condition, there will be positive potential on the mark conductor 31
and substantially zero potential on the space conductor 32, and the
right-hand section of the valve V 4 is conducting On receipt of the
start element, which is a space, conductor 32 becomes positive, so
that a negative pulse is transmitted to the right-hand control grid of
the valve V 4, changing it over to the opposite condition Positive
potential is thus supplied to the output conductor 71 a connected to
the anode of the valve V 4 During code element period 3 (see Table
III) the output signal has a mark element and so a positive potential
now appears on conductor 31, and the multivibrator V 4 is changed back

to the original condition with the right-hand side conducting
Substantially zero potential now appears on the output conductor 71 a
Thus the output signal is delivered to conductor 71 a in such manner
that spacing elements are represented by positive pulses.
The multivibrator V 4 acts to amplify and shape the output pulses, but
is not essential.
and can be omitted In that case the output character signal can be
obtained from conductor 17 a, or its inverse from conductor 17 b.
According to a slight modification of Fig 5, a conductor 26, shown
dotted, connects conductor 13 of Fig 4 through capacitors Cl and C 2
to the control grids of the valves V 3 A and V 3 B The capacitors
differentiate the timing pulses shown in graph B, Fig 9, so that short
positive differential pulses are superimposed on the code element
pulses supplied over conductors 31 and 32 to the valves V 3 A and V 3
B These valves are in this case biased so, that they can only be
unbllo Iked when the differential pulses and the code element pulses
coincide With this arrangement the valve V 4 is triggered at the times
determined by the short differential pulses which thereby effectively
regenerate the signals Since these differential pulses coincide with
the positive-going edges of the timing pulses, it will be evident that
the output -7 784,751 Fig 1 The gate 8 comprises a group SR 5 of four
rectifiers, of which the two innermost rectifiers 44, 45 are connected
to the output conductor 19 Conductor 38 is a continuation of conductor
15 a (Fig 7); conductor 18 is connected to the five upper switch
contacts (Fig 7) controlled by the peckers of the tape transmitter
(not shown); conductor 48 is connected to a switch S (Fig 7) and
thence to conductor 16 when the switch is in position 1 as shown;
conductor 28 is connected to a combining device 40 (Fig 7) to which
also the conductor 15 h is connected Conductors 18 and 38 are
connected through a capacitor 42 to rectifier 44 and thence to
conductor 19.
Conductor 48 is connected through an isolating rectifier SR 4 b to
capacitor 42 Conductor 28 is connected through a second capacitor 43
to the rectifier 45 and thence to conductor 19 The rectifiers 46 and
47 act as dischargers for the capacitors 42 and 43.
The conductor 19 is connected to a valve V 6 which comprises the gate
9 of Fig 1, and has an alarm relay not shown, connected to the anode
output conductor 91 The conductor 71 b connected to the left-hand
control grid of valve V 4 (Fig 5) is connected through Fig 7 and
through an isolating rectifier SR 4 a to the control grid of the valve
V 6.
Under normal conditions, positive potential is applied to the control
grid of the valve V 6 either over conductor 19, or over conductor 71
b, or over both conductors In this condition the anode current holds

the alarm relay (not shown) operated During spacing periods of the
ciphered character signal, there is no potential applied over
conductor 71 b, and if during one of these spacing periods some pulse
is missing so that no positive potential reaches the rectifier group
SR 5 over any of the conductors 18, 28, 38 or 48, no positive
potential will be applied to the valve V 6 over conductor 19 Thus the
anode current will breduced and the alarm relay (not shown) will be
released, thereby giving the alarm T-is the loss of a pulse will not
be detected during the period vnhen a marking element is transmitted,
and the detection must wait for a spacing element, which will
generally be available at the right time during normal transmission
after a very small delay.
The pulse of graph a (or j) Fig 2 is supplied to the rectified SR 5,
Fig 10, from the rectifier group SR 7 (Fig 6) over conductors 15 a and
38 The pulses b to f, Fig 2, are also shown in the lower part of Fig
7, and reacz SR 5 from the rectifier groups SR 8 to SR 12 (Fig 6) over
conductors 15 b to 15 f and conductor 18 or 48 according to the
setting of the five switches The M pulse shownvm in graph k (Fig 2) is
suppled from fthe rec Ltfir group SR 13 (Fig 6) over conductor 15 h to
the device 40 (Fig 7) This device is controlled by the contacts 41
operated by the stepping magnet SM in such a way that the M pulse is
delivered to conductor 28 if the tape stepping machanism is operating
properly Thus the absence of the M pulse can be used to indicate a
failure of the stepping mechanism 70 It should be made clear that the
loss of the M pulse can only be detected if regeneration is used
whereby the ciphered character signal is delayed by 10 milliseconds
This is because the pulse M corresponds to, and occurs 75 at the time
of, the stop element, which must be a mark, and during the mark period
a positive potential is applied to the conductor 71 b Witi-the 10
milliseconds' delay, the fifth code element overlaps the M pulse, and
if 80 the fifth code element is a space and the M pulse is missing,
positive potential is withdrawn from conductors 71 b and 28, so that
the alarm relay is released.
If regeneration is not used the conductors 85 k and 28, and the device
40, may be omitted.
If the switch S (Fig 7) be operated to position 2, the pulses from the
lower contacts of the five switches are taken from the anode 90 of the
valve V 2 B over conductor 72, and in this way failure of one or both
of the valves V 2 A, V 2 B will be detected by the loss ot the spacing
pulses of the key character signal.
It will be evident to those skilled in the 95 art that the release of
the alarm relay in response to the loss of one or more of the pulses
generated by the distributor and associated circuits may be arranged
to stop the transmission by suitable arrangements 193

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* 5.8.23.4; 93p
* GB784752 (A)
Description: GB784752 (A) ? 1957-10-16
Improvements in and relating to electric lamp fittings for panel
illumination and the like purposes
PATENT SPECIFICATION 7
Inventors:-BERTRAM STEVENS, MAJOR SQUIRE and CHARLES WINTON TURNER.
Date of filing Complete Specification: Jan 10, 1956.
Application Date: Jan 26, 1955 No 2391/55.
Complete Specification Published: Oct 16,1957.
Index at Acceptance:-Classes 75 ( 3), D 4 P; and '75 ( 4), O( 8 Ht 3:
13).
International Classification: -Flb.
Improvements in and relating to Electric Lamp Fittings for Panel
Illumination and the like Purposes.
We, THORN ELECTRICAL INDUSTRIES LIMITED, a British Company, of 105-109
Judd Street, London, W C 1, do hereby declare the invention, for which
we pray that a patent may be granted to us, and the method by which it
is to be performed, to be particularly described in and by the
following statement:-
The present invention relates to electric lamp fittings for
illuminating panels and for like purposes.
A requirement exists for an electric lamp fitting which can be mounted
in an aperture in a panel and which, when so mounted, provides a
substantially hermetic seal of the two sides of the panel from one

another through the aperture, and with which the electric lamp can be
changed without breaking the aforesaid seal, and it is the principal
object of this invention to provide a lamp fitting meeting these
requirements.
According to the present invention, an electric lamp fitting comprises
a hollow cylindrical casing having an outwardlyprojecting flange
adapted to be sealed by means of a washer around an aperture in a
panel or the like, means being provided for fixing the casing in the
said aperture and compressing the washer between the flange and a
surface of the panel or the like, the casing being adapted for the
insertion of a lamp through one end thereof 2 to engage electric
contacts within the casing, one or more electrical connecting means
for making connection with one or more of the contacts passing out
through the other end of the casing, and the latter end, including the
aperture or apertures through which the connecting means pass being
sealed by means lPrice 3 s 6 d l of a member of rubber or similarly
compressible material.
The invention will be described by way of example with reference to
the drawings accompanying the Provisional Specification in which:Fig 1
is an exploded view of one embodiment of the invention; Fig 2 is a
view in section of the embodiment of Fig 1 mounted in an aperture in a
panel; Fig 3 is a view in section on the line 3-3 of Fig 2; Figs 4 and
5 are views similar to that of Fig 2, showing modified forms of the
invention; and Fig 6 is an enlarged sectional view on the line 6-6 of
Fig 5.
Referring to Figs 1 to 3, the embodiment there illustrated is for use
for so-called transillumination of a transparent panel 10 (Fig.
2), the fitting including a lamp 11 being passed through an aperture
12 in the panel Light from the lamp is transmitted through the panel
10 by repeated internal reflection and can be made available in known
manner at desired points in the surface of the panel 10 The
transparent panel is mounted behind a main panel 13 of the equipment
Devices such as instruments containing dials to be illuminated by
light from the panel 10 are mounted in the panel 13, although such
devices are not illustrated.
The panel 13 is assumed to be a part of one wall of a closed container
and it is one of the purposes of the embodiment to provide a lamp
fitting such that the inside of the container, that is to say the part
to the left of the panel 13 in Fig 2, is substantially her84,752
metically sealed from the outside air, that is to say the space to the
right of the panel 13 in Fig 2.
The fitting comprises a cylindrical casing a 14 having a flange 15 at
one end thereof The casing 14 is of a suitable plastic which is
light-transmitting and may have any desired colour such for example as

signal red The flange 15 is located within a boss 16 projecting
outwardly from the panel 13 and is sealed to the panel by means of a
rubber washer 17 The flange 15 is firmly clamped to maintain the
washer 17 in compression by means of an annular ring 18 threaded
internally and externally the external thread engaging in a
corresponding thread in the boss 16 Within the casing 14 are two
contact members 19 and 20 in the form of suitably bent strip metal
Extensions 21 and 22 respectively of the contact members pass through
slots 23 and 24 formed in the bottom of the casing 14 In order to seal
the base of the casing 14 and prevent leakage through the slots 23 and
24 there is provided a cylindrical rubber sealing member having
projecting lugs 26 and 27 The strips 21 and 22 project through slots
formed in the lugs 26, 27 of the member 25 The rubber sealing member
25 is provided with an annular ridge 251 (Fig 1).
In order to retain the rubber sealing member 25 and compress and
deform it in such a way as to provide the required seal, there is
provided a metal cap 28 of generally cylindrical shape having its
upper edge inwardly turned as indicated at 29 The edge 29 is crimped
over to engage in a groove 30 (Fig 1) in the casing 14 after the cap
28 has been pressed on to the end of the casing 14.
The base of the cap 28 is apertured to pass the two lugs 26 and 27 and
is inwardly dished as shown in Fig 2 Thus when the cap 28 is pressed
into position, pressure is exerted upon the member 25 in a region
around the lugs 26 and 27 and close to these lugs The lugged surface
of the member 25 which was previously flat is thus deformed as shown
in Fig 2, thereby achieving the desired compression of the sealing
member around the strips 21 and 22 The ridge 25 ' also becomes
flattened and provides a seal around the strips 21 and 22 against the
base of the casing 14.
The lampholder comprises an opaque knob 31 having a screw-thread 32
which engages in the internal thread of the annular ring 18 To the
knob 31 is fixed a metal shell 33 the central part of which is cut
away to form windows and leaving portions 34 Rio which are of only
sufficient width to give the structure sufficient strength In this way
the windows Drovided are as large as possible The free end part of the
member 33 is slotted at 36 in order to produce 635 tongues 37 which
can engage firmly the conducting side of a lamp, the conducting side
constituting one terminal of the lamp.
When the lamp is to be inserted it is placed in position in the
slotted part 35 of the lampholder and the knob 31 is screwed 70 into
position The part 35 then engages within and makes contact with the
contact member 20 while the central contact of the lamp makes contact
with the contact member 19 It is arranged that when the lamp 7 a is in
position its filament is located opposite the centres of the windows

in the shell 33 and in line with the medial plane of the transparent
panel 10 in Fig 2.
It will be evident that with the arrange 50 ment described the inside
of the casing 14 is hermetically sealed from the inside of the
container bounded by the panel 13 and moreover that the lampholder
with its lamp can be removed without breaking the seal 55 With a
pressure difference between the two sides of the panel 13 of 20 lb per
square inch it has been found that leakages not exceeding 1 c c per
hour are obtainable.
In Figs 4 to 6 like parts are given the go same references as in Figs
1 to 3 The arrangement shown in Fig 4 is intended to emit light from a
lamp 11 through a cupshaped translucent member 38 which may be
coloured as desired The casing in this case 145 is also of insulating
material and is indicated by the reference 39 The arrangements for
sealing the base of the casing are the same as described in Figs 1 to
3 The contacts 19 and 20 are also as previously described 100 The
cas'ne 39 is externally threaded to engage a threaded aperture in the
panel 13 and has a flange 40 which engages the front face of the panel
13 and is sealed with respect thereto by a washer 41 The casing is
locked 1 o 5 in position by means of a lock nut 42 The lampholder 43
has a flange 44 and a portion of similar construction to the slotted
portion 35 in Fig 1, this portion serving to make contact with the
outer cylindrical contact 110 surface of the lamp 11 and also with the
contact member 20 A knurled ring 46 having an inwardly-projecting
flange 47 serves to clamp the flange 44 against the end of the casing
39, a washer 48 being interposed for 115 sealing purposes The
translucent cover 38 is a push fit on the portion 49 of the member 43.
The arrangement of Figs 5 and 6 differs from that of Fig 4 in the
following respects 120 The flange 40 of the casing 39 is provided, in
addition to the washer 41, with a further inset washer 50 which is
engaged by and sealed against a knurled ring 51 screwed on to the end
of the casing 39 A metal mem 125 ber 52 corresponding to the
lampholder 43 in Fig 4 is fixed as by welding to the knurled ring 51
The member 52 has an end wall provided with apertures 53 which
co-operate with further apertures 54 formed in the end 134) 784,752
784,752 of a metal thimble 55 which is disposed within a translucent
cover 56 corresponding to the member 38 in Fig 4 A pin 57 is fixedly
mounted by screwing into the cover 56 and 3 works in a slot 58 (Fig 6)
in the member 52, limited rotary movement of the cap 56 being thus
permitted In this way the degree of overlap of the apertures 53 and 54
can be adjusted and hence the light transmitted through the cover 56
can be adjusted by rotating the cover 56.
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* 5.8.23.4; 93p

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