4951 4955.output

* GB785358 (A)
Description: GB785358 (A) ? 1957-10-30
Improvements relating to fire-extinguishing installations
Description of GB785358 (A)
PATENT SPECIFICATION
Inventors: THOMAS ANTHONY HENSHAW and WERNER ROHR 785,358 Date of
filing Complete Specification: Aug 23, 1954.
Application Date: Sept 2, 1953 No 24301153 Pl Complete Specification
Published: Oct30, 1957.
Index at acceptance:-Classes 47, A 14 (E 2: H: J); and 135, P( 1 E: 3:
6: 14: 18: 19), P 24 (F: KX:
X), VD 7 A.
International Classification:-A 62 c F 06 k.
COMPLETE SECIFICATION Improvements relating to Fire-Extinguishing
Installations We, THE PYRENE COMPANY LIMITED, a British Company, of
Great West Road, Brentford, Middlesex, 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
fire-extinguishing installations of the kind in which a container, or
more usually a battery of containers, of carbon dioxide or other
gaseous fire-extinguishing agent under pressure is connected to a pipe
system leading to different points of risk When a fire breaks out at
one point the fire-extinguishing agent must be directed to it, so a
series of distributing valves is often provided, all these valves
being normally closed and the appropriate valve being opened on the
outbreak of fire by the falling of a weight, itself released through a
fusible link or an electrical detector.
According to this invention gas operated distributing valves, one for
each point of risk, each have two pairs of inlet and outlet ports,
each port being independent of all the others, and the ports of each
pair being isolated from each other when the valve is in the closed
position and in communication with each other when in the open
position.

These pairs of ports provide passages for respectively the flow of gas
to gas operated mechanism for opening the container or containers and
for the flow of the fire extinguishing agent on release The
connections are such that when fire occurs at a point of risk gas,
released manually or automatically, moves the distributing valve for
that point of risk to the open position so that it thereupon flows
through one pair of inlet and outlet ports to operate the mechanism,
and that the fire-extinguishing agent released thereby then flows to
the distributing valve, passing unrestrictedly through the other pair
of inlet and outlet ports in the distributing valve opened by the
operating gas Thus the distributing valves are not under pressure
while being opened If they were, the seals in them, especially if they
were rings of cir SO cular cross-section, would be damaged.
The gas released to flow to and open the distributing valve may be
stored in a relatively small pressure container associated with that
distributing valve, there being as 15 many such containers as there
are distributing valves The appropriate container is opened upon the
outbreak of fire either manually or automatically.
Alternatively there may be only one such 60 container supplying gas to
all the distributing valves, and pilot valves in pipes leading from
this to the respective distributing valves may be provided, each pilot
valve being associated with one point of risk and 65 opened manually
or automatically A single container supplying gas to pilot valves may
be one of a battery of containers of fireextinguishing agent.
The preferred form of distributing valve 70 is a piston valve
comprising two pistons on a spindle in a casing with four ports placed
so that the incoming gas released upon the outbreak of fire enters
through one port and moves the valve to allow the gas to escape 75
from the valve through the second port and to flow to the operating
mechanisms of a battery of containers; and that during the movement of
the valve the other two ports, which are normally shut off from one an
80 other, are put into communication with one another.
Some installations according to the invention will now be described by
way of example with reference to the accompanying 85 drawings, in
which:
Figure 1 is a diagram showing the connections in one installation;
Figure 2 is an enlarged longitudinal section through the preferred
form of distribut ge ing valve; Figure 3 shows a second installation;
and Figure 4 shows part of Figure 3 on a larger scale.
The installation shown in Figure 1 is intended for the protection of
two points of S risk, shown as two rooms A and B In each there is a
detection system comprising a wire 1 anchored at one end to a wall 2
and runfling over pulleys 3 to a weight 4, which it supports Fusible
links 5 are inserted in this wire to be fused on the outbreak of fire.

When a link 5 fuses, the weight 4 falls and rocks a lever 6 forming
part of a toggle mechanism 7 by which a small cylinder 8 of compressed
carbon dioxide is opened when the lever rocks The carbon dioxide
thereupon flows through a pipe 9 to a distributing valve 10.
A battery 11 of containers of compressed carbon dioxide is provided
for extinguishing any fire that may break out in either room.
Each container is provided with a gas-operated mechanism for piercing
a diaphragm sealing the container This mechanis m may be of any
convenient kind but preferably is constructed as described in our
Application No 20,826/53 (Serial No 770,276) The battery 11 is shown
purely diagrammatically in Figure 1, each container of it being much
larger than the cylinder 8.
The function of each distributing valve 10 is first to lead the
released carbon dioxide from the cylinder 8 to the battery 11 to
operate the piercing mechanisms and then to lead the carbon dioxide
released from the battery 1 1 to the room in which the fire is
burning.
A valve 10 is shown in detail in Figure 2 It comprises a pair of
pistons 12 and 13 on a spindle 14 in a casing 15 The spindle has an
extension 16 carrying another pair of pistons 17 and 18 The casing 15
has four ports 19, 20, 21 and 22 The incoming -gas released upon the
outbreak of fire and arriving through the pipe 9 enters through the
port 19 and acts on the piston 18, thu S moving the valve to allow the
gas to escape from the casing through the port 20 and to flow to the
operating mechanisms of the battery 1 1 through pipes 23, 24 and 25
During the movement of the valve the other two ports so 21 and 22,
which are normally shut off from one another by the piston 13, are put
into communication with one another.
The gas released from all the containers in the battery 11 flows into
a manifold 26 and from it to the port 21 It passes through the valve
10 and out through the port 22 to a pipe 27 which terminates in a
discharge nozzle 28 through which the gas is ejected into the roomi A
or B as the case may be.
In each valve 10 the upper end of the casing 15 is closed, so that the
valve spindle -With its pistons is directly moved axially ag 2 ainst
an air cushion trapped between the clo Sed end and the piston 12.
Once gas under pressure has entered the pipe 23, it flows to the other
valve 10 It must not escape through this, and it is for this reason
that the piston 17 is provided.
This piston prevents the flow of gas from the port 20 to the port 22
so long as the 70 piston assembly is in the closed position.
It is desirable to allow any surplus gas from the small cylinder 8 to
escape For this purpose there may be a bleed from the pipe 9 to the
atmosphere or into the manifold 26, 75 or there may be an escape valve

which can be opened -manually, but an automatic valve is preferred
This is shown in Figure 2, where the distributing valve 10 has a
restricted passage 29 leading from the interior 80 of the casing to a
bore 30 A transverse bore 31 connects the bore 30 to the port 20, and
is controlled by a small valve 32 which is normally closed by a spring
33 This valve 32 moves aggainst the spring when the pressure 85 in the
manifold 26, and therefore in the casing 15, rises, so that gas can
then bleed from the pipe 9 into, the casing 15.
After the apparatus has operated the valve 32 is re-set by the spring
33 The valve stem 90 34 projects from the casing 15, and its position
therefore shows whether the valve is open or closed.
The valve spindle 14 in the valve 10 has an indicating head 35 which
clearly shows 95 the position of the piston assembly within the casing
All the pistons carry sealing rings 36 of circular cross-section, and
it will be observed that there is no risk of these being damaged
during movement of the 100 valve, since the carbon dioxide under very
high pressure cannot enter the casing 15 until the valve has been
moved by the action of the carbon dioxide arriving through the pipe 9
1 os A reserve battery 37 is provided in case a second fire breaks
out, and can be opened by gas from another small cylinder 8 on a valve
38 being opened Handles 39 are provided by which both batteries can be
oper 110 ated manually if required.
Figures 3 and 4 show anl installation in which there are three points
of risk (not shown) and three distributing valves 10, each constructed
as shown in Figure 2 In 115 this case, the gas for operating the
distributing valves comes from one of the containers of a battery 40
The container thus initially opened, which may be called the pilot
contaimer, is shown at 41 120 It is necessary to ensure that the pilot
container 41 is opened if fire breaks out at any of the three points
of risk Three fusible Ilmn-s 42, one at each point, are indicated
dia-aiirnqatically in Figure 3 and control three 125 we,,Zits 43, all
connected to ai lever 44, which is ffic equiv-ale-nt of the lever 6
sihown in Flele 1 Thus the fusing of any of the links 42 I open the
container 41.
it 1 n'zc-essarv to ensure that the gas re 130 785,3508 of all the
containers of the battery, together with connections from the
distributing valves running to appropriate points in the pipe This is
illustrated in Figure 3, in which it is assumed that the risks served
by the 70 two left-hand pipes 66 require all six containers of the
battery 40, but the risk served by the right-hand pipe 66 requires
only three containers The pipe 64 does not directly connect the two
left-hand pipes 62 with the 75 right-hand pipe 62, and a non-return
valve 67 being inserted in it between the two middle containers of the
battery 40 to allow flow from left to right but not from right to left

Then if the fire breaks out at points 80 served by either of the two
left-hand pipes 66, the gas from the pilot container 41, after flowing
through the corresponding valve 10, will travel through the pipe 64 in
the direction shown by the arrow X, and flow through 85 all the
mechanisms 65 to open all the containers of the battery 40 If,
however, the fire breaks out at the point served by the right hand
pipe 66, the gas from the container 41, after leaving the right-hand
valve 90 10, will flow through the pipe 64 in the direction shown by
the arrow Y, and will open only the two unopened containers in the
right hand part of the battery and operate the mechanism 60 to allow
the gas in the 95 container 41 to flow to the manifold 56 The valve 67
stops the gas from flowing to the containers in the left-hand part of
the battery.
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* GB785359 (A)
Description: GB785359 (A) ? 1957-10-30
Improvements in or relating to a driving mirror device particularly for
automobiles
Date of Application and filing Complete Specification: Feb 15, It /Com
Application made in France on April 30, 1953.
/Complete Specification Published: Oct 30, 19.
785,359 No 4370154.
954.
57.
Index at acceptance:-Classes 97 ( 1), B 7 R, J 18 A; and 103 ( 2), C

9.
International Classification:-BO 2 d, C 02 b, d.
COMPLETE SPECIFICATION
Improvements in or relating to a Driving Mirror Device particularly
for Automobiles I, PAUL JOUVIN, a French Citizen, of 5 Villa Lambert,
Chatou, France, do hereby declare the invention, for which I pray that
a patent may be granted to me and the method by which it is to be
performed, to be particularly described in and by the following
statement: -
The purpose of the present invention is to create a new driving mirror
device particularly intended to be mounted on automobile vehicles.
Driving mirrors, as generally used, consist simply of a mirror which
reflects images seen through the back window of the vehicle on which
it is mounted This view is limited by the dimensions of the window and
this drawback is still increased when passengers are occupying the
rear seats in the vehicle.
When it rains or snows, the rear window is most often made opaque,
which completely prevents vision through it This drawback is
particularly serious, inasmuch as the driver cannot know whether there
are any vehicles behind him, so that he is in danger of making
mistakes in driving, which may be very serious, particularly when
another vehicle is trying to pass him at the time.
The present invention obviates these drawbacks by creating a new
driving mirror device, particularly for automobiles and the like
applications.
According to the invention, the driving mirror device, particularly
for automobile vehicles, is characterized by the fact that it
comprises a divergent objective with its axis substantially parallel
with the direction followed by the vehicle, a plane mirror having the
normal at its centre making an acute angle with said axis so as to
reflect obliquely the rays going through the divergent objective and
arranged at the back of said objective, and a convergent eye-piece
arranged symmetrically to the divergent objective with respect to the
normal issuing from the centre of the mirror which compels the rays
refleclPrice 316 l ted by the latter to go through said eye-piece,
giving an enlarged image of an object, such as a following vehicle,
placed in front of the divergent objective.
Various other features of the device ac 50 cording to the invention
will appear from the following detailed description.
One form of embodiment of the object of the invention is represented
by way of nonlimitative example, in the appended drawing 55 Fig 1 is a
front elevation of the driving mirror device of the invention; Fig 2
is a section, on a larger scale, taken along line II-II of Fig 1:
Fig 3 is a diagram illustrating the path of 60 the light rays through

the back sighting device of the invention; Fig 4 is a curve showing
the variation of the size of the images obtained in terms of the
distance separating an object from the 65 back sighting or driving
mirror device; and Fig 5 shows, in plan, two automobile vehicles, one
of which is provided with the device of the invention.
The driving mirror device of the invention 70 comprises, as shown
particularly in Figs 1 and 2, a casing 1, connected with the element
supporting it, with a door jamb 2, for instance, by any suitable
means, as by a sleeve 3 or a yoke clamped by means of a suitable 75
element 4, making it possible to adjust the location of the housing
according to the position occupied by the driver of the vehicle
provided with the device of the invention 80 In case the door of the
vehicle on which the casing is mounted comprises a deflecting shutter,
as is current in modern automobile vehicles, said shutter and/or
casing are so shaped as to allow the free pivoting of said 85 shutter
as well as its closing.
The portion of the casing 1 which is placed outside the vehicle and
designated by reference 5 offers an aperture 6, in which a divergent
lens 7, is arranged, constituting the 90 785,359 objective of the
device.
The casing 1 comprises, on the other hand, a tubular portion 8 which
is located inside the vehicle This portion also offers an aperture 9,
in which a convergent lens 10 is arranged.
The bottom of the casing is used as a support of a plane mirror 11
intended for reilecting the rays going through the divergent lens 7 to
the convergent lens 10.
The divergent lens 7 serves, as explained above, as an objective lens,
and the lens 10 as an eye-piece As can be seen, particularly in Fig 3,
the angles a, made by lenses 7 and 10, respectively, with the mirror
11 are equal The magnitudes of these angles depend on the
characteristics it is desired to obtain from the driving mirror device
By way of example, these angles may be 35 .
According to a preferred embodiment, the focal length of the divergent
lens 7 is so selected that an automobile vehicle placed at a distance
of 100 m from this lens will be seen by an observer as an image 3 mm
high.
As shown in Fig 4, in which there are plotted as abscissae the
distance in meters, separating the driving mirror device from the
object to be observed and, in centimeters, the apparent magnitudes of
the image received, the curve shown is obtained, which shows,
consequently, the variation in magnitude of the image, as a function
of the distance from the object to be observed.
Similarly, the focal length of the convergent lens 10, is so chosen
that the observer, who, normally, is the driver of the vehicle on

which the device of the invention is mounted, has a total vision of
the image when he is at a distance of 30 to 40 cms from the device.
As is well known, the divergent lens 7 gives an upright virtual image
of the object coming from the rear The mirror 11 reflects the rays
received from the image towards the lens 10, by which the reflected
image is enlarged and received by the observer.
In Fig 3 there is shown at A-B the virtual image produced by the lens
7 of the object to be observed, and at Al-B 1 and A 2-B 2 the
reflected image, as seen by the observer through the eye-piece 10, at
two different distances of the object from the device.
Fig 5 illustrates the manner in which the driver of the vehicle,
designated as 12 sees a vehicle 13 making ready to pass him.
It is quite obvious that the shape of the driving mirror device as
well as its mode of attachment and also the lens characteristics may
vary in various manners, according to the particular applications for
which the driving mirror device is intended.
By way of example, it has been noticed that it is advantageous, in
some cases, that the divergent lens have a diameter of 6 cms.
and a focal length equal to 120 mm while the convergent lens is 7 5
cms in diameter and has a focal length equal to 260 mm the angles a
being obviously equal and 30 in magnitude The area of the convergent
lens is greater than that of the divergent lens 70 The invention is
not limited to the example of embodiment represented and described in
detail, as various modifications mav be made thereto within its scope
In particular, the above described device is designed for 75 being
placed on new cars on which its use has been intended On existing
cars, the apparatus, when necessary, may remain entirely outside, the
convergent lens being placed near the window of the car, or before 80
the windshield, under the direct vision of the driver Similarly, the
supporting housing for the lenses and mirror may possibly be used for
supporting various accessories such as parking lights, headlights etc
85
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* GB785360 (A)

Description: GB785360 (A) ? 1957-10-30
Improvements in or relating to clockwork control mechanisms
785,360 Date of filing Complete Specification June 9, 1955.
Application Date March 9, 1954 No 67911 Complete Specification
Published Oct 30, 1957.
Index at acceptance: -Class 10, F 2 A.
International Classification: -F 02 j.
Improvements, in or relating to Clockwork Control Mechanisms 54.
We, S DAVALL & SONS LIMITED, a British company, of 264, St John
Street, London, E.C 1, and GREGORY KRIVOCHEEF, a citizen of the French
Republic, of the company's address, 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 comprises improvements in or relating to clockwork
control mechanisms.
In clockwork mechanisms it is known practice to drive two adjacent
trains from separate mainsprings, or to drive one train from the
toothed periphery of the barrel and another from a toothed wheel
attached rigidly or by pawl and ratchet to the barrel arbor and to
provide means whereby one train, normally still, hereinafter called
the " functional train ", is set in motion from the other, normally in
motion, hereinafter called the " going train ".
The present application relates to improved methods of interconnecting
and mutual control of two such trains.
According to one feature (of the present invention clockwork-control
mechanism for a "functional train " operable from a " going train '
comprises in combination a stop-member for the " functional train ", a
release-cam operated by the " going train " and connected to the
stop-member to withdraw it from stopping position and subsequently
re-set it for return thereto, and a hold-off cam operated by the "
functional train " to keep the re-set stop-member out of operation
until the ; functional train " has completed a cycle of movement In
this way the " functional train" can be made to effect an exact cycle

of movement each time it is released and then be stopped until it is
again released by the " going train ".
In the preferred construction, hereinafter described, the stop-member
is mounted on a stop-lever, which is movable in one dimension, to
withdraw and replace the stop and in a second dimension by the
hold-off cam, and the release cam is connected to the stop-lever
lPric_ through a release lever which actuates the stoplever in the
first said dimension while permitting its movement in the second said
dimension under the operation of the hold-off cam.
The following is a description by way of example of one construction
in accordance with the invention: In the accompanying drawings, Figure
1 is a diagram showing the setting out of two clockwork trains in
accordance with the invention; Figure 2 is an expanded section upon
the line 2-2 of Figure 1; Figure 3 is a front elevation of the
mechanism; Figure 4 is a diagram of parts of the mechanism, and Figure
5 is an external elevation of a case for the mechanism, showing the
controls.
The mechanism comprises two plates 11, 12 (Figure 2) which support a
spring-arbor 13 on which is a barrel 14 containing a large driving
spring The front end of arbor 13 is supported by a quarter-plate 15
(Figure 3) carried by posts in front of plate 11 The arbor 13 carries
teeth 16 which mesh with a " going train " 17, 18, 19, 20, 21 leading
to a jewelled lever escapement of which the balance wheel 22 is seen
in Figure 3 On one spindle 23 of this train, which carries wheel 19
and rotates once per hour, is a release cam 24 which has five release
notches 25 equidistantly spaced around its periphery to cooperate with
a release cam-lever 26 fixedly mounted on a freely rotatable spindle
and, as long as the mechanism is operating, to actuate it every twelve
minutes The barrel 14 carries a large wheel 27 which drives a second
gear train called the " functional train " and comprising wheels 30,
31, 32, 33 The "functional train " may be regulated as desired and is
shown as regulated by an escapement assembly 34.
The release-cam lever 26 releases the "functional train " 30-33 to set
it in motion once every twelve minutes through a release 2 t 785,360
mechanism such that, when the " functional train" has driven its
mechanism through a complete cycle it will stop and re-set the release
lever 26 in readiness to be re-started by the " going train " upon the
completion of the twelve-minute interval, as hereinafter described.
The " functional train " has, on the spindle which carries wheel 32 of
the train, two cams 36, 37 which rotate once for a complete cycle of
the functions performed by the train.
As will be evident hereinafter, the time of this cycle must be less
than twelve minutes, or if it is longer the release cam 24 must have
fewer notches.

Figure 4 of the drawings shows in full lines the parts of the transfer
and control mechanism which are in front of the front plate 11, except
the cams 36, 37, gear wheel 76, section 45 of cam 37 which are taken
away to show the mechanism beneath them, and are only indicated in
chain line The release cam 24 and certain associated parts, being
behind plate 11, are shown in dotted lines; the barrel and spring is
assumed to be removed.
The release lever 26 carries a pin 28 with a sharp edge to drop into
the release notches and it has an arm 29 which is drawn by a spring 39
in such a direction as to urge the pin 28 into the notches The end of
the lever arm 29 carries a pin 40 which works in a slot in a
bell-crank-shaped stop-lever 41, which has a wire spring 42 on its end
to bear lightly on the edge of the balance wheel 44 of the escapement
34 of the "functional train".
Lever 26 is shown in Figure 1 with the pin 28 out of any notch,
resting against the edge of cam 24, and the wire 42 resting against
the edge of the balance wheel 44 When the pin 28 on lever 26 drops
into any notch 25, it brushes the wire 42 on the stop lever away from
the balance wheel and starts the " functional train " going.
Stop lever 41 is pivoted on an arbor 43 which is free to slide endwise
through the plate 11 and is urged by a spring to bear on the rear face
of cam plate 37 The cam has a sloping section 45 and at the end of a
rotation of the arbor 35 the arbor 43 drops onto the slope 45 and
brings the brush 42 against the balance wheel 44 When however the
lever 26 operates and rotates the stop-lever 41 to start the
"functional train" as already described, the slope 45 of cam 37,
because of its rotational motion presses the arbor endwise and takes
the wire 42 out of the way of the balance wheel before the pin 28 on
lever 26 lifts out of notch 25, and holds it out of the way until the
"functional train" has completed its cycle The rear face of cam 37
with its slope 45 may thus be described as a hold-off cam, i e it
holds the brush 42 from the wheel 44 although the stop-lever 41 is in
its position for holding the brush against the wheel, which actuates
the stop-lever axially while the release cam operates it in a plane
parallel to plate 11.
With the mechanism as so far described, if the "going train" is
running and driving release cam 24, the " functional train " will be
70 automatically set going and will complete one cycle and stop,
repeating this once every twelve minutes Cam 36 has an edge which is
shaped to actuate a transmitter which will send out a " distress "
signal (e g " S O S ") 75 and to give other data (e g ship or aircraft
recognition signal) automatically by operating a key-switch 50 (Figure
3) Reference hereinafter to a " distress cam " means cam 36 The
details of shape are not shown in the drawing 80 Normally this signal

and data occupy much less than the twelve minute cycle and therefore
the cam 36 and switch 50 are arranged so that the cam 36 completes a
rotation in the requisite time for the signal, and so that the 85
power supply (e g from a battery) is cut off when the signal is
finished The cam and switch therefore are made to switch the power
supply on again when the " functional train " movement recommences,
and to allow time enough 90 for the valves of the transmitter to warm
up before the cam causes the " distress " signal to begin This
economises power considerably, and also spring-power, as the spring in
barrel 14 has, for most of the time, to drive only the 95 " going
train" to release cam 24.
The front face of cam 36 carries a camprojection 136 which operates a
set of contacts on a switch 152 as soon as the cam is started This
puts the power supply in cir 100 cuit and applies a boost voltage to
transmitter valve heaters for up to 10 seconds, which is the time
taken for the cam projection 136 to disengage from the switch contacts
150 The same projection 136 engages in a like manner 105 with switch
contacts 151 and performs the same functions when the cam 36 is
advanced to the alarm starting position It will be understood that
there is another switch behind the switch 50 for operating on the edge
of 110 cam 37.
In order to start the "going train", a spindle 51 (Figure 4) is
provided, which carries an operating lever 52 This bears on a pin 53
on an intermediate lever 54 The 115 lever 54 is connected by a link 55
to member 56 carried on one end of an arm 57 which is free to rotate
on the arbor 23 on which the release cam 24 is mounted The arm 57 has
at its other end a pin 58 working in a slot 59 120 in a starting lever
60 The starting lever 60 carries a wire 61 to bear on the edge of
balance wheel 22 Therefore, rocking the lever 52 to the right as
viewed in Figure 4, into the chain line position, will rock the
starting lever 60 125 and start the train; bringing it back will stop
it The starting lever 60 has a projection 160 which engages a catch
161 fixedlv mounted on the spindle of the release lever 26 This
prevents the release lever dropping into a 130 785,360 notch 25 if the
lever 60 is brought back to stop the " going train " at a position
where a notch happens to be beneath the pin 28 Thus the " functional
train " is prevented from working if the " going train " is stopped.
The member 56 itself constitutes a short lever pivoted on the end of
arm 57 and its spindle passes through arm 57 and slot 62 in plate 11
into the plane of cam 24, where it carries a hook 63 adapted to drop
into one of the notches 25 The cam 24 is not fast on its arbor 23, but
carries a pawl 64 which is driven by a ratchet-wheel 65 on the arbor;
it can therefore over-run the arbor When the operating lever 52 is
operated therefore, if the cam 24 is not in a position where it

immediately lets the lever 26 fall into a notch, the hook 63 will pull
it forward into the appropriate position and signals will commence
without delay To ensure that this happens the travel of hook 63 and
lever 57 is at least equal to the distance between two adjacent
notches 25 which in the construction being described is a fifth of the
turn of cam 24.
The edge of cam 37 is shaped to operate mechanism which will emit
wireless signals for an alarm (twelve dashes at accurately timed
intervals) Reference hereinafter to an " alarm cam " means cam 37 The
alarm is necessary to alert signal receiving stations (e.g one located
on another vessel or on an aerodrome) to the distress signals about to
be transmitted To this end the operating lever 52 is moved to the "
alarm position " counterclockwise from the position shown in Figure 4,
against a pin 73 on a quadrant arm 74 which has a toothed segment 75
to mesh with a gear 76 rotatable freely about the spindle 35 which
carries the cams 36, 37 The gear 76 is fast with an arm 77 on the end
of which is a spring plunger 78 capable of operating, close beside the
arbor 43, on the slope 45 of cam 37 If the operating lever 52 is moved
to the left, it moves sector 75 to the right and carries round the
plunger 78 to the left and with it the cams 37 and 36, the object
being to bring the cam 37 into a suitable position to start the alarm
When lever 52 operates quadrant 74, i e to set the alarm in operation,
the "going train is not released as only one sequence of the "
functional train " is reqyired.
Quadrant 74 moves cams 36 and 37 through an arc restricting the
distance in time between a complete distress sequence and the alarm
sequence This is possible due to the action of a pawl 64 and the
ratchet wheel gear 76.
The alarm signal does not occupy a full turn of the cam and by
starting the cam round in this way the termination of the signal can
be made to coincide with the end point of the movement, where the
arbor 43 stops the balance 44 It will be appreciated that the initial
rotation of the cam 37 also presses back arbor 43 by the action of
slope 45, this disengages the stop spring 42 from the balance 44 and
leaves the balance 44 free to start.
This initial rotation continues until a spring latch 79 on the back of
cam 36 passes a pin on quadrant 74 The movement of the quadrant will
have brought the pin 80 into the 70 chain line position shown when the
latch 79 passes it, and the pin will stop further movement by engaging
the face of a second spring latch 81 on the back of the cam 36
Thereupon the latch 79 will spring out behind the 75 pin and prevent
any rebound When the lever 52 is let go, a spring 82, which connects
lever 54 and quadrant 74, will draw the quadrant back and move the pin
80 out of the space between latches 79 and 81, leaving the cams go

free to move.
Although the balance wheel 44 is left free to move by the axial
movement imparted to the stop-lever 40, there is a risk that it may
not actually start, if the escapement is at a 85 dead-centre point To
obviate this a lever 83 is pivoted on plate 11 and held by a spring 84
so that its end projects into the path pf the end of the arm 77 The
arm 77 gives lever 83 a flick as the quadrant 74 returns arm 77 to 90
the position shown in Figure 4 The spindle of lever 83 on which the
latter is fixedly mounted passes through plate 11 and carries an arm
86 which has a wire 87, normally clear of balance wheel 44 but capable
of brushing 95 its edge when the arm 77 is flicked flicks the lever 83
This ensures that the balance starts.
It will be observed that the "alarm" is given without starting the "
going train ", which is only used for the " distress " signals 100 of
cam 36.
A further feature of this invention is the automatic change-over
electrically of the contacts operating on the " distress" cam 36 and
the contacts operating on the "alarm cam 105 37 and vice versa.
Referring again to the drawing Figure 4 a lever 94 is fixed on a
spindle 95 which passes through plate 11 and behind it carries a
switch-operating lever 96 A change-over 110 switch (pot shown) is
secured on the back plate 12 of the mechanism, so as to be operated by
lever 96 When the mechanism is not operating, or when it is operating
in the " distress " signal transmission position, the 115 lever 94 is
held by a spring 97 When the quadrant 74 is moved to the " alarm "
position by starting lever 52, the lever 94 is moved by a cam
projection 89 on the quadrant 74 and actuates the switch-operating
lever 96 This 120 disconnects the " distress " signal switch contacts
and connects the " alarm " signal switch keying contacts The lever 94
is held in the " alarm " position by means of a pawl 98, which is
pivoted on the end of the lever 94 125 and which engages with a
catch-pin 99 fixed to the plate 11 of the instrument When the cam
assembly 36, 37 reaches within 30 of its maximum travel of 1
revolution, a pin on the underside of the cam 37 encounters the 130
tip of the pawl 98 and moves it clear of its catch-pin 99, whereupon
the levers 94 and 96 return to their normal position and put the
switch contacts back to the "distress" position in readiness for the
next cycle.
All the above described parts are placed within a water-tight case 100
(Figure 5) The spindle 51 on which the operating lever 52 (Figure 4)
is fixedly mounted, passes through the front of the box and carries an
operating handle 101, which can be moved to " alarm " and "distress"
positions, but is normally centred in the position shown The
springarbor 13 carries a square for a key 103 for winding up The lever

101 is retained, when moved to the " distress " position, by a catch
which can be released by a push-button 104.
In Figure 4 it can be seen that push-button 104 is mounted on a
catch-lever 105 the end of which falls behind the intermediate lever
54 when the latter has been moved to the chain line position A
suitable spring behind the push-button ensures this In addition, the
case 100 carries a turn-switch handle 106, connected to a switch 107
shown in Figure 3 by a spindle 108, for the purpose of connecting the
instrument to a main or emergency battery, or to another alternative
supply or of cutting off the current.
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* GB785361 (A)
Description: GB785361 (A)
No title available
Inventors: RONALD WILLIAM FENEMORE and COLIN RODERICK BORLEY785,361
Date of filing Complete Specification March 9, 1955.
Application Date March 15, 1954.
Complete Specification Published Oct 30, 1957.
No 7442/54.
ndex at Acceptance:-Classes 40 ( 1), H 11 B( 15: X); and 83 ( 3), W 18
(A 2 B: B 5: B 6: C 2: E 2).
nternational Classification: -B 23 c G 08 c.
Improvements in or relating to Automatic Interpolation and like
Systems We, THE MULLARD RADIO VALVE COMPANY LIMITED, of Spencer House,

South Place, Finsbury, London, E C 2, 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 interpolation systems and to automatic
systems for generating, reproducing, or checking contours or profiles
and like operations.
Interpolation means according to the invention may be used in a
general way for analogue interpolation between points specified
numerically For example such means may be used as a smoothing device
for data issuing from digital calculators.
The invention is suitable inter alia for application to automatic
control of machines for milling or cutting contours and profiles of
large articles, for example aircraft wing spars or control surfaces,
and aerofoil models It is also suitable for application to the
machining or checking of smaller articles of complex curved shapes
such as turbine blades.
In a known automatic aircraft spar milling system, a full scale model
of each type of spar is required to provide a master contour.
The contour of the model is followed by a follower the movements of
which guide and control the progress of a carriage carrying the
cutting to 3 l Such a copy-milling system has the disadvantage that an
accurate and durable scale molel of each type of spar must be
constructed prior to manufacture even of a prototvpe, and the models
of all tvpes not actually in production have to be carefully stored.
It is an object of the present invention to provide improved analogue
interpolation means and it is a further object of the invention to
provide an improved automatic contour or profile generating,
reproducing or checking system capable of a high degree of accuracy
lPnce 3 s 6 d l which system does not require the provision of any
permanent physical models of desired contours or profiles Instead, an
adjustable profile member is provided which member can be set up so as
to act as a temporary representation or scale model of a desired
contour or profile existing solely as a set of numerical data.
According to one aspect of the invention apparatus for analogue
interpolation comprises a leaf spring or other flexible elastic scale
modei, a pair of spaced mounts therefor in relation to one or each of
which the scale model is slidable longitudinally, means for effecting
adjustment of the position of said mounts in relation to each other
and of at least one mount in relation to a predetermined co-ordinate
or reference, means for applying rotation to each of said mounts
thereby to bend the flexible scale model within its elastic limit and
means for controlling said adjustment and rotation in response to
digital input information.

According to a further aspect of the invention, apparatus of analogue
interpolation comprises a leaf spring or other flexible elastic scale
model, a pair of spaced mounts therefor in relation to one or each of
which the scale model is slidable longitudinally, means for effecting
adjustment of the position of said mounts in relation to each other
and of at least one mount in relation to a predetermined co-ordinate
or reference, means for applying rotation to each of said mounts
thereby to bend the flexible scale model within its elastic limit,
means for supplying from a record digital input data corresponding to
the positions of successive datum points along a desired contour or
profile curve and the tangents of said curve at said datum points,
means for controlling said adjustment and rotation of the mounts in
response to the digital input data appertaining to each pair of datum
points in succession, and means for obtaining inter1785,361 polated
information corresponding to each interval between datum points by
following or sensing the flexible scale model between its mounting
points.
When a leaf spring or other flexible elastic scale model is thus
positioned at two mounting points and set at each point at an angle
such that the slope or tangent is equal or proportional to that
obtaining at the corresponding datum point of a desired curved contour
or profile, the flexible scale takes up a third degree or cubic curve
formation, such a curve being the curve of lowest degree compatible
with two position and angle settings as required for continuity
between interpolation curves of adjacent intervals.
The co-ordinates used may be cartesian or polar, and references to " x
" and " y " values should be taken as denoting, in the conventional
manner, a cartesian system In a cartesian application of the
invention, interpolation along a straight portion of a contour or
profile will give rise to aligned equal-angle settings at the two
mounts so that the flexible scale model will assume its neutral state,
which will preferably also be its unstressed condition.
The flexible scale model is capable of representing a portion of a
desired contour with very close approximation, and the accuracy
thereof may be increased by making the scale model large in comparison
with the contour portions it is to represent.
The intervals between datum points may be of equal or unequal lengths
as desired and may be varied in accordance with the complexity of the
contour or profile.
Where checking of an existing article is required, a follower may be
moved along the article in sympathy with a feeler or other sensing
means which explores the flexible scale model and is capable of
providing indications of deviation from the desired contour or profile
The reverse of such arrangement is also possible wherein the sensing

means explores the article.
Certain problems encountered when applying the invention to contour or
profile milling by a machine tool will now be explained in detail with
reference to Figure 1 of the diagrammatic drawings accompanying the
provisional specification.
Considering first the two-dimensional problem of profile cutting, a
rotating cutter wheel or disc C (Figure 1) requires to be guided in
such manner that the cut profile P is generated as specified by
cartesian co-ordinate points x(n), y(n) Thus the centre of the cutter
travels along the curve L which is the locus of points having a
distance R from curve P equal to the cutter radius.
Various methods are available for guiding the cutter, among which are
the following:i The curve L may be calculated from the curve P before
preparing the input information for the interpolator This presupposes
a cutter of known radius.
ii The locus L of the tool centre may be calculated in the machine
control system, This also presupposes a cutter of known radius 70 The
following methods may be used to fit a cubic interpolation curve to
the input data.
1 The curve may be caused to pass through four points y 0-y 3 (Figure
2 of the 75 provisional specification), only the centre section yl-y 2
of the curve being employed.
2 The curve may be caused to pass through only two points, the slope
of the curve being specified at the beginning (j(n)) and at the 80 end
(f'(n + 1)) of each interval in addition to the x, y co-ordinates
(Figure 3 of the provisional specification shows this in relation to
datum points A and B).
The second method has several advantages 85 Firstly, unequal intervals
do not complicate the computation and the generated curve is
continuous in its first derivative This latter consideration is
particularly important in the manufacture of aerodynamic models 90 For
these reasons the input data for the interpolator are specified in
terms of coordinates and slopes at each datum point.
This will be understood more clearly from the embodiments described
hereinafter by 95 way of example with reference to Figures 4, and 7 of
the drawings accompanying the provisional specification and Figure 8
of the accompanying drawing as applied to machine tool control systems
100 A machine tool may be made to operate with various kinds of
co-ordinates, for instance either cartesian or polar co-ordinates
Figure 4 shows a cutting tool C in relation to these two kinds of
co-ordinates and it will be seen 105 that for long thin cross sections
the cartesian representation x, y may have advantages (Figure 4 (a))
whilst for more substantial sections the polar representation R, 9
(Figure 4 (b)) may be profitable 110 Figure 5 shows schematically an

arrangement for the control of a machine tool in two dimensions The
machine tool is fitted with x and y drives together with measuring
systems for both co-ordinates providing indications of 115 machine
tool position through lines 10 and 11.
A subtractor 1 compares the measured position of the table with the
initial value x(n) (cfr.
Fig 3) supplied by a record 7, and unit 1 supplies a difference signal
/Ox to the follower 120 of a flexible strip interpolator system 6 In
addition, subtractor 1 supplies a control signal to a control unit 3
whenever x(n)=x, i e at the beginning of each interpolation interval.
The present description relating to Figure 125 should be read in
conjunction with Figure 3 of the drawings.
The table is driven independently in the x direction.
The input information for a particular 130 system similar to that of
Figure 5, the same reference numerals being employed for corresponding
parts and the x and y drives and machine tool being omitted for
simplicity.
This system employs two flexible scale model 70 interpolators 6 A and
6 B in duplex in order to overcome the time delays involved in
resetting the parameters after each interval Thus one interpolator is
always being sensed for Ay information while the other is being reset
for 75 the next interval, the sensing means chang,;over at the end of
each interval.
A subtractor unit 1 has inserted in it the value x(n) at the
commencement of an interval.
The x co-ordinate measurement from the 80 machine is also fed to the
subtracter 1, preferably from a measuring device according to the
aforesaid Patent Specification No 773,494 (co-pending Application No
14635/53) The output Ax of unit 1 is converted by a digital 85
analogue converter 2 into a shaft rotation for operation of the x
drive in the operative interpolator 6 A or 6 B. The value of y(n) is
inserted into a unit 4, which may be an add/subtract counter, and 90
an analogue-digital converter 5 changes the analogue quantity Ay into
digital form for operation of the unit 4 The number y(n)+ Ay in the
unit 4 is fed to the y co-ordinate measuring and positioning system 95
Changeover fron one interpolator to the other and the insertion of
initial conditions is controlled via gates gl to g S by the control
unit 3 which receives a signal trom the subtractor 1 when
x(n)+Zx=x(n+ 1) 100 The gate g 3 obtains a signal from the
interpolators which is proportional to f(n) and hence supplies a
signal for controlling the speed of the x-co-ordinate drive for
constant speed cutting 105 An example of an interpolator using a
flexible scale model, such as may be used in the systems of Figures 5
and 6, is shown diagramatically in Figure 7 A leaf spring or flexible

elastic strip E is held firmly in a rotat 110 able mount A and has a
sliding fit in a second rotatable mount B The slopes at the ends of
tile interpolation interval A-B are set by gearing 0,, l,, and the
increment Ay(n) is set by a rack and pinion mechanism C A stylus 115
or follower D is driven in the x direction e g.
in sympathy with the cutter on a machine tool.
The stylus follows the strip E and thus measures the distance Ay and
transfers it to the y co-ordinate drive of the machine 120 If
intervals of unequal length are to be used, a second rack and pinion
mechanism may be provided for varying the position of either mount in
the x direction.
With a suitable follower, e g in the form of 125 a wheel, cam or
sector, the instantaneous tool radius may be allowed for when the
displacement Ay is transferred from the follower to the machine tool
control system On the other hand the analogue information available at
the 130 interval A-B (Figure 3) is given from record 7 as parameters
f(n), f'(n + 1), Ay(n) and x(n), together with either Ax(n) or x(n +
1) when successive intervals Ax are not equal.
The interpolation is carried out from A to B by making x(n)=y(n)= 0, i
e by placing the origin of the axes at point A The instantaneous value
Ay is obtained from the flexible scale model interpolator 6 for
varying values of Ax and added to y(n) in a unit 4 to obtain absolute
values of y.
The calculated value y is fed through the line 8 to a differential
unit D and compared with the position of the machine tool in the y
direction The error signal is made to operate the y drive.
A unit 9 employing a signal approximately equal or proportional to the
slope f (n) may be used to control the speed of the x drive so as to
obtain constant-speed cutting, said speed being maintained inversely
proportional to said slope.
The units shown in Figure 5 may take many forms some of which will be
discussed hereinafter.
A measuring system with an accuracy of about 0 0001 inch is required
in many cases, and arrangements as disclosed in Patent Specification
No 773,494 (co-pending
Application No 14635/53) are suitable for this purpose.
The record 7 on which input information is stored may be magnetic
tape, punched tape, or a set of punched cards For general industrial
use punched tape is preferred owing to ease of handling and checking.
Control unit 3, in response to a signal from subtractor 1 when x(n +
1) = x, opens momentarily the four gates which allow the data for the
new interval to pass from record 7 to units 6 and 4 Subsequently
control unit 3 causes the record drive mechanism to advance record 7
so as to present a new set of data to the gates.

Referring again to Figures 3 and 5, the method of interpolation may be
as follows for each interval.
At the beginning of each interval the machine tool is set to x(n) and
y(n) and the output Ay of the interpolator is set to zero.
The independent variable Ax is also set to zero.
As Ax increases so Ay is calculated and added to the value y(n) in the
unit 4 The resultant y(n) + Ay is fed to the differential unit D and
the cutter is set to the instantaneous distance y(n) +Ay When x(n) +
Ax reaches the value x(n + 1) the cycle of operations is repeated for
the next interval i e from x(n + 1) to x(n+ 2), it being understood
that the approximate value of y(n+l) (=y(n)+ Ay(n)) is rejected in
favour of the accurate value of y(n+ 1) supplied by the record so that
errors are not accumulated.
Figure 8 represents in greater detail a 785,361 3 785,361 scale model
surface may, if desired, be converted into a digital output.
If the angles f 1 (n), fl(n+ 1) are set to within minutes of arc and
the displacement Ay(n) is set to an accuracy of 0 001 inch, use of a
scale factor of 10 would permit accuracies of interpolation to 0 0001
inch to be obtained, the scale factor being the ratio between the
length of the portion AB of strip E and the corresponding portion of
the desired contour.
Instead of being rectilinear in its unstressed or neutral condition, e
g as in the arrangement of Figure 7, the flexible scale model may be
part-circular in its unstressed or neutral state.
In one such arrangement for use with polar co-ordinates two mounts are
provided for an arcuate scale model, said mounts being carried by
radius arms converging on a common centre and one at least providing a
sliding connection for the model One arm is pivoted at said centre
while the other arm may be replaced by an equivalent fixed structure
The angular co-ordinate a is set into the device by rocking the
movable arm in relation to the fixed arm and the orientation or slope
of the scale model at each end of the interval is set by partial
rotation of the respective mount in relation to its arm In addition,
the distance between each mount and the centre is adjustable so that
the radial co-ordinates R may be set.
With such an arrangement continuous interpolation and follower action
may be obtained by constructing the scale model as a closed loop or
band supported by three or more mounts carried on radius arms
adjustable both in length (co-ordinate R) and angle (co-ordinate 9)
about a common centre.
All the mounts may be slidable along the scale model, and the latter
may include a free or inoperative bight between the last portion
explored by follower action and a portion that is being set up for the
next interval On the other hand a single follower may be arranged to

follow the scale model continuously in one direction, one or more
arcuate model sections being set up with fresh co-ordinates while any
given section is being explored by the follower.
As will be appreciated, the follower action may be obtained either by
rotating the follower mounting or by rotating the scale model system
in relation to a stationary follower mounting.
The above arcuate arrangements may be modified to operate with
cartesian co-ordinates the arrangement being such that, with suitable
co-ordinate transformations, distances along periphery of the scale
model band represent the x co-ordinates while the adjustable radial
lengths of the arms represent y co-ordinates.
In a further modification of the above arcuate scale model systems, a
flat flexible disc or annular strip is employed in place of the
flexible band, changes of opposite sign in the Y co-ordinate being
represented by deflections of the disc edge in opposite directions
parallel to the axis away from the plane representing its unstressed
or mean condition, and slopes f'(n) and f'(n+ 1) being obtained by
partial rotation of the amounts on radial axes of rotation 70
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* GB785362 (A)
Description: GB785362 (A)
No title available
q:=
T P a: -.
PATENT SPECIFICATION ffling C Gmplete Specificacion June 17, 1955.
ion Date June 21, 1954.

:e Specification Published Oct 30, 1957.
785362 No 18208154.
In d e x at A c c e pta N c e: C l a S S 7 ( 3), D a F 3 r Index at
Acceptance: -Class 75 ( 3), F 3.
International Classification: -F 21 b.
Improvemernts iri or relating to Electric Igniters for Flame Lamps
SPECIF TCATION NO 785,362 IWNVETOR: CECIL D-AVID j AMES ST% THAX BY a
direction given under Section 17 ( 1) Or tte Patents Act 1949 this
application proceeded In the iamre Off Oldhaui & Son Timit 1 ed, a 3
ritisn, company, of 36, Hyde Road, Denton, near i',anrchester,
Lancashire.
THE PATENT OFFICE, 28th October, 1957 _ _ character has been' found to
offer disadvantages insofar as pyrophor ground off by the operation of
the flint mechanism may in certain circumstances lead to the ignition
of firedamp.
It has also been proposed to effect ignition of the vaporising fuel in
a miner's flame lamp by the employment of an electric ignition
filament arranged for connection to a source of electric current
Ignition devices of this character however have not proved entirely
satisfactory in practice as they do not limit the current and
therefore do not obviate the dancer of explosions in an atmosphere of
firedamp and air.
Accordingly, the main object of the present invention is to provide an
ignition device for a miner's flame lamp which will be free from the
disadvantages of the flint mechanism or the electrical ignition
devices previously proposed and which vill provide in use a sufficient
margin of safety to render the lamp and the ignition devic? safe in an
atmosphere of fizedamn and air.
According to the present invention there is provider an elect -c siepi
unit to supply electric current -o an Zlet'fic igniticm filsment
prolPrire is 6 d l D 3 00043/1 ( 10)/3589 100 10/57 R and connected to
said resistance ana wnezziii circuit interrupter means is provided in
said housing to interrupt the circuit con 70 tinuitv to said contact
member or contact element.
In one embodiment of the invention the contact element is fixed in and
extends beyond an insulating bush secured in one end of the 75
housing, the contact member is in electrical contact with the housing,
and the interrupter means comprises a switch operable to make and
break the circuit between the contact member and the conductor
connecting said 80 member to the battery The housing may be
electrically conducting and the contact member gripped between the
bush and housing and disposed relative to the contact element to
permit the contact member and contact ele 85 ment simultaneously to be

applied as appropriate to a fuel receptacle and base, and the switch
may comprise a contact-carrying pillar supported by the housing for
angular movement to and from a position of engagement 90 with a
contact plate The contact element may extend bevond the apex of a
conical insulating bush and the contact member overlie the sloping
surface of the bush The contact-carrving I", __ 5 M'_ 1 I & z 11.
r, PATENT SPECIFICATION
Date of filing Complete Specification June 17, 1955.
Application Date June 21, 1954.
785362 No 18208/54.
Complete Specification Published Oct 30, 1957.
Index at Acceptance: -Class 75 ( 3), F 3.
International Classification: -F 21 b.
Improvements in or relating to Electric Igniters for Flame Lamps We,
OLDEAM & SON LIMITED, a company incorporated under the laws of Great
Britain, of 36, Hyde Road, Denton, near Manchester, Lancashire, and
CYRIL DAVID JAMES STATHAM, a British subject, of 36, Hyde Road,
Denton, near Manchester, Lancashire, do hereby declare the invention,
for which we pray that a patent may he 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 an electric supply unit, for a miner's
electric lamp, to supply electric current to ignite a flame lamp
provided with an ignition filament connected with a pair of external
electric contacts.
It has previously been proposed to effect ignition of the vaporising
fuel in a miner's flamee lamp by means of a flint mechanism.
However, an ignition mechanism of this character has been found to
offer disadvantages insofar as pyrophor ground off by the operation of
the flint mechanism may in certain circumstances lead to the ignition
of firedamp.
It has also been proposed to effect ignition of the vaporising fuel in
a miner's flame lamp by the employment of an electric ignition
filament arranged for connection to a source of electric current
Ignition devices of this character however have not proved entirely
satisfactory in practice as they do not limit the current and
therefore do not obviate the danger of explosions in an atmosphere of
firedamp and air.
Accordingly, the main object of the present invention is to provide an
ignition device for a miner's flame lamp which will be free from the
disadvantages of the flint mechanism or the electrical ignition
devices previously proposed and which will provide in use a sufficient
margin of safety to render the lamp and the ignition devico safe in an

atmosphere of firedamp and air.
According to the present invention there is provided an electric
supply unit to supply electric current to an electric ignition
filament prolPrice ?s 6 d l vided in a flame lamp and having a pair of
external electric contacts connected therewith, said unit comprising a
casing to house the 50 battery of a miner's electric lamp,
electrically conductive elements respectively to be engaged one with
each of said electric contacts and for electrical connection one to
one terminal of the battery in said casing, and the other to 55 one
end of an electrical resistance the other end of which is connected to
the other battery terminal, thereby to restrict the electric curnent
which can pass to the ignition filament to a value substantially less
than the maximum 60 permissible current for intrinsic safety in a
firedamp/air mixture.
The conductive elements may comprise respectively a housing within
which is located a contact member connected with said one 65 battery
terminal and a contact element electrically insulated from said
contact member and connected to said resistance and wherein circuit
interrupter means is provided in said housing to interrupt the circuit
con 70 tinuity to said contact member or contact element.
In one embodiment of the invention the contact element is fixed in and
extends beyond an insulating bush secured in one end of the 75
housing, the contact member is in electrical contact with the housing,
and the interrupter means comprises a switch operable to make and
break the circuit between the contact member and the conductor
connecting said 80 member to the battery The housing may be
electrically conducting and the contact member gripped between the
bush and housing and disposed relative to the contact element to
permit the contact member and contact ele 85 ment simultaneously to be
applied as appropriate to a fuel receptacle and base, and the switch
may comprise a contact-carrying pillar supported by the housing for
angular movement to and from a position of engagement 90 with a
contact plate The contact element may extend beyond the apex of a
conical insulating bush and the contact member overlie the sloping
surface of the bush The contact-carrying 85,362 pillar may be adapted
for angular movement by a key detachable from the unit.
In an alternative embodiment of the invention, the conductive elements
may comprise respectively a housing in which is located a contact
member, and the metal cover of said casing.
In a still further alternative embodiment of the invention the
conductive elements may comprise respectively a housing in which is
located a contact member, and a contact element carried by a cap lamp
connected with said terminals.
In order that the invention may be clearly understood some embodiments

thereof will now be described, by way of example, with rxeference to
the accompanying diagrammatic drawings, in which: Fig 1
diagrammatically illustrates an electrically ignitible flame lamp and
an electric supply unit for use therewith embodying the present
invention.
Fig 2 is a circuit diagram of the electric supply unit, Fig 3 is a top
plan of an element of the supply unit, Fig 4 is a section on line
IV-IV, Fig 3, Fig 5 is a section on line V-V, Fig 3, Fig 6 is an end
view looking in the direction of arrow VI, Fig 4, Fig 7 is a circuit
diagram for an alternative form of electric supply unit, and Fig 8 is
a diagrammatic circuit for a still further alternative form of
electric supply unit.
Referring to Figures 1 to 6 of the drawings, a flame lamp, for example
for use in mines, comprises, in the usual manner, a metal base 1
within which, and electrically insulated therefrom, is a metal fuel
receptacle 2 aranged to contain the oil fuel Substantially on a level
with the wick 3, which extends from the receptacle 2, and adjacent
thereto there is provided a wick ignition device comprising an
electric filament 4 One side of the filament 4 is electrically
connected to the metal vessel 2 which, as stated above is insulated
from the metal base 1, and the other side of the filament is connected
to the metal base 1 The filament is arranged to ignite the wick on the
passage through the filament of an electric current of a value, for
example 0 3 amps, substantially less than the maximum permissible
current for intrinsic safety The base 1 and receptacle 2 accordingly
form a pair of external electric contacts connected with the filament
4 but it will be understood that the flame lamp may be provided with a
pair of insulated contacts mounted on the base and connected with the
filament, or with any other suitable arrangement whereby the filament
is electrically -connected with a pair of external contacts to which
current can be applied by an electric supply unit as described below.
Ignition of the lamp is effected by means of the filament 4 which
derives the requisite current from an electric supply unit which
includes the 4-volt battery 5 of a batteryoperated miner's electric
lamp 6 and a coniact-carrying element 7 The element 7 is illustrated
in greater detail in Figs 3 to 6 70 Referring to Figs 3 to 6, the
element 7 comprises a housing 8 of electrically conductive metal the
housing being hollow and closed at one end by a conical bush 9 of
electrically insulating material and, at the other end, by 75 a brass
gland 10 through which passes a cable 11 carrying conductors shown as
wires 12, 13 by which the element 7 is connected with the battery 5
The wire 12 is connected to a brass terminal stem 14 having a contact
element 15 80 -which extends beyond the end of the bush 9, the wire 12
passing to the terminal stem through a hole formed in an insulating

disc 16 extending across the interior of the housing.
The wire 13 is secured to a contact plate 17 85 wvhiclh is, in turn,
secured by rivets to a block 18 of insulating material, the block
being secured to the interior of the housing by a screw 19.
Mounted in a hollow spigot 20 integral with 90 the body 8 is a
circular electrically conducting key pillar 21 arranged for angular
movement about its axis - vithin the spigot The spigot is closured by
a metal cap 22 and a spring 23 extends between the cap and the key
pillar to 95 retain the pillar in engagement with the bottom of the
interior of the spigot The key pillar is provided with a
contact-carrying portion 24 to wvhich is secured a contact 25 The
outer face of the key pillar is provided with 100 two key-receiving
apertures 26 arranged to receive the prongs of a key 27 whereby the
key pillar may be moved angularly about its axis to be located in one
or other of two positions by detent balls 28 The arrangement of the
ele 105 ment 7 is such that when the contact 25 is in the position
theecof shown in full lines in Fig.
4 the circuit to the battery, is open, whereas when the key pillar is
moved angularly from the position shown in Fig 4, through 1800, to 110
the dotted line position thereof, shown in Fig.
4, the contact 25 engages the contact plate 17 and the circuit to the
battery is then closed.
If, now, it is desired to ignite the lamp, the element 7, with the
contact 25 in the position 115 shown dotted in Fig 4, is placed in
juxtaposition with the iamp, as illustrated in Fig 1, so that the
contact element 15 is engaged with one external contact of the lamp, e
g the metal fuel receptacle 2, and a contact member 29 120 clamped
between the body 8 and the bush 9 is engaged with the other external
contact, e g.
the metal base 1 The contact member 29 overlies the conical surface of
the bush 9 to be so located in relation to the contact ele 125 ment 15
that the element 15 and member 29 can be simultaneously engaged with
the receptacle 2 and base 1 Accordingly the electrical current is
applied from battery terminal A, through wire 13, contact plate 17,
key 130 contact member 29 b is connected with the terminal B of the
battery.
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