This document describes improvements to a benchtop weighing apparatus. It consists of three key elements: 1) A multi-scale dial face with multiple pointers of different lengths that indicate weight across concentric circular scales, addressing trigonometric issues of traditional single-scale designs. 2) An adjustable levelling device and locking mechanism for transport that prevents wear using external controls. 3) An optional auxiliary weight that increases capacity without needing to change knife edges, aided by a visual indicator of increased scale units. Detailed drawings and descriptions are provided to illustrate these elements and variations in implementation.

1. * GB780184 (A)
Description: GB780184 (A) ? 1957-07-31
Improvements in or relating to weighing apparatus
Description of GB780184 (A)
COMPLETE SPECIFICATIGN
Improvements in or relating to Weighing Apparatus
I, CARLO CURIONI, of Viale Varese 11, Como, Italy, of Italian
nationality, 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 state
ment:-
This invention relates to weighing apparatus of the kind having a
pendular counterweight resistant and in which the weight is indicated
on a scale, without the use of tapes or other flexible means, has has
for its main object to provide an improved weighing apparatus of this
kind for bench service, which is easy and cheap to manufacture and is
efficient and accurate working.
The invention accordingly consists in a weighing apparatus of the kind
referred to, having a pendular counterweight resistant, and comprising
an adjustable levelling device and an externally operable locking
device for the moving parts in order to prevent wear during transport,
the reading of the weight indication being effected on multiple scales
formed as concentric sectors of circles of various radii, on which the
weight is indicated by a plurality of hands rigidly connected to each
other, and of differing lengths corresponding to the radii of said
scales.
The invention will be more completely understood from the following
detailed description which is given in conjunction with the
accompanying drawings, in which :
Figure 1 shows a dial-plate of known type;
Figure 2 shows a dial-plate of the weighing apparatus according to the
invention;
Figure 3 shows a vertical section of a weighing apparatus embodying
some of the features of the invention

2. Figures 4 and 5 show details of the knife supporting blocks for the
weighing apparatus of Figure 3; whilst
Figures 4a and 5a are side views in section of the supporting blocks
of Figures 4 and 5 respectively;
Figure 6 shows on an enlarged scale in respect to Figure 1 and in
elevation the indicator hand mechanism and a form of the braking
device;
Figure 7 represents another braking device of the indicator hand in
vertical view;
Figure 8 is a schematic frontal view of the weighing apparatus lying
on an inclined plane and disposed at the level, and comprising the
device according to this invention;
Figure 9 is a vertical section of the weighing apparatus according to
the invention, and comprising besides the levelling device also an
auxiliary weight for the compensation of any disturbances of
equilibrium of the counter weight;
Figure 10 is a front view of the weighing apparatus as per Figure 9 in
which only the levelling device is shown in a plane at 90" with
respect to that of Figure 9.
Now, referring to Figures 1 to 4, it is assumed by way of example that
the capacity of the weighing apparatus is 3 kg., it being understood
that the capacity, as well as the size, the form and shape, and the
number of dial-plates and hands may be varied at will.
The goods to be weighed are placed on a scale pan 1 supported by
knife-edge 2 of a lever 3 fulcrummed at 4 by means of special
articulated supporting blocks 5 shown more in detail in Figure 4, the
lateral stability of the scale plan being secured by an extension 6
and an arm 7.
The long arm 31 of lever 3 carries a knife edge 8 on which rests
through a special double cardan bearing 9, shown more clearly in
Figure 5, a hulls shaft 10, the upper end of which bears on a
lonife-edge 11 of a pendular counterweight resistant comprising a
lever 12 which is fuicrummed at 13, and which carries a counterweight
14. The lever 12 also carries a rack 15 engaging a pinion 16 of the
shaft carrying the indicator hand, such shaft being supported by two
ball bearings. A damping device 23, which is situated in the lower
part of the apparatus and works by means of air and a liquid,
completes the weighing apparatus.
The weight indicating dial is arranged, not as per the known system
shown in Figure 1, with a circular single graduated scale served by a
single hand 18, but according to the system shown in Figure 2, in
which three graduated scales 20, 201, 2011 are employed and
constructed in the form of sectors of circles of different radii, and
the weight is indicated by three pointers 19, 19', 19" of successively

3. increasing length, hand 191 being the longest.
The angle between pointers l9 l and 191 and the angle between pointers
191 and 19 are both about 116 , so that the angle between pointers 19
and 19ill is about 128'. If preferred, however, other angles may be
adopted, and the number of pointers may be varied, e.g. there may be
two, four or five. The purpose of the larger angle between pointers 19
and 19'1 is to hide the pointer 19 from the initial visible field.
Scale 20"= which is of longest radius, serves for pointer 1911 which
indicates weights from 0 to 1 kg., at which position pointer 191 takes
over to indicate weights on the scale 201 from 1 kg., to 2 kg.,
followed by pointer 19 which indicates on scale 20, weights between 2
and 3 kg., pointer 19 being the shortest, and adapted to co-operate
with the scale 20 of smallest radius, so presenting the limit of the
Weighing apparatus capacity.
This system frees the manufacturer from the trigonometric difficulties
normally met with, because a separate graduated scale is provided for
each one of a plurality of pointers, so that it is possible to make
the scale divisions with different spacing in accordance with the
rotating angle resulting from the instrument, so that each scale can
be calibrated individually.
Furthermore, the weighing apparatus may be provided with a device to
increase its capacity such device comprising a cranked handle 25
(Figure 3) which by means of shaft 26 and eccentric 27 actuates the
lever 28 to lower or raise with its end 281 a conically shaped weight
29 positioned so as to rest in an appropriate seat 30 fixed on arm 31
of lever 3. The weight 29 has a movable part 31, which may be
displaced upwards, to compensate for the varia- tion of the centre of
gravity of the instrument when weight 29 comes into operation, so
facilitating the control of the weighiilg apparatus, without having to
undertake the difficult operation of changing the knife edges 2 and 4.
One or more of such weights may be used, and an indication of the
increased capacity of the scale may be provided according to one of
the already known methods, as for instance in this case by means of a
rod 32 which rotates a dial 21 situated at the back of the dial 22, so
as to change the number of the scale unit visible through windows 36
in said dial 22.
The bearing represented in Figures 4a and 4 consists of an upper part
5 serving as a bearing in its proper sense, and a lower part formed by
a portion of a sphere 33 (more than half sphere) with a base 34 shaped
as shown in
Figures 4 and 4a. The lower part 33-34 is enclosed within a cup-shaped
bearing 35, thus permitting a quick ; setting up of the instru- ment,
without the necessity of any adjustment operation because the
knife-edge bearing (5.33 -34) assumes its correct position by itself

4. in any direction.
The double cardan bearing represented in
Figures 5 and 5a constitutes a cardan coupling obtained by means of
knife edges and bearings for the weighing apparatus. In the same
figures it is shown that the bottom of the two channels 37 and 36 are
at the same level. By means of this arrangement the knife edge 8 can
still operate accurately when the head of the weighing apparatus is
disposed at 90" with respect to the position 24 shown in Figure 3, the
shaft 10 being constructed in two tubular parts to permit this
disposition.
In Figure 6, hand 19 and a toothed pinion 16 which rotate around the
same pivot are shown, this pinion engaging rack 15. Rack 15 rests
lightly against pinion 16 and cannot disengage, being pressed by the
small roller 38.
The locking system is controlled by a small outwardly projecting knob
39 which is rigidly connected to shaft 40. By pulling out knob 39 and
rotating it through 90;, the pin 41 presses against a member 42,
causing the knob 39 to remain in its outer position. Shaft 40 carries
a plate 43, the projecting part 44 of which is bent at right angles.
In the locking position of knob 39 the part 44 bears against the rack
15, urging it in the direction of the arrow 45, that is against pinion
16, so as to prevent any movement of these parts, and therefore any
wear, springs 46q6'contributing to the regular operating of the whole
locking device.
In the alternative locking arrangement shown in Fig. 7 the roller 38
is carried on one arm of an elbow lever 47 pivoted at 48, the other
arm 471 of which has its end free and shaped in the form of a
dead-eye. The latter is slidably arranged on the shaft 49 and held in
place by means of a nut 50 which opposes the action of the regulating
spring 51. When the apparatus is locked, for instance by means of the
external cranked handle, the small stay bolt 52 is lowered and the
spring 53, being more resistant than spring 51, lowers the arm 471 of
lever 47 so that roller 38 may press against rack 15 in the direction
of the arrow 451, operating thus the reauired locking.
The levelling device as seen in Figures 9 and 10, comprises a
spherical joint, provided with a locking device.
On the recessed part 54' of the bottom 54 of the weighing apparatus,
there is a screw 55 which holds a sphere 56 on to which the locking
stirrup 57 has been engaged, such stirrup being of circular form and
carrying two flanged projections. Only one, 58, is shown.
One projection is secured to the base 59 by pin 60, whilst the other
projection 58 has an inclined plane on which rests the screw 61
provided with the joined cranked handle 62 at one end and with a
conical pin 63 at the other end.

5. Thus, by unscrewing the cranked handle 62, the sphere 56 and with it
the weighing apparatus may be released so that the scale pan 64 of the
weighing apparatus can be adjusted to a horizontal position, if the
supporting sur- face 65, on which the base 59 rests, is not level (see
Figure 8).
A further improvement of the weighing apparatus forming the object of
this invention consists in the association with the counterweight 14,
which is shown in Figure 3, of a second auxiliary counterweight 66
(Figure 9) which moves in synchronism with the first and has a
compensating function, thus bringing about a greater stability of the
weight-indicating hand, particularly in cases where the weighing
apparatus is not level. In this case the locking device comprises a
single cam 71 which effects by suitable means the temporary locking of
both masses 14 and 66 and of rack 15 with its pinion 16.
All the schematic functional part of the other parts of the scale is
similar to that already described and illustrated in Figures 2 to 8.
More precisely in its constructive form, given as an example in Figure
9, the auxiliary weight 66 is fixed to an arm 67 fulcrummed at 68,
which receives the load by means of the rod 69 resting on arm 70 which
drives also the weight 14 by means of rod 10.
The pendular counterweights 14 and 66 and the rack 15 can be locked by
operating cam 71 which actuates rods 72 and 73 and arms 74 and 75.
Thus by displacing the cam 71 and consequently rods 72 and 73 and arms
74 and 75 it is possible to raise the supports 76 and 761
respectively, to move upwardly the outer ends of arms carrying the
pendular counterweights 14 and 66 so as to lock the said arms and
their counterweights against the projections 77 and 78 respectively of
the cylindrical head 79.
In order to lock rack 15 and pinion 16, a stop 80, which is firmly
connected to the connecting device 73, produces the necessary pressure
on the back of the rack 15 so as to constrain the latter against the
pinion 16, thus pre- venting any movement.
What I claim is : -
1. Weighing apparatus of the kind referred to; having a pendular
counterweight resistant, and comprising an adjustable levelling device
and an externaly operable locking device for the moving parts in order
to prevent wear during transport, the reading of the weight indication
being effected on multiple scales formed as concentric sectors of
circles of various radii, on which the weight is indicated by a
plurality of hands rigidly connected to each other, and of differing
lengths corresponding to the radii of said scales.
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