Improvements in or relating to Weighing Machines.
Year: 1893

page_text: Date of Application, 31st Oct., 1893-Accepted, 13th Jan., 1894
Improvements in or relating to Weighing Machines.
A communication from JOHN R. GRABILL and PHARES R. GRABILL, Millers, of
Millersburgh, Dauphin County, State of Pennsylvania, United States of
America.
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of the said invention, and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates to improvements in automatic weighing scales adapted
particularly for measuring by weight grain, tea, coffee, rice and similar substances
which will flow into and from a receptacle, the object of the invention being to
simplify and improve the mechanical construction, whereby greater accuracy and
rapidity of operation are secured.
The invention consists in certain novel details of construction and combinations
and arrangements of parts all as will be now described and pointed out particularly
in the appended.claims.
Referring to the accompanying drawings:
Figure 1 is a side elevation of a scale constructed in accordance with this invention
with portions of the standard broken away to show underlying parts.
Figure 2 is a detail of the cut off and connected parts.
Figure 3 is an elevation showing the lock for the rotary measuring vessel.
Figure 4 is a diagrammatic view showing the preferred means for tailing off or
reducing the rate of supply as the measure becomes filled.
Figure 5 is a perspective view of the improved scales with portions broken away..
Figure 6 is a plan view of the same.
Figure 7 is a side elevation thereof.
Figure 8 is a plan view showing a modification.
Figure 9 is a front elevation of a pair of counter scales embodying the present
invention.
Figure 10 is a rear elevation.
Figure 10 is a detail perspective of the catch shown in Figure 6.
Figures 11 and 12 illustrate the preferred form of catch or lock, and
Figures 13 to 16 are modifications of the gravitating contact maker.
Like letters of reference in the several figures indicate the same parts.
In the first form of scale illustrated in Figures 1 to 4, a rotary measuring
vessel A is pivotally mounted on standards a secured on the platform A² of an
ordinary platform scale B, having the usual beam B and connections B5 between
the platform and beam, the construction of the measuring vessel being such that
when the upper compartment is filled, the weight of the material will be sufficient
to rotate the vessel bringing the other end uppermost when .released as will
presently appear.
Beneath the measuring vessel and supported from the base in any suitable manner
as by rigid supports C carried by the standards D', is a chute C into which the
grain is dumped, while above the vessel is mounted a hopper D, preferably carried
by a spider & adjustably secured at the corners to standards D' extending up from.
the base.
In the bottom of the hopper an opening or openings e are formed with a pivoted
spring pressed cut-off E for closing the same, to arrest the feed of grain to the
measuring vessel. This cut off is closed by the central coil spring E shown in

page_text: dotted lines Figure 2, to cut off the grain when the proper quantity has passed into
the vessel and by its movement the vessel is released and allowed to discharge the
grain thus the possibility of the vessel turning while the grain is still being fed is
avoided. To accomplish this the vessel is provided on one side with locking
projections formed as shown by the projection c and spring tongue e¹ Figure 2 and
a lock or catch E¹ Figure 3, mounted on a fixed member E is adapted to engage
therewith. The catch E' is moved by the cut off to release the vessel through the
medium of the arm E on the cut-off (Figures 2 and 3) having a slot €² in the end
through which the upper end of the catch E' projects.
In operation when the cut off closes it moves the catch or lever back as shown
in dotted lines, Figure 3, releasing the vessel, when the weight of the grain turns
the same bringing the other end uppermost where it is automatically caught and
held by the catch co-operating with the projection c at the opposite end of the
vessel.
The cut off is returned to open position against the tension of spring E by a
lever F pivoted to the vessel supports preferably below and to one side of the
vessel pivots and in position for its upper end to engage the projecting end of the
cut-off. A projection or lug f¹ on the side of the lever is adapted to be struck by
one or the other of a pair of lugs or projections f3 on the side of the vessel. The
pivots of the vessel and lever and the lugs are so positioned relative to each other,
that as the vessel rotates the uppermost lug on the vessel engaging the lug on the
lever moves the lever over until the vessel just reaches upright or normal position,
when the lugs pass owing to the eccentric relative position of the pivots of the
lever and vessel and the lever under the influence of its weight f³ returns to
normal position.
The lever F in its forward movement carries the cut off to open position against
the tension of its spring (the latter as before mentioned being held in the box at the
center of the cut-off) where the cut off is caught and held until released by the
depression of the platform due to the weight of grain discharged into the vessel.
The major portion of the present invention relates to the mechanism for releasing
the cut-off to stop the feed of grain to the movable vessel for it is obvious that
unless this be done at just the right instant and without imposing any appreciable
work or weight on the beam or platform, accuracy cannot be secured. This has
been heretofore one of the chief difficulties encountered in this class of scale.
To secure great accuracy and nicety of action we employ an electro magnet to
release the catch for the cut off and energize the magnet by means of a circuit made
or broken through the medium of a contact set in motion by the movement of the
platform or beam.
In the preferred construction the magnet G is mounted on the base of the
hopper just above the path traversed by the end f of the cut-off and the catch is
connected to the armature g of the magnet. The catch shown in Figures 7 and 8
is preferred, and consists essentially of a catch lever H jointed to the armature
and having a projection on the under side behind which the cut off arm f is held.
The end of the catch lever is pivoted in the support as at 1 in Figure 11 or
allowed to rest on the top of the arm as in Figure 13 if desired, in the latter
instance, however the connection between the lever and armature must be a hinge
connection so as to hold the lever in position.
In both forms the catch lever permits the arm f to return to normal position
and automatically engages it as in an ordinary spring or gravitating catch.
The circuit wires pass from the magnet to a battery located in a box on the
standard or upright of the scale, thence to a point in proximity to the beam where
one terminates in contact with the yoke or pivot support I for the tube K forming
the gravitating contact.
The tube K is preferably exhausted and contains a globule of mercury with
contact points in electrical connection with the circuit wires and arranged to be
connected by the mercury when the tube is inclined one way, and to be disconnected
when the tube is inclined the other way.

page_text: The pivots of the tube are so located that the mercury normally gravitates to
the rear end leaving the circuit broken, but requiring but the slightest possible
power to incline or tilt it in the other direction sufficiently to cause the mercury to
run down and establish the circuit. The most handy way of tilting the tube is to
secure a finger L to the base of the beam, which finger striking the under side of
the tube as the beam rises, inclines it enough to let the mercury gravitate to the
opposite end thereby cutting off the supply of grain to the vessel."
Instead of pivoting the tube on an independent support it is obvious that it may
be mounted directly on the beam as shown in Figure 13 which arrangement is
preferable because the beam may be then balanced with absolute accuracy. So
too instead of a globule of mercury a ball of carbon or similar conductor may be
employed as shown, for instance in Figures 15 and 16, wherein it will be seen that
the terminals i are located side by side in the end of a tube which may be of
metal lined with an insulator and the carbon ball gravitates from one end to the
other of the tube in a manner similar to the globule of mercury before described.
The terminals in this instance should also be carbon concaved to fit the ball whereby
a perfect contact is assured.
The gravitating contact it will be seen enables me to secure a firm and sure
contact without imposing any additional weight on the beam or platform, such as
would be the case if simple contacts were employed as heretofore.
To secure the gravitating action it is obvious many devices may be employed in
which the beam or platform moves the gravitating member up to the center while
the contact is made instantly and always when the beam has been elevated exactly
the same distance by the falling of such member upon a co-operating terminal
contact, for instance in Figure 10 an overweighted tongue M is seated on a terminal
at the bottom of a conical cup M', one side of which is insulating while the opposite
side holds a contact in position to be struck by the end of the gravitating tongue
when the cup is inclined toward that side.
In the second form of the invention Figures 5, 6, 7 and 8, the hopper feed
slide E Figs. 5, 6 and 8.is centrally pivoted at one end, at f³, to the underside of
the bottom of the hopper, and having the usual feed openings adapted to register
with corresponding openings in said hopper bottom.
The slide is closed or moved to cut off the grain by a flat spring g', preferably
mounted on the hopper bottom as shown in Figure 6 and at one side the slide is
provided with an actuating lever f, the arms of which project in opposite directions
and serve to lock the movable vessel and reset and hold the slide as will presently
appear.
The slide E also has connected to it a second lever F having a lateral lug h*
adapted to strike or co-operate with the upper end of the upright lever G₁ having,
near its lower end, a bend or crook g₁ adapted normally to lie in the path of the
stud or studs f on the side of the vessel when the latter is in position to be filled.
The lever F moves said lever G out and releases the stud as the slide closes
thereby allowing the vessel to rotate and dump the grain.
Secured to one of the standards a is an outwardly bowed or bent spring I*
engaging the lever G₁ to press it back in position to engage the stud f² when the
slide is again opened.
The armature lever g is pivoted to one side of the standard of the platform
scales, and has one end upturned and adapted to stand in the plane of movement of
the feed slide lever f, the upper end of the lever being inclined or beveled to permit
the passage of the feed slide actuating lever upon its return movement. The
opposite end of said lever g has connected to it a spring also connected to
standard to automatically hold the upper end of said lever in the plane of movement
of the feed slide actuating lever, as just stated.
Suitably supported by bracket or otherwise, upon one side of the standard is an
electrical generator or battery, and upon the inner side of said standard is the
electro magnet G adapted to engage or attract the lever g and arranged in electrical

page_text: connection with said battery. The wires leading from the battery extend along
he side of the scale beam and terminate in contacts or electrodes secured to the
under side of said support, which being of wood insulates them from each other.
The scale beam B has secured to or cast with it a metallic branch or bifurcated
circuit maker and breaker N* its arm or branch being adapted to engage the contacts
or electrodes and move them into contact with each other.
In operation, the measuring vessel or dump when filled with grain or other sub-
stance fed from the hopper, will through transmission of the weight of its contents
by means of the standards supporting said vessel or dump, to the platform, depress
the latter, causing the kicking of the scale beam.
The upward movement or "kicking" of the scale beam will effect engagement
of the circuit maker and breaker, with the electrodes on the scale beam support, and
establish or close the circuit causing the maguet to attract the armature lever thus
removing the latter out of the plane of movement of the feed slide lever and
allowing said feed slide lever sufficient movement, under the action of its spring, to
effect the closing of the feed opening in the hopper bottom, and thereby cut off the
feeding of the grain or contents of the hopper to the measuring vessel or dump.
The lever F, having the lug h thereon acting upon the lever G' moves the latter
outward compressing the spring I, and thus disengages the crook g*, from the
stud of the vessel or dump and permitting it to discharge its contents into the
chute G for final disposition.
The weight having thus been removed from the platform and the scale beam
consequently returned to its former position the circuit is broken and the armature
lever released and returned to position to engage the cut-off lever. The vessel or
dump makes a semi-rotation and the upper stud 6 thereon engages one arm of the
feed-slide lever, and resets the feed slide thus opening the feed orifice of the hopper
to the other chamber of said vessel.
Simultaneously with the resetting of the feed slide of the hopper by the upper
end stud of the measuring vessel, the crook or bend of the lever G will under the
action of its spring automatically snap into engagement with the stud on the
measuring vessel or dump, to hold the dump in place, and the feed slide lever
having been brought around to its original position by the action of the resetting
stud, it will snap past the bevelled end of the armature lever and thus be held,
against the action of the spring g', until the filling of the other chamber of the
measuring vessel takes place and the kicking of the scale, again closing.
establishing the circuit when the operations before described are again gone
through with.
.or
In Figure 8 is illustrated a modified form of magnetically operated catch for
holding the feed slide with the apertures open. It consists of a permanent magneti
of sufficient strength to hold the arm f, when moved into contact therewith as
shown in full lines, the position of the slide and lever then being in position for
the grain to feed. Surrounding the permanent magnet is a coil or helix wound
reversely or traversed by the current in such direction as to reduce or neutralize
the power of the magnet, hence when the circuit is established by the kicking of
the scale beam the power of the magnet is instantly neutralized and the lever released
permitting the slide to close under the influence of its spring.
In Figures 9 and 10 is shown an ordinary grocers or counter scales adapted
to weigh grain etc., automatically. P indicates the scale frame P¹ the balance
beam and P the scoop, which latter is pivoted on trunnions p at each side and
located with such relation to the scoop and its center of gravity that when the
scoop is empty it gravitates to upright or normal position (see Figure 9) and
when filled the weight of the grain or other substance tends to turn it to inclined
position as shown in dotted lines in said figure.
Above the scoop is arranged a supply hopper having a pivoted cut-off similar
to that heretofore described and operated by an arm n³ secured rigidly to the side
of the scoop.

page_text: To retain the scoop in upright position it is provided with a catch pin or projection q
which co-operates with a lateral projection 93, Figures 10 and 10 on the spring
pressed catch lever Q mounted on an arm Q₁ of the standard Q' carrying the
hopper.
An electro magnet R co-operates with an armature R¹ on the lever Q to release the
catch projection at the proper moment. The circuit controlling the magnet is
established by a gravitating contact such as before described operated by the beam.
This contact is preferably located in the central standard as shown at S and the
circuit wires pass through the base and up to the magnet as shown in dotted lines.
From the foregoing the operation will be readily understood thus in the grain
scales, assuming that the cut-off is open the grain or other substance flows from
the hopper into the upper compartment of the measuring vessel until the beam
moves up indicating that the vessel has received the quantity of grain desired.
In its upward movement the beam moves the gravitating contact K and establishes the
circuit through electro magnet G which in turn instantly releases the cut off lever
and under the action of its spring the cut off closes the opening from the hopper
and through the arm and link E2 Figure 2 releases the catch or lock E' permitting
the vessel to turn half way over dumping the grain in the compartment at one end
and bringing the compartment at the other end up into position to receive grain
from the hopper. To again open the cut-off, as the vessel nears the end of its
movement one of the lugs f2 on its side strikes the lug on the lever F moving
the latter and causing it to engage the end of the cut-off lever opening the cut
off and moving the lever f back beneath the catch g when the parts are in their
original position and the operations just described are again gone through with,
until the whole quantity of grain is measured.
With the grocers scales the operation is the same, save that the measuring vessel
does not rotate but simply oscillates and the lever arm p² (before described) on its
side is employed to operate the cut-off instead of the lever F as in the other
instances.
With scales constructed in accordance with this invention grain and similar
substance may be measured with almost absolute accuracy and with any of the
ordinary well known tallying mechanisms a perfect record may be kept the
measuring and tallying operations being carried on automatically from beginning
to end.
It is entirely practical to locate the counter or tallying device at a distant
point and operate the same through the medium of an electric circuit for releasing
and measuring vessel.
In Figure 9, a counter U is shown in this circuit and may be located at a distant
point, as for instance, in the office of an elevator or mill, while the scale itself is
located in any suitable place.
While an electrically operating tallying device has been shown and described it
is obvious that any of the ordinary well known mechanism of this character may
be employed whether operated electrically or mechanically by the tilting of the
measuring vessel, the only essential being that no additional weight or resistance be
offered to the movement of the scale beam.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondents, and in what manner
the same is to be performed, I declare that what I claim is :-
1. In a scales, such as described, the combination with the movable measuring
vessel having a locking stud or projection and the lever co-operating therewith to
lock the vessel, of the spring pressed feed slide, a lever connected therewith
co-operating with the locking lever to release the vessel and a catch for holding
the feed slide, operated by the movement of the scales; substantially as
described.
2. In a scales, such as described, the combination with the movable measuring
vessel having a locking stud or projection and the lever co-operating therewith to

page_text: lock the vessel,. of the spring pressed feed slide, a lever connected therewith
co-operating with the locking lever to release the vessel and an electro-magnetically
catch having its circuit controlled by the movement of the scales for holding the
feed slide in set position; substantially as described.
3. In a scales, such as described, the combination with the movable vessel and
spring pressed feed slide, of a lock for the vessel actuated by the feed slide and a
resetting lever for the feed slide actuated by the vessel with means for releasing
the feed slide actuated by the movement of the scales; substantially as described.
4. In a scales for automatically weighing grain, the combination with the movable
measuring vessel and lock for holding the vessel in position, of the hopper, the
feed slide closed by spring pressure and controlling the lock for the measuring
vessel, the electro magnet, electric circuit including said magnet and contact for
establishing said circuit controlled by the scales, whereby the feed slide is released,
and in turn releases the measuring vessel; substantially as described.
5. In an automatic weighing scale, the combination with the movable measuring
vessel, and lock therefor, of the hopper, the feed slide closed by spring pressure
and controlling the lock for the vessel, the electro magnet energized by a circuit
controlled by the scales to release said slide, and the lever actuated by the
measuring vessel and co-operating with the feed slide to open the same as the vessel
reaches normal position; substantially as described.
6. In a scales for automatically weighing grain, the combination with the tilting
measuring vessel having a resetting stud thereon, of the hopper, the spring pressed
slide for cutting off the flow of grain, the arms or lever projecting from said slide,
actuated by the resetting stud on the vessel to reset the slide and an electro
magnetically controlled catch for holding the feed slide in set position with contacts
controlled by the movement of the scale interposed in the magnet circuit ;
substantially as described.
7. In an automatic weighing scales, the combination with the releasing mechanism
for automatically discharging the substance being weighed and an electro magnet
controlling said releasing mechanism, of an electric circuit including said magnet
and a gravitating contact maker in said circuit tripped by the scale and allowed to
continue its movement independently, whereby the circuit is established without
perceptibly weighting the scale beam; substantially as described.
8. In an automatic weighing scales, the combination with the releasing mechanism,
whereby the substance being weighed is automatically discharged and an electro
magnet controlling said releasing mechanism, of an electric circuit including said
magnet, a contact maker in said circuit having a gravitating member, the movement
of which is initiated by the scale and completed by gravity to establish the circuit
and release the substance being weighed.
9. In an automatic weighing scales, the combination with the pivoted measuring
vessel, the platform carrying the supports for said vessel, the scale beam, the hopper
and the cut-off for the hopper, of the catch controlling the movement of the vessel
moved by the cut-off, the electro magnet controlling said cut off the gravitating
contact maker moved by the scale beam and the electric circuit including said
contact maker and magnet; substantially as described.
10. In an automatic scale, the combination with the automatic weighing
mechanism, the hopper and the cut-off controlling the passage of grain from the
hopper, of the two electro magnets successively controlling said cut-off electric
circuits including said magnets and contacts included in said circuits and moved by
the scales to establish the circuits successively as the weight increases, whereby the
flow of grain from the hopper may be reduced and finally cut off entirely ;
substantially as described.
11. In an automatic scale, the combination with the automatic weighing
mechanism, the hopper and the spring pressed cut-off controlling the passage of
grain from the hopper to the scales, of the two electro magnets successively con-
trolling the cut off, electric circuits including said magnets, contacts in said circuits
operating to close the circuits successively and moved by the scale beam, whereby

page_text: one circuit and magnet is energized to partially close the cut-off then the other
circuit and magnet is energized to completely close said cut off as the weight on the
scales increases; substantially as described.
12. In an automatic weighing scales, the combination with the automatic
weighing mechanism, the hopper and cut off therefor, of the electro magnetically
operated catch for said cut off consisting of the pivoted member having the
armature thereon and the member jointed to said first mentioned member and having
a shoulder for engaging the cut-off'; substantially as described.
Dated this 20th day of October 1893
W. P. THOMPSON & BOULT,
Agents for the Applicant.