Improved Apparatus for Automatically Weighing Quantities of Substances of all kinds.
Year: 1898

page_text: Date of Application, 20th June, 1898-Accepted, 11th Mar., 1899
COMPLETE SPECIFICATION.
Improved Apparatus for Automatically Weighing Quantities of
Substances of all kinds.
I, THEOBALD DOUGLAS, of 6, Sessingstrasse, Berlin, N.W., in the Empire of
Germany, Mine Proprietor, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
The present invention relates to an apparatus for automatically weighing
out substances of all kinds in packets, bags, boxes and the like. The invention
is illustrated in the accompanying drawings, in which,
Figure 1 is a side elevation; and
Figure 2, an end elevation of one form of the apparatus, it being assumed
for example that the apparatus shown is required to weigh corn or pulverised
materials. When required for weighing out liquids, valves are used in place
of the slides shown.
In Figure 2 the details which form no part of the invention or which are self
evident, are omitted.
The scales proper consist of the scale beam A, mounted at aa by central knife
edges in suitable recessed supports; a weighing drum B suspended on knife
edges at a a; and a weight pan C, suspended on knife edges at a² a². A
link (Figure 1) is pivotally connected at one end to the arm 2 of the weighing
drum, and at the other end to the frame 1), in order to secure a parallel move-
ment of the weighing parts. This link and the weight pan C are not shown
in Figure 2.
The frame D carries above the weighing drum a feed hopper E provided with
two closing slides or gates F and G which are hung on the same axis e to control
the feed.
The weighing vessel consists of a drum B divided into compartments, (in the
example shown, three compartments are depicted) which drum is revolubly
mounted on two bent arms 1 and 2 suspended on the knife edges a¹ of the
beam A.
A slide rod flying horizontally upon a projection fixed to the frame D,
which slide is pivotally connected to the inner or first admission slide or gate F,
serves on the one hand to keep the slide or gate F in the open position by a
projection fixed on the slide rod f engaging behind the projection d, and on
the other hand to limit the swing of the scales on the upward movement of the
weight pan at the end of the first part of each filling period. For the purpose
of regulating the balance, a lever H is provided having a slide weight hand
serves for controlling the movement in the case of a rapid feed and a lever J
having a slide weight i is similarly provided to control the movement in the
case of a slow feed.
Two double armed levers K and L are pivoted on the frame D to effect the
simultaneous opening of the feed slides or gates F and G as soon as the drum
for the purpose of discharge is set in rotation, the lower arms of said levers K

page_text: and L which are of unequal lengths being engaged and thus turned by one of
the pins 663 fixed on the drum B, while the upper arms of said levers press
against pins or projections f¹ and g on the feed slides.or gates, and thus transfer
the rotating movement of the drum to the feed slides F and G.
A pendulum N pivotally suspended at within the frame, reaches down
below the drum B into a discharge hopper and the short upper arm. n of said
pendulum always lies obliquely over one of the pins and bon said drum and
is pressed out by the said pins during the rotation of the drum but always falls
back into its normal position.
The mode of action of the weighing scale is as follows:-
The substance to be weighed flows through the feed hopper E into the weigh-
ing drum B and causes the same when filled with a sufficient quantity to sink,
whereupon the shorter lever K slips off the pin 61 and the lever H in consequence
of its counterweight exerts an upward pressure at c against the weighing scale;
by this means the weights in the weight pan may be lightened to correspond
to the overweight produced by a rapid feed or inflow. In cases where it is a
question of weighing off quantities of only small weight, the overweight pro-
duced by a rapid feed or inflow of the substance is so trifling that the lever H
may be dispensed with together with its counterweight h. At the moment in
which the slide rod f by the upward movement of the weight pan C is raised
by the roller c¹ so high that the feed slide or gate F is liberated by the pro-
jection being lifted to slip over the projection d, and closes itself by its own
weight the slide rod f is drawn through the two rollers and by the pull
and coming in contact with owing to its elevated position, brings the scales
to rest before the feed slide or gate has entirely closed. At this moment the
rapid inflow ceases and the pressure of the lever H is checked by said lever
coming to rest on the pin and the substance to be weighed then only flows
through openings f¹ƒ³ provided in the inner gate F in thin streams into the
weighing drum.
After equilibrium has been attained, the weighing drum sinks once more,
whereby the longer compound lever L is disengaged from one of the pins 61 62
and 63, in order to allow of the closing of the second admission slide or gate G
which takes place by reason of the weight alone of said gate G causing it to
close when not prevented by said lever L.
The filled compartment of the drum is mounted over its axis with a bias to
the left, by which means the drum makes a partial revolution after it has
become disengaged from the lever L and the contents of the compartment are
thus emptied.
In order to prevent the substance from being fully discharged from said com-
partment before the completion of the rotation of the drum. necessary for
bringing forward a fresh compartment under the feed hopper which would
prevent the feed slide or gate opening properly, the following arrangement is
adopted:
Besides the drum, a curved and adjustable surface M is arranged against
which the outflowing substance strikes whereby said substance is caused to exert
on the partition of the drum compartment a pressure which can be regulated
and which causes the drum to turn sufficiently to bring said partition to the
perpendicular. The drum is thus forced to completely carry out the part move-
ment which it has at times to perform.
As long as the lever K under the weight of the heavy feed slide or gate G
presses with its lower arm against the pin b¹, it tends to force the drum back
to the right, and for this reason a stop lever is pivotally mounted on the
arm to prevent the drum from running back by engaging with its hooked end
over one of the pins 64 75 76 fixed on the drum.
A second stop lever is also provided in the form of an elbow lever 69 pivotally
mounted on the arm and having on its lower arm a catch or tooth directed in
an opposite direction, which prevents the rotation of the drum to the left so

page_text: that thus the drum is held quite firm during the filling period with the material
to be weighed.
The catch lever 69 carries on its upper end a pivoted piece 68 which when laid
over to the right, as shown in Figure 1, receives a little push from the gate F
or rather the projection or pin fi of said gate when the latter drops back to stop
off the feed at the end of the first part of the filling period. In consequence of
this push the stop lever 69 is slightly turned and thereby releases the pin b
so that the filled drum in consequence of its overweight can now rotate unim-
pededly to the left, as soon also as the lever L slips off the pin b¹ and thereby.
entirely releases the drum.
For exactly regulating the filling or weighing, the lever J having a slide
weight is used. When for example the filling or weighing is found to be too
light or under weight, the slide weight is pushed correspondingly towards
the right, until after repeated trial fillings, the counterpins are found to
register exactly with one another, and (conversely) weight i is pushed to the
left if the weighings are found too heavy or over weight. In order to render
this control possible, the weighing drum must be prevented from emptying;
for this purpose the hook 68 is turned to the left so that it is not encountered
by the falling back gate F and the catch lever 69 is therefore not released but
holds the drum fast, and the lever J is lifted with the left hand, in order
thereby to give the scales free play.
When the weighings are found to be correct, the scales are again set in action
by again turning round the hook 68 towards the right and for the first weighing
the catch lever 69 is released by hand.
On the piling up of the material in the discharge hopper O, the pendulum N
prevents the emptying of the weighing drum in order that the scales may not
be deprived of their free movement during the next filling, and incorrect weigh-
ings, as well as interruptions in the course of working are avoided. The pen-
dulum acts in such a manner that when the discharge hopper O is full, the
substance therein will weight the lower end of the pendulum and cause the
arm n to hold the drum fast by the pin b5 until the discharge hopper is again
empty, and the pendulum thereby released; the latter now easily yields to the
bias of the drum.
A counting apparatus can be attached in order to control the quantities
weighed, which can be set in action by a suitable part of the apparatus for
example by the slide or rod f.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. An automatic weighing apparatus having a weighing drum divided into
several compartments for weighing substances of all kinds, characterised by the
feed slides or valves, being opened by one of a number of pins (61 62 6³) fixed
on the weighing drum (B) engaging double-armed levers (K and L) which are
pivotted on the frame when said drum rotates to empty one compartment and
bring another compartment under the feed hopper, substantially as hereinbefore
described.
2. In an automatic weighing apparatus such as described, the arrangement
for ensuring a complete emptying of the drum consisting of a curved surface (M)
which may be adjusted towards the axis of the drum and which is adapted to
cause the substances in the act of being discharged to press upon the partition
of the compartment, with a pressure which may be adjusted, substantially as
hereinbefore described.
3. In an automatic weighing apparatus such as described, the arrangement of
a slide (f) for bringing the first feed slide or valve (F) to a standstill and for
limiting the swing of the scale beam at the end of the first filling period by
bearing against a fixed roller (2) for the purpose of bringing the scales quickly
to a standstill substantially as hereinbefore described.

page_text: 4. In an automatic weighing apparatus such as described, the arrangement
of a pendulum (N) adapted to be held down by the substances being discharged
in the event of the latter piling up in the discharge hopper and to prevent
rotation of the drum in such case by means of a suitably arranged finger (n) on
its upper end and thereby stop the emptying of the filled compartment, until
the obstruction to the discharge has been removed, substantially as hereinbefore
described.
D
1011. 1 T 1000
WM. P. THOMPSON & CO.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.