Improvements in Weighing-apparatus.
Year: 1895

page_text: Date of Application, 23rd Jan., 1895-Accepted, 14th Dec., 1895
Improvements in Weighing-apparatus.
A communication from CARL SCHMIDT, of Berlin, S.O. Prussia, in the Empire
of Germany, Civil Engineer.
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, 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 :-
This invention relates to apparatus for automatically weighing constant masses
or quantities of granular and powdery substances.
Owing to the special and novel construction of this apparatus it is rendered
possible, by means of a hand-worked lever, to set in motion simultaneously or in
succession several mechanical devices and thereby obtain an automatic feed or
inflow of the material into the receptacle which acts as a weight-scale or scale-pan,
as well as an accurate weighing of the same by means of a special filling apparatus,
and after a certain movement of the beam, to bring about an automatic opening of
the bottom valve, and further the automatic restoration of the machine and all its
parts to the original position, without any difficulty or obstacle arising from the
alternate or reversed action of any of the working parts, and from the in and out-flow
of the weighed material.
In the accompanying drawings,
Fig. 1 is a side elevation of the apparatus as it appears before the commencement
of the feed ;
Fig. 2 is an end elevation of the same;
Fig 3 represents a modification of the slide G.
Fig. 4 is a vertical section on the line x x of Fig. 2 showing the bottom valve as
ready for opening.
Fig. 5 is a section similar to Fig. + but with the bottom door locked and the
upper door or valve open.
Fig. 6 is a vertical section through the anxiliary, hopper and receiver and
Fig. 7 is a section through the feed roller.
The apparatus comprises a weigh-beam A, with two equal arms, whereon
at a the loading scale or scale pan B B and at a 2 the weight-scale or pan, are
suspended on knife-edges in a straight line with the point of support a of the
beam. With the loading-scale or scale-pan is connected a small auxiliary receiver b.
Both are closed at the bottom by a bottom-valve or clack D, common to the two,
pivoting on the fixed bolt d, and fitted with a counterweight d'.
Above the weighing-scale, on the fixed frame E of the apparatus is placed the
hopper F, with the small auxiliary hopper for the feed of the auxiliary receiver b.
Between the outlet opening of the hopper F and the weighing-scale is arranged a
flat sliding disc, plate or valve G extending to the fixed frame, and which may be
moved by hand by. the lever arrangement H h. The lower edges of the inlet
hopper Fare surrounded by brushes, which rest on the upper surface of the
sliding valve G. A bent bolt g, affixed to the valve G, serves to hold the beam
stationary, when the sliding valve G has been withdrawn and has opened the inlet
for the feed. To this end, the scale-beam A is provided with a projecting pin a 3
under which. the bent bolt g.slides as shown in dotted lines in Fig. 5. In place of
the flat slide or valve G, may be substituted, if desired, a sector-slide or valve G
TD

page_text: Fig. 3, swinging on a fixed point, which also is provided with a suitable click or
pawl to hold the weighing scale fixed during the full inflow-period and, during the
subsequent or later period of inflow, releases it and allows the weights and the
substance weighed to balance by means of the beam. This catch or stop-motion
(to be chosen for the weighing-scale) may be constructed in various ways but
always so that the scale must be held fast during the full flow, and only released
towards the end so that the balance-beam may have free play.
Below the small hopper f there is located a feed device, consisting of a cylinder
er roller I, attached to the fixed frame of the apparatus, whereof the deep sides
close the outlet opening of the hopper in two directions, while the 3rd and 4th sides
are closed by the fixed brush K and by the brush L pivoted at 1 after the manner
of a clack-valve and both fitting tightly against the surface of the cylinder or
roller. Firmly connected with the movable brush L is an arm provided with
a projecting finger 13, and carrying at its free end the small roller 2. This latter,
when the arm is at its highest point, takes up the position indicated in dotted
lines in Fig. 1 where it rests upon the projecting shoulder or offset m¹ of the double
or bell-crank lever M pivoted to a portion of the fixed frame of the apparatus.
The pivot-shaft of the hand-lever H carries in addition to the finger-arm h,
the levers N and R, which partake of the movements of H. On the lever N is
provided a driver n, which, on the upward movement of the hand-lever H comes
into contact with the finger 13 of the roller-arm /, whereby the latter is pressed
upwards.
The rotating shaft of the feed-roller I as shown most clearly in Fig. 7 carries
also (besides this latter) a loosely mounted pulley i, round which passes a cord
secured to the end of lever N, which at its other end is secured to the free end
of the lever O, mounted loosely on the shaft h₁ of the hand-lever H, so that, by its
own weight this lever O keeps the cord tightly strained around i.
Two pawls 2 and 3 secured to the feed-roller, working on the boss of the loosely
mounted pulley i, serve as drivers for the roller I, during the rotation in one
direction of i; while during the rotation in the opposite direction the driving action
of the said pawls 2 and 3 ceases.
The working of the feed-roller I can be effected in other ways than as here
shown and described; for example by spur-gear or chain-wheels, but in all cases in
connection with the automatic movements consequent on the descent of the haud-
lever H.
The closure of the bottom valve D is maintained by a lever P, pivoted to the
weighing scale or pan B B₁, and which at p is provided with a catch, projection or
shoulder to support the projecting pin d2 on the forward end of the valve. On the
fixed frame E, at e is pivoted the upper end of a rod Q whereof the lower end is
bent inwards. The lever R, securely mounted on the pivot shaft h¹ (of the hand-
lever H) has for its purpose, at the end of its downward movement, and by means
of its pin to displace the suspended rod Q by acting on its lower bent end, so as
to sever the connection between the lever P and the bottom valve D, by displacing
the projection or shoulder p of the lever, through the lateral pressure exercised on
the pin p1 of lever P by the suspended rod Q.
On the fixed frame at e the cylinder S of a piston (or pneumatic) brake is
suitably pivoted, while the movable piston-rod s is jointed to the arm 2 projecting
upwards from the hand-lever H.
The method of working of the above described weighing apparatus is as
follows;-
Normally the weighing scale or scale pan is in its highest and the scale holding
the desired weights in its lowest position.
The material to be weighed runs into the inlet-hopper F out of a reservoir of
any suitable dimensions and capacity; and the lever H is raised by hand until it
comes to rest upon the fixed stop e 2.
In this movement the lever arm h participates until its finger h3 towards the end
of its displacement, comes into engagement with the projecting nose g¹ of the slide

page_text: or valve G, and exerts a pressure thereon whereby the opening of the feed or
inlet-valve is effected.
The material to be weighed now flows freely into the weighing scale B B until
the former extends from the bottom of the latter up to the outlet of the hopper F,
when the flow ceases automatically. Now, as the sectional area of the outlet from
the hopper F is smaller than that of the top of the weighing-scale, it follows that,
after the feed stops, the material has taken a sloping conical form at the surface.
But as the outlet of the hopper F is still sufficiently large to quickly fill the
weighing scale to nearly the uppermost edge thereof, the attendant may now release
the hand-lever H from its engagement with the stop e 2.
Thereupon through its own weight, the lever H swings back again into its
former position, while the second finger 4 of the lever arm imparts to the slide
or valve G a return sliding motion, in consequence of which the latter cuts
through the solid column of the material that has run into the scale, level with its
surface, and severs the connection with the feed.
Owing to the natural angle of repose of the material in the receptacle B B¹ a
space is left between the walls of this receptacle and said material and this space
is nearly filled by the material pushed in front of or displaced by the edge of the
slide G when the latter is operated to shut off the feed.
The capacity of the weighing scale is such that the quantity of the material
already supplied to it through the main hopper F almost equals the specific weight
placed in the scale C. Now in order to supply more material to that already in
the receptacle B B so that it may equal the weight in the scale C a renewal of
the feed is automatically effected and this takes place through the auxiliary
bopper as next described. The lever arm 4, in cousequence of the previous
upward motion of the hand-lever H, is moved to its highest position, where it is
held fast by the projecting shoulder or seat m' of the double or bell-crank lever M
engaging the roller 12. There is thus formed between the brush-valve L and the
feed-roller I, an opening through which the material contained in the auxiliary
hopper would constantly flow into the auxiliary receiver b were it not that the
natural angle of repose of the material causes the outlet of the auxiliary hopper
to be kept closed by the material. The auxiliary feed in fact commences only at
the moment when the feed-roller I begins to rotate under the influence of the
pulley and cord i actuated by and during the descent of the lever N.
So soor: as this subsequent or accessory feed brings about an equilibrium in the
balance-beam (so as to cause the weight scale C to rise) the pin e at the top of
the rod, carrying the said scale, strikes against the arm m of the bell-crank
lever M and thereby displaces the support hitherto given to the roller 2 on the
lever-arm, so that the latter suddenly falls and stops the further supply by
closing the brush-valve L upon the feed-roller I.
The filling of the weighing-scale B B having been thus completed, the opening
of the bottom valve or outlet D to discharge the contents of B B' has next to be
effected and is brought about in the following manner;-
The arm R, descending with the hand-lever H comes in contact with the
suspended rod Q, and this, being thereby driven back, destroys the connection
between the lever P and bottom-valve D by withdrawing the supporting shoulder p
out of engagement with the pin d, so that D immediately drops, under the pressure
of the material in the receptacle B B', and allows the material to be discharged.
As soon as the receptacle B B is empty, the counter-weight d₁ on the rear-arm of
the valve D closes the latter.
The bent or angle-bar g attached to the slide-plate G by engagement with the
pin or projection as keeps the balance-beam A steady during the whole period of
the preliminary and approximate filling of the scale. This engagement is effected
when the scale B B₁ is empty and the corresponding end of the bean is naturally
tilted up, so that when the slide-valve G is drawn back to start the feed, the bolt g
is brought under the projecting pin a 3 of the beam so as to prevent the downward
movement of the latter under the influence of the load. This precaution is

page_text: adopted to prevent such movement, consequent upon the sudden rush or inflow of
the material when the valve is opened. Only when the slide G is moved back to
cut off the main feed-supply, and the bolt g is thereby withdrawn from engagement
with the pin a³ can the weigh-beam A act freely. The piston brake applied to
the hand lever H through the arm H2 of the latter has for its object to secure the
easy return of the automatically descending parts to their temporary position of rest
prior to a repetition of the whole process as well as gradually to stop the rotation
of the feed-roller I.
Inasmuch as the filling of the weighing scale with material is intended to
coincide pretty nearly with the weights placed in the opposite scale C, some
mechanical device is required to adjust the capacity of the former to the specific
gravity of the material. For this purpose, the weighing scale is made adjustable,
as shown in the accompanying drawings, by being formed in two parts B and B
which are so connected as to be capable of sliding one into the other. This
adjustability in point of capacity can however be obtained in various other ways.
In order to provide against small inequalities in the results of the various
weighings, the weighing apparatus is provided with a well-known regulating
device, consisting of the two-armed lever T fitted with a sliding counterpoise t.
For the purpose of testing the accuracy of the weighings, a small tappet U
pivoted on a stud u is arranged on the fixed frame E, which can be placed by the
handle u, in a vertical position, so that thereby the lever R or N may be arrested
nearly at the end of its downward movement, and so prevented from opening the
bottom valve D or causing the discharge of the contents of the weighing
scale B B¹.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is ;--
1. A weighing apparatus whereof the weighing scale (B B₁) after the hand-
operation of a horizontal slide or valve such as G or of a sector-slide or valve
such as Garranged below an inlet-hopper (F) is quickly filled with the material
to be weighed so that the quantity thereof nearly counterbalances the weight
placed in the opposite scale (C) while a stop-bolt such as g actuated by the slide-
motion and acting upon a pin (a 3) affixed to the balance-beam (A) holds the latter
in its place until the slide (G or G₁) is automatically closed by reason of the
weight of a lever-arrangement (Hh) acting upon it and in returning cuts off the
top of the material delivered into the weighing scale and stops the feed substantially
as described and illustrated in the accompanying drawings.
2. In weighing apparatus such as described in Claim 1 a device whereby the
supplementary feed for the attainment of the total quantity to equal the weights
duly provided in the other scale from the auxiliary-hopper (f) in connection with
the chief inlet hopper (F) into the auxiliary receiver is effected by a feed-
device consisting of a roller such as 1 with driving mechanism such as i¹ and its
actuation by levers such as H and N. during their downward movement a
regulated working being thereby imparted to the mechanism and roller I with the
co-operation of a brake-motion S substantially as described and illustrated in the
accompanying drawings.
3. The combination and arrangement of parts constituting the complete
weighing apparatus substantially as described and illustrated in the accompanying
drawings.
Dated this 17th day of January 1895
BOULT & WADE,
Agents for the Applicant.