Improvements in Machines or Apparatus for Weighing Tea, Coffee, and other Materials of a Granular or Powdered Nature.
Year: 1894

page_text: Date of Application, 30th May, 1894-Accepted, 14th July, 1894
COMPLETE SPECIFICATION.
Improvements in Machines or Apparatus for Weighing Tea, Coffee,
and other Materials of a Granular or Powdered Nature.
I, GEORGE HALLAM DRIVER of 210 Euston Road, in the County of London,
Electrical Instrument Maker, 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 :-
In the Specification of Letters Patent granted to me dated the 18th March
1892, No. 5333, I have described a machine or apparatus for weighing tea, coffee,
cocoa, and other material of a granular or powdered nature, wherein the main
supply of material from a hopper to a scale pan is controlled by a main slide or
slides operated by an electro-magnetic device or devices the circuit or circuits of
which is or are controlled by a secondary weighing device carried by a main
weighing device, and a smaller and final supply of material is controlled by another
slide or slides operated by an electro-magnetic device controlled by the main
weighing device.
Now my present invention has reference to improvements in machines or apparatus
of the kind referred to, the object being to simplify the construction and improve
the working and efficiency thereof.
For this purpose it relates to an improved construction of mechanism for
controlling the flow of material from the hopper to the scale pans; to an improved
arrangement of electric circuits and means for controlling the same, and to an
improved construction of hopper, all as I will now proceed to explain by reference
to the accompanying drawings, in which
Fig. 1 is an end elevation,
Fig. 2 a plan; and
- Fig. 3 a side elevation, partly in section, showing my improved construction of
hopper and the mechanism for controlling the flow of material therefrom to the
scale pans of the weighing apparatus below.
Fig. 4 is an underside view of the said controlling mechanism together with the
plate for carrying the same and attached parts.
Fig. 5 is a side elevation showing parts of the main and secondary weighing
devices and some of the electrical contacts carried thereby.
Fig. 6 is a diagrammatic view showing various parts of the machine and the
several electrical connections and devices for working the same.
Figs. 7 & 8 are detail views hereinafter referred to.
1 is a hooper secured at its lower end to a plate 2 in which is the main feeding
aperture 3 arranged above the uppermost, for the time being, of a series of scale
pans carried by the secondary and main weighing devices, all of which are or may
be constructed and arranged in the manner described and shown in my said former
Specification.
The aperture 3 is, according to my present invention, controlled by hinged or
pivoted plates or shutters, of which there are, in the example shown, three pairs,
nainely, 4, 5, and 6, which are arranged to be moved into their closed positions, in
the order mentioned, by electro-magnetic devices so as to gradually cut off the
supply of material to the scale pans, and to be afterwards opened by gravity when
the circuits of the said electro-magnetic devices are broken. For this purpose the
pair of shutters 4 are pivoted at 7 and provided at one end with pins 4 connected
by a pair of inclined links 8 to the lower end of a vertical rod 9, the upper end of
which is jointed to the long arm of a lever 10 pivoted to a support 11, and to the
short arm of which is jointed a vertical rod 12 carrying the armatures 13 of a

page_text: group of electro-magnets 14, and also a vertically adjustable sleeve 15. With this
arrangement, when the circuit of the electro-magnets 14 is completed as hereinafter
described, the armatures 13 will be drawn down and the shutters 4 caused to close,
it may he against a pair of stops 16 arranged at opposite sides of and below the
aperture, so that the said shutters 4 will partly close this aperture and partly cut
off the main supply of material therethrough, and on the breaking of the circuit of
the said electro-magnets, the shutters 4 will fall by gravity into their open position,
the extent of opening being limited by reason of the adjustable sleeve 15 abutting
against the underside of the plate 2. The pairs of slides 5 and 6 are operated and
controlled by similar mechanism indicated by similar reference figures, but with
the addition of the index letters a and b respectively to the various parts thereof.
The adjustable sleeves 15 and 15b, corresponding to the shutters 5 and 6
respectively, are however preferably enlarged, as shown, to form balance weights,
so that in conjunction with the rods 12 and 12" and armatures 13ª and 13° con-
nected therewith, they each serve to nearly balance the weight of the corresponding
shutter and remaining parts and thereby enable the electro-magnets to operate the
shutters and connected parts with a smaller current than would otherwise be
necessary, but so nevertheless as to allow of the shutters readily opening by
gravity when the circuits of the electro-magnets are broken. The shutters 4 being
lighter than 5 and 6, the corresponding sleeve 15 need not be specially enlarged or
weighted for the purpose mentioned. The support 11 to which the lever 10 is
pivoted, is provided with a screw threaded extension 11" that extends through a
cock piece 2ª and is preferably fitted with adjusting nuts 11 so that the height of
the fulcrum of the said lever 10 can be adjusted, when necessary, for the purpose
of varying the extent to which the shutters 4 are caused to close. The shutters 4, 5,
and 6 are connected to their respective pairs of links 8, 8ª and 8b by pins or
extensions 4, 5 and 6 that are fixed to the respective shutters. The shutters 5
are each formed with a notch 17, so that when they are closed against each other,
the two notches will form a small or secondary feeding aperture through which a
small stream of tea or other material will continue to fall, after the shutter 4 has
been more or less closed, until the exact weight required of such material has
entered the scale pan below. The said shutters 5 are arranged to close against the
lower inclined edges of two stops 16* which, as well as the inclined edges of the
stops 16, may advantageously be formed as knife edges in order that any material
such as tea, caught between them and the shutters 5 and 4 respectively will be
sheared and so enable the said shutters to properly close. The larger and lower
pair of shutters 6 are without notches so that when they are closed against each
other, they will cut off the small stream of material flowing through the aperture in
the shutters 5, and together form a V-shape receptacle closed at the ends by
corresponding V-shape plates 18, one of which may be carried by each shutter 6 as
shown. 4, 5 and 6° (Fig. 3) show the closed positions of the parts of shutters 4, 5
and 6 respectively. 2b are guides for the rods 9, 9, 9º.
°
19 is a switch lever pivoted at 19 to the underside of the plate 2 and provided
with an insulated contact piece 19b adapted, by operating the said lever, to be
inserted between and withdrawn from two fixed spring contacts 20 for the purpose
of making and breaking the main circuit respectively, when starting and stopping
the machine, the said switch lever serving at the same time to operate an end ways
movable bar 21, constituting a belt shifter, for the purpose of throwing a stirrer 22,
arranged at the lower end of the hopper 1, in and out of action in the manner
described in my said former Specification. 23 and 24 are pins fixed to the said
bar 21 and adapted to act respectively against one of the shutters 5 and 6 so as to
close both pairs of shutters 5 and 6 when the switch lever is operated to put the
machine out of action.
In Fig. 5, 25 is a part of a frame hung from the front end of the main weighing
beam 25 (Fig. 6), and corresponding to the frame referred to in my said former
Specification as the link or stanchion 43. 26 is the secondary weighing beam
forming part of the secondary weighing device pivotted on the frame 25*, and

page_text: connected thereto by an adjustable weighing spring 26*. These main and secondar
weighing devices are constructed and arranged substantially in the manner describe !.
in my said former Specification and therefore will not need to be herein further
described. To the frame 25° are fixed two adjustable contacts 27 and 28 that are
in connection through suitable conductors 27 and 28 with the windings of the
group of magnets 14 and 14ª respectively as shown diagrammatically in Fig. 6.
29 is a spring contact that is carried by the secondary beam 26 and is placed in
electrical connection through the said secondary and main beams 26 and 25" and
conductor 30, with one pole 31 of an electric generator 31 when the machine is in
use, the circuit being at this time completed through the switch contact 19 and
spring contacts 20. 32 is a contact carried by and electrically connected to the
rear end of the main beam 25 and adapted, when raised, to make contact with a
metal cock piece 33 which is in electrical connection by conductors 34, 34" and 34°
with the group of electro-magnets 14. To ensure a good rubbing but yielding
connection with the contact 32, when the latter rises, the cock piece 33 has con-
nected thereto two metal spring plates 33ª arranged at an angle to each other as
shown in side and end elevation in Figs. 7 and 8 respectively and between which
the said contact can enter. By this means any oscillation of the beam, will be
prevented from affecting the constancy of the contact. In series with the
conductors 34, 34 is arranged the electro-magnet. 35 carried by the secondary
beam and serving to release the scale pans 36 in the manner described in my said
former Specification, when the correct weight of material has entered the uppermost
pan. 37 is a conductor with branches 37 for placing the groups of electro-
magnets 14, 14, and 14 in connection with the other pole 31° of the electric
generator 31. The operation of the machine is as follows:-Upon moving the
switch lever 19 into a position to complete the circuit between the conductors 30
and 30 through the contact 19 and 20, the belt shifter 21 will be moved end ways
so as to throw the stirrer 22 into action and move the pins 23 and 24 away from
the shutters 5 and 6 so as to permit these shutters to open by gravity. Material
in the hopper 1 will then fall through the aperture 3 of the plate 2 into the
uppermost scale pan 36 until the weight of such material partly overcomes the
action of the spring 26* and causes the secondary beam 26 to gradually tilt so as
to bring the contact spring 29 thereon first into connection with the contact 27, so
as to complete the circuit of the electro-magnet 14 and cause the same to close the
shutters 4 and thereby partly close the aperture 3 and cut off the greater part of
the supply of material therethrough, and then to come into connection with the
contact 28 so as to complete the circuit of the electro-magnets 14" and cause the
same to close the shutters 5 through the opening 17 in which, however, a small
stream of material will continue to fall until the exact weight of such material.bas
entered the scale pan. When this takes place, the main beam 25 will tilt and
bring the contact 32 thereon into electrical connection with the cock piece 33,
whereupon an electrical circuit will be completed through the conductors 34, 34*,
34, 37 and 37 so as to energise the electro-magnet 35 and release the charged
scale pan, and also to energise the electro-magnets 14° and close the shutters 6,
thereby completely cutting off the supply of material from the hopper. The main
and secondary beams then return to their original positions and break the circuits
of the electro-magnets 14, 14, 14 and 35 so as to allow the shutters 4, 5 and 6 to
fall open by gravity and a fresh scale pan 36 to be held in position below the
feeding aperture, whereupon the foregoing operations will be repeated.
35 is a push whereby the circuit of the electro-magnet 35 can be completed to,
release the scale pans independently of the weighing mechanism when desired.
To prevent waste of tea or other material by the premature opening of the lowe..
shutters 6 before a fresh scale pan is in position below the feeding aperture, I
employ an electro-magnetic device, hereinafter called a relay, comprising two
electro-magnets 38, 38ª, and a pivoted armature 39 arranged between them." The
electro-magnet 38 is connected with a conductor 40, one end of which is connected

page_text: with the pole 31 of the electric generator, whilst its other end is connected with a
contact piece 41 carried by but insulated from the main beam 25 (Figs. 5 and 6),
and above which is an adjustable contact 42 carried by and in metallic connection
with the secondary beam 26. The electro-magnet 38 is arranged in the con-
ductor 34. The armature 39 is connected with the conductor 345 and is adapted
in any known or convenient manner, as by a bent spring, to rest in either of its
extreme positions until attracted by the opposite magnet 38 or 38". 43 is a contact
connected to the conductor 30 and against which the armature 39 is caused to bear
when attracted by the electro-magnet 38º. With this arrangement, when the
circuit of the electro-magnets 14' is completed by the contact 32 rising against the
spring contact plates 33 as herein before explained, the electro-magnet 38 will
attract the armature 39 to the right and against the contact 43 in which position it
will remain and keep the electro-magnets 14° energised and the shutters 6 closed
until the secondary beam returns to its original position and completes the circuit
of the electro-magnet 38 through the contacts 41 and 42, when the armature 39
will be pulled to the left, and break the circuit of the electro-magnets 14', thereby
permitting the shutters 6 to open by gravity. This arrangement also ensures
should the machine be in a state of vibration, the closing of the shutters 6 at the
first contact of the contact 32 with the spring contacts 33 for each weighing
operation.
In the arrangement hereinbefore described and shown in full lines in Fig. 6, the
electro-magnets 35 and 14° are arranged in series with each other. They may,
however, if desired, be arranged in parallel, as for example by breaking the
connection between the conductors. 34 and 34* with the cock piece 33 and
conductor 34° respectively, and connecting the cock piece 33 with the conductor 34
by the conductor 34°; the conductor 34 with the conductor 34° by the con-
ductor 34°; and the conductor 34 with the. conductor 37 by the conductor 34*, as
indicated by the dotted lines in Fig. 6. In this case the completion of the circuit
of the electro-magnet 35 may be made dependent not only upon the tilting of the
main beam 25 but also upon the operation of another machine, such as a packing
machine, with which the weighing machine is combined.
The weighing mechanism may advantageously be enclosed in a dust proof casing
through which the boss, carrying the scale pans, projects, a sufficiently large
aperture however being left in the end of the casing to permit of the necessary
movements of the said boss. The magnets 14, 14, 14" and armatures may also
with advantage be enclosed in a dust proof case through the top of which the
rods 12, 12 and 12" work.
To permit of ready access to the hopper for removal of bodies such as pieces of
wood, metal foil and the like such as sometimes enter the hopper with the material
to be weighed and interferes with the proper working of the machine, the said
hopper may advantageously be constructed with a door 1 hinged at 1 and normally
retained in the closed position by a suitable fastening device 1°. A saw cut or slit
is provided above the door 1* of the hopper 1 through which a thin plate 1ª can be
inserted so as to cut off the supply of tea or other material from the hopper above
while such obstruction is being removed.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A weighing machine or apparatus of the kind herein referred to wherein the
flow of material from a feeding receptacle to a scale pan is controlled by pairs of
shutters that are closed in succession by electro-magnetic devices brought into
action by the weighing mechanism, and are opened by gravity on the breaking of
the circuits of the said electro-magnetic devices, substantially as herein described.
2. In a weighing machine or apparatus provided with shutters such as referred
to in the preceding claim, the combination with the electro-magnetic devices for

page_text: effecting the closing movement of the said shutters, of a relay constructed, arranged
and operating substantially as hereinbefore described with reference to and shown
in Figs. 5 and 6 of the drawings annexed for the purpose specified.
3. The combination and arrangement of parts constituting my improved
mechanism for controlling the flow of material from a feeding hopper to the scale
pan or pans of weighing apparatus substantially as described and shown.
Barca s oven day on May 1034.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.