Improvements in Machines or Apparatus for Weighing Tea, Coffee, Cocoa, and other substances of a Granular or Powdered Nature.
Year: 1892

page_text: Date of Application, 18th Mar.; 1892
Complete Specification Left, 17th Jan., 1893-Accepted, 18th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in Machines or Apparatus for Weighing Tea, Coffee,
Cocoa, and other substances of a Granular or Powdered Nature.
I, GEORGE HALLAM DRIVER of 210 Euston Road, London N.W. in the
County of Middlesex, Electrical Instrument Maker do hereby declare the nature
of this invention to be as follows:-
My invention relates to a machine intended to weigh out tea, coffee, cocoa, and
other substances of a powdered or granular nature expeditiously from the bulk into
quantities of a specified weight and with greater accuracy than hitherto, and
further to effect this operation automatically.
This invention comprises the following essentials ;-
1. A hopper to contain the material to be weighed placed above a pair of scales
and provided at or near the bottom with holes or openings, hereinafter called
sluices, which sluices are opened and closed by means of electro-magnets_acting
upon suitable mechanism, so regulating the flow of material into the scale pan
below. To ensure a regular flow the hopper is provided with a shaft carrying
projections, which when rotated either by hand or power, stirs the material to be
weighed in the immediate vicinity of the sluices; or a propelling screw as used in
flour mills, or any other well known device may be used."
2. Accurate scales, preferably of the "counter weighing machine" type, and for
greater expedition, in place of the ordinary single pan I place a series of pans
which on a catch being released are free to revolve about a common centre.
This catch is released electrically in a manner to be hereinafter described when
the required weight is present in the pan immediately under the sluices.
On the series of pans being released they turn through part of a revolution
sufficient to tilt or turn out the weighed material from the pan which was uppermost
& first fed, and bring the next succeeding pan into position for another weighing
where it is detained by the catch while receiving the required weight, when upon
completion it is also released, and so on with the series continuously.
3. Suitable electrical devices hereinafter named for operating and controlling the
sluices and other mechanism, when connected with the source of electricity in the
manner usual in such cases.
One mode of carrying my invention into effect is as follows;-
I arrange the hopper and its stirer, or propelling screw, above the scales, in such
a manner that the uppermost scale pan of the series lies horizontally directly
beneath the sluices but leaving just enough space for the series to revolve.
The sluices are opened and closed at the right moment. by means of slides
actuated by levers connected with the armatures of electro-magnets.
To enable the machine to weigh both quickly and accurately I provide as in
similar machines two or more rates of feed by graduating the size of the sluices.
The larger sluices are closed when the weight is approximately reached and a
small-feed continues until the exact weight is present in the pan.
The scales I prefer using are those of the "counter weighing machine" type,
fitted with the usual knife edges. Suspended at either end of the top beam from
knife edges are links, one carrying the rotary series of scale pans, the other the
desired weight together with the counterpoise of the series of pans and their
attendant mechanism.
A. contact is made with the beam and an insulated contact pillar by means of a
combined rigid and flexible contact piece conveniently attached to the beam. The
rigid contact piece resting upon the insulated contact pillar supports the end of
the beam carrying the weight until the desired amount is supplied to the pan.

page_text: 1 De nexible contact which is in electrical connection with the rigid one is necessary
to prevent, when the balance is very nearly arrived at, any false breaking of the
contact on the part of the rigid piece due to the impetus from the fall of the
material in the pan or from accidental shaking of the machine. Any flexible
contact, such as a spring, will answer the purpose, but I specially prefer to use a
platinum chain which, reaching slightly lower than the rigid piece, is not lifted
right off the under contact pillar by the slight oscillations of the beam due to
vibrations, although the rigid one may be, but still continues in contact until the
beam decidedly tilts with the right weight. Such a chain is preferable to a spring,
being more accurate-it always breaks contact at exactly the same position of the
beam, has less friction, and does not tend to help the beam to rise.
The beam is also fitted with an adjustable stop to prevent it oscillating unduly.
The series of rotary scale pans are fixed by means of spokes or supports, to a hub
which revolves on a ball or other nearly frictionless bearing attached to a secondary
weighing contrivance, such as a small beam pivoted at or near its middle, or a
repetition of the larger parallel beams of the "counter weighing machine" type.
In either case this secondary weighing contrivance is suspended by means of
knife edges, or a pivot, from a link of a special form suspended from the main beam
& held in position by the bottom "hook," or "guide," (being part of what is generally
known in the scale trade as "bottom work").
Instead of using weights in this secondary weighing contrivance I prefer to use a
spring which allows of a gradual movement of this smaller beam as the weight
accumulates in the scale pan. Conveniently attached to this secondary beam are
two electrical contact pieces which engage with two others insulated from the
general framework of the scales-with one by the action of the spring when the
pan is empty, and with the other when the weight of material in the pan has moved
it sufficiently against the action of the spring.
This secondary weighing device is only approximate and is used simply to obtain
the required electrical contacts for operating and controlling the larger sluice or
sluices; one of the insulated contacts opening, and the other closing them. In the
case of two or more large sluices a similar number of insulated contact pieces would
he necessary, and these additional contacts should be flexible so as to allow the
beam to continue moving and make successively the additional contacts required in
such case.
In this way a number of different size sluices can be closed separately
when a predetermined portion of the weight has entered the scale pan. These
sluices would be simultaneously opened again when the pan being empty the beam
by the action of the spring makes contact with the one, which in the case of the
single large sluice served to open it.
Another way in which the large sluices may be operated without the use of an
extra weighing beam suspended from the link of the main weighing machine, is to
make some part of the spokes, or supports for the pans, flexible, so that on the
weight entering the pan this flexible part is depressed, and is followed for a pre-
determined distance by a flexible contact piece insulated from the beam, as in the
previous instance, one contact being necessary for each large sluice operated.
The action in this case is as follows:-Directly a pan is in position ready to
receive its load a contact is made with the insulated piece or pieces, and the large
sluices are opened by means of electro-magnets, and at the same time a relay
armature is held over; but as the flexible contacts are prevented from following
more than their predetermined distance (by means of set-screws insulated from the
beam generally) the movements of the flexible portion of the pan support (due to
the accumulation of the material in the pan) the contact is thereby broken; then
by means of the relay (one for each sluice) another circuit is made which closes its
respective sluice.
Insulated wires made as flexible as possible convey the current from the different
parts of the machine to the electro-magnet and insulated contacts moving with
the beam, or wires with their ends dipping in mercury cups properly connected
may be used.

page_text: To economise the electric current suitable resistances may be used.
In all cases where the current is spoken of as passing through the knife edges,
or pivots, subsidiary flexible connections may be used.
The action of the machine is as follows;-Supposing the machine to be adjusted
ready for working, it is connected to the source of electricity such as a battery or
a dynamo, by means of two terminals, and from one of these the current flows
through a wire to the contact pillar, thence by means of the combined rigid &
flexible contact before mentioned, along the scale beam until it reaches the centre
knife edges on which the main beam turns; here it splits into two portions, one
portion passing through the knife edges, down the main beam support, thence along
a wire to the magnet coils which open the smallest sluice, then through the coils of
a relay (the armature of which is thereby held over) back to the other terminal.
The remainder continues along the beam through the knife edges or pivots on
which the secondary beam turns, (or in the case of the flexible pan support to the
flexible piece itself) thence along the secondary beam, and as the pan is empty and
the beam by the action of the spring is pressing against the insulated contact piece
connected by means of a flexible wire or mercury cup, to the magnet coils which
open the large sluice or sluices, and so back to the other terminal. So that now
all the sluices being open the material continues to flow into the pan below, the
secondary beam is gradually tilted and moves away from the contact breaking the
current and leaving the large sluices open until sufficient has fallen into the pan to
make the next contact, or contacts, which close the large sluice or sluices.
The smallest sluice being open continues feeding until the exact weight is
present in the pan when the beam tilts, breaking the combined rigid and flexible
contact which stops the current which excited the relay coils allowing its armature
to Hy back and put in circuit the magnet coils on the secondary beam (which
serve to release the series of pans) and also the magnet coils which close the small
sluice.
The series of pans being now released are able to revolve sufficiently to discharge
the contents of the loaded pan and bring another pan into position for another
weighing, the same operations being repeated for each pan in succession.
The series of rotary scale pans are so arranged that the centre of gravity of each
pan together with its load is not in vertical alignment with the centre of the hub;
this being the case, when the series of pans are released the loaded one falls to the
side on which it has been inclined. By this means the pans can all be made to
lean one way and discharge their contents in the same funnel which directs the
material into the usual receptacles placed below; or by employing say two pans
one leaning to one side and one to the other the material can be shot alternately on
either side, thus permitting when the machine is going very fast the service of
attendants on either side of the machine to place and take away the packets, tins,
or whatever receptacles may be used.
To enable the movements of the series of rotary pans to be regulated, suitable
teeth or indentations to a like number with the pans are cut in the hub carrying
the pan supports or other convenient part which revolves with the pans. These
teeth or indentations engage with a catch attached to the armature of an electro-
magnet, when held in or against these indentations or teeth by a spring.
This catch holds the pans stationary and in position while each receives its load,
but releases the series when pulled out of engagement with the teeth or indentations
by the electro-magnet brought into action as before mentioned, when the beam
tilts with the required weight.
The electro-magnet to operate this catch is fixed to the secondary beam and
therefore slightly tilts with it and the series of pans.
To start and stop the machine I provide it with an ordinary electrical switch to
which are attached levers so that when the supply of current is turned off, it at
he same time actuates the slides and closes all the sluices thus preventing any of
he material running out to waste,

page_text: In place of the attendants I may arrange additional mechanism to supply, take
away, and, in the case of lead foil and similar packets, close them automatically.
Dated this 18th day of March 1899
GEO. HALLAM DRIVER.
COMPLETE SPECIFICATION.
Improvements in Machines or Apparatus for Weighing Tea, Coffee,
Cocoa, and other substances of a Granular or Powdered Nature.
I, GEORGE HALLAM DRIVER, of 210 Euston Road, London, N.W. in the
County of Middlesex, Electrical Instrument Maker, do hereby declare the nature
of this invention and in what manner the same is to be performed to be par-
ticularly described and ascertained in and by the following statement :-
My invention relates to machines or apparatus designed to automatically weigh
out substances of a powdered or granular nature such as tea, coffee or cocoa from
the bulk into quantities of a specified or predetermined weight, in a quicker and
more accurate manner than has heretofore been usual.
In a machine for this purpose constructed according to this invention the main
supply of the material (hereinafter referred to as tea) from a hopper to a scale pan,
is controlled by a main slide or slides operated by an electro magnetic device the
circuit of which is controlled by a secondary weighing device that comes into
operation to cut off the supply of tea before the required weight thereof has
entered the scale pan, and which is carried by the main weighing device, the smaller
and final supply of tea being controlled by another slide or slides operated by an
electro-magnetic device controlled by the main weighing device.
To insure a regular flow of tea the hopper is provided with a stirring device
which, when rotated by manual or other power, stirs the tea in the immediate
vicinity of the feeding apertures. In carrying out my invention I employ a series
of scale pans mounted to turn about a centre. These pans are normally held in
position by an electro magnetic device the circuit of which is controlled by the
main weighing device, the arrangement being such that when the required or pre-
determined weight of tea has entered a scale pan, the main weighing device will
move and cause the electro magnetic device to release the scale pans and allow them
to partly rotate so that the tea will be discharged from the pan into which it fell,
and a fresh pan will be brought into position for use.
In the accompanying drawings,
Figs. 1 and 2 are respectively a side elevation with parts of the casing removed,
and a plan, of a weighing machine constructed according to this invention.
Fig. 3 is an underside view of the mechanism employed for controlling the flow
of tea from the bottom of a hopper to a scale pan below, and for stirring the tea in
the bottom of the hopper.
Fig. 3 is a detail view.
Fig: 4 is an end elevation of the upper part of the machine showing an electro-
magnetic arrangement for operating the small slides.
Figs. 5 and 6 are plan views of the end portions of the weighing devices and
adjacent parts.
Figs. 7 and 8 are cross-sections on the lines A-B and C-D respectively of Fig.1.
Figs. 9 and 10 are rear and front end elevations of the weighing, releasing and
contact making devices.
Figs. 11 and 12 are elevations of opposite sides of the secondary weighing device,
scale pans and electro-magnetic releasing device suspended from the front end of
the main weighing. device.
Fig. 13 is a diagrammatic view.
Figs. 1.and 2. are drawn to a smaller scale than the other figures,
The remaining figures are hereinafter referred to.

page_text: 1 is a hopper connected at the bottom to a plate 2 in which is a hole 3 forming
the main feeding aperture for the tea. This aperture is controlled by two main
slides 4, 4ª each formed with a notch 4* that forms, when the slides are moved into
contact with each other, a smaller or secondary feeding aperture 3* that is con-
trolled by two smaller slides 5, 5. The several slides are arranged to work between
suitable guides, as for example the guide rollers 6, which are pivoted to the under-
side of the plate 2. Pivoted rollers 6* serve to support the inner ends of the slides 4.
The main slides are each operated by the long arm 7 of a lever pivoted at 8 to the
underside of the plate 2, and the short arm 9 of which engages an arm 10 fixed to a
pivoted rock shaft 11. This shaft is provided with a third arm 12 that engages
one arm of a bent lever 13 pivoted at 14 and the other arm of which engages a
pin 15 at the lower end of an iron bar 16 that is carried by links 17 and is arranged
to form the armature of two electro magnets 18 and 19 between the poles of which
it is arranged to oscillate. The electro-magnet 18 serves when energised, to attract
the armature 16 and operate the mechanism just referred to in a direction to simul-
taneously move the main slides apart, and into the position shown in full lines in
Fig. 3, thereby uncovering the main feeding aperture 3. The electro-magnet 19
serves, when energized, to attract the armature and move the mechanism in the
opposite direction, and thereby simultaneously move the main slides together so as
to reduce the size of the feeding aperture to that shown by the dotted lines 3*
(Fig. 3) which represents the smaller aperture. To prevent tea passing between
the slides 4, 4 and the underside of the plate 2, the sides of the aperture 3 past
which the slides move, is provided with brushes or with material 4* (Fig. 34) such
as felt, arranged to bear against the upper sides of the said slides.
The smaller slides 5, 5* are moved in directions to close and open the smaller
feeding aperture 3* by electro magnets 18° and 19" respectively, that are actuated
through an arrangement of mechanism similar to that employed for operating the
main slides 4, 4 and the several parts of. which, corresponding to the parts herein-
before enumerated, are indicated by the addition of the letter a to the reference
figures used for such parts (see Figs. 3 and 4).
The cores of the electro magnets are secured to iron brackets 20, which
are fixed to a plate 21 carried by the plate 2. Near the bottom of the
hopper is a stirrer comprising arms 22 fixed to a rotary shaft 23 that is
supported, partly by a journal bearing 24, and partly by a pivot 25, and is
provided with fast and loose pulleys 26 and 27 respectively. 28 is a bar
arranged to slide in guides 29 and provided with arms 30, the whole constituting a
belt shifting device for a belt working alternately on the pulleys 26 and 27. 31 is
an insulated contact carried by a switch lever 32 by which it is capable of being
moved to and from a fixed insulated contact 33. The switch lever, which is
pivoted at 34, and passes between pins 28 and 28° on the belt shifting bar 28, is
provided with a handle 35 by which it can be moved to operate the belt shifter, and
to make and break the main circuit between the contacts 31 and 33 when starting
and stopping the machine as hereinafter described. The handle 35 is provided
with tappets or projections 36 and 36*, adapted to act against the adjacent lever
arms 7, 7 respectively and operate the same and connected mechanism in such a
manner as to close the main and smaller slides should either of these happen to be
in the open position immediately prior to moving the handle in the direction of
the arrow a (Fig. 3) to stop the machine.
The main weighing device comprises a scale beam 37 (hereinafter called the main
beam) carried by knife edge bearings 38 in standards 39 and carrying an adjustable
weight 40 by which it can be accurately set or balanced. The standards 39 are
fixed to a support 39 arranged to slide in guides upon a bed 39° carrying a
casing 39 within the upper part of which the hopper 1, plate 2 and attached parts
are located. Suspended from the front and rear ends of this beam by knife edge
bearings 41 41 are links or stanchions 42 and 43 respectively. These links or
stanchions are jointed by stays or guides 42 and 43* respectively to a fixed pin 44
(Figs. 8 and 9) arranged directly below the knife edge bearings 38, these stays or

page_text: guides forming what is known as "bottom work." The link or stanchion 42 carries
a plate 44* for supporting a weight 44" (Fig. 1) corresponding to that of the tea to
be weighed at each operation of the machine. The link or stanchion 43, which is
made of the peculiar form shown in order to adapt it to carry the parts herein-
after mentioned, serves to indirectly carry a series of scale pans 45. In the example!
shown there are four pans, the near one being removed in Fig. 1 in order to show
the mechanism behind. The scale pans, link 43 and other parts may in order to
obtain lightness be made of aluminium.
The scale pans are each fixed by means of a spoke or suitable support 46 to a
hub 47 mounted to revolve on a ball bearing 48 carried by a plate 48 which is 1
supported by the secondary weighing device. This device in the arrangement
shown, comprises a lever 49 (hereinafter called the secondary beam) pivoted at 50
and between the forked end portions 49" of which is pivoted the plate 48 which
for this purpose is formed with lugs or ears into which take pivot pins 49" carried
by the said forked portions 49.
This secondary weighing device may be loaded by a spring 51 which allows of a
gradual movement of the secondary beam as the weight accumulates in the scale
Or instead of using a spring, I may lengthen the inner arm of the secondary
beam 49 as indicated in dotted lines in Fig. 1, and provide it with a weight 51*
capable of endways adjustment on the lever arm to suit requirement.
pan.
Attached to the secondary beam are two platinum contact surfaces 52 and 53
which engage with two other contacts 54 and 55 respectively that are carried by but
insulated from the link 43. The contact surface 52 is held against the contact 54
by the action of the spring 51 or the weight 51 when the pan is empty. The
contact 53 is brought against the contact 55 when the weight of tea in one of the
pans is sufficient to overcome the action of the spring 51 or to lift the weight 51*
to a sufficient extent.
The secondary weighing device is only approximate in accuracy, and is used
simply to obtain the required electrical contacts for operating and controlling the
main slides 4, 4* as hereinafter explained. To facilitate the expeditious weighing
of large quantities of tea at each weighing operation, two or more pairs of large
slides may be used each operated and controlled by mechanism similar to that
herein before described for the one pair of large slides, an additional contact
adapted to engage with the secondary beam 49 being provided to open each
additional pair of large slides. These additional contacts should be made flexible
so as to allow the secondary beam to continue moving and make successively the
additional contacts required in each case. An arrangement for this purpose is
illustrated in side elevation in Fig. 14, wherein two additional contacts are shewn.
55 and 55 are the flexible contacts which are insulated from each other and from
the link 43, and act successively against the additional contacts 53 and 53 which
are adjustable and in electrical connection with the beam 49. The contacts 55*
and 55 are connected by suitable conductors to electro-magnetic mechanism similar
to that used in the case of the one pair of large slides herein before described. In
this way a number of feeding apertures of different sizes can be closed in succession
when predetermined portions of the weight of tea have entered the scale pan.
These said apertures would be simultaneously opened again when, after emptying
the pan the secondary beam is, by the action of the spring or weight again brought
against the contact viz. (54) which in the case of the single large aperture 3 served
to open such aperture.
The scale pans 45 are each fixed to the outer end 46" of one of the spokes 46
which is bent as shown so that the centre of gravity of each pan, together with its
load, is not in vertical alignment with the axis of the hub 47. By this means when
the series of pans are released, the loaded one will fall to that side of the axis of
the hub to which the bent end of the spoke carrying it projects, and will bring an
empty pan into position for use. By bending the outer ends of all the spokes in
the same way so that each, when uppermost, will point in the same direction, the
contents of each pan can be directed in succession into one common funnel 39ª

page_text: which directs the material into suitable receptacles placed below. By employing
say two pans, one leaning to one side and one to the other, the material can be
discharged alternately on either side, thus permitting, when the machine is going
very fast, the service of attendants on each side of the machine to place and take
away the receptacles into which the material is discharged.
To enable each pan 45 in turn to be held in position to receive tea from the
hopper above it and then to partly turn and discharge its contents, the hub 47 is
provided with a flange 55 formed with four equidistant recesses into one or other
of which a catch 56 is normally pressed by the action of a spring 57. The catch
is connected to the armature 59 of an electro-magnet 60 carried by the plate 48*
in the lower forked portion 48 of which the catch 56 is pivoted. 61 is a bar fixed
to the pivoted plate 48" and jointed to one end of a radius bar 62 the other end of
which is jointed at 62 to the link 43. By this construction the spokes 46 will rise
and fall in a vertical plane when the secondary beam 49 tilts in either direction.
The catch 56 holds the scale pans 45 stationary and in proper position while
each receives its load, but releases the pans and allows them to partly rotate when
it is moved out of the recess by the armature 59 being attracted when the circuit
of the electro-magnet 60 is completed by the tilting of the main beam with the
required weight. 63 is an adjustable screw contact carried by but insulated from
a plate 64 secured by arms 64" to the rear end of the main beam 37. 65 is an
insulated contact pillar upon which the contact 63 normally rests and supports the
rear end of the main beam in position. 66 is an adjustable contact carried by and
in electrical connection with the plate 64 and main beam 37. 67 is a movable
contact carried by a weighted spring 68 and in metallic connection with a cock
piece 69.
The several parts may conveniently be connected up in the manner indicated
diagrammatically in Fig. 13. In this figure 70 and 71 are terminals in electrical
connection with the poles of an electric generator. The terminal 70 is connected
by a conductor 72 to the main beam 37 which is electrically connected with the
secondary beam 49. The contact 54 is connected by a conductor 73 with the
winding of the electro magnets 18° 18 that serve to open the slides and which are
in series with each other and are connected with the other terminal 71. The
contact 55 is connected by a conductor 74 to the contact 63, and the contact
pillar 65 is connected by a conductor 75 with the winding of the electro-magnet 19
which serves to close the main slides and which is also connected with the
terminal 71. Or the contact 55 may be connected direct to the winding of the
electro magnet 19 by a conductor 74*, as indicated by dotted lines. The cock
piece 69 carrying the spring contact 67 is connected by a conductor 76 with one
end of the winding of the electro magnet 60 the other end of which is connected
by a conductor 76 with the winding of the electro-magnet 19" which serves to
close the small slides (or slide) and which is also connected to the terminal 71.
32 is the switch lever for making and breaking the electric circuit. 77 is a spring
push by means of which and an auxiliary conductor 76 the circuit of the winding
of the electro magnet 60 can be completed at will by way of the conductor 76 and
the winding of the electro magnet 19ª for the purpose of allowing the scale pans 45
to partly rotate and discharge any tea that may remain in any one of them after
the main circuit has been broken.
The action of the machine is as follows:--
Assuming the several slides to be closed and that the terminals 70, 71, are con-
nected to the poles of an electric generator then, upon closing the switch lever 32,
an electric current will flow from the terminal 70 to terminal 71 by way of the
conductor 72, main beam 37, secondary beam 49, contact 54 conductor 73 and the
windings of the electro maguets 18* 18 thereby energizing these magnets so that
they will attract their respective armatures and open both sets of slides. The
driving belt will be simultaneously moved from the loose pulley 27 to the fast
pulley 26 and the stirrer set in motion. Tea will then fall through the main
feeding aperture 3 into the uppermost scale pan 45 below and the secondary beam

page_text: will be caused thereby to gradually tilt against the action of the spring 51 or the
weight 51* so as to move away from the contact 54, breaking the circuit of the
electro-magnets 18 and 18, and finally bearing against the contact 55 when a
certain predetermined weight of tea, less than the total desired weight, has entered
the scale pan. The electric circuit will then be completed by way of the :
conductor 74, contact 63, contact pillar 65, and conductor 75, (or by the
conductor 74 74*) through the winding of the electro-magnet 19 which then acts
to close the main slides 4, 4" and main feeding aperture 3 but leaving the smaller
aperture 3* open through which a small stream of tea will continue to fall until
the exact weight of tea has entered the scale pan. When this takes place, the
main beam 37 will tilt and bring the contact 66 into electrical connection with the
contact 67 and cock piece 69, whereupon the electrical circuit will be completed
through conductor 72, beam 37, plate 64, contact 66 cock piece 69, conductor 76,
winding of electro-magnet 60, conductor 76, winding of electro-magnet 19" to
terminal 71 thereby actuating the smaller slide or slides, closing the smaller
aperture 3* and releasing the scale pans which then turn sufficiently to empty the
contents of the uppermost pan into the discharge hopper 394 and bring the next
pan into position for use. The secondary beam will then be moved back into its
original position by the spring 51 or the weight 51* and the electro-magnets 18", 18
will be again energized so as to again open all the slides, whereupon another
weighing operation will take place, the several operations taking place in an
automatic manner so long as the switch is closed. To stop the machine the switch
lever 32 is opened, the electrical circuit broken and the stirrer thrown out of
action. Should the slides be in the open position immediately before opening.the
switch, they will be closed by the action of the projections 36, 36ª on the handle 35
of the switch lever 32 as hereinbefore explained.
As will be obvious apparatus according to my invention can be constructed in
various forms without departing from the essential features thereof. Thus instead
of using two small slides 5, 51 in some cases prefer to use one (5) only as
illustrated in Fig. 15 which is a similar view to Fig. 3. In this arrangement the
adjacent ends of the main slides 4, 4 are straight so that when they come into
contact with each other they will completely close the main feeding aperture 3.
The small aperture 3* is in this case arranged at one side of the large aperture 3
so as to be practically unaffected by the main slides, and is controlled by the single
slide 5 the operating lever 7 of which can be actuated directly from the lower end
of the armature 16 by a link 7'.
Figs. 16 and 17 are respectively side and end elevations, and
Fig. 18 is a diagrammatic view illustrating an alternative arrangement by.which,
with the use of a relay a similar result to that hereinbefore described can be
obtained.
In this arrangement the plate 64 which is in connection with the main beam,
serves to directly carry the adjustable rigid contact screw 63 and the adjustable
screws 63* to which are attached flexible contacts 63". The contact 63 rests upon
the contact pillar 65 and supports the rear end of the beam as before. The
flexible contacts 63* which are in electrical connection with the rigid one 63,
serves to prevent, when the balance is very nearly arrived at, premature breaking
of the electrical connection between the pillar and the main beam on the part of
the rigid contact 63, due to the impact of the tea on the scale pan, or to the acci-
dental shaking of the machine. Any flexible contact, such as a spring, will
answer the purpose, but I consider it more advantageous to use one or more
platinum chains as shewn, the length of which is slightly greater than is necessary
to reach the contact pillar so that they will not be lifted clear of the latter by
slight oscillations of the beam due to vibrations, although the rigid one may be,
but will still continue in contact until the beam decidedly tilts with the right weight.
Such a chain is preferable to a spring, because it always breaks contact at exactly
the same position of the beam, it has less friction, and it does not tend to help the
beam to rise. 66* is an adjustable stop which together with the cock piece .69
"

page_text: serves to prevent undue tilting of the beam. Similar parts in Figs. 13 and 18 are
numbered alike.
The action of this modified construction of machine is as follows:-On closing
the switch 32 a current will flow from terminal 70 to terminal 71 by way of
conductor 72 to main beam 37, where it will divide part of the current passing to
terminal 71 by way of beam 37 secondary beam 49, contact 54, conductor 73 and
the windings of electro-magnets 18" and 18, thereby energizing these magnets so
that they will attract their respective armatures and open both sets of slides. The
remainder of the current which divided at the main beam 37 will proceed along
this beam to plate 64 and as the desired weight of tea will not yet have passed into
the uppermost pan 45 this end of the beam will be heavier and both the rigid
contact 63 and flexible contacts 63 will be in connection with the insulated
pillar 65. By means of these contacts the current will flow to pillar 65, con-
ductor 65, the winding of relay coils 80, conductor 65, back to terminal 71. The
relay coils 80 being thereby energized will attract the amature 81 thereby severing
the connection with contact stop 82.
When sufficient tea has fallen into the scale pan 45 to tilt the secondary beam 49
against the action of the spring 51 (or weight) far enough to bear against the
contact 55, a current will flow by way of conductor 74 and the winding of electro-
magnet 19 to terminal 71 thereby closing the main slides 4 and 4 and main
aperture 3 leaving the smaller opening 3* through which a small stream of tea will
continue to flow until the exact weight has entered the scale pan. When this takes
place the main beam 37 will tilt thereby breaking the contact existing between the
combined rigid and flexible contact 63 and 63 and the insulated pillar 65.
The coils of the relay being then no longer excited the armature 81 will, by the
action of its spring 83 fly back and make connection with the contact stop 82. A
current will now be able to flow by way of switch 32, conductor 84, contact 82,
relay armature 81, conductor 76, windings of electro-magnet 60, conductor 76.
winding of electro-magnet 19 back to terminal 71, thereby closing the small slide
or slides and releasing the scale pans which then turn sufficiently to empty the
contents of the uppermost pan into the discharge hopper 39ª and bring the next
pan into position for another weighing, when the machine will go through the same
operations as before in an automatic manner.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is :-
:-
1. A machine for weighing material of the kind hereinbefore referred to 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 the material is controlled
by another slide or slides operated by an electro magnetic device controlled by
the main weighing device substantially as hereinabove described.
2. A machine for weighing material of the kind herein referred to constructed
with a series of scale pans adapted to be brought in succession into a position to
receive material to be weighed, and means under the control of the main weighing
device for holding the said scale pans in position for use, the arrangement being
such that when a predetermined weight of material has entered one of the scale
pans, the series of pans will be released so that a fresh pan will be brought into
position for use substantially as herein described.
3. A machine of the kind referred to in Claim 1, constructed with scale pans
mounted to turn about a centre and normally held in position by an electro-
magnetic device the circuit of which is controlled by the main weighing device, the
arrangement being such that when a predetermined weight of material has entered
a scale pan the main weighing device will move and complete the circuit of the
electro-magnetic device which will then act to release the scale pans and allow them
B

page_text: to partially rotate so that the material will be discharged from the scale pan and a
fresh scale pan brought into position for use substantially as described.
4. My improved machine for weighing material of the kind referred to, con-
structed substantially as hereinbefore described with reference to and shown in
Figs 1 to 13 inclusive, or modified according to Fig. 14, or according to Fig. 15;
or according to Figs. 16, 17 and 18 of the drawings annexed.
Dated this 17th day of January 1802
GEO. H. DRIVER.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Applicants Agent.