Improvements in Mechanism applicable to Tea Weighing and other similar Machines.
Year: 1890

page_text: Date of Application, 1st Oct., 1890
Complete Specification Left, 1st July, 1891-Accepted, 1st Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in Mechanism applicable to Tea Weighing and other
similar Machines.
I, WILLIAM SNELGROVE, of the "Nest," Kings Norton, in the County of
Worcester, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to weighing machines intended to weigh out tea or similar
substances, and its object is to weigh specified portions of divided matter at a more
rapid rate and with greater accuracy than has been hitherto possible.
My invention comprises the following essentials:-A new mode of controlling by
electricity the doors or sluices which permit the tea to pass from a hopper into a
weighing hopper, which weighing hopper is suspended from the end of a counter-
poised beam, or steelyard; a mechanical feeder actuated by hand or power to feed
the tea or other divided matter from a main hopper to an intermediate hopper,
which feeder is so constructed that although rotated at a constant, or nearly
constant rate, the tea is fed from the main hopper at two or more speeds as
determined electrically in a manner hereinafter described; suitable contacts pre-
ferably of the spring type together with armatures, and electro-magnets and pawls
to convey from a source of electric current the necessary power to control the
actions of the weighing and feeding machines.
One mode of carrying my invention into effect as applied to a tea weighing
machine is as follows:-
:-
I arrange a larger hopper, hereinafter called the main hopper, to contain the
tea to be weighed out into separate parcels, and under this I place an intermediate
hopper; but between the two I arrange my feeding appliance. The feeding
appliance consists of a cylinder carried on a spindle and having projections on its
surface, and it fits loosely to the lower part of the main hopper; so that when it is
stationary no tea falls past it into the intermediate hopper but when the cylinder
is rotated by hand or power the projections carry the tea round and feed it into the
intermediate hopper at a specified rate. From the intermediate hopper the tea
falls by way of a passage controlled by a door or sluice to the open end of the
weighing hopper. The weighing hopper is suspended from a counterpoised beam
or steelyard, with the knife edges so placed, that the beam swings in unstable
equilibrium, that is, the centre of gravity of the weighing hopper with its charge,
and the counterpoise is above the centre of support of the knife edges; so that
immediately the weight of the counterpoise is very slightly exceeded the beam falls
rapidly. The electric current to control the rate of feed, and the doors or sluices
passes by way of the beam knife edges, or through a flexible conductor to the beam,
and thence by a spring contact to the necessary electro-magnets, and then to the
battery or other source of current. The spring contact at the poise end of the
beam is arranged that the current passes by way of the spring to an electro-magnet,
which controls the intermediate hopper door or sluice, and so long as the circuit
is complete the electro-magnet attracts an armature against the action of a spring,
and holds open the door or sluice. So long as enough of the weight of the counter-
poise acts to press home the spring contact, another contact is also made between
the lower part of the flat spring, when such a spring is adopted, and the upper part
of a second contact, from which wire leads to an electro-magnet controlling the
feed. So long as this electro-magnet is excited by the current which divides
through the two electro-magnets, its armature is held against the action of a spring,
and the fast feed continues in action. Immediately however that the weight of
tea fed into the weighing hopper becomes sufficient to allow the contact spring to

page_text: move the beam slightly against the counterpoise, then the spring rises and breaks
the circuit at the second contact; so that the current now passes wholly by the
spring and no part reaches the feed electro-magnet. A spring immediately pulls
off the armature, and a pawl engages the teeth of a ratchet wheel the effect of
which operation is to diminish the rate of feed. This is accomplished in the
following simple manner :-The rotating feed cylinder with pins or projections is
divided into two portions one of which is mounted upon a sleeve, carried on the
spindle, and this sleeve carries at its end the ratchet wheel, a spiral or other spring
forces the two portions together, and causes friction enough to make the whole
cylinder rotate when the spindle is rotated. When the pawl however falls into the
ratchet by the cessation of the electric current, the sleeve, and that portion of the
cylinder mounted on it is held stationary, so that only the portion mounted rigidly
on the spindle continues to rotate. The slow feed of tea is thus supplied auto-
matically to finish the weighing. The rapid feed fills in the charge of tea to the
weighing hopper rapidly till the required weight is nearly present and then the
slow feed adds enough to just turn the beam. When the beam falls the spring
contact is also interrupted and the spring on the armature controlling the door or
sluice on the intermediate hopper at once closes it, and so shuts off the tea. A
lever is applied to open a door or sluice in the lower part of the weighing hopper
to discharge its weighted contents into suitable packages or receptacles and I
sometimes apply a catch lever to hold the weighing hopper down, until it has
discharged its contents, and control this catch lever by the door or sluice in the
weighing hopper so connecting them, that the catch is not liberated till the door
or sluice is closed. This prevents the weighing hopper from rising while it is
discharging tea. When desired I also arrange additional mechanism to supply
packages automatically to the machine, fill them with weighed charging tea and take
them out of the machine.
Sometimes I obtain the electric current required by means of a small dynamo
machine actuated from the feed cylinder.
Dated this 30th day of September 1890.
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for Applicant.
COMPLETE SPECIFICATION.
Improvements in Mechanism applicable to Tea Weighing and other
similar Machines.
1, WILLIAM SNELGROVE, of the Nest, Kings Norton, in the County of
Worcester, Engineer, 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 :-
My invention relates to weighing machines intended to weigh out tea or similar
substances, and its object is to weigh specified portions of divided matter at a more
rapid rate and with greater accuracy than has hitherto been possible.
My invention comprises the following essentials :-A new mode of controlling by
electricity the doors or sluices which permit the tea. to pass from a hopper into a
weighing hopper which weighing hopper is suspended from the end of a counter-
poised beam or steelyard; a mechanical feeder actuated by hand or power to
feed the tea or other divided matter from a main hopper to an intermediate hopper,
which feeder is so constructed that although rotated at a constant or nearly
constant rate the tea is fed from the main hopper at two or more speeds as
determined electrically in a manner hereinafter described; suitable contacts pre-
ferably of the spring type together with armatures and electro magnets and pawls
to convey from a source of electric current the necessary power to control the
actions of the weighing and feeding machines.

page_text: Referring to the accompanying sheet of drawings illustrating one mode of
carrying my invention into effect as applied to a tea weighing machine,
Figure 1 is part in section, part elevation,
Figure 2 is a transverse section through the feeder part of the machine ;
Figure 3 is an external elevation corresponding to Figure 1 showing the electrical
device for changing the rate of feed;
Figure 4 illustrates the lower position of the weighing hopper and
Figure 5 is an elevation of the weigh beam and electrical contacts on a larger
scale.
I arrange a large hopper A hereinafter called the main hopper to contain the
tea to be weighed out into separate parcels, and under this I place an intermediate
hopper F, but between the two I arrange my feeding appliance. The feeding
appliance consists of a cylinder B, C carried on a spindle and having projections
as B3, C' on its surface, and it fits loosely to the lower part of the main hopper A
so that when it is stationary no tea falls past it into the intermediate hopper but
when the cylinder is rotated by hand or power the projections carry the tea round
and feed it into the intermediate hopper at a specified rate. From the intermediate
hopper the tea falls by way of a passage controlled by a door or sluice F' to the
open end of the weighing hopper H. The weighing hopper H is suspended from
a counterpoised beam or steelyard H with the knife edges so placed that the beam
swings in unstable equilibrium, that is, the centre of gravity of the weighing hopper
loaded with its charge and the counterpoise as H2 is above the centre of support of
the knife edges so that immediately the weight of the counterpoise H² is very
slightly exceeded the beam falls rapidly. The electric current to control the rate
of feed and the movement of the doors or sluices passes by way of the beam knife
edges or through a flexible conductor to the beam and thence by a spring contact
to the necessary electro magnets and then to the battery or other source of current.
The spring contact at the poise end of the beam H' is arranged that the current
passes by way of the spring to an electro magnet G which controls the intermediate
hopper door or sluice F¹ and so long as the circuit is complete the electro magnet G
attracts an armature on the lever against the action of a spring and holds open
the door or sluice F¹. The door or sluice F¹ is attached to the lever F2 which
pivots from the point F³. So long as enough of the weight of the counterpoise H
acts to press home the spring contact against the contact pillar H', another
contact is also made with the second contact pillar H³. From this second contact
pillar H³ a wire E³ leads to an electro magnet E controlling the feed, and a wire E
leads from E to the battery I. So long as this electro magnet E is excited by the
current which divides through the two electro magnets E and G its armature E¹
is held against the action of a spring and the fast feed continues in action.
Immediately however, that the weight of tea fed into the weighing hopper H
becomes sufficient to allow the contact spring to move the beam H' slightly
against the counterpoise then the spring breaks the circuit at the second contact ³, H³
so that the current now passes wholly by the spring and no part reaches the feed
electro magnet E. A spring immediately pulls off the armature E' and a pawl
upon the armature engages the teeth of a ratchet wheel B2 the effect of which
operation is to diminish the rate of feed. This is accomplished in the following
simple manner :-The rotating feed cylinder B, C with pins or projections B³, C' is
divided into two portions B and C one of which B is mounted upon a sleeve B
carried on the spindle D and this sleeve carries at its end the ratchet wheel B2, a spiral
or other spring or end collars without a spring forces the two portions together and
causes friction enough to make the whole cylinder rotate when the spindle is rotated.
When the armature pawl E' however, falls into the ratchet B32 by the cessation of the
electric current, the sleeve B¹and that portion of the cylinder mounted on it that is B
is held stationary so that only the portion mounted rigidly on the spindle D which
is C continues to rotate. The slow feed of tea is thus supplied automatically to finish
the weighing. The rapid feed caused by the rotation of the whole cylinder fills in
the charge of tea to the weighing hopper rapidly till the required weight is nearly

page_text: present and then the slow feed caused by the rotation of the part C alone adds
enough to just turn the beam H¹. When the beam falls the spring contact h, H
is also interrupted and the spring on the armature lever F2 controlling the door
or sluice F on the intermediate hopper F at once closes it and so shuts off
the tea.
The electric current to operate the electro magnet G passes from the battery I
by the wire G2 returning by the wire G', contact pillar H4, spring contact h,
beam H through the knife edges to the pillar and wire G³ connected to the other
battery screw. The pillar H³ is insulated from H and when the contact, H³ is
made part of the current from I passes through the electro magnet E by the
wire E returning by wire E³ and contact h', H³ thence through H¹ to G³ as before.
When both contacts are made the current thus divides and excites both electro
magnets and when the spring h lifts the poise end of the beam the contact h', H³ is
broken and the armature pawl E falls into the ratchet wheel as described.
A lever is applied to open a door or sluice in the lower part of the weighing
hopper to discharge its weighted contents into suitable packages or receptacles and
I sometimes apply a catch lever as to hold the weighing hopper H down until it
has discharged its contents and control this catch lever by the door or sluice in
the weighing hopper so connecting them that the catch is not liberated till the
door or sluice is closed. This prevents the weighing hopper from rising while it is
discharging tea. The linkage a, b, c, d, e may be conveniently used to control one
door or preferably two doors, K, K' which close the bottom of the hopper. By
this linkage the doors K1, K2 are held closed by the catch lever K so long as the
weighing hopper is up and receiving tea as in Figure 1. When it overbalances and
falls down to the position shown in Figure 4 the lever K strikes the stop L
Figures 1 and 4 and liberating the lever a the linkage allows the weight of the tea
to open the doors as at K', K2, Figure 4. So soon as the tea has discharged the
doors close by the counter weight and assume the position indicated in thick dotted
lines at k¹, Figure 4 and the lever e strikes the stop for the lever knocking it
off the catch and allowing the beam H' to rise. Another weighing then begins as
already described.
Sometimes I obtain the electric current required by means of a small dynamo
machine actuated from the feed cylinder.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
(1) In a machine for weighing tea or like substances in a state of division the
use of a feed cylinder rotated by hand or power and controlled electrically so that
a part only of the cylinder is permitted to rotate when the beam rises and a slow
feed is required substantially as and for the purposes herein before described and
illustrated in the accompanying drawings.
(2) A tea or like weighing machine comprising a feed cylinder as B, C, controlled
by a ratchet wheel as B³, an electro magnet and armature as E, E¹ a sluice as F¹
controlled by electric magnet G and lever F2 and contacts as h, H* and h¹, H³
substantially as and for the purposes herein before described and illustrated in the
accompanying drawings.
(3) A tea or like weighing machine constructed and arranged and acting
substantially as hereinbefore described and illustrated in the accompanying
drawings.
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicant.