Improvements in Moulding Presses.
Year: 1898

page_text: Date of Application, 19th Jan.,
1898
Complete Specification Left, 18th Oct., 1898-Accepted, 10th Dec., 1898
Improvements in Moulding Presses.
We, WILLIAM RALPH DODD, of Oakdene, Bush Hill Park, Enfield,
Pharmaceutical Chemist, and HENRY ALFRED EDWARD SMITH, of 43, Hatherley
"Road, Hoe Street, Walthamstow, Engineer, do hereby declare the nature of this
invention to be as follows:-
The chief object of this invention is to provide a simple and effective press for
moulding or compressing drugs, in a state of powder, into pellets, tablets, lozenges,
or such other like form as may be desired; but the press is also applicable for
moulding or compressing other goods, such as soap tablets, etc., and the invention
consists more particularly in the means employed for adjusting the position, and
for causing the movement of the lower plunger, but the invention also consists in
the general construction of the press.
In carrying out this invention, a reciprocating hopper is employed, the outlet of
which slides on a faced table backwards and forwards over a die, into which the
contents of the hopper fall. The hopper is carried by a slide which is operated
through a series of levers by the compressing plunger. This plunger is carried
by a cross bar which works in guides, and is operated by suitably-mounted
excentrics connected with the cross-bar by straps and rods, or in any other
convenient manner.
The die is let into the table, and is supported by a fixed cross-head of the frame
of the press.
Into the die projects the lower plunger, the height of which in the die is adjusted
according to the desired thickness of the pellet, tablet, or lozenge, to be made.
This lower plunger forms, so to speak, an anvil to receive the blow of the top
plunger, but it also has to rise, to drive the formed pellet or lozenge out of the
die, so that it may be pushed away by the advancing hopper to a shoot, which
conveys it to a suitable receiver.
This lower plunger is carried and operated in a manner which will now be
described.
In the cross-head is formed a threaded hole to receive a threaded sleeve, which
is fixed in any given position by a lock-nut.
This sleeve receives a rod with an enlarged head, which fits a recess formed in
the sleeve, and the plunger is inserted in this head.
The bottom of the recess forms the abutment for the anvil, and the head has a
feather which fits a notch in the sleeve, and prevents the head from turning
irrespective of the sleeve.
The lower end of the rod is threaded, and passes through a nut contained in a
casing attached to a rectangular frame, in which tappet cams on a cam shaft
work. The nut is prevented from turning in the casing by a feather, and a cap
or cover with overhanging shoulders is provided for the casing. Into the cover
projects a sleeve with a flanged end, and this sleeve is screwed on the rod, and
locked with a lock nut.

page_text: To lower the plunger, the upper sleeve is screwed down the requisite distance.
This turns the rod in the nut, which is thus raised on the rod, so as to keep the
nut up against the shoulder of its casing, to provide for the return of the plunger,
after it has been raised, to push the pellet out of the die.
The lifting must, however, be constant, and therefore the flanged sleeve, or
lifting nut, as it may be called, which enters the cover of the casing, is screwed
down, so that the lift shall commence earlier.
Of the tappet cams, one lifts and the other lowers, both working in connection
with the rectangular frame, which has guide rods to keep it in position.
T
101
1000
NEWTON & SON,
Agents for the Applicants.
Improvements in Moulding Presses.
We, WILLIAM RALPH DODD, of Oakdene, Bush Hill Park, Eufield, Pharmaceutical
Chemist, and HENRY ALFRED EDWARD SMITH, of 43, Hatherley Road, Hoe Steeet,
Walthamstow, 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 :—
The chief object of this invention is to provide a simple and efficient press for
moulding or compressing drugs in a state of powder, into pellets, tablets, lozenges,
or other like forms.
.
In the accompanying drawings,
Figure 1 is a front elevation, and
Figure 2 a side elevation, partly in section, of the improved press.
A. A are standards supporting a casting or frame B, from which extend, upwardly,
side pieces or guides C. The frame B carries bearings for the main driving shaft D,
and also for a cam shaft E, and the side pieces C are connected together by the
cross bar F, and also carry a table G.
The side pieces C are provided with guides C¹ for a cross-head H, which carries
the striking or compressing plunger I. This cross-head is operated by means of
excentrics J, the straps of which are connected by rods K with the cross-head H.
The cam shaft E is driven by spur gearing, as shewn, or in any other convenient
manner.
A vertical threaded hole is formed in the cross-head H, to receive a screw I,
which carries the plunger I, and this screw is locked in position by the lock nut L'.
The plunger can thus be raised and lowered, as required, to give less or more
pressure to the substance to be moulded.
The table G is faced, and has a slot G¹, a die hole, and a discharge opening G².
Mounted on the table is a slide G³, which carries a hopper M, in which is placed
the pulverized substance intended to be moulded. The bottom of the hopper is
faced with a countersunk ring of wash-leather, which surrounds the discharge
opening, as shewn in Figure 3, which represents, on an enlarged scale, an inverted
plan view of the hopper. This hopper slides upon the table, the surface of which
is faced or polished to receive it. A traverse motion is communicated from the
cross-head H to the hopper by a series of rods and levers G*, connected to the
slide G³, and to an arm H¹ on the cross-head H.
O is the moulding die, which is inserted in the table G, and rests on a hollow
block P carried by the cross bar F.
The hopper M reciprocates over the die O, which is flush with the top of the

page_text: table G, and, at each forward movement, the die is filled with powder, the back-
ward movement of the hopper serving to remove the superfluous powder, so that
the exact amount required is left in the die.
The bottom of the die is formed by a plunger, which may be called the dio
plunger Q, and the height of this plunger is adjusted according to requirements.
The office of this plunger Q is not only to form the bottom of the die, and also the
anvil to receive the blow of the compressing plunger I, but it has also to rise, to
push the moulded pellet out of the die, and into the path of the advancing
hopper, which pushes it over the opening G2, to be discharged from the press.
The die plunger Q is carried and operated as will be now described. In the fixed
cross bar F is formed a vertical threaded hole to receive an externally threaded
sleeve R, which can be locked in any position by the lock nut R. Through the
sleeve passes a rod S, having an enlarged head S¹, which serves as the plunger
holder. This head fits into a recess formed in the end of the sleeve R to receive it,
and is prevented from turning, irrespective of the sleeve, by means of a feather, or
in any other convenient manner.
The rod S is threaded at its lower end, and passes through a nut T, which is con-
tained in a cylindrical casing U forming part of a rectangular frame V. The nut is
free to rise and descend in this case, but is prevented from turning by a feather or
otherwise. The casing U is closed by a perforated cover U¹, which has a shoulder
that overlies the nut T, and against which the nnt normally bears. The end of the
rod is turned down to form a steadying pin, which works in a hole in the bottom of
the casing. Upon the rod S, above the cover U¹, is what may be termed a lifting
nut W, which consists of a flanged sleeve and a lock nut. The sleeve portion enters
the cover U¹.
The frame V consists of top and bottom plates or bars connected together by
bolts and nuts, and it may have, at bottom, two guides V₁, which enter guide holes
in a plate B' secured to the casting B.
This frame spans the cam shaft, and is operated by tappet cams E1 E2 keyed
thereon. The tappet cam E acts to lift the frame, by striking against the top bar,
and the tappet cam E2 to lower the frame, for which purpose it is arranged so as to
strike on a lateral projection V2 on the bottom bar.
The operation of the machine is as follows:-Both plungers I and Q being
properly adjusted to ensure the requisite supply of material to the dio, and the
requisite pressure needed for the moulding operation, the press is started. The
cross-head H is raised by the excentrics J, and the hopper M is advanced to deliver
a charge to the die O. The die being thus filled with powder, the hopper retires,
cleaning, by means of its countersunk soft facing ring, the top of the die.
The plunger I now descends, compressing the powder in the die, the shoulder of
the die holder S resting on the bottom of its recess, thus supporting the plunger Q
while the blow is being struck.
The plunger I having, by its descent, moulded the pellet, now retires, and the
plunger Q follows its upward movement, thereby lifting the pellet clear of the die.
The hopper now again advances, pushing the pellet over the opening G² onto a
shute, down which it falls into the receptacle N. The plunger Q meanwhile retires,
and leaves the die free to receive a fresh supply of powder, after which the moulding
operation proceeds as before.
The movement of the plunger Q is effected as follows:-The cam E, in its rota-
tion, strikes the top plate of the frame V, and raises it, and with it the casing U
with its cover U¹. During its movement, the cover strikes against the lifting nut W,
and raises the rod S, and with it the plunger Q, so as to push the pellet out of the
die, as above explained.
The cam E is formed so as to cause the plunger to dwell in its raised position,
while the pellet is knocked away by the hopper M when the cam E2 comes into
operation, and, by striking on the projection V2 of the frame, draws down the
frame V, and with it the plunger Q, through the shoulder in the cover coming into
contact with the nut T.

page_text: The amount of compression to be given to the powder under treatment will be
regulated by screwing the die carrier L up or down in the cross-head H.
The thickness of the pellet is determined by adjustably raising or lowering the
die plunger Q, so as to leave a greater or less depth of chamber in the die. As,
however, the plunger Q must always rise to the same height, in order to push the
moulded pellet out clear of the die, and the size of the frame V and its cams is
constant, the adjustment must be provided for elsewhere, and the means shewn in
connection with the rod S have been adopted, to effect this object.
Suppose it is desired to lower the plunger Q for the purpose of increasing the
charge in the die, the sleeve R is screwed down, and, by reason of the feather on
the head, the rod S is also rotated in the nut T. The nut T is thus, in effect, raised
on the rod, and remains normally in contact with the shoulder of the cover. The
downward travel of the plunger is thus provided for.
But the lifting nut W also turns with the rod, and as the rod is lowered, so also
is the lifting nut. Thus, the cover U¹ comes into contact with the nut at an earlier
moment, and causes the plunger to travel the greater distance, though always to
the same height.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1. In a press for moulding pellets, tablets, and like articles, fitted with a traversing
feed hopper, a reciprocating plunger for condensing the material under treatment,
carried by a cross-head, which receives, through connecting rods, an up and down
motion from a pair of excentrics mounted on a cam shaft, and a second plunger,
forming the bottom of the die, and actuated to discharge the moulded articles from
the die by means of a reciprocating cylindrical casing forming part of a rectangular
frame, which embraces a pair of cams on the cam shaft, and imparts, through their
rotation, a rising and falling tappet action to that plunger, for the purpose above
set forth.
2. In a press for moulding pellets and tablets, in combination with a traversing
faced hopper for charging the die, and delivering the moulded articles from the
press, a vertically moving cross-head for actuating the same through the intervention
of a rock-shaft, one arm of which is linked to the hopper, and the other arm to the
cross-head, as above set forth.
3. In a pellet or tablet moulding press, the means above described for regulating
the depth of the moulding die, and securing the uniform rise of the lower plunger,
to discharge the moulded article, irrespective of the adjustment which regulates the
receiving capacity of the moulding die, such means consisting of an externally
threaded sleeve R, screwed into a fixed cross bar F of the frame, and recessed to
receive the plunger carrier; a cam-actuated frame V, to which is affixed a cylindrical
casing U, closed by a cover U¹, through which projects the rod S, fitted to a screw
nut T in the casing, and working on a feather, the rod S carrying also a flanged
lifting nut W, all as shewn and described.
Dated this 13th day of October 1898.