Year: 1887

page_text: Date of Application, 10th Nov., 1887
Complete Specification Left, 3rd Aug., 1888
Complete Specification Accepted, 14th Sept., 1888
I, RICHARD CLARKE, of Vulcan Works, 44, Shadwell Street, Birmingham, Warwick
shire, Engineer and Machinist, do hereby declare the nature of this invention to be as
follows:
$6
This invention has reference to those presses for forming hollow articles from sheet
metal blanks in which what is known as a pressure plate" or "pressure collar” is
employed to operate in combination with the ram or plunger, the object of the pressure
plate being to hold down the blank on to the bottom die and prevent its puckering
while the ram or plunger descends through the pressure plate and forces the central
part of the blank into the bottom die by drawing it from between the pressure plate
and the bottom die.
The object of my invention is to provide improved means of operating the pressure
plate so as to dispense with the use of separate eccentrics or cams for that purpose as
heretofore ordinarily employed.
I will describe my invention as applied to a press in which the ram moves to and
fro in a vertical plane.
For the purposes of my invention the pressure plate is free to slide upon the ram or
plunger and projecting from the side of the latter and at equal distances apart are
two or more pins, preferably four in number (or a single pin may be used) which
take into corresponding slots in the pressure plate. These slots are similar to each
other the lower part of each being vertical, that is parallel with the axis of the ram,
and the upper part being inclined for the purpose hereinafter explained. Projecting
outwardly from the periphery of the pressure plate are two or more lugs equidistant
When the pressure
from each other the upper surfaces of which are slightly inclined.
plate is in position on the bottom die ready for the ram to descend these lugs take
under corresponding inclined projecting parts or dogs formed on or fixed to the bed
of the press which prevent the collar rising. These projecting dogs are preferably

page_text: made loose from the bed of the press and each provided with a vertical screw threaded
shank which passes through the bed of the press and has a lock nut above and a lock
nut below the bed of the press, by means of which the height of the inclined projecting
parts can be varied so as to increase or diminish the pressure of the pressure plate and
to suit different thicknesses of blanks.
The operation of the parts above described is as follows:-When the ram is raised
ready for the insertion of a blank on the bottom die the pressure plate is raised also
by the pin or pins on the ram coming into contact with the top of the said slot or
slots. The ram and pressure plate descend together until the latter rests upon the
blank on the bottom die when the ram descends alone and in so doing the said pins on
the ram in travelling down the inclined part or parts of the slots in the pressure plate
or collar cause the latter to turn round its axis through a small angle thereby forcing
the projecting lugs of the pressure plate under the corresponding projecting dogs and
holding the blank firmly between the pressure plate and the bottom die. When the
pins have travelled into the vertical part of the slots the axial motion of the pressure
plate ceases and the ram travels on to the bottom of its stroke. When the ram in
rising has moved so far that its pins again engage with the inclined parts of the slots
they cause the pressure plate to turn round far enough to disengage the lugs on the
pressure plate from the dogs when the pressure plate will be free to rise with the ram.
In a modification of my invention the pressure plate has no axial motion but only
moves up and down and it is held and pressed on to the blank on the bottom die by
two or more inclined locking pieces which are suitably supported from the bed or fixed
part of the press. These inclined locking pieces are forced back by the pressure plate
in descending and when the pressure plate has arrived on the bottom die a projecting
part or parts of the ram comes or come into contact with the inclined pieces and
forces them forward on to the lugs of the pressure plate and so hold it firmly on the
bottom die. When the ram has risen through a certain space the locking pieces are
free to be pushed back by the pressure plate in ascending.
Dated this 8th day of Novemba 1007
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.

page_text: Improvements in Presses for Forming Hollow Articles from Sheet
Metal.
1, RICHARD CLARKE, of Vulcan Works, 44, Shadwell Street, Birmingham, Warwick-
shire, Engineer and Machinist, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
This invention has reference to those presses for forming hollow articles from sheet
metal blanks in which what is known as a "pressure plate" or
pressure collar" is
employed to operate in combination with the ram or plunger the object of the pressure
plate being to hold down the blank on to the bottom die and prevent its puckering
while the ram or plunger descends through the pressure plate and forces the central
part of the blank into the bottom die by drawing it from between the pressure plate
and the bottom die.
The object of my invention is to provide improved means of operating the pressure
plate so as to dispense with the use of separate eccentrics or cams for that purpose as
heretofore ordinarily employed.
I will describe my invention as applied to a press in which the ram moves to and
fro in a vertical plane.
For the purposes of my invention the pressure plate is free to slide upon the ram or
plunger and projecting from the side of the latter and at equal distances apart are
two or more pins, preferably four in number (or a single pin may be used) which
take into corresponding slots in the pressure plate. These slots are similar to each
other the lower part of each being vertical, that is parallel with the axis of the ram,
and the upper part being inclined for the purpose hereinafter explained. Projecting
outwardly from the periphery of the pressure plate are two or more lugs equidistant
from each other the upper surfaces of which are slightly inclined. When the pressure
plate is in position on the bottom die ready for the ram to descend these lugs take
under corresponding inclined projecting parts or dogs formed on or tixed to the bed
of the press which prevent the collar rising. These projecting dogs are preferably
nade loose from the bed of the press and each provided with a vertical screw threaded
shank which passes through the bed of the press and has a lock nut above and a lock
nut below the bed of the press by means of which the height of the inclined projecting
parts can be varied so as to increase or diminish the pressure of the pressure plate
and to suit different thicknesses of blanks.
The operation of the parts above described is as follows:-When the ram is raised
ready for the insertion of a blank on the bottom die, the pressure plate is raised also
by the pin or pins on the ram coming into contact with the top of the said slot or
The rain and pressure plate descend together until the latter rests upon the
slots.

page_text: blank on the bottom die when the ram descends alone and in so doing the said pins on
the ram in travelling down the inclined part or parts of the slots in the pressure plate
or collar cause the latter to turn round its axis through a small angle thereby forcing
the projecting lugs of the pressure plate under the corresponding projecting dogs and
holding the blank firmly between the pressure plate and the bottom die. When the
pins have travelled into the vertical part of the slots the axial motion of the pressure
plate ceases and the ram travels on to the bottom of its stroke. When the ram in
rising has moved so far that its pins again engage with the inclined parts of the slots
they cause the pressure plate to turn round far enough to disengage the lugs on the
pressure plate from the dogs when the pressure plate will be free to rise with the ram.
On the accompanying drawing Fig. 1 represents in front elevation and Fig. 2 in
sectional plan a ram with pressure plate or collar and part of the press base with
adjustable dogs constructed according to my invention the ram and pressure plate
being in their highest position; Fig. 3 is a sectional elevation of the same on the
line XX of Fig. 2; Fig. 4 shews the same parts as Fig. 3 with the pressure plate held
down by the dogs and Fig. 5 is a sectional plan of the same.
The same letters of reference indicate the same parts in all the Figures.
a is the ram or plunger (only the lower part of which is shewn) which is caused to
move up and down in guides by a crank or eccentric or other means as usual. bis
the pressure plate or collar free to slide on the ram a and carried by the four pins c
projecting from the ram a and taking into the slots d. The lower part of each of
which is vertical and the upper part inclined. The lugs formed on the lower part of
the pressure plate are marked e.
The dogs are by preference four in number and are marked f their screw threaded
shanks passing through holes in the base g of the press and capable of vertical adjust-
ment by the nuts h and i above and below the base. The lower inner part or collar j
of the pressure plate is made removable so that it can be changed to suit the size or
kind of blank required to be operated upon by unscrewing the four screws k which
hold the collar j in the pressure plate b.
In order to illustrate the operation of the parts I have shewn a lower part a² to the
ram, a collar and a bed or bottom die suitable for raising hemispherical vessels
from circular blanks but it is to be understood that any raising or drawing through
dies or tools can be used with my invention. The parts operate as follows:-When
the ram a is raised (see Figs. 1, 2 and 3) ready for the insertion of a blank m on the
bottom die l, the pressure plate with its collar j is raised also by the pins c coming
into contact with the top of the slots d. The ram a and pressure plate & descend
together until the latter rests upon the blank m on the bottom die l when the ram
descends alone (see Figs. 4 and 5) and in so doing the pins c on the ram in travelling
down the inclined parts of the slots d cause the pressure plate to turn round its axis
through a small angle thereby forcing the projecting lugs e under the corresponding
projecting dogs and holding the blank m firmly between the pressure plate or collar j
and the bottom die Z. When the pins c have travelled into the vertical part of the
slots & the axial motion of the pressure plate ceases and the ram a travels on to the
bottom of its stroke. When the ram a in rising has moved so far that its pins c again
engage with the inclined parts of the slots d they cause the pressure plate to turn
round far enough to disengage the lugs e on the pressure plate 6 from the dogs when
the pressure plate will be free to rise with the ram.
I wish it to be understood that I do not limit myself to the precise details herein
described and illustrated by the accompanying drawing as the same may be varied
without departing from the nature of my invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1st. In presses for forming hollow articles from sheet metal the combination with
the central ram or plunger, of a pressure plate or collar carried thereby and through
which the ram or plunger moves, which pressure plate is by the downward motion of

page_text: the ram or plunger caused to turn axially and engage with fixed parts so as to be
automatically clamped on the bottom die, and by the upward motion of the ram the
pressure plate is caused to turn in the opposite direction so as to be automatically
released from the bottom die and to rise with the said ram for the purposes and
substantially as set forth.
2nd. In a press for forming hollow articles from sheet metal the combination with
the central ram or plunger a, of the pressure plate b, the studs c, and the adjustable
dogs f, these parts being constructed and arranged to operate substantially as herein-
before described and illustrated by the accompanying drawing.
Dated the 1st day of August 1888
RICHARD CLARKE.