Improvements in Presses for Drawing or Stamping Sheet Metal.
Year: 1896

page_text: Date of Application, 16th June, 1896
La OLL
2002
Accented
0th May
4807
PROVISIONAL SPECIFICATION.
Improvements in Presses for Drawing or Stamping Sheet Metal.
I, PER FREDERICK HOLMGREN of No. 31 Vanderbilt Avenue, in the City of Brooklyn,
in the County of Kings and State of New York, United States of America, Machinist,
do hereby declare the nature of this invention to be as follows:-
My invention relates essentially to what are known in the art as drawing
presses used for drawing or stamping sheet metal in forming pans and other sheet
metal vessels, and employing a blank holder, which is made to advance upon the
sheet to be drawn and clamp the sheet on the face of the stationary die with suitable
pressure to prevent the sheet from buckling while a movable die comes later against
the middle portion of the blank through a central aperture of the holder, and draws it
into the bed die to shape the pan or other vessel, the movable die having constant
reciprocating motion imparted to it by a connecting rod and crank-shaft or other
equivalent means.
For so moving the blank holder and causing it to dwell and thus hold the blank
for being drawn smoothly from between it and the bed die, I employ a rocking crank-
shaft with a connecting rod coupling the crank-wrist either directly or indirectly
with the blank holder for actuating it, said connecting rod having a knuckle joint
between its extremities allowing it to articulate in one direction, but preventing it
from articulating in the reverse direction, the distance of the pivot of this joint from
the wrist pin centre being the same as the distance between the said wrist pin centre
and the axis of the rock shaft, and the said pivot is made to project in the form of a
stud from one or both sides of the connecting rod, and the crank hub is suitably
slotted to the axis of the rock-shaft for said stud or studs to enter said slots and lodge
in said axis when the crank passes the line in which the plane of the crank and the
line of the connecting rod coincide, where they rest while the crank continues to and
returns from the end of its stroke, and during that time hold the blank holder at rest
on the blank.
During the rest of the reverse movement of the crank, and its return to the centre
line again the connecting rod having assumed a straight line and being so maintained,
causes the retreat and advance of the blank holder preparatory to the next operation,
the pan being removed and a new blank inserted in the meantime. The connecting
rod may be connected directly to the blank holder in any approved way, or to one
arm of an intermediate bell-crank, the other arm or two arms being connected to the
blank holder, and various other ways of making this connection may be employed.
For some cases I contemplate two of these rock-shafts and such a knuckle jointed
connecting rod to each shaft and connected to the blank holder at opposite sides
respectively in a way whereby lateral thrusts on the blank holder will be counter-
balanced.
I also contemplate the application of the improvement in a hand press in which the
rock-shaft may be used both for working the blank holder and the movable drawing
die, and finally it will be seen that the jointed connecting rod and the described crank
for working it may be utilized for intermittent feeding nechanism for feeding blanks
in this class of metal working machines the connecting rod being attached to a
reciprocating feed slide instead of the blank holder.
Daind the 16th day of Lunn 1806
PHILIP M. JUSTICE,
Chartered Patent Agent, London,
For the Applicant.

page_text: Improvements in Presses for Drawing or Stamping Sheet Metal.
I, PER FREDERICK HOLMGREN of No. 31 Vanderbilt Avenue, in the City of Brooklyn,
in the County of Kings and State of New York, United States of America, Machinist,
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 essentially to what are known in the art as drawing
presses used for drawing or stamping sheet metal in forming pans and other sheet
metal vessels, and employing a blank holder, which is made to advance upon the
sheet to be drawn and clamp the sheet on the face of the stationary die with suitable
pressure to prevent the sheet from buckling while a movable die comes later against
the middle portion of the blank through a central aperture of the holder, and draws it
into the bed die to shape the pan or other vessel, the movable die having constant
reciprocating motion imparted to it by a connecting rod and crank-shaft or other
equivalent means, as hereinafter described reference being made to the accompanying
drawings in which:
Fig. 1, is a side elevation of my improved drawing press.
Fig. 14, is a side elevation with part of the housing detached.
Fig. 2, is a front elevation.
Fig. 2, is a sectional elevation on line y-y Figs. 2 & 3.
Fig. 3, is a top or plan view.
Fig. 4, is a side elevation of the rock-shaft for working the blank holder.
Fig. 5, is a transverse section of the said rock shaft on the line -. Fig. 4.
Fig. 6, is a side elevation of the jointed connecting rod by which motion is trans-
mitted from the rock-shaft to the blank holder, and the dwell of the blank holder is
effected, with dotted! lines indicating the operations.
Fig. 7, is a plan view of the said jointed connecting rod.
Fig. 8, is a top view of a bell crank by which said jointed connecting rod is coupled
with the blank holder.
Fig. 9. is a side elevation of said bell crank.
Fig. 10, is a top view of the blank holder and drawing punch.
Fig. 11, is a sectional elevation of the blank holder and drawing punch on the
line y-y of Fig. 3.
Fig. 12, is a sectional elevation of the blank holder and punch on the line -,
of Fig. 11.
Fig. 13, is a side elevation of duplex apparatus for actuating the blank holder
better adapted for large presses.
Fig. 14, is a side elevation of apparatus illustrating the application of the blank
holder actuating mechanism for an intermittent feeder suitable for stamping
presses.
Fig. 15, is an elevation of a drawing press having my improved blank holder
actuating apparatus and being organised so that both the blank holder and the
drawing punch are operated by the rock shaft which is an economical feature of
the improvement.
Fig. 16, is a front elevation of the apparatus of Fig. 15.
Fig. 17, is a sectional elevation of the apparatus represented in Figs. 15 & 16, the
section being taken transversely to the crank-shaft, at the middle or thereabout of the
front view in Fig. 16.
Fig. 18, is a front view of part of the machine represented in side view in Fig. 13,
with some parts in section, and
Fig. 19, is a front elevation of the apparatus of Fig. 14, with a part in section.

page_text: The main shaft a, to which the power is applied by a pulley, is coupled by a rod c,
and cranks d-e, to the rock-shalt / parallel to shaft a, but lower and back of the
vertical plane of the driving shaft, in which the blank holder g, and the drawing
punch are located, but the rock-shaft may have any other approved means of
operating it, as the lever in Figs. 15, 16 and 17. This rock-shaft has a crank i in the
central plane y-y of the machine from which motion is transmitted to the blank
holder by the knuckle-jointed connecting rod j-k, bell-crank 1, and the links m;
the rock-shaft may however be placed higher or in any suitable location.
g
This connecting rod composed of the said two parts j-k is coupled by a knuckle
joint allowing it to articulate in one direction but positively limiting it against flexure
in the opposite direction. The pivot n of this joint projects at one or both ends beyond
the sides of the fork o, of the connecting rod and the crank i has a channel or
channels p admitting sait projections to the axis of the rock-shaft where they lodge
and then serve as the pivot of part of the connecting rod when in the course of the
down movement of the blank holder the wrist pin q, said axis, and the pivot t, of
the other extremity of the connecting rod come into a right line as indicated by the
dotted lines in Fig. 6, which is timed to occur at the moment the blank holder reaches
the right point in relation to the blank and the die for holding it. Then the part of the
connecting rod swings with the crank i during the rest of the forward movement of
the rock-shaft and during its return to the said right line, as indicated by dotted
lines u in Fig. 6, during which time the blank holder rests and is positively and
unvaryingly held in position.
One of the parts of this connecting rod as k, is made extensible by the swivel
screw w, or other approved means to adjust the parts with exactness.
Two links m are employed in connecting the bell-crank and the blank holder at
opposite sides of the drawing punch, which works in the centre of said holder, and to
have better control for causing the blank holder to seat fairly on the blank, which is
important in view of the large area of the face of the blank holder which demands
great nicety of adjustment. The bed die which is to be of the cominon form and will
be located on the supporting bed plate as usual in such machines is not shown in the
drawings, as it forms no part of the invention claimed.
For large presses it is desirable to duplicate the blank holder actuating devices for
distributing the stresses, and for greater ease of operation, which may be carried out
in various arrangements one of which I have represented in Figs. 13 and 18. wherein
two rock-shafts and cranks i' are employed on opposite sides of the vertical plane
of the crank-shaft, with two connecting rods as j-k which may be connected at "
with the cross-head o' connected to the blank holder g 2 by any approved means as
links 2; the drawing punch n 4 is connected to the crank-shaft a, as in the other
arrangements.
The cranks e¹ of these rock-shafts are connected by links a¹ with a yoke ¹ coupled
by connecting rod c' with the crank d' of the main driving shaft. The connecting
rods, have like knuckle joints and the rock-shaft cranks have corresponding
channels p (dotted Fig. 13) admitting the extension pivots n' to the axis of
the rock-shafts for articulation of the joints while the blank holder is at rest.
j
In Figs. 14 and 19, I represent an arrangement whereby the same articulating
connecting rod and rock-shaft may be employed for operating a reciprocating device
as the slider k 5, which may be utilized as an intermittent feeder as for feeding blanks
to a press and the like where a long dwell of the feeder is required. In this case the
rock-shaft 2 is represented as geared by a toothed pinion y 2 with a reciprocating
toothed rack 2 connected by rod with the crank j2 of the main shaft a 2 suitably
for being rocked forward and backward and the jointed connecting rod j 3-k 3 is
connected with the crank of said rock-shaft, said crank having like channels p as in
Figs. 4 and 5 and the connecting rod having like pivot extensions n 2 for lodging in
the axis of the crank-shaft and interrupting the transmission of motion by the
connecting rod.
It will be seen that with this improved apparatus of my invention it is feasible to

page_text: cause the dwell of the blank holder during nearly
half revolution of the punch
driving shaft, and to vary it to any desired limit of less extent.
In Figs. 15, 16 and 17, I represent a simple and economical construction of presses
in which it is made feasible by my invention to utilize the rock-shaft for working
both the blank holder and the drawing punch. In this case the blank holder g¹ is
suspended directly from the rock-shaft/2 by a pair of knuckle jointed connecting
rods j 4, 4, or it may be by one only, and cranks and preferably so that it works
upwardly against a stationary bed die l whercon it comes to rest with the blank upon
its upper face when the cranks from which it is suspended pass the upper centre, and
the drawing punch n 3, is geared with an intermediate crank m 4 of the rock-shaft same
as in the other plans, said crank being set in suitable relation to the others for the
punch to take effect on the blank when the blank holder comes to rest or immediately
thereafter, and draw it downward in the bore of the blank holder which is in this
case the drawing die.
The rock-shaft may be worked by a hand lever as o 2 in the case of small presses, or
it may be geared by a crank and connecting rod with a rotary driving shaft as in
Fig. 1.
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 :-
1. The combination of the rock-shaft having a crank, a knuckle jointed rod
connected with the crank, and means to cause the pivot of the knuckle joint to lodge
and rest in the axis of the rock-shaft and maintain one portion of the rod at rest
during the further movement of the other portion with the crank substantially as
described.
2. The combination of the rock-shaft, the crank of said rock-shaft having the lateral
channel or channels into the axis of the rock-shaft, and the knuckle jointed connecting
rod having a pivot extension or extensions of the knuckle joint adapted to enter said
channel or channels and lodge in the axis of the shaft to permit one portion of the
rod to rest during further swing of the other portion of said rod with the crank
substantially as described.
3. The combination of the rock-shaft, the crank of said shaft having the lateral
channel or channels into the axis of the rock-shaft, and the knuckle-jointed connection
rod one part of which is of equal length with the crank, said joint having a pivot
extension or extensions adapted to enter said channel or channels and lodge in the
axis of the shaft to permit one portion of the rod to rest during the further movement
of the other portion of said rod with the crank substantially as described.
4. The combination of the rock-shaft having a crank, a knuckle-jointed rod
connected with the crank, means to cause the pivot of the knuckle joint to lodge and
rest in the axis of the rock shaft and maintain one portion of the rod at rest during
the further movement of the other portion with the crank, a blank holder coupled
with the resting part of the connecting rod, and a drawing punch coacting with the
blank holder substantially as described.
5. The combination with the blank holder, of a rock-shaft, the crank of said shaft
having a lateral channel or channels into the axis of the rock-shaft, and the knuckle-
jointed connecting rod coupled with said crank and blank holder, and having a pivot
extension or extensions of the knuckle joint adapted to enter said channel or channels
and lodge in the axis of the shaft to permit one portion of the rod to rest and
maintain the blank holder at rest while the other portion of said rod has further
movement with the crank substantially as described.
6. The combination with the blank holder, of a rock-shaft, the crank of said shaft
having a lateral channel or channels into the axis of the rock-shaft, the knuckle-
jointed connecting rod coupled with said crank, and the bell crank coupled with said
connecting rod and the blank holder, and having a pivot extension or extensions of
the knuckle-joint adapted to enter said channel or channels and lodge in the axis of
the shaft to permit one portion of the connecting rod to rest and maintain the blark

page_text: holder at rest while the other portion of said rod has further movement with the
crank substantially as described.
7. The combination of a rock-shaft having a crank, a blank holder, a knuckle-
jointed rod connecting said blank holder with the crank, means to cause the pivot of
the knuckle joint of said rod to lodge and rest in the axis of the crank-shaft, and
maintain the blank holder at rest during part of the movement of the crank, and a
drawing punch also connected to a crank of said rock-shaft and timed with relation
to the blank holder for taking effect on the blank while the blank holder is at rest
substantially as described.
8. The combination of the rock-shaft, a blank holder, one or more knuckle-jointed
connecting rods suspending the blank holder from one or more cranks of said rock
shaft, means to cause the pivot or pivots of said connecting rod or rods to lodge in
the axis of the crank-shaft and maintain the blank holder at rest during part of the
movement of the crank or cranks, a stationary die located over the blank holder, and
a drawing punch also connected to a crank of said shaft and timed with relation to
the blank holder for taking effect on the blank while the blank holder is at rest
substantially as described.
PHILIP M. JUSTICE,
Chartered Patent Agent, London,
For the Applicant.