Improvements in Safety Attachments for Stamping and like Presses.
Year: 1899

page_text: Date of Application, 11th Jan., 1899-Accepted, 22nd Apr., 1899
COMPLETE SPECIFICATION.
Improvements in Safety Attachments for Stamping and like Presses.
We, THOMAS ANDREW DICKS, of Buffalo, in the County of Eric; WILLIAM
ANDREW WARMAN, of Rochester, in the County of Monroe, both in the State of
New York, Machinists, MAXIMILIAN HENRY FISCHER, Advertising Agent, and IDA
HATTIE FISCHER, both of Gregory Avenue, West Orange, in the County of Essex,
State of New Jersey, all in the United States of America, 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:
This invention relates to a safety attachment for stamping and other like
presses whereby injury to the hands of the operator is prevented. This attach-
ment consists essentially of a guard or detector which moves in advance of the
punch and which, if it encounters the hand of the operator or some other obstrue-
tion, prevents the puuch from moving but which permits the latter to operate
if no obstruction is encountered.
This guard or detector can be operated in various ways. The accompanying
drawings consisting of three sheets show two different ways of operating the
same. In the preferred construction which is represented on Sheets 1 and 2 of
the drawings, Figures 1 to 9, the guard or detector is applied to a power press
and the power for moving the guard is derived from the driving mechanism
and the press can be run continuously when desired, thereby relieving the operator
and maintaining the full capacity of the press. In the construction represented
on Sheet 3, Figures 10 to 13, the guard or detector is applied to a hand press
and the work of moving the guard devolves on the operator and the latter is
required to depress the treadle which controls the guard every time the punch is
desired to descend.
Figure 1 is a front elevation of a power stamping press provided with our
improved safety attachment and showing the latter in its elevated and inoperative
position. Figure 2 is a similar view showing the driving clutch in section and
the safety attachment in its lower and operative position. Figure 3 is a frag-
mentary front elevation of the safety attachment, showing the position of the
parts when the guard or detector strikes an obstruction. Figure 4 is a frag-
mentary front elevation, showing a modified form of the guard or detector.
Figures 5, 6 and 7 are vertical sections in lines 55, 66 and 7-7, Figure 1,
respectively. Figure 8 is a fragmentary vertical section in line 8-8, Figure 2.
Figure 9 is a fragmentary end elevation of the driving shaft of the press and
connecting parts viewed from the side opposite to that shown in Figures 5 and 8.
Figure 10 is a side elevation of a foot-press provided with a modification of our
guard mechanism and showing the position of the parts when the punch is raised.
Figure 11 is a similar view showing the position of the parts when the guard in
its descent strikes an obstruction adjacent to the die. Figure 12 is a similar
view showing the position of the parts when the guard descends freely. Figure 13
is a fragmentary vertical cross section, on an enlarged scale, in line 1313,
Figure 10.

page_text: Like letters of reference refer to like parts in the several figures.
The power stamping press for working on sheet metal or other material shown
in Figures 1-9 of the drawings consists essentially of a base A, two stan-
dards BB', a die & mounted on the base, a punch co-operating with the die
and mounted on a vertically movable cross head D which is guided on the stan-
dards, a horizontal driving shaft E journalled in bearings at the upper end of
the standards and having an eccentric or crank e connected with the cross head
by a rod e¹, and a continuously rotating driving wheel or pulley F which is
mounted on one end of the shaft and is coupled therewith or uncoupled therefrom
by a clutch, all of which parts may be of any usual or suitable construction. The
clutch shown in the drawings is of well known construction and consists of a
coupling barg journalled lengthwise in the shaft and adapted to engage with
one of a number of notches g¹ in the bore of the driving wheel Figures 2 and 6,
a depending rock arm g arranged on the inner end of the coupling bar, and a
spring connecting the rock arm with a collar on the shaft, Figure 5. Upon
turning the coupling bar so that it does not engage with a notch in the driving
wheel the spring is strained and the driving wheel rotates without turning the
shaft. Upou releasing the rock arm the latter is turned by the spring together
with the coupling bar so that the latter engages in one of the notches in the
driving wheel, whereby the wheel and shaft are coupled together and the shaft
is turned.
H represents a vertically movable stop arm with which the clutch rock arm g
is adapted to engage and whereby the latter is moved for uncoupling the clutch.
The stop arm H is pivoted at its rear end to the standard B and when free it
is drawn downwardly by a spring à so that its front end clears the clutch rock
arm, Figure 8. His a lifting lever whereby the stop arm is raised so that its
front end stands in the path of the clutch arm and uncouples the clutch, Figure 5.
The lifting lever is pivoted on the standard B and engages with its short lower
arm against a depending lug h of the stop arm. The upper arm h³ of the
lifting lever is provided with a laterally projecting roller or lug ht.
I represents a vertically movable slide which is guided in a way i on the
standard B and which is provided at its upper end with an inclined face and
below the same with a vertical front face, Figure 7, said faces being arranged
to engage alternately with the roller h of the lifting lever. Upon raising the
slide the incline engages with the roller and guides the same upon the vertical
face of the slide, whereby the lifting lever is turned for raising the stop arm into
its operative position. Upon lowering the slide until its vertical face has cleared
the roller of the lifting lever the stop arm is turned downward by the spring h
and the lifting lever is thereby swung with its upper arm backward. Thia
releases the clutch arm and causes the shaft and driving wheel to be coupled.
The downward movement of the slide is effected by gravity, aided, if necessary,
by a spring which connects the slide with the standard B, as shown in Figure 7.
The upward movement of the slide is effected by the driving mechanism which
operates the punch. The means for that purpose shown in the drawings consists
of a rock lever K which is arranged across the front of the press below the
driving shaft and which is connected with the slide by a slot which receives
apin on the slide, and which is actuated by a cam secured to the shaft on
the opposite side of the press, Figures 1, 2 and 3, the adjacent arm of the rock
lever being preferably provided with roller . The slide is held in its elevated
position by a catch L, pivoted on the standard B and adapted to engage under a
pin or shoulder on the slide when the latter is in its elevated position. As
shown in Figures 5 and 8, this pin projects laterally through a vertical slot
in the guide way. The catch is furned and yieldingly held in engagement with
the pin or shoulder of the slide by a spring 12.
=
M represents a releasing lever which is connected by a rod m with a rear-
wardly projecting arm on the catch. Upon depressing this lever the notch is

page_text: and the slide is free to descend. This releasing lever is shown in the drawings
for convenience as being arranged on the side of the base of the press, in which
location it will have to be depressed by the hand of the operator, but most gener-
ally it will be arranged on the floor as a treadle, so that the operator can depress
it by the foot and have both hands free for manipulating the material operated
upon.
N represents the guard or detector which descends in advance of the punch
and controls the operation of the clutch which couples the driving wheel to the
shaft. Thus guard or detector extends across the front side of the punch and is
secured to the lower horizontal arm o of an elbow lever o. The latter is pivoted
to the lower end of the slide and its upper vertical arm extends upwardly
between the gibs out of the guide way in which the slide moves.
The upper
end of the vertical arm of this elbow fever is provided on its outer side with
teeth P which face a vertical row of similar teeth on the outer gib ot. The
lever is yieldingly held against the inner gib o, with its teeth out of engage-
ment with the teeth of the outer gib, by a spring 9 secured to the upper arm
of the lever and bearing against the lower smooth portion of the outer gib.
When the machine is at rest the punch stands in its elevated position and the
detector and connecting parts are also in their elevated position and held in this
position by the catch L, as shown in Figures 1 and 5. In this position of the
parts the driving wheel is uncoupled from the shaft and the punch cannot be
operated. In order to start the press it is necessary to release the catch and
drop the detector. This is done by depressing the releasing lever M, as described.
If the space below the detector is obstructed by nothing except the sheet of
material or blank to be operated upon, the detector and the slide connected there-
with descend to their lowest position, in which position the incline at the upper
end of the slide permits the lifting lever H, to turn with its lower arm down-
wardly and release the stop arm H from the clutch arm g, thereby coupling
the driving wheel with the shaft and causing the punch to move toward the die
and perforate the material. During the upward movement of the punch the
detector and slide are also raised by the cam acting upon the rock lever K.
As the slide approaches the limit of its upward movement the incline at its
upper end swings the upper arm of the lifting lever H forwardly and the lower
arm of this lever upwardly, whereby the stop arm H is swung upwardly into
the path of the clutch arm, so that when the latter during its rotation in the
direction of the arrow in Figure 8 strikes the stop arm, it is arrested, thereby
turning the coupling bar in the proper direction for uncoupling the shaft from
the driving wheel. When the operator desires to stop the operation of the press
after each effective movement of the punch he releases the catch L by the
releasing lever for starting the press and then lets go of the releasing lever, so
that the catch locks the slide in its elevated position at the end of the next upward
movement of the slide. When the slide is so locked it holds the stop H in the
path of the clutch arm and this causes the uncoupling of the clutch and the
stoppage of the punch. When the operator desires the press to work continuously
he holds the catch out of engagement with the slide by keeping the releasing
lever depressed. In this position of the catch the slide is not locked in its elevated
position but drops as soon as its actuating cam releases the rock lever K,
which takes place as soon as the slide has finished its upward stroke. If the
detector encounters no obstruction during its downward movement the stop arm
is dropped out of the path of the clutch arm before the latter has been held long
enough to uncouple the clutch and the rotation of the shaft and the operation
of the punch continues. The punch and the detector move up together but the
detector always moves down before the punch begins its next downward move-
ment and the punch is only allowed to perform its next downward movement if
the detector has encountered no obstruction in its downward movement. If the
detector has encountered an obstruction it causes the uncoupling of the shaft before
the next downward movement of the punch takes place and so stops the same.

page_text: When the detector strikes an obstruction in moving toward the die, the elbow
lever by which it is connected with the slide is turned so that the teeth in its
upper arm engage with the teeth on the guide way, as shown in Figure 3. The
detector is thus interlocked by this elbow lever with the frame of the machine
and the weight of the detector elbow or locking lever and slide is transferred to
the frame instead of resting on the hand of the operator or other obstruction.
This is desirable in large presses in which the weight of these parts may be
considerable.
In small presses the detector may be rigidly secured to the slide, as shown in
Figure 4, in which case the weight of the detector and slide rests upon the
obstruction which it encounters. The detector is preferably so. timed that when
it is in its lowest position it encloses the front side of the die and punch until
the punch has effected its downward movement and that the detector moves
upwardly with the punch, whereby the operator is prevented from obstructing
the die after the detector has shifted the parts for operating the punch.
In this construction of safety attachment the attendant releases the detector
slide and the latter operates the clutch and the attendant is prevented from
operating the clutch directly. By this means the coupling of the driving wheel
and shaft is controlled entirely by the position of the detector slides, the latter
when dropped to its full extent operating to couple the driving wheel and shaft
while if the slide does not drop to its full extent it prevents these parts from
being coupled.
As the detector and its slide are raised by the actuating mechanism of the
punch and lowered by gravity, aided, if necessary, by spring power, the atten-
dant is relieved from the exertion of moving the detector, the only movement
which the attendant is required to perform being to release the catch which
bolds the detector slide.
A modified form of the guard mechanism designed for foot prosses is shown
in Figures 10-13 and is constructed as follows:-
R represents the actuating rock lever which is pivoted on the standard A¹ and
which is connected at its front end with the punch carrier or slide s for moving
the latter in its guide and the punch C toward and from the die ỗ on the
base A B is the treadle connected with its rear arm to the rear arm of
the rock lever by a connecting rod. The punch is normally held in an elevated
position by a weight mounted on the rear arm of the lever R in the usual manner.
T represents a stop or catch pivoted with its lower end on the upper end of the
standard and provided at its upper end with a shoulder t which is adapted to
engage with a rearwardly projecting lug on the upper end of the slide. The
upper end of the catch is yieldingly moved forward into the path of the slide
lug by a spring 2 connecting the lower end of the catch with the standard, this
forward movement of the catch being limited by a stop on the standard. The
catch is provided on its side adjacent to the pivot with an inclined trip face or
shoulder.
uu8 represent a pair of rock levers pivoted one above the other on the side
of the standards and pivotally connected at their outer ends by a vertical con-
necting bar with the guard or detector G. The rock levers and the detector
are normally held in an elevated position by a spring u³ connecting the rear end
of the upper rock lever with the standard. The upper rock lever is arranged
with its front arm in the path of the shoulder on the catch and is adapted to
engage therewith in the normal operation of the mechanism for removing the
catch from underneath the lug of the slide and permitting the latter to descend
with the punch. V represents a cam which is pivoted on the side of the standard
and which is adapted to engage with a pin on the lower rock lever for depressing
the same and the detector in advance of the downward movement of the punch.
This cam is yieldingly held in its retracted position by a spring and is turned
in the direction of the arrow for lowering the detector by a chain in which is
fastened with its ends to the cam, and to a spring w³ on the rear arm of the slide
---

page_text: operating lever and passes with its intermediate portion around rollers mounted
on the table or bed of the foot press. In the normal or retracted position of the
parts as shown in Figure 10 the lug of the slide is arranged a short distance
above the catch and the latter is arranged with its shoulder underneath the slide
lug with its inclined trip face fat an angle to the upper lever u which sup-
ports the guard. Upon depressing the treadle when no obstruction is on 'or
adjacent to the die, the first portion of the downward movement of the front arm
of the treadle causes the cam V to be turned by the slide lever R and chain w,
thereby lowering the guard or detector in advance of the downward movement
of the punch. As the guard descends the upper rock lever supporting the same
bears against the trip face of the catch and turns the same in the direction
of the arrow, Figure 10, until the upper rock lever bears flatly against the
entire trip face of the catch whereby the upper end of the latter is moved rear-
wardly from underneath the slide lug and the slide is permitted to move down-
ward its full extent with the punch, as represented in Figure 12. If an obstruc-
tion prevents the guard from moving downward its full extent the upper rock
lever will not shift the catch T rearwardly so as to clear the slide lug which
causes the latter during the initial portion of its downward movement to strike
the catch, as shown in Figure 11, whereby it is arrested against further downward
movement. The spring forms a yielding connection between the slide lever
and the guard operating mechanism so as to prevent the guard from injuring
the hand of the operator in bearing upon the same,
"
"
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. The combination with the punch or plunger of a detector which is inde-
pendent of said punch or plunger and which is caused to move toward the die
before the punchi or plunger begins its effective movement, and a stop device
which is controlled by said detector and which prevents the effective movement
of the punch or plunger when the normal movement of the detector does not take
place.
2. The combination with the punch or plunger and the mechanism which
actuates the same, of a detector which controls said actuating mechanism and
which moves toward the die of the press before the punch or plunger begins its
effective movement, and mechanism by which the detector is moved away from
the die and which is actuated by the punch actuating mechanism and which
releases the detector and allows the latter to move toward the die before the
punch or plunger makes its effective stroke.
3. The combination with the die, the punch, the mechanism, which actuates
the punch, and the driving clutch, of a detector which controls said driving
clutch and which moves toward the die before the punch makes its effective
stroke, and mechanism by which the detector is moved away from the die and
which is actuated by the punch actuating mechanism.
4. The combination with the die, the punch, and the mechanism which actuates
the punch, of a detector, which controls said mechanism and which moves toward
the die before the punch makes its effective stroke, a catch whereby the detector
is releasably held in its retracted position, and mechanism by which the detector
is moved away from the die and which is actuated by the punch, actuating
mechanism.
5. The combination with the die, the punch and the mechanism which actuates
the punch, of a detector which controls said mechanism and which moves toward
the die before the punch makes its effective stroke, mechanism by which the
detector is moved away from the die and which is actuated by the punch actuating
mechanism and release the detector before the punch makes its effective stroke,
and a catch which prevents the detector, when so released, from moving toward
the die until the catch is released by the operator.

page_text: 6. The combination with the die, the punch, and the mechanism which actuates
the punch, of a detector which controls said mechanism and which moves toward
the die before the punch makes its effective stroke, and a catch which controls
the movement of the detector toward the die and prevents such movement unless
released by the operator.
7. The combination with the die, the punch, and the mechanism which
actuates the punch, of a slide which controls said mechanism and which is pro-
vided with a detector, a catch whereby the slide and the detector are releasably
held in a retracted position, and mechanism by which the slide and detector are
moved away from the die and which is actuated by the punch actuating
mechanism.
8. The combination with the die, the punch, the mechanism which actuates
the punch, and the driving clutch, of a slide provided with a detector which
moves toward the die in advance of the punch, a movable stop arm adapted to
uncouple said clutch, and a lever which moves the stop arm into its operative
position and which is shifted by said slide.
9. The combination with the die, the punch, the mechanism which actuates
the punch, and the driving clutch, of a slide controlling said clutch and pro-
vided with a detector which moves toward the die in advance of the punch, a
rock lever connected with said slide, and a cam connected with the actuating
mechanism of the punch and engaging with said rock lever.
10. The combination with the frame, the die, the punch, the mechanism. by
which the punch is actuated, and the driving clutch, of a slide controlling said
clutch, and provided with a detector, and a locking device connected with the
detector and interlocking the slide and the detector with the frame when the
detector strikes an obstruction.
11. The combination with the die, the punch, the mechanism which actuates
the punch, and the driving clutch, of a slide which controls said clutch and
which is provided with a detector and with a pin or shoulder, mechanism whereby
said alide is moved away from the die, a catch whereby the slide and detector
are locked in an elevated position, and a releasing lever connected with said
catch.
12. The combination with the die, the punch, the mechanism which actuates
the punch, and the driving clutch of a slide which controls said clutch and
which is provided at its lower end with a detector and at its upper end with an
inclined face, lifting lever which is operated by said inclined face, and a stop
arm which is moved by said lifting lever to uncouple the clutch.
Dated this 11th day of Jansions 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.