US3213729A

US3213729A - Punch press

Info

Publication number: US3213729A
Application number: US275269A
Authority: US
Inventors: Richard C Koch
Original assignee: ROCHEZ BROS Inc
Current assignee: ROCHEZ BROS Inc
Priority date: 1963-04-24
Filing date: 1963-04-24
Publication date: 1965-10-26
Anticipated expiration: 1982-10-26

Description

Oct. 26, 1965 R. c. KOCH 3,213,729

PUNCH PRESS Filed April 24, 196s s sheets-sheet 1 INVENTOR.

` RICHARD CKOCH ATTORNEYS R. C. KOCH PUNCH PRESS Oct. 26, 1965 3 Sheets-Sheet 2 Filed April 24, 1965 om my ws mw United States Patent 3,213,729 PUNCH PRESS Richard C. Koch, St. Clair Shores, Mich., assigner to Rochez Bros. Inc., East Pittsburgh, Pa., a corporation of Pennsylvania Filed Apr. 24, 1963, Ser. No. 275,269 2 Claims. (Cl. 83-124) This invention relates generally to punch presses and refers more particularly to a punch press adapted to form annular stampings.

One object of the invention is to provide a punch press which is extremely versatile and, with minor changes, capable of producing stampings of many different shapes and sizes.

Another object is to provide la punch press designed so that the various parts determining the size and shape of the stamping can be readily changed.

Another object of the invention is to provide a punch press having readily interchangeable dies and punches.

Another object of the invention is to provide a punch press having a tubular compound blank, punch and pierce die mounted on a stationary portion of the press, a second die mounted on a movable carrier and operable to blank a stamping in cooperation with the outer margin of the compound die, a punch on the carrier cooperable with the inner margin of the compound die to punch and pierce the blank, a knockout on the carrier for stripping the annular stamping from the punch and die on the carrier, and a stripper for stripping the remaining stock from the compound die, the dies, punch and stripper being so mounted as to be readily removable for replacement by other similar parts having different dimensions Another object is to provide a punch press as defined in the preceding paragraph in which the die, punch and stripper are mounted in open recesses permitting the same to be installed and removed very readily.

Another object is to provide a member for operating the knockout, which members is mounted on the carrier and operated by a iixed stop upon rearward movement of the carrier.

Another object is to provide knockout pins on the carrier to facilitate the removal of the die and punch mounted thereon, which pins normally clear the stop upon retraction of the carrier but which are engageable with the stop when the stop is adjusted to a different position so as to effect removal of the die and punch.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a top plan View of a punch press embodying my invention.

FIGURE 2 is a sectional view taken on the line 2-2 of FIGURE 1.

FIGURE 3 is an enlarged fragmentary sectional view of portions of FIGURE 2, showing the piston forward and i-n the process of blanking and punching an annular stamping from a length of stock.

FIGURE 4 is an enlarged fragmentary view, with parts in section, of the structure of FIGURE 1, showing the piston in an intermediate position.

FIGURE 5 is a sectional view taken on the line 5-5 of FIGURE 3.

Referring now more particularly to the drawings, the punch press comprises a fixed frame which includes a base 11 and an upright stationary rear support 12 which mounts the compound die 14 and stripper assembly 16. A cylinder 18 is secured on the base and slidably supports a carrier or piston 20 for forward and rearward movement. The piston 20 mounts the button die 22, the

Pce

punch 24 and the knockout 26. A member 23 engages a longitudinal groove 25 in the piston to prevent rotation of the piston. The piston and various members mounted thereon make up the movable assembly of the punch press.

The piston 20 is operated by a shaft 28 from a source of power not shown. The shaft 28 is journalled for rotation in the ears 30 of the block 32 and has an eccentric portion 34 between the ears on which is sleeved one end of the crank 36. The other end of the crank is pivoted to a bracket 38 on the rear end 4of piston 20 by a pin 40. It will be apparent that rotation of shaft 28 will result in forward and rearward axial reciprocation of piston 20. The block 32 is slidable in a recessed guide 42 of the base 10 and is engaged by a screw 44 rotatably mounted on the rear end of the frame by a mounting 46 which prevents axial movement of the screw. The rotation of the screw by handwheel 48 will effect an initial setting of the block 32 in the desired position of longitudinal adjustment.

The compound blank, punch and pierce die 14 is a tubular member having a cylindrical inner surface 50 which is reduced in diameter at its rear end as indicated at 52. The outer surface 54 of the rear, projecting portion of the compound die is cylindrical and concentric with the inner surface 52, and a rear radial face 55 connects in a sharp right angle cutting edge with each of the

cylindrical surfaces

52 and 54. As shown, screws 56 which thread into the rear surface of the fixed support 12 have locking heads 58 which t into notches 60 of the compound die to lock it in position. The periphery of the locking head 58 of each screw may be relieved on one side so that by a mere twist of the screw the locking periphery -of the head will withdraw from the notch to release the compound die and permit it to be Withdrawn from the recess 62 in the rear face of the support. Since the recess 62 is open at the rear and extends in a front to rear direction, the compound die may be removed when released by screws 56, by a direct rearward pull, and may be easily installed in the same manner by a reverse movement.

The rear projecting portion of the compound die is surrounded by the stripper assembly 16. The stripper assembly is mounted on the ixed support 12 for movement axially of the compound die, that is in forward and rearward directions, by the bolts 64. Bolts 64 parallel to the compound die, are threaded in the fixed support 12 and are slidably received in the passages 66 in the retainer 68 of the stripper assembly. The passages 66 have enlarged rear portions 70 receiving the heads 72 of the bolts, and the shoulders 74 provided by the enlarged passage portions are engageable with the ends of the bolts to limit the rearward movement of the stripper assembly to the position shown in FIGURE 4. Coil springs 76 carried by the iixed support 12 press against the stripper assembly to urge it in a rearward direction.

The retainer 68 is an annular member which is coaxial with and surrounds the compound die. The retainer is formed with a recess 80 in its rear face which opens into the inner surface of the retainer and provides a seat for the annular stripper or stripper insert 82. The stripper insert is a cylindrical ring, and the cylindrical inner surface 84 thereof is concentric with and closely surrounds the compound die. The sharp rear edge of `the inner surface 84 connects with a radial rear surface 86. At the rearward limit of stripper travel, shown in FIGURE 4, the rear surface 86 projects rearwardly of the radial rear face 55 of the compound die. The stripper assembly can be moved forwardly, as shown in FIGURE 3, in which case the face 86 is in front of the projecting rear end of the compound die. The stripper insert 82 has notches 90 engaged by the 3 heads 92 of the screws 94 threaded into the retainer 68. The locking heads 92 of the screws are relieved so that a partial turn will withdraw the head from the notch and permit the insert to be removed. The removal and installation of the stripper insert is easily accomplished by a direct axial movement.

The piston 20 has an open axially extending recess 96 in its front end which is coaxial with the compound die 14. The

liners

98 and 100 are xed within the recess. The button die 22 is removably locked in the front end of the recess by the screws 102 which screws have locking heads 104 engaging in notches 106 of the button die. Here again, the ends are non-circular or relieved so that by a partial turn of the screws the heads withdraw from the notches to release the button die and permit it to be removed. The button die is an annular member and its inner surface 108 is cylindrical, concentric with the cornpound die and of a slightly larger diameter so that the end of the compound die can be received within the button die during a blanking operation, as shown in FIGURE 3. The front radial face 109 of the button die connects with cylindrical surface 108 in a sharp edge.

The punch 24 has a base portion which is locked in a longitudinal opening in the liner 100 by screws 110 which have locking heads 112 engaging in notches 114. The locking heads 112 are relieved along one side so that by turning the screws a partial turn the locking heads withdraw and release the punch for removal. The front end portion 116 of the punch is cylindrical and axially aligned with the compound die and of a slightly smaller diameter than the reduced rear end portion 52 of the inner surface of the compound die, so that the punch can enter the compound die in a punching and piercing operation, as shown in FIGURE 3. 'I'he front end of cylindrical portion 116 of the punch is in the plane of the front radial face 109 of the button die, and is joined to its own outer cylindrical surface in a sharp edge.

The knockout 26 is an annular member which surrounds the front portion 116 of the punch within the space between the punch and the button die. The knockout is movable axially between positions in which its radial front end 119 is rearward of the aligned rear ends of the button die and punch (FIGURE 3), or forwardly thereof. The knockout has an annular rear end flange 120 of enlarged diameter, and a resilient ring 122 may be provided if desired between the flange and the shoulder 124 on the button die to make sure that the front end of the knockout will normally be located to the rear of the front faces of the punch and button die.

The knockout 26 is moved forwardly to strip an annular stamping from the punch and button die following a blanking and punching operation by an axially movable member 130 slidably mounted in an axial passage 132` of the piston 20. The member 130 has a flange 134 on the front end provided with axially extending pins 136 which slide freely in passages formed in

liners

98 and 100 and have their front ends engageable with the ange 120 of the knockout. When the piston is withdrawn in a rearward direction, the rear end of the member 130 will engage a stop bar 140 to move the member 130 in a forward direction relative to the piston, causing pins 136 to engage and project the #knockout to a position in which its front end projects beyond the button die and punch to strip the stamping.

The stop bar 140 is an elongated member carried by the cylinder 18 in axially adjusted position. The stop bar extends across the cylinder, and axially elongated slots 142 in either side of the cylinder wall clear the projecting ends of the bar and enable the bar to be shifted and secured in various positions of axial adjustment. The rear end portion is slotted across its full width, as shown at 141, in the plane of passage 132, to clear the stop bar 140. Clamping plates 144 on either side of the cylinder are slotted to slidably receive the stop bar and have the axially elongated slots 146 receiving the fasteners 148 carried by and projecting from the cylinder. The elongated character of the slots 146 enables the clamping plates and hence the stop bars to be clamped by the fasteners 148 in axially adjusted position. The fasteners 148 may be shifted rearwardly to the threaded holes 150 in the cylinder to clamp the stop bar 140 in a position considerably to the rear of the position shown in FIGURE 2. (See the dotted line position of the stop bar 140 in FIGURE l.)

Axially extending knockout pins 152 and 154 are provided. The pins 152 are slidable in passages formed in the piston and in the

liners

98 and 100, and their front ends are engageable with the button die 22. Their rear end portions are shown in FIGURE 4 as extending through passages 156 in the stop bar. The knockout pin 154 slidably extends through the axially movable member 130 and its front end is adapted to engage the punch 24. Its rear end slides through the passage 158 in the stop bar, as shown in FIGURE 4.

The punch press is designed to form annular stampings from a strip of stock S which passes between the cornpound die and the front end of the piston. The piston has its axis aligned with the compound die and is axially reciprocable by the power driven eccentric shaft 28 between an advanced or forward position shown in FIG- URE 3 and a retracted position rearward of the intermediate position shown in FIGURE 4. During the advance of the piston, the knockout 26 is preferably located with its front end somewhat to the rear of the aligned front ends of the button die and punch, as shown in FIG- URE 4. The annular resilient ring 122 of rubber or the like accomplishes this purpose. The springs 76 hold the stripper assembly at its rear limit in which the .rear face 86 of the stripper insert is substantially flush with the rear face 55 of the compound die. The continued advance of the piston causes the punch 24 to enter compound die 14, piercing and punching the stock as shown in FIGURE 3. At the same time the compound die 14 enters the button die 22 to blank the stamping from the stock. The button die 22 pushes the stripper assembly 16 forward with it, as shown in FIGURE 3.

On initial retraction or rearward movement of the piston the stripper assembly springs rearward to strip the stock from the compound die. The slug of metal may be cleared from the inside of the compound die through the outlet passage 170. There may be some pile-up of slugs in the compound die, but this will not interfere with the operation.

As the piston nears the end of its rearward movement, the axially :slidable member 130 engages the stop bar 140 to advance the member 130 with respect to the piston far enough to push the knockout 26 so that its front end projects beyond the aligned front ends of the button die 22 and punch 24. The annular stamping is thereby stripped away and falls through the discharge opening 172. The position of the stop bar is axially located so that it will engage the member 130 prior to the end of rearward movement of the piston and achieve the desired relative forward movement of the knockout. On the next forward stroke of the piston, the knockout will of course be pushed back by the action of the compound die 14 or, if a resilient ring 122 is provided, the ring will push back the knockout.

The compound die 14 and stripper insert 82 are easily removed by merely turning the

screws

56 and 94 to unlock them. When unlocked or released, the compound die and stripper insert can be removed by a straight rearward movement, since the recesses 62 and 80 in which they seat extend axially and open in a rearward direction. Assembly is just as easy by a reverse movement.

The button die 22 and punch 24 can be readily removed by movement in a forward direction since they are disposed in an axially extending forwardly opening recess 96. Initially, of course, the screws retaining them ywill have to be turned. Installation is easily accomplished by a reverse movement.

salame The knockout pins 152 and 154 are provided to push or poke the punch 24 and button die 22 out of their recesses. Thi-s can be doen with little effort. First of all, the stop bar will be moved to the dotted line position in FIGURE 1 and clamped in position by plates 144 which are held by fasteners 148 threaded in holes 150 in the cylinder 18. The bar can slide longitudinally in the slots in the plates 144, and therefore the stop bar will be shifted transversely so that the

passages

156 and 158 therein are out of alignment with the pins. Then the screw 44 is operated to withdraw the piston beyond its usual rearward limit until the pins engage the stop bar. Continued rearward movement of the piston will cause the pins to push the button die and the punch out of the recesses in thefront end of the piston.

It will be seen that the punch press is so constructed that the stripper insert, compound die, button die and punch can be very easily removed and replaced by other parts of different configurations. The knockout 26 is of course very easily removed as soon as the button die is removed. The various screws for releasably retaining the stripper insert, compound die, button die and punch are quick acting to enable fast assembly or disassembly. If desired, the entire stripper assembly 16 can be removed by taking out the bolts 64.

What I claim as my invention is:

1. A punch press for making annular stampings comprising a frame having a fixed upright die support, said support having a rearwardly facing surface provided with a recess, a compound blank, punch and pierce die removably mounted in said recess and having a rear face projecting rearwardly from said recess defined by an outer annular blanking edge and an inner annular piercing and punching edge, an annular stripping assembly encircling said compound die for stripping stock therefrom, said stripper assembly comprising an annular stripper generally coaxial with said compound die and having an inner margin closely surrounding said compound die and a rear face extending radially outward from said margin, an annular retainer for said stripper having an open recess in its rear surface in which said stripper is removably mounted, guides supporting said stripper assembly on said fixed support for forward and rearward movement, means urging said stripper assembly rearwardly, means limiting the rearward movement of said stripper assembly to a position such that the rear face of said stripper projects slightly rearwardly beyond the plane of the rear face of said compound die, and an assembly movable axially relative to said compound die in forward and rearward directions to blank and punch a piece of stock to form an annular stamping, said movable assembly comprising a carrier, a recess in the front end of said carrie-r, a second annular die removably mounted in the recess in said carrier and having an inner annular edge coaxial with and complementing in contour the outer annular edge of said compound die, said second die engaging said stripper assembly upon forward movement of said carrier to move said stripper assembly forwardly as a unit therewith, a punch removably mounted in said recess within said second die in axial alignment with said compound die and having at its front end a contour complementing that of the inner edge of said compound die, whereby upon forward movement of said carrier said punch enters said compound die and said compound die enters said second die to blank and punch an annular stamping from a piece of stock along the inner and outer edges of said compound die, an annular stamping knockout surrounding said punch in the space between said punch and second die, said knockout being axially slidable relative to said punch and second die between a forward position in which its front end projects forwardly beyond the front ends of said punch and second die and a rearward position in which its forward end is withdrawn rearwardly of said front ends, means for moving said knockout to its forward position in response to rearward movement of said carrier, said recesses in said xed support and in said retainer opening forwardly so that said compound die and stripper can be installed and removed by a straight forward or rearward movement, the recess in said carrier opening rearwardly so that said second die and punch can be installed and removed by a straight forward or rearward movement, quick-release locking members for releasably locking said compound die, stripper, second die and punch in their recesses, said means for moving said knockout to its forward position including an axially slidable member on said carrier having means at the front end engageable with said knockout upon forward movement there-of relative to said carrier to advance said knockout to its forward limit, an adjustable stop fixed on said frame and engageable with said member upon rearward movement of said carrier to move said member forwardly relative to said carrier, said carrier having passages therein extending from the rear end thereof forwardly to the carrier recess and respectively aligned with said second die and said punch, knockout pins slidable in said passages, said adjustable stop being formed to clear said pins in one position of adjustment during rearward movement of said carrier and to engage said pins upon rearward movement of said carrier in another position of adjustment to remove the second die and punch by the action of said pins, and means for locking said stop in adjusted positions.

2. A punch press for making annular stampings comprising a frame having a fixed upright die support, said support having a rearwardly facing surface provided with a recess, a compound blank, punch and pierce die removably mounted in said recess and having a rear face projecting rearwardly from said Irecess defined by an outer annular blanking edge and an inner annular piercing and punching edge, an annular stripping assembly encircling said compound die for stripping stock therefrom, said stripper assembly comprising an annular stripper generally coaxial with said compound die and having an inner margin closely surrounding said compound die and a rear face extending radially outward from said margin, an annular retainer for said stripper having an open recess in its rear surface in which said stripper is removably mounted, guides supporting said stripper assembly on said fixed support for forward and rearward movement, means urging said stripper assembly rearwardly, means limiting the rearward movement of said stripper assembly to a position Isuch that the rear face of said stripper projects slightly rearwardly beyond the plane of the rear face of said compound die, and an assembly movable axially relative to said compound die in forward and rearward directions to blank and punch a piece ofstock to form an annular stamping, said movable assembly comprising a carrier, a recess in the front end of said carrier, a second annular die removably mounted in the recess in said carrier and having an inner annular edge coaxial with and complementing in contour the outer annular edge of said compound die, said second die engaging said stripper assembly upon forward movement of said carrier to move said stripper assembly forwardly as a unit therewith, a punch removably mounted in said recess within said second die in axial alignment with said compound die and having at its front end a contour complementing that of the inner edge of said compound die, whereby upon forward movement of said carrier said punch enters said compound die and said compound die enters said `second die to blank and punch an annular stamping from a piece of stock along the inner and outer edges of said compound die, an annular stamping knockout surrounding said punch in the space between said punch and second die, said knockout being axially slidable relative to said punch and second die between a forward position in which its front end projects forwardly beyond the front ends of said punch and second die and a rearward position in which its forwa-rd end is withdrawn rearwardly of said front ends, means for moving said knockout to its forward position in response to rearward movement of said carrier, the recess in said carrier opening rearwardly so that said second die and punch can be installed and removed by a straight forward or rearward movement, quick-release locking members for releasably locking said second die and punch in their recess, said carrier having passages therein extending from the rear end thereof forwardly to the carrier recess and respectively aligned with said second die and said punch, knockout pins slidable in said passages, and an adjustable stop fixed on said frame and formed to clear said pins in one position of adjustment during rearward movement of said carrier and to engage said pins upon rear- Ward movement yof said carrier in another position of adjustment to remove the second die and punch by the action of said pins, and means for locking said stop in adjusted positions.

References Cited by the Examiner UNITED STATES PATENTS ANDREW R. JUHASZ, Primary Examiner.

LEON PEAR, Examiner.

Claims

1. A PUNCH PRESS FOR MAKING ANNULAR STAMPINGS COMPRISING A FRAME HAVING A FIXED UPRIGHT DIE SUPPORT, SAID SUPPORT HAVING A REARWARDLY FACING SURFAC PROVIDED WITH A RECESS, A COMPOUND BLANK, PUNCH AND PIERCE DIE REMOVABLY MOUNTED IN SAID RECESS AND HAVING A REAR FACE PROJECTING REARWARDLY FROM SAID RECESS DEFINED BY AN OUTER ANNULAR BLANKING EDGE AND AN INNER ANNULAR PIERCING AND PUNCHING EDGE, AN ANNULAR STRIPPING ASSEMBLY ENCIRCLING SAID COMPOUND DIE FOR STRIPPING STOCK THEREFROM, SAID STRIPPER ASSEMBLY COMPRISING AN ANNULAR STRIPPER GENERALLY COAXIAL WITH SAID COMPOUND DIE AND HAVING AN INNER MARGIN CLOSELY SURROUNDING SAID COMPOUND DIE AND A REAR FACE EXTENDING RADAILLY OUTEARD FROM SAID MARGIN, AN ANNULAR RETAINER FOR SAID STRIPPER HAVING AN OPEN RECESS IN ITS REAR SURFACE IN WHICH SAID STRIPPER IS REMOVABLY MOUNTED, GUIDES SUPPORTING SAID STRIPPER ASSEMBLY ON SAID FIXED SUPPORT FOR FORWARD AND REARWARD MOVEMENT, MEANS URGING SAID STRIPPER ASSEMBLY REARWARDLY, MEANS LIMITING THE REARWARD MOVEMENT OF SAID STRIPPER ASSEMBLY TO A POSITION SUCH THAT THE REAR FACE OF SAID STRIPPER PROJECTS SLIGHTLY REARWARDLY BEYOND THE PLANE OF THE REAR FACE OF SAID COMPOUND DIE, AND AN ASSEMBLY MOVABLE AXIALLY RELATIVE TO SAID COMPOUND DIE IN FORWARD AND REARWARD DIRECTIONS TO BLANK AND PUNCH A PIECE OF STOCK TO FORM AN ANNULAR STAMPING, SAID MOVABLE ASSEMBLY COMPRISING A CARRIER, A RECESS IN THE FRONT END OF SAID CARRIER, A SECOND ANNULAR DIE REMOVABLY MOUNTED IN THE RECESS IN SAID CARRIER AND HAVING AN INNER ANNULAR EDGE COAXIAL WITH AND COMPLEMENTING IN CONTOUR THE OUTER ANNULAR EDGE OF SAID COMPOUND DIE, SAID SECOND DIE ENGAGING SAID STRIPPER ASSEMBLY UPON FORWARD MOVEMENT OF SAID CARRIER TO MOVE SAID STRIPPER ASSEMBLY FORWARDLY AS A UNIT THEREWITH, A PUNCH TEMOVABLY MOUNTED IN SAID RECESS WITHIN SAID SECOND DIE IN AXIAL ALIGNMENT WITH SAID COMPOUND DIE AND HAVING AT ITS FRONT END A CONTOUR COMPLEMENTING THAT OF THE INNER EDGE OF SAID COMPOUND DIE, WHEREBY UPON FORWARD MOVEMENT OF SAID CARRIER SAID PUNCH ENTERS SAID COMPOUND DIE AND SAID COMPOUND DIE ENTERS SAID SECOND DIE TO BLANK AND PUNCH AN ANNULAR STAMPING FROM A PIECE OF STOCK ALONG THE INNER AND OUTER EDGES OF SAID COMPOUNG DIE, AN ANNULAR STAMPING KNOCKOUT SURROUNDING SAID PUNCH IN THE SPACE BETWEEN SAID OUT SURROUNDING SAID PUNCH IN THE SPACE BETWEEN SAID ABLE RELATIVE TO SAID PUNCH AND SECOND DIE BETWEEN A FORWARD POSITION IN WHICH ITS FRONT END PORJECTS FORWARDLY BEYOND THE FRONT ENDS OF SAID PUNCH AND SECOND DIE AND A REARWARD POSITION IN WHICH ITS FORWARD END IS WITHDRAWN REARWARDLY OF SAID FRONT ENDS, MEANS FOR MOVING SAID KNOCKOUT TO ITS FORWARD POSITION IN RESPONSE TO REARWARD MOVEMENT OF SAID CARRIER, SAID RECESSES IN SAID FICED SUPPORT AND IN SAID RETAINER OPENING FORWARDLY SO THAT SAID COMPOUND DIE AND STRIPPER CAN BE INSTALLED AND REMOVED BY A STRAIGHT FORWARD OR REARWARD MOVEMENT, THE RECESS IN SAID CARRIER OPENING REARWARDLY TO THAT SAID SECOND DIE AND PUNCH CAN BE INSTALLED AND REMOVED BY A STRAIGHT FORWARD OR REARWARD MOVEMENT, QUICK-RELEASE LOCKING MEMBERS FOR RELEASABLY LOCKING SAID COMPOUND DIE, STRIPPER, SECOND DIE AND PUNCH IN THEIR RECESSES, SAID MEANS FOR MOVING SAID KNOCKOUT OT ITS FORWARD POSITION INCLUDING AN AXIALLY SLIDABLE MEMBER ON SAID CARRIER HAVING MEANS AT THE FRON TEND ENGAGEABLE WITH SAID KNOCKOUT UPON FORWARD MOVEMENT THEREOF RELATIVE TO SAID CARRIER TO ADVANCE SAID KNOCKOUT OT ITS FORWARD LIMIT, AN ADJUSTABLE STOP FIXED ON SAID FRAME AND ENGAGEABLE WITH SAID MEMBER UPON REARWARD MOVEMENT OF SAID CARRIER TO MOVE SAID MEMBER FORWARDLY RELATIVE TO SAID CARRIER, SAID CARRIER HAVING PASSAGE THEREIN EXTENDING FROM THE REAR END THEREOF FORWARDLY TOT HE CARRIER RECESS AND RESPECTIVELY ALIGNED WITH SAID SECOND DIE AND SAID PUNCH, KNOCKOUT PINS SLIDABLE IN SAID PASSAGES, SAID ADJUSTABLE STOP BEING FORMED TO CLEAR SAID PINS IN ONE POSITION OF ADJUSTMENT FURING REARWARD MOVEMENT OF SAID CARRIER AND TO ENGAGE SAID PINS UPON REARWARD MOVEMENT OF SAID CARRIER IN ANOTHER POSITION OF ADJUSTMENT TO REMOVE THE SECOND DIE AND PUNCH BY THE ACTION OF SAID PINS, AND MEANS FOR LOCKIN SAID STOP IN ADJUSTED POSITIONS.