US2160676A

US2160676A - Combined punch and stripper

Info

Publication number: US2160676A
Application number: US179529A
Authority: US
Inventors: Clement C Richard
Original assignee: Allied Products Corp
Current assignee: Allied Products Corp
Priority date: 1937-12-13
Filing date: 1937-12-13
Publication date: 1939-05-30
Anticipated expiration: 1956-05-30

Description

May 30, 1939.

QC. RICHARD COMBINED PUNCH AND STRIPPER Filed Dec. 13, 1957 I INVENTOIR. 6161276272 C'fiz'ciard' ATTORNEY.

Patented May 30. 1939 UNITED STATES 2,160,876 COMBINED PUNCH AND S'IRI'PPIJR.v

Clement C. Richard, Bloomfield Hills, Mlch., as

signorto Allied Products Corporation, Detroit,

Mich, a corporation of Michigan Application December 13, 1937', Serial No. 119.529

7 Claims.

3 This invention relates to a punch and companion stripper, the object being to provide a punch which carries its own stripper plate or button so that in a group of punches for instance, instead of having an apertured plate common tothe group and supported by the'head of the-,press'with'which the punch set is associated, each punch carries its own stripper and thus the punches may be readily removed from the retainer without disturbing the remainder projecting the stripper carried by the punch and" independently engageable with the face of the .retainer in which the punch is held, the arrangement being such that movement of the punch due to'wear does not aifect the seating ofthe stripper against the retainer face.

It is further an object and feature of the in- 30 vention to provide a retainer in which the punch is automatically locked in position in the retainer body, the punch havinga recess in its shank and the lock comprising a spring-pressed ball or the equivalent feeding into the recess andautomati- 35 cally taking up wear as the punch head and backing-plate become worn with which is associated acoiledspring encircling the punch and a stripper button riding'on the punch point and secured to the outer end of the spring, the punch shank having a notch to receive aninbent portion of the opposite end of the spring, the notch being of greater width longitudinally of the punch than the portion of the spring positioned therein pros viding for longitudinal displacement of the punch 4:, without displacement of the-spring end from"the notch through its pressure engagement with the face of theretainer.

These various objects and'novel features of the invention are hereinafter more fully de- 5 scribed and claimed, and the preferred form of construction of a unitary punch and stripper elementembodying my invention is shown in the accompanying drawing in which v Fig. 1 is a longitudinal section of a punch and as stripper my invention.

the head of the press (not here shown).

' Fig; 2 is a similar section taken on line 2-2 of Fig. 1. r

Fig. 3 is a section taken through the retainer body and lock element on line 3-3 of Fig. l. Fig. 4 is a section taken through the punch on line H of Fig.1 showing the notch and indented spring seated therein.-

Fig. 5 is a section taken on line 55 'of Fig. 1 further illustrating 'the'manner of attachment of the stripper plate or button to the spring. 1

It has been common heretofore, as above stated, to provide a stripper plate having apertures for the several punches of a group, which fatter is spring-supported relative to the head of the press and mounted independently of the punches. 16

Such previous construction becomes cumbersome in use due to the fact that if a punch is broken the stripper plate must of necessity be dismounted in 'order to remove the shank of a broken punch.

' The punch retainer of" this present invention 20 which is indicated at l, is of the same general character as shown in United States Patent No. 1,621,811 of March 22, 1927, issued to O. K. Richard and C. C. Richard. In this present case-a ball 2 is used riding in an'arigularly disposed aperture 3 in the retainer body which aperture opens into the aperture 4 for the punch shank. 'There is also an aperture 5 from the bottom of the ball recess through the face of the retainer.

This is provided to permitan instrument to be inserted to engagement with the ball to retract the same to thereby permit-ready withdrawal of the punch.-

There is provided theusual backing plate 6 to which the retainer body is secured as by screws inserted through the apertures in the retainer and b'ackingplate to secure the punch head to It will be noted that the "shank of the punch 'has an inclined recess 8 as in the former patent mentioned, and the relationship of the lock and the recess 8 here shown is of the same character and for the same purpose as inthe said United'States patent; I

I have thus described the retainers, the locking element, and the operation thereof for the reason that it is with such a structure that my punch and stripper unit is particularly useful. Punches frequently have to be withdrawn and new punches set in place but, by my improved construction and arrangement of the stripper and its spring as hereinafter described, the punch and stripper are .as readily manipulated as the punch alone, no extra labor being involvedon the part of the operator and avoiding not only,

in assembled relation, the punch andstripper the cost but the loss of time incident to the assembly or removal of the prior forms of stripper plates with the punch head every time it became necessary to remove a punch from the head.

The stripper consists of what I will term a button I0 which may be of circular form having a hub II with an opening I2 therein for the punch point I3. This aperture I! has a coned ables the button to be threaded onto the spring with the indentation engaging the upper face of a second turn of the spring as indicated in Fig.

-1. When the button is turned sufliciently tightly, compression of the first coil relative to the second coil of the spring isproduced' which holds the button in place by tension. Other means may be provided for attaching the button to the spring but the above described means is of simple character and in the case of damage to a button'permits its ready removal and substitution of a new one. l

The face of the punch shank is provided with a notch II of arcuate form as will be understood from Fig. 4 and the end of the spring is inbent at l8 to enter this arcuate notch ll. of the notch longitudinally of the punch is greater than the width of the indented spring end. Thus the said spring end and in fact the spring itself may be freely moved longitudinally of the punch to the extent permitted by the width of the notch.

when the punch is seated in its retainer, the

notch H has an upper edge within the recess for the punch shank in the retainer and thus permits the spring end to seat against the face of the retainer as will be readily understood from Fig. 2. The pressure of compression of the spring caused by the punch pasing through a plated! for instance as shown in Fig. 1 will be received by the face of theretainer and is not taken by the punch. Normally the spring, is of such length that the stripper plate It) has its lower face below the tip of the punch and thus. upon the punch entering the plate l9 the spring I 6' is compressed and upon withdrawal of the punch in the formed aperture of the plate, the button will be projected to strip the work I! from the punch end. The operation of the stripper is entirely automatic once the punch has been set in the retainer and the punch simply carries the stripper and its spring and supports the stripper property in relation to' the punch yet in the case of breakage is readily removable from the punch. When the punch, stripperand its sp ring are its place due to the retainer constructionas well as the unitary punch and stripperstructure.

It is to be noted that the punch is held from rotation by the lock ball or element 2 as the notch 8 in the punch shank for the ba1l..is' of arcuate form -fitting the ball as shown in-Fi g.'3;

' one end attached to the stripper plate andthe 'Oth8l end supported-by the punch shank, the said support on the shank permitting a limited longito therebyhold the same from rotation.

The retainer block is here shown as carryin only a single punch but the blockmay be pro The width vided with several punch apertures and punch locking elements of the character here shown and as is my common practice. The invention is not restricted however to the-specific form of retainer shown as other forms constructed to,.

permit ready insertion or removal of the punches may be utilized.

It is believed evident from the foregoing de-' scription, that the various objects and features of the invention are attained by the construction described; that a new facility in the handling of punches and stripper plates is provided by providing a punch and stripper unit wherein the punch carries its own stripper and thus providing a mode of use in insertion .or removal from retainers carried by the punch head which is of particular benefit where several punches are used in a group.

Having thus fully described my invention, its

utility and mode of operation, what I claim and desire to secure by'Letters Patent of the United States is:

l. A- combined punch and stripper comprising a punch having a shank and a point, a stripper plate apertured to receive the point and reciprocable thereon, and a helical spring encircling the punch and having one end attached to the plate a and the other end to the punch shank, in a man-- ner to permit the said .end to limitedly move longitudinally of the shank.

secured to the stripper plate, the punch shank having an arcuate notch and the end coil of the spring having an arcuate inturned portion engageable in the notch to hold the stripper plate in normal position to a point beyond the punch shank.

3. A combined punch and stripper for associattion with a retainer, comprising a punch having a point and shank, a stripper plate reciprocable on the punch point, and a helical spring encircling the punch and secured to the stripper plate at one end, the opposite end being secured to the punch shank by a lost motion connection whereby on insertion of the punch shank in the retainer therefor the spring end may continuously seat against the retainer face as the punch through wear feeds into the retainer. 4. A combined punch and stripper unit comprising a punch havinga shank and a point, a stripper plate having a hub apertured to receive the point, a helical coiled spring, thestripper plate having'a cylindrical shell spaced from the hub providing a recess for the spring end,.said shell having a part. thereof engageable between the turns of the coil permitting the punch to be turned on the coil to at least a second turn to thereby compress the end-turn and retain the stripper plate thereon by: tension, the other'end of the spring being attached to the punch body. a .5. A combined punch and stripper manipulatable as a unit for insertion in a retainer having an opening through one face thereof, and releasable means for autmnatically locking the punch therein comprising a punch having a point and a shank, the shahk having a part cooperating with the locking means on insertion in the retainer, a stripper plate reciprocably mounted on the punch point, and a helical spring having tudinal movement of the spring on the pimch whereby as the stripper plate engages the work and compresses the spring,.the pressure is taken by the face of the retainer.

6. A unitary punch and stripper assembly for the shank is inserted therein, a helical spring into which the punch shank is inserted, the end of the spring seating in the notch in a manner to slide longitudinally oi. the punch within the limits ofthe notch, and a stripper button carried by the opposite end of th spring, said button being apertured to receive t e punch point, the

connection between the'spring and the punch shank compensating for wear on the end of the punch permitting the same to feed into the retainer.

'1; In combination, a retainer having an aperture for a punch shank, a releasable lock element for holding the punch in place, a punch having a shank insertible in the aperture and formed forv cooperative relation with the lock, a stripper comprising a plate reciprocable on the punch point, 1

said plate having a cylindrical recess and a spring having one end engageable in the recess and attached to the plate and the other end attached to the punch shank, the arrangement providing for removal of the punch and strippervas a unit 15 from the retainer by release 01 the lock.

' CLEMENT c