US3114280A

US3114280A - Punching device

Info

Publication number: US3114280A
Application number: US75771A
Authority: US
Inventors: Arthur K Schott
Original assignee: Houdaille Industries Inc
Current assignee: Houdaille Industries Inc
Priority date: 1960-12-14
Filing date: 1960-12-14
Publication date: 1963-12-17
Anticipated expiration: 1980-12-17

Description

Dec. 17, 1963 A. K. scHoTT 3,114,280 V PUNCHING DEVICE Filed Deo. 14, 1960 A TTORNE YS United States Patent O 3,114,280 PUNCHING DEVICE Arthur K. Schott, Kenmore, N .Y., assignor to Houdaille Industries, Inc., Buffalo, N.Y., a corporation of Michigan Filed Dec. 14, 1960, Ser. No. 75,771 3 Claims. (Cl. 815-140) This invention relates generally to punching devices of the unitized or subpress type, and more specifically to improved structure therefor by which larger size perforations may be made than has heretofore been possible with prior punching devices of the `same width.

Although the principles of the present invention may be included in various perforating implements, a particularly useful application is made in perforating implements or devices having a single C-frame rigid holder adapted to reciprocably support a punch and stripping assembly in its upper arm, and adapted to support a die in its lower arm, and to receive a workpiece therebetween for perforation. In devices of this type, the punching and stripping assembly is reciprocably supported in the upper arm and is received therein, a bore or `guide opening being provided therein for such purpose. It will be readily apparent that components which effect stripping and punching will have to share the opening in the arm, so that the maximum punch size that can be accommodated will be somewhat -smaller than the opening therein.

The present invention contemplates a novel arrangement of components to support the punch and to support the die so that the size of punch and die which may be accommodated by a holder of a particular width will be somewhat larger than those previously known in the art.

Accordingly, it is an object of the present invention to provide an improved perforating implement of the unitized or subpress type.

Another object of the present invention is to provide a punching device of the low or 'short profile type, which device is adapted to receive, support, and guide punching elements of a larger hole-punching size than has previously been possible for a given width of holder.

Yet another object of the present invention is to provide a punching and stripping assembly. comprising components so arranged as to accommodate relatively large size punches.

A still further object of the present invention is to provide means for supporting a die in a simplified accurate manner.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheet of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

n the drawings:

FIGURE 1 is a side elevational vie-w, partly in crosssection, of a punching device provided in accordance with the principles of the present invention;

FIGURE 2 is a cross-sectional view taken along line ll-II of FIGURE 1; and

FIGURE 3 is a cross-sectional view corresponding broadly to FIGURE 2 in orientation, and lshowing a prior art structure for purposes of comparison.

As shown on the drawings:

The principles of this invention are particularly useful when embodied in a perforating implement or hole punching device 16 of 4the self-contained or unitized type of punching apparatus, such as illustrated in FIGURE 1. The punching device 16 includes a holder 11 of the C-frame type, having an upper arm 11a and a lower arm 3,114,280 Patented Dec. 17, 1963 11b, respectively adapted to support a punching and stripping assembly 12 and a die 13.

The holder 11 is provided with a unitary cylindrical surface 14 in its upper rigid arm 11a, the cylindrical surface 14 defining a unitary bore or guide opening 15 Within which the punching and stripping assembly 12 is slidably and reciprocably guided and supported.

The punching and stripping assembly 12 includes a stripper sleeve or guiding and stripping sleeve 16, a punch 17, and a stripper spring 18. The guiding and stripping sleeve 16 is disposed at the lower end of the bore 1S and is guided directly thereby, the -sleeve 16 being normally disposed entirely Within the bore 15. At the upper end of the sleeve 16, there is a smaller internal diameter 19 which is substantially concentrically arranged with a larger internal diameter 20. Intermediate said larger and smaller

internal diameters

19 and 20, there is provided an internal downwardly directed shoulder 21 which is nearer to the upper end of the sleeve 16 than it is to the lower end. The punch 17 includes a head 22, a shank 23, and a punch bit 24. The head 22 is directly guided at its outer diameter by the upper end of the bore 15, the upper or distal end of the head 22 being adapted to be engaged by a press ram. The head 22 is rigidly secured to the shank 23, a setscrew or lockscrew and groove arrangement 25 being provided in the illustrated embodiment for this purpose. The head 22 is provided with a downwardly directed shoulder 26 which abuts a confronting shoulder on the shank 23 so that the fastening means 25 is not employed to transmit punching forces to the punch bit 24. The shank 23 extends coaxially into the sleeve 16, comprises a cylindrical configuration, and is integral with the punch bit 24'. However, it will be noted that the shank 23 is of a diameter less than that of the punch bit, and that it extends through the opening defined by the smaller diameter 19 in the sleeve 16. The punch bit 24 is normally disposed entirely 'within the sleeve 16, and therefore has a shorter length than the sleeve in a direction parallel to their axes. The punch bit includes an enlargement 27 at its upper end which always is disposed within the sleeve 16 and which is guided directly thereby at said larger internal diameter 2d. Between the shank 23 and the punch bit 24 there is therefore provided an upwardly directed shoulder 28 which normally abuts the downwardly directed shoulder 21. The eniargement 27' is the largest diameter throughout the length of the shank 23 or punch bit 24. The stripping spring 1S is a compression spring which is disposed entirely within the bore 15, it thus being concealed from view and hence protected from interfering or being interfered with. It will be understood that a particular advantage for such spring disposition is that it assists in maintaining the overall height of the device 1% at a minimum. The spring 18 is thus disposed between the confronting lower end of 4the punch head 22 and the upper end of the sleeve 16 to urge the head 22 and sleeve 16 apart. From a radial standpoint, it will be readily understood that the spring is immediately adjacent to the punch shank 23 throughout the spring length, .and immediately adjacent to the cylindrical surface 14.

It will be readily understood that the punching and stripping assembly 12 may be provided with a punch 17 having a punch bit 24, the lower end of which is shaped to provide a cutting edge which is non-circular It is known in the art that Isuch a punch must be provided with means for preventing angular movement thereof about its reciprocation axis. Accordingly, and to this end, the instant device is likewise provided with structure for precluding punch rotation. It will be read-ily understood that such structure may be omitted `where the punch tip is round, as illustrated, and where included as shown,

the punch tip configuration may be altered as may be desired. Accordingly, to provide angular guidance for the punch 17, the sleeve 16 is provided with a first keyway 30 which opens radially outward, and which terminates at 31 at a point which is spaced from the lower end of the sleeve 16. The sleeve 16 is further provided with a second keyway 32 which opens radially inward. The keyways 3?, 32 extend in parallel relation to each other, and are parallel to the axis of the sleeve 16. In combination therewith, there is provided a rst key 33 which is supported by the upper arm 11a, the key 33 extending into the bore and into the first keyway 3). A second key 34 is carried by the enlargement 27 of the punch bit 24 and extends radially therefrom into the second keyway 32. These keys and keyways jointly maintain the angular alignment of the punch 17 with respect to the holder 11. Since the first keyway terminates a spaced distance from the lower end of the sleeve 16, the key 33 also serves to prevent removal of the punching and stripping asembly 12. This keying structure otherwise does not restrict such vertical sliding movement as may be required. The key 33 herein illustrated includes a threaded portion which has a frictional fit with the upper arm 11a, and a liattened inner end which is received directly in the keyway 30. Rotation of the key 33 permits the flats thereon to resigter properly with the keyway 39.

At its lower end, the stripper sleeve 16 is provided with a downwardly directed recess in which a stripper ring 35 is disposed, being held therein by a removable snap ring 36. The Iaperture in the ring 35 conforms to the peripheral configuration at the cutting edge of the punch bit 24, which of course can be considerably smaller than the enlargement 27, and which can be as large as the enlargement 27.

A lifter or lifting spring 37 acts between the upper arm 11 and a snap ring carried by the punch head 22, the lifter spring 37 acting to resiliently support the punching and stripping assembly 12 in a position wherein said assembly is retracted from the die 13 on the lower arm 11b.

The stationary lower arm 11b may also be termed as a base since its lower surface is adapted to be supported either directly on a press bed or on other punch mounting means such as a template which receives a pair of pilot pins 4t), 4h. The lower arm 11b is provided with an upwardly directed block supporting surface 41 within which there is an aperture 42 which communicates with the front of the device 10 for slug ejection. The arm 11b `further includes a first laterally spaced pair of means 43 which respectively extend on opposite sides of the die 13 and which forwardly over the block supporting surface 41. The confronting vertical portions of the means 43 comprise vertically directed means against which the die 13 abuts. The means for supporting the die further includes a die clamping block 44 which has a block base 45 resting on and supported by the block supporting surface 41. The block base 45 has an aperture 46 aligned with the aperture 42. The block 44 also includes a second laterally spaced pair of means 47 corresponding generally to the means 43, the means 47 extending rearwardly in confronting relation to each other and to the die abutment means 43. The means 43, 44 jointly define a recess conforming substantially to the external configuration of the die 13, the die 13 thus being disposed within such recess. A particularly important feature of this invention is that the bottom of this recess is defined solely by the apertured block base 45 of the clamping block 44, and thus the lower surface of the die 13 engages solely with the clamping block 44. In prior art structures, the die has typically, in this type of device, rested upon a surface defined jointly by the base and a clamping block. In such structure, tolerances must be accurately maintained so that the joint supporting surfaces in an actual article lie precisely in the same plane.

4 When that plane is delined by structure which comprises solely a portion of the clamping block, the need for such maintenance of tolerance is obviated, and the likelihood of a slightly cocked die due to non-planar surfaces is eliminated.

To hold the clamping block in the proper clamping relation, there are provided a pair of screws or screw means 5&1 which extend to the rear of the holder and which are threadably received therein. The screw axis is declined slightly so that both a downward and a rearward clamping is simultaneously effected. The axis of each of the screws 50 is disposed between the aperture 46 and the outside Wall of the clamping block 44, and is disposed beneath the die 13. The screw means 50 thus removably secure the block 44 to the lower arm 11b, and clamp the die 13 in a fixed position in alignment with the punch and stripping assembly 12.

The die 13 is thus disposed between the die abutment means 43 and the clamping means 44 and is supported solely on the die supporting portion or block base 45 for vertical support. The die 13 is apertured to conform to the configuration of the cutting edge of the punch bit 24, the aperture therein being aligned with the apertures 42 and 46 for slug ejection.

When this device 1t) is employed, it is -supported between the bed and ram of a press, die support being provided by the lower arm 11b, and punch guidance being provided by the upper arm 11a. When the ram of the press acts on the upper end of the head 22, force is transmitted to the punch hit 24. Upon application of such force, the lifter spring 37 first yields, permitting the punching and stripping assembly 12 to move as a unit until the sleeve 16 engages the workpiece. Thereafter, further depression of the punch by the ram also causes compression of the stripper spring 1S, and causes the punch bit to move through the workpiece into the die 13. Upon release of the punching or ram force, energy stored in the springs 18, 37 is released, energy from the spring 18 first serving to withdraw the punch bit 24 into the sleeve 16, thereby stripping it from the workpiece, and energy from the spring 37 serving to raise the punch and stripping assembly 12 as a unit.

Where the die 13 is provided with a shaped configuration, a key 51 supported by the lower arm and locked in position by a screw 52, serves to prevent rotation of the die 13 by extending into the recess in which the die is disposed and more particularly into a vertical keyway 53 in the die 13. It will be apparent that the punch and stripping assembly 12 may be utilized to align a shaped die 13, the keying for the same being omitted. However, it is known to be convenient to have independent keying for the die 13 so that replacement thereof may be more easily facilitated.

One of the primary advantages of this invention is not readily apparent from an examination of FIGURES 1 and 2, and FIGURE 3 is therefore provided to illustrate and emphasize this advantage. FIGURE 3 represents a prior art structure of a punching and stripping assembly 60 disposed in a holder 61 having a bore 62 identical in diameter to the bore 15. A stripping spring 63 has been provided which is identical in diameter to the stripping spring 1B. A punch 64 has been provided with a head assembly 65 which likewise is slidable directly in the upper end of the bore 62, the punch being guided for reciprocation by a sleeve 66. The stripping spring 63 also acts between a collar 67 on the lower end of the stripping sleeve and the head 65 of the punch. A guide button 63, supported by means obscured in this view, has an internal configuration conforming to the cutting edge of the punch 66, and therefore corresponds broadly to the ring 35. These figures have been so scaled as to represent an actual holder width of one and three-fourths inches, the FIGURE l and 2 structure thus being able to accommodate punches capable of making a hole up to seven-eighths inch diameter, while the prior art structure of FlGURE 3 is capable of accommodating punch structure that will produce a hole no larger than one-half inch diameter. Thus for a punching device of the same holder width, the novel structure of this invention permits the utilization of punch bits which are nearly twice as wide in diameter as that which can be accommodated by the FIGURE 3 structure. It will be noted that in both instances, the stripping springs have been retained completely within the upper arm so that this improvement has been applied to that class of unitized punches which provide a relatively low closed height or shut height.

Other commercial holder widths for this type of device have been sold, and where the instant structure is employed, larger punch sizes may be accommodated without an increase in holder width. The thickness or width of the device at the punching and stripping assembly 12 is the same as its width at the clamping block 44, and is the maximum width of the entire device. Using the above example, it is thus apparent that two seveneighths inch diameter holes may be simultaneously made in a workpiece by two of these devices, and their centers may be as close as the holder width, namely one and three-fourths inches. Where wider holders are employed to malte two holes similar to the above example simultaneously, the holes cannot be located with their centers that close together. Accordingly, under such circumstances, the instant invention enables doing in one operation what previously has required two separate perforating operations.

Although various minor modifications might be suggested by those versed in the art, it should be understood that l wish to embody within the scope of the patent warranted hereon, all such embodiments as reasonably and properly come within the scope of my contribution to the art.

l claim as my invention:

1. in a periorating implement comprising a holder having an upper stationary arm and a lower stationary arm, a punching and stripping assembly slidably supported as a unit in a bore in said upper arm, the improvement of means for supporting a die in alignment with said punching and stripping assembly, comprising in combination therewith: an upwardly directed apertured block-supporting surface on said lower arm; a unitary clamping block having an apertured base carried on said block-supporting surface and an upwardly directed die supporting portion; said lower arm having first laterally spaced means extending forwardly above said die supporting portion of said block integrally and defining vertical die abutment means; said block having second laterally spaced means extending rearwardly in confronting relation to said first laterally spaced means and defining vertical die clamping means; a die disposed intermediate said die abutment and clamping means and resting solely on said die supporting portion of said clamping block, said die having an aperture aligned with said apertures; and means for removably securing said block to said lower arm in die-clamping relation, with said die thereby maintained in alignment with said punching and stripping assembly, said securing means extending beneath said die adjacent to said bloc" aperture.

2. In a perforating implement comprising a holder having an upper stationary arm adapted to slidably support a punching and stripping assembly, and having a lower arm, the improvement of means for supporting a die on said lower arm in alignment with the punching and stripping assembly, comprising in combination: a unitary clamping block removably secured to said lower arm, said clamping block and said lower arm each defining opposite portions of the periphery of a die-receiving recess disposed to support the die in alignment with the punching and stripping assembly, the bottom of said recess comprising solely a portion of said clamping block.

3. In a perforating implement comprising a holder having an upper stationary arm adapted to slidably support a punching and stripping assembly, and having a lower arm, the improvement of means for supporting a die on said lower arm in alignment with the punching and stripping assembly, comprising in combination:

(a) an upwardly directed block-supporting surface delined by said lower arm and disposed beneath the punching and stripping assembly;

(b) vertical die-abutment means integral with said lower arm and overhanging said block-supporting surface and vertically spaced therefrom;

(c) a unitary clamping block supported on said blocksupporting surface, and having an upwardly directed die support surface extending beneath said die-abutment means of said lower arm, and comprising the only die support surface for the die, said block having integral vertical die-abutment means extending upwardly from said die support surface in horizontally spaced confronting relation to said die-abutment means of said arm, and jointly therewith delining a die-receiving recess; and

(d) releasable securing means acting between said block and said lower arm for electing clamping of the die in said recess by the two vertical die-abutment means.

References Cited in the file of this patent UNITED STATES PATENTS 190,683 Jenkins May 15, 1877 1,076,384 Mighirian Oct. 21, 1913 2,013,976 Wales Sept. 10, 1935 2,151,119 Kiwi Mar. 21, 1939 2,317,424 Wales Apr. 27, 1943 2,364,401 Stellin Dec. 5, 1944 2,371,565 Whistler Mar. 13, 1945 2,815,814 Taylor Dec. l0, 1957 2,882,971 Bennett et al. Apr. 2l, 1959 FOREIGN PATENTS 411,077 Germany Mar. 10, 1925 1,135,704 France Dec. 17, 1956

Claims

1. IN A PERFORATING IMPLEMENT COMPRISING A HOLDER HAVING AN UPPER STATIONARY ARM AND A LOWER STATIONARY ARM, A PUNCHING AND STRIPPING ASSEMBLY SLIDABLY SUPPORTED AS A UNIT IN A BORE IN SAID UPPER ARM, THE IMPROVEMENT OF MEANS FOR SUPPORTING A DIE IN ALIGNMENT WITH SAID PUNCHING AND STRIPPING ASSEMBLY, COMPRISING IN COMBINATION THEREWITH: AN UPWARDLY DIRECTED APERTURED BLOCK-SUPPORTING SURFACE ON SAID LOWER ARM; A UNITARY CLAMPING BLOCK HAVING AN APERTURED BASE CARRIED ON SAID BLOCK-SUPPORTING SURFACE AND AN UPWARDLY DIRECTED DIE SUPPORTING PORTION; SAID LOWER ARM HAVING FIRST LATERALLY SPACED MEANS EXTENDING FORWARDLY ABOVE SAID DIE SUPPORTING PORTION OF SAID BLOCK INTEGRALLY AND DEFINING VERTICAL DIE ABUTMENT MEANS; SAID BLOCK HAVING SECOND LATERALLY SPACED MEANS EXTENDING REARWARDLY IN CONFRONTING RELATION TO SAID FIRST LATERALLY SPACED MEANS AND DEFINING VERTICAL DIE CLAMPING MEANS; A DIE DISPOSED INTERMEDIATE SAID DIE ABUTMENT AND CLAMPING MEANS AND RESTING SOLELY ON SAID DIE SUPPORTING PORTION OF SAID CLAMPING BLOCK, SAID DIE HAVING AN APERTURE ALIGNED WITH SAID APERTURES; AND MEANS FOR REMOVABLY SECURING SAID BLOCK TO SAID LOWER ARM IN DIE-CLAMPING RELATION, WITH SAID DIE THEREBY MAINTAINED IN ALIGNMENT WITH SAID PUNCHING AND STRIPPING ASSEMBLY, SAID SECURING MEANS EXTENDING BENEATH SAID DIE ADJACENT TO SAID BLOCK APERTURE.