US3089376A

US3089376A - Magnetic punch holder and die holder assembly

Info

Publication number: US3089376A
Authority: US
Inventors: Lawrence V Whistler; Jr Lawrence V Whistler
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-01-30
Filing date: 1959-01-30
Publication date: 1963-05-14
Anticipated expiration: 1980-05-14

Description

y 1963 L. v. WHISTLER ET AL 3,089,376

MAGNETIC PUNCH HOLDER AND DIE HOLDER ASSEMBLY 2 Sheets-Sheet 1 Filed Jan. 50, 1959 INVENTORS LawrenceVWhistler,Sr.

W d. m W V w P n m WM ATTORNEYS y 1963 L. v. WHISTLER ETAL 3,089,376

MAGNETIC PUNCH HOLDER AND DIE HOLDER ASSEMBLY 2 Sheets-Sheet 3 Filed Jan. 30, 1959 FIG. 2.

T INVENTORS Lawrence\/.Whisfler,8r. Lawrence V.Whisfler,Jr.

BY gm 9W 6 7 7 l |\|1 5 7 l| I i H M WM 7 l 2 8 8 4 w J 8 H G y/ 1 l w 3 N F .l 8 9 8 ATTORNEYj United States Patent 3,089,376 MAGNETKC PUNQH HOLDER AND DIE HOLDER ASSEMBLY Lawrence V. Whistler, 259 Doncaster Road, and Lawrence V. Whistler, Jr., 251l Doncaster Road, both of Kenmore, NFL

Filed Jan. 30, 1959, Ser. No. 7%,l3t57 14 Claims. (Cl. 83619) The present invention relates to a new and novel punch and die assembly, and more particularly to a punch and die assembly adapted to perforate sheet metal and other sheet material.

It has long been a practice in the art to mount punch and die holders in place within a die-set by means of bolts or other separate fastening means which required the formation of holes or slots in the various components, and additionally required a relatively large amount of time in assembling. Furthermore, with this type of an arrangement, quite a bit of difficulty is encountered in properly locating the punches and dies such that they they are truly concentric with one another.

As a consequence of the problems encountered with the utilization of the above-described type of punch and die holders, magnetic punch and die holders have been developed such as shown in U .8. Patent 2,364,834, wherein the punch and die holders are provided with permanent magnets for adhering the holders to suitable mounting members. The present invention is an improvement over the type of structure as shown in the aforementioned patent. Magnetic type punch and die holders have proved to be quite satisfactory in operation, but due to the size of the assemblies, the number of holes which can be punched in a given area of a workpiece is limited, as only a certain number of punch and die holders can be assembled in a given area.

It is accordingly a primary objective of the present invention to provide a much more compact punch and die assembly wherein the punch holders and die holders according to the present invention occupy a minimum of space and can be assembled closely adjacent one another in order to provide a relatively large number of punched openings in a small area of a workpiece.

While the bulk of the punch and die holders has been greatly reduced in the present invention, the numerous advantages provided with magnetic type punch and die holders are retained. For example, the punch and die holders may be quickly and easily replaced or interchanged, and all punch and die parts may be removed and reused on diiferent jobs. Of course, the templets employed in the apparatus will vary, and the templets themselves can be restored and reused as required.

In the structure according to the present invention, means is provided for supporting a punch templet and a die templet adjacent the punch shoe and die shoe respectively of the die-set. The novel punch retainer according to the present invention comprises a body portion of substantially circular cross-section having a reduced collar at one end portion and a groove in the outer surface of the opposite end portion thereof. Inner and outer magnetic insulating sleeves are disposed in the groove of the punch holder, and a substantially annular permanent magnet is disposed between the sleeves. A substantially annular core member is supported between the sleeves and in abutting relationship with the magnet, the inner insulating sleeve having the outer portion thereof turned over so as to engage the core and maintain the core and magnet in operative position.

The structure of the punch holder is very compact, providing a very effective magnetic field which securely retains the punch holder in operative position, and permit- 3,089,376 Patented May 14, 1963 ting a relatively large number of punch holders to be assembled in closely adjacent relationship.

The novel die holder according to the present invention includes a body having a central opening in the upper surface thereof for receiving a die bushing, and a lateral passage is formed in the body of the die holder for allowing slugs to pass outwardly from the die holder when the slugs are punched from a workpiece.

In order to assure proper alignment of the punch and die holders during operation, a means is provided for preventing turning movement of the die holder. This means comprises a pin having a sharpened upper edge portion, the pin being slidably disposed within an opening formed in the upper surface of the die holder. The pin is resiliently urged in an upward direction such as the sharpened upper end portion thereof engages the under surface of a die templet supported adjacent the die shoe. A die bushing is mounted within the central opening in the die holder, this die bushing being received within a complementary opening formed in the die templet. The engagement of the die templet with the die bushing, and the cooperating engagement of the pin within the die holder against the under surface of the die templet effectively prevents turning movement of the die holder during operation of the apparatus. It is apparent that in this manner a very simple and compact structure is provided for positively preventing rotation of the die holders.

The die templet is provided with a plurality of solid gauges and resilient spring gauges for engaging a workpiece and retaining the workpiece in proper operative position during the punching operation. A suitable stripper means is also mounted about the punch of the apparatus for stripping the workpiece away from the punches in a well-known manner.

The punch and die holders can readily be adjusted to any desired position on the punch and die shoes, and the punch and die templets employed there-with serve to positively position the punch and die hoiders in position for any particular job. The present invention is described in connection with a die-set having two guide posts, but it is apparent that it may also be employed with die-sets having four guide posts and the punch and die assembly may be employed in any die-set and also may be used directly in a press. It should also be noted that the invention is not limited to perforating devices since it may as well be embodied in punches and dies employed for blank-stamping, forming or other purposes, and accordingly, the term punch and die assembly as employed in the claims includes the male and female elements of stamping devices as well as perforating devices.

In addition, it is evident that in certmn cases only a relatively small number of punches and dies need be changed from job to job, and consequently such punches and dies as are known to be retained in unchanged positions may be permanently mounted in such positions by means of bolts and the like such that only the remaining punches and dies need be changed from time to time. It is of course evident that no special training or tools are required for assembling and dis-sassembling the punch and die holders according to the present invention.

An object of the present invention is to provide a new and novel punch and die assembly employing punch and die holders which may be quickly and easily assembled and disassembled, and which occupy a minimum of space thereby permitting a relatively large number of openings to be formed in a given area of a workpiece.

Another object of the invention is to provide a punch and die assembly wherein precision of hole centers is assured and no special training or tools are required to assemble and disassemble the apparatus.

A further object of the invention is the provision of a punch holder which is compact, wherein a permanent magnet is mounted without the necessity of forming any holes through the magnet for providing external means such as bolts for mounting the magnet in operative position thereby maintaining maximum efiectiveness of the magnet.

A still further object of the invention is to provide a compact die holder including means for positively preventing turning of the die holder during operation of the apparatus.

Yet another object of the invention is the provision of a new and novel punch and die assembly which is quite simple and inexpensive in construction and yet which is sturdy and reliable in operation.

Other objects and many attendant advantages of the invention will become more apparent when considered in connection with the specification and accompanying drawings, wherein:

FIG. 1 is a longitudinal section of the punch and die assembly according to the present invention;

FIG. 2 is a top view of the device shown in FIG. 1 with the punch shoe and associated components removed;

FIG. 3 is an end view of the punch retainer according to the present invention;

FIG. 4 is a sectional view taken along line 44 of FIG. 3 looking in the direction of the arrows;

FIG. 5 is a sectional view of a die holder according to the present invention; and

FIG. 6 is a side view of the die holder shown in FIG. 5.

Referring now to lhe drawings wherein like reference characters designate corresponding parts throughout the several views, there is shown in FIGS. 1 and 2 a die shoe it having an upper surface 11, and four spaced die

templet support posts

12, 13, 14- and 15 which extend upwardly from surfacell. A pair of guide posts 2b and 21 are provided with enlarged

base portions

20 and 21, the enlarged base portions being mounted within complementary openings formed in the die shoe and the guide posts extending upwardly from surface 11 of the die shoe. For clarity of illustration, support post 12 has been removed in FIG. 1 to more clearly illustrate the construction of guide post 20 and its enlarged base portion 20'.

A punch shoe 25 is spaced above die shoe 1th and is provided with four similar downwardly extending punch templet support posts 26, only two of which are visible in FIG. 1, punch templet support posts 26 being spaced similarly to support posts 1245 of the die shoe such that the punch templet support posts are normally positioned above the die templet support posts. A pair of downward-1y extending guide post bushings 34 includes a base portion 30 extending upwardly into a complementary opening formed in the punch shoe for rigidly supporting the guide post bushings from the punch shoe. Each of the guide post bushings 30 is provided with a longitudinally extending opening 31 therein which snugly receives the guide posts 20 such that the punch shoe is properly guided in its movement relative to the die shoe during operation of the apparatus.

A punch templet 35 is provided with a plurality of openings therein in accordance with the particular job and the desired number of punches to be positioned, two openings 36 being illustrated. The punch templet is also provided with four spaced openings 37, only two of which are seen in FIG. 1, each of the punch templet support posts 26 being provided with openings 38 therein adapted to be aligned with openings 37. Templet clamp screws 39 include an upwardly extending threaded shank portion 49, shank portion 40 extending through openings 37 and being threaded within openings 38 in the punch templet support posts for supporting templet 35 is position on the punch templet support posts. A shoulder may be provided on each of the punch templet support posts, if desired, and a cooperating depression formed in the upper surface of the punch templet for aligning the punch templet.

Die templet 45 is provided with a plurality of openings 46 therein, openings 46 being concentric with the openings 36 in the punch templet for positioning the die holders in concentric relation with the punch holders. Die templet is provided with four spaced openings 47 therein, only two of the openings being visible in FIG. 1, it being clear that openings 47 are so spaced from one another that they are adapted to be aligned with openings 48 formed in each of the die templet support posts 12 15. A plurality of templet clamp screws 51 are provided, each of the clamp screws having a threaded shank portion 51 which extends through openings 47 in the die templet and are threaded within correspondingly threaded openings 48 in the die templet support posts. In this manner the die templet is mounted in operative position on the support posts, and in addition, a shoulder may be provided on the support posts for engaging a cooperating depression formed in the die templet for more positively aligning the die templet on the associated support posts, if desired. It is evident that the punch and die templets may be quickly and easily mounted upon or removed from the associated support posts as desired.

The upper surface 55 of the die templet is preferably provided with means for positively positioning a workpiece in the apparatus, this positioning means taking the form of three solid gaugemembers 56 spaced about the templet, and three resilient spring gauges 57, the

gauges

56 and 57 being spaced from one another so as to engage all four sides of a workpiece indicated by reference numeral 60. Each of solid gauges 56 is substantially cylindrical in configuration, being provided with a central threaded opening 61 in the lower surface thereof. Bolt members 62 extend through openings 63 provided in the die templet, bolt members 62 being threaded into opening 61 in solid gauges 56 for rigidly mounting the solid gauges in position on the die templet. Each of the spring gauges 57 includes a base portion 65 which is secured to the upper surface of the die templet by means of bolts 66 threaded into suitable openings provided in the die templet, the spring gauges each comprising an inverted U-shaped portion e7, one leg of which is adapted to engage the side edge of the workpiece, and a laterally projecting flange 68 is provided in the outer end portion of the spring gauges.

It is evident that the workpiece is seated against each of the solid gauges 56 and is resiliently held in operative position by spring gauges 57 which urge the workpiece toward the solid gauges.

Referring now to FIGS. 3 and 4 of the drawings, the novel punch holder according to the present invention is illustrated and comprises a body portion 70 having a substantially annular collar 71 of reduced diameter formed at one end portion thereof and a groove 72. formed in the outer surface of the opposite end portion thereof. Collar 71 is ground within plus or minus of an inch so as to be interchangeable and located concentrically in various templets employed therewith such that the punch holder will be very accurately located relative to the templet which has the openings therein ground to the same tolerance. A central opening 75 is formed in the body and opens at the lower surface 76 of the punch holder. Opening 75 is also ground within 4 of an inch whereby all punches of like diameter are interchangeable in a punch holder, and additionally the accurate formation of annular collar 71 and opening 75 insures that the portions inserted within opening 75 are concentric with collar 71 and the associated opening in the templet. A reduced opening 77 is formed through the central portion of. the opposite end portion of the body and is in communication with opening 75. An obliquely extending threaded opening 78 is provided in the side portion of the body means and opens obliquely into opening 75, opening 78 being adapted to receive a set screw as hereinafter described.

An inner magnetic insulating sleeve 89 is mounted on the inner portion of groove 72 and is formed of a suitable substance such as brass, aluminum or other material which is non-magnetic, whereas the body portion 70 of the punch holder is formed of a good magnetic conductor such as an alloy steel or the like and of a material that can be hardened throughout the entire body and still have a great amount of impact strength to withstand the constant pounding of the head of a punch inserted within the circular opening 75. In order to retain sleeve 80 firmly in position within groove 72, two circumferentially extending depressions 81 and 32 are provided around the upper end portion of the body, sleeve 81} including

deformed portions

83 and 84 seated in

grooves

31 and 82 respectively. The upper end 35 of inner sleeve 80 is spun or flanged over for a purpose hereinafter described.

A permanent magnet 90 of substantially annular configuration is disposed in surrounding relationship to inner sleeve 81 the magnet being of a relatively powerful permanent type such as a magnet identified as Alnico No. 5. An outer magnetic shielding sleeve 91 is disposed in surrounding relationship to magnet 90 and is substantially flush with the outer surface of body 70. It is evident that magnet 90 is retained in operative position between

sleeves

80 and 91.

A core member 92 formed of a suitable magnetically conducted substance such as cold rolled steel is of substantially annular configuration and is disposed between sleeves and 91 and abuts the upper end portion of magnet We Core 92 is provided with a circumferentially extending groove h? formed on the upper inner surface thereof for receiving the turned-over end portion 35 of sleeve titl. It is evident that the aforedescribed structure is such that the turned-over end portion 85 of sleeve 80 retains the core member 9% in abutting relationship with magnet and urges the magnet into tight contact with body portion 7%.

The structure of the punch holder is such that it is extremely compact and occupies a minimum of space, and yet an effectively magnetic field is provided as indicated by lines d5, the insulating sleeves 8d and 91 serving to control the extent of the magnet field and direct the magnetic field such that a firm magnetic adhesion will be provided between the punch holder and the adjacent punch shoe.

Referring now to FIG. 1, two similar punch holders are indicated in operative position on the punch shoe, a set screw 1% being mounted within each of openings 73 in the punch holders and engaging a suitable cooperat ing opening provided in the upper end portion of a punch 101 mounted within openings "75 of the punch holders. Openings 77 formed in the upper portion of the punch holders serve as an air vent when inserting the punches in the associated punch holders for facilitating such insertion. It is apparent that collar portions 71 of the punch holders are received within the cooperating openings 36 formed in the punch templet 35. Each of the punches is provided with a stripper device indicated generally by reference numeral 105, the stripper device comprising a relatively thick header 106 secured to the punch by means of a set screw 167 which is seated within a cooperating groove ld? formed in the punches. A shoe 109 has an opening 116 formed in the central portion thereof receiving a lower end portion of the punch which slidably extends through opening 110. Guide pins 111 are secured to each of the shoes at the four corners thereof and are guided for movement in guide openings 112 formed in header 1%. Head portions i113 are provided on the upper ends of guide pins 111 for preventing excessive downward movement of the shoe 169 under the influence of compression springs 115 surrounding the guide pins and normally urging the shoes in a downward direction. It is apparent that the strippers 105 serve to strip the workpiece from the punches in a conventional manner.

Referring now to FIGS. and 6 of the drawings, the novel die holder according to the present invention is illustrated and comprises a body 120 of substantially circular cross-section, the body having a central socket or opening 121 formed in the upper surface thereof for receiving a die bushing. An obliquely extending threaded opening 122 is in communication with the lower portion of opening 121, and is adapted to receive a set screw for a purpose hereinafter described. The lower portion of opening 121 is in communication with a central opening 123 of reduced diameter which in turn communicates with a laterally extending passage 124 which opens at 125 in the lateral portion of the die holder. Opening 124 is adapted to receive and guide slugs outwardly of the die holder when such slugs have been punched from a piece of associated work material.

The die holder according to the present invention is preferably made of a substance such as alloy steel which is hardened to withstand the wear and tear in use, the opening 121 in the upper surface thereof being ground to a diameter of plus or minus of an inch. The accurate dimensioning of opening 121 is important in order to enable various die bushings to be inserted therein and accurately located with respect to the die holder.

A downwardly projecting opening is provided in the upper surface of the die holder, a pin 1-31 being slidably mounted within opening 130. Pin 13-1 is provided with a sharpened upper end portion 132, the pin being of a hardened metallic material such that the upper end portion is adapted to securely engage the under surface of the associated die templet.

A resilient compression spring is disposed within opening 1 3i} and engages the under surface of enlarged head portion 136 of pin 131 for continuously urging the pin in an upward direction. A substantially cylindrical sleeve 137 formed of suitable material such as brass is provided with threads on the outer surface thereof, and

is threadedly mounted within a suitable threaded upper portion of opening 131 It is apparent that sleeve portion 137 limits upward movement of the pin 1131.

Referring now to FIG. 1 of the drawing, die bushings 1 th are shown as being received within sockets 121 of the die holders, the bushings being provided with a suitable indented portion receiving the inner ends of set screws 14-1 for retaining the die bushing in operative position. The die bushings have a central opening 142 formed in the upper surface thereof and are adapted to receive the end portions of the associated punches. An opening 146 is formed in the die bushings below opening 1 12 and in communication therewith so as to conduct the slugs from the workpiece downwardly into the die holder. The die bushings are also provided with circumferentially extending grooves 145 therein which are adapted to receive snap rings 11% therein, only one snap ring being illustrated in the drawings. The outside diameter of die bushing 140 as well as the inner diameter of the openings in the associated templet are also properly ground to within plus or minus of an inch in order to insure accurate alignment of the die bushing, and, of course, the inner diameter of opening 142 is also accurately ground in order to properly receive the punch therein.

The proper alignment of the punch and die bushing as obtained in the present invention is quite important since experience has shown that when a punch enters a die bushing concentrically with the proper amount of uniform die clearance as predetermined for the material being punched, the useful life of the punch and die is increased by two or three times that which is obtained if there is some slight eccentricity or less clearance on one side of the punch and die bushing during the punching operations.

The purpose of the snap rings in cooperation with the die bushings is to maintain the die bushings and associated die holders in position on the die templet when assembling the apparatus such that the die bushings and die holders may be attached to the templets at a remote position and then assembled in position. as shown in the drawaoeaeve ings. Of course, it is possible to assemble the apparatus without utilizing the snap rings, but this is a rather impractical arrangement. The snap rings can be removed after the die templet is in assembled position as shown.

It is apparent that when in the assembled position as shown in FIG. 1, the sharpened upper end portions of the hardened pins engage the under surface of the die templet, and since the die bushings are snugly received Within openings 46 of the die templet, the interaction of the pins and the die bushings in engagement with the die templet is such that the die holders are positively prevented from rotating with respect to the die templet during operation. When it is desired to operate the apparatus, the proper punch and die templets are selected, and these templets are mounted upon the punch and die shoes respectively by means of the templet clamping screws 39 and 50. The die holders can, of course, be assembled along with the die templet by connecting the die holders to the templet through the intermediary of the snap rings 146. When in assembled position, the punch holders are retained in operative position by means of the permanent magnets 90, and the die holders are retained in operative position and prevented from rotating with respect to the die templet by means of pins 131 which engage the under surface of the templet in cooperation with the engagement between the die templet and the die bushings.

The workpiece is mounted above the die templet and properly positioned by means of the solid gauges 56 and the spring gauges 57, the under surface of the workpiece resting upon the upper surface of the die bushings. FIG. 1 illustrates the punches in position after having punched out slugs from the workpiece, these slugs being indicated by reference numeral 156. The slugs drop downwardly through the interior of the die holders and outwardly therefrom through passages 124.

While only two punch holders and die holders have been illustrated in FIG. 1 of the drawings, a plurality of die holders are illustrated in FIG. 2 for the purpose of illustrating the manner in which the punch or die holders may be grouped together in order to provide a plurality of closely spaced openings in a workpiece. Since the outer diameters of the punch holders and die holders are substantially the same, the grouping of the punch holders will be the same as that of the die holders illustrated in FIG. 2.

As seen in FIG. 2, a first grouping of die holders indicated by reference numeral 155 comprises siX individual die holders disposed in abutting relationship with one another. Such a grouping obviously permits the punch and die holders to ,be very closely arranged, this particular arrangement occupying approximately the same space as two punch and die holders as previously employed in the art. A second group of die holders indicated generally by reference numeral 156 comprises a group of eight individual die holders which are disposed in abutting relationship with one another. This particular arrangement occupies approximately the same space as required by three punch or die holders employed previously. It is apparent from an inspection of the grouping of holders shown in FIG. 2 that a substantially greater number of holes may be punched in a given area in a workpiece when utilizing the arrangement according to the present invention.

While the punch holder illustrated herein is considered the preferabl arrangement, it is also possible to mount the magnet in position by means of a plurality of screws which can extend through aligned openings in the core member, the magnet and into the body of the punch holder. In this case, it would not be necessary to turn over the upper end portion of the inner sleeve. It should, however, be noted that the arrangement as illustrated particularly in FIG. 4 is highly advantageous since no grooves or holes need be provided in the permanent magnet, thereby providing a magnetic field of maximum force.

It is apparent from the foregoing that there is provided a new and novel punch and die assembly employing a very compact arrangement which permits a maximum number of holes to be punched in a given area in a workpiece. The arrangement of the present invention permits precision operations wherein the punch and die bushings will be accurately concentrically aligned with one another. No special training or tools are necessary for successfully employing the present invention. The novel punch holder of the present invention is especially note-worthy in that it is of relatively small and compact size, and yet provides a very efiicient mounting for a punch and also provides a very eifective means for mounting a permanent magnet therein, wherein the punch holder is securely magnetically adhered to a supporting surface.

The novel die holder according to the present invention is also of a minimum size, and employs an arrangement including a slidable pin having a sharpened upper end portion which cooperates with the die bushing mounted in the die holder to positively prevent turning movement of the die holder during operation.

The savings in space provided according to the present invention are quite significant since not only may the punch and die holders be spaced quite close to each other, but there are no bulky dies to be stored, but only the two sheet metal templets must be stored in order to duplicate a certain set-up. It is apparent that the construction permits very simple and ready adjustment of the punch and die holders relative to the associated supporting surfaces, and the structure is very simple and inexpensive in construction, yet is quite sturdy and reliable in operation.

As this invention may be embodied in several forms Without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, and since the scope of the in- Vention is defined by the appended claims, all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are therefore intended to be embraced by those claims.

We claim:

1. In a punch and die assembly, a die shoe, a punch shoe spaced from said die shoe, a punch-holder magnetically adhered to said punch shoe and having a punch, a die holder supported by said die shoe and having a die axially aligned with and adapted to receive said punch, said punch holder and said die holder being adjustable to enable the punch and die of said holders to be axially aligned, said die holder including means for engaging a die templet and preventing the die holder from turning during operation, said means for preventing turning of the die holder comprising a pin member having a sharpened upper end portion, means resiliently urging said pin upwardly for continuously engaging an associated die template, and said die being adapted to fit snugly within an opening formed in the associated die template, whereby interaction of the pin member and die with an associated die template prevents turning of the die holder.

2. In a punch and die assembly, a die shoe, a punch shoe spaced from said die shoe, die templet support means connected with said die shoe, a die templet supported by said die templet support means, a punch holder including a permanent magnet, said punch holder being in abutting relationship with said punch shoe and magnetically adhered thereto, a die holder supported by said die shoe, a punch supported by said punch holder, a die bushing supported by said die holder in axial alignment with and adapted to receive said punch, said die templet being provided with an opening formed therethrough receiving said die bushing, said die holder including means engaging the under surface of said die templet for preventing rotation of the die holder during operation, said last-mentioned means comprising a pin having a sharp upper end portion, said pin being slidably mounted in said die holder, and means resiliently urging said pin in an upward direction, whereby interaction of the pin and die bushing with the die template prevents turning of the die holder.

3. Apparatus as defined in claim 2, including first gauge means fixedly mounted upon said die templet, and resilient spring gauge means mounted on said die templet and spaced from said solid gauge means, said resilient gauge means having a portion for engaging a workpiece, said portion being movable relative to said die template, said solid gauge means and spring gauge means cooperating to position a workpiece in the apparatus.

4. In a punch and die assembly, a die shoe, a punch shoe spaced from said die shoe, a punch holder having a substantially circular cross-section, said Punch holder including a pair of substantially annular insulatin sleeves, a substantially annular permanent magnet positioned between said insulating sleeves, said permanent magnet being disposed adjacent the upper end portion of said punch holder, said upper end portion of the punch holder being in abutting relationship with said punch shoe and magnetically retained thereon, and a die holder supported by said die shoe, said die holder including means for preventing movement of said die holder during operation, said punch holder including a central portion inwardly of said magnet and sleeves for receiving a punch, said central portion being formed of a hardened material having good impact strength to withstand the pounding of the head of a punch therein during operation.

5. Apparatus as defined in claim 4, wherein said die holder includes a die bushing axially aligned with said punch holder so as to receive a punch supported by said punch holder, said die bushing having a groove in the outer surface thereof, and a snap ring mounted in said groove for retaining said die holder in position on a die templet.

6. Apparatus as defined in claim 4, wherein said die holder has an opening formed in the upper surface thereof, a pin slidably mounted in said opening and having a sharpened upper end portion, means resiliently urging said pin in an upward direction, and means limiting upward movement of said pin, a die bushing supported by said die holder and being axially aligned with said punch holder so as to receive a punch supported by said punch holder, the sharpened upper end portion of said pin being adapted to continuously engage an associated die template, and said die bushing being adapted to fit snugly within an opening formed in an associated die template whereby interaction of the pin and die bushing with an associated die template prevents turning of the die holder.

7. In a punch and die assembly, a die shoe, a punch shoe spaced from said die shoe, means for supporting a die templet adjacent said die shoe, in magnetic punch holder including a body portion, a permanent magnet supported in said body portion, magnetic shielding means disposed adjacent said permanent magnet, said punch holder being magnetically adhered to said punch shoe, said punch holder including means for mounting a punch, a punch supported by said punch holder, a die holder supported by said die shoe, a die bushing supported by said die holder, said die bushing being axially aligned with and having an opening for receiving the punch supported by the punch holder, said die holder having an opening formed in the upper surface thereof, a pin slidably mounted in said opening, said pin having a sharpened upper end portion, means resiliently urging said pin in an upward direction, said pin being adapted to engage the undersurface of a die templet, and said die bushing being adapted to fit snugly within an opening formed in the die template whereby interaction of the pin and die bushing 10 with the die template prevents turning movement of said die holder during operation of the apparatus.

8. Apparatus as defined in claim 7, wherein said die bushing has a groove formed in the outer surface thereof, and a snap ring mounted in said groove for retaining the die holder in position relative to a die templet.

9. Apparatus as defined in claim 7, wherein said punch holder includes a collar portion adapted to be received within cooperating openings in a punch templet, and stripper means supported by the punch mounted in the punch holder.

10. In a punch and die assembly, a punch holder com prising a body portion having a central opening formed therein for receiving a punch, said body portion having a groove formed therein, an inner insulating sleeve mounted in said groove, an outer insulating sleeve mounted in said groove and spaced outwardly of said inner insulating sleeve, a permanent magnet mounted between said insulating sleeves, and a core member supported between said sleeves and adjacent said permanent magnet, said core member being disposed at the end portion of the punch holder which is adapted to engage the surface of a punch shoe, said opening being formed in a central body portion inwardly of said magnet and sleeves, said central "body portion being formed of a hardened material having good impact strength to withstand the pounding of the head of a punch therein during operation.

11. Apparatus as defined in claim 10, wherein one of said sleeves includes a turned-over end portion to retain the permanent magnet in operative position on the punch holder.

12. In a punch and die assembly, a punch holder including a body of substantially circular cross-section, said body having a central opening formed therein for receiving a punch, said body portion having a collar of reduced dimension formed at one end thereof, said body also having a groove formed in the outer surface thereof adjacent the opposite end portion of the body, an inner substantially annular magnetic insulating sleeve mounted in said groove, a substantially annular permanent magnet mounted in said groove in surrounding relationship to said inner sleeve, an outer magnetic insulating sleeve disposed in surrounding relationship to said permanent magnet, a substantially annular core member supported between said sleeves adjacent said opposite end portion of the body, the outer end portion of said inner sleeve being turned over and engaging said core for retaining the core and permanent magnet in operative position relative to said body, said opening being formed in a central body portion inwardly of said magnet and sleeves, said central body portion being formed of a hardened material having good impact strength to Withstand the pounding of the head of a punch therein during operation.

13. In a punch and die assembly, a die holder comprising a body means having an opening formed in the upper surface thereof for receiving a die bushing, said body also having a passage formed therein in communication with said opening for directing slugs out of said body, an opening formed in the upper surface of said body, a pin slidably mounted in said opening, said pin having a sharpened upper edge portion, means resiliently urging said pin in an upward direction, said pin having an enlarged head formed thereon, and means for engaging said head for limiting upward movement of said pin, a die bushing mounted in said first-mentioned opening of the die holder, the sharpened upper edge portion of said pin being adapted to engage an associated die template and said die bushing being adapted to fit snugly within an opening formed in the associated die template whereby interaction of the pin and die bushing with the associated die template prevents turning of the die holder during operation.

14. Apparatus as defined in claim 13, wherein said die 11 bushing is provided with a circumferentially extending groove formed in the outer surface thereof for receiving a snap ring to retain the die bushing and die holder in place on an associated die template.

References Cited in the file of this patent UNITED STATES PATENTS 375,354 Hodgson Dec. 27, 1887 942,146 Robinson Dec. 7, 1909 1,279,362 Krueger Sept. 17, 1918 2,064,401 Stellin Dec. 5, 1944 2,364,834 Whistler Dec. 12, 1944 12 .ioachimi Apr. 17, 1945 Bechtel June 26, 1945 Jackson Oct. 16, 1945 Kopczynski Nov. 25, 1947 Stevens Oct. 26, 1948 Hermann Sept. 18, 1951 Kopczynski Dec. 23, 1952 Coleman Apr. 14, 1953 Kopczynski Aug. 12, 1958 Wursch May 5, 1959 FOREEGN PATENTS Great Britain May 15, 1903

Claims

1. IN A PUNCH AND DIE ASSEMBLY, A DIE SHOE, A PUNCH SHOE SPACED FROM SAID DIE SHOE, A PUNCH-HOLDER MAGNETCALLY ADHERED TO SAID PUNCH SHOE AND HAVING A PUNCH, A DIE HOLDER SUPPORTED BY SAID DIE SHOE AND HAVING A DIE AXIALLY ALIGNED WITH AND ADAPTED TO RECEIVE SAID PUNCH, SAID PUNCH HOLDER AND SAID DIE HOLDER BEING ADJUSTABLE TO ENABLE THE PUNCH AND DIE OF SAID HOLDERS TO BE AXIALLY ALIGNED, SAID DIE HOLDER INCLUDING MEANS FOR ENGAGING A DIE TEMPLET AND PREVENTING THE DIE HOLDER FROM TURNING DURING OPERATION, SAID MEANS FOR PREVENTING TURNING OF THE DIE HOLDER COMPRISING A PIN MEMBER HAVING A SHARPENED UPPER END PORTION, MEANS RESILIENTLY URGING SAID PIN UPWARDLY FOR CONTINUOUSLY ENGAGING AN ASSOCIATED DIE TEMPLATE AND SAID DIE BEING ADAPTED TO FIT SNUGLY WITHIN AN OPENING FORMED IN THE ASSOCIATED DIE TEMPLATE WHEREBY INTERACTION OF THE PIN MEMBER AND DIE WITH AN ASSOCIATED DIE TEMPLATE PREVENTS TURNING OF THE DIE HOLDER.