US3478629A - Hole punching devices for recording media - Google Patents

Description

Nov. 18, 1969 EK ETAL 3,478,629

HOLE PUNCHING DEVICES FOR RECORDING MEDIA Filed May 1, 1967 2 Sheets-Sheet 1 4 M/I/F/VTOES mean Hi/Vf/K 5K Jwm gum/5e WA/rie :rzwwp Nov. 18, 1969 B. H. EK EFAL HOLE PUNCHING DEVICES FOR RECORDING MEDIA .2 Sheets-Sheet 3 Filed May 1, 1967 United States Patent 9 Claims ABSTRACT OF THE DISCLOSURE This invention relates to hole punching devices for punch tapes and similar recording media and has for an object the provision of a punch head in which a plurality of punches 21 are combined in a rigid yet easily interchangeable way with a punch die 17 and punch guide means 14. The punch guide means are formed as a bar having a cylindrical shank portion 12 fitted into a base member and adjustable angularly and longitudinally therein. The punches 21 are mounted for longitudinal displacement within transversal holes drilled in said punch guide 14 employing the overhanging rod-shaped punch die 17 mounted in said punch head 12, 14 as a drill jig. The upper ends of the punches 21 are connected to bell cranks 27 actuated by push rods 29 from a drive mechanism known in itself, and this connection is established and disestablished by turning the punch head shank 12 relative to the base member 10.

This invention relates to hole punching devices and the like apparatus for punch cards, punch tapes and similar recording media.

In known hole punching apparatus for punch tapes the "ice work is made when manufacturing the punch head which is delivered as an exchangeable unit which can be mounted by servicing personnel without any special equipment or training.

The improved punch head comprises a punch die, a plurality of punches for engaging punch holes in the die and punch guides, and according to the invention the punch guides and punch die are rigidly combined to an exchangeable unit provided with a cylindrical shank member which is supported by a base member and is angularly as well as longitudinally adjustable therein.

The invention will be described more in detail with reference to the annexed drawings, wherein FIG. 1 is a fragmentary elevation view of a punch head as seen from the side wherefrom the tape is inserted,

FIG. 2 is a somewhat diagrammatical cross section view along A--A in FIG. 1,

FIG. 3 is a top plan view of a punch die, and

FIGS. 4 and 5 is an elevation view and end view, respectively, of a second embodiment of the principal parts of a punch head.

In FIG. 1 numeral 10 denotes a base member which is preferably shaped as a thick plate. This plate 10 has punching mechanism is supported by a rigid base memher, most often made of cast iron. The punch die which must be made of a wear-resistant material, usually hardened steel, forms as a rule a separate unit that is mounted on the base member. The same applies to the punch guides which must be machined to close tolerances to prevent the punches from striking against the hole walls of the die. The fitting of the punch guides and the punch die in the base is therefore an expensive operation. Since the punches, the punch guides and the die belong to those components subjected to the heaviest wear it is desirable that they can be exchanged swiftly and without much fitting. This is not possible in most punching devices commercially available at present.

It has been proposed to improve the interchangeability of components subjected to wear by forming the die and the punch guides in separate components provided with guide =bores which fit accurately around two closely ma chined guide columns. Distance pieces are also mounted at those columns, to provide a channel for the tape.

To attain complete interchangeability the said components must be machined to very close tolerances, and the replacement of parts is a comparatively tedious operation, as a great number of components shall be changed and assembled in a certain order. Another limitation imposed by this construction is that the tape must be inserted through the punch head which complicates handling. Moreover, the punching device cannot be used for punching the edges of cards, as this requires the punching area to be accessible laterally.

The present invention has for its object the provision of a punch head without these drawbacks. This punch head is easily exchangeable by loosening a single screw, and the punch die as well as the punches and punch guides are removed in a single operation. All precision a cylindrical bore 11 therein receiving a shank portion 12 of a punch head unit 14 which is angularly and longitudinally adjustable within the said bore. The punch head shank 12 is secured axially and radially by a set screw 13. The punch head 14 extends beyond the base member 10 and has its cross section shaped like a segment of a circle and acts as a punch guide. The punch head is preferably made of a material suited for guiding the punches which are made of steel or the like, such as brass or auto-lubricating bronze. If the punch head 14 is not made of a self-lubricating material it is preferably formed with an axial bore 15 which is filled with a lubricant.

Parallel to the flat underside 16 of the punch head 14 a cylindrical punch die 17 is rigidly mounted in a bore 18 in the cylindrical shank 12. The spacing between the highest portion of the die 17 and the flat bottom surface 16 0f the punch head is determined by the thickness of the medium to be punched. Before the die is rigidly secured in the bore 18 punch holes 19 are drilled therein, corresponding in FIG. 3 to an 8-channel punch tape. The holes are drilled with clearance downwards to prevent the punched-out matter to stick. If the die shall be hardened this is also effected before its mounting in the punch head, of course.

The punch die now is used as a drill jig for drilling the guide holes 20 in the punch head, to ensure that the latter will become accurately aligned with those in the die. The fitting of the die 17 in the bore 18 need not be made with any too great accuracy, as a minor deviation of the die holes from 'being perpendicular to the surface 16 is of no importance. 'By turning the punch head relative to the bore 11 any possible oblique position of the punches rela-' tive to the punch drive mechanism will be readily compensated.

After the bores in the die and punch head have been machined to their final measure and smoothness the punches 21 are mounted in the holes 20 and the punch head can be inserted by its shank 12 in the bore 11 in plate 10. During this operation the punch head is turned in such a way that the punches coincide for example with the plane indicated at 22 in FIG. 1. When in the correct axial position the punch head is turned clockwise until a milled-down portion 23 near the top of each punch engages a slot 24 in a bell crank 27 transmitting the drive to the punch. The top portion of the latter is received in a transverse slot in the bell crank 27. All bell cranks are supported by a common axle 28 and are actuated by push rods 29 engaging recesses 29a in the bell cranks. The push rods 29 are actuated individually in any known or suitable manner, for example by electromagnets (not illustrated). When a push rod 29 is moved to the left in FIG. 1, its associated bell crank 27 urges the punch 21 downwards, and a hole is punched in the recording medium. On return of the bell crank the punch is pulled back into initial position. To prevent the overhangingdie 17 from giving way during punching two supporting pads 30, 31 are provided. These pads are shaped with oblique sides 32 defining a chute for the punched-out matter. The pads 30, 31 are secured to the base member 10.by means of screws 33, and a plate 34 is mounted 'as a cover at their outer face.

Since one end of the dies 17 is free a punch tape can be inserted laterally into the space 35 between the punch head and the die. This is eifected much faster than threading the tape through a gap closed at both sides.

Exchange of separate punches as well as of the complete punch head is easily effected in the embodiment illustrated. By loosening the set screw 13 the whole unit can be turned within the bore 11 to release the punches from their? engagement with the bell cranks 27. Any of the punches may be extracted from the punch head to be replaced by a new one. If the pads 30, 31 are removed the complete punch head may be exchanged by a simple operation.

A worn punch head may simply be scrapped, as it is much less expensive to manufacture than earlier known punch heads of a comparable quality.

It is possible to recondition a worn punching device by machining the bores in the punch guide and die to a slightly greater diameter. The punches are then replaced by new ones having a greater diameter. The reconditioning can be effected without further dismounting and is therefore very inexpensive.

In the modified embodiment illustrated in FIGS. 4 and 5 the punch head is made of a steel cylinder 35 with an axial, eccentrically offset bore 36. The cylinder 35 further has an axial slit 38 for guiding the recording tape through the punch head. The slit partly intersects the bore 36. The distance between the bottom 39 of the slit and the circumference of the bore 36 corresponds to the thickness of the medium to be punched. The portion 40 of the cylinder disposed below the slit provides the punch die and has holes 19 machined therein like the die illustrated in FIG. 3. Also the wall of the cylinder 35 above the bore 36 is formed with corresponding holes with a greater diameter than those of the die. After the cylinder has been hardened, a hollow bush 37 of bronze or similar material is forced into the bore 36, and holes are drilled through the walls of the bush 37, using the die as a drill jig. After machining the drilled holes to final measures and smoothness the punches are mounted in the holes. The bush 37 acts as a punch guide, and its hollow interior is preferably filled with a lubricant. The bush may be made of a self-lubricating bronze or the like, instead, which makes special oil channels unnecessary.

This punch head is mounted in the same way as the first one described above, by inserting the cylindrical shank portion41 into the bore in the base member 11.

What we claim is:

1. A hole punching device for punch tapes, punch cards and the like recording media, comprising a punch die, a plurality -of punches and guide means for the punches, wherein the said punch guide means, the punches and the punch die are combined in an exchangeable punch head which is provided with a cylindrical shank portion mounted with angular and longitudinal adjustability in a base member.

2. A hole punching device as claimed in claim 1, wherein the punch head is shaped as a straight circular cylinder having a recess extending parallel to the cylinder axis at least in the part thereof beyond the shank portion.

3. A hole punching device as claimed in claim 2, wherein the said recess includes a cylindrical segment,

. said punch die comprising an elongated, substantially cylindrical portion disposed within said recess parallel to the cylinder axis.

4. A hole punching device as claimed in claim 3, wherein said cylindrical segment is formed of bronze, said die being formed with holes for receiving said punches.

5. A hole punching device as claimed in claim 4, wherein said punch guide is formed with an axial bore containing a lubricant.

6. A hole punching device as claimed in claim 2, wherein said cylinder is made of a material suitable for a punch die, such as steel, and wherein said recess is formed as a bore parallel to the cylinder axis, an axial slit having one limiting surface intersecting the circumference of the bore is machined from the free end of the cylinder to a depth corresponding to the width of the recording medium support, the height of the slit being greater than the thickness of the said recording medium support, and a bush of a material suited as a guide for the punches is inserted into said bore.

7. A hole punching device as claimed in claim 6, wherein holes for the punches are drilled diametrically through the cylinder and the bush perpendicularly to said slit.

8. A hole punching device as claimed in claim 7, wherein said bush is provided with a channel for the lubricant traversed by the punches.

9. A hole punching device as claimed in claim 8, wherein portions of the punches are disconnected from said drive means upon angular displacement of the punch head.

References Cited UNITED STATES PATENTS 2,325,437 8/1943 Temple 83622 X WILLIAM S. LAWSON, Primary Examiner U.S. Cl. X.R.

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