Browse Prior Art Database

Card Punch Configuration

IP.com Disclosure Number: IPCOM000091759D
Original Publication Date: 1968-May-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Eide, SL: AUTHOR [+2]

Abstract

This tip configuration for a card punch facilitates expulsion of chads from a punched, prescored tabulating card. Punch 1 cooperates with hole 2 in die 3 to remove prescored chad 4 from record card 5. Hole 2 is of larger diameter than the cross-section of punch 1. Hole 2 is countersunk at 6 to provide at its maximum dimension an opening comparable to that of the cross-section of chad 4.

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Card Punch Configuration

This tip configuration for a card punch facilitates expulsion of chads from a punched, prescored tabulating card. Punch 1 cooperates with hole 2 in die 3 to remove prescored chad 4 from record card 5. Hole 2 is of larger diameter than the cross-section of punch 1. Hole 2 is countersunk at 6 to provide at its maximum dimension an opening comparable to that of the cross-section of chad
4.

The sharp circumferential edge 7 and tip 8 formed during machining of punch 1 are intentionally left intact without deburring.

The sharp corner and tip 8 provide a restrictive friction contact surface for chad 4 as it is driven into the countersink. This contact helps to cause chad 4 to wrap itself around the end of punch 1 and be guided by the countersink. Thus, equal pressure is applied to burst all the unscored portions holding chad 4 to card 5.

Punch 1 is maintained coaxially aligned with countersunk die hole 2. To assure this critical alignment, die template 9 of adequate thickness is used, irrespective of whether punch 1 is hand or mechanically operated. Thus, as punch 1 moves downward, tip 8 successively contacts chad 4 and then drives chad 4 downward into the countersink. Chad 4 is thus caused to wrap around the lower end of punch 1 as it is evenly driven through hole 2. Chad 4 drops free of die 3, facilitating retraction of punch 1 to its starting position.

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