Browse Prior Art Database

Typewriter Case Shift Device

IP.com Disclosure Number: IPCOM000097076D
Original Publication Date: 1962-May-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Kleinbeck, E: AUTHOR

Abstract

The device eliminates the necessity of holding the shift key depressed until the type impact has occurred. After the shift key is released, the case shift is maintained by a lock pawl mechanism. It is released again by the next, following depression of a character key. The case shift lock may also be disengaged arbitrarily.

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Typewriter Case Shift Device

The device eliminates the necessity of holding the shift key depressed until the type impact has occurred. After the shift key is released, the case shift is maintained by a lock pawl mechanism. It is released again by the next, following depression of a character key. The case shift lock may also be disengaged arbitrarily.

Key lever 1 of shift key 2 has mounted on it pivot pin 3 which supports shift lock pawl 4. When shift lock key 5 is actuated, pawl 4 is rocked and with its shoulder 6 engaged behind latch bar 7. On depression of shift key 2, it is restored by spring 8. This is attached to arm 9 of key lever 1. Connecting rod 10 leads to the shift key on the other side of the keyboard.

Pivot pin 3 has mounted on it lock pawl 12 separated from pawl 4 by washer
11. Pawl 12 is loaded by draw spring 14 and, when shift key 2 is depressed, shoulder 13 is engaged behind latch bar 7. On the next following depression of a character key, the lock pawl is restored by guide 15 actuated by the ribbon bail (not shown).

Lock pawl 12 carries spring-loaded detent 19 which normally has its shoulder 20 positioned above latch bar 7. When lock pawl 12 moves downwardly, detent 19 is rocked against the force of its spring. When the lock pawl is restored, detent 19 is released and has its shoulder 20 resting against the latch bar. Thus, if shift key 2 is held depressed beyond the time lock pawl 12 is restored by guide 15, detent 19 prevents lock pawl 12 fr...