Browse Prior Art Database

Rotary Backspace Mechanism

IP.com Disclosure Number: IPCOM000093625D
Original Publication Date: 1967-Nov-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Everhard, PR: AUTHOR [+3]

Abstract

Typewriter letter feeding carrier 1 is stepped in backspace direction B by motion applied from ratchet wheel 4 through cord 2 and capstan 3. Ratchet wheel 4 is driven counterclockwise by pawl 5 upon rotation of cam 6. The effective stroke of pawl 5 is controlled by adjustable datum cam 7. The latter acts against post 8 on pawl 5 to select greater or lesser lost motion prior to engagement between pawl 5 and ratchet 4. Sam 7 is remotely positioned by shielded cable S. Frictional interference with proper backspace operation is minimized by attaching cord 2 to carrier 1 closely adjacent to support rod 9 along which carrier 1 slides. Spring 10 biases capstan 3 counterclockwise to maintain tension in cord 2 such that lost motion between ratchet 4 and carrier 1 is minimized.

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Rotary Backspace Mechanism

Typewriter letter feeding carrier 1 is stepped in backspace direction B by motion applied from ratchet wheel 4 through cord 2 and capstan 3. Ratchet wheel 4 is driven counterclockwise by pawl 5 upon rotation of cam 6. The effective stroke of pawl 5 is controlled by adjustable datum cam 7. The latter acts against post 8 on pawl 5 to select greater or lesser lost motion prior to engagement between pawl 5 and ratchet 4. Sam 7 is remotely positioned by shielded cable S. Frictional interference with proper backspace operation is minimized by attaching cord 2 to carrier 1 closely adjacent to support rod 9 along which carrier 1 slides. Spring 10 biases capstan 3 counterclockwise to maintain tension in cord 2 such that lost motion between ratchet 4 and carrier 1 is minimized.

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