Browse Prior Art Database

Indexing Mechanism for Typewriters

IP.com Disclosure Number: IPCOM000093232D
Original Publication Date: 1967-Jul-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Akers, AL: AUTHOR [+4]

Abstract

This indexing mechanism can be utilized with a front feed typewriter. Easy insertion and alignment of the front fed document are realized.

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Indexing Mechanism for Typewriters

This indexing mechanism can be utilized with a front feed typewriter. Easy insertion and alignment of the front fed document are realized.

An indexing operation is initiated when rotary index drive solenoid 1 is pulsed. This causes link 2 to rotate and push down on slider crank 3 which, in turn, pulls down on connecting link 4 and pawl carrier lever 5. Downward movement of lever 5 drops pawls 6 onto drive wheel 7 from their rest position on upstops 8. Pawls 6 are locked onto drive wheel 7 by an initial spring load, then held there through the rest of the operation by a wedging action derived from the attack angle of pawls 6. Continued movement of lever 5 causes pawls 6 to impart rotational motion to drive wheel 7.

Motion of drive wheel 7 is transmitted to the document through gear train and universal shaft 10 and document feed roll 11. Pressure pads 12 are used to hold the document against the feed roll.

Adjustable downstop 13 limits the movement of pawls 6 to enable drive wheel 7 to be rotated through the correct amount of rotation. Overthrow linkage 14 allows solenoid 1 to complete its stroke.

A return spring in solenoid 1 returns the linkages and pawls 6 to their original rest positions. The attack angle on pawls 6 allows them to cam away from drive wheel 7 and slide over it on the return stroke thus preventing back drive of the document. Slider crank 3 provides low initial and end of stroke acceleration, with maximum documen...