Browse Prior Art Database

Selective Nonescape Mechanism

IP.com Disclosure Number: IPCOM000078038D
Original Publication Date: 1972-Jul-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Haus, RA: AUTHOR

Abstract

In a typewriter like that shown in U. S. Patent 2,919,002, characters can be printed without an accompanying letter space through the use of nonescape actuator 10 and latch spring 11, which cooperate to effectively sever the drive connection from escapement drive link 13 to escapement pawl 14. Type element carrier 15 contains escapement drive cam 16 which normally rocks bell crank 17, to reciprocate drive arm 13 and thereby lift escapement pawl 14 from stationary rack 18 extending along the typewriter writing line. The type element carrier 15 thus is advanced one letter space by the usual main spring bias, not shown. Printing of certain characters, such as accents and underscores, is efficiently done by eliminating the usual forward space accompanying the print operation.

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Selective Nonescape Mechanism

In a typewriter like that shown in U. S. Patent 2,919,002, characters can be printed without an accompanying letter space through the use of nonescape actuator 10 and latch spring 11, which cooperate to effectively sever the drive connection from escapement drive link 13 to escapement pawl 14. Type element carrier 15 contains escapement drive cam 16 which normally rocks bell crank 17, to reciprocate drive arm 13 and thereby lift escapement pawl 14 from stationary rack 18 extending along the typewriter writing line. The type element carrier 15 thus is advanced one letter space by the usual main spring bias, not shown. Printing of certain characters, such as accents and underscores, is efficiently done by eliminating the usual forward space accompanying the print operation. In the mechanism shown, selection of such characters causes an air pulse to be supplied to actuator 10 early in the print cycle. Actuator 10 lifts drive arm 13 to a position where tab 19 clears the wire spring 11, permitting the wire spring to move leftwardly and trap the drive arm 13 in its raised position. In this position, drive arm 13 misses the escapement pawl 14 during its reciprocation and no letter feed is accomplished. During reciprocation of drive arm 13, however, the tab 19 moves leftwardly beyond the motion available to wire spring 11 due to spring stop 20, and thus the drive arm 13 is permitted to return to its original effective position under the infl...