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Backspace Printing Interlock

IP.com Disclosure Number: IPCOM000093991D
Original Publication Date: 1966-Apr-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Van Avery, CN: AUTHOR

Abstract

In a typewriter, interlocks are provided to prevent printing during a number of backspace operations. Also, initiation of a backspace operation during printing in a business machine is prevented. When a character keylever is depressed, cycle clutch trip lever 10 is permitted to rotate counterclockwise under the action of spring 11. A pulling force is applied to link 12 which trips the cycle clutch and causes printing of the selected character.

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Backspace Printing Interlock

In a typewriter, interlocks are provided to prevent printing during a number of backspace operations. Also, initiation of a backspace operation during printing in a business machine is prevented. When a character keylever is depressed, cycle clutch trip lever 10 is permitted to rotate counterclockwise under the action of spring 11. A pulling force is applied to link 12 which trips the cycle clutch and causes printing of the selected character.

The rotary movement of lever 10 permits counterclockwise movement of crank 13. Crankshaft 14 and backspace latch 15 are moved clockwise under the action of spring 16 to place latch 15 in a position where backspace actuating plate 17 cannot be moved. Under this condition, backspace keylevers 18 and 19 cannot be depressed to initiate backspace operations. At the end of a printing operation, link 12 is restored to the rear and the apparatus returns to its initial condition with latch 15 retracted from plate 17.

When keylever 19 is depressed, latch carrier 21 pivots down to pivot plate 17 and rotate shaft 22 clockwise. Printing latch 23, mounted on shaft 22, moves in front of lever 10. Even though a character keylever is depressed at this time, the cycle clutch cannot be tripped and no printing operation occurs.

As keylever 19 is further depressed, a latch 25 is moved below plate 26. Backspace interposer 27 is released to the rear to initiate a backspace operation. Also, carrier 21 is retained in it...