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Print Hammer Position Sensor

IP.com Disclosure Number: IPCOM000085677D
Original Publication Date: 1976-May-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Freeman, WD: AUTHOR [+2]

Abstract

A print hammer position sensing mechanism insures the proper return of a print hammer from its printing position prior to initiating print element motion, thereby eliminating possible print element damage and increasing system printing efficiency.

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Print Hammer Position Sensor

A print hammer position sensing mechanism insures the proper return of a print hammer from its printing position prior to initiating print element motion, thereby eliminating possible print element damage and increasing system printing efficiency.

A printer includes a rotating spoke print wheel 11 having type characters 13 positioned about the periphery thereof. Print hammer unit 15 is actuated causing the print hammer 17 to strike the spoke carrying a print character 13 and drive it against platen 19.

A rigid sensing flag 21 is mounted on the hammer 17 and moves therewith. A phototransistor-light emitting diode unit 23 senses the position of sensing flag 21 as it moves therepast. The unit 23 is adjustable so that an output signal is obtained when the hammer mass passes a specified point. The output signal is in turn utilized to prevent further print wheel motion when the hammer 17 is not at rest position. The output signal is also utilized to indicate when print wheel 11 can be rotated to a different character position.

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