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Microfeed Mechanism for Typebar Typewriter

IP.com Disclosure Number: IPCOM000093522D
Original Publication Date: 1967-Oct-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Brown, LC: AUTHOR

Abstract

Web 1 is fed by rolls 2 at either of two fundamentally different rates. Such are selected by control member 3 from motion provided by an oscillating input 4 that moves through a substantially constant arc. Spring clutch 5, connected between shaft 6 and stroke arm 7, is oscillated through an arc. The latter is defined by lost motion controlling slot 8 which is adjustably attached to oscillating input bracket 9. Control 3 in the fast mode acts through bail 10 to hold braking pawl 11 out of braking tooth 12 and to hold alternate feed pawl 13 out of ratchet 14. In this mode, all clockwise motion transmitted from oscillating bracket 9 to feed arm 7 is transmitted via clutch 5 to rolls 2.

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Microfeed Mechanism for Typebar Typewriter

Web 1 is fed by rolls 2 at either of two fundamentally different rates. Such are selected by control member 3 from motion provided by an oscillating input 4 that moves through a substantially constant arc. Spring clutch 5, connected between shaft 6 and stroke arm 7, is oscillated through an arc. The latter is defined by lost motion controlling slot 8 which is adjustably attached to oscillating input bracket 9. Control 3 in the fast mode acts through bail 10 to hold braking pawl 11 out of braking tooth 12 and to hold alternate feed pawl 13 out of ratchet
14. In this mode, all clockwise motion transmitted from oscillating bracket 9 to feed arm 7 is transmitted via clutch 5 to rolls 2.

When control 3 is moved downwardly to the slow position, pawl 11 is allowed to move toward tooth 12 and pawl 13 is allowed to engage ratchet 14. Clockwise oscillation of bracket 9 allows pawl 11 to fall under tooth 12 and lock arm 7 in its clockwise extreme moved position. Arm 7 is thus prevented from following bracket 9 on subsequent strokes.

In this mode, clockwise oscillation of bracket 9 drives pawl 13 into ratchet 14 to increment feed motion reducing cam 15 a part revolution. Cam 15 acts on follower 16 to lift pawl 17 which engages ratchet 18 attached to shaft 6. Ratchet 18 is thus incremented a small angular amount proportional to the rise of cam 15 for each revolution of ratchet 14 and shaft 6 is fed clockwise an equally small amount....