| 摘要 |
830,526. Typewriters &c. INTERNATIONAL COMPUTERS & TABULATORS Ltd. April 14, 1958 [May 6, 1957], No. 14406/57. Class 100(4) A paper feeding device comprises pin wheels 21 or other feeding means driven by an output shaft 6 from a continuously rotating drive shaft 2 through a friction clutch and provided with selectively operable stop means declutch the drive in two or more positions and means to retain the output shaft against rotation in one direction and locating means preventing rotation in the other direction. The friction clutch comprises bushes 5, 7 within a drum 10 normally rotating together by the action of a spring 8 around the bushes. The drive is stopped by the engagement of a selected lug 12 by a stop member 13 unlatched by an electromagnet 29, which holds the drum 10 and allows the spring 8 to unwind sufficiently to unclutch the bushes 5, 7. Forward rotation of the shaft 6 is prevented by engagement of a projection 14 of the drum 10 with a slot 15 in the bush 7 while backward rotation is prevented by locating means comprising a pawl 17 engaging a ratchet wheel 16. When the drum 10 is stopped the drive continues under the force of the spring 8 sufficiently to allow engagement of a pawl 17 to accurately position the paper. The feed is restarted by energizing an electromagnet 28 which withdraws the stop member 13 and allows it to be re-latched. The central part of the shaft 6 is reduced to form a torsion rod and is enclosed in a tube 31 which normally provides a rigid drive by lug 38 of a sleeve member 32 engaging one side of slots 39 of a driving collar 40 of the shaft 6. A sudden stopping of the paper feed causes the torsion rod part to twist while the inertia of the paper feed is absorbed, when the bush 7 is stopped, by continued rotation of the right hand end of the shaft 6 twisting it and turning the tube 31 against the frictional engagement of its collar 32 with a conical part 35 under the force of a spring 36 while the lugs 38 move in the. slot 39 made wide enough to allow this.
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