Patent GB-282248-A (GB)
Title: Improvements in and relating to feeding devices for the paper carriage in typewriters
IPC: B41J19/66
Filed: 1927-03-21
Abstract: 282,248. Triumph-Werke N³rnberg Akt.-Ges., and Kupfer, C. March 21, 1927. Letter - spacing mechanism; carriagereleasing arrangements; carriage brakes. - Relates to escapement mechanism having automatic means for releasing the coupling or clutch between the escapement wheel and feed-pinion to permit silent return of the carriage, and comprises (1) a pawl-and-ratchet coupling having the pawls in engagement with pins on a disc which is displaced automatically by means of a friction disc on return o f the carriage or can be displaced by the carriage-releasing devices, (2) a similar coupling wherein the friction-disc is replaced by brake-levers, and the carriage-releasing devices are arranged to release the brakelevers, and (3) a clutch comprising a member which is displaced axially on return of the carriage. In the mechanism shown in Figs. 2 and 3, a shaft 5 carries a fast feed-pinion 4, a fast ratchet-wheel 3, and a loose escapement-wheel 1 provided with pawls 2 co-operating with the ratchet-wheel and having slots engaging pins 8 on a toothed disc 7 loose on the hub of the ratchetwheel. A disc 9 loose on the hub of the disc 7 has arms 15, the upper arm being connected to a spring 16 and the lower arm abutting on a stop 17 and being provided with a pawl 18 connected to a rod 19. The disc 9 frictionally engages the disc 7 and abuts on a loose disc 10, a spring 14 being arranged between the feed-pinion and disc 10. During letter-spacing the pawls 2 couple the escapement wheel to the feed-pinion, but when the carriage is returned the disc 7 turns slightly and the pins 8 release the pawls and thereby permit silent return of the carriage. For carriagerelease the rod 19 is raised thereby causing the pawl 18 to rotate the disc 7 slightly and release the pawls 2. On release of the rod, the disc 9 returns to normal position, the disc 7 is returned frictionally, restoring engagement of the pawls 2, and the pawl 18 is released by the rod. In the mechanism shown in Figs. 5 and 8, the escapement wheel 22, fast on a,shaft 21, carries pawls 23 engaging a ratchet-wheel 31 secured to the hub of a loose feed-pinion 30, a disc 28 loose on the hub having pins 27 engaging slots in the pawls. A ratchet-wheel 32 loose on the hub of the disc 28 is coupled thereto by means of pins and slots 36, 37. Brake-levers 41, 42 connected by a pivot 40 and drawn together by a spring 44 engage flats in the hub of the disc 28, and engage also a neck on the hub of the feed-pinion 30. The ratchet-wheel 32 has a pin 48 arranged between curved arms 45, 46 on the brake-levers. When the carriage is returned, the disc 28 is rotated slightly by the brake-levers and the pawls 23 are released from the ratchet-wheel 31. The carriage-releasing devices are arranged to rotate slightly the ratchet-wheel 32 and thereby cause the disc 28 to release the pawls 23, the pin 48 simultaneously engaging the arms 45, 46 and forcing apart the brake-levers, thereby relieving the feed-pinion from the action of the brakelevers during the movement of the carriage. On return of the carriage-releasing devices, a spring 49 restores the disc and related members to normal position. In the mechanism shown in Fig. 16, the escapement wheel 54 is secured to a clutch-member 53 which is fast on a shaft 52 carrying a loose feed-pinion 56 having a hub 57 carrying a loose clutch-member 60. A spring 59 arranged between a cap 58 and a flange 61 normally holds the clutch-members in contact. The clutch-member 60 has a pin 63 engaging one angle of a triangular recess in the hub 57. When the carriage is returned the inclined face of the recess slides over the pin and thereby separates the clutch-member 60 from the clutch-member 53, permitting silent return of the carriage. A blade 67 attached to the clutch-member 53 is formed with a curved brake-spring which engages the clutch-member 60 and prevents free movernent when the carriage is returned.