Patent GB-391855-A (GB)
Title: Improvements in or relating to telegraph printing and like selective apparatus
IPC: H04L17/22
Filed: 1931-11-06
Abstract: 391,855. Printing - telegraphs. CREED & CO., Ltd., Telegraph House, Croydon. - (Teletype Corporation ; 1400, Wrightwood Avenue, Chicago, U.S.A.) Nov. 6, 1931, No. 30764. [Class 100 (iv).] Case and platen shift mechanisms.-In telegraphic-receiving and like apparatus controlled by permutation selectors, the types or selectible elements are arranged in three or more cases or groups, and selection of a case or group is effected by shift means having three or more conditions, and arranged to change from any one condition to any other under control of a corresponding setting of the permutation selectors. Fig. 1 shows part of the apparatus described in Specification 245,149, [Class 100 (iv), Typewriters &c.], and comprising (1) type-levers 10 geared to actuating-bars 14 which are selected by means of permutation bars 20 and are actuated by a striker-bar 18, Fig. 8, carried by a plunger 19, and (2) a laterally shiftable frame 29 carrying a platen 30, feedroller 31, and tape-guide 28. The type-levers are now provided with three types, and the platen is shiftable into any of three positions. The shift mechanism comprises a bell-crank 45 co-operating, with an adjustable lug 47 on the frame 29, and having'a roller 49 co-operating with an eccentric 50 on a sleeve 54 which is frictionally coupled to a continuously rotating shaft 51. Stop discs 55, 56, 57 on the sleeve 54 have lugs 65, Figs. 4, 5 and 6, co-operating with hooked stop-dogs 62 which are mounted on a shaft 63 and have extensions 68 engaging fingers 69 on actuating-bars 70 controlled by the permutation bars. One stop-dog at a time co-operates with the associated stop-disc to hold the sleeve and thereby determine the position of the platen. An interlock consisting of a lever 73 and two shorter levers cooperating with the extensions 68 releases the operative stop-dog when either of the other stop-dogs is moved into operative position. When any of the three shift-signals is received, one of the actuating-bars 70 renders operative the corresponding stop-dog, the previously operative stop-dog is released, the sleeve turns until it is arrested by the operative stop-dog, and the platen is shifted by the eccentric into the position corresponding to the shift-signal, the outer, intermediate, and inner positions being determined by the stop-discs 55, 56, 57 respectively. The more frequently used types are arranged in the intermediate group, the stop-disc 56 having two lugs 65 so that shift from the outer or inner position can be effected by a quarter-revolution of the eccentric. Letter-spacing mechanism.-A ratchet-wheel 39, Fig. 8, on a shaft 38 geared to platen shaft 33 co-operates with a letter-spacing pawl 40 carried by a lever 41 which is operated by a cam-seat 42 in the plunger 19. During operation of the shift mechanism, the letter-spacing mechanism is silenced by engagement of a latch 79 with the lever 41. The latch engages a finger 78 on a bail 76 having a finger 75 resting on extensions 74 of the bars 70, movement of any of these bars permitting the latch to engage the lever.