Patent GB-549420-A (GB)
Title: Improvements in or relating to means for preparing facsimile messages for transmission
IPC: H04L17/24
Filed: 1941-04-18
Abstract: 549,420. Typewriters. CREED & CO., Ltd., THOMPSON, A. E., and SALMON, R. D. April 18, 1941. No. 5048. [Class 100 (iv)] [Also in Group XL] A unitary facsimile telegraph machine comprises a transmitter, a receiver and a typewriter for the preparation of the message. The unitary apparatus shown in Fig. 1 consists of a receiver 23, 24, 25 for printing the received message on a tape T, typing- mechanism (controlled by a single handle 26 and including a type-wheel 12 and hammer 13) for typing the received message on the tape, and as canning- system consisting of a lamp 16, lenses 17, 18, and a photo-electric cell 19. The typing mechanism includes the features described below. Index type-wheel machines; hammer-impression arrangements. The handle 26, Fig. 2, is pivoted on a carriage 28 in connection with an endless band passing over two pulleys, one of these being geared to the shaft of the type-wheel. When the handle is moved laterally to a position determined by a pointer 30 on the carriage and an index-drum 31, the type-wheel 12 is turned to present the corresponding type to the hammer. On depression of the handle,lug thereon engages an aligning-comb 32, and the hammer 13 is operated. The hammer-shaft is coupled by a spring 41to a lever 39 abutting on a bell-crank 38 carried by another bell-crank 36 which is coupled by a link 35 to a bail 33 abutting on the handle. On depression of the handle, the bell-crank 36 causes the bell-crank 38 and lever 39 to retract the hammer, and when the bellcrank 38 engages a stop 42, the lever 39 is released, a tensioned spring 40 fires the hammer. The tape T is arranged between the typewheel and an ink ribbon 14 which passes around the hammer. Case-shift mechanism. The type-wheel is shifted or unshifted by depressing the handle 26 after it has been been moved into extreme left-hand position. Depression of the handle rocks a sector 62, Fig. 4, and thereby causes a pawl 64 to ride over a ratchet-wheel 65 on the index-drum 31. On release of the handle, the sector is returned by a spring.66 the index-drum is turned through a right-angle, and a cam 67 thereon operates linkage 68, 70, 71 for shifting or unshifting the type-wheel. The type-wheel is maintained in contact with an upper or lower stop by a spring 75, or a spring in connection with the arm 71. Letter-spacing mechanism. The tape T passes between a feed-roller 56, and a pressure-roller 57 carried by a spring-urged bell-crank. The feed-roller has pawl-connection 54, Fig. 3, with the shaft of a pinion 53 co-operating with a sector 51 abutting on an arm on a rock-shaft 49 which is connected to another rock-shaft 47 by a link 48. The rock-shaft 47 is provided with an arm 46 having a pin 58 which abuts on the bail 33. When the hand-lever is depressed for typing, the bail 33 rocks the arm 46, a spring 52 actuates the sector, and the pawl 54 is retracted. On release of the hand-lever, the pawl effects rotation of the feed-roller, and the tape is letterspaced. For word-spacing, the handle is moved into extreme right-hand position to permit direct co-operation with the arm 46. To provide for variable spacing, corresponding to the widths of different letters such as M, I, the type-wheel shaft is provided with a disc 59 having notches and projections 60, 61 which co-operate with a lug on the sector 51 to limit variably the retraction, and consequently, the feed-movement, of the pawl 54. Web-feeding arrangements. To permit of the tape T, Fig. 1, being fed intermiftently and continuously for letterspacing and scanning respectively, a loop 20 is arranged in the tape. When the message has been typed, and the last part thereof is being transmitted, the loop is taken uo and the pressure-roller 57 is displaced, further letter-spacing operations being thereby prevented. Specification 543,023, [Group XL], is referred to in the Provisional Specification.