Patent GB-436617-A (GB)
Title: Improvements in tabulating mechanism for printing telegraph apparatus
IPC: H04L17/22
Filed: 1934-12-20
Abstract: 436,617. Printing-telegraphs. CREED & CO., Ltd., Telegraph House, Croydon.- (Assignees of Reiber, A. H., Burcky, C. W., and Lake, R. A.) Dec. 20, 1934, Nos. 36549 and 36550. Convention dates, July 14. [Class 100 (iv)] Tabulating-mechanism; letter-spacing mechanism; carriage-releasing arrangements.-In printing-telegraphs having a carriage which is movable for letter-spacing under control of escapement-mechanism comprising a pair of spring-urged pawls, a tabulator-function lever disables one of the pawls to permit of free movement of the carriage for tabulating. Provision may be made for preventing release of the carriage, and operation of the printing and spacing mechanisms when the carriage reaches line-end position. The apparatus shown in Figs. 2 and 3 comprises as described in Specification 365,975, a type-carriage 15 supporting type-levers which are selected and operated by means of code-bars 14, selectorvanes 107, and a printing-bail 43 mounted on the stationary framework. The apparatus comprises also letter-spacing mechanism consisting of a three-toothed escapement-wheel 52 co-operating with spring-urged pawls 62, 63 operated by an arm 64 on the printing- bail 43. The escapement-wheel is frictionally coupled to a driving-shaft 21, and is provided with a worm engaging a worm-wheel 28 on a shaft 29 geared to the type-carrage 15. During the printing stroke, the pawl 62 is released and the pawl 63 locks the escapement-wheel, and during the return stroke, the pawl 63 is released and the escapement-wheel, after making a third of a revolution, is again locked by the pawl 62. The apparatus is now provided with tabulating-mechanism comprising a spring-urged tabulating-bar 81 which can rock on pivots 181 on the stationary framework and is provided with adjustable columnstops 86 arranged, when the tabulating-bar is in rear position, to engage a one-way stop 111 on the type-carriage 15. The columnstops have cam-edges 89 which co-operate with the stop 111 to return the tabulating- bar. An arm 92 on the tabulating-bar is formed with a slot 93 having a shoulder 94 which normally abuts on a finger 101 on a lever 97 to hold the tabulating-bar in forward position. The lever is provided with a forked arm 103 engaging the pawl 62. When the tabulating-signal is received, the selectorvanes 107 permit the tabulator-function lever 45 to move forwards, an arm 106 thereon rocks the lever 97, the pawl 62 is disengaged to release the type-carriage, and the finger 101 rides off the shoulder 94 to permit rearward movement of the tabulating-bar. The released type-carriage moves continuously until the stop 111, by co-operation with the adjacent column-stop, moves forward the tabulating-bar, whereupon the lever 97 returns to normal position, and the arm 103 permits the pawl 62 to re-engage the escapementwheel and arrest the type-carriage. The tabulating speed of the type-carriage is three times the letter-spacing speed, since the worm in connection with the escapement wheel makes one revolution for each revolution of the shaft 21. To prevent jamming if the tabulating-signal is received after the typecarriage has reached the end of a line, the arm 92 is provided with a latch 121 having a finger 127 adapted to obstruct the lever 97, and thereby prevent release of the typecarriage, when the tabulating-bar is moved abnormally by co-operation of the stop 111 with a line-end stop 125 on the tabulating-bar. To prevent operation of the printing and spacing mechanisms when the type-carriage has reached the end of a line, the tabulating- bar is provided with an arm 128 having a lug 129 which normally obstructs a spring- urged lever 133, When the tabulating-bar is moved abnormally at line-end by means of the stop 111, the lever 133 is released, an arm 136 thereon moves into the path of a shoulder 137 on a bail 40, and the bail 43 is thereby prevented from making an effective movement.