Patent GB-457107-A (GB)
Title: Improvements in or relating to typewriting machines
IPC: B41J11/70
Filed: 1935-05-20
Abstract: 457,107. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION, 270, Broadway, New York, U.S.A.- (Assignees of Thompson, R.G.) May 20, 1935, No. 14713. Convention date, May 25, 1934. [Class 100 (iv)] Web cutting and guiding arrangements.-A typewriter having mechanism for returning the carriage to a starting position is provided with a paper-cutting device which is operative during return of the carriage. The mechanism described below is for use in typing one-line entries on checks or tickets which are cut off a web, the platen being rotated to feed the web before the carriage is returned, and the check being cut off by means of a knife- and-disc cutter during return of the carriage. The web 114, Fig. 2, passes between a guide-strip 103 and a knife-blade 102 which are arranged above the platen 30 and are secured to a flange 101 on a plate 99 forming part of a box 95 secured to a shelf 34 on the carriage 21. The web is guided laterally by the sides 98 of the box and is engaged by spring guides 99a secured to the plate 99. A cutting disc 112, co-operating with the knife-blade, is journalled on a spring-urged arm 109 which is pivoted at 108 on a bracket 106 secured to the coverplate 105 of the machine. Initially, the end of the web coincides with the edge of the knife-blade. During typing of a line on the web, the cutting-disc is ineffective, and at the end of the line the space-bar is operated to move the web clear of the cutting-disc. To avoid operation of the space-bar, the escapement-rack 43 may be formed with a gap for causing the carriage to jump at the end of a line. When, as described below, carriage-return is initiated, the platen is rotated to feed forward a check-length of the web, and when the carriage is returned, the cutting-disc and knifeblade co-operate to sever the check. The severed check drops into a pocket formed by the plate 99, sides 98, and ears 100. The shelf 34 is mounted on pivots 33 and can be turned backwards, with the box 95, to disable the cutting-device. Carriage-returning mechanism; platen -rotation for blanking.-The carriage 21, Figs. 2 and 5, is provided with the carriage-returning mechanism shown in Fig. 5 and comprising a drum 50 connected by a tape 51 to the carriage and adapted to be coupled by a friction-clutch to the shaft 15 of a driving-roller 12 which operates the relay type-lever action described in Specification 266,921, [Class 100 (iv)]. A clutchoperating arm 49 is connected by a toggle 48 to a bell-crank 46 which is connected to the carriage-returning key-lever 65 and is provided with a cam 45 for co-operating with the driving- roller. On depression of the carriage-returning key 44, or on engagement of the margin stop 28 with a lever 53 connected by linkage 62, 64 to the lever 65, the toggle is straightened, the drum is coupled, and the carriage is returned. The margin stop 29, shortly before engaging the lever 53 to arrest the carriage, rides up an incline 55a on a lever 55, a bell-crank 59 connected thereto breaks the toggle, and the drum is uncoupled. The tape is wound on a spring drum 70, Fig. 3, which is loosely mounted on the shaft 31 of the platen 30 and is provided with a pawl 73 for co-operating with diametrically opposite lugs 77 on a disc 75 secured to the platen. Dogs 79, 80, pivoted on the carriage, have lugs 81, 82 which normally engage the lower of a pair of diametrically opposite lugs 76 on the disc and thereby lock the platen. When carriage-return is initiated, the spring drum 70 is turned two-thirds of a revolution by means of the tape 51 before the carriage begins to move. When a stop 93 on the spring drum has receded slightly from the lug 81 the edge 94 of the pawl strikes the lugs 82, 81, thereby releasing the lower lug 76, the pawl engages the lower lug 77 and turns the platen half a revolution, the other lug 76 is caught by the lugs 82, 81, and the platen is again locked. Thereupon, the carriage begins' to move, and on completion of the movement the spring drum is returned to normal position, the pawl 73 passing idly over the lower lug 77. During rotation of the platen, the web 114, held in contact with the platen by the usual feed-rollers 40, 41, receives a feed equal to half the circumference of the platen. To permit of manual, counter-clockwise rotation of the platen, the dogs 79, 80 are depressed slightly by means of a release-lever 87.