Patent GB-151036-A (GB)
Title: Improvements in pneumatic operating means for typewriters and the like
IPC: B41J23/20
Filed: 1919-10-10
Abstract: 151,036. Reynolds, R. April 10, 1919. Pneumatic typelever actions.-Singl@acting valves, arranged below a keyboard and operated. directly by the keys, control relay valves in connexion with pneumatics for operating the type-levers ; for printing words or combinations of letters, some of the type-lovers may be arranged to strike successively upon depressing a single key. In the mechanism shown in Fig. 1, valves n, operated by touch-keys m consisting of spring-returned plu@- gers, control the admission of air to tubes o connected to individual pneumatic devices consisting of a suction-chamber a, a diaphragm l, a doubleacting valve e, and bellows b connected by a link h to a bell-crank which is connected to a typelever. On depressing a key, the valve n permits air to pass into the space below the diaphragm of the associated pneumatic device, and the valve e then closes a port f and opens a port c, thereby causing the bellows to collapse and operate the type-lever. The arrangement for printing a word or a combination of letters upon depressing a single key 30 is shown in Fig. 4. The pneumatic devices for operating the type-levers that print the word &c. are connected to tubes which are normally by flap valves 67 - - 70. A cam 55 for operating the flap-valves is formed on a slide 54, which is connected by linkage 46, 45 to the rocking plate 43 of double bellows 42. The slide is mounted on a bar 49 which is pivoted at one end 50 and is connected bv a link 52 to bellows 59. A pneumatic device 73. consisting of a suction-chamber 40, double-acting valves 36, 37, and diaphragms 34, 35 is connected by tubes 38, 39 to the bellows 42, the tube 39 being connected also to the bellows 59. The key 30 operates a valve 31 controlling the admission of air to a tube 33 which communicates with the space below the diaphragms. An adjustable choking-aperture. 72 is provided for causing the bellows 42 to lag behind the bellows 59. On depressing the key the tubes 38, 39 are placed in communication with the atmosphere and the suction-chamber respectively, thereby causing the bellows to elevate the bar and the slide, and the bellows 42 to move the slide to the left. During the movement, the cam 55 operates the valves 67 - - 70. and the type levers are caused to strike successively. When the word &c. has been printed the key is released, thereby causing the tubes 38 39 to communicate with the suction chamber and the atmosphere respectively. The bellows 59 then lowers the bar and the slide and, after a short interval, the bellows 42 returns the slide 54. The cam 55 is inoperative, during the return movement of the slide. The suction chambers are connected to exhausting-bellows, operated by a pedal or motor. The keyboard may be arranged in the usual position. The typewriter desk may contain the pneumatic mechanism. Pneumatic letter-spacing mechanism.-The carriage 13, Fig. 1, is geared to a shaft 12 which is geared by a chain 15 to a pneumatic driving-motor 18. The shaft is provided with escapement wheels 8, 10 which co-operate with a tooth 7 on a rocking plate 6 forming the division plate of double bellows t controlled by the printing-keys m, described above, and a spacing-key 21. The two chambers of the bellows are connected by tubes w, x to chambers u, v, containing valves y, z which are arranged above a suction chamber 4 and are operated by diaphragms 1. 2. The space below the diaphragms is connected by a tube 3 to a chamber p which is connected to a tube r and to tubes q, the tube r being closed by a valve 22 operated by the spacing-kev 21. and the tubes q being closed by valves j operated by adjustable tappets on the links h. On depressing the spacing-key, the valves y. z place the tubes x, w in communication with the atmosphere and the suction chamber respectively and the plate 6 is rocked to the left, and on releasing the spacing- key the valves place the tubes w, x in communication with the atmosphere and the suction chamber respectively, and the plate is rocked to the right. On depressing and releasing a printing- key, the associated tappet i opens and closes a valve j and the plate 6 is operated in the abovedescribed manner. Adjustable stops 11 are provided for the plate 6.