GB342558A - Improvements in power-actuated typewriters - Google Patents

Abstract

342,558. Typewriters. WADE, H., 111, Hatton Garden, London.-(Electromatic Typewriters, Inc.; 60, Commercial Street, Rochester, New York, U.S.A.) Feb. 28, 1930, No. 6675. [Class 100 (iv).] Relay actions ; carriage and case-shift mechanism. -In mechanism comprising a relay device which on depression and release of a key is operated twice to shift and return a paper-carriage, type-basket, or other member, the direction of movement of the member is positively determined by means of a key-controlled interponent, the arrangement preventing the member from being moved in the wrong direction in an operation following one in which the relay device has failed to act. In the carriage-shift mechanism shown in Fig. 1, the carriage 11 is supported at each end of rocking arms 13, 14, one of the arms 14 being connected to the framework by a toggle 17, 18, which is connected to the framework by a toggle 20, 21. Pins 36, 37, arranged on the toggle arm 21 at equal distances from the pivot 22, co-operate with an interponent or head 35 on a link 34 which is carried by a bell crank 31 and has a pin 43 engaging a slot in a shiftkey lever 39. The bell crank is connected by a link 30 to a lever 27 carrying a cam 29 which is controlled by the shift-key lever and co-operates with a driving-roller 26 in the manner described below. On depression of the shift-key lever, the link 34 is depressed, the cam engages the driving- roller and makes a half-revolution, the lever 27 and bell crank 31 are rocked, the head engages the pin 36 and moves rearwardly the toggle arm 21, and the carriage is shifted upwards. A dwell in the cam then permits a spring 32 to return the bell crank into engagement with a stop 33. On release of the shift-key lever, the cam again makes a half-revolution and the head co-operates with the pin 37 to return the toggle arm 21 and thereby lower the carriage into the normal position. The shift and return movements of the carriage are limited by the straightening of the toggles 20, 21 and 17, 18, respectively, positive stops being dispensed with. The carriage is balanced by a spring 25 connected to elbows 23, 24 on the arms 13, 14, the elbows moving out of alignment when the carriage is raised. The cam is urged into engagement with the driving-roller by means of a spring-urged lever 46, Fig. 4, co-operating with either of a pair of pins 45 on the cam, movement being normally prevented by engagement of either of a pair of lugs 52 on the cam with a detent 51 on a lever 49 having a lug 53 engaging a fork 41 on the shift-key lever. On depression of the shift-key lever, the cam engages the driving-roller and after making a half-revolution is arrested by engagement of one of the lugs 52 with a detent 50 on the lever 49. On release of the shift-key lever, the cam is again moved into engagement with the driving-roller, and after making a half-revolution is arrested by the detent 51.