GB529983A - Improvements in or relating to power driven typewriters - Google Patents

Abstract

529,983. Typewriters. CREED & CO., Ltd., THOMPSON, A. E., and SALMON, R. D. May 30, 1939, No. 15920. [Class 100 (iv)] Relay type - wheel actions. In a keyboardcontrolled poweroperated typewriter, a type-wheel is stopped in character - selecting position by key-controlled detents which are moved successively into co-operation with rotatable rows of stops to select progressively and directly the character to be printed. The type-drum 17 shown in the Figure is splined on a shaft 20 geared to a sleeve 3 which is frictionally mounted on a driving-shaft 2 and is provided with rows 3a ... 3d of stops for co - operation with pivoted detents 4a ... 4d. The stop 3d has four equi - distant arms arranged at an angle of 45 degrees to a double arm constituting the stop 3c, and to single, opposite arms constituting the stops 3a, 3b. The detents 4b ... 4d have arms for co-operating with interponents 10 pivoted to combination bars 11b ... 11d controlled by the keys. The interponents co-operate with cams on a sleeve 9 which is driven through a one-revolution clutch at half the speed of the shaft 1, the cams being angularly spaced in correspondence with the stops 3a ... 3d. The detents co-operate with a latch 27 which engages a cam-operated lever 26. If the combination bar 11a is fully displaced, the associated camoperated interponent 10 rocks the detent 4b, the latch 27 is depressed by the detent 4b to release the detent 4a, and the sleeve 3, after making a half-revolution, is arrested by co-operation of the stops 3b, and detent 4b. Similarly, if the combination bars 11a, 11b are fully displaced, the sleeve is arrested by the stop 3b and detent 4b, and then by the stop 3c and detent 4c,. the total movement of the sleeve being threequarters of a revolution. If all the combination bars are fully displaced, the stop 3d and detent 4b also become effective, and the sleeve makes a total movement of seven-eighths of a revolution. After operation of a printing hammer by a cam on the sleeve 9, the detent 4a and latch-lever 26 are operated by other cams, and the sleeve and type-wheel are arrested in initial position. The apparatus may be associated with tape-perforating mechanism, the punches being operated individually by the cams that operate the interponents 10. Alternatively, the sleeve 9 may be provided with a cam for operating a punchblock. Signal-transmitting mechanism under control of the perforated tape or the combination bars may be driven by the same motor as the above-described apparatus. Case - shift mechanism. A type - drum 17 is shifted axially by means of a slide 16 provided with a roller 15 co-operating with a helical cam 14 or a snail cam which is rotated through a variable angle under control of stops 2a ... 2d and detents 5a ... 5d operating in the same manner as the stops 3a ... 3d and detents 4a ... 4d. Alternatively, shift keys may be arranged to operate the type-drum directly.