GB1243640A - Selectively operable mechanism for keyboard operating machines - Google Patents

Abstract

1,243,640. Keyboards. INTERNATIONAL BUSINESS MACHINES CORP. 31 Dec., 1968 [10 Jan., 1968], No. 61800/68. Heading B6F. Keyboard interlocks.-A keyboard 10 has an interlock member 16 provided with detents 108 which can co-operate with key-stem pins 109, 1091 to selectively lock keys 107, 107<SP>1</SP>. The interlock member 16 is slidably movable to control selectively the operation of the keys. An interposer 33, slidably mounted by pins 34 on the interlock member 16, is moved from its inoperative position to its operative position by depressing key 110. In the depressed operative position, the lower extension 111 of the interposer 33 is engaged by alug 18 of an actuator 20, cyclically movable first in the direction of arrow A and then in the opposite direction. The actuator 20 therefore moves the interposer 33 in the direction of arrow A, which in turn moves the interlock member 16 from its normal position to a selected operating position in which the detents 108 are moved out of alignment with key-stems 109, 109<SP>1</SP>. A spring loaded latch 45 retains the interlock member 16 in the selected operating position. Key 107 is thereafter free to be depressed until such time as key 107<SP>1</SP> is depressed. When key 107<SP>1</SP> is depressed, its keystem pin 109<SP>1</SP> co-operates with a cam 52 on a slider 17 (Fig. 2) thereby moving the slider in the direction of the arrow A. A further cam 50 on the slider 17 co-operates with the latch 45 to release the interlock member 16, which returns to its normal position under the action of spring 27, thereby blocking keys 107 and 107<SP>1</SP>. In an alternative embodiment (Figs. 4 and 5), an additional interposer (88) is provided instead of cam 52, Fig. 1, on slider 17 (75), to provide the movement of the slider in the direction of the arrow A. In this alternative embodiment, this movement is therefore derived from the cyclically moving actuator (105). The latch for the interlock member is released in a similar manner to the previous embodiment by a cam (100). In this alternative embodiment, a detent (121) on the interlock member (74) comes into alignment with a key-stem pin (122) when the interlock member is in its selected operating position and not its normal position.