| 摘要 |
<p>997,288. Keyboard switches. W. HOLZER. Jan. 26, 1962 [Feb. 14, 1961; Dec. 27, 1961], No. 3072/62. Drawings to Specification. Heading H2B. A plurality of spring-loaded slides each having a push button on one end and a plurality of cams along their length are arranged adjacently to pass through respective apertures in a plurality of spring-loaded transverse slides. Depression of a push button causes transverse movement of certain transverse slides (according to the arrangement of cams on the slide of the selected push button) to operate switch contacts for a programme sequence of a machine tool, for example. A special transverse locking slide prevents the buttons with their slides being removed from the transverse slides but overriding means is provided to permit removal so that further slides having different arrangements of cams can be utilized. In one embodiment (Fig. 10, not shown) an extra large cam adjacent each push button moves the locking slide when a button is held fully depressed and allows any other button with its slide to be removed. In another embodiment (Fig. 11, not shown) two locking slides are oppositely spring-urged such that overlapping apertures prevent the withdrawal of cammed slides therethrough unless a bladed tool is inserted against bent-up lugs or tapered recesses (Fig. 13, not shown) on the locking slides to align the apertures.</p> |
