| 摘要 |
1,188,454. Mechanical switches; retractive switches. TELEPHONE MFG. Co. Ltd. 30 Jan., 1969 [14 Feb., 1968], No. 7262/68. Heading H1N. A push-button switch comprises a housing 20, a push-button 1, 2, 3, depressible against restoring spring 14, an actuating plate 8 pivotally mounted at one end 10, a spring 13 acting between the end 3 of the push-button and actuating plate 8, and at least one microswitch 12 arranged to be actuated by pivoting movement of actuating plate 8 in response to movement of the push-button. As shown, two microswitches 12, 27, Fig. 2 (not shown), are provided side by side. A lampholder is mounted within the push-button by leads 23, 24 forming terminals 25, 26 at their lower ends. A push-on, push-off latching mechanism may be provided comprising a cam track 21 in the end 3 of the push-button, and a pin 19, Figs. 2, 4 (not shown), rides in the cam track, is supported on the housing and is spring-biased to the left of Fig. 1. When the push-button is depressed pin 19 rides up the right hand half of the cam track 21 and latches in the top, when the push-button is depressed again pin 19 rides out of the top of the cam track and down the left hand half to its original position. A mutual interlock latch may be fitted comprising a cam track forming two notches, Fig. 6 (not shown), in the end 3 of the push-button, when the pushbutton is depressed pin 19 rides into the top notch and remains there until freed by depressing another push-button in an assembly of push-buttons. When the push-button forms part of a group a mechanism may be fitted so that only one push-button can be operated at a time, comprising a pin 34, Figs. 2, 2a, 5 (not shown), which acts as an interference piece between a series of balls, discs, plates, or the like which have a total freedom of sideways movement such that only one pin 34 can be depressed to fit between them at a time. Coil spring 13 may be replaced by a leaf or blade spring 51, Fig. 7 (not shown). Two further microswitches may be fitted vertically below microswitches 12, 27. These are operated by a push-rod 52, Fig. 8 (not shown), depressed by actuating plate 8 and in turn depressing a further actuating plate through a further spring. |
