GB1449637A - Switching device - Google Patents

Abstract

1449637 Stop- and release-devices for rotary members; definite positions PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 10 Oct 1973 [13 Oct 1972] 47291/73 Heading F2E The invention in its broadest aspect is exemplified by the following description. Figs. 1 to 4 are underneath views of Fig. 5. As shown in Figs. 1 and 5, a knob 9 located on a mounting plate 1 has a control spindle 5 extending through the plate 2, the knob and spindle being rotatable with, and also rotatable relative to, a drum 3. The lower end of spindle 5 has lateral projections 35, 35<SP>1</SP> which retain a slide 13 and, as best shown in Fig. 4, can move the slide by stop surfaces 37, 37<SP>1</SP> (see below). The slide has slots 31, 33, 31<SP>1</SP> in which are located a pin 11 extending down from the drum, the spindle 5, and a further pin 11, respectively; it also has stepped arcuate surfaces (one shown at 19, Fig. 4) at one end which may be aligned with arcuate surfaces 21, Figs. 2, 4, formed in a cutaway portion of the drum. A latching pin 23 on a latching lever 25 pivoted at 27 is urged constantly into engagement with one or other of surfaces 19, 21, by a spring 29, and in the "off" position of Fig. 1, a stop roller 41 mounted by a spindle 53, Fig. 2, on a slide 43 is urged by a spring 47 into a cavity 39 of the drum. In operation, if knob 9 is rotated from the Fig. 1 position in the direction 49, Fig. 2, the slide, and hence the drum, rotate with it, and pin 23 eventually engages a latching cavity 51 formed at the right of the end of the slide. When the knob is released, the assembly is retained in the Fig. 2 position because though the drum is being urged by spring 47 clockwise via roller 41, whose spindle 53 lies within the angular extent of cavity 39 (see flank 55), the drum is retained by pin 23 engaging slide 13. The knob may be rotated further in direction 49 to the Fig. 3 position, where pin 23 engages a stop surface 61, and the knob is retained to hold this position. On release of the knob a spring, not illustrated, returns the assembly to the Fig. 2 position. To regain the "off" position, from the Fig. 2 position, the knob is rotated with increased force in direction 49<SP>1</SP>, whereupon the spindle 5 rotates relative to the drum so that one projection 35<SP>1</SP> retracts the slide against the force of the springs 15 by means of one stop surface 37<SP>1</SP> until surface 19 is aligned with drum surfaces 21, Fig. 4. Thereafter, the drum rotates also, bringing slide surface 19 into contact with pin 23 until stop roller 41 engages cavity 39. On release of the knob, springs 15 restore slide 13 to the Fig. 1 position. Similar actions occur on rotation of the knob in the reverse direction. The invention is applicable to record-player switches.