| 摘要 |
A snap-action fastening device for control and/or signalling unit comprises a sleeve (1) with a shape corresponding to and suitable for cooperating with a cantilevered rear portion (40) of an operating unit (4) equipped with shaped surface grooves (41), said sleeve having a shape complementary to that of said rear portion of the operating unit slipped as a bayonet into said sleeve, the internal surface of the latter being provided with ridges (10) making part of said bayonet coupling, the outer surface of the said sleeve being partially threaded, a ring nut (2) threaded to the outer surface of said sleeve, means for securing electrical elements (7) of the control and/or signalling unit to said sleeve, said securing means comprising a separated annular element (3) interposed between said sleeve (1) and said electrical element (7), said annular element (3) being suitable for engaging, by snap-action means, some stop means (12, 13, 14, 15) provided on the sleeve, and being equipped with means for releasably securing said electrical elements. |
