GB1436484A - Alternate action switch mechanisms - Google Patents

Abstract

1436484 Push-button switches ILLINOIS TOOL WORKS Inc 22 May 1974 [23 May 1973] 22915/74 Heading H1N An alternate action switch mechanism for operating switch contacts (not shown) and which can be easily converted to retractive action merely by removal of a wire cam follower, comprises a housing having an outer surface 14 with an aperture 18 therein and a projection 50 (Fig. 3) extending parallel to surface 14, an actuating member 20 mounted for movement in the aperture 18 between an initial position and a second position, spring means (38, Fig. 2, not shown) for biasing member 20 towards its initial position, the member 20 having a cam 34 associated therewith, an elongated wire cam follower 44 having a portion 44c located under the projection 50 to prevent the cam follower 44 being released from the housing during switch actuation, the major length of the cam follower being located on the exterior of the housing to be readily removable when retractive switch action is desired, a first end 44a being pivoted in the housing, and a second end 44b serving as the camfollowing portion being positioned to interact with cam 34 so that the cam follower 44 rotates under projection 50 and over the surface 14 during actuation and holds the member 20 in its second position after a first actuation in the direction from initial to second position, and releases the member 20 to its initial position after a second actuation in the same direction. As shown, the member 20 comprises a plunger and contacts the sides of aperture 18 only at surfaces 24 in order to reduce friction. Cam 34 is integral with an extension 32 of plunger 20 and comprises a conventional closed-loop slot (35, Fig. 4, not shown), the profile of which is described in detail (Figs. 5 to 8, not shown).