GB1359771A - Miniature oil-tight pushbutton and selector switch assembly and contact unit therefor - Google Patents

Abstract

1359771 Mechanical switches SQUARE D CO 1 May 1972 [4 May 1971] 20073/72 Heading H1N An electric switch assembly comprises an operator housing 16, Fig. 3, through which a push button 14 (shown) or a rotary operator extends to carry removable cam 29 controlling contacts 99, Figs. 12, 13 in housings 67 or (156), Fig. 18 (assembly not shown), secured to the rear end of the housing 16. The cam 29 may have up to four operating faces 122, 125, Fig. 9, co-operating with projections 109 on radially moving cam sliders 87 in up to four contact housing units 67 which operate to separate or release contact pairs 99 by engagment of curved faces (106), Fig. 14 (not shown), with bosses 97. The cam 29 is keyed against relative rotation on the button end 25 but may be clipped on at spring lips 63b with either end forward whereby "normally off" and "normally on" conditions may be selectively obtained for any or all of the contact units from a minimum number of different cams 29. The radial sliders 87 are urged resiliently inwardly by torsion springs 120 which operate via intermediate rocking indicator units 86 having indicia visible through an aperture 116 in each contact unit 67 to indicate the open or closed condition of the relevant contact set 99. The contact units 67 are attached to the rear of the casing 16 by screws engaging threaded apertures (36), Fig. 2 (not shown), and are also positively located by projections (30), Fig. 11 (not shown), on the units engaging recesses (34), Fig. 2 (not shown), on the housing 16. In a modification in which the contact sets in units 22, Fig. 31, are operated by cams as 212f or 212r on the end of a rotary actuator 165 the cams as (212a), Fig. 27 (not shown), or 212b, Fig. 28, may be shaped to give any number of normally close contact positions C or normally open positions O and may be initially mounted in selectively rotatable positions on the shaft 211 whereby a selected programme of switching the four contact units 22 may be obtained. As shown in Figs. 12 and 31, the radial sliders may be mounted with the projection 109 towards the front or may be turned over to positions 109a whereby the cam 212f or 212r may be selected for operating any one or more of the contact units 22. The rotary spindle actuator 165 may be coupled to the cam or cams 212 via a splined member 185, Fig. 23, (part) having recesses 192 for spring loaded detents 169 arranged to locate the actuator 165 in up to eight different positions. Movement of projection 196 on the member 185 within a slot 210 of a predetermined length in a fixed washer 171 determines the angle through which the actuator may be rotated and thereby the number of operative positions. In a modification some of the recesses 192 may be omitted and the actuator made retractive to a centre stable position by a torsion spring (224), Figs. 34, 37 (not shown), having radially projecting ends (226) engageable with stops (230). Lamp units such as (130), Fig. 18 (not shown), may be mounted in central apertures 126 of the push button 14 or rotary actuator 165 and have terminal contact lugs (144) rotatably or slidably engageable with fixed terminals (162) of lamp terminal units as (156), Fig. 16 (not shown), which may be attached to the rear of the switch housing 16 in place of two of the contact units 67. See also provisional Specifications 1,359,772 and 1,359,773.