| 摘要 |
1388837 Mechanical switches; switch cases RYFORD Ltd 24 May 1972 [16 June 1971] 28084/71 Heading H1N A moulded assembly for forming an electrical contact assembly comprises an insulating base member 10 of thermoplastic resin grooved, as at 15a to 15d, to receive one or more conductive strips, as 12a to 12d, and a cover member 11 of similar material to base 10 and grooved to receive a corresponding number of conductive strips, as 13a to 13d, overlying the fixed strips 15a to 15d so as to be resiliently displaceable into and out of contact with the latter, a spacer 14 being provided between the base and cover members 10 and 11 to provide insulation between the fixed and displaceable strips, when the strips are in position in the moulded assembly, except where the strips are to contact each other, and at least one of said base or cover members has integrally formed means capable of retaining associated conductive strips in position prior to the assembly of the members and spacer, said means including undercut projections on the walls of the grooves with tapered lead-in portions whereby suitably sized conductive strips may be snap-engaged with the grooves. Preferably both cover and base have retaining means which, as shown, comprise a pair of barbs 17 in each groove providing a snap fit of a conductive strip in the groove. Cover 11 has four posts (25, Figs. 6 and 7, not shown) which mate with holes 26 in the base 10 (or vice versa) and are deformed by heating to secure the assembly. The posts (25), which pass through holes in spacer 14, may be replaced by rivets passing through aligned holes in cover, base and spacer. To allow formation of barbs 17 by moulding, adjacent apertures (19, Fig. 1, and 23, Fig. 9, not shown) are provided for core members of the moulding die. |
