GB270451A - Improvements in or in connection with electric switching devices - Google Patents

Abstract

270,451. Davies, F., and Macgregor, L. D. March 4, 1926. Fress-button switches; quick-action switches with compound movement.-A rotary switch adapted for putting two circuits in series or parallel, or cutting out one circuit, comprises moving and stationary parts, engaging by spring- pressed clutch surfaces on a central spindle and bush in order to ensure definite settings. The switch may be combined with condensers, inductances, or resistances. In a switch combined with two filament resistances R. R<1> the latter are mounted on an insulating cylinder I. The terminals T, T<1> are attached to metal plates D, D<1> separated by an insulating plate I<1> and clamped by a washer I<2> and nut L which secure the cylinder I on a bush G. An insulating plate A mounted on a bush B<1>, which passes through the bush G. carries fingers W. W<1>, which make contact with the plates D, D<1> respectively. The finger W<1> and a third finger W<2> move over the resistances R, R'. An insulating plate E is carried by a bush B<2> mounted on a spindle N. the upper end of which carries a spring-pressed button O slidable but not rotatable in a knob K. The bushes B<1>, B<2> engage by ratchet surfaces, and when the knob is turned in one direction the plates E, A move together and the fingers W', W<2> are moved over the resistances. When the knob is turned in the other direction the ratchet surfaces slip when stops V, V<1> on the cylinder I and plate A engage. Two wipers X are then moved over the plate A, which has contacts C<1>, C<2>, C<3> connected to the finger W, contacts C<4>, C<5> connected to the finger W<2>, and a contact C<6> connected to the finger W. The joint between the ends of the resistances R, R<1> is in connection with a contact C' by means of a stud U<3>. spring S<1>, plunger J. bush G, and bush B<1>. When C' is joined to C<7> and C<5> to C<6>, the resistances are in parallel; when C<2> is connected to C<7> the resistance R<1> is cut out, and when C' is connected to C<4> the resistances are in series.