A dimmer switch assembly consists of a conductive yoke which has two insulation housings connected thereto which carry respective subassemblies for the dimmer switch. The first insulation housing contains a rotatable push shaft. Shaft rotation rotates a resistor plate having a resistive pattern on its...http://www.google.es/patents/US4520306?utm_source=gb-gplus-sharePatente US4520306 - Wall mounted electrical voltage control switch
