A locking electrical cord connector includes both male and female contacts. The device includes a housing of electrically non-conductive material including a cylindrical cavity. A pair of opposed plungers are mounted for reciprocation in this cavity. An actuator switch in the form of an elliptical disc...http://www.google.es/patents/US5108301?utm_source=gb-gplus-sharePatente US5108301 - Locking electrical cord connector
