Electrical male plug lock
Patent 5507656 Issued on April 16, 1996. Estimated Expiration Date: 
October 28, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 28, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2664734 2733416 Locking device for the prongs of an electrical plug Lockout device for electrically operated equipment and devices Electric plug lock Apparatus for preventing the use of an electrical device Electrical plug safety lock Patent #: 5277600 InventorApplicationNo. 328781 filed on 10/28/1994US Classes:439/133, WITH UNAUTHORIZED CONNECTION PREVENTER, E.G., KEY OR COMBINATION LOCK439/134Prong coverExaminersPrimary: Bradley, P. AustinAssistant: Wittels, Daniel Attorney, Agent or FirmInternational ClassH01R 013/44AbstractThe invention is a lock for male electrical connectors used with appliances and power equipment and consists of a housing with receiving slots for the connector prongs and a U-shaped spring in the housing containing nibs that engage the apertures on the connector prongs. A spring biased plunger engages the arms and cause them to release the prongs when depressed. Cooperating holes through the housing and the plunger allow a lock to pass through and disable the plunger. The spring biasing the plunger is selectibly changeable for situations where a stronger spring would negate the use of a lock. The housing is sufficiently thin that a three conductor plug could be locked without interference from the ground prong. | |
