Tamperproof switch

Claim 2

A tamper proof key operated electric switch comprising a housing; a switch mechanism carried by the housing, said switch mechanism including an actuator moveable along a predetermined path to a first position in which the switch is in one condition of operation, and a second position in which the switch is in another condition of operation; said switch mechanism including key receiving means to receive a key for moving the actuator to said positions; blocking means in the housing; a blocking element within the housing and moveable with respect to the actuator to a blocking position in which the blocking element cooperates with the blocking means to prevent movement of the actuator, and a released position in which the actuator can be moved from one of its positions to the other; spring means for urging said blocking element toward its blocking position; said blocking element having surface means positioned for engagement by a key inserted in said key receiving means for moving said blocking element to said released position so that said actuator can be moved to said positions upon insertion of the key.

Claim 3

A tamper proof switch according to claim 1 wherein said blocking means includes a pair of blocking lugs at opposite sides of said actuator; and said blocking element includes a pair of tabs which in said blocking position of the blocking element, cooperate with said lugs to prevent movement of the actuator.

Claim 4

A tamper proof switch according to claim 1 which further includes means mounting said actuator for pivotal movement; and means mounting said blocking element on said actuator for movement with the actuator; said blocking element presenting a pair of key engagable surfaces exposed with respect to said key receiving means to enable moving said blocking element to its released position upon insertion of a key.

Claim 5

A tamper proof switch according to claim 1 wherein said spring supports said blocking element for tilting movement with respect to the actuator; and cooperating means on said actuator and blocking element for locking said blocking element against movement to its released position upon tilting of the blocking element.

Claim 6

A tamper proof switch according to claim 1 wherein said blocking element includes surface means for engagement by a key at two spaced apart locations; said spring supports said blocking element for tilting movement; and means extending along the path of travel of the blocking element between its released and blocking positions to lock the blocking element against movement to its released position, in response to tilting of said Blocking element.

Claim 7

A tamperproof key operated electric switch comprising housing means; switch contacts within the housing means; an actuator within the housing means mounted for pivotal movement to a first position in which the switch contacts are opened, and second position in which the switch contacts are closed; means defining a slot opening through the housing means for insertion of a key to operate the actuator; blocking means within the housing means; a blocking element; means on said actuator mounting said blocking element for pivotal movement with the actuator and for movement with respect to the actuator, in a direction generally radially of the direction of pivotal movement of the actuator; said blocking element being moveable in said radial direction to a blocking position in which the blocking element cooperates with the blocking means in the housing to prevent pivotal movement of the actuator, and; a released position in which the actuator can be moved from one of its positions to another; spring means for urging said blocking element toward its blocking position; said blocking element having surface means positioned for engagement at two locations by a key inserted through said slot for moving said blocking element to said released position; and means on said actuator for connecting a key inserted through the slot to the actuator for movement therewith to pivot the actuator and switch the switch contacts.

Claim 8

A tamperproof key operated electric switch comprising housing means; switch contacts within the housing means; an actuator within the housing means mounted for pivotal movement to a first position in which the switch contacts are opened, and second position in which the switch contacts are closed; means defining a slot opening through the housing means for insertion of a key to operate the actuator; blocking means within the housing means; a blocking element; means on said actuator mounting said blocking element for pivotal movement with the actuator and for movement with respect to the actuator, in a direction generally radially of the direction of pivotal movement of the actuator; said blocking element being moveable in said radial direction to a blocking position in which the blocking element cooperates with the blocking means in the housing to prevent pivotal movement of the actuator, and; a released position in which the actuator can be moved from one of its positions to another; spring means for urging said blocking element toward its blocking position; said blocking element having surface means positioned for engagement at two locations by a key inserted through said slot for moving said blocking element to said released position; and means on said actuator for connecting a key inserted through the slot to the actuator for movement therewith to pivot the actuator and switch the switch contacts.