Plug-type switch

A normally closed alarm switch device for use in supervision whether a movable object remains in a normal fixed position, comprising

• a plug assembly including
• a first multi-contact electrical connector,
• means to electrically short contacts thereof, and
• means to physically secure the first connector to such a movable object, the alarm switch device further comprising
• a receptacle assembly including
• a second multi-contact female electrical connector matable with the first electrical connector and having hook-up terminals associated with the said second connector contacts, and
• an enclosure of such interior dimensions as to contain the second connector with freedom for its movement therein, the enclosure having
• an access opening to its interior,
• a cover for the opening,
• means to lock the cover in place at the opening, and
• passage means into the enclosure of such size that the first connector may be mated from outside the enclosure with the second connector within the enclosure through the passage means and thus to form a closed switch circuit between the second connector hook-up terminals,
• whereby movement of the object from its normal fixed position unmates the connectors, opening the switch circuit, and the connectors may thereafter be remated only by unlocking and removing the enclosure cover and manually positioning and holding the second connector in place.

A normally closed alarm switch device for use in supervision, by an alarm system, of the tetherable manual actuators of water valves and the like, comprising

• A. a plug assembly including
• a male electrical plug of the type having at least two contacts, and
• a loop of flexible insulated conductor by which such manual actuator is tethered and which electrically connects two contacts of the male plug, and
• B. a receptacle assembly including
• (1) an enclosure having an access opening to its interior,
• a cover for the opening,
• means to lock the cover in place at the opening, and
• passage means into the enclosure to accept insertion therethrough of the male plug contacts, the receptacle assembly further including
• (2) a female electrical receptacle contained and movable within the enclosure and of the type having at least two contacts matable through the enclosure passage means with the male plug contacts, and
• (3) a normally closed tamper switch in series with the female receptacle to form a switch circuit and so mounted as to open upon removal of the enclosure cover,
• whereby to signal an alarm upon removal of the enclosure cover, unmating of the plug from the receptacle, or cutting of the loop of conductor.