Patent ID: 8487726
Filing Date: 2013-07-16
Classification: H01H

Abstract:
1. A tamper-resistant switch assembly operable to detect movement of a metal door relative to a metal door frame, said door frame and door each having elongated, rectangular opening formed in opposed surfaces of the door frame and door, said door frame and door openings being in adjacent, opposed relationship when the door is in a closed position within the door frame, there being a pair of opposed, apertured, inwardly extending connection ears at the ends of each of the door frame and door openings, the door frame and door each having a hollow interior space adjacent the corresponding rectangular opening thereof, said switch assembly comprising: a first movement-sensing switch located within said hollow interior space of said door frame and operable to switch between first and second separate movement-sensing states in response to movement of said door relative to said door frame; a second tamper-sensing switch assembly also located within said hollow interior space of said door frame and including a switchable component and an actuating component, said switchable component and actuating component being relatively shiftable, said switchable component switchable between first and second tamper-sensing states in response to said relative shifting between the switchable and actuating components, said first movement-sensing switch and the switchable component of said second tamper-sensing switch assembly located within a common housing with said movement-sensing switch proximal to the door frame opening, and with said switchable component located at a position remote from said door frame opening, said common housing secured to a first mounting plate covering said door frame opening, said a first mounting plate having a pair of connection openings; an elongated bracket located within said hollow interior space of said door frame in opposition to said anti-tamper mounting plate, said bracket having a first pair of outboard connection openings at opposite ends thereof in alignment with the apertures of said door frame connection ears, said first bracket further including a second pair of inboard connection opening inboard of said first pair of outboard connection openings, a first pair of threaded connectors extending through said first outboard pair of connection openings and through the aligned apertures of the door connection ears, in order to secure said first mounting bracket to said door frame; a second pair of threaded connectors extending through said first mounting plate connection openings and said inboard pair of bracket connection openings, in order to secure the first mounting plate and said supported common housing to said door frame, said actuation component being supported on said bracket and adjacent said switchable component, with said switchable component being separable from said actuating component upon attempted detachment of said bracket from said door frame by removal of said second pair of threaded connectors, said first movement-switch being a magnetically actuatable switch operable to switch between first an second separate movement-sensing states in response to a change in magnetic field conditions adjacent the first movement-sensing switch; and a biasing magnet located within the interior hollow space of said door and supported by an elongated second mounting plate having a pair of connection openings, said second mounting plate covering said door opening, with a third pair of threaded connectors passing through said second mounting plate and into the connection ear openings of the connection ears of said door frame, said biasing magnet operable to maintain said first movement-sensing switch in on of the states thereof when said door is in said closed position thereof within said door frame, said first movement-sensing switch moving to the other switch state thereof when said door is opened, owing to the change of magnetic field conditions adjacent the first movement-sensing switch,