Patent CA-2275022-A1 (CA)
Inventor: RADSTROM DONALD M
IPC: G08B13/08
Filed: 1999-06-08
Abstract: In this invention, the central aspect embodies a moveable barrier which may be caused to move into a position such that any other object which normally moves upon, above or within the newly blockaded path or sphere of movement, will be prevented from performing the actions which it was designed to accomplish. The moveable barrier (in all of its various forms, configurations, positioning and means of activating) embodied in the invention is specifically designed to prevent any unauthorized activation or unlocking of so called ' Dead Bolt Locks' by persons exterior to the locked premises who may possess a key capable of such unlocking or activation, or who may have locksmith tools and/or talents to enable the intruder to 'pick' the lock and gain entry.     The dead bolt movement barrier is activated from within the premises to be protected. Some varieties of the barrier device will be connected to a timing device which may allow emergency personel to disengage the barrier - to gain entry in emergency situations.   Enhancing the protective purpose of the moveable barrier is a steel plate of appropriate dimensions which is embedded in the surface of the interior wall segment of the door jamb and the the interior wall immediately adjacent to the dead bolt segment which penetrates into the door jamb when in the locked position. This steel plate extends from several inches above the dead bolt door jamb aperature and extends downward to a point several inches below the door latch aperature. The plate, some 2 inches broad, is fixed to the door jamb and adjoining wall studs and/or 'door frame cripple' by 6 (or more) 2 - 3 inch large gauge screws. Corollaries to the invention's intent to delimit the potential for unwanted/illegal entry into locked/secured premises, are the insertion of 'pin' switches into the existing door jamb aperatures which receive the dead bolt piston and door latch. The pin switches are of the normally closed (N. C.) designation. The electrical contacts of the pin switches are depressed and the switch is open when the door is closed with the dead bolt in the locked position. The pin switches may penetrate the door jamb and the adjoining door rough-opening cripple and adjacent wall stud. Connecting wires join the pin switch contacts to alarms (outside and inside) and one siren through a control panel which houses 2 switches, 2 lights and 1 alarm, as well as distinctive wiring circuitry for power distribution. A one quarter inch movement of the dead bolt piston or door latch will activate respectively a siren or 2 alarms. The system is powered by a 12 volt battery emplaced within the wall adjacent to the door jamb. The battery is continuously recharged by a 12 volt AC/DC adaptor - a precaution against local power outages.  Variations of the door switches may allow for the insertion of other normally closed (N. C.) switches into the door jamb aperatures for door latch and dead bolt penetration such as: limit switches, magnetic switches, mercury switches, radiant energy switches etcetera. These tatter may allow electrical contact with the control panel and alarm systems without drilling into or through the door frame cripple and adjoining wall stud.    To prevent the physical enlargement of a door opening by means of spreading the door jamb members with a jack, a device is provided for insertions within the wall. Two 'feet' joined by a turnbuckle may be placed between the door opening members and the next-in-line wall stud Another corollary to this invention, which involves a design option of the steel plate mentioned above, is a door mounted 'Chain-spool Box' which serves as a securing point and guide for a chain which is anchored at the two points provided (of varied design) on the steel plate. This corollary will replace standard chain guards that only allow the door to open a short distance before the chain impedes further movement in the opening direction.