ANTITHEFT ALARM SYSTEM Russian patent published in 2001 - IPC

FIELD: transport engineering; antitheft systems. SUBSTANCE: invention relates to antitheft devices for vehicles powered by internal combustion engines. Said device has safety valve which can adjust pressure of engine exhaust gases depending on power output of vehicle internal combustion engine. Housing is installed in engine exhaust manifold gas receiver. Shutter is made in the form of set of parallel alternating fixed and movable disc plates. Number of movable plates in set is less by one than that of fixed plates. All plates are provided with identical holes for complete relative overlapping when shutter is in closed position. The first movable plate in direction of exhaust gas flow is provided with surface channel to place hole in the first plate into communication with channel in housing connected with alarm device when shutter is closed. Drive and shutoff-and-locking device are arranged in protective housing located on bottom of vehicle is zone of arrangement of driver's seat. Drive of shutter is coupled through shuttoff-and-locking device which precludes unauthorized control and provides operative setting of antitheft device in use from driver's place by command of driver. EFFECT: improved reliability in operation and provision of reliable sound alarm. 5 dwg