ANTITHEFT SIGNALLING ACTUATION DEVICE Russian patent published in 1998 - IPC

FIELD: transport engineering; antitheft devices. SUBSTANCE: one or several are installed equidistantly over circumference of wheel brake drum. and magnetically sensitive element - hermetically sealed reed relay is mounted on wheel support disk. Device operates when wheel starts turning and magnet secured on rotating part of wheel, approaches hermetically sealed reed relay mounted on fixed part of wheel. To realize the protection when drum is removed, device is provided with additional hermetically sealed reed relays located within the sector whose angular size is $$$ where Q is maximum angular size of sector between two adjacent magnets. q is angular size of sector of effective action of magnet magnetic field onto hermetically sealed relay. Total number of hermetically sealed reed relays is chosen to provide angular distance between hermetically sealed reed relays not exceeding q. To increase service life of hermetically sealed reed relays, magnet attachment device is made for radial displacement of magnets under action of centrifugal force arising when wheel rotates with vehicle driving and returning them in initial position when vehicle is parked. EFFECT: improved protection. 5 cl, 3 dwg