GB1222510A - Improvements in or relating to acceleration-responsive control devices - Google Patents

Abstract

1,222,510. Inertia switches. DUNLOP CO. Ltd. 24 April, 1968 [25 April, 1967], No 18973/67. Heading F2F. [Also in Division H1] An inertia-type deceleration responsive device e.g. for an anti-skid system comprises a flywheel 11, Fig. 2, mounted in an annular housing 2 on the gear-box output shaft 5. Teeth inside the flywheel mesh with three equally spaced gearwheels 9 driving cylindrical cams 8 having an inclined end surface 21 co-operating with tubular cams 20 to impart axial movement to a switching member 25 when the flywheel overruns the housing. The switch may be a magnetic reed switch, a pneumatic sensing device operating a switch or a light switch (arrangements are exemplified in the Specification). The switch is connected in a brake control circuit to release the brakes. In a modification, Fig. 8 (not shown), the teeth on the flywheel are formed on its outer periphery so that the flywheel lies within the gearwheels. In a second embodiment, Fig. 9 and Fig. 10 (not shown), a pinion 52 is secured to the cam member 57, on which the flywheel 50 is mounted, and meshes with teeth on the inner periphery 53 of an annular disc 54 provided with a series of magnets 56 on its circumference. A reed switch 60 is mounted on a stationary member 61 between magnets 56 and a second set 59 on an annular member 58 rotating with the housing 55. The arrangement of magnets is such that when the flywheel and housing rotate together, the reed switch is maintained open but is closed when the flywheel overruns the housing, as illustrated in Figs. 11, 12 (not shown). In another embodiment the flywheel is mounted on three flanged pulleys, Fig. 6 (not shown). An axially movable annular member (40) equivalent to member 25 in embodiment of Fig. 2, is connected with the flywheel by a thrust friction arrangement (41). In a further embodiment, Fig. 14, an annular flange 80 is mounted in the housing for limited angular movement relative thereto and is additionally connected between the flywheel 76 and housing by buttons 82 of friction material which contact the flywheel at one end and ramp surfaces 84 on the housing such that when the flywheel overruns the flange 80 is rotated with it a short distance. The flange 80 is connected to an axially slidable flange 85 by rods 94, Fig. 16 (not shown), so that on relative angular movement between the two flanges, caused by flywheel overrun, the flange 85 is moved towards the flange 80, causing a magnetic reed switch 90 to be closed.