GB982782A - Improvements in or relating to frictional rotation transmitting devices - Google Patents

Abstract

982,782. Slip couplings; anti-skid brakes. AUTOMOTIVE PRODUCTS CO. Ltd. Oct. 31, 1963 [Nov. 21, 1962], No. 44053/62. Headings F2F and F2U. A friction slip-coupling 62 between a torquesensing flywheel 58 and sleeve 59 of an antiskid device for a motion-vehicle liquid pressure braking system comprises a pair of annular plates 69, 71 fast at one end of the sleeve 59 and carrying a ring of balls 72 engaging cam ramps 74 of a disc 65, or, alternatively (not shown), a screw-threaded engagement between the sleeve 59 and disc 65, which disc 65 frictionally seats in a recess 66 of the flywheel 58, the disc 65 and plate 69 being connected by a torsion spring 75 tending to rotate the disc 65 in the direction to bias the camming balls 72 to clamp the flywheel 58 frictionally between the disc 65 and a flange 67 on the sleeve 59, the torque capacity, due to the camming effect, being greater in one direction than in the other. The anti-skid sensing device is beltdriven from the vehicle propeller shaft and controls a valve unit 15 which is connected in the liquid line between the rear wheel brake cylinders and a master cylinder and is normally maintained open by a servomotor unit permanently connected at 48 with a vacuum reservoir and having a bleed 51 to maintain an equal vacuum in chambers 38, 39 on either side of a diaphragm 37 so that a spring 46 acting through a cap 45 and plunger 34 holds a ball valve 28 open. The upper chamber 38 is further connected through a conduit 49 to a valve 22 of the anti-skid sensing device. Normally, the flywheel 58 is driven by the slip-coupling 62 in the high torque direction through the sleeve 59 and the balls 72 mounted in cam recesses of a plate 63 connected by a peg 79 to the driven pulley 56, but if, during braking, excessive rear wheel deceleration takes place, the flywheel 58 overruns and turns the sleeve 59 relative to the plate 63 which, through the balls 72, lifts a valve-disc 52, venting the chamber 38 to retract the plunger 34, thereby closing the ball valve 28 to cut-off the master cylinder and increase the volume of the brake supply line to reduce brake pressure therein.