| 摘要 |
1,190,573. Anti-skid br@ system for road vehicles. DUNLOP CO. Ltd. 3 July, 1967 [5 July, 1966], No. 30121/66. Heading F2F. In an anti-skid braking system incorporating a skid sensing device arranged to release at least one of a vehicle's brakes to avoid locking, there is provided a sensitivity control valve 12 (Fig. 1) (detailed in Fig. 2) to control air pressure to the brake operating mechanism. The control valve 12 has an inlet port 24 connected to a reservoir 7 (Fig. 1) via a driver's valve 6 and an outlet 23 connected to a chamber 2 of brake operating mechanism 1. A restrictor member 25, movable by a diaphragm actuator 41 when supplied with air under pressure via inlet 13 and non-return valve 47 from a valve 9 when a plunger 10 therein is actuated by an inertia type skid sensor (not shown), provides a variable restriction to the flow of air through passage 22 for operating the brakes. The restrictor has a head 27 for engagement with a valve seat 28 and is provided with a recess 29 which permits only a restricted flow from inlet 24 to outlet 23 when head 27 is seated. The non-return valve 47 has a bleed orifice 50 to permit an exhaust flow of air from chamber 42 at a predetermined rate following each anti-skid operation. Anti-skid operation (Fig. 1).-When a skid is sensed plunger 10 of valve 9 is moved and causes air pressure from a reservoir 8 to be admitted to a chamber 3. Simultaneously air pressure is applied via line 13 to chamber 42 of actuator 41, thereby the restrictor member is moved to restrict flow to chamber 2. When the skid tendency is overcome plunger 10 is released and chamber 3 is connected to exhaust. The rise in pressure in chamber 2 is delayed by the restrictor to ensure that the rise does not occur in a period when anti-skid control valve 9 is operating cyclically to apply and release the brakes. Alternatively, the restrictor valve actuator may include a piston (Fig. 3, not shown) instead of a diaphragm, and a needle valve may be provided by means of which a restricted exhaust flow from the actuator is adjustable, to adjust the period of time in which the restrictor offers the greatest restriction. Specification 1,151,223 is referred to. |
