| 摘要 |
<p>939,889. Fluid-pressure brakes. KELSEY-HAYES CO. Feb. 19, 1962 [March 3, 1961], No. 6282/62. Class 103 (1). [Also in Group XXIX] Means for reducing hydraulic pressure to the rear wheel brakes of a motor vehicle comprises a valve interposed in the conduit 15 leading from a master cylinder 10 to rear brake cylinders 19, a direct connection 12 leading from the master cylinder to the front brake cylinders 14. The valve is of the inertiaoperated type responsive to deceleration of the vehicle and comprises a steel ball 34 acting as inertia mass and also as a valve to close the entrance 26 to a passage 25 formed in a block 24 of resilient material. The ball is normally held away from the entrance 26 by magnetic force exerted by a magnet 50 mounted in a piston 41 which is held against a shoulder 44 by a spring 49. When pressure is built up in the system fluid passes directly to the front brakes and is initially free to pass to the rear brakes via passage 25 and conduit 17. When the resulting deceleration is sufficient to overcome the magnetic force the ball 34 seats in the entrance 26. Thereafter, increasing pressure in the conduit 15 causes the block 24 to distort progressively, the pressure in conduit 17 being less than the pressure in conduit 15 by an amount corresponding to the resistance of the block to distortion at any given time, until a space 28 is filled with the material of the block, after which no further increase in rear brake pressure can occur. Should brake fade occur or for any other reason a higher braking pressure than -normal occurs before a deceleration sufficient to overcome the force of magnet 50 is produced, piston 41 moves under the higher pressure so that the magnetic force is weakened, thus permitting the ball to move at a lower deceleration to close the entrance 26.</p> |
