| 摘要 |
1,059,180. Brake pressure proportioning valves. KELSEY-HAYES CO. Aug. 5, 1964 [Aug. 16, 1963], No. 31889/64. Heading F2F. The rear brakes of a vehicle are connected to the master cylinder by a device which, after the braking fluid pressure has exceeded a certain value allows the pressure in the rear wheel brake cylinders to rise at a rate lower than the rate of increase in pressure in the front wheel cylinders. The device is connected at 62 to the master-cylinder 10, fluid therefrom passing from chamber 55 through passages 54, 57, 50 to chamber 58 connected to the rear wheel cylinders 15. When the fluid pressure exceeds a predetermined value the hollow piston 25 moves leftwards against the action of springs 42, 45, under the effect of fluid acting in the space 31, to apply its valve face 33 to the valve seat 51 and close communication between chambers 55 and 58. A further rise in pressure in chamber 55 acts on the small area of the valve face 33 to crack the valve to allow a reduced rise in pressure to occur in chamber 58 and act on the larger area of cavity 31 to move the piston 25 in a valve closing direction. When, during brake release, for example, the pressure in chamber 55 falls below that in chamber 58 fluid can flow back to chamber 55 past the lip of the seal 37. |
