| 摘要 |
<p>1,204,739. Hydraulic brakes; valves. BENDIX CORP. 6 June, 1968 [6 June, 1967], No. 26960/68. Headings F2F and F2V. A master cylinder fluid reservoir sealing means for location between an inner chamber 16, 18 of a fluid reservoir and a cover plate 22 to prevent contamination of the fluid in the reservoir, the sealing means comprises a sealing diaphragm 24 operatively secured to the fluid reservoir for sealing the inner chamber 16, 18 thereof and a vent valve 98 is provided in the sealing diaphragm which is operative to prevent pressure build-up in the reservoir chamber. The vent valve 98 is in the form of a check valve having a tubular body portion 104 integral with an annular umbrella portion 102 which is adapted to co-operate with a disc-shaped portion 90 of the sealing member 24 such that, when the vent valve 98 is assembled in a cupshaped portion 94 of the diaphragm 24, the umbrella portion 102 is deformed so that the rim 110 is biased against the upper surface of the cup-shaped portion thereby requiring a certain pressure differential across the umbrella portion before the venting of the chambers 16 or 18 can be caused by excess pressures therein. In the tandem master cylinder arrangement shown in Fig. 1 when the brake pedal is depressed a push rod 66 is moved to the left to urge plungers 38 and 40 to close off the compensating ports 30 and 32 to deliver pressurized fluid at the discharged outlet 72 and 74 of the master cylinder leading to the wheel brake cylinders. Upon release of the brake pedal, the plungers 38 and 40 are returned by the spring 58 and the cage spring 46 to the position shown in Fig. 1 should a residual pressure remain in the braking system which will, in turn, pressurize the chambers 16 and 18 of the reservoir 12 and the excess pressure will be directed to the underside of the vent valve 98 to raise the rim 110 of the umbrella portion 102 to allow the excess gaseous or hydraulic pressure to escape through the serrations 84 between the base portion 76 of the cover 22 and the main base portion 88 of the sealing member 24. The cover member 22 is adapted to be secured in position by means of a spring clip 26.</p> |
