| 摘要 |
<p>1,160,687. Hydraulic brakes; valves. ERNST HEINKEL A.G. 24 Nov., 1966, [7 Dec., 1965], No. 52622/66. Heading F2F and F2V. In an arrangement for bleeding gases (e.g. air) from hydraulic braking systems, a valve housing 3 is provided with a passage 33 through which an hydraulic fluid can flow in both directions, a cylinder 2 and piston 20 unit (e.g. a brake master cylinder 1) is connected with the housing for conveying the fluid through the passage in one direction via the channel 19, a check valve member 8 being provided in the passage which includes an apertured valve seat 6 and resilient means for biasing the valve member into sealing engagement with the seat to prevent flow of fluid in the other direction, valve actuating means, in the form of a screwed plug 12, being operative to move the valve member away from the seat and thus to equalize the fluid pressure at both sides of the seat. In operation, when the hydraulic braking system is in actual use, the screw plug 12 is screwed into the housing 3 and the pin 14 maintains the valve member 8 in an open position so that the pressure in the chamber 2 of the master cylinder 1 equals the pressure in the conduit 32 leading to the wheel brake cylinder 30. In order to expel air bubbles from the hydraulic circuit, the bleeder screws 31 on each wheel brake cylinder 30 are moved to an open position and the end portion 17 of the screw plug 12 is rotated to retract the pin 14 to the position shown in Fig. 2. Repeated pumping of brake fluid from a supply reservoir 22 through the channel 19 causes the fluid to open the check valve 8 by overcoming the bias of the spring 9 and any bubbles of air or other gas which are present in the hydraulic circuit are expelled in response to a few working strokes of the master cylinder piston 20. The bleeder screws 31 are then screwed tight and the screwed plug 12 is returned to its original position to leave the brake system free of gases and ready for renewed use. The check valve 8 is provided with spacer pins 10 which can abut against the end face of the nipple 4 to permit the brake fluid to flow freely between the master cylinder and the wheel brake cylinders during normal brake operation.</p> |
