| 摘要 |
<p>A valve for rotation of an intermediate pressure level in a hydraulic brake system is built initially with the spring loaded non-return valve supported clear of its seat by a spacer which is sensitive to and weakened by the brake fluid to be used. The spacer allows the system to be evacuated prior to the initial priming of the system with fluid, in accordance with modern assembly methods, without the valve acting to isolate part of the system while the pressure is below its normal operating condition. The spacer may be a hollow body or a cage made pref. of a polysulphone or a polymethacrylate material, to be weakened sufficiently by the fluid to release the valve core mechanically, or may be a soluble adhesive used to retain the valve core in an 'open' position until after a period of immersion in brake fluid.</p> |
