| 摘要 |
<p>A fluid-pressure-operable device 1 includes two relatively-movable components 2, 3 defining a variable-volume working chamber 9. A sealing element 5 of elastomeric material is carried, or formed, by one of the components and is in sliding and sealing engagement with the other of the components normally to resist escape of fluid under pressure from chamber 9 to the exterior thereof. That face 15 of element 5 remote from the chamber is so provided with channel 16 that as pressure in the chamber increases the element is permitted progressively to deform and some of the material of the element thus displaced is then accommodated by the channel. When the pressure exceeds a predetermined value, deformation of the element is such that sealing engagement of the element with the other of said components is broken so that the pressure in chamber 9 is relieved to the exterior thereof.</p> |
