| 摘要 |
The present invention relates to a safety valve for use in a system for supplying hydraulic, pneumatic, or any other fluid, cylinders, or generally in systems having any enclosure which includes a pressurised fluid, this safety valve makes it possible to prevent, for example, the hydraulic or pneumatic cylinder from retracting instantaneously when there is a break in the supply pipe. This safety valve prevents the fall, in particular, of the loads lifted by a system with a hydraulic cylinder, or the instantaneous collapsing (retraction) of a skip or loading platform of a truck which has been tilted under the action of this hydraulic cylinder. The safety valve according to the present invention includes a stopper element 30, 30', 30'' which is forced into its open position by a spring 11, 11', 11'', the flow of the fluid in the supply direction as well as the flow of this fluid in the opposite direction at a limited speed being permitted by holding the stopper element in its open position. Excessive speed of flow in the opposite direction produces a dynamic pressure under which the valve is closed, thus preventing the extension of the hydraulic or pneumatic cylinder from retracting under the force of its load following a break in the supply pipe or other elements communicating with this pipe. <IMAGE>
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