| 摘要 |
<p>An hydraulic device (10) is used for an exercise machine, having a double-acting hydraulic pump (11), which can be moved in one direction for developing one set of muscles (for example, biceps), and in the other direction for developing another set of muscles (for example, triceps). The invention provides a valve (14) having two portions (17, 18), each with a pressure regulating valve (19) and a non-return valve (20). Oil displaced by operation of the pump (11) in a first direction passes through a first pressure regulating valve (19), and return oil through a second non-return valve (20), and this is reversed when the pump is operated in a second direction. If the pressure regulating valves (19) permit flow rates which differ, they can be made appropriate for movement effected by the different sets of muscles.</p> |
