| 摘要 |
<p>FLUID OPERATED HYDRAULIC PUMP INCLUDING AN IMPROVED HYDRAULIC FLUID PRESSURE RELEASE ASSEMBLY A fluid operated hydraulic pump of the type using air pressure to produce high pressure hydraulic fluid whereby hydraulic fluid can be conveyed to a hydraulic tool or the like, and wherein the hydraulic pump includes an easily actuated release valve to facilitate return of high pressure hydraulic fluid from the hydraulic tool to the fluid reservoir of the hydraulic pump and including a treadle having a curvilinear cam surface for engaging the release valve to actuate it. The hydraulic pump also includes a continuously open hydraulic fluid pressure passage connected to the high pressure output passage of the hydraulic pump and in communication with the release valve bore to facilitate fluid pressure on a shoulder of the release valve thereby maintaining a balance of fluid pressure force on the release valve and facilitating axial movement of the valve with application of only a small axial force.</p> |
