| 摘要 |
<p>A filter assembly incorporates a system for jacking a fitter canister (13) into and out of engagement with a filter head (11). A threaded jackscrew (15) is mated to a threaded portion of the filter head and rotatably mounted on the filter canister, but longitudinally confined near the canister top. The assembly can accommodate a second class lever (46) the fulcrum of which lies in a notch or other recess (44) in the filter head. The jackscrew includes a plurality of circumferentially-spaced lugs against which a portion of the lever can act. The manual application of force to the free end (46B) of the lever creates a mechanical advantage of the jackscrew lugs (48) such that a torque sufficient to free and turn the jackscrew can be generated. Repeated pivoting of the lever against successive lugs of the jackscrew in a ratchet-like manner unscrews the jackscrew, and the captive canister, from the filter head.</p> |
