| 摘要 |
In accordance with the present invention, there is provided a filter assembly having an improved system for selectively jacking a filter canister into and out of engagement with a filter head. A threaded jackscrew is mated to a threaded portion of the filter head and rotatably mounted to the filter canister, but longitudinally confined near the canister top. The assembly accommodates a second class lever whose fulcrum end is received in a recess in the filter head. The jackscrew includes a plurality of circumferentially spaced lugs around the jackscrew perimeter against which the central portion of the lever can successively act. The manual application of force to the free end of the lever creates a mechanical advantage at the jackscrew lugs such that a torque sufficient to free and turn the jackscrew can be generated. Repeated pivoting of the lever against the lugs of the jackscrew in a ratchet-like manner unscrews the jackscrew, and the captive canister, from the filter head. |
