| 摘要 |
A claw hammer head has a fulcrum member hinged by a hinge assembly to the head for swinging between retracted and extended positions. In the retracted position, the fulcrum member is retained in a recess in the head so that the hammer can be used for driving nails into a work surface in the normal manner. In the extended position, the fulcrum member is swung relative to the head to extend beyond the head so as to increase leverage for extracting nails from the surface. The fulcrum member is hinged to the head in such a manner that load incurred while extracting nails is transferred essentially directly to a bearing surface of the hammer head, and thus relieves load from the hinge assembly. The fulcrum member has a periphery that contacts the work surface in the extended position, the periphery having a relatively large radius of curvature for initially extracting the nail, and then rolls onto a smaller radius of curvature when the nail is partially removed from the surface, thus relieving the work surface of high initial loading, and reducing damage to the surface.
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