Patent ID: 6374710
Filing Date: 2002-04-23
Classification: B25B

Abstract:
A universal cavity pit wrench adapted for a pitted nut, the universal cavity pit wrench comprising:a sleeve; a mounting panel; a plurality of pillar posts; a plurality of retainer rods and corresponding retraction springs; the sleeve comprising a hollow-set body with an inner wall and an open end, the sleeve configured to accommodate a coupling with a grip, the sleeve having an annular groove built on the inner wall of the hollow-set body; the mounting panel having a lower side, the mounting panel comprising a sheet profiled to match the annular groove on the inner wall of the hollow-set body of the sleeve, the mounting panel secured on the annular groove, the mounting panel including evenly and densely distributed plurality of penetration holes; the plurality of pillar posts extending out of the open end of the body of the sleeve, each of the pillars comprising strap plunger stems having an access hole provided on a tail edge thereof; the plurality of retainer rods each comprising a thin rod having a protrusion on an end thereof, the retainer rods piercing through the mounting panel from the lower side of the mounting panel; a plurality of retraction springs placed on a respective one of the retainer rods and compressible between the mounting panel and the pillar posts always remain extended out of the open end of the body; the retainer rods are inserted into the respective insertion holes on the tail edge of corresponding pillar posts to form compact couplings therebetween; the pillar posts are thrust by the retraction spring out of the open end of the body of the sleeve while retained by the retainer rods at the mounting panel, such that the pillar posts may project fully into a nut bearing cavity pit of a pitted nut, without regard to the pattern of the pitted nut in order to facilitate loosening or tightening up of a pitted nut having a nut bearing cavity pit, upon the rotation of the wrench.