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US 2006/0137493 A1Published application
Ratchet wrench
OwnerMasakazu Nagatainventor
Life of this patent
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OwnerMasakazu Nagatainventor
Estimating the term…
Provided is a ratchet wrench for greatly decreasing the amount of wear at sliding-contact surfaces between a shank and a member which is in contact with the shank. A shank (32) as a rotating member is brought into contact with a friction member (70) formed of a sintered copper alloy, but is kept out of contact with an annular holding portion (20b). By contact of the shank (32) with the friction member (70) formed of a sintered copper alloy, the amount of wear of a sliding-contact surface of the shank (32) with the friction member (70) and that of a sliding-contact surface of the friction member (70) with the shank (32) become extremely smaller than in the prior art. Consequently, it is possible to prevent a lowering of friction of the shank (32) and perform a tightening or loosening work for bolts, etc. stably over a long period.
A ratchet wrench comprising a housing having a first annular holding portion and a second annular holding portion spaced from each other, a shank having a base portion and an engaging portion and disposed between said first and second annular holding portions, and a spring for imparting friction to said shank and for urging the shank toward said second annular holding portion, wherein a friction member formed of a sintered copper alloy is interposed between said base portion of said shank and said second annular holding portion.
A ratchet wrench comprising a housing having a first annular holding portion and a second annular holding portion spaced from each other, a shank having a base portion and an engaging portion and disposed between said first and second annular holding portions, and a spring for imparting friction to said shank and for urging the shank toward said second annular holding portion, wherein a film of a sintered copper alloy is formed on at least one of a surface of contact of said shank with said second annular holding portion or a surface of contact of said second annular holding portion with said shank.
Dependencies are inferred from the claim text.