| 摘要 |
An improved open end wrench having wrench heads at both ends of a shank whereon both wrench heads have arcuate surfaces and backup jaws coplanar with a common torqueing jaw whereby the torqueing jaw is a machined surface of the wrench shank that extends into the wrench heads and is terminated at reliefs at a depth less than half the thickness of the shank, at the intersection of the arcuate surfaces and said torqueing jaw, therein, when excessive torque is applied the relief tends to close whereby the backup jaw and torqueing jaw become nonplanar to each other, therefore wedging the polygonal fastener being worked.
|
