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USPTO's for finding information on machinery patents.
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870,781
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Nov. 12, 1907
|
Pipe-Wrench
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George Heckling |
Cleveland, OH |
The roller gripping jaw is held in engagement by a compression spring, and by the interlock formed by the gear teeth on the roller engaged with rack teeth on the shank, and the gripping knurl engaging the item to be grasped. "Forward" motion tightens the grip, "backward" motion relaxes it. (Compare patent no. 710,179).
Production by the Pittsburgh Malleable Iron Company after the mid-1920s probably includes alterations reflected in patent no. 1,593,588. |