Patent ID: 7299724

Claim:
A self-adjusting tool with parallel jaws for gripping a workpiece, said tool comprising: a) a first lever having a handle section, an intermediate section, and a first jaw, said first intermediate section having two parallel bearing surfaces and a longitudinally extending slot, said slot having a toothed surface and a smooth surface arranged in opposition to one another, and said first jaw having a first workpiece bearing surface; b) a second lever having a handle section, an intermediate section, and a nose end; c) a second jaw having a second workpiece bearing surface and a nose end receiving slot adapted for receiving said second lever nose end, said nose end receiving slot having a longitudinal axis, said longitudinal axis being disposed at an angle to said smooth surface of said first lever slot, and said second jaw being movably confined by said two parallel bearing surfaces; d) a pawl having a toothed surface and a smooth surface, said pawl being movably situated within said first lever slot; e) a first connection between said pawl and said second lever, said first connection rotatably connecting said pawl and said second lever; f) a third lever having a first and a second end, said first end being operatively connected to said first lever; and g) a second connection operatively connecting said third lever second end to said second lever; wherein when a workpiece is interposed between said first and second jaws and opposing forces are applied to said first lever handle section and said second lever handle section to move them toward one another, said second lever initially rotates about said second connection causing said second jaw to move along said first and second bearing surfaces in the direction of said first jaw until movement of said second jaw is restricted by said workpiece, the movement restriction of said second jaw permitting said opposing forces to cause said second lever nose end to travel within said nose end receiving slot of said second jaw thereby moving said toothed surface of said pawl into locking engagement with said toothed surface of said first lever slot so that further application of said opposing forces causes said second lever to rotate about said first connection and said opposing forces to be transmitted through said first and second workpiece bearing surfaces to said workpiece, said first and second workpiece bearing surfaces being substantially parallel to one another during said transmission of said opposing forces.