US 6,026,714 AGranted

Adjustable wrench

OwnerJong-Shing Changinventor

Life of this patent

Estimating the term…

Loading patent…

Abstract

An adjustable wrench is composed of a handle and a clamping member fastened pivotally with the handle and provided with two clamping surfaces forming therebetween an angle of 120 degrees. The clamping member is capable of turning on a pivoting point which is located at the center of the pivoting position of a clamped portion of the handle. The pivoting position has a horizontal width which is 3-3.5 times a distance between a longitudinal line of the pivoting point and a longitudinal line passing the curvature center of an arcuate lower clamping surface of the clamped portion of the handle. The arcuate lower clamping surface has a curvature radius which is 2.5-3.5 times a distance between the two longitudinal lines. The arcuate lower clamping surface has an arc line length corresponding in location to a circle center angle ranging between 70 and 90 degrees. When the handle is exerted on by an external force, the workpiece is held securely by a clamping force which is directly proportional in strength to the external force.

Claims9

Dependent claims

An adjustable wrench comprising:

a handle having at an upper end thereof a clamped portion provided with an arcuate lower clamping surface;
a clamping member fastened pivotally with said upper end of said handle and provided with two upper clamping surfaces forming therebetween an angle of 120 degree, said lower clamping surface forming with each of said upper clamping surface a clamping space having an open end;
wherein said clamping member and said upper end of said handle are fastened pivotally at a pivoting point which is located at a center of a transverse width of said clamped portion and on a first longitudinal line substantially parallel to an axis of the handle, said width being 3-3.5 times a transverse distance between said first longitudinal line and a second longitudinal line substantially parallel to the axis of the handle and passing through a center of said arcuate lower clamping surface of said handle, a circular arc of said arcuate lower clamping surface having a radius which is 2.5-3.3 times said transverse distance, said circular arc of said arcuate lower clamping surface having an angle ranging between 70 and 90 degrees.

Dependencies are inferred from the claim text.