Stretching device

摘要

A stretching device has a housing; a first clamping member attached to a first portion of the housing; a second clamping member attached to a second portion of the housing; wherein the first clamping member has a movable pivot member such that an angle of contact between the first clamping member and a workpiece to be gripped remains constant regardless of the workpiece's thickness. A stretcher assembly has a first stretcher having a first housing having a first clamping member and a second clamping member opposed to each other; and a second stretcher having a second housing having a third clamping member and a fourth clamping member opposed to each other; and a workpiece support member interposed between the first stretcher and the second stretcher, wherein the first and third clamping members each includes a movable pivot joint such that an angle of contact of the first and third members with a workpiece to be gripped remains constant regardless of a thickness of the workpiece. The gripping force remains proportional to a stretching force.

主权项

1. A stretching device comprising: a housing; a first clamping member attached to a first portion of said housing; a second clamping member attached to a second portion of said housing; wherein said first clamping member comprises a plurality of jaws each positioned adjacent and parallel to each other; wherein each of said jaws comprises: a cam profile forming a gripping angle between said each of said jaws and a workpiece to be gripped, and a pivot end which is moved up or down by hydraulic cylinders such that said gripping angle remains the same for various thicknesses of the workpiece, wherein gripping angle results in a gripping force on the workpiece being proportional to a stretching force wherein a ratio of said gripping force to said stretching force remains the same regardless of the thickness of the workpiece.