Gripping device

A gripping device for thin flexible sheet material comprising:

• an elongate channel member containing a longitudinal channel of tapered cross-section opening laterally along its narrow side through one side of said member,
• said channel having longitudinal side walls which converge toward the open side of said channel,
• a gripper bar of substantially fixed tapered cross-section within said channel having longitudinal gripping surfaces along its opposite sides facing said channel side walls, respectively,
• at least one of said gripping surfaces being flat and normally paralleling the adjacent channel side wall,
• said gripper bar having a wide side with a lateral dimension exceeding the width of said open channel side and said gripper bar being movable laterally outward toward said open channel side to a gripping position wherein said bar is wedged between said channel side walls and said gripping surfaces of the bar are disposed in sheet gripping relation to said channel side walls, and
• said channel is adapted to receive said sheet material in a manner such that the sheet material extends through said channel and around said gripper bar between the latter and the channel walls, whereby stress in the sheet material draws the gripper bar outwardly to said gripping position to effect gripping of the sheet material between said gripper bar surfaces and said channel side walls.