Abstract: The vertically reciprocal upper blade assembly of a sheet metal squaring shear is activated in a substantially vertical path past a fixed lower blade by means of one or more reciprocal rotary hydraulic actuators. The output drive shaft of the hydraulic actuator(s) is connected to one or more drive straps by an eccentric cam which is keyed to the drive shaft and rotatably received within the straps. The horizontal gap between the upper blade and the lower blade is precisely controlled by suspending the blade supporting gib bracket from pins on the side walls of the apparatus housing and adjustably connecting the gib plate to the pins by eccentric cams. The gib mounting system also provides for adjusting the angle of the upper blade with respect to the lower blade. An improved hold down assembly limits the stroke of the hold down pins to maintain a slight clearance between the hold down pins and the bed surface at all times.

Abstract: Apparatus is provided for supporting the end portion of a workpiece blank which extends through and to the rear of power shear blades. The apparatus includes a table top and a frame supporting the table top. The front portion of the table top is supported for limited vertical displacement by rollers on opposite sides of the table engaged in horizontal track sections of vertically displaceable tracks interposed between the table top and the frame. The rear portion of the table top is separately supported by reciprocating rear table supports on opposite sides of the table top, the rear table supports being guided for vertical displacement in vertical ways provided on opposite sides of the frame. The table top is displaceable downwardly in response to downward movement of the movable shear blade, and is tiltable rearwardly after initial downward displacement by reason of the rear table supports being allowed greater downward displacement than the rollers supporting the front portion of the table top.