| 摘要 |
A metal shear includes a shearing blade which moves from a raised position to a lowered position to shear a workpiece. An actuating mechanism includes a lever pivotably mounted on the frame and a linkage connecting the lever to the shearing blade to move the latter between the raised and lowered position in response to pivoting of the lever. A return spring bears against the linkage and yieldably the urges the shearing blade into the raised position. A pneumatic cylinder is mounted on the frame and has an output rod connected to the lever and responds to pressure to pivot the lever to thereby move the shearing blade in opposition to the spring to effect cutting of the workpiece. A control valve is operable to admit air pressure into the actuator to effect operation of the shear, and releases to exhaust air pressure from the cylinder to permit the spring to return the shearing blade to the upper position.
|
