| 摘要 |
A shearing machine includes a sickle shaped upper jaw interacting scissors fashion with a generally linear lower jaw. The distal ends of the sickle shape begin shearing from opposite ends of a plate-type object at about the same time, with shearing progressing toward a central point. A transverse member and a return leg form, with the lower jaw, a J-shaped device. The upper jaw slides within the return of the J during the entire cutting operation, thereby overcoming any tendency for jaw spreading between the linear and sickle shaped cutters. A front cutting insert in the transverse member and a return cutting insert in the return leg, interact with a tip of the upper jaw to pierce, and then cut, a plate which is longer than the throat of the shearing machine, thereby enabling shearing of large plates. The initial piercing takes place simultaneously at the tip of the upper jaw and at an upward-directed point on the front cutting insert. This two-point contact stabilizes the plate during the initial stages of cutting. A pick-up tooth along the front of the lower jaw enhances the ability to engage a cylindrical object, and move it into position between the linear and sickle shaped cutters. The sickle shaped urges the cylindrical object into a central position, thereby reducing the force required for cutting. Blades are segmented and symmetrical about at least one axis to permit bringing a plurality of edges into effective cutting positions.
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