Patent ID: 7454943
Filing Date: 2008-11-25
Classification: B21D

Abstract:
1. A bending die for use in sheet metal forming, comprising: (a) a first movable component including a first working surface, the first movable component and the first working surface extending longitudinally relative to a longitudinal axis of the bending die, the first working surface being generally planar and comprising a first inner edge extending longitudinally relative to the longitudinal axis of the bending die; (b) a second movable component including a second working surface, the second movable component and the second working surface extending longitudinally relative to the longitudinal axis of the bending die and disposed adjacent to said first working surface, the second working surface being generally planar and comprising a second inner edge extending longitudinally relative to the longitudinal axis of the bending die, the first inner edge and the second inner edge being oriented substantially adjacent to one another in a facing relationship; (c) a frame configured to provide support for said first and second movable component, while enabling said first and second working surfaces to move relative to the frame, such that a substantially fixed separation between the first inner edge and the second inner edge is maintained, regardless of a rotational angular displacement of either of the first and second movable components, the frame supporting the first and second movable components, wherein a first sector gear engages a first linear rack gear that is attached to the frame to movably support the first movable component, a second sector gear engages a second linear rack gear that is attached to the frame to movably support the second movable component, the first linear rack gear and the second linear rack gears being oriented parallel to each other, the first sector gear and second sector gear being disposed generally adjacent to one another; and (d) a hinge assembly coupling the first sector gear to the second sector gear, such that a rotational displacement of one of said first and second working surfaces results in a corresponding rotational displacement of the other of said first and second working surfaces, but in an opposite rotational direction, the hinge assembly comprising a first link and a second link joined by a pivot shaft, the first link being coupled to the first sector gear, and the second link being coupled to the second sector gear.