Patent ID: 6959580

Claim:
A sheet metal bending brake comprising: a frame having a planar work support surface and at least two spaced frame members extending above said work support surface, each frame member having a throughbore such that said throughbores in said frame members are aligned with each other, at least two elongated pivot arms, each arm being pivotally secured at one end to said frame for movement toward and away from said work support surface, each pivot arm having a generally rectangular opening aligned with said frame member throughbores, a clamp bar secured to said pivot arms so that said clamp bar overlies said work support surface, a slide block longitudinally slidably mounted in each pivot arm opening, said slide block being constrained against movement in a direction generally perpendicular to said work support surface, wherein each slide block includes a trapezoidal opening with spaced apart and parallel top and bottom surfaces and outwardly flared side surfaces, an elongated shaft rotatably mounted in said frame member throughbores, said shaft extending through said trapezoidal openings, at least two eccentric cams secured to said shaft so that one cam is associated with and positioned within each trapezoidal opening, said cam being dimensioned so that each said cam contacts said outwardly flared side surfaces of its associated slide block, whereby pivotal movement of said shaft displaces said clamp bar in a direction generally perpendicular to said work support surface.