Abstract: A lifting clamp for articles such as steel plates has a clamp body defining a slot to receive the article to be lifted with opposed jaws mounted on opposite sides of the slot, one jaw being mounted for opening and closing movement relative to the other jaw, a shackle mounted for guided movement in the clamp body and adapted for connection to a lifting force, linkage connecting the shackle to the movable jaw and a shiftable locking mechanism engagable with the assembly of the movable jaw and linkage to lock the jaws in either their open or closed positions. The locking mechanism has associated therewith a spring biased locking pin carried by the clamp body for holding the locking mechanism in the closed jaw position and a handle operable from the clamp body exterior to shift such mechanism, such handle carrying a manually engagable push button disposed to be engagable with the locking pin to release the locking mechanism from the closed jaw position.

Abstract: A non-marring lifting clamp for articles such as metal plates has a pair of opposed jaws mounted on opposite sides of a slot formed in the side plates of the clamp body with one of the jaws being pivotally mounted for opening and closing movements relative to the other jaw, and a lifting shackle being mounted for guided movement in the clamp body. A linkage assembly in the body couples the shackle to the pivotally mounted gripping jaw to urge the gripping jaw toward the other jaw when a lifting force is applied to the shackle. The linkage assembly includes a swing link connected to move the gripping jaw and a control link pivoted to the clamp body with a connecting mechanism coupling the control link both to the shackle and to the swing link.

Abstract: A screw-type lifting clamp comprising a generally U-shaped clamp body having a pair of spaced, opposed projections defining a generally vertically downwardly facing material receiving slot, a lifting shackle attached to said clamp body, a screw threadedly received through a first such body projection and being threadedly movable toward and away from the second body projection, a jaw pivotally mounted to the second body projection for pivotable movement about a horizontal axis perpendicular to the screw axis, and resilient means urging the jaw to a horizontal position. The pivotable jaw includes vertically spaced teeth defining a gripping surface which is convex in a vertical plane and has a radius of curvature greater than the horizontal distance between the jaw pivotal axis and the jaw gripping surface when that jaw is horizontal.

Abstract: A lifting clamp for articles such as steel plates has a movable arcuate gripping jaw, a pivotally mounted arcuate cam jaw, an enlarged recessed opening to receive the article to be lifted, a shackle, a linkage connecting the shackle to the gripping jaw and a locking mechanism engageable with the linkage to lock the gripping jaw in either open or closed position. The locking mechanism has a handle located outside of the clamp body, an integral connection between the handle and an interior portion of the locking mechanism and an auxiliary spring biased locking pin for holding the locking mechanism in the closed position.