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US 4,850,630 AGranted
Clamp with movable jaw structure
AssigneeJ.C. Renfroe & Sons, Inc.
InventorWilliam Davies
Life of this patent
Estimating the term…
Abstract
A screw-type clamp for gripping structural members such as steel sheets has the general form of a U-shaped clamp body, a screw threadedly received through a portion of the body and a jaw pivotally mounted to the body opposing the screw such that members may be securely gripped by a gripping surface on the screw and a gripping surface of the jaw. The jaw is mounted with a ball and socket configuration such that the gripping surface on the jaw stays parallel with the surface of the member being gripped. In a second embodiment, a similar jaw is mounted to the screw. The ball in the ball and socket joints contains an annular groove and is held into the socket by a plurality of pins that tangentially engage the annular groove.
Claims40
A lifting clamp for gripping materials comprising:
- a clamp body adapted for connection to a lifting device and having spaced, opposed, first and second body projections defining therebetween a material receiving slot, said first body projection comprising a first material gripping surface and said second body projection comprising a second material gripping surface;
- adjusting means for adjusting the distance between said first and second material gripping surfaces such that a structural member in said slot is urged into a gripping relationship between said gripping surfaces when the distance between said gripping surfaces is reduced to enable the structural member to be lifted by the clamp;
- a jaw having an inner end mounted in said first body projection and an outer end defining said first material gripping surface, said first material gripping surface being engageable with a surface of a member in the slot, said first body projection and the inner end of said jaw defining a close fitting ball and socket connection therebetween to permit pivotal movement of the outer end of said jaw to enable said jaw to move with the member being gripped in said slot when the member swings while being lifted with said first material gripping surface substantially parallel to, and in full gripping engagement with, the surface of the swinging member;
- and
- wherein said jaw has an intermediate portion between said ball and socket connection and said first material gripping surface, and said first body projection defines a bore fixed relative to said first body projection with an outer portion of said bore surrounding and radially spaced from said intermediate jaw portion to permit said pivotal movement of the outer end of said jaw and to limit said pivotal movement by engagement between said intermediate jaw portion and said outer bore portion.
2 more elements
A screw-type lifting clamp for gripping materials comprising:
- a clamp body adapted for connection to a lifting device and having spaced, opposed, first and second body projections defining therebetween a material receiving slot, said first body projection comprising a first material gripping surface and said second body projection comprising a second material gripping surface;
- a screw having a shaft threadedly received through said first body projection for rotation about a horizontal axis, said screw having a first end defining said first material gripping surface and extending into said slot toward said second body projection, said screw being threadedly movable horizontally toward and away from said second body projection;
- a jaw having an inner end mounted in said second body projection and an outer end defining said second material gripping surface so that threaded movement of said screw toward said jaw urges a structural member in said slot into a gripping relationship between the first and second material gripping surfaces to enable the structural member to be lifted by the clamp, said second projection and said inner end of said jaw defining a ball and socket connection therebetween to permit pivotable rotation of the outer end of said jaw to enable said jaw to move with the member being gripped in said slot when the member swings while being lifted with said second material gripping surface substantially parallel to and in full gripping engagement with a surface of the swinging structural member;
- and
- wherein said jaw has an intermediate portion between said ball and socket connection and said first material gripping surface, and said second projection defines a bore fixed relative to said second body projection with an outer of said bore portion surrounding and radially spaced from said intermediate jaw portion to permit said pivotal movement of the outer end of said jaw and to limit said pivotal movement by engagement between said intermediate jaw portion and said outer bore portion.
2 more elements
A lifting clamp for gripping materials comprising:
- a clamp body adapted for connection to a lifting device and having spaced, opposed, first and second body projections defining therebetween a material receiving slot, said first body projection comprising a first material gripping surface and said second body projection comprising a second material gripping surface;
- a gripping cam attached to said first body projection and comprising said first material gripping surface, said first material gripping surface extending into said slot towards said second body projection;
- a jaw having an inner end mounted in said second body projection and an outer end defining said second material gripping surface so that a structural member in said slot may be urged into a gripping relationship between said first and second material gripping surfaces to enable the structural member to be lifted by the clamp, said second body projection and the inner end of said jaw defining a ball and socket connection therebetween to permit pivotable rotation of the outer end of said jaw to enable said jaw to move with the member being gripped in said slot when the member swings while being lifted with said second material gripping surface substantially parallel to and in full gripping engagement with a surface of the swinging member;
- and
- wherein said jaw has an intermediate portion between said ball and socket connection and said first material gripping surface, and said second projection defines a bore fixed relative to said second body projection with an outer of said bore portion surrounding and radially spaced from said intermediate jaw portion to permit said pivotal movement of the outer end of said jaw and to limit said pivotal movement by engagement between said intermediate jaw portion and said outer bore portion.
2 more elements
A lifting clamp for gripping materials comprising:
- a clamp body adapted for connection to a lifting device and having spaced, opposed, first and second body projections defining therebetween a material receiving slot, said first body projection comprising a first material gripping surface and said second body projection comprising a second material gripping surface;
- adjusting means for adjusting the distance between said first and second material gripping surfaces such that a structural member in said slot is urged into a gripping relationship between said gripping surfaces when the distance between said gripping surfaces is reduced to enable the structural member to be lifted by the clamp;
- a jaw having an inner end mounted in said first body projection and an outer end defining said first material gripping surface, said first material gripping surface being engageable with a surface of a member in the slot, said first body projection and the inner end of said jaw defining a close fitting ball and socket connection therebetween to permit pivotal movement of the outer end of said jaw to enable said jaw to move with the member being gripped in said slot when the member swings while being lifted with said first material gripping surface substantially parallel to, and in full gripping engagement with, the surface of the swinging member;
- and
- wherein said jaw has an intermediate portion between said ball and socket connection and said first material gripping surface, and said first body projection defines a bore fixed relative to said first body projection with an outer portion of said bore surrounding and radially spaced from said intermediate jaw portion to permit said pivotal movement of the outer end of said jaw, said first body projection and said jaw defining mutually matching surfaces engageable with each other by elongated mating contact over a substantial length to limit said pivotal movement.
2 more elements
Dependencies are inferred from the claim text.