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US 8,069,954 B2Granted
Self erecting zipper lift
AssigneeProduction Resource Group, LLC
InventorJames Kempf
Life of this patent
Estimating the term…
Abstract
A zipper style lift that coils into a box for storage, but extends to form a rigid, self erecting lift part. The lift stores itself in a housing when retracted, by retracting chain parts into a spiral form.
Claims18
A lift comprising:
- a first chain, formed of first links with a first surface, and a second surface, said second surface facing oppositely said first surface, said first links that pivot relative to one another, said first links have first interlocking surfaces on said first surface, wherein said first interlocking surfaces have curved surface portions, and have third interlocking surfaces on said second surface opposite said first surface, wherein said third interlocking surfaces have a curved surface portion, and said second surface is symmetrical to said first surface;
- a second chain, formed of second links with a first surface, and a second surface, said second surface facing oppositely said first surface, said first links that pivot relative to one another and have second interlocking surfaces thereon on said first surface, where said second interlocking surfaces have a curved surface portion, and have fourth interlocking surfaces on said second surface opposite said first surface, wherein said fourth interlocking surfaces have a curved surface portion, and said second surface is symmetrical to said first surface,
- and where curved surfaces of said second links mate to concave portions of said first interlocking surfaces of said first links on both first and second surfaces of said first links, and when mated, hold said first chain to extend in a straight line, and hold said second chain to extend in said straight line interlocked to said first chain, and when mated, prevent said first and second links from pivoting relative to one another;
- a housing, holding said first and second chains;
- a moving part, coupled to said housing, to extend and retract said first and second chains,
- said first and second chains forming a lift that extends above said housing when extended,
- wherein said first and second links include a first portion that includes said interlocking surfaces, a first pivot on a side of said first surface, a first leg, attached to said first pivot and said first portion, a second pivot on side of the second surface, a second leg, attached between said second pivot and said first portion, and said first and second legs having surfaces facing one another which define an open area between said first and second legs, and wherein said open area between said first and second legs is substantially polygonal in shape.
4 more elements
A lift comprising:
- first and second chains that pivot relative to one another when separated, and extend in a straight line when coupled to one another;
- a housing, holding said first and second chains in a retracted position, and supporting a lift part formed from said first and second chains in an extended position, said housing including first surfaces therein which guide portions of said chains to be stored and second surfaces which guide portions of said chains to be coupled, wherein said first and said second chains are each formed of links that include a first portion that includes interlocking surfaces, a first pivot on a side of said first surface, a first leg, attached to said first pivot and said first portion, a second pivot on side of the second surface, a second leg, attached between said second pivot and said first portion, and said first and second legs having surfaces facing one another which define an open area between said first and second legs, where said open area defines an area with no chain material therein, wherein said links of said chains pivot relative to one another, and are separated from each other by a distance along a direction of said chains which is at least as wide as a distance between said pivots, wherein said first and second links include a first portion that includes said interlocking surfaces, a first pivot on a side of said first surface, a first leg, attached to said first pivot and said first portion, a second pivot on side of the second surface, a second leg, attached between said second pivot and said first portion, and wherein said open area between said first and second legs is substantially polygonal in shape.
A method comprising:
- allowing first and second chains to pivot relative to one another on a pivot when separated,
- moving said first and second chains to one another in a way that causes said first and second chains to extend in a straight line, wherein said moving comprises connecting an interlocking surface on a first of said chains which has both concave and convex curved surfaces to an interlocking surface on a second of said chains which also has concave and convex surfaces, and where the convex surfaces on said second chain are connected to the corresponding concave surfaces on the first chain, said moving comprising using a sprocket which connects only to a portion of said chain adjacent to said pivot, and which defines an open space between portions of said sprocket where said open space does not include material that couples against said chain, said open space formed between two adjacent sprocket portions, said sprocket having a central portion, and said moving also comprising applying a rotating force to said central sprocket portion;
- holding said first and second chains in a retracted position in a housing separated from one another;
- and
- supporting an extended lift part formed from said first and second chains in an extended position above the ground, using said housing for the support, wherein said first and second links include a first portion that includes said interlocking surfaces, a first pivot on a side of said first surface, a first leg, attached to said first pivot and said first portion, a second pivot on side of the second surface, a second leg, attached between said second pivot and said first portion, and said first and second legs having surfaces facing one another which define an open area between said first and second legs, and , wherein said open area between said first and second legs is substantially polygonal in shape.
2 more elements
Dependencies are inferred from the claim text.