Nesting three dimensional lazy tong structure

Claim 2

A link pair for a lazy tong frame comprising: a pair of similar links having mutually parallel central portions arranged side by side at opposite sides of an intervening plane passing between and parallel to said link portions; a center pivot joining said central link portions on a center pivot axis normal to said intervening plane; each link having relatively short and long arms at opposite sides of said pivot; said short arm of one link and said long arm of the other link extending across said intervening plane, whereby said latter arms crossover one another; said short link arms having end portions in a common plane parallel to and located at one side of said intervening plane, and said long link arms having end portions in a common plane parallel to and located at the opposite side of said intervening plane; said short arm end portions having end pivot means with pivot axes parallel to and equally spaced from said center pivot, and said long arm end portions having end pivot means with pivot axes parallel to and equally spaced from said center pivot, the pivot axes of each link being located in a common longitudinal plane of the respective link; and said links being rotatable about said center pivot to folded positions wherein said pivot axes are located in a common longitudinal plane of said links.

Claim 3

A link pair according to claim 1 wherein: said crossing link arms have surfaces which abut in said folded positions.

Claim 4

A link pair according to claim 2 wherein: said surfaces comprise edge surfaces of said links located in said common planes containing the pivot axes of the respective links.

Claim 5

A lazy tong frame comprising: a number of link pairs each including a pair of similar links having mutually parallel central portions arranged side by side at opposite sides of an intervening plane passing between and parallel to said link portions; a center pivot joining said central link portions on a center pivot axis normal to said intervening plane; each link having relatively short and long arms at opposite sides of its center pivot, and said short arm of one link and said long arm of the other link extending across said intervening plane, whereby said latter arms crossover one another; said short link arms having end portions in a common plane parallel to and located at one side of said intervening plane, and said long link arms having end portions in a common plane parallel to and located at the opposite side of said intervening plane; said link pairs being arranged end to end in lazy tong fashion with their center pivot axes parallel to one another and located in a common plane and with said short arm end portions of each link pair located opposite said long arm end portions of the adjacent link pair; end pivots joining the adjacent link end portions of adjacent link pairs on end pivot axes parallel to said center pivot axes; the corresponding end pivots of each link pair being equally spaced from the center pivot of the respective link pair, and the pivot axes of each link being located in a common longitudinal plane of the respective link; said links diminishing in length in the direction of one end of the frame, whereby said frame is tapered and narrows in the direction of said one end, and the pivotally joined link arms of adjacent link pairs have equal length; and said frame is retractable to a contracted configuration wherein said pivot axes of all said link pairs are located in a common plane.

Claim 6

A lazy tong frame comprising: a number of link pairs each including a pair of similar links having mutually parallel central portions arranged side by side at opposite sides of an intervening plane passing between and parallel to said link portions; a center pivot joining said central link portions on a center pivot axis normal to said intervening plane; each link having relatively short and long arms at opposite sides of its center pivot, and said short arm of one link and said long arm of the other link extending across said intervening plane, whereby said latter arms crossover one another; said short link arms having end portions in a common plane parallel to and located at one side of said intervening plane, and said long link arms having end portions in a common plane parallel to and located at the opposite side of said intervening plane; said link pairs being arranged end to end in lazy tong fashion with their center pivot axes parallel to one another and located in a common plane and with said short arm end portions of each link pair located opposite said long arm end portions of the adjacent link pair; end pivots joining the adjacent link end portions of adjacent link pairs on end pivot axes parallel to said center pivot axes; the corresponding end pivots of each link pair being equally spaced from the center pivot of the respective link pair, and the pivot axes of each link being located in a common longitudinal plane of the respective link; said links diminishing in length in the direction of one end of the frame, whereby said frame is tapered and narrows in the direction of said one end, and the pivotally joined link arms of adjacent link pairs have equal length; and said frame is retractable to a contracted configuration wherein said pivot axes of all said link pairs are located in a common plane.

Claim 7

A lazy tong frame according to claim 4 wherein: said crossing link arms have surfaces which abut in said folded positions.

Claim 8

A lazy tong frame according to claim 5 wherein: said surfaces comprise edge surfaces of said links located in said common planes containing the pivot axes of the respective links.

Claim 9

A nesting three-dimensional lazy tong structure of hollow polygonal cross-section, comprising: a number of lazy tong frame forming the sides, respectively, of structure; each frame comprising a number of link pairs each including a pair of similar links having mutually parallel central portions arranged side by side at opposite sides of an intervening plane passing between and parallel to said link portions; a center pivot joining said central link portions on a center pivot axis normal to said intervening plane; each link having relatively short and long arms at opposite sides of its center pivot, and said short arm of one link and said long arm of the other link extending across said intervening plane, whereby said latter arms crossover one another; said short link arms having end portions in a common plane parallel to and located at one side of said intervening plane, and said long link arms having end portions in a common plane parallel to and located at the opposite side of said intervening plane; said link pairs being arranged end to end in lazy tong fashion with their center pivot axes parallel to one another and located in a common plane and with said short arm end portions of each link pair located opposite said long arm end portions Of the adjacent link pair; end pivots joining the adjacent link end portions of adjacent link pairs on end pivot axes parallel to said center pivot axes; the corresponding end pivots of each link pair being equally spaced from the center pivot of the respective link pair, and the pivot axes of each link being located in a common longitudinal plane of the respective link; said links diminishing in length in the direction of one end of the frame, whereby said frame is tapered and narrows in the direction of said one end, and the pivotally joined link arms of adjacent link pairs have equal length; said frames being arranged edge to edge in a hollow polygonal configuration with the narrow ends of said frames at the same end of said structure; rigid corner brackets joining the adjacent end pivots of adjacent frames; and said structure being retractable to a contracted configuration wherein the tiers of said structure nest one within the other and all the pivot axes of said structure are located in a common plane normal to the longitudinal axis of said structure.

Claim 10

A nesting three-dimensional lazy tong structure of hollow polygonal cross-section, comprising: a number of lazy tong frame forming the sides, respectively, of structure; each frame comprising a number of link pairs each including a pair of similar links having mutually parallel central portions arranged side by side at opposite sides of an intervening plane passing between and parallel to said link portions; a center pivot joining said central link portions on a center pivot axis normal to said intervening plane; each link having relatively short and long arms at opposite sides of its center pivot, and said short arm of one link and said long arm of the other link extending across said intervening plane, whereby said latter arms crossover one another; said short link arms having end portions in a common plane parallel to and located at one side of said intervening plane, and said long link arms having end portions in a common plane parallel to and located at the opposite side of said intervening plane; said link pairs being arranged end to end in lazy tong fashion with their center pivot axes parallel to one another and located in a common plane and with said short arm end portions of each link pair located opposite said long arm end portions Of the adjacent link pair; end pivots joining the adjacent link end portions of adjacent link pairs on end pivot axes parallel to said center pivot axes; the corresponding end pivots of each link pair being equally spaced from the center pivot of the respective link pair, and the pivot axes of each link being located in a common longitudinal plane of the respective link; said links diminishing in length in the direction of one end of the frame, whereby said frame is tapered and narrows in the direction of said one end, and the pivotally joined link arms of adjacent link pairs have equal length; said frames being arranged edge to edge in a hollow polygonal configuration with the narrow ends of said frames at the same end of said structure; rigid corner brackets joining the adjacent end pivots of adjacent frames; and said structure being retractable to a contracted configuration wherein the tiers of said structure nest one within the other and all the pivot axes of said structure are located in a common plane normal to the longitudinal axis of said structure.

Claim 11

A structure according to claim 7 wherein: said structure has a generally triangular cross-section and includes three lazy tong frames.

Claim 12

A structure according to claim 7 wherein: each said frame includes a pair of end links at each frame end equal in length to the adjacent link arms, pivot means joining one end of each pair of end links to the end portions of the adjacent link arms on pivot axes parallel to the remaining frame pivot axes, and pivot means joining the opposite ends of said end links on a pivot axis parallel to the remaining frame pivot axes.

Claim 13

A structure according to claim 9 including: mounting brackets and a support at the wide and narrow ends, respectively, of said frames and pivotally joined to said opposite ends of said end links by the adjacent end link pivots.