Claims
- 1. A reversibly expandable loop assembly comprising:a plurality of links having a polygonal profile with three or more corners, a center pivot joint and a plurality of corner pivot joints, each of at least two of said plurality of corner pivot joints proximate to at least two of said three or more corners, respectively, said plurality of corner pivot joints comprising at least one internal corner pivot joint and at least one perimeter corner pivot joint proximately located to the outer edge of said loop assembly; each of said plurality of links connected to another one of said plurality of links at said center pivot joint thereby forming a link pair, said loop assembly comprising at least three link pairs; each of said at least three link pairs connected to at least two other link pairs, through at least one of said internal corner pivot joints; wherein said loop assembly has a unique polygon perimeter outline comprising a ring of line-segments, each line segment comprised of a line which intersects two perimeter corner joints of one of said link pairs, said line segments being equivalent in number to the number of link pairs in said loop assembly; and wherein the angle formed between any two line-segments corresponding to a particular two link pairs in a given position of the loop assembly, is the same as the similarly formed angle between the line segments corresponding to the same two link pairs for any other position of the loop assembly, whereby the size of the ring of line-segments increases with expansion of said loop assembly and decreases with retraction of said loop assembly.
- 2. A loop assembly according to claim 1, wherein said connection between adjacent link-pairs are direct pivot connections between said internal corner pivot joints of said adjacent link-pairs.
- 3. A loop assembly according to claim 1, further comprising one or more hub elements for connecting said internal corner pivot joints of said adjacent link pairs thereto.
- 4. A structure reversibly expandable from a folded to an unfolded position with partially unfolded positions therebetween, comprising at least two loop assemblies in accordance with claim 1, interconnected by said perimeter corner pivot joints.
- 5. A structure according to claim 1, further comprising one or more link pairs having at least one perimeter pivot joint, connected by said perimeter pivot joint to said loop assembly.
- 6. A structure according to claim 4 having a three dimensional shape.
- 7. A structure according to claim 6, further comprising a plurality of loop assemblies connected together by the corner joints of said links of said loop assemblies, wherein at least one of said connection of said plurality of loop assemblies joins together three or more of said links, to form a reversibly expandable three-dimensional matrix of links.
- 8. A reversibly expandable three dimensional structure according to claim 6, wherein at least one of said loop assemblies in accordance with claim 1 comprise at least two link pairs lying in different planes and wherein the angle formed between any two planes of any two link pairs of said loop assembly is substantially constant in any position of said structure.
- 9. A loop assembly in accordance to claim 1, further comprising at least one sheet of material, said material comprising a plurality of stiff regions forming the links of the loop assembly and thin flexible regions forming corner pivot joints of said loop assembly and said stiff regions connected together by one or more of said thin flexible regions.
- 10. A loop assembly according to claim 9, further comprising two sheets of material, said two sheets of material joined together by a plurality of center pivot joint connections.
- 11. A loop assembly in accordance with claim 10, wherein said center pivot joints are living hinges.
- 12. A toy construction kit for building one or more reversibly expandable structures comprising a plurality of loop assemblies in accordance to claim 1, said loop assemblies including perimeter corner joints for connecting any two of said plurality of loop assemblies, whereby said plurality of loop assemblies may be assembled together in various combinations forming reversibly expandable structures of various shapes.
- 13. A toy construction kit for building one or more reversibly expandable structures comprising a plurality of links for assembly into link pairs, each of said links having a polygonal profile with three or more corners, a center joint and at least one corner pivot joint proximate to at least one of said corners for pivotally connecting two adjacent links.
- 14. A toy construction kit according to claim 13, further comprising one or more hub elements, each of said hub elements to be shared by two or more of said links as a pivotal connection therebetween.
- 15. A toy construction kit according to claim 13, further comprising at least two links having at least three corner pivot joints.
- 16. A reversibly expandable loop assembly comprising:a plurality of links having a polygonal profile with three or more corners, a center pivot joint and a plurality of corner pivot joints, each of at least two of said plurality of corner pivot joints proximate to at least two of said three or more corners, respectively, said plurality of corner pivot joints comprising at least one internal corner pivot joint and at least one perimeter corner pivot joint proximately located to the outer edge of said loop assembly; each of said plurality of links connected to another one of said plurality of links at said center pivot joint thereby forming a link pair, said loop assembly comprising at least three link pairs: each of said at least three link pairs connected to at least two link pairs, each of said two link pairs connected through at least one of said internal corner pivot joints of a link in each of said two link pairs, said perimeter corner pivot joint comprising a ball and socket arrangement.
- 17. A loop assembly according to claim 1, which further comprises an additional loop of connecting links, said connecting links each having an elongated profile, and each having one center joint and two terminal joints, wherein:each terminal joint of each connecting link is pivotally connected to an adjacent connecting link, thereby forming a loop; and each center joint of each connecting link is pivotally connected to a polygon link in the loop assembly.
- 18. A reversibly expandable loop assembly comprising:a plurality of links having a polygonal profile with three or more corners, a center pivot joint and a plurality of corner pivot joints, each of at least two of said plurality of corner pivot joints proximate to at least two of said three or more corners, respectively, said plurality of corner pivot joints comprising at least one internal corner pivot joint and at least one perimeter corner pivot joint proximately located to the outer edge of said loop assembly; each of said plurality of links connected to another one of said plurality of links at said center pivot joint thereby forming a link pair, said loop assembly comprising at least three link pairs; and each of said at least three link pairs connected to at least two other link pairs, through at least one of said internal corner pivot joints.
- 19. A loop assembly according to claim 2, wherein each of said perimeter corner pivots has itself a pivotal connection to its corresponding polygon link pair, the axis of said pivotal connection lying essentially within the plane of said polygon link pair.
- 20. A loop assembly according to claim 19, wherein each perimeter corner pivot has one or more flexible regions such that said flexible region of said corner pivot shall flexibly deform when brought together with the flexible region of a corner pivot belonging to another loop assembly, said flexible regions then snapping back to an unstrained condition as the two corner pivots are brought into alignment, thus forming a pivotal attachment between said two perimeter corner pivots, thereby forming a hub element that acts essentially as a ball joint having three intersecting axes of rotation.
- 21. A toy construction kit for building reversibly expanding structures according to claim 12, comprising a plurality of loop assemblies according to claim 20.
- 22. A toy construction kit for building reversibly expandable structures according to claim 12, further including at least one scissor-pair, said scissor pair comprised of two links pivotally connected together at a center pivot joint, two ends of each of said two links each having a terminal pivot point that has itself a pivotal connection to its corresponding link, the axis of said pivotal connection lying essentially within the plane formed by said scissor pair.
- 23. A toy construction kit for building reversibly expandable structures according to claim 12, further including means to attach two loop assemblies together in a stacked arrangement.
- 24. A toy construction kit for building reversibly expandable structures according to claim 12, further including separate hub elements that may be attached to points on loop assemblies to provide extra attachment points.
RELATED APPLICATIONS
This is a continuation-in-part of U.S. patent application Ser. No. 09/154,482, filed Sep. 16, 1998, now U.S Pat. No. 6,082,056.
US Referenced Citations (4)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
09/154482 |
Sep 1998 |
US |
Child |
09/360957 |
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US |