FOLDING STRUCTURE
United States Patent 3836418
A plurality of rectangular members interconnected by hinges such that the members in one unfolded configuration form a square having a side length to height ratio of 8:1 and in a second configuration form a cube having an edge length of four units. A flexible cord is provided interconnecting some of the rectangular members such that pulling the central portion of the cord causes the square to fold to the cube form while pulling the opposed ends of the cord causes the cube to unfold to the square form.
US Patent References:
Hinge construction
Grumbacher - July 1964 - 2228110
Block puzzle
Dreyer - December 1965 - 3222072
BODY OF VARIABLE FORM COMPOSED OF A PLURALITY OF HINGEDLY CONNECTED ORTHOGONAL PRISMS NO LESS THAN SIX
Bock-Gressau - December 1970 - 3550310
SYSTEM OF HINGED POLYGONIC SHAPES
Thomson - August 1971 - 3596396
EDUCATIONAL TOY DEVICE
Thompson - December 1971 - 3628261
Hinge construction
Grumbacher - July 1964 - 2228110
Block puzzle
Dreyer - December 1965 - 3222072
BODY OF VARIABLE FORM COMPOSED OF A PLURALITY OF HINGEDLY CONNECTED ORTHOGONAL PRISMS NO LESS THAN SIX
Bock-Gressau - December 1970 - 3550310
SYSTEM OF HINGED POLYGONIC SHAPES
Thomson - August 1971 - 3596396
EDUCATIONAL TOY DEVICE
Thompson - December 1971 - 3628261
Application Number:
05/329077
Publication Date:
09/17/1974
Filing Date:
02/02/1973
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
273/285, 273/155
International Classes:
A63H33/04
Field of Search:
161/17 46/1R,26 35/69,70 16/180
Primary Examiner:
Schulz, William E.
Attorney, Agent or Firm:
Graybeal, Barnard, Uhlir & Hughes
Parent Case Data:
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of my now pending application Ser. No. 73,756, entitled Multi-Fold Structure, filed Sept. 21, 1970 and now abandoned, and the drawings and specification of said application Ser. No. 73,756 are hereby incorporated by reference in this application.
Claims:
What is claimed is
1. A folding structure in the form of a square board one unit thick and eight units long on each side foldable into a cube four units long on each edge, comprising:
2. The folding structure of claim 1 including a pair of holes in said center member and a single hole in each of said first opposite pair of side members; a single cord means extending through said holes and slidably movable therein such that the center portion of said cord forms a loop between said pair of holes in said center member; cord attaching points on a pair of diagonally opposed corner members; the opposed end portions of said cord means extending from said holes in said first opposite pair of side members to said cord attaching points and then outwardly therefrom; and whereby pulling said loop portion of said cord causes said structure to fold to a cube and pulling said opposed ends of said cord causes said cube to unfold to a square.
3. The folding structure of claim 2 wherein said opposed ends of said cord means include hand grip portions.
4. The folding structure of claim 1 wherein said square center member, said side member and said corner members are hollow and include opening means communicating with said hollow interiors.
5. The folding structure of claim 1 wherein said corner members, said side members and said center member are related to each other in size as one is to two is to four.
6. A folding structure comprising a square center member and a surrounding rectangular chain of four alternating side members and four corner members; hinge means interconnecting said alternating side members and corner members such that adjacent members are pivotal with respect to each other, consecutive pairs of hinges being alternately mounted on vertically opposed sides of said adjacent side members and corner members; and, a pair of hinge means extending between said center member and an opposed pair of side members to pivotally interconnect said center member with said surrounding rectangular chain.
1. A folding structure in the form of a square board one unit thick and eight units long on each side foldable into a cube four units long on each edge, comprising:
2. The folding structure of claim 1 including a pair of holes in said center member and a single hole in each of said first opposite pair of side members; a single cord means extending through said holes and slidably movable therein such that the center portion of said cord forms a loop between said pair of holes in said center member; cord attaching points on a pair of diagonally opposed corner members; the opposed end portions of said cord means extending from said holes in said first opposite pair of side members to said cord attaching points and then outwardly therefrom; and whereby pulling said loop portion of said cord causes said structure to fold to a cube and pulling said opposed ends of said cord causes said cube to unfold to a square.
3. The folding structure of claim 2 wherein said opposed ends of said cord means include hand grip portions.
4. The folding structure of claim 1 wherein said square center member, said side member and said corner members are hollow and include opening means communicating with said hollow interiors.
5. The folding structure of claim 1 wherein said corner members, said side members and said center member are related to each other in size as one is to two is to four.
6. A folding structure comprising a square center member and a surrounding rectangular chain of four alternating side members and four corner members; hinge means interconnecting said alternating side members and corner members such that adjacent members are pivotal with respect to each other, consecutive pairs of hinges being alternately mounted on vertically opposed sides of said adjacent side members and corner members; and, a pair of hinge means extending between said center member and an opposed pair of side members to pivotally interconnect said center member with said surrounding rectangular chain.
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, in general, to a uniquely folding structure, and in particular, to a structure comprising a plurality of rectangular members hingedly interconnected to semi-automatically fold from a square to a cube or from a cube to a square in response to manipulation of a single cord running through or connected to selected rectangular members.
2. Description of the Prior Art
The interconnection of cube shaped units by means of cords to form a puzzle or amusement device is known per se. For example, U.S. Pat. Nos. 3,487,578 and 3,222,072 disclose puzzles of this type. Neither of these patents disclose the use of a flexible cord to manipulate the folding of the cubes with respect to each other, but rather the cord merely acts to interconnect the cubes. U.S. Pat. Nos. 3,550,310, 3,596,396 and 3,628,261 disclose other forms of cube puzzles all of which differ substantially from the instant invention with respect to both the shape of the interconnected members, the position of the hinges interconnecting the members, the location and function of the cord running through the members and the novel and intriguing operation thereof whereby the structure may be semi-automatically folded and unfolded between planar square and cube configurations.
Other patents illustrating the scope of the prior art but deemed to be substantially less relevant to the instant invention include U.S. Pat. Nos. 3,201,894; 3,577,673; 2,228,110; 926,365; 2,064,826; 2,334,486; 3,360,806; 3,462,150 and 2,880,001.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a folding structure comprising a plurality of three dimensional rectangular members hingedly interconnected to fold between a square having a thickness of one unit and a side length of eight units and a cube having a side length of four units in response to pulling force applied to either the center or ends of a string interconnecting some of the rectangular members. The invention thus provides unique means for rapidly stacking a plurality of rectangular members in a stable, compact shape for storage.
In one embodiment, the surface decoration of the rectangular members may include alternating light and dark squares such that when the structure is in the planar square form it forms a chess or checker board. Alternately, the rectangular members may be hollow and each include a closable opening whereby they may be used to store a plurality of like items of varying size such as nuts, bolts, washers or the like.
It is an object of the present invention, therefore, to provide a folding structure adapted to be semi-automatically folded between a first planar square form and a second cube form.
Another object of the instant invention is to provide a folding structure having a single flexible cord extending through or interconnected with some of the hingedly interconnected rectangular members whereby a pulling force exerted on the ends of the cord causes the block to unfold from a cube to a square while a pulling force exerted on the center portion of the cord causes the structure to fold from a square to a cube.
Still another object is to provide a game board which may be quickly and easily unfolded for use or folded for storage.
An additional object of the present invention is to provide a folding structure of the disclosed type which may be used as an article of furniture.
One more object of the present invention is to provide a folding structure of the disclosed type which may be used as a storage unit.
One more object is to provide a folding structure formed from a plurality of varying sized rectangular members some of which are interconnected with adjacent members by means of a first set of hinges positioned along parallel lines on a first surface of the planar square form of the structure and a second set of hinges positioned along parallel lines transverse said first parallel lines on the surface of said planar square opposite said first surface.
Other and additional objects and advantages will be apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a typical folding structure made according to the instant invention unfolded to form a planar square. FIG. 2 is a perspective view of the bottom portion of the folding structure of FIG. 1.
FIG. 3 is a perspective view of the folding structure of FIG. 1 wherein some of the members are being partially folded in response to an upward pulling force exerted on the center portion of the flexible cord.
FIG. 4 is a perspective view of the folding structure of FIG. 3 showing the structure after the folding action of FIG. 3 is completed.
FIG. 5 is a perspective view of the foldable structure of FIG. 4 wherein some of the rectangular members are being additionally folded in response to additional upward force on the center portion of the flexible cord.
FIG. 6 is a perspective view of the folding structure of FIG. 5 showing the folding structure completely folded to its cube form.
FIG. 7 is a perspective view showing a portion of one form of the folding structure of the instant invention including one manner of forming a hinge between hollow rectangular members.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIG. 1, a folding structure 10 is disclosed formed in the shape of a substantially planar square having a side length eight times greater than its thickness or height. It will be understood that these dimensions have been found suitable for constructing one preferred embodiment of the present invention, but that these dimensions are not intended to be limitive and other dimensions may be substituted therefor to produce structures of differing shape but which fold in substantially the same manner as disclosed herein. For example, use of structural members of lesser thickness to produce a planar square having a greater than 8:1 side length to height ratio will, when folded form a rectangular structure having a height of lesser dimension than its side length rather than a cube as shown in the preferred embodiment. Other obvious variations in the size of the rectangular members employed in the instant invention are considered to be within the scope of the instant invention.
As illustrated, folding structure 10 includes a central square member 12 having a side length of four units, four rectangular side members 14, 16, 18 and 20 positioned adjacent each of the sides of square member 12 and having a length of four units and a width of two units, and four corner members 22, 24, 26 and 28 having side lengths of two units.
While the surface configuration of the folding structure 10 is shown for clarity on the drawings to be unlined, as stated heretofore, a checked pattern may be imposed thereon by means of decoration or by constructing each of the members 12-28 from a plurality of individual cubes of light and dark shades having a side length of one unit, the light and dark cubes being interconnected alternately with respect to each other. It will further be understood that the size of the folding structure 10 may vary widely depending, for example, upon whether the folding structure is to be employed as a relatively small chessboard, a relatively large piece of furniture, or for any other purpose. Variation in size may be easily accomplished by changing the size of the "units" in terms of which the side length to height ratios have been previously discussed.
As seen in FIG. 1, hinges 30, 32, 34 and 36 are provided to interconnect the corner members 22-28 with the end portions of the side members 14 and 18. Hinges 30 and 32 and hinges 34 and 36 define a pair of parallel lines spaced on lateral sides of central square member 12. Referring now to FIG. 2, wherein the bottom portion of folding structure 10 is illustrated, it will be seen that hinges 38, 40, 42 and 44 are provided interconnecting the corner units 22-28 to the opposed ends of side members 16 and 20, while hinges 46 and 48 interconnect the side members 14 and 18 with center square member 12. Thus the hinges 38, 40 and 46 and the hinges 42, 44 and 48 also define a pair of parallel lines spaced on the lateral sides of central square member 12 and transverse the parallel lines defined by hinges 30, 32 and 34, 36. Referring to FIG. 1, it will be understood that the hinges 30-36 are mounted at the adjacent top corners of the members which they interconnect, while the hinges 38-48 are positioned on the bottom corners of the structural members which they interconnect. This top or bottom corner positioning of the hinges allows the structural members to fold one on top of the other in the manner to be described hereafter with reference to FIGS. 3-6.
Flexible cord 50 is shown in FIG. 1 to extend through laterally spaced drilled holes 52 and 54 in square block 12, outwardly to side members 14 and 18, through drilled holes 56 in side member 14 and 58 in side member 18, and thence toward attachment points 60 and 62 on corner blocks 22 and 26 respectively. Finger gripping beads or knobs 64 and 66 are fastened to the ends of cord 50 to allow the cord to be easily gripped in order to unfold the folding structure from the cube to the planar square form as will be discussed hereafter. Flexible cord 50 forms a loop portion 68 in FIG. 1 between holes 52 and 54 which loop may be gripped and pulled upwardly to cause the structure 10 to fold to the cube form.
As seen in FIG. 1, the top openings of holes 52 and 54 in central block member 12 are spaced with respect to each other, and with respect to the block itself, such that the loop 68 formed by cord 50 extends essentially over the central portion of the block. The central positioning of the loop allows block 12 to be substantially balanced horizontally beneath the loop as the upward pulling force is exerted thereon during folding of the block to cube form. While holes 52 and 54 are shown to extend substantially vertically through block 12, it will be understood that these holes may also be drilled at an angle to the vertical.
Holes 56 and 58 in side members 14 and 18 are shown positioned near the ends of the members adjacent corner blocks 22 and 26 respectively. It has been found that this end positioning of the holes improves the folding characteristics of the structure and reduces the tendency of the cord to become entangled with the blocks during folding. Attaching points 60 and 62 are shown centered respectively on corner blocks 22 and 26 and it will be understood that the attachment of the cord thereto can be made in a variety of ways such as through the use of a staple or by cementing the cord thereto such that the end portions of the cord extending from the attaching points 60 and 62 outwardly to the gripping members 64 and 66 are of a fixed length while at the same time the remaining central portion of the cord extending from the connecting points 60 and 62 inwardly to loop 68 is freely slidable through the holes in structural members 12, 14 and 18. The holes in the structural members are sized to be only slightly greater in diameter than the cord 50 such that the cord is freely movable therethrough. Aligned grooves 70 and 72 may be formed on the top surfaces of side members 14 and 18 and corner blocks 22 and 26, as well as between the top openings of holes 52 and 54 in block 12 if desired, sized to receive the cord 50 and retain it below the top surface level of the foldable structure 10 to provide a more pleasing appearance and additionally to prevent the cord from becoming entangled with playing pieces should the folding structure be used as a chess or checker board or the like. Additionally, a clasp, button or similar device may be affixed to the cord at its central loop portion 68 for ease and convenience in pulling the cord at that point, and a corresponding by sized recess may be provided centrally on the top surface of block 12 to hold the clasp below the playing surface in the manner of grooves 70 and 72.
Referring now to FIGS. 3-6, the semi-automatic folding of the structure 10 in response to the upward pulling of loop 68 will be described. FIG. 3 discloses that the upward pulling of loop 68 initially raises center block 12 and side members 16 and 20 and causes side members 14 and 18 and their adjacent interconnected corner members to fold downwardly with respect to block 12 and the side members 16 and 20. On one lateral side of the structure 10, corner squares 22 and 28 pivot respectively about hinges 38 and 40, while side member 14 pivots about hinge 46. On the opposite side of the structure corner blocks 24 and 26 pivot respectively about hinges 44 and 42 while side block 18 pivots about hinge 48.
Referring additionally to FIG. 4, it will be seen that additional upward pulling on loop 68 causes the members 22, 14, 28 and 24, 18, 26 to continue their pivoting movement until they are folded adjacent each other beneath center block 12 and side members 16 and 20. At this point it will be understood that the effective size of the top surface area of the folding structure has been halved.
Referring additionally to FIG. 5, it will be seen that additional upward pulling force applied to loop 68 causes the end units formed by side member 20 and corner members 26 and 28 and side member 16 and corner members 22 and 24 to begin folding downwardly beneath the central structural composite formed by square member 12 and side members 14 and 18. The actual pivoting of the end units is carried out respectively about hinges 34 and 36 and hinges 30 and 32. Referring additionally to FIG. 6, the cubic form of the structural unit 10 attained upon completion of the folding action of FIG. 5 is illustrated.
It will be understood that the mechanism whereby the structural members are folded from the planar square form illustrated in FIG. 1 to the cube form shown in FIG. 6, in response to upward pulling on loop 68, involves the shortening of the portions of the cord 50 extending between drilled hole 52 and attachment point 60 and between drilled hole 54 and attachment point 62 and the corresponding increasing of the portion of the cord extending out of the top openings of holes 52 and 54 to form a loop 68. Although not illustrated in the drawings, it will be understood that when the cube form of the structure shown in FIG. 6 has been reached, the portion of cord 50 extending between attaching points 60 and 62 and the top openings of holes 52 and 54 is drawn tightly therebetween and cannot be additionally shortened because of the surface contact of the folded members forming the cube. Upward pulling force on loop 68 prevents the cube from unfolding although setting the folded cube on its bottom surface as shown in FIG. 6 also prevents the cube from unfolding by itself.
As seen in FIG. 6, after the cube form of the folding structure has been reached, the ends of cord 50 extend outwardly from the cube such that hand grips 64 and 66 may be pulled to cause the structure to semi-automatically unfold to the planar square form of FIG. 1. The movement of the component members of the folding structure from the cube form to the planar square form is the opposite of the movement from the planar square to the cube form discussed heretofore i.e., the unfolding movement is illustrated serially in FIGS. 6, 5, 4, 3, and 1 taken in that order. Again, the unfolding of the folding structure from the cube to the planar square form is accomplished by exerting opposing forces on the ends of cord 50 thereby decreasing the portion of the cord used to form loop 68 and increasing the portions of the cord extending between the bottoms of holes 52 and 54 and attaching points 60 and 62.
Referring to FIG. 7, one mode of constructing and hingedly interconnecting the structural members of the instant invention is disclosed. Corner members 74 and 76 are shown pivotally interconnected by means of fabric hinges 78 and 80 to a side member 82. As mentioned heretofore, side member 82 is equal to the combined size of the corner members 74 and 76. Hinges 78 and 80 may comprise pieces of fabric or tape fastened by glue or the like to the inner surfaces of the interconnected structural members. Alternatively, other known forms of hinges such as piano hinges may be substituted therefor. The choice of hinge is related to the material used to fabricate the structural members themselves. As shown in FIG. 7, the structural members are hollow and are formed of plastic or wood side sections 84 and top and bottom sections 86. In other embodiments the structural members may be formed from solid pieces of wood, metal, plastic or polyurethane foam or the like as desired. Further as mentioned heretofore, hollow structural members may also be provided with opening means 87 allowing the folding structure to be used for storage.
As illustrated, the hinges extend substantially completely along the corner edges of the joined adjacent structural members, but it will be understood that smaller individual laterally spaced hinges may also be satisfactorily substituted therefor. In selecting suitable hinges, it is important that they not be of excessive size so as to interfere with the complete folding of the structural members.
Referring again to FIGS. 1 and 2, it will be seen that the instant invention comprises a structure formed from a plurality of structural members including corner members 22, 24, 26 and 28, a first opposite pair of side members 14 and 18 and a second opposite pair of side members 16 and 20 and a square center member 12. The corner members, side members and center member are related to each other in size as 1:2:4. The corner members and side members form a rectangular border around the central square member 12. The rectangular border being comprised of alternating corner members and side members interconnected by a single hinge between each adjacent member, pairs of hinges about the border being alternately positioned on the top surface and bottom surface of the structural members. A single pair of bottom surface hinges extending between side members 14 and 18 and the center member 12 are the only connections between the rectangular border and the central square member. Thus the corner members as well as side members 16 and 20 are not directly hinged to the center member 12.
A folding rectangular chess board 14 inches on a side and foldable to form a cube having a 7 inch side length has been formed in accordance with the teaching of this invention by the interconnection of 64 solid wood cubes having a side length of 13/4 inches. In this embodiment, the corner members were formed by the rigid interconnection by means of glue or the like of four of the solid wood cubes, the side members formed by the rigid interconnection of eight of the solid wood cubes and the center section formed by the rigid interconnection of 16 of the solid wood cubes. The 64 cubes themselves were comprised of 32 cubes of a light colored wood and 32 cubes of a dark colored wood and in forming the chessboard the cubes of light and dark wood were alternated in the standard chessboard or checkerboard fashion. It will of course be understood that the folding structure of the instant invention may be formed to be of any desired size by the fabrication of larger or smaller corner, side and center structural members proportioned in accordance with the above disclosure.
The invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein.
1. Field of the Invention
This invention relates, in general, to a uniquely folding structure, and in particular, to a structure comprising a plurality of rectangular members hingedly interconnected to semi-automatically fold from a square to a cube or from a cube to a square in response to manipulation of a single cord running through or connected to selected rectangular members.
2. Description of the Prior Art
The interconnection of cube shaped units by means of cords to form a puzzle or amusement device is known per se. For example, U.S. Pat. Nos. 3,487,578 and 3,222,072 disclose puzzles of this type. Neither of these patents disclose the use of a flexible cord to manipulate the folding of the cubes with respect to each other, but rather the cord merely acts to interconnect the cubes. U.S. Pat. Nos. 3,550,310, 3,596,396 and 3,628,261 disclose other forms of cube puzzles all of which differ substantially from the instant invention with respect to both the shape of the interconnected members, the position of the hinges interconnecting the members, the location and function of the cord running through the members and the novel and intriguing operation thereof whereby the structure may be semi-automatically folded and unfolded between planar square and cube configurations.
Other patents illustrating the scope of the prior art but deemed to be substantially less relevant to the instant invention include U.S. Pat. Nos. 3,201,894; 3,577,673; 2,228,110; 926,365; 2,064,826; 2,334,486; 3,360,806; 3,462,150 and 2,880,001.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a folding structure comprising a plurality of three dimensional rectangular members hingedly interconnected to fold between a square having a thickness of one unit and a side length of eight units and a cube having a side length of four units in response to pulling force applied to either the center or ends of a string interconnecting some of the rectangular members. The invention thus provides unique means for rapidly stacking a plurality of rectangular members in a stable, compact shape for storage.
In one embodiment, the surface decoration of the rectangular members may include alternating light and dark squares such that when the structure is in the planar square form it forms a chess or checker board. Alternately, the rectangular members may be hollow and each include a closable opening whereby they may be used to store a plurality of like items of varying size such as nuts, bolts, washers or the like.
It is an object of the present invention, therefore, to provide a folding structure adapted to be semi-automatically folded between a first planar square form and a second cube form.
Another object of the instant invention is to provide a folding structure having a single flexible cord extending through or interconnected with some of the hingedly interconnected rectangular members whereby a pulling force exerted on the ends of the cord causes the block to unfold from a cube to a square while a pulling force exerted on the center portion of the cord causes the structure to fold from a square to a cube.
Still another object is to provide a game board which may be quickly and easily unfolded for use or folded for storage.
An additional object of the present invention is to provide a folding structure of the disclosed type which may be used as an article of furniture.
One more object of the present invention is to provide a folding structure of the disclosed type which may be used as a storage unit.
One more object is to provide a folding structure formed from a plurality of varying sized rectangular members some of which are interconnected with adjacent members by means of a first set of hinges positioned along parallel lines on a first surface of the planar square form of the structure and a second set of hinges positioned along parallel lines transverse said first parallel lines on the surface of said planar square opposite said first surface.
Other and additional objects and advantages will be apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a typical folding structure made according to the instant invention unfolded to form a planar square. FIG. 2 is a perspective view of the bottom portion of the folding structure of FIG. 1.
FIG. 3 is a perspective view of the folding structure of FIG. 1 wherein some of the members are being partially folded in response to an upward pulling force exerted on the center portion of the flexible cord.
FIG. 4 is a perspective view of the folding structure of FIG. 3 showing the structure after the folding action of FIG. 3 is completed.
FIG. 5 is a perspective view of the foldable structure of FIG. 4 wherein some of the rectangular members are being additionally folded in response to additional upward force on the center portion of the flexible cord.
FIG. 6 is a perspective view of the folding structure of FIG. 5 showing the folding structure completely folded to its cube form.
FIG. 7 is a perspective view showing a portion of one form of the folding structure of the instant invention including one manner of forming a hinge between hollow rectangular members.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIG. 1, a folding structure 10 is disclosed formed in the shape of a substantially planar square having a side length eight times greater than its thickness or height. It will be understood that these dimensions have been found suitable for constructing one preferred embodiment of the present invention, but that these dimensions are not intended to be limitive and other dimensions may be substituted therefor to produce structures of differing shape but which fold in substantially the same manner as disclosed herein. For example, use of structural members of lesser thickness to produce a planar square having a greater than 8:1 side length to height ratio will, when folded form a rectangular structure having a height of lesser dimension than its side length rather than a cube as shown in the preferred embodiment. Other obvious variations in the size of the rectangular members employed in the instant invention are considered to be within the scope of the instant invention.
As illustrated, folding structure 10 includes a central square member 12 having a side length of four units, four rectangular side members 14, 16, 18 and 20 positioned adjacent each of the sides of square member 12 and having a length of four units and a width of two units, and four corner members 22, 24, 26 and 28 having side lengths of two units.
While the surface configuration of the folding structure 10 is shown for clarity on the drawings to be unlined, as stated heretofore, a checked pattern may be imposed thereon by means of decoration or by constructing each of the members 12-28 from a plurality of individual cubes of light and dark shades having a side length of one unit, the light and dark cubes being interconnected alternately with respect to each other. It will further be understood that the size of the folding structure 10 may vary widely depending, for example, upon whether the folding structure is to be employed as a relatively small chessboard, a relatively large piece of furniture, or for any other purpose. Variation in size may be easily accomplished by changing the size of the "units" in terms of which the side length to height ratios have been previously discussed.
As seen in FIG. 1, hinges 30, 32, 34 and 36 are provided to interconnect the corner members 22-28 with the end portions of the side members 14 and 18. Hinges 30 and 32 and hinges 34 and 36 define a pair of parallel lines spaced on lateral sides of central square member 12. Referring now to FIG. 2, wherein the bottom portion of folding structure 10 is illustrated, it will be seen that hinges 38, 40, 42 and 44 are provided interconnecting the corner units 22-28 to the opposed ends of side members 16 and 20, while hinges 46 and 48 interconnect the side members 14 and 18 with center square member 12. Thus the hinges 38, 40 and 46 and the hinges 42, 44 and 48 also define a pair of parallel lines spaced on the lateral sides of central square member 12 and transverse the parallel lines defined by hinges 30, 32 and 34, 36. Referring to FIG. 1, it will be understood that the hinges 30-36 are mounted at the adjacent top corners of the members which they interconnect, while the hinges 38-48 are positioned on the bottom corners of the structural members which they interconnect. This top or bottom corner positioning of the hinges allows the structural members to fold one on top of the other in the manner to be described hereafter with reference to FIGS. 3-6.
Flexible cord 50 is shown in FIG. 1 to extend through laterally spaced drilled holes 52 and 54 in square block 12, outwardly to side members 14 and 18, through drilled holes 56 in side member 14 and 58 in side member 18, and thence toward attachment points 60 and 62 on corner blocks 22 and 26 respectively. Finger gripping beads or knobs 64 and 66 are fastened to the ends of cord 50 to allow the cord to be easily gripped in order to unfold the folding structure from the cube to the planar square form as will be discussed hereafter. Flexible cord 50 forms a loop portion 68 in FIG. 1 between holes 52 and 54 which loop may be gripped and pulled upwardly to cause the structure 10 to fold to the cube form.
As seen in FIG. 1, the top openings of holes 52 and 54 in central block member 12 are spaced with respect to each other, and with respect to the block itself, such that the loop 68 formed by cord 50 extends essentially over the central portion of the block. The central positioning of the loop allows block 12 to be substantially balanced horizontally beneath the loop as the upward pulling force is exerted thereon during folding of the block to cube form. While holes 52 and 54 are shown to extend substantially vertically through block 12, it will be understood that these holes may also be drilled at an angle to the vertical.
Holes 56 and 58 in side members 14 and 18 are shown positioned near the ends of the members adjacent corner blocks 22 and 26 respectively. It has been found that this end positioning of the holes improves the folding characteristics of the structure and reduces the tendency of the cord to become entangled with the blocks during folding. Attaching points 60 and 62 are shown centered respectively on corner blocks 22 and 26 and it will be understood that the attachment of the cord thereto can be made in a variety of ways such as through the use of a staple or by cementing the cord thereto such that the end portions of the cord extending from the attaching points 60 and 62 outwardly to the gripping members 64 and 66 are of a fixed length while at the same time the remaining central portion of the cord extending from the connecting points 60 and 62 inwardly to loop 68 is freely slidable through the holes in structural members 12, 14 and 18. The holes in the structural members are sized to be only slightly greater in diameter than the cord 50 such that the cord is freely movable therethrough. Aligned grooves 70 and 72 may be formed on the top surfaces of side members 14 and 18 and corner blocks 22 and 26, as well as between the top openings of holes 52 and 54 in block 12 if desired, sized to receive the cord 50 and retain it below the top surface level of the foldable structure 10 to provide a more pleasing appearance and additionally to prevent the cord from becoming entangled with playing pieces should the folding structure be used as a chess or checker board or the like. Additionally, a clasp, button or similar device may be affixed to the cord at its central loop portion 68 for ease and convenience in pulling the cord at that point, and a corresponding by sized recess may be provided centrally on the top surface of block 12 to hold the clasp below the playing surface in the manner of grooves 70 and 72.
Referring now to FIGS. 3-6, the semi-automatic folding of the structure 10 in response to the upward pulling of loop 68 will be described. FIG. 3 discloses that the upward pulling of loop 68 initially raises center block 12 and side members 16 and 20 and causes side members 14 and 18 and their adjacent interconnected corner members to fold downwardly with respect to block 12 and the side members 16 and 20. On one lateral side of the structure 10, corner squares 22 and 28 pivot respectively about hinges 38 and 40, while side member 14 pivots about hinge 46. On the opposite side of the structure corner blocks 24 and 26 pivot respectively about hinges 44 and 42 while side block 18 pivots about hinge 48.
Referring additionally to FIG. 4, it will be seen that additional upward pulling on loop 68 causes the members 22, 14, 28 and 24, 18, 26 to continue their pivoting movement until they are folded adjacent each other beneath center block 12 and side members 16 and 20. At this point it will be understood that the effective size of the top surface area of the folding structure has been halved.
Referring additionally to FIG. 5, it will be seen that additional upward pulling force applied to loop 68 causes the end units formed by side member 20 and corner members 26 and 28 and side member 16 and corner members 22 and 24 to begin folding downwardly beneath the central structural composite formed by square member 12 and side members 14 and 18. The actual pivoting of the end units is carried out respectively about hinges 34 and 36 and hinges 30 and 32. Referring additionally to FIG. 6, the cubic form of the structural unit 10 attained upon completion of the folding action of FIG. 5 is illustrated.
It will be understood that the mechanism whereby the structural members are folded from the planar square form illustrated in FIG. 1 to the cube form shown in FIG. 6, in response to upward pulling on loop 68, involves the shortening of the portions of the cord 50 extending between drilled hole 52 and attachment point 60 and between drilled hole 54 and attachment point 62 and the corresponding increasing of the portion of the cord extending out of the top openings of holes 52 and 54 to form a loop 68. Although not illustrated in the drawings, it will be understood that when the cube form of the structure shown in FIG. 6 has been reached, the portion of cord 50 extending between attaching points 60 and 62 and the top openings of holes 52 and 54 is drawn tightly therebetween and cannot be additionally shortened because of the surface contact of the folded members forming the cube. Upward pulling force on loop 68 prevents the cube from unfolding although setting the folded cube on its bottom surface as shown in FIG. 6 also prevents the cube from unfolding by itself.
As seen in FIG. 6, after the cube form of the folding structure has been reached, the ends of cord 50 extend outwardly from the cube such that hand grips 64 and 66 may be pulled to cause the structure to semi-automatically unfold to the planar square form of FIG. 1. The movement of the component members of the folding structure from the cube form to the planar square form is the opposite of the movement from the planar square to the cube form discussed heretofore i.e., the unfolding movement is illustrated serially in FIGS. 6, 5, 4, 3, and 1 taken in that order. Again, the unfolding of the folding structure from the cube to the planar square form is accomplished by exerting opposing forces on the ends of cord 50 thereby decreasing the portion of the cord used to form loop 68 and increasing the portions of the cord extending between the bottoms of holes 52 and 54 and attaching points 60 and 62.
Referring to FIG. 7, one mode of constructing and hingedly interconnecting the structural members of the instant invention is disclosed. Corner members 74 and 76 are shown pivotally interconnected by means of fabric hinges 78 and 80 to a side member 82. As mentioned heretofore, side member 82 is equal to the combined size of the corner members 74 and 76. Hinges 78 and 80 may comprise pieces of fabric or tape fastened by glue or the like to the inner surfaces of the interconnected structural members. Alternatively, other known forms of hinges such as piano hinges may be substituted therefor. The choice of hinge is related to the material used to fabricate the structural members themselves. As shown in FIG. 7, the structural members are hollow and are formed of plastic or wood side sections 84 and top and bottom sections 86. In other embodiments the structural members may be formed from solid pieces of wood, metal, plastic or polyurethane foam or the like as desired. Further as mentioned heretofore, hollow structural members may also be provided with opening means 87 allowing the folding structure to be used for storage.
As illustrated, the hinges extend substantially completely along the corner edges of the joined adjacent structural members, but it will be understood that smaller individual laterally spaced hinges may also be satisfactorily substituted therefor. In selecting suitable hinges, it is important that they not be of excessive size so as to interfere with the complete folding of the structural members.
Referring again to FIGS. 1 and 2, it will be seen that the instant invention comprises a structure formed from a plurality of structural members including corner members 22, 24, 26 and 28, a first opposite pair of side members 14 and 18 and a second opposite pair of side members 16 and 20 and a square center member 12. The corner members, side members and center member are related to each other in size as 1:2:4. The corner members and side members form a rectangular border around the central square member 12. The rectangular border being comprised of alternating corner members and side members interconnected by a single hinge between each adjacent member, pairs of hinges about the border being alternately positioned on the top surface and bottom surface of the structural members. A single pair of bottom surface hinges extending between side members 14 and 18 and the center member 12 are the only connections between the rectangular border and the central square member. Thus the corner members as well as side members 16 and 20 are not directly hinged to the center member 12.
A folding rectangular chess board 14 inches on a side and foldable to form a cube having a 7 inch side length has been formed in accordance with the teaching of this invention by the interconnection of 64 solid wood cubes having a side length of 13/4 inches. In this embodiment, the corner members were formed by the rigid interconnection by means of glue or the like of four of the solid wood cubes, the side members formed by the rigid interconnection of eight of the solid wood cubes and the center section formed by the rigid interconnection of 16 of the solid wood cubes. The 64 cubes themselves were comprised of 32 cubes of a light colored wood and 32 cubes of a dark colored wood and in forming the chessboard the cubes of light and dark wood were alternated in the standard chessboard or checkerboard fashion. It will of course be understood that the folding structure of the instant invention may be formed to be of any desired size by the fabrication of larger or smaller corner, side and center structural members proportioned in accordance with the above disclosure.
The invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein.