Technical Field

This invention relates to tne rield or mecnanicai loσic puzzles. The invention is particularly concerned with Duzzles having a numoer or elements wnich can oe moveα n certain limited ways to form various arrangements , and tne aim of wnicn is to move the elements from a random arranσement into a predetermined pattern.

Background Art

One of the earliest and best known puzzles in this rield is the "Fifteen Puzzle" in wnich fifteen square pieces are contained within a frame which can acco odate sixteen such pieces, with the pieces being moved by sliding in a flat plane.

A number of three-dimensional puzzles are based on the same principle as the Fifteen Puzzle , typically having cuoical pieces which are contained within a larger cubical container which has a vacant space equivalent to the volume of one of the movable pieces. In these puzzles the pieces can slide in three dimensions.

Some three-dimensional puzzles allow for rotation of cuoical pieces as well as translation, such as the puzzles disclosed in the patents US 4,036,503, US 4,488,725 and US 4,424,971.

In the "Rubik's Cube" puzzle a number of partly cubical Dieces are contained in the puzzle structure oy an internal αevice rather than an external container, and the pieces can be moved by rotatinσ m layers.

Disclosure of Invention

In tnis invention a nu oer or movable polyhedral or polygonal Dieces are connected to a main Dolyhedral structure. The

movable pieces are each positioned with one of their faces against the faces of the main polyhedral structure when at rest. One of the polyhedral faces has no piece positioned against it, and the pieces can be moved when adjacent to this vacant position by rotating and translating onto the vacant face. If polyhedral pieces are employed, they can be contained within a main polyhedral structure or they can be positioned on its exterior. If substantially flat polygonal pieces are employed, they would be movabley attached to the exterior of the main polyhedral structure. The main polyhedral structure can be real or imaginary. The polyhedral pieces need not be regular solid polyhedra, but can have any variation to their basic shape which facilitates their movement or helps support them in place when at rest. The pieces carry markings on them and the aim of the puzzle is to arrange them in a predetermined pattern.

Where polyhedral pieces are contained within the main polyhedral structure they can either be moved by force of gravity alone as the sealed structure is reoriented in space or they can be manually pushed through openings in the main polyhedral structure. The pieces can be supported in place by contact with other pieces or with the help of additional devices within the main structure.

Where polyhedral or polygonal pieces are positioned on the exterior of the main structure, they can be attached to the main structure by a device linking them to the core of the main structure which allows them to rotate over the surface of the polyhedral structure without becoming detached from it. This device could take the form of an arm or wire fitting at one end into a continuous groove running over all faces of the polyhedral or polygonal pieces and at the other end into a continuous groove in the core of the main structure. The core would be attached to the faces of the main structure by struts which allow for a continuous aperture running throuσh all the faces of the main structure through which the arm or wire linking the pieces to the core can move as the pieces cnange

position .

The main advantages of this invention over other puzzles in the field are that the pieces move in a novel way; the rotation of the pieces allows for a greater number of possible arrangements of the pieces and greater complexity of the puzzle; and the polyhedral form of the puzzle makes it more aesthetically attractive.

Figures in the Drawings

Figure 1 shows an example of the invention in icosahedral form, illustrating the main polyhedral structure and one of the pieces.

Figure 2 shows an internal view of the polyhedral container and one of the pieces.

Figure 3 shows a cross-section of the puzzle container, some of the pieces, and a central supporting object.

Figure 4 shows the use of a polyhedral container with openings through which the pieces are manually pushed to move them.

Best Mode for Carrying Out the Invention

The best mode for carryinq out the invention would take the form of an icosahedral main structure containing nineteen substantially tetrahedral pieces within it. The faces of the pieces would be slightly smaller than the faces of the container, and the pieces would rest with one of their faces positioned against a face of the container with the edges of both faces parallel. One of the three pieces with an edge adjacent to the vacant face of the container can change position by rotating around that edge to move into the vacant position with a different face positioned against the face of the container, and the vacant position is transferred to the former position of the piece which has moved. The container would be mainly transparent. The pieces would have markings on one face but would be otherwise transparent, so that the markings on that face can be seen in reverse through

the body of the piece when the marked face is not positioned against a face of the container. The markings on the pieces could together form an overall pattern such as a world map.

Figure 1 illustrates the basic structure of such a puzzle. The transparent container 1 and a tetrahedral piece 2 are shown. The position of the piece within the container is also shown. Its face A is resting against a face of the container. This piece can change position when the vacant position appears at the faces C, D, or E of the container. When it does so, the face of the piece sharing with face A the edge of the piece which is adjacent to the vacant position will be positioned against the face of the container after the piece has moved. For example, if the vacant position is at face C of the container, after the piece moves its face B will be positioned against face C.

Figure 2 shows part of the interior of the container 4 and one of the pieces 3. The broken lines indicate how it would be positioned against the face F of the container. This piece could rotate about one of its edges to be positioned with a different face against face G, H, or I of the container. Ridoes 7 could be employed on the interior edges of the container to facilitate the rotation of the pieces. The corners 5 and edges 6 of the pieces could be truncated to accomodate the movement of the pieces. Other variations in the shape of the pieces which would accomodate their movement are also possible.

Figure 3 shows a cross-section of the puzzle container 8 and some of the pieces 9 within it. A central supporting object 10 is also shown. This device may be necessary to help support the pieces neatly in place when at rest. It could be rigid or it could be resilient or have spring-loaded sections pushing the pieces outwards against the container faces. The pieces could rest in contact with adjacent pieces or they could be in contact only with the central supporting object 5 and the container faces, thereby leaving greater space between the pieces to accomodate their movement. The central

object could have parts attached to it which fit between the sides of adjacent pieces to hold them in place when at rest and pivot to allow movement of the pieces.

Figure 4 shows the use of openings 11 in the container faces through which the pieces can be manually pushed. This figure also shows that parts of the pattern constituted by the markings on the pieces, which it is the object of the puzzle to properly arrange, could be attached to the container itself. This would be necessary because there would be gaps in the pattern at the edges of the container due to the smaller size of the faces of the pieces, and because there is one piece less than the total number of faces of the container, so a part of the pattern corresponding to one face of the container would otherwise be missing. This is addressed by having part of the pattern attached to the edges 13 of the container and one of the faces 12.

The container structure could be partly flexible to allow slight distortions in its shape to create extra space to accomodate the rotation of the pieces.

Devices might be used to hold the pieces in place when at rest and prevent accidental movements. Such devices could take the form of pin elements inserted through openings in the container and fitting between adjacent pieces.

The pieces might not rotate directly about the edges of the container but may first slide towards the edges before rotating, then slide towards the centre of the new position after rotation. This movmement would allow more space to accomodate the rotation of the pieces.