BACKGROUND OF THE INVENTION THIS INVENTION relates to puzzles in the form of mechanical contrivances which require a degree of intellect or patience to solve, as well as some manual dexterity. The invention is particularly concerned with puzzles which are solved by inserting a member having an elongate aperture into a series of loops held on individual supports, and, then, removing the member from the loops.

Puzzles of this nature have been known for many years and are described in, for instance, British patent specification No. 18,840, French patent specification No. 754,143, Italian patent specification No. 640,807, U.S. patent specification No. 3,698,719 and, more recently, in Australian patent specification No. 82,192/87.

The problem with these puzzles is that they are too complicated to solve for the majority of people. This is because they comprise too many loops or rings and it requires a very lengthy series of steps which must be rigidly followed to place the elongated aperture through the rings. The difficulty in solving the puzzles increases exponentially as the number of rings increases and such puzzles generally have from 5 to 7 rings. The problem can be addressed by having only a few, say three, rings however, the puzzle can then be mastered very quickly and there is no longer any challenge.

OBJECT OF THE INVENTION It is an object of the present invention to provide an improvement in these existing ring puzzles so that they will give a continuing challenge to people of all age groups and intellectual capacities.

SUMMARY OF THE INVENTION According to the present invention, there is provided a puzzle comprising two components for interlocking or unlocking to provide a solution thereof, one of said components consisting of a base structure

having a plurality of interlocking segments from two or more of which project a plurality of loop retainers arranged in a row in spaced apart relationship, each said loop retainer having a stem and a head portion which is adapted to retain a closed loop in relative movable relationship therewith, each said closed loop, with the exception of the first loop in the row, encircling the loop retainer of an adjacent preceding loop, and each said loop retainer being independently movable toward and away from the base structure; the other of said components comprising a longitudinally extending billet having a longitudinal opening, said billet having a section which can extend through all said closed loops and wherein the closed loops can pass through the longitudinal opening of that section.

The construction of the two interlocking components is such that by relative manipulation of the components in a particular sequence of steps, the longitudinally extending billet can be locked together with all the closed loops in such a manner that the two components cannot be disengaged. Only reversal of the sequence enables disengagement of the interlocking components. It is not obvious how the interlocking of the components can be achieved without a considerable amount of trial and error, and this gives rise to a large degree of mental aptitude in trying to find the solution and then being able to apply that knowledge in unlocking the components. Having "solved" the puzzle, it then comes down to being able to do both operations in the shortest possible time.

This sequence of interlocking of the components is described hereinafter in detail.

The main feature of the invention is the provision of a base structure which comprises a plurality of interlocking segments. This enables a puzzle to be constructed by the user selecting the required number of segments which, when interlocked give the number of loops which the user feels that he or she can readily solve.

Thus, initially the user will begin with three loops and will fit together the minimum two pieces of base structure required to give this structure. Once having mastered this arrangement, the user will then disassemble the base structure, add an extra loop supporting segment and reassemble the structure so that it now has four loops.

In this manner the user proceeds to more complicated levels of the puzzle in easy to manage steps, and is always presented with a challenge without becoming frustrated on the way.

The segments of the base structure can be in the form of blocks which interlock together and are held by frictional forces, or elements which are fitted together by mechanical fasteners or the like. One preferred base structure comprises a plurality of hollow blocks moulded from plastics material which are fitted side-by-side. Such a structure can include provision for a loop retainer to be placed in an aperture formed between adjacent blocks, or can have one or more shaped apertures in the individual blocks themselves into which the loop retainers are inserted.

Another desirable base structure comprises a plurality of segments manufactured from timber, plastics material or metal, or a combination of these materials. Each segment consists of two parts - a compartment and a lid. Each lid is slidable longitudinally with respect to its compartment and can be fixed thereto by screws or the like if required. Suitably, each lid, with the exception of the lid on the first compartment extends past the end wall of the compartment to enable mating with the top wall of an adjacent compartment. Permanent fixing between adjacent segments can be effected by fitting screws through the overlapping lid of one segment into the compartment wall of the adjacent segment.

The closed loops will each suitably be of the same shape and size, although this is not essential for the production of a working puzzle. Preferably, the

closed loops are elliptical or circular in shape with uniform diameter rings being the most preferred form. Such loops or rings can be designed to be opened, as in the case of key rings, to facilitate connection to the loop retainers.

The loop retainers are constructed so as to permit free movement of the closed loops relative thereto. That is, the loop retainers support or restrain the closed loops while enabling the closed loops to move within the loop retainers. To this end, each closed loop can be accommodated by an oversized opening in the head portion of the loop retainer which permits the closed loop to have lateral and vertical movement therein.

The loop retainers are suitably of rigid construction to provide appropriate support for the closed loops and have limited movement through or relative to the base structure. Preferably, the stem of each loop retainer can move through the base structure so as to enable easy manipulation of the associated closed loop when it is being threaded through the longitudinal billet as hereinafter described. In such an arrangement, each loop retainer can extend through an opening in the base structure and be restrained from being removed therefrom by an oversized attachment on it's lower end which projects on the opposite side of the base structure to which the closed loops are located.

The longitudinally extending billet having a longitudinal opening can comprise any constructional configuration falling within the prescribed functional limitations of having a section which can be passed through the closed loops and having an opening in that section which is dimensioned to enable each closed loop to pass through it. To this end, the billet may be constructed from a flat slab or a rod or bar. One preferred construction is a rod which is bent through 180 degrees and joined at it's free ends to a handle to permit ready manipulation. Another particularly suitable construction is an adjustable size billet. This

comprises a basic structure to which additional extensions can be added. For instance, one practical embodiment consists of a U-shaped rod having a handle closing-off the free ends. The handle is removable from the free ends, on which it is, for instance, frictionally engaged, and additional rods are connectable to those free ends such as by the use of a screw-threaded attachment and a threaded collar, or the like. The new free ends of the extended section are then inserted back into the handle to provide the longer length billet. Such a billet is particularly suitable for use with the adjustable length base structure as it enables a compatible size to be used therewith.

The puzzle can be manufactured from a wide range of materials which will primarily be dependant upon the target market. As an executive puzzle it can be manufactured from metal such as stainless steel, or steel which is chromed or gold plated. As a puzzle for children it can be manufactured from rigid plastics materials such as h.d. polyethylene, polyvinylchloride or the like. Combinations of materials may also be used. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention will now be described with reference to the accompanying drawings. The description of this embodiment will also provide details how the interlocking of the components is achieved. In the drawings:

Figure 1 is a perspective view of a puzzle according to one embodiment of the present invention; Figure 2 is a detailed exploded perspective view of a portion of the base structure of the Figure 1 embodiment;

Figure 3 is a detailed exploded view of the billet of the Figure 1 embodiment; Figure 4 is a plan view of a base structure according to a further embodiment of the present invention; and

Figure 5 is a side view of a ring and ring

retainer for use with the base structure depicted in Figure 4.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to Figure 1, a six-ring puzzle is depicted. This comprises a base structure 10, six rings

11, 12, 13, 14, 15, 16 supported by ring retainers 17,

18, 19, 20, 21, 22 and a longitudinally extending billet having a longitudinally opening 23.

The base structure comprises seven injection moulded hollow plastics blocks 24, 25, 26, 27, 28, 29, 30 which interlock together as shown in Figure 2. End blocks 24 and 30 are of identical structure, as are the intermediate blocks 25, 26, 27, 28, 29. Apertures 31, 32, 33, 34, 35, 36 are located at the junction of adjacent blocks and these provide positions from which the ring retainers extend.

The ring retainers have an enlarged lower end (not visible in the drawing) which enables them to be retained by the blocks and a looped upper end for connection to the individual rings.

The longitudinally extending billet 23 (see Figure 3 also) comprises a bent rod 37 whose ends 38, 39 are screw threaded to enable connection to extending rods 40, 41 with the use of screw threaded couplings 42, 43. The rods 40, 41 are frictionally engaged within handle 44.

Such a puzzle can be reduced in size to include a minimum of two blocks and two rings, by removing all but one of the intermediate blocks, or to any in-between size. Puzzles with more rings can be assembled but these will be extremely difficult to solve. This enables great adaptability and meets the previous objectives of the invention.

In order to solve the puzzle depicted in Figure 1, that is, to remove the billet from the rings, the following steps are necessary:

Start by pulling the billet 23 to the right until it stops at ring retainer 17. With the left hand

lift rings 11 and 12 up together around the left end of the billet. Slide the billet to the left and then drop both rings 11 and 12 down through the billet. Pull the billet to the right until it stops at ring retainer 19. Lift ring 14 up around the end of the billet and then drop ring 14 down through the billet. Push the billet to the left through ring 13 and over ring 12 as far as ring 11. Lift both rings 11 and 12 up through the billet by pushing them up with the second and third fingers of the left hand and then pinching them together with the thumb and first finger of the left hand as ring 11 and ring 12 emerge on top of the billet. Pull the billet to the right until it hits ring retainer 17 and then carefully drop ring 12 so that it fa--is around end of the billet. Push the billet to the left through ring 12 to ring 11, dropping ring 11 down through the billet. Pull the billet to the right until it stops at ring retainer 18 and lift ring 13 up around the end of the billet. Then drop ring 13 down through the billet and slide the billet left through ring 12 as far as ring 11. Lift ring 11 up through the billet and retain it with thumb and first finger of the left hand. Slide the billet to the right to ring retainer 17, and then with the second and third fingers of the left hand pick up ring 12 around the end of the billet. While holding rings 11 and 12 up together, slide the billet to the left past all the rings and then let rings 11 and 12 drop down through the billet. Hereafter the remainder of the instructions will be abbreviated, using B = billet; If = left; rt = right. Now continue as follows: B rt; 16 up around end of B; 16 down through B; B If through 15 over 14 and 12; 11 and 12 up through B; B rt; 12 down around end of B; B If; 11 down through B; B rt; 13 up through B; 13 down around end of B; B If through 13; 11 up through B; B rt; 12 up around end of B; B If; 11 and 12 down through B; B rt; 14 up through B; 14 down around end of B; B If through 13; 11 and 12 up through B; B rt; 12 down around end of B; B If; 11 down through B; B rt; 13 up around end

of B; 13 down through B; B If through 12; 11 up through B; B rt; 12 up around end of B; B If; 11 and 12 down through B; B rt; 15 up around end of B; 15 down through B; B If through 14 over 13; 11 and 12 up through B; B rt; 12 down around end of B; B If; 11 down through B; B rt; 13 up through B; 13 down around end of B; B If through 12; 11 up through B; B rt; 12 up around end of B; B If; 11 and 12 down through B; B rt; 14 up around end of B; 14 down through B; B If through 13; 11 and 12 up through B; B rt; 12 down around end of B; B If; 11 down through B; B rt; 13 up around end of B; 13 down through B; B If through 12; 11 up through B; B rt; 12 up around end of B; B If; 11 and 12 down through B; the billet is now free of the rings and ring retainers. To replace the rings, start at the last step and reverse the procedure. Simply substitute "down" for "up," "left" for "right,", etc. and by backing through the foregoing instructions step-by- step the puzzle will be completely reassembled.

Figure 4 illustrates an alternative form of base structure. This comprises a series of compartments 50, 51, 52 with associated lids 53, 54, 55. Lids 54 and 55 each include three apertures 56, 57, 58 and 59, 60 and 61 respectively into which loop retainers with attached rings of the type depicted in Figure 5 may be inserted and retained by rotating through ninety degrees. Obviously, the number and relative sizes of compartments may be varied, as may the number of apertures in their associated lids.

The lids are retained under a lip formed in the upper edge of the compartments and are adapted to be connected to an adjacent compartment by means of screws 62, 63, 64, 65, 66, 67.

The specific puzzle of Figure 4 can be utilized with from 2 to 6 rings and thus provides a wide range of challenges for all ages.