Abstract:
The mechanical puzzle of the present invention includes concentrically arrangeable cylinders in which a pin projects from a first cylinder to engage with a groove which forms a maze pattern on a concentrically adjacent second cylinder. The puzzle may be solved by rotating and advancing or retracting the cylinders with respect to one another to move the pin from a starting point through a continuous passage and to an ending point. The puzzle may have multiple cylinders with multiple pin/groove pairs, may have different pin/maze arrangements, may be constructed of plastic, wood, or other material, may include secret compartments, may vary in diameter and skill level to suit users of differing mental and physical abilities, and may have interchangeable components to minimize obsolescence from user fluency.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the field of mechanical puzzles, and more particularly to a puzzle which includes a plurality of cylinders of varying diameters which may be concentrically arranged inside one another such that a pin projection on one or more cylinders may be engageable with a groove which forms a maze on an adjacent cylinder, thereby allowing a user to advance, rotate, and/or retract one or more of the cylinders with respect to the adjacent cylinder to navigate the pin projection through the groove in an attempt to solve the puzzle either by aligning the cylinders with one another concentrically in a pre-determined position or by fully disengaging the cylinders from one another. 
       BACKGROUND OF THE INVENTION 
       [0002]    Mechanical puzzles have permeated societies around the world for thousands of years and are generally best known for their entertainment value to both adults and children. In addition to their amusement potential, mechanical puzzles may be used as aids for improving cognitive and/or physical skills where a user may have limited ability because of age (either very young or very advanced in years) or impairment. 
         [0003]    Currently available mechanical puzzles span a wide range, including, for instance, sequential movement puzzles. Generally, these puzzles require a user to physically manipulate pre-attached puzzle pieces to arrive at a solution based on color matching, pattern matching, or the like. Sequential movement puzzles come in a variety of shapes, sizes, configurations, and levels of difficulty. Manipulation of almost all sequential movement puzzles requires a considerable degree of mental skill and fine motor control, placing even the simplest puzzle out of reach of very young users and those with limited brain function or motor control. Further, although the initial solution to many sequential movement puzzles is often difficult, such as for Rubik&#39;s Cube, for example, it is typically the case that the solution may be successfully and easily duplicated once discovered, thereby significantly reducing the entertainment value of the puzzle. 
         [0004]    Conventionally available mechanical puzzles also include what are known in the art as dexterity challenges. One of the more commonly known puzzles in this category involves a labyrinth through which an accompanying ball is manipulated by carefully tilting the entire puzzle to avoid having the ball fall into randomly placed holes. Sinking the ball into any of the holes requires a user to begin the game again. Like sequential movement puzzles, however, dexterity challenges are also subject to reduced entertainment value over time because repetitive solving is so easily achieved once the series of physical manipulations necessary to successfully solve the puzzle becomes known. 
         [0005]    Additionally, where labyrinths are not equipped with a transparent cover to ensure that the ball does not become separated from the game, the game may be rendered useless by loss of the ball. Conversely, where a transparent cover is in place, the ball may become wedged between the cover and the labyrinth such that a user must stop the game to dislodge the ball, each interruption making it necessary to restart the game from the beginning. Like sequential movement puzzles, labyrinth puzzles require a great degree of fine motor control for successful manipulation. This generally places most labyrinth-type puzzles out of the reach of very young children and those with diminished control of the hands or arms. 
         [0006]    Finally, most conventionally available mechanical puzzles, including those mentioned supra, rely to a great degree on a user&#39;s vision for color or pattern matching (as with sequential movement puzzles) or visualization of a solution path (as with labyrinth-type puzzles). This factor removes most such puzzles from the ambit of yet another group of potential puzzle solvers who may be visually impaired. 
         [0007]    What is therefore needed is a mechanical puzzle which may be suitable for a wide range of users of different age groups, skill levels, and physical abilities. The ideal puzzle may be sized to fit a variety of different-sized grips to make it easy for both children and adults to grasp. 
         [0008]    Additionally, the ideal puzzle could be worked by most users regardless of limited mental ability or restricted range of motion in the hands or upper extremities. Moreover, the ideal puzzle could be worked by individuals without regard to limited or absent vision. Finally, the degree of difficulty of the ideal puzzle would be variable to accommodate most users and to minimize the possibility of user fluency and subsequent puzzle obsolescence. 
       SUMMARY OF THE INVENTION 
       [0009]    The mechanical puzzle of the present invention includes a set of concentrically arranged cylinders, which may include one or more cylinders with a pin projection and one or more cylinders bearing a groove which forms a maze. The pin projection may preferably be sized such that it easily engages with the groove and may be moved from a starting point through a continuous groove and toward an ending point by advancing, rotating, and/or retracting the cylinders with respect to one another. 
         [0010]    The puzzle of the present invention may be available in a variety of skill levels based either on degree of difficulty of the maze pattern or on visibility of the maze while working the puzzle. For example, easier versions may allow a user to view the maze while manipulating the puzzle, intermediate versions may allow a user to view only part of the maze while working the puzzle, and more difficult versions may occlude the maze from a user&#39;s view altogether while the puzzle is being worked. 
         [0011]    Mazes may range from very straightforward to very complex, further determining the degree of difficulty of the puzzle. The cylinder to be extracted may also be labeled with messages designed to come into a user&#39;s view successively as he progresses through the puzzle, thereby allowing the user gage his progress or compare his skills to the skills of others. 
         [0012]    The size of the puzzle, and more particularly the size of the outermost cylinder, may be available in different diameters to fit a variety of grips. The overall size of the puzzle may conceivably be any size as long as the relative size of the cylinders allows them to be concentrically arranged with respect to one another and leaves sufficient space between them to allow them to slide over one another while maintaining a pin-groove connection. 
         [0013]    The puzzle of the present invention may have multiple embodiments, including, but not limited to, a version in which a pin on a first cylinder projects inward to engage with an outwardly directed maze on a concentrically adjacent smaller cylinder; a version in which a pin on a first cylinder projects outward to engage with an inwardly directed maze on a concentrically adjacent larger cylinder; a version which includes a hidden canister which becomes accessible when the puzzle is successfully solved; versions with multiple concentrically arranged cylinders having a pin/maze combination between each pair of adjacent cylinders; and versions with multiple concentrically arranged cylinders having 2 oppositely disposed pins which are engageable with opposite sides of a single maze between them. 
         [0014]    The puzzle of the present invention may preferably be constructed of polyvinyl chloride (PVC) though the puzzle may conceivably be constructed from any of a number of other materials such as molded plastic or other polymer, metal, fiberglass, cardboard, wood, or even glass, for example. The potentially large number of possible maze patterns and visibility combinations may provide sufficient variety to make the puzzle suitable for virtually any user. Moreover, the availability of differently sized puzzles may make it optimal for users with varying degrees of mental capacity and physical ability. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which: 
           [0016]      FIG. 1  is an exploded perspective view of a first embodiment of the puzzle of the present invention which illustrates a first cylinder having a pin projecting from its outer surface and connected to a second cylinder bearing a groove which forms a maze on its inner surface; 
           [0017]      FIG. 2  is a cutaway perspective view of the puzzle of  FIG. 1  as assembled; 
           [0018]      FIG. 3  is a cross-sectional view of the puzzle of  FIGS. 1 and 2  taken through the projecting pin along line  3 - 3  and illustrating a first pin/groove arrangement; 
           [0019]      FIG. 4  is a cross-sectional view of the puzzle of  FIGS. 1 and 2  taken through the projecting pin along line  3 - 3  and illustrating a second pin/groove arrangement; 
           [0020]      FIG. 5  is a cutaway perspective view of a second embodiment of the puzzle of the present invention similar to the embodiment of  FIG. 2  except that the second cylinder is modified to include a closed end, a spring, an accommodation space, and a canister; 
           [0021]      FIG. 6  is a cutaway perspective view of a third embodiment of the puzzle of the present invention which is similar to the embodiment of  FIG. 2  but which further includes large-diameter handles on the first and second cylinders, a second pin on the outer surface of the second cylinder, and a third cylinder concentrically adjacent the second cylinder and having a maze on its inner surface; 
           [0022]      FIG. 7  is a cross-sectional view of the puzzle of  FIG. 6  taken through the projecting pins along line  7 - 7  and illustrating a first pin/groove arrangement; 
           [0023]      FIG. 8  is a cross-sectional view of the puzzle of  FIG. 6  taken through the projecting pins along line  7 - 7  and illustrating a second pin/groove arrangement; 
           [0024]      FIG. 9  is a cross-sectional view of the puzzle of  FIG. 6  taken through the projecting pins along line  7 - 7  and illustrating a third pin/groove arrangement; 
           [0025]      FIG. 10  is a cross-sectional view of the puzzle of  FIG. 6  taken through the projecting pins along line  7 - 7  and illustrating a fourth pin/groove arrangement; 
           [0026]      FIG. 11  is a cross-sectional view of the puzzle of  FIG. 6  taken through the projecting pins along line  7 - 7  and illustrating a fifth pin/groove arrangement; 
           [0027]      FIG. 12  is a schematic layout of a first maze pattern for use in the puzzle of the present invention; 
           [0028]      FIG. 13  is a schematic layout of a second maze pattern for use in the puzzle of the present invention; 
           [0029]      FIG. 14  is a schematic layout of a third maze pattern for use in the puzzle of the present invention; 
           [0030]      FIG. 15  is a schematic layout of a fourth maze pattern for use in the puzzle of the present invention; 
           [0031]      FIG. 16  is a schematic layout of a fifth maze pattern for use in the puzzle of the present invention; 
           [0032]      FIG. 17  is a schematic layout of a sixth maze pattern for use in the puzzle of the present invention; 
           [0033]      FIG. 18  is a schematic layout of a seventh maze pattern for use in the puzzle of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0034]    The description and operation of the invention will be best initiated with reference to  FIG. 1 , which is an exploded perspective view of a first embodiment of the invention seen as puzzle  21  of the present invention.  FIG. 1  illustrates a first cylinder  23  having a first end  25 , a second end  27 , an outer surface  31 , an inner surface  32 , and a pin  33  projecting from outer surface  31  near first end  25 . Although pin  33  may be any size, it may preferably be about ⅛ of an inch in diameter and may project about ⅜ of an inch away from outer surface  31 . Pin  33  may be formed integrally with the first cylinder  23 , may be formed and inserted in a bore formed in first cylinder  23 , or may be attached to first cylinder  23  in any other manner. 
         [0035]      FIG. 1  illustrates a second cylinder  35  having a first end  37 , a second end  41 , an outer surface  43  and an inner surface  45  into which a groove  47  is cut to form a maze pattern. Groove  47  may be formed by cutting, routing, pressure impression, or other manufacturing technique. Pin  33  on first cylinder  23  is slidably engageable with groove  47  at first end  37  of second cylinder  35 . First cylinder  23  may be advanced into second cylinder  35  by rotating one or both of cylinders  23  and  35  and moving cylinders  23  and  35  longitudinally toward one another where groove  47  permits or retracting them longitudinally away from one another to move pin  33  through groove  47  and toward second end  41  of second cylinder  35 . 
         [0036]    An optional lanyard  48  is shown connected to a first anchoring structure  49  on the inner surface  32  of first cylinder  23  adjacent second end  27  and to a second anchoring structure  50  on the outer surface  43  of second cylinder  35  adjacent first end  37 . Lanyard  48  may be included to ensure that first and second cylinders  23  and  35  remain in close proximity to one another when they are disjoined. Lanyard  48  may preferably be of a length which allows first cylinder  23  to be passed through second cylinder  35  to the extent necessary to completely solve puzzle  21 . Anchoring structures  49  and  50  are illustrated as eye loops but may be any structures which secure lanyard  48  and allow first cylinder  23  to be passed through second cylinder  35 , including structures that may even allow lanyard  48  to be released from either or both of cylinders  23  or  35 . 
         [0037]    First cylinder  23  may preferably be ⅞ of an inch in diameter, and second cylinder  35  may preferably be about 1 and ¼ inches in diameter, although the size of cylinders  23  and  35  may conceivably be any size as long as the relative size of cylinders  23  and  35  allows them to be concentrically arranged with respect to one another and leaves sufficient space between them to allow them to move slidably over one as pin  33  is manipulated through with groove  47 . 
         [0038]    Although cylinders  23  and  35  may conceivably be constructed of any of a variety of materials such as polymer, metal, fiberglass, cardboard, wood, or even glass, for example, they are preferably made of plastic or a similarly lightweight material. More visible, and possibly easier, versions of puzzle  21  may be achieved by constructing second cylinder  35  of a transparent material (such as plexiglass, for example) which would allow a user to view groove  47  while puzzle  21  is being worked. Cylinder  35  may also be mostly opaque but may include transparent portions so that a user may view some part of groove  47  while working puzzle  21 . Finally, second cylinder  35  may be constructed of a completely opaque material to force users to rely on mental acuity and memory to navigate pin  33  through groove  47 . 
         [0039]    Groove  47  may be machine-cut, using a computer-driven lathe, for example, or may be hand cut. Groove  47  may preferably be approximately 5/32 of an inch wide, or about 1/32 of an inch larger than pin  33 . Groove  47  may extend into inner surface  45  and only partially through second cylinder  35  or may extend completely through second cylinder  35  and outer surface  43 . Where groove  47  extends completely through second cylinder  35 , it may be necessary to reinforce outer surface  43  of second cylinder  35  to maintain its structural integrity, especially where groove  47  may completely bisect second cylinder  35  radially by design. 
         [0040]    Both cylinders  23  and  35 , and thus the overall size of puzzle  21 , may be sized to accommodate a wide range of grip sizes. For example, cylinders with bigger diameters may be more ideal for very young, very old, arthritic, or motor-challenged users because of their difficulty grasping small or narrow objects. Conversely, cylinders with smaller diameters may be desirable where there is a need to improve fine motor skills through physical therapy for injury or restricted range of motion, or even where a more compact version of puzzle  21  would be preferable (during travel, for example). 
         [0041]    First cylinder  23  may preferably be approximately 14 inches long and second cylinder  35  may be about 12 inches long. Although first and second cylinders  23  and  35  may be virtually any length, it may be preferable for first cylinder  23  to be about 2 inches longer than second cylinder  35  to allow a user enough room to comfortably grasp second end  27  of first cylinder  23  while working puzzle  21 . 
         [0042]      FIG. 2  is a cutaway perspective view of puzzle  21  of  FIG. 1  as assembled. First cylinder  23  is illustrated partially withdrawn away from (or alternatively only partially advanced toward, depending on the direction in which puzzle  21  is worked) second end  41  of second cylinder  35 . When a user approaches puzzle  21 , pin  33  may preferably be nearest to second end  41  of second cylinder  35 . A user may grasp second end  27  of first cylinder  23  adjacent first end  37  of cylinder  35  and proceed to manipulate first cylinder  23  with respect to second cylinder  35  and attempt to move pin  33  closer to first end  37  of second cylinder  35 . Successfully moving first cylinder  23  in the described direction may ultimately allow a user to extract first cylinder  23  from second cylinder  35 . 
         [0043]    Although puzzle  21  is described as being worked in a particular direction, users may work puzzle  21  in a first direction by advancing pin  33  on first end  25  of first cylinder  23  into groove  47  at first end  37  and toward second end  41  of second cylinder  35 , or, alternatively in a second direction by retracting pin  33  at first end  25  of first cylinder  23  away from second end  41  of cylinder  35  and toward (and ultimately out of) first end  37  of second cylinder  35 . Working the puzzle  21  in the first direction may be required to achieve the pin  33  placement necessary to work the puzzle in the second direction where groove  47  is accessible from only one end of second cylinder  35 . 
         [0044]    Although pin  33  is illustrated in  FIG. 1  as being adjacent to first end  25  of first cylinder  23 , pin  33  may conceivably be located anywhere along the outer surface  31  of first cylinder  23 , including, but not limited to, the approximate center of first cylinder  23 . Further, first cylinder  23  may be about 4 inches longer than second cylinder  35 , a length relative to second cylinder  35  which may permit a user to grasp cylinder  23  from either end  25  or end  27  (rather than from only one end as described above). To that end, variations of the pattern of groove  47  are possible, and will be described further supra, which would allow a user to extract cylinder  23  from either end of second cylinder  35  (where groove  47  is accessible from either end of cylinder  35 ) or which would force a user to move a centrally located pin such as pin  33  from a starting position midway between first and second ends  37  and  41  of second cylinder  35  toward first end  37  or toward second end  41  of cylinder  35  to seek a solution (where groove  47  is accessible from only one end of cylinder  35 ). Where pin  33  is located near the center of first cylinder  23  and the starting position of pin  33  is midway between first and second ends  37  and  41  of second cylinder  35 , it may be preferable to attach optional lanyard  48  midway between first and second ends  37  and  41  of second cylinder  35  to avoid indicating which direction of movement yields the solution. 
         [0045]    Where groove  47  is accessible from both ends of second cylinder  35 , puzzle  21  may more readily lend itself to speed contests and the like, and therefore may benefit from markings to distinguish one end from the other (each end marked with a different color or symbol, for example). The ability to distinguish one end from another may provide a common starting points for all players in a given contest and may also discourage players from cheating by improperly flipping the puzzle over and extracting the pin from the starting point as though it were the ending point (as opposed to properly moving the pin completely through the maze). Optional lanyard  48  may also be used to determine the whether first cylinder  23  has passed through second cylinder  35 . Although lanyard  48  is illustrated as being attached to outer surface  43  of second cylinder  35  adjacent to first end  37 , lanyard  48  may conceivably be attached anywhere on outer surface  43  of second cylinder  35  as long as the length of lanyard  48  is sufficient to allow first cylinder  23  to be passed completely through second cylinder  35 . 
         [0046]      FIG. 3  is a cross sectional view of puzzle  21  taken through pin  33  along line  3 - 3  of  FIG. 2  which illustrates a first pin/groove arrangement in which pin  33  may project from outer surface  31  of first cylinder  23  and may engage with groove  47  on inner surface  45  of second cylinder  35 . 
         [0047]      FIG. 4  cross-sectional view of puzzle  21  taken through pin  33  along line  3 - 3  of  FIG. 2  which illustrates a second pin/groove arrangement in which a pin  51  may project from inner surface  45  of second cylinder  35  and may engage with a groove  53  on outer surface  31  of first cylinder  23 . 
         [0048]      FIG. 5  is a cutaway perspective view of a second embodiment of the invention seen as puzzle  55 , which is similar to puzzle  21  of  FIGS. 1 and 2  except for modifications to second cylinder  35 , described as follows. In  FIG. 5 , second cylinder  35  is closed at second end  41  by end piece  57 . End piece  57  may be formed simultaneously with second cylinder  35  or may be formed separately as a cap or plug type closure. End piece  57  is adjacent a spring  61  which extends into an accommodation space  63  adjacent second end  41  of second cylinder  35 . Groove  47  (not shown in  FIG. 5 ) may or may not extend the full length of inner surface  45  of second cylinder  35 . 
         [0049]    A canister  65  may fit into accommodation space  63  such that when first cylinder  23  is advanced toward canister  65 , first end  25  of first cylinder  23  exerts force on canister  65 , which compresses spring  61  in turn. Groove  47  may preferably be designed so that moving pin  33  into a blind passage of groove  47  causes canister  65  to be trapped by first cylinder  23 . Spring  61  is shown between end piece  57  and canister  65 , but may conceivably be located between canister  65  and first end  25  of first cylinder  23 . 
         [0050]    Canister  65  is shown as having a lid  67  but may conceivably have any of a variety of accesses, including a hidden access. Compression of spring  61  by canister  65  when puzzle  55  is fully assembled may prevent canister  65  from shifting about inside second end  41  of second cylinder  35 , potentially helping to conceal its presence. Conversely, canister  65  may be removed from second cylinder  35  once groove  47  is successfully navigated so that first cylinder  23  may be removed. 
         [0051]    While  FIG. 5  illustrates puzzle  55  as a 2-cylinder puzzle, it is conceivable to incorporate canister  65  into a multi-cylinder puzzle having any number of cylinders. Canister  65  may be used to contain items such as candy or small prizes which can be offered as motivation or reward for successful navigation of the maze  47 , for instance. Additional uses for canister  65  are virtually unlimited: it may be used as a hiding place; it may be used to contain a gift or a note; or, it may used to contain a clue where, for example, an organized game may involve several hidden puzzles that must be found and worked in succession. 
         [0052]      FIG. 6  is a cutaway perspective view of a third embodiment of the invention seen as puzzle  71 , which is similar to puzzle  21  of  FIGS. 1 and 2  except for a added features as follows. Second end  27  of first cylinder  23  may include a large-diameter handle  73 , and second end  41  of second cylinder  35  may similarly include a large-diameter handle  75 . Second cylinder  35  may also include a pin  77  projection from outer surface  43  adjacent first end  37 . Handles  73  and  75  may preferably be approximately 2 inches in length, potentially increasing the overall length of first and second cylinders  23  and  35  by about 2 inches each. 
         [0053]    Puzzle  71  may further include a third cylinder  81  having a first end  83 , a second end  85 , an outer surface  87 , and an inner surface  91 . The length of cylinder  81  may preferably be about 12 inches to match the preferred length of the main portion of first and second cylinders  23  and  35 . Third cylinder  81  may include a groove  93  on its inner surface  91  and may have a diameter larger than that of second cylinder  35  which closely approximates the diameter of handles  73  and  75  of first and second cylinders  23  and  35 , respectively, to prevent any two adjacent cylinders (either  23  and  35  or  35  and  81 ) from being withdrawn as a pair without having worked both of pins  33  and  77  through grooves  47  and  77 , respectively, so that two independent solutions must be determined sequentially to some degree. The use of handles  73  and  75  requires each of grooves  47  and  77  to be navigated by each of pins  33  and  77 , respectively, before either first cylinder  23  or second cylinder  35  can be withdrawn from third cylinder  81 . 
         [0054]    To solve puzzle  71 , a user may extract first cylinder  23  from first end  37  of second cylinder  35  by manipulating first cylinder  23  to move pin  33  through groove  47 , and may subsequently extract second cylinder  35  from second end  85  of third cylinder  81  by manipulating second cylinder  35  to move pin  77  through groove  93 . Although handles  73  and  75  are illustrated at opposite ends of puzzle  71  in  FIG. 6 , it is conceivable that both handles could be located at the same end of puzzle  71 , in which case second cylinder  35  could be extracted from third cylinder  81  after first cylinder  23  is extracted from second cylinder  35  or could be extracted from third cylinder  81  with first cylinder  23  in tow, after which first cylinder  23  could then be extracted from second cylinder  35 . The components of puzzle  71  may also be attached to one another using lanyards such as optional lanyard  48  on puzzle  21  of  FIGS. 1 and 2 . 
         [0055]      FIG. 7  is a cross-sectional view of puzzle  71  taken through pin  77  along line  7 - 7  of  FIG. 6  which illustrates the first of many possible pin/groove arrangements. Although pins  33  and  77  are not illustrated as aligned with one another in  FIG. 6 ,  FIG. 7  depicts pins  33  and  77  as being aligned for clarity and ease of reference. Pin  33  may project from outer surface  31  of first cylinder  23 , either adjacent to first end  25  or second end  27  or midway between ends  25  and  27 , to engage with groove  47  on inner surface  45  of second cylinder  35 , and pin  77  may project from outer surface  43  of second cylinder  35  to engage with groove  93  on inner surface  91  of third cylinder  81 . 
         [0056]      FIG. 8  is a cross-sectional view of puzzle  71  taken through pin  77  along line  7 - 7  of  FIG. 6  which depicts pins  33  and  77  in alignment for clarity and illustrates a second pin/groove arrangement in which a pin  95  may extend from inner surface  45  of second cylinder  35  and may engage with a groove  97  on outer surface  31  of first cylinder  23 , and a pin  101  may extend from inner surface  91  of third cylinder  81  and may engage with a groove  103  on outer surface  43  of second cylinder  35 . 
         [0057]      FIG. 9  is a cross-sectional view of puzzle  71  taken through pin  77  along line  7 - 7  of  FIG. 6  which depicts pins  33  and  77  in alignment for clarity and illustrates a third pin/groove arrangement in which a pin  105  may extend from inner surface  45  of second cylinder  35  and may engage with a groove  107  on outer surface  31  of first cylinder  23 , and a pin  111  may extend from outer surface  43  of second cylinder  35  and may engage with a groove  113  on inner surface  91  of third cylinder  81 . 
         [0058]      FIG. 10  is a cross-sectional view of puzzle  71  taken through pin  77  along line  7 - 7  of  FIG. 6  which depicts pins  33  and  77  in alignment for clarity and illustrates a fourth pin/groove arrangement in which a pin  115  may extend from outer surface  31  of first cylinder  23  and may engage with a groove  117  on inner surface  45  of second cylinder  35 , and a pin  121  may extend from inner surface  91  of third cylinder  81  and may engage with a groove  123  on outer surface  43  of second cylinder  35 . In this configuration, it may be preferable for second cylinder  35  to have thicker walls to structurally support each of grooves  117  and  123  on each of inner surface  45  and outer surface  43 , respectively. 
         [0059]      FIG. 11  is a cross-sectional view of puzzle  71  taken through pin  77  along line  7 - 7  of  FIG. 6  which depicts pins  33  and  77  in alignment for clarity and illustrates a fifth pin/groove arrangement in which a pin  125  may extend from outer surface  31  of first cylinder  23  and may engage with a slot  117 , which extends completely through inner surface  45  of second cylinder  35  and through outer surface  43  as shown. A pin  131  may extend from inner surface  91  of third cylinder  81  and may also engage with slot  117 . In this configuration, the lengths of pins  125  and  131  may be short enough to allow both pins  125  and  131  to pass one another, or may be long enough to prevent them from passing one another to introduce a greater degree of difficulty. For example, maze patterns may be designed such that pins  125  and  131  may pass one another only where one of the pins  125  or  131  can be parked in a blind passage of slot  117  to allow the other of the pins  125  or  131  to pass. The level of difficulty for this particular configuration may be inversely proportional to the number of passable points built into a given maze pattern. 
         [0060]      FIG. 12  is a schematic layout of a first maze pattern for use with the present invention in which X represents a starting point and Y represents an ending point. Although the maze pattern in  FIG. 12  is illustrated as having a blind passage at X, the maze pattern could conceivably be open at X to allow exit from the maze. 
         [0061]    The solution to the maze of  FIG. 12  is illustrated in dashed line format. Letters A through D represent passages in the maze which may link together when the maze is applied to a circumferential surface. A pin (not illustrated) may preferably move along the dashed line from X to A 1  which links to A 2 , to D 1  which links to D 2 , and finally to Y. B 1  and C 1  link to blind passages B 2  and C 2 , respectively. 
         [0062]      FIG. 13  is a schematic layout of a second maze pattern in which a pin (not illustrated) may preferably move along the dashed line from X to A 1  which links to A 2 , to B 1  which links to B 2 , to C 1  which links to C 2 , to D 1  which links to D 2 , to E 1  which links to E 2 , to F 1  which links to F 2 , to G 1  which links to G 2 , to H 1  which links to H 2 , and finally to Y. J 1  links to blind passage J 2 . 
         [0063]      FIG. 14  is a schematic layout of a third maze pattern in which a pin (not illustrated) may preferably move along the dashed line from X to A 1  which links to A 2 , to B 1  which links to B 2 , to C 1  which links to C 2 , to D 1  which links to D 2 , to E 1  which links to E 2 , and finally to Y. With reference to  FIG. 5 , the  FIG. 14  maze may be ideal for use with puzzle  55  because it includes a blind passage at X in which a pin may be parked to help trap a canister (not illustrated). The maze of  FIG. 14  may generally also be used with any puzzle illustrated in  FIGS. 1 through 11 . Additionally, although the  FIG. 14  maze is illustrated as having a blind passage at X, it could conceivably be open at X to allow a pin to exit the maze, in which case a solution could be achieved from either direction (moving from X to Y or from Y to X). 
         [0064]      FIG. 15  is a schematic layout of a fourth maze pattern in which a pin (not illustrated) may preferably move along the dashed line from X to A 1  which is linked to A 2 , to B 1  which is linked to B 2 , and finally to Y. C 1  links to blind passage C 2 . 
         [0065]      FIG. 16  is a schematic layout of a fifth maze pattern which may be ideal for (but is not limited to) use with puzzles with a centrally located projecting pin such as that discussed in  FIG. 2  above. In the maze of  FIG. 16 , a pin (not illustrated) may optimally be initially situated at mid-maze starting point X and may preferably be moved along the dashed line from X to A 1  which links to A 2 , to C 1  which links to C 2 , and finally to Y. Alternatively, a pin may be moved from X to J 1  which links to J 2 , to K 1  which links to K 2 , to passage K 3  which links to a loop L in either direction. Entrance into and exit from loop L is only by way of passage K 3 , and movement within loop L is restricted to rotational movement. While loop L is illustrated in  FIG. 16  as being radially oriented and restricting translational movement, loop L may be any conceivable maze pattern which doubles back onto itself and is accessible by only a single passage. 
         [0066]    To successfully solve the maze of  FIG. 16  from a position anywhere between X and loop L, a user may move the pin toward X and subsequently toward Y as described above. F 1  and F 2  are blind passages which are placed to entice false starts in the X-to-L direction. F 3  is also a blind passage. 
         [0067]      FIG. 17  is a schematic layout of a sixth maze pattern in which a pin (not illustrated) may preferably move along the dashed line from X to E 1  which links to E 2 , and finally to Y. A 1 , B 1 , C 1 , and D 1  link to blind passages A 2 , B 2 , C 2 , and D 2 , respectively. 
         [0068]      FIG. 18  is a schematic layout of a seventh maze pattern in which a pin (not illustrated) may preferably move along the dashed line from X to A 1  which links to A 2 , to B 1  which links to B 2 , to E 1  which links to E 2 , and finally to Y. C 1  and D 1  link to blind passages C 2  and D 2 , respectively. 
         [0069]    The mazes of  FIGS. 17 and 18  may be used independently of one another or may be used together in multi-cylindrical, multi-maze puzzles such as puzzle  71  of  FIG. 6 , for example. Further, the mazes of  FIGS. 17 and 18  are optimal for use on opposing surfaces of the same cylinder, such as the alternative pin/groove arrangement described in  FIG. 10 , since they are designed to preserve the structural integrity of the cylinder in such an arrangement by traversing one another minimally. 
         [0070]    Maze patterns which may be used with puzzle embodiments described in  FIGS. 1 through 11  are not limited to those shown in  FIGS. 12 through 18 , which are merely representative. Further, although the maze patterns in  FIGS. 12 through 18  illustrate a single solution path between beginning and ending points, it is conceivable that a given maze pattern may have more than one solution path between beginning and ending points. It is also conceivable that maze patterns developed for the puzzle of the present invention may be numbered or even named to distinguish them from one another for separate sale or interchangeable use. 
         [0071]    Additionally, although maze patterns in  FIGS. 12 through 18  illustrate specific combinations of longitudinal turns in the X-Y direction and lateral or radial turns perpendicular to the X-Y direction, or diagonal turns which incorporate both lateral and longitudinal elements, the number of possible turn combinations may be limited by the length of the puzzle cylinders, the circumference of the cylinder surface bearing the maze pattern, and the pin size. 
         [0072]    Finally, although the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art.