Abstract:
A set of combined construction toy and marker bodies. Each marker ( 50 ) includes ball portions ( 58, 60 ) and socket portions ( 62, 64 ) that receive the ball portions ( 58, 60 ). The construction facilitates a pivoting, rotatable interconnection between markers. All of the markers ( 50 ) may also consist of an identical shape. Each marker ( 50 ) may further include a separable cap ( 54 ) that incorporates a ventilated end ( 132 ) to allow fluid passage therethrough, so as to provide an air passageway ( 130 ) through the cap ( 54 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a continuation of U.S. application Ser. No. 09/797495, filed on Mar. 1, 2001. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates generally to the field of elements which connect together, and more particularly concerns writing devices which connect together.  
         BACKGROUND OF THE INVENTION  
         [0003]    Drawing tools such as colored pencils, crayons, markers, and the like, satisfy creative and developmental needs of children. Construction toys, widely used by children as a playtime staple, can also be educational, and stimulate a child&#39;s imagination while satisfying a need for creative expression.  
           [0004]    It would be desirable for markers to be combined with construction elements, which can be used to create three-dimensional figures and models. Thus, two popular forms of children&#39;s self-expression could be combined to allow an easy, seamless transition between two-dimensional and three-dimensional modes of expression.  
           [0005]    The invention provides such a device. These and other advantages of the present invention, as well as other additional inventive features, will be apparent from the description of the invention provided herein.  
         SUMMARY OF THE INVENTION  
         [0006]    The invention provides for a set of markers which connect together and which may utilize a pivoting ball-and-socket connection between individual markers. In one embodiment, individual markers may include ball portions and socket portions disposed at both of their ends. The connections may then be formed by snapping a ball portion into a socket portion, resulting in a pivoting, rotatable connection.  
           [0007]    Each individual marker may consist of a body, an end plug, an ink reservoir, a writing nib, and a removable cap. In one embodiment, the cap includes at least one ball portion. The end plug of this embodiment is receivable within an open end of the marker body and includes at least one socket portion that receives a ball portion as described above. In other embodiments, the design of the cap and end plug allows for the connection of multiple markers at the end of each marker.  
           [0008]    The marker cap may also be ventilated so as to provide an air passageway through the cap in the event the cap becomes lodged in a child&#39;s throat.  
           [0009]    Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a perspective view of a plurality of markers linked together according to an embodiment of the present invention.  
         [0011]    [0011]FIG. 2 is an exploded side elevational view of an individual marker assembly.  
         [0012]    [0012]FIG. 3 is a side elevational view of an individual marker assembly.  
         [0013]    [0013]FIG. 4 is a sectional view of the individual marker assembly shown in FIG. 3.  
         [0014]    [0014]FIG. 5 is a perspective view of a ventilated marker cap, according to an embodiment of the present invention.  
         [0015]    [0015]FIG. 6 is a top plan view of the ventilated marker cap shown in FIG. 5.  
         [0016]    [0016]FIG. 7 is a sectional view of the ventilated marker cap shown in FIG. 5, taken along line  7 - 7  of FIG. 6.  
         [0017]    [0017]FIG. 8 is a bottom view of the ventilated marker cap shown in FIG. 5.  
         [0018]    [0018]FIG. 9 is a perspective view of a marker end plug according to the present invention.  
         [0019]    [0019]FIG. 10 is a side elevational view of the marker end plug shown in FIG. 9.  
         [0020]    [0020]FIG. 11 is a side view of the marker with the marker cap positioned on the end plug.  
         [0021]    [0021]FIG. 12 is a top view of two markers connected together.  
         [0022]    [0022]FIG. 13 is a side view of two markers connected together.  
         [0023]    [0023]FIG. 14 is a side view of two markers connected together.  
         [0024]    [0024]FIG. 15 is a side view of two markers connected together.  
         [0025]    [0025]FIG. 16 is a perspective view of a plurality of markers linked together according to another embodiment of the present invention.  
         [0026]    [0026]FIG. 17 is an exploded side elevational view of an individual marker assembly.  
         [0027]    [0027]FIG. 18 is a side elevational view of an individual marker assembly.  
         [0028]    [0028]FIG. 19 is a sectional view of the individual marker assembly shown in FIG. 18.  
         [0029]    [0029]FIG. 20 is a perspective view of a ventilated marker cap, according to an embodiment of the present invention.  
         [0030]    [0030]FIG. 21 is a top plan view of the ventilated marker cap shown in FIG. 20.  
         [0031]    [0031]FIG. 22 is a sectional view of the ventilated marker cap, taken along line  22 - 22  of FIG. 21.  
         [0032]    [0032]FIG. 23 is a bottom view of the ventilated marker cap shown in FIG. 20.  
         [0033]    [0033]FIG. 24 is a perspective view of a marker end plug.  
         [0034]    [0034]FIG. 25 is a side elevational view of the marker end plug shown in FIG. 24.  
         [0035]    [0035]FIG. 26 is a side view of two markers linked together according to another embodiment.  
         [0036]    [0036]FIG. 27 is a top view of the two markers shown in FIG. 26.  
         [0037]    [0037]FIG. 28 is a side view of the two markers shown in FIG. 26.  
         [0038]    [0038]FIG. 29 is a side view of the two markers shown in FIG. 26.  
         [0039]    [0039]FIG. 30 is a side view of the two markers shown in FIG. 26.  
         [0040]    [0040]FIG. 31 is a side view of the marker cap positioned on the end plug. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0041]    A plurality of connectable markers constructed in accordance with the teachings of the invention is illustrated in FIG. 1. According to the teachings of the invention, each marker  50  may include a body  52 , a cap  54 , and an end plug  56 . The caps  54  and end plugs  56  of each marker  50  may include mating connectors that facilitate flexible, rotatable interconnection between individual markers  50 .  
         [0042]    Referring further to FIG. 1, there is shown an illustrative embodiment of the invention wherein a plurality of markers, each including a cap  54  and an end plug  56 , are linked together. According to this embodiment, the connection between individual markers is made when a ball portion  58 ,  60 , attached to the cap  54  of one marker  50  is received within a socket portion  62 ,  64 , built into the end plug  56  of another. A ball-and-socket connection provides a flexible, rotatable arrangement that allows the construction of a wide range of three-dimensional figures, or simply the bundling of a group of markers together for storage and transport.  
         [0043]    In keeping with this embodiment of the invention, each marker  50  is a writing device. As is shown in FIG. 2, each individual marker includes a body  52 , a cap  54 , and an end plug  56 . In this embodiment, the body  52  includes a barrel  57  and a collet  59 . The body  52  includes an open end  102  and a drawing end  104 . The drawing end  104  receives a nib  106 , and the open end  102  of the body  52  receives an ink reservoir  108 . The nib  106  further includes a writing end  110  and a contacting end  112  that engages the reservoir  108 , thus creating a path for ink to flow from the reservoir  108  through the nib  106  when the writing end  110  contacts a writing surface.  
         [0044]    In this embodiment, the end plug  56  of the marker assembly  50  is received within the open end  102  of the marker body  52 . The end plug  56  seals the open end  102  of the marker body  52 , which contains the ink reservoir  108 . Referring to FIGS. 9 and 10, the end plug  56  includes annular ridges  114 ,  116  that engage the interior of the open end  102  of the marker body  52 , to secure and seal the end plug  56  within the marker body  52 . The marker body  52  is thus sealed, to prevent the ink in the reservoir  108  from evaporating.  
         [0045]    [0045]FIG. 2 also illustrates the end cap  54  of this embodiment, which receives the drawing end  104  of the marker body  52 . The cap  54  functions to protect the nib  106  and to prevent the marker ink from evaporating when the marker is not in use. As is more clearly seen in FIG. 7, the cap  54  includes an interior annular ring  120  that interlocks with a corresponding annular ring  122 , seen in FIG. 2, on the exterior of the drawing end  104  of the marker body  52 . The engagement of the locking rings  120 ,  122  secures the cap  54  to the drawing end  104  of the marker body  52  when the marker assembly  50  is not in use.  
         [0046]    [0046]FIG. 3 is a side view of a marker assembly  50 , and illustrates the interrelationships among the assembled marker components. FIG. 4 is a sectional view of the individual marker  50  of FIG. 3. The cap  54  receives and seals the drawing end  104  of the marker body. The end plug  56  is received within the open end  102  of the marker body  52 , and seals the open  102  end of the marker body  52 . The cap  54  and end plug  56  prevent the ink reservoir  108  from drying out through evaporation when the marker is not in use.  
         [0047]    As is seen in FIGS. 5 and 7, the cap  54  includes an outer cylinder  124 , ball portions  58 ,  60 , an open end  126 , a vented end  128 , and an inner cap  130 . The ball portions  58 ,  60  are connected to the vented end  128  of the cap  54  by means of short pegs  134 ,  136 . In this embodiment, the pegs  134 ,  136  are illustrated as cylindrically shaped. However, their shapes may vary, and are they are not limited to their configuration in this illustrative embodiment.  
         [0048]    In this illustrative embodiment, the cap  54  may also be vented to reduce its potential choking hazard to children. If the vented cap  54  were to lodge in a child&#39;s throat, it would allow the child to safely breathe until removed. The venting may be achieved by means of a ventilation passage  138 , shown in FIGS.  6 - 8 . This passage  138  consists of the space between an inner cap  130 , with an open end  132 , and the outer cylinder  124 , resulting from their connection in a coaxial, spaced-apart relationship by bridge portions  140 ,  142 ,  146 ,  148 , which extend from the interior of the cap outer cylinder  124  to the exterior of the inner cap  130 . FIG. 7, a sectional view along line  7 - 7  of FIG. 6, illustrates the connection of the inner cap  130  to the outer cylinder  124  by bridge portion  140 .  
         [0049]    In this illustrative embodiment, the inner cap  130  receives the nib  106 , as the cap  54  receives the drawing end  104  of the marker body  52 . This construction allows the cap  54  to protect the nib  106  and to prevent the ink from evaporating. In addition, this construction also provides a passageway for air between the inner cap  130  and outer cylinder  124 , such that a child may continue breathing in the event that the cap  54  becomes lodged in the child&#39;s throat through accidental ingestion. Further, FIG. 7 illustrates an annular ring  120  disposed on the interior of the outer cylinder  124 , spaced apart from the open end  126  of the cap  54 . This annular ring  120  secures the cap  54  to the marker body  52  by interlocking with the annular ring  122 , shown in FIG. 2, on the marker body  52  when the marker is not in use.  
         [0050]    The illustrative embodiment also includes an end plug  56 , as illustrated in FIGS. 9 and 10. The end plug  56  includes a tubular end  150  that is received within the open end  102  of the marker body  52 . The annular ridges  114 ,  116  on the end plug  56  engage the interior of the tubular marker body  52  so as to secure the end plug  56  in place, thus sealing the open end  102  and rendering the end plug  56  difficult to remove.  
         [0051]    The end plug  56  of this embodiment also includes two diametrically opposed sockets  62 ,  64 . Each socket  62 ,  64  is defined by prongs  66 ,  68 ,  70 ,  72  and  74 ,  76 ,  78 ,  80 , respectively, and each socket  62 ,  64  is configured to receive a ball portion  58 ,  60 . Each prong  66 ,  68 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80  of this particular embodiment includes a lug  86 ,  88 ,  90 ,  92 ,  94 ,  96 ,  98 ,  100 , respectively, that protrudes toward the interior of the socket  62 ,  64  formed by its associated prong. The lugs  86 ,  88 ,  90 ,  92 ,  94 ,  96 ,  98 ,  100  partially surround, and thus rotatably lock a ball portion  58 ,  60  within the socket, as is clearly seen in FIG. 1. The prongs  66 ,  68 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80  are spaced apart from one another in order to allow rotation and relative motion of coupled markers as the short pegs  134 ,  136  are rotated into the spaces between adjacent prongs. In the embodiment shown, the ball and socket connection offers flexibility because the spaces between the prongs  66 ,  68 ,  70 ,  72 ,  74 ,  76 ,  78 ,  80  allow the ball connecting pegs  134 ,  136  to be rotated past the ball retaining lugs  86 ,  88 ,  90 ,  92 ,  94 ,  96 ,  98 ,  100  of the sockets  62 ,  64  as the marker is rotated.  
         [0052]    In this embodiment, the exterior of the socket  62 ,  64  is circular in cross-section. In other embodiments, the exterior of the socket may have other cross-sections or configurations.  
         [0053]    According to the teachings of the invention, the actual number of sockets disposed on each end plug  56  is not limited to two, as described in this illustrative embodiment. Any number of sockets, which may ultimately be limited by production methods, may be disposed on each end plug  56 . For example, the end plug may include one, three, four, five, or more sockets. Furthermore, the ball portions  58 ,  60  and sockets  62 ,  64  are not limited to the configuration described in this embodiment. The ball portions  58 ,  60  may also be disposed on the end plug  56 , and the sockets  62 ,  64  may be disposed on a cap  54 . Ball portions  58 ,  60  and sockets  62 ,  64  may also be disposed in various symmetrical or asymmetrical orientations relative to each other. In another alternative embodiment, each end plug  56  or cap  54  may include both ball  58 ,  60  and socket  62 ,  64  portions.  
         [0054]    Similarly, the number of prongs or lugs defining each socket on the end plug of the illustrative embodiment is in no way meant to limit the scope or spirit of the invention. Any number of prongs or lugs can be incorporated, while still keeping within the scope of the invention. For example, each socket may include three, five, six, or more prongs or lugs.  
         [0055]    As is seen in FIGS. 9 and 10, the end plug  56  of this embodiment also includes an annulet  152  that is diametrically opposed to and coaxial with the tubular end  150  of the end plug  56 . The raised annulet  152  is sized so as to be slidably receivable within the open end  126  of cap  54  as shown in FIG.,  11 . Friction between the annulet  152  and the cap  54  retains the cap  54  in an easily accessible location when the marker  50  is used for writing or drawing. The annulet  152  is also configured to allow easy engagement and disengagement of cap  54 .  
         [0056]    FIGS.  12 - 15  show views of two markers  50 ,  51  connected together in various positions. The markers have an X axis  160 , a Y axis  162 , and a vertical Z axis  164 . The Y axis  162  is perpendicular to the X axis  160 . The vertical Z axis  164  is perpendicular to the X axis  160  and the vertical Z axis  164  is perpendicular to the Y axis  162 .  
         [0057]    Referring to FIG. 12, the markers  50 ,  51  are shown in a top view. The marker  51  is able to move in a range  168  of 0 to 180 degrees around the Z axis  164  relative to the marker  50 . Referring to FIG. 13, the markers  50 ,  51  are shown in a side view. The marker  51  is able to move in a range  170  of 0 to 360 degrees around the Y axis  162  relative to marker  50 . Referring to FIG. 14, the marker  51  is able to move in a range  172  of 0 to 50 degrees around the X axis  160  (in the Y-Z plane). Referring to FIG. 15, the marker  51  is able to move in a range  174  of 0 to 70 degrees around the X axis  160  (in the Y-Z plane).  
         [0058]    Another embodiment of connectable markers constructed in accordance with the teachings of the invention is illustrated in FIG. 16. According to the teachings of the invention, each marker  250  may include a body  252 , a cap  254 , and an end plug  256 . The caps  254  and end plugs  256  of each marker  250  may include mating connectors that facilitate flexible, rotatable interconnection between individual markers  250 .  
         [0059]    Referring further to FIG. 16, there is shown an illustrative embodiment of the invention wherein a plurality of markers, each including a cap  254  and an end plug  256 , are linked together. According to this embodiment, the connection between individual markers is made when a ball portion  258 ,  260 , attached to the cap  254  of one marker  250  is received within a socket portion  262 ,  264 , built into the end plug  256  of another. A ball-and-socket connection provides a flexible, rotatable arrangement that allows the construction of a wide range of three-dimensional figures, or simply the bundling of a group of markers together for storage and transport.  
         [0060]    In keeping with this embodiment of the invention, each marker  250  is a writing device. As is shown in FIG. 17, each individual marker includes a body  252 , a cap  254 , and an end plug  256 . The body  252  includes an open end  302  and a drawing end  304 . The drawing end  304  receives a nib  306 , and the open end  302  of the body  252  receives an ink reservoir  308 . The nib  306  further includes a writing end  310  and a contacting end  312  that engages the reservoir  308 , thus creating a path for ink to flow from the reservoir  308  through the nib  306  when the writing end  310  contacts a writing surface.  
         [0061]    In this embodiment, the end plug  256  of the marker assembly  250  is received within the open end  302  of the marker body  252 . The end plug  256  seals the open end  302  of the marker body  252 , which contains the ink reservoir  308 . Referring to FIGS. 24 and 25, the end plug  256  includes annular ridges  314 ,  316 ,  318  that engage the interior of the open end  302  of the marker body  252 , to secure and seal the end plug  256  within the marker body  252 . The marker body  252  is thus sealed, to prevent the ink in the reservoir  308  from evaporating.  
         [0062]    [0062]FIG. 17 also illustrates the end cap  254  of this embodiment, which receives the drawing end  304  of the marker body  252 . The cap  254  functions to protect the nib  306  and to prevent the marker ink from evaporating when the marker is not in use. As is more clearly seen in FIG. 22, the cap  254  includes an interior annular ring  120  that interlocks with a corresponding annular ring  322 , seen in FIG. 17, on the exterior of the drawing end  304  of the marker body  252 . The engagement of the locking rings  320 ,  322  secures the cap  254  to the drawing end  304  of the marker body  252  when the marker assembly  250  is not in use.  
         [0063]    [0063]FIG. 18 is a side view of a marker assembly  250 , and illustrates the interrelationships among the assembled marker components. FIG. 19 is a sectional view of the individual marker  250  of FIG. 18. The cap  254  receives and seals the drawing end  304  of the marker body. The end plug  256  is received within the open end  302  of the marker body  252 , and seals the open  302  end of the marker body  252 . The cap  254  and end plug  256  prevent the ink reservoir  308  from drying out through evaporation when the marker is not in use.  
         [0064]    As is seen in FIGS. 20 and 22, the cap  254  includes an outer cylinder  324 , ball portions  258 ,  260 , an open end  326 , a vented end  328 , and an inner cap  330 . The ball portions  258 ,  260  are connected to the vented end  328  of the cap  254  by means of short pegs  334 ,  336 . In this embodiment, the pegs  334 ,  336  are illustrated as cylindrically shaped. However, their shapes may vary, and are they are not limited to their configuration in this illustrative embodiment.  
         [0065]    In this illustrative embodiment, the cap  254  may also be vented to reduce its potential choking hazard to children. If the vented cap  254  were to lodge in a child&#39;s throat, it would allow the child to safely breathe until removed. The venting may be achieved by means of a ventilation passage  338 , shown in FIGS.  21 - 23 . This passage  338  consists of the space between an inner cap  330 , with an open end  332 , and the outer cylinder  324 , resulting from their connection in a coaxial, spaced-apart relationship by bridge portions  340 ,  342 ,  346 ,  348 , which extend from the interior of the cap outer cylinder  324  to the exterior of the inner cap  330 . FIG. 22, a sectional view along line  22 - 22  of FIG. 21, illustrates the connection of the inner cap  330  to the outer cylinder  324  by bridge portion  340 .  
         [0066]    In this illustrative embodiment, the inner cap  330  receives the nib  306 , as the cap  254  receives the drawing end  304  of the marker body  252 . This construction allows the cap  254  to protect the nib  306  and to prevent the ink from evaporating. In addition, this construction also provides a passageway for air between the inner cap  330  and outer cylinder  324 , such that a child may continue breathing in the event that the cap  254  becomes lodged in the child&#39;s throat through accidental ingestion. Further, FIG. 22 illustrates an annular ring  320  disposed on the interior of the outer cylinder  324 , spaced apart from the open end  326  of the cap  254 . This annular ring  320  secures the cap  254  to the marker body  252  by interlocking with the annular ring  322 , shown in FIG. 17, on the marker body  252  when the marker is not in use.  
         [0067]    The illustrative embodiment also includes an end plug  256 , as illustrated in FIGS. 24 and 25. The end plug  256  includes a tubular end  350  that is received within the open end  302  of the marker body  252 . The annular ridges  314 ,  316 ,  318  on the end plug  256  engage the interior of the tubular marker body  252  so as to secure the end plug  256  in place, thus sealing the open end  302  and rendering the end plug  256  difficult to remove.  
         [0068]    The end plug  256  of this embodiment also includes two diametrically opposed sockets  262 ,  264 . Each socket  262 ,  264  is defined by prongs  266 ,  268 ,  270 ,  272  and  274 ,  276 ,  278 ,  280 , respectively, and each socket  262 ,  264  is configured to receive a ball portion  258 ,  260 . Each prong  266 ,  268 ,  270 ,  272 ,  274 ,  276 ,  278 ,  280  of this particular embodiment includes a lug  286 ,  288 ,  290 ,  292 ,  294 ,  296 ,  298 ,  300 , respectively, that protrudes toward the interior of the socket  262 ,  264  formed by its associated prong. The lugs  286 ,  288 ,  290 ,  292 ,  294 ,  296 ,  298 ,  300  partially surround, and thus rotatably lock a ball portion  258 ,  260  within the socket, as is clearly seen in FIG. 16. The prongs  266 ,  268 ,  270 ,  272 ,  274 ,  276 ,  278 ,  280  are spaced apart from one another in order to allow rotation and relative motion of coupled markers as the short pegs  334 ,  336  are rotated into the spaces between adjacent prongs. In the embodiment shown, the ball-and-socket connection offers improved flexibility because the spaces between the prongs  266 ,  268 ,  270 ,  272 ,  274 ,  276 ,  278 ,  280  allow the ball connecting pegs  334 ,  336  to be rotated past the ball retaining lugs  286 ,  288 ,  290 ,  292 ,  294 ,  296 ,  298 ,  400  of the sockets  262 ,  264  as the marker is rotated.  
         [0069]    In this embodiment, the exterior of the socket  262 ,  264  is square in cross-section. In other embodiments, the exterior of the socket may have other cross-sections or configurations.  
         [0070]    According to the teachings of the invention, the actual number of sockets disposed on each end plug  256  is not limited to two, as described in this illustrative embodiment. Any number of sockets, which may ultimately be limited by production methods, may be disposed on each end plug  256 . For example, the end plug may include one, three, four, five, or more sockets. Furthermore, the ball portions  258 ,  260  and sockets  262 ,  264  are not limited to the configuration described in this embodiment. The ball portions  258 ,  260  may also be disposed on the end plug  256 , and the sockets  262 ,  264  may be disposed on a cap  254 . Ball portions  258 ,  260  and sockets  262 ,  264  may also be disposed in various symmetrical or asymmetrical orientations relative to each other. In another alternative embodiment, each end plug  256  or cap  254  may include both ball  258 ,  260  and socket  262 ,  264  portions.  
         [0071]    Similarly, the number of prongs or lugs defining each socket on the end plug of the illustrative embodiment is in no way meant to limit the scope or spirit of the invention. Any number of prongs or lugs can be incorporated, while still keeping within the scope of the invention. For example, each socket may include three, five, six, or more prongs or lugs.  
         [0072]    As is seen in FIGS. 24 and 25, the end plug  256  of this embodiment also includes a raised annulet  352  that is diametrically opposed to and coaxial with the tubular end  350  of the end plug  256 . The raised annulet  352  is sized so as to be slidably receivable within the open end  326  of cap  254 . Friction between the annulet  352  and the cap  254  retains the cap  254  in an easily accessible location when the marker  250  is used for writing or drawing. The annulet  352  is also configured to allow easy engagement and disengagement of cap  254 .  
         [0073]    Another embodiment of the invention is shown in FIGS.  26 - 31 . The marker  450  includes a body  452 , a cap  454  and an end plug  456 . The body  452 , the cap  454 , and the other components (except for the end plug  456 ) are similar to the components in the marker  50 . In this embodiment, the end plug  456  has a socket  462 . The socket  462  is configured to receive a ball portion  458 ,  460 . The socket  462  includes prongs  466 ,  468 . In this embodiment, the prongs  466 ,  468  have a circular configuration. In addition, the prongs  466 ,  468 , may have lugs  486 ,  488  that protrude toward the interior of the socket  462  formed by its associated prong. The lugs  486 ,  488  partially surround, and thus rotatably lock a ball portion  458 ,  460  within the socket, as shown in FIGS.  26 - 30 . The prongs  466 ,  468  are spaced apart from one another in order to allow rotation and relative motion of coupled markers as the short pegs  534 ,  536  are rotated into the space between the prongs. In this embodiment, the ball and socket connection offers flexibility because the space between the prongs  466 ,  468  allow the balls  458 ,  460  to be rotated as the marker is rotated.  
         [0074]    In addition, the end plug  456  may include an anti-roll feature. An anti-roll feature prevents the marker  450  from rolling off of a flat surface, such as a desk. In one embodiment, the anti-roll feature may include two arcs  472 ,  474  on the exterior of the end plug  456  as shown in FIG. 27. Thus, if the user were to place the marker  450  without the cap  454  on a flat surface, the arcs  472 ,  474  would prevent the marker from rolling. In other embodiments, the anti-roll feature may be a flat area on the end plug and/or body, or may be other shapes or configurations. In addition, the marker may include any number and/or combination of anti-roll features. For example, the marker may include: one arc; three arcs; four or more arcs; one or more arcs and one or more flat areas; two flat areas; three flat areas; or four or more flat areas.  
         [0075]    FIGS.  27 - 30  show views of two markers  450 ,  451  connected together in various positions. The markers have an X axis  160 , a Y axis  162 , and a vertical Z axis  164 . The Y axis  162  is perpendicular to the X axis  160 . The vertical Z axis  164  is perpendicular to the X axis  160  and the vertical Z axis  164  is perpendicular to the Y axis  162 .  
         [0076]    Referring to FIG. 27, the markers  450 ,  451  are shown in a top view. The marker  451  is able to move in a range  568  of 0 to 360 degrees around the Z axis  164  relative to the marker  450 . Referring to FIG. 28, the markers  450 ,  451  are shown in a side view. The marker  451  is able to move in a range  570  of 0 to 360 degrees around the Y axis  162  relative to marker  450 . Referring to FIG. 29, the marker  451  is able to move in a range  572  of 0 to 35 degrees around the X axis  160  (in the Y-Z plane). Referring to FIG. 30, the marker  451  is able to move in a range  574  of 0 to 35 degrees around the X axis  160  (in the Y-Z plane). Referring to FIG. 31, the cap  454  may be positioned on the end plug  456  for storage during use of the marker  450 .  
         [0077]    Thus, the invention provides markers integrated with a construction system that allow a child to sketch a figure that she will later build using the construction toys. Conversely, the integrated markers allow a child to immediately sketch or draw a three-dimensional figure that she has built using the construction system. Combining markers with a construction toy allows a child to seamlessly integrate two-dimensional creative ideas with a spatial mode of construction and expression, and is thus desirable as an educational toy.  
         [0078]    Additionally, integrating markers with the individual bodies of a construction system allows the markers to be linked together for storage or transit, thus eliminating the need for an additional case. It is further desirable for the construction bodies/markers to include integrated connection means such that no dedicated connectors are needed to link the markers. An integrated connection means also allows for various modes of interconnection among markers, such as rotatable connections, multiple element connections at one connection point, and the like.  
         [0079]    Connectable markers are particularly desirable when a flexible, versatile connection means is included. For example, a flexible ball-and-socket connection has inherently more degrees of freedom than a linear or otherwise fixed connection means. This type of connection facilitates a large number of possible shapes and connection orientations. The increased versatility affords a child greater freedom of expression.  
         [0080]    It is further desirable for the smaller components of a marker/construction system to be rendered safe for small children by means that reduce the choking hazard posed by such smaller components.  
         [0081]    A marker is merely an exemplary embodiment of this invention, and as such, does not limit the scope of the invention. The invention may be practiced with other types of writing devices such as pens, colored pencils, and crayons. In another embodiment, each writing instrument may include a plurality of shaft-like ends that facilitate coupling of separate elements. Further, each end of any embodiment of the invention may include a combination of ball and socket portions, or each end may only contain either ball portions or socket portions, without deviating from the scope or spirit of the invention.  
         [0082]    Moreover, the invention is not limited to a writing device. It can also be embodied simply as a non-drawing toy construction set including a plurality of uniformly shaped, connectable elements.  
         [0083]    While particular embodiments of the invention have been shown, it will be understood, of course, that the invention is not limited thereto. On the contrary, we intend to cover all alternatives, modifications and equivalents as may be included within the scope and spirit of the invention as defined by the appended claims.