the invention is particularly applicable to a toy and writing accessory that includes a plurality of structural elements or members that each are configured with complementary connector features as described below . the connector features allows the structural elements to be assembled in a writing - functional configuration when the toy is used as a writing instrument . additionally , a plurality of the structural elements can be re - assembled in a multitude of non - writing configurations to form a 3 - dimensional toy , figure , building etc . as described below . in this context , it will be appreciated that a modular assembly in accordance with the invention can have a range in utility from being a dedicated writing instrument to a being a “ toy ” with features for various play applications . further , the modular assembly can be a combination functional writing instrument and a toy assembly , all of which assemblies are within the scope of the invention . fig1 is an illustration of one embodiment of a combination modular toy and writing accessory 100 in accordance with the invention . the modular toy or pen apparatus as depicted in the exploded view of fig2 reveals that the pen of fig1 comprises an assembled set of exemplary snap - fit structural elements 110 , 112 and 114 that further includes a writing element or cartridge indicated at 115 . by the term ‘ snap - fit ’, it is meant that the fit of any complementary connector features can be an interference fit , a friction fit , a sliding fit or a fit wherein a connector component is slightly deformable for flexible snapping into place with a cooperating structural feature . the writing element 115 in this embodiment comprises a ball - point pen but the writing element can consist of any ink marker , graphite marker , crayon marker , eraser or the like . in the exploded view of fig2 , it can be seen that structural element 110 comprises a barrel - like body extending about longitudinal axis 120 with body walls surrounding passageway 122 within the element . an enlarged view structural element 110 is provided in fig3 . as can be seen in fig3 , structural element 110 includes body ends 124 a and 124 b that comprise a “ projecting ” connector feature indicated at 125 that is adapted to be engaged by a “ receiving ” connector feature of structural element 112 when assembled ( see fig2 and 4 ). the structural element 110 further includes at least one “ receiving ” connector feature 130 on a side of the element for receiving a “ projecting ” connector feature of another structural element . the body ends 124 a and 124 b of structural element 110 further include a groove 132 for cooperating with a complementary feature of element 112 described below . in general , the structural elements typically have an extending medial strut portion extending between first and second ends . further , the elements include one or more “ nodal ” connector features on at least one end or medial portion of such a structural element . by the term ‘ nodal ’, it is meant that the connection between structural elements comprises a node wherein the axes of the elements can be oriented at different relative angles and / or rotational angles about the connection . now referring to the exploded view of fig2 and fig4 , structural element 112 comprises another “ one - half ” barrel body extending about longitudinal axis 120 ′ that can be connected with another similar structural element to form a “ receiving ” feature to snap - fit to form a barrel - like shape and thereby grip and receive an end of structural element 110 . the snap - fit assembly of first and second elements 112 is enabled by male and female snap - fit features indicated at 136 . structural element 112 carries a circumferential rib 138 that cooperates with groove 132 in structural element 110 . further , structural element 112 includes a “ receiving ” connector feature 130 for receiving a “ projecting ” connector feature 145 such as in structural element 114 . referring now to fig2 and 5 , structural element 114 comprises another body extending relative to axis 120 ″ and having first and second body end portions 148 a and 148 b that have snap - fit projecting features 145 that project from the body perpendicular to axis 120 ″. the projecting features 145 are dimensioned to snap - fit into receiving features 130 of structural elements 110 and 112 . as can be seen in fig1 and 2 , these structure elements can be connected in multiple arrangements to provide the elongated barrel of a writing instrument . the views of fig1 , 2 and 4 illustrate that structural element 114 further includes part - circumferential body wings 155 that are dimensioned to engage the outer surface of another structural element when connected in a longitudinal orientation , that is with the axes 120 , 120 ′ and 120 ″ all in alignment . in one embodiment as shown in fig1 and 2 , the apparatus further includes a connectable proximal pen body 160 and distal pen body 162 that each can be snap - fit to ends of an assembled pen barrel to thereby capture writing element 115 therein ( e . g ., a ball - point ink cartridge ). a snap - fit pocket clip 164 with a single projecting feature 165 also is shown in fig1 and 2 to make the toy assembly into a fully functional writing instrument . in one embodiment shown in fig2 , the proximal and distal pen bodies 160 and 162 can further include spring 166 and an actuation mechanisms as well known in the art to provide a push button retractable ball - point pen fig6 depicts another embodiment in which a delivery tube component 170 is provided as packaging for an assembly of structural elements 110 , 112 , 114 , 115 , 160 and 162 that are either assembled as a pen or that can be assembled into a pen . in addition , the end - caps 175 of tube component 170 comprise toy structural elements as well , and more particularly are configured as toy ‘ wheels ’ with each having a connector portion such as projecting element 180 that can be snap - fit into a receiving connector feature 130 of another structural element . it should be appreciated end - cap ‘ wheels ’ 175 can have either or both ‘ projecting ’ and ‘ receiving ’ connector features as described above to allow coupling to complementary features at the side or end of any other structure elements , or the end - cap ‘ wheels ’ can couple about their axles one to another to provide tandem toy wheel elements . further , the toy wheels can be rotatable about an axle portion or the element that comprises a projecting and / or receiving feature thereof that is capable of connection with a complementary feature of another structural element . further , the delivery tube component 170 can be connected at its end to extend from a wheel 175 that is connected to another assembly , for example to provide an elongate element such as a rotating helicopter blade ( not shown ). further , the delivery tube 170 can further include projecting and / or receiving features ( not shown ) along its side to allow its connection to a toy in a plurality of configurations . now turning to fig7 , one embodiment of a toy ‘ buggy ’ vehicle or landcraft 200 is shown that is assembled from exemplary structural elements 110 , 112 and 114 as described above . in fig7 and the exploded view of fig8 , it can be seen that a plurality of the structural elements can be assembled into a vehicle chassis assembly 205 with four wheel ( end - cap ) elements 175 . further , as can be seen in fig8 , the vehicle body assembly 210 and windscreen assembly 215 are provided by coupling together various arrangements of structural elements 110 , 112 and 114 . it can be appreciated that fig7 and 8 illustrate only one of a practically infinite number of toys that can be assembled from the structural elements of the invention . a plurality of such structural elements can be connected together to provide any desired three - dimensional geometric shape , such as resembling one or more portions of a spacecraft , aircraft , landcraft , watercraft , or submarine . any assembled toy may be a static form or a non - static such as a land - or aircraft with rotating wheels or blades . the structural elements also can connected together to provide geometric shapes resembling buildings , constructions , castles , pyramids , geographic and topographic features , planetary arrangements and the like . the structural elements also can connected together to provide geometric shapes resembling torsos , legs , arms or heads of a human , an animal or fantasy being , free - form structures , stick - form molecules , geometric forms or even wearable ornaments . as shown in fig2 , 7 , 8 and 9 a , it can be seen that the cross - sections of complementary connection comprising ‘ receiving ’ features 130 and projecting features 145 are round thus allowing for freedom of rotation between the structural elements about the connection . in another embodiment , referring to fig9 a and 9b , it can be seen that the cross - sections of complementary ‘ receiving ’ features 130 ′ and snap - fit projecting features 145 ′ can be non - round and provided with at least one set of complementary facets 220 and 222 for allowing a ‘ click - stop ’ rotational orientation of one structural element relative to another . another embodiment of a structural element 240 is shown in fig1 a and 10b , wherein a medial portion of the element comprised a flexible body portion 244 . fig1 c illustrates that the ends of flexible element 240 are configured for snap fit into a receiving features of assembled elements 112 . fig1 a illustrates a flexible plastic bellows , but it should be appreciated the flexible body portion 244 can comprise a rubber or foam material , a helical spring or the like . fig1 illustrates an assembly of structural elements 110 , 112 , 114 and 175 into a tank 300 . fig1 illustrates an assembly of structural elements 110 , 112 , 114 and 175 into another embodiment of a vehicle 310 . in another embodiment ( not shown ), the connector ‘ receiving ’ and projecting features can include complementary magnetic structures ( preferably neodymium magnets ) rather than snap - fit moldable plastic features . the structural elements that include flexible body portions enables the construction of toys with a truly infinite number of possible geometric shapes so there is no limit but the child &# 39 ; s imagination as to what can be constructed using the inventive system . the modular structural elements and system are adapted to foster creative expression , and to allow a child to created custom toys and playscapes . the structural elements are not limited to any particular size , elongate dimensions or shape . the structural elements are preferably made of a moldable plastic that is clear , colored or translucent , for example an abs plastic . it should be appreciated that structural elements also can be any moldable foam , rubber or metal as is know in the art . in one embodiment as shown in fig5 , the surfaces of a structural element can include bumps or facets 250 for contacting a surface feature of another structural element to provide a particular orientation . while the foregoing has been with reference to a particular embodiment of the invention , the foregoing description is that of certain features , aspects and advantages of the present invention , to which various changes and modifications can be made without departing from the spirit and scope of the present invention . thus , for example , those skilled in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one advantage or a group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein . in addition , while a number of variations of the invention have been shown and described in detail , other modifications and methods of use , which are within the scope of this invention , will be readily apparent to those of skill in the art based upon this disclosure . it is contemplated that various combinations or subcombinations of these specific features and aspects of embodiments may be made and still fall within the scope of the invention . accordingly , it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the discussed bone treatment systems and methods .
a modular combination toy and desktop writing accessory apparatus comprising a plurality of structural elements each having at least one nodal connector portion to which a complementary connector portion of another structural , element can be coupled . the structural elements can be assembled into a barrel - like form that is configured with a passageway for carrying a writing component of the invention . the writing component can be a pen , pencil , marker , crayon , eraser or the like . the modular combination toy and writing instrument has multiple functions in playtime as well as in everyday desk - bound activities .