Background of the Invention In general, the user makes a built-up structure in a desired shape by assembling a plurality of parts such as blocks, and structures of various forms are used according to the kind of block and the method of assembly. Especially for children, blocks are frequently used to make built-up toys.

The building blocks take many different forms, and some of these forms have become extremely well known in association with their respective trademarks, e. g. LEGO, DUPLO, MINIBRIX, etc.. The blocks employ various interconnection means to permit them to be snapped together in a fixed relationship in order to build structures.

It is believed that the most pertinent such toy building blocks are disclosed in U. S. Pat. No. 5,527,201, patented Jun. 18, 1996, by the present inventor, Paul T. Maddock. That patent provided a toy construction kit with interconnecting holding means, and included a

plurality of building pieces of various configurations, including building pieces each having six faces, each one of the six faces having interconnection means which was configured for direct connection to complementary interconnection means on other building pieces. The interconnection means in at least one of the faces included an aperture defined therein which was particularly sized and shaped to receive a connector member in the kit which was either a planar, essentially quadrangular cross-section elongate element or a planar, essentially quadrangular cross-section tongue integral with and extending from another building piece.

U. S. Pat. No. 4,423,465, patented Dec. 27,1983, by W. Teng-Ching et al. That patent taught cubic blocks which were used to assemble an electronic circuit. The structure of these blocks included a pair of dovetail-shaped recesses in one pair of its outer opposite surfaces and a pair of dovetail-shaped projections on another pair of its outer opposite surfaces, to provide four block-engaging surfaces or four joints. A plurality of blocks could thereby be put together by bringing a recess into union with a projection.

Many prior art building block toys have many obvious attractions and should not be criticized. However, a disadvantage of such block- built toys is that they cannot be practically used because of their low durability, although they can be embodied in a variety of shapes. For example, blocks can be built in the shape of a bicycle or shopping cart, but if a child rides the bicycle or one puts things in the shopping cart, the

blocks will be separated from it due to the low durability and it cannot be used as suited to its shape.

In addition, since most of conventional built-up toys can be made only in one or two pre-determined shapes, they cannot be made in the shape as desired by the user and have a low degree of freedom.

Summary of the Invention Accordingly, an object of the present invention to provide a built-up multipurpose structure assembly that can be easily embodied into a variety of practically usable articles such as skis, rocking chairs, shopping carts and boats as well as single-seat or multi-seat bicycles, since the structures made from a plurality of assembly parts have a given shape and durability.

To achieve the above objects, one aspect of the present invention is as follows; a built-up multipurpose structure assembly comprises a mainframe constituting the main body, and a plurality of frame stays connected to one end or opposite ends of the mainframe in such a mountable and dismountable manner that it is possible to run and roll in all positions.

In addition, the built-up multipurpose structure assembly comprise: a mainframe which is arranged lengthwise; the first column on which a handlebar is mounted; the second column fixed to one end of said mainframe by interposing a column joint, and is connected to the lower

end of said first column; a pair of first wheels rotatably installed at the lower end of said second column; a pair of second wheels rotatably installed one end of said mainframe; and a seat mounted on said mainframe by means of joints.

Further, the built-up multipurpose structure assembly for forming rocking chairs comprise: a mainframe which is arranged lengthwise; sub frames which are transversely connected opposite ends of said mainframe; a pair of rocking carriers which are connected opposite ends portions of the first axis inserted in said sub frames by means of joint for rocking motion in place; and a seat plate mounted on said mainframe by means of joint.

And, the built-up multipurpose structure assembly for forming a bicycle comprise: a mainframe which is arranged lengthwise; a connecting frame connected to one end of said mainframe; the first column on which handlebars are mounted; the second column fixed to one end of said mainframe by interposing a column joint, and is connected to the lower end of said first column; a pair of first wheels rotatably installed at the lower end of said second column ; and a pair of second wheels rotatably installed one end of said mainframe.

Further, the built-up multipurpose structure assembly for forming a rocking chair comprise: a mainframe which is arranged lengthwise; sub frames which are transversely connected opposite ends of said mainframe; a pair of rocking carriers which are connected opposite ends portions of said first axis inserted in said sub frames by means of joint for rocking motion in place; and a seat plate mounted on said mainframe

by means of joint.

Further, the built-up multipurpose structure assembly for forming a shopping cart comprises a mainframe which is arranged lengthwise; the first column, at either end of which the handlebar can be mounted or dismounted; the second column, which is fixed to one end of the mainframe by interposing a column joint, with the other end fixed at the middle of the mainframe by interposing a joint, and is connected to one end of the first column; a sub frame, which is connected crosswise to the other end of the mainframe opposite the end that is connected to the column joint; wheels installed at opposite ends of the sub frame in a rotatable manner by means of the second axis; a vertical carriage fixed to the mainframe; and a horizontal carriage connected roughly perpendicular to the vertical carriage.

Further, the built-up multipurpose structure assembly for forming a boat comprise: a mainframe which is arranged lengthwise; a pair of sub frames traversly connected to opposite ends of said mainframe; a boat carrier coupled with opposite ends of the sub frames by interposing the connecting link, wherein the end portion of the connecting link is secured to the clamp fixed on the boat carrier; and a seat plate mounted on said mainframe.

Brief Description of the Drawings For a fuller understanding of the present invention, reference is made to the following description with the accompanying drawings, in which: Fig. 1A is an exploded perspective view of a built-up multipurpose

structure assembly in accordance with the first embodiment of the present invention; Fig. 1B is an assembled perspective view of a built-up multipurpose structure depicted in Fig. 1A, for illustrating a triangular bicycle; Fig. 2 is a vertical sectional view of a front wheel depicted in Fig.

1A ; Figs. 3A and 3B are a plane view and a side view of the built-up multipurpose structure in accordance with the second embodiment of the present invention illustrating an eccentric triangular bicycle, respectively; Figs. 4A and 4B are a plane view and a side view of the built-up multipurpose structure in accordance with the third embodiment of the present invention illustrating a quadrangular bicycle, respectively ; Figs. 5A to 5C are a plane view, a side view and a front view of the built-up multipurpose structure in accordance with the fourth embodiment of the present invention illustrating a seat car, respectively; Figs. 6A and 6B are views similar to Figs 5A and 5B but depict the built-up multipurpose structure in accordance with the fifth embodiment of the present invention illustrating an eccentric seat car; Figs. 7A and 7B are a plane view and a side view of the built-up multipurpose structure in accordance with the sixth embodiment of the present invention illustrating multi-seat bicycles, respectively; Figs. 8A and 8B are views similar to Figs 7A and 7B but depict the built-up multipurpose structure in accordance with the seventh embodiment of the present invention illustrating multi-seat cars;

Figs. 9A to 9C are a plane view, a side view and a front view of the built-up multipurpose structure in accordance with the eighth embodiment of the present invention illustrating a wide kick board, respectively; Figs. 10A and 10B are views similar to Figs 9A and 9B but depict the built-up multipurpose structure in accordance with the ninth embodiment of the present invention illustrating a narrow kick board; Figs. 11A to 11C are a plane view, a side view and a front view of the built-up multipurpose structure in accordance with the tenth embodiment of the present invention illustrating rocking chairs, respectively, and Figs 11D is an exploded perspective view of illustrating a rocking carrier connecting structure; Figs. 12A and 12B are views similar to Figs 11A and 11B but depict the built-up multipurpose structure in accordance with the eleventh embodiment of the present invention illustrating rocking chairs with handlebars; Figs. 13A to 13C are a plane view, a side view and a front view of the built-up multipurpose structure in accordance with the twelfth embodiment of the present invention illustrating quadrangular skis with short ski carriers, respectively, and Figs 13D is an exploded perspective view of illustrating a ski carrier connecting structure; Figs. 14A and 14B are views similar to Figs 13A and 13B but depict the built-up multipurpose structure in accordance with the thirteenth embodiment of the present invention illustrating quadrangular skis with long ski carriers;

Figs. 15A and 15B are views similar to Figs 13A and 13B but depict the built-up multipurpose structure in accordance with the fourteenth embodiment of the present invention illustrating seat skis; Figs. 16A and 16B are views similar to Figs 13A and 13B but depict the built-up multipurpose structure in accordance with the fifteenth embodiment of the present invention illustrating triangular skis with handlebars; Figs. 17A to 17C are a plane view, a front view and a side view of the built-up multipurpose structure in accordance with the sixteenth embodiment of the present invention illustrating shopping carts, respectively, and Figs 17D is an exploded perspective view of illustrating carriages connecting structure; Figs. 18A to 18C are a plane view, a front view and a side view of the built-up multipurpose structure in accordance with the seventeenth embodiment of the present invention illustrating a boat, respectively; and Figs. 19A and 19B are a plane view, a side view of the built-up multipurpose structure in accordance with the eighteenth embodiment of the present invention illustrating a ski carrier, respectively.

Description of the Preferred Embodiments Referring first to Figs. 1 and 2, there is illustrated an exploded views of the exploded state and assembled state of the built-up structure for a triangular bicycle according to the first embodiment of the present invention. In this detailed description,"triangular"refers to the triangular

arrangement of the front and rear wheels viewed from plane, and "quadrangular"refers to the quadrangular arrangement of the front and rear wheels viewed from plane. Also, in each embodiment, the same reference characters designate the same or corresponding parts.

The overall construction of the triangular bicycle illustrated in Figs.

1A and 1B is consisted of the mainframe 12 arranged lengthwise, the first column and second column 2 and 10 installed at one end 12 of the mainframe 12 in a rotatable manner by interposing column joint 8, the handlebar 4 fixed at the upper end 2 of the first column 2, a pair of first wheels 18 installed at one end 10 of the second column 10 in a rotatable manner and a pair of second wheels 20 installed at the other end 12'of the mainframe 12 in a rotatable manner, and a seat 24 fixed to the mainframe 12 by interposing a plurality of joints 48 and 50 Here, the mainframe 12 constituting the main body has a plurality of through holes 12a to 12d formed to make it possible to fix parts such as the seat 24 in necessary positions. One end 12 of the mainframe 12 has a hole 12a formed to connect with the column joint 8, and the other end 12 of the mainframe 12 has also a hole 12b formed to connect with a sub frame 14. Meanwhile, cushion 25 is mounted on the seat 24 to provide cushioning for infants.

To assemble, insert one end 12 of the mainframe 12 between both flanges 8 formed on the column joint 8, and then insert and fasten cap nut 58 and screw 59 in the holes 8a, 12a while aligning the hole 12a formed at one end 12 of the mainframe 12 with the hole 8a formed at the

male flange 6. Next, connect the other end 12 of the mainframe 12 with the connecting bracket 43 fixed at the center mounting portion 14 of the sub frame 14, and then connect the first wheel axis 42 by passing it through the holes 14a, 12b while aligning the hole 12b formed at the other end 12 of the mainframe 12 with the through hole 14a formed on the sub frame 14. At opposite ends of the first wheel axis 42 is rotatably installed the pair of second wheels 20. A connecting bracket 43 used for connecting the mainframe 12 with the sub frame 14 has two holes 43a and 43b formed, of which the upper hole 43a has one end 12 of the mainframe 12 fixed by bolt and the lower hole 43b has the first wheel axis 42 inserted and fixed.

In the column joint 8 connected to one end 12 of the mainframe 12 by the same cap nut 58 and the same screw 59, install the first column 2 and second column 10, which are providing steering means. Here, one upper end 2 of the first column 2 has screw hole 2a formed, and through the screw hole 2 handlebars 4 are screw-connected to opposite ends. The bottom of the first column 2 has a hole 26 at the rearward through which an adjust screw 80 is screw-connected.

In this embodiment, extension column 6 is arranged between the first column 2 and the second column 10. The inside of the first column 2 is hollow so that the extension column 6 can be inserted, and a through hole 6a is formed in the extension column 6 to insert cylinder part 10 of the second column 10. And two level adjust holes 6b and 6c are formed on the back of the extension column 6, and two level adjust holes 10b and 10c are formed also on the cylinder part 10 of the second column

10. On the back of the first column 2, a hole 2b is formed to connect selectively with either of the level adjust holes 6b, 10b of the top or the level adjust holes 6c, l Oc of the bottom.

So, to assemble, insert the cylinder part 10 of the second column 10 into through hole 8b of the column joint 8 and through hole 6a of the extension column 6 one after another, and fix the first column 2 at a level according to the purpose of use with screw 59 while the extension column 6 is inserted into the inside of the first column 2.

For use in a bicycle as in this embodiment, the column level should be low, so connect and fasten with screw 80 while the hole 2b of the first column 2 is aligned with the bottom level adjust holes 10b and 8b. For use in a putting cart or shopping cart to be illustrated in Figs. 9C and 17B, the column level should be high, so connect and fasten with screw 80 while the hole 2b of the first column 2 is aligned with the top level adjust holes 10c and 6c.

At the bottom end of the second column 10 is formed the through hole 10a that is inserted through the second wheel axis 44. To assemble, insert opposite ends of the second wheel axis 44 into the hole 18a formed on the inner surface of the pair of first wheels 18. The center of the second wheel axis 44 is made of a circular section to match with the through hole 10a, and opposite ends are made of a quadrangular section to match with the quadrangular hole 18a of the first wheels 18.

Also, on the outer surface of the first wheels 18 are formed a screw hole 18b to insert screw 22 equipped at one end of the pedal 22. As illustrated in Figs. 2, rubber tire 18b is put on the outer circumference of

the first wheel 18 to absorb shock, and reinforcing rib 18 is formed on the inner surface thereof.

The pair of second wheels 20 arranged in the back opposite the pair of first wheels 18 are installed on the back frame 14 in a rotatable manner by the first wheel 42. At this time, on the inner surface of the second wheels 20 are formed center hole 20a to insert and fix opposite ends of the first wheel axis 42. On both sides of this center hole 20a are formed eccentric holes 20b to induce eccentric rotation of the second wheels 20. Accordingly, if the first wheel axis 42 is connected to the center hole 20a, the second wheels 20 rotate concentrically with the first wheel axis 42 as illustrated in Fig. 2; if the first wheel axis 42 is connected to the eccentric hole 20b, eccentric rotation is induced since the second wheels 20 are assembled eccentrically with the first wheel axis 42 as illustrated in Figs. 3. Therefore, the user can enjoy bicycle rides better through eccentric rotation and can have a feeling as if he were riding in mountains.

In the center of the mainframe 12 is installed the seat 24 for the user to sit on. One or more joints 48 and 50 are used to fix the seat 24, and on the bottom surface of the seat 24 are formed one or more flanges 24 and 24.

To assemble, connect and fasten a cap nut 58 and screw 59, aligning the bottom hole 48a of the joint 48 with the top hole 48b of the joint 48; connect and fasten a cap nut 54 and a screw 55, aligning the top hole 48b of the joint 48 with the through hole 24a formed on the front flange 24 of the seat 24. In the same manner, connect and fasten the same cap nut

58 and the same screw 59, aligning the bottom hole 50a of the joint 50 arranged in the rear with the hole 12d of the mainframe 12; connect and fasten the same cap nut 54 and the same screw 55, aligning the top hole 50b of the joint 50 with the through hole 24b formed on the rear flange of the seat 24. In this detailed description, the"front"means toward the first wheels 18, the direction of bicycle moving forward, and the"rear" means toward the second wheels 18, the direction of bicycle moving rearward. The completion of assembly is illustrated in Fig. 2.

Referring now to Fig. 3, there is illustrated the assembly of the structure for an eccentric triangular bicycle according to the second embodiment of the present invention; Fig. 3A is a plan view and Fig. 3B is a side view of the assembly, respectively. This embodiment illustrates a structure in which the second wheels 20 can make eccentric rotation, while the second wheels 20 illustrated in Fig. 1 can make a coaxial rotation. In the embodiments below, the structure is similar to that of the bicycle illustrated in Fig. 1, so the description made in Fig. 1 on the assembly relations between parts is omitted.

For this, as illustrated in Fig. 3A, one end of the first wheel axis 42 is connected to the rear eccentric hole 20b of the second wheels 20, and the other end of the first wheel axis 42 is connected to the front eccentric hole 20b of the second wheel axis 20. Accordingly, variation as much as the distance between eccentric holes 20b and 20b'is generated between both wheels 20 as illustrated in Fig. 3b, so the second wheels 20 can make eccentric rotation during the ride. This can make you feel like

riding in mountains.

Referring now to Fig. 4, there is illustrated the assembly of the structure for a quadrangular bicycle according to the third embodiment of the present invention; Figs. 4A and 4B are a plane view and a side view of the assembly, respectively. In this embodiment, the distance between the pair of first wheels 18 is longer than that of the first embodiment and the second embodiment illustrated in Figs. 1 and 2 to insure the driving stability.

For this, one end of the mainframe 12 is connected to the column joint 8 and the other end of the frame 12 is connected to the sub frame 14 with the connecting bracket 43. Then, the pair of second wheels 20 are secured to ends, respectively, of the first wheel shaft 42 inserted in the sub frame 14 so as to be rotatable therewith, while the pair of first wheels 18 are secured to opposite ends, respectively, of the first wheel shaft 42 connected to the lower end of the second column 10 so as to be rotatable therewith. Accordingly, the user can ride the bicycle in stable and can make feel like driving a vehicle.

Referring now to Fig. 5, there is illustrated the assembly of the structure for a seat car according to the fourth embodiment of the present invention; Figs. SA to 5C are a plane view, a side view and a front view of the assembly, respectively. In this embodiment, the handlebar 4 mounted on the upper end of the second arm 2 is eliminated and the seat 24 is replaced by a seat plate 32, in order to providing a seat car for a children who cannot ride the bicycle illustrated in Figs. 4A and 4B.

To assemble, opposite ends of the mainframe 12 firstly connect to

center of the sub frames 14 with the connecting bracket 43, and then the first wheels 18 and the second wheels 20 are secured to opposite ends of the first wheel shaft 42 inserted in the sub frames 14, respectively so as be rotatable therewith.

The seat plate 32 is mounted on the mainframe 12 which having a seat back 26 for supporting a waste. Here, the seat back 26 has a plurality (in this embodiment, three) of projections 26a which is inserted into a plurality of holes of the seat back 26 for assembling. The seat car according to this embodiment is pertinent for little children riding in room.

Referring now to Fig. 6, there is illustrated the assembly of the structure for an eccentric seat car according to the fifth embodiment of the present invention; Figs. 6A and 6B are views similar to Figs SA and 5B but depict the eccentric structure of the second wheels 20, respectively.

This embodiment illustrates a structure in which the second wheels 20 can make eccentric rotation, as illustrated in Figs. 3A and 3B. For the eccentric rotation, as illustrated in Figs. 6A and 6B, one end of the first wheel axis 42 is connected to the rear eccentric hole 20b of the second wheels 20, and the other end of the first wheel axis 42 is connected to the front eccentric hole 20b of the second wheel axis 20. Accordingly, variation as much as the distance between eccentric holes 20b and 20b' is generated between both wheels 20 as illustrated in Fig. 6B, so the second wheels 20 can make eccentric rotation during the ride. This can

make you feel like riding in mountains as mentioned in Figs 3A and 3B.

Fig. 7 shows the assembly of the structure for the multi-seat bicycle according to the sixth embodiment of the present invention; Figs. 7A and 7B are a plane view and a side view of the assembly, respectively. The multi-seat bicycle is made by the combination of the bicycle assembly illustrated in Figs. 1A and 1B and the seat car assembly illustrated in Figs. 5A to 5C.

As illustrated in the drawings, one end of the rear mainframe 12 is connected to a connecting frame 74 with the connecting bracket 43 and the other end of the mainframe 12 is connected to the center of the sub frame 14. The connecting frame 74 is coupled with another connecting frame 72 connected to the front mainframe 12 by using a pin 70, so that the bicycle assembly are coupled with the seat car to form the multi-seat bicycles. One end of the front mainframe 12 is connected to the second column 10 by interposing column joint 8 and the other end of the front mainframe 12 is connected to the sub frame 14, while opposite ends of the rear mainframe 12 are connected to the sub frames 14. Since three pairs of second wheels 20 are rotatably secured to opposite ends of the first wheel shaft 42 inserted in the sub frame 14, respectively, and the handlebar 4 are mounted on the first column 2, the multi-seat bicycle can provide a bicycle and a seat car for at lest two users.

Figs. 8A and 8B are views similar to Figs 7A and 7B but depict the built-up multipurpose structure in accordance with the seventh embodiment of the present invention illustrating multi-seat cars. In this embodiment, the bicycle illustrated in Figs. 7A and 7B is replaced by the

seat car also illustrated in Figs. 7A and 7B, that is the multi-seat car comprising two seat cars.

As illustrated in the drawings, rear end of the connecting frame 72 connected to the front mainframe 12 is coupled with the front end of the another connecting frame 74 connected to the rear mainframe 12 so as to provide multi-seat cars which can make users feel like riding a mini train.

Referring now to Fig. 9, there is illustrated the assembly of the structure for a wide kick board according to the eighth embodiment of the present invention; Figs. 9A to 9C are a plane view, a side view and a front view of the assembly, respectively. In present and the next embodiments,"wide"refers to the distance between both the second wheels is long by using the sub frame 14, and"narrow"refers to distance that of is short by not using the sub frame 14.

As illustrated in the drawings, the wide kick board comprise a mainframe 12 which is arranged lengthwise, a connecting frame 16 connected one end of the mainframe 12, the first column 2 on which the handlebar 4 are mounted; the second column 10 fixed to one end of the mainframe 12 by interposing a column joint 8, and is connected to the lower end of the first column 2; a pair of wheels 20 and 20 rotatably installed at the lower end of the second column 8 at opposite ends of the second axis 42 inserted the sub frame 14, respectively. The first column 2 and the second column 10 are connected by interposing extension column 6 for adjusting the height of the first column 2.

Front end of the connecting frame 16 is connected to the column

joint 8 with the cap nut illustrated in Figs. 1 and rear end thereof is connected to the mainframe 12 also with the screw 59. To use the kick board, there is no need to have the pedal and seat illustrated in Figs. 1A and 1B, thus the first wheels 18 illustrated in Figs 1A and 1B is replaced by the second wheels 20.

Figs. 10A and 10B are views similar to Figs 9A and 9B but depict the built-up multipurpose structure in accordance with the ninth embodiment of the present invention illustrating a narrow kick board. In this embodiment, the second wheels 20 are rotatably installed to rear end of the mainframe 12 using no sub frame in order to ride more speedily than that of illustrated in Figs. 9A and 9B.

Referring now to Fig. 11, there is illustrated the assembly of the structure for an rocking chair according to the tenth embodiment of the present invention; Figs. 11A to 11C are a plane view, a side view and a front view of the assembly, respectively.

As illustrated in the drawings, the rocking chairs comprise a mainframe 12 which is arranged lengthwise, sub frames 14 which are transversely connected opposite ends of the mainframe 12, a pair of rocking carriers 36 which are connected opposite ends portions 42 of the first axis 42 inserted in the sub frame 14 by means of joint 46 for rocking motion in place, a seat plate 32 mounted on the mainframe 12 by means of joint 50. The seat plate 32 is provided with a seat back 26 for the waste rest as mentioned in Figs. 5A to 5C. If a child or an adult seat on the seat plate 32 and moves ones body backward and forward, the rocking carrier 36 permits the rocking chair to perform a rocking motion.

The rocking carrier connecting structure illustrated in Figs. I 1D comprises a joint 46 having two holes 46a and 46b which are aligned with a hole 36a formed at opposite ends of the rocking carrier 36 and the end portion 42 of the first axis 42, respectively. The rocking carrier 36 has two holes 36a and 36b at opposite ends 36 and 36 for passing the screw 59 inserted through the lower holes 46a and 46b of the joints 46, respectively.

To assemble, insert one end 36 of the carrier 36 between both flanges vertically elongated form the both sides of the joint 46, and then insert and fasten the screw 59 and cap net in the holes 46a and 36a.

Next, insert and fix the hole 46b of the joint 46 to the one end portion 42 of the first axis 42. The end 36 of the carrier 36 can pivotly coupled with the other end portion 42 of the first axis 42 by means of the joint 46 in the same manner as mentioned above.

Referring now to Fig. 12, there is illustrated the assembly of the structure for a rocking chair with handlebars according to the eleventh embodiment of the present invention; Figs. 12A and 12B are views similar to Figs 11 A and 11B but depict the assembly, respectively. In this embodiment, the seat plate 32 of the rocking chair illustrated in figs. 11 A to 11 C is replaced by the seat 24 while adding the first and the second columns 8 and 10 with handlebars 4.

One end of the rocking carrier 36 is connected to the end portion 42 of the first axis 42 inserted in the lower hole of the second column 10 by means of the joint 46 and the other end thereof is connected to the end portion 42 of the first axis 42 inserted in the sub frame 14. Since the

user ride on the seat 24 fixed to the mainframe 12, the moving range of the rocking chair is greater than that of none handlebar type rocking chair illustrated in Figs 11 A to 11C.

Referring now to Fig. 13, there is illustrated an assembly of the structure for quadrangular skis with short ski carriers according to the twelfth embodiment of the present invention, Figs. 13A to 13C are a plane view, a side view and a front view of the assembly, respectively.

The quadrangular skis are designed to ride on snow field or grass plot.

As illustrated in drawings, the whole construction of the quadrangular skis are similar to that of the quadrangular bicycle mentioned in Figs. 4A and 4B except the replace of second wheels 20 by short ski carriers 40. Two front ski carriers 40 are connected to the end portion 42 of the first axis 40 inserted in the front sub frame 14 by means of joints 50 and 46 while two rear carriers 40 are connected to the end portion 42 of the first axis 42 inserted in the rear sub frame 14.

The short ski carrier 40 has two flanges 40 vertically formed on the surface thereof, in which the lower portion having a hole 50a of the joint 50 is inserted as illustrated in Fig 13D. The joint 50 has a plurality of holes 50a and 50b for connecting the short ski carrier 40 with the joint 46, wherein the pair of holes 50b are formed on the upper end portion of opposite flanges thereof. Also, the joint 46 has two pair of holes 46a and 46b for connecting the joint 50 with the end portion 42 of the first axis 42, which are formed on opposite flanges thereof.

To assemble, the lower portion having a hole 50a of the joint 50 between both flanges 40 of the short ski carrier 40, and then insert and

fasten cap nut 59 and screw in the holes 40a formed on the flanges 40 while aligning with the hole 50a. Next, insert the joint 46 between both flanges having holes 50b of the joint 50, and then insert and fasten cap nut 59 and screw in the lower holes 46a of joint 46 and 50b while coupling the upper holes 46b of joint 46 to the end portions 42 of the first axis 42.

Referring now to Fig. 14, there is illustrated the assembly of the structure for quadrangular skis with long ski carriers according to the thirteenth embodiment of the present invention; Figs. 14A and 14B are views similar to Figs 13A and 13B but depict the assembly having a long ski carrier, respectively. In this embodiment, the short ski carriers 40 illustrated in Figs. 13A to 13C by the long ski carriers 38 for establishing a skiing stabilization. As illustrated In fig. 14b, one end of the ski carrier 38 is connected to the end portion 42 of the first axis 42 rotatably mounted on the lower end of the second column 10 by means of joints 50 and 46 in same manner as mentioned in Figl3D, while the other end of the ski carrier 38 is connected to the end portion 42 rotatably mounted on the sub frame 14 also by means of joints 50 and 46.

Referring now to Fig. 15, there is illustrated the assembly of the structure for seat skis according to the fourteenth embodiment of the present invention. In this embodiment, the seat plate 32 having a waist back 26 is mounted on the mainframe 12 instead of the seat 24 illustrated in Figs. 14A and 14B. Both opposite ends of the ski carrier 38 are connected to the end portions 42 of the first axes 42 rotatably mounted on the sub frame 14 by means of joints 50 and 46 in same manner as

mentioned in Figl3D, while the handlebar 4 illustrated in Figs. 14A and 14B is removed.

Referring now to Fig. 16, there is illustrated the assembly of the structure for triangular skis with handlebars according to the fifth embodiment of the present invention. In this embodiment, the front short ski carrier 40 is connected to the end portion 42 of the first axis 42 rotatably mounted on the lower end of the second column 10 by means of the joints 50 and 46 without using the sub frame illustrated in Figs.

13A to 13c for permitting a steering of the handlebar 4.

Referring now to Fig. 17, there is illustrated the assembly of the structure for a shopping cart according to the sixteenth embodiment of the present invention; Figs. 17A to 17C are a plane view, a front view and a side view of the assembly, respectively.

As illustrated in drawings, the shopping cart comprise a mainframe 12 which is arranged lengthwise, the first column 2 on which the handlebar 4 is mounted; the second column 10 coupled with the lower end of the first column 2 by interposing an elongate column 6, whose one end is connected to one end of the mainframe 12 by interposing the column joint 8 and the other end is connected to the center of the mainframe 12 by interposing the joint 50; a sub frame 14 connected to the other end of the mainframe 12 opposing the end connected to the column joint 8; a pair of wheels 20 are secured to the first wheel axis 42 inserted the sub frame 14, respectively, so as to be rotatable therewith; a vertical carriage 30 mounted on the mainframe 12; and a horizontal carriage 28 perpendicularly arranged the vertical carriage 30.

As illustrated in Figs 17D, the vertical carriage 30 has a plurality of projections 30 and 30 having coupling holes 30a and 30b at one side thereof, the horizontal carriage 28 also has a plurality of projections 28 and 28 having coupling holes 28a and 28a at one side thereof for coupling with the vertical carriage 30. To assemble, the plurality of projections 28 and 28 insert between the plurality of the projections 30 and 30, and then pass through commonly used a long screwed bolt and fasten with nut (not illustrated) while aligning the holes 28a and 28a of the projections 28 and 28 with the holes 30a and 30b of the projections 30 and 30. In this state, the vertical carriage 30 can pivotly fold against the horizontal carriage 28 by interposing the long screwed bolt (not illustrated) for compacting vertical size of the shopping cart.

Referring now to Fig. 18, there is illustrated the assembly of the structure for a boat according to the seventeenth embodiment of the present invention; Figs. 18A to 18C are a plane view, a front view and a side view of the assembly, respectively; As illustrated in drawings, the boat comprise a mainframe which is arranged lengthwise; a pair of sub frame 14 traversly connected to opposite ends of the mainframel2; a boat carrier 60 coupled with opposite ends of the sub frame 14 by interposing the connecting link 90; and a seat plate mounted on the mainframe 12. The end portion of the connecting link 90 is secured to the clamp 92 fixed on the boat carrier 60.

Referring now to Fig. 19, there is illustrated the assembly of the structure for a ski carrier according to the eighteenth embodiment of the

present invention; Figs. 19A and 19B are a plane view, a side view of the ski carrier, respectively. As illustrated in drawings, the ski carrier 38 is provided with a foot gate 94 vertically installed approximately the center thereof and an inclined ring 96 installed rearward the foot gate 94. Thus, the user can ride a ski carrier through inserting ones foot in the foot gate 94 and being supported by the inclined ring 96.

According to the invention described above, the structure made from a plurality of assembled parts has not only a given shape but also durability enough for use, so it is possible to use it in real life. And since the user can embody it according to the purpose of use into various things such as skis, rocking chairs, shopping carts, and boats as well as single-seat or multi-seat bicycles, it is possible for not only children but also adults to make and use structures according to their own tastes.