AU2012310424A1 - Sawtooth structure and toy block comprising the structure - Google Patents

Abstract

The present invention relates to a sawtooth structure in which an external sawtooth structure and an internal sawtooth structure engage with each other to support a fine joint angle adjustment function, and to a toy block comprising such structure. A sawtooth structure of the present invention comprises an external sawtooth structure and an internal sawtooth structure, wherein the external sawtooth structure has an inner surface with one or more areas on which an inner sawtooth portion of the external sawtooth structure containing at least two or more inner sawteeth of the external sawtooth structure is formed, and the internal sawtooth structure has an outer surface with one or more areas on which an outer sawtooth portion of the internal sawtooth structure that corresponds to the inner sawtooth portion of the external sawtooth structure and that contains at least two or more outer sawteeth of the internal sawtooth structure is formed. Thus, the coupling angle of the blocks to be coupled by the magnetic force of the magnet can be finely adjusted, and as the coupling angle of the blocks is finely adjusted, the coupled surfaces of the blocks are smooth.

Description

1/31 SAWTOOTH STRUCTURE AND TOY BLOCK COMPRISING THE STRUCTURE TECHNICAL FIELD [1] The present invention relates to a sawtooth structure, a toy block comprising the structure, and a toy set comprising the toy block, and more particularly, a sawtooth structure capable of supporting a fine assembly angle adjustment function in cooperation of an external sawtooth structure and an internal sawtooth structure, a toy block comprising the structure, and a toy set comprising the toy block. BACKGROUND ART [2] A plurality of products, as toy blocks utilizing magnets, have been distributed so far. Those toy blocks commonly use a coupling force (or an assembling force) generated by the magnets. How to couple the magnets to the toy blocks and the coupling structure are important. A method using a cap was generally used in the conventional art. However, a magnet block utilizing such method using the cap had a sawtooth structure merely on a surface thereof. This has brought about many disadvantages in making structures. [3] First, the magnet block utilizing the method using the cap is useful upon building a structure. However, when a stereoscopic structure, namely, a three-dimensional structure is built, such structure may be easily collapsed even due to a small impact around it. In addition, the very structure is difficult to be sustained due to getting twisted easily. [4] Also, when a structure is built using the magnet blocks having the sawtooth structure merely on their surfaces, for example, when a structure is generated using triangular blocks, square or rectangular blocks, pentagonal blocks and the like, those blocks are not aligned at edges thereof. This lowers completion of the structure and causes a limitation in completion of a stereoscopic structure. [5] That is, the failure of an accurate adjustment of a coupling angle has caused assembled surfaces generated by assembling the blocks or extending surfaces of the blocks to be non smooth, when viewed from various angles, and made outer surfaces of the structure uneven. [6] Accordingly, it is fully required to develop an invention, which is capable of making an 2/31 appearance of a structure aesthetic by forming assembled surfaces of blocks or extending surfaces of the blocks to be smooth, when viewed from various angels, in a manner of allowing an assembly angel (a coupling angle or a joint angle) between the blocks to be accurately (or finely) adjusted. DISCLOSURE Technical Problem [7] The present invention has been made keeping in mind the drawbacks of the related art, and a first object of the invention is to provide a sawtooth structure having a fine assembly angle (a coupling angle or a joint angle) adjustment function. [8] A second object of the invention is to provide a toy block having a sawtooth structure with a fine assembly angle adjustment function. [9] A third object of the invention is to provide a toy set having a plurality of toy blocks each having a sawtooth structure with a fine assembly angle adjustment function. Technical Solution [10] In order to achieve the above object, a sawtooth structure capable of being mounted to a toy block may include an external sawtooth structure, and an internal sawtooth structure, wherein an inner sawtooth portion having at least two inner sawteeth may be formed on at least a part of an inner surface of the external sawtooth structure, and wherein an outer sawtooth portion having at least two outer sawteeth may be formed on at least a part of an outer surface of the internal sawtooth structure to correspond to the inner sawtooth portion of the external sawtooth structure. [11] Preferably, the inner sawtooth portion of the external sawtooth structure may be formed on the inner surface of the external sawtooth structure, and the outer sawtooth portion of the internal sawtooth structure may be formed on the outer surface of the internal sawtooth structure. The inner sawtooth portion of the external sawtooth structure may be divided into an inner sawtooth area and an inner non-sawtooth area. The outer sawtooth portion of the internal sawtooth structure may be divided into an outer sawtooth area and an outer non-sawtooth area. [12] Preferably, a flat area of the inner surface occupied by the inner non-sawtooth area of the external sawtooth structure may be greater than a flat area of the inner surface occupied by the inner sawtooth area of the external sawtooth structure by more than a predetermined ratio. A flat 3/31 area of the outer surface occupied by the outer non-sawtooth area of the internal sawtooth structure may be greater than a flat area of the outer surface occupied by the outer sawtooth area of the internal sawtooth structure by more than the predetermined ratio. [13] Preferably, the predetermined ratio may be greater than 1 and smaller than 10. [14] Preferably, the internal sawtooth structure may be spaced from the external sawtooth structure so as to be rotatable in the external sawtooth structure. The outer sawtooth area of the outer sawtooth portion of the internal sawtooth structure may go over the inner sawtooth area of the inner sawtooth portion of the external sawtooth structure. [15] Preferably, the number of inner sawteeth constructing the inner sawtooth portion of the external sawtooth structure and the number of inner sawteeth constructing the outer sawtooth portion of the internal sawtooth structure may be in a ratio of 1:1. [16] Preferably, the number of inner sawteeth constructing the inner sawtooth portion of the external sawtooth structure and the number of inner sawteeth constructing the outer sawtooth portion of the internal sawtooth structure may be in a ratio of 1:n or 1:1/n (n=natural number more than 2 and less than 4). The outer non-sawtooth area of the internal sawtooth structure may be sufficiently greater than the outer sawtooth area of the internal sawtooth structure, such that at least two inner sawteeth of the external sawtooth structure can enter between the outer sawteeth of the internal sawtooth structure, when the number of inner sawteeth constructing the inner sawtooth portion of the external sawtooth structure is greater than the number of inner sawteeth constructing the outer sawtooth portion of the internal sawtooth structure. The inner non-sawtooth area of the external sawtooth structure may be sufficiently greater than the inner sawtooth area of the external sawtooth structure, such that at least two outer sawteeth of the inner sawtooth structure can enter between the inner sawteeth of the external sawtooth structure, when the number of the outer sawteeth constructing the outer sawtooth portion of the internal sawtooth structure is greater than the number of outer sawteeth constructing the inner sawtooth portion of the external sawtooth structure. [17] Preferably, at least one of the inner sawtooth of the external sawtooth structure or the outer sawtooth of the internal sawtooth structure may have a symmetric shape in left and right directions based on a peak.

4/31 [18] Preferably, at least one of the inner sawtooth of the external sawtooth structure or the outer sawtooth of the internal sawtooth structure may have an asymmetric shape in the left and right directions based on the peak. [19] Preferably, when both the inner sawtooth of the external sawtooth structure and the outer sawtooth of the internal sawtooth structure have the asymmetric shape in the left and right directions based on the peak, the inner sawteeth of the external and internal and the outer sawteeth of the internal sawtooth structure may be arranged in such a manner of minimizing rotation resistance in one direction and maximizing rotation resistance in an opposite direction. [20] Preferably, the external sawtooth structure may further include a surface sawtooth portion having at least two surface sawteeth or the internal sawtooth structure may further include a surface sawtooth portion having at least two surface sawteeth. [21] Preferably, the number of inner sawteeth of the external sawtooth structure and the number of surface sawteeth of the external sawtooth structure may be the same as each other. The inner sawteeth and the surface sawteeth of the external sawtooth structure may be arranged by a first arrangement method of arranging the inner sawtooth and the surface sawtooth of the external sawtooth structure on the same position, and a second arrangement method of arranging the surface sawtooth of the external sawtooth structure between the inner sawteeth of the external sawtooth structure. [22] Preferably, the number of inner sawteeth of the external sawtooth structure and the number of surface sawteeth of the external sawtooth structure may be different from each other, and the inner sawteeth and the surface sawteeth of the external sawtooth structure may be arranged in a manner of arranging the surface sawtooth between the inner sawteeth of the external sawtooth structure. [23] The number of outer sawteeth of the internal sawtooth structure may preferably be the same as or greater than the number of surface sawteeth of the internal sawtooth structure. [24] The internal sawtooth structure may preferably have a shape of a cone with an upper portion cut off, and be provided with a space having a magnet accommodating portion of more than a predetermined size for accommodating at least one magnet therein. [25] Preferably, the internal sawtooth structure may be completely accommodated in the 5/31 external sawtooth structure. A stopping jaw may be formed on a lower portion of the inner surface of the external sawtooth structure, so as to prevent separation of the internal sawtooth structure to outside when the internal sawtooth structure is accommodated in the external sawtooth structure. [26] Preferably, the external sawtooth structure may have a cylindrical outer shape which is wide in width and long in length. The inner shape of the external sawtooth structure may include an accommodating space for accommodating the internal sawtooth structure therein. [27] Preferably, a fixing force-reinforcing unit may further be formed on a lower circumferential portion of the external sawtooth structure to reinforce a fixing force of the external sawtooth structure. [28] Preferably, the fixing force-reinforcing unit may include a stepped portion having at least one step, formed along the circumferential portion. At least a part of the stepped portion may be provided with a portion having a radius greater than a radius of the external sawtooth structure. The stepped portion may include a portion having at least two types of radiuses. [29] Preferably, the stepped portion may include a first stepped portion and at least one second stepped portion. The maximum radius of the first stepped portion may be greater than that of the second stepped portion. The first stepped portion may be arranged closer to the surface sawtooth portion of the external sawtooth structure than the second stepped portion. A ratio that the radius of the first stepped portion is reduced when the first stepped portion is getting away from the surface sawtooth portion of the external sawtooth structure may be greater than a ratio that the radius of the second stepped portion is reduced when the second stepped portion is getting away from the surface sawtooth portion of the external sawtooth structure. [30] The present disclosure provides a toy block having the sawtooth structure. [31] Preferably, the toy block may be polyhedral, and the sawtooth structure may be mounted to at least one of a plurality of surfaces constructing the polyhedron. [32] Preferably, the polyhedron may essentially include at least one flat surface, and selectively include at least one curved surface. Advantageous Effects [33] According to the present disclosure, an assembly angle of blocks which are assembled 6/31 by a magnetic force of magnets may be accurately adjustable. [34] According to the present disclosure, by the accurate adjustment of the assembly angle of the blocks, an assembled surface generated by assembling the blocks or an extending surface of the blocks may become smooth, when viewed from various angles, and also outer surfaces of the block structure may be even. This may allow the assembled surface or extending surface of the blocks to be aesthetic. DESCRIPTION OF DRAWINGS [35] FIG. 1 is an exploded view of a sawtooth structure in accordance with one exemplary embodiment disclosed herein. [36] FIG. 2 is an outer view of an external sawtooth structure in accordance with the one exemplary embodiment disclosed herein. [37] FIG. 3 is an inner view of the external sawtooth structure in accordance with the one exemplary embodiment disclosed herein. [38] FIG. 4 is an outer view of an internal sawtooth structure in accordance with the one exemplary embodiment disclosed herein. [39] FIG. 5 is a view illustrating an engaged state between an inner portion of the external sawtooth structure and an outer portion of the internal sawtooth structure in accordance with the one exemplary embodiment disclosed herein. [40] FIG. 6 is a view illustrating an exemplary embodiment disclosed herein, in which a ratio between an inner sawtooth of the external sawtooth structure and an outer sawtooth of the internal sawtooth structure is 1:2. [41] FIG. 7 is a view illustrating an exemplary embodiment disclosed herein, in which the ratio between the inner sawtooth of the external sawtooth structure and the outer sawtooth of the internal sawtooth structure is 2:1. [42] FIG. 8 is a view illustrating an exemplary embodiment, in which the external sawtooth structure comprises 24 inner sawteeth and the internal sawtooth structure comprises 24 outer sawteeth to adjust an assembly angle more accurately. [43] FIG. 9 is a view illustrating an exemplary embodiment, in which a ratio between an inner sawtooth portion and a non-sawtooth portion of the external sawtooth structure is 1:4.

7/31 [44] FIG. 10 is a view illustrating an exemplary embodiment, in which two outer sawteeth of the internal sawtooth structure are present between the neighboring inner sawteeth of the external sawtooth structure when the ratio between the inner sawtooth portion and the non-sawtooth portion of the external sawtooth structure is 1:4. [45] FIG. 11 is a view illustrating one exemplary embodiment, in which the inner sawtooth of the external sawtooth structure has an asymmetric shape and the outer sawtooth of the internal sawtooth structure has a symmetric shape. [46] FIG. 12 is a view illustrating one exemplary embodiment, in which asymmetric sawteeth are arranged in a manner of maximizing rotation resistance in one direction and minimizing it in another direction due to both of the inner sawtooth of the external sawtooth structure and the outer sawtooth of the internal sawtooth structure having the asymmetric shape. [47] FIG. 13 is a view illustrating one exemplary embodiment of the external sawtooth structure with a stepped portion. [48] FIG. 14 is a view illustrating an exemplary embodiment of a toy block disclosed herein, which has the sawtooth structure engaged with a block. [49] FIG. 15 is a sectional view illustrating an assembled state between toy blocks with magnets in accordance with another exemplary embodiment disclosed herein. [50] FIG. 16 is a perspective view illustrating an assembled state of a sawtooth structure in accordance with the another exemplary embodiment disclosed herein. [51] FIG. 17 is an exploded view of the sawtooth structure of FIG. 16. [52] FIG. 18 is a longitudinal sectional view of FIG. 16. [53] FIG. 19 is a sectional view taken along the line 'II' of FIG. 18. [54] FIG. 20 is a longitudinal sectional view of a sawtooth structure in accordance with another exemplary embodiment disclosed herein. [55] FIG. 21 is a view illustrating a state where a sawtooth structure is stuck in a block with a curved surface. [56] FIG. 22 is a view of a sawtooth structure formed between two blocks, which illustrates a usage state of the present disclosure which is capable of finely adjusting a rotation for the assembly of the blocks.

8/31 [57] FIG. 23 is a view illustrating an exemplary embodiment of a toy set comprising various shapes of blocks in accordance with the present disclosure. BEST MODE [58] FIG. 1 is an exploded view of a sawtooth structure 10 in accordance with one exemplary embodiment disclosed herein. FIG. 2 is an outer view of an external sawtooth structure 100 disclosed herein. FIG. 3 is an inner view of the external sawtooth structure 100 disclosed herein. FIG. 4 is an outer view of an internal sawtooth structure 200 disclosed herein. A sawtooth structure 10 according to the present disclosure may include an external sawtooth structure 100 and an internal sawtooth structure 200. An inner sawtooth portion 110 may be formed on at least a part of an inner surface of the external sawtooth structure 100. An inner sawtooth portion 210, which corresponds to the inner sawtooth portion 110 of the external sawtooth structure 100, may be formed on at least a part of an outer surface of the internal sawtooth structure 200. A magnet accommodating portion 230 for accommodating a magnet therein may be formed in the internal sawtooth structure 200. Accordingly, blocks 300 each having the sawtooth structure 10 mounted thereto may be assembled with each other by a magnetic force of the magnet accommodated in the magnet accommodating portion 230. [59] As illustrated in FIGS. 1 to 5, the internal sawtooth structure 200 may be mounted or coupled into the external sawtooth structure 100. A clearance space more than a predetermined interval may be formed between the external sawtooth structure 100 and the internal sawtooth structure 200. The clearance space may allow the internal sawtooth structure 200 to be rotatable in the external sawtooth structure 100. When the clearance space is excessively small, a sawtooth mountain of an outer sawtooth 221-1 of the outer sawtooth portion 210 of the internal sawtooth structure 200 may not be able to go over an inner sawtooth 111-1 of the inner sawtooth portion 110 of the external sawtooth structure 100. This may cause a difficulty in rotation of the internal sawtooth structure 200, so as to disable a fine adjustment of a block-assembling angle as the core effect of the present disclosure. On the other hand, when the clearance space is excessively great, the internal sawtooth structure 200 may freely rotate, without appropriate resistance, within the external sawtooth structure 100. This may make it impossible to maintain the fine adjustment of the block-assembling angle as the core effect of the present disclosure. Therefore, the clearance 9/31 space may preferably be decided as great or small as preventing the free rotation of the internal sawtooth structure 200 and as having appropriate resistance when the outer sawtooth 221-1 of the internal sawtooth structure 200 goes over the inner sawtooth 111-1 of the external sawtooth structure 100. To this end, a virtual outer line connecting sawtooth mountains of the outer sawteeth 221-1 of the internal sawtooth structure 200 may preferably be greater than or the same as a radius of a virtual outer line connecting sawtooth mountains of the inner sawteeth 111-1 of the external sawtooth structure 100. [60] As illustrated in FIGS. 9 and 10, the inner sawtooth portion 110 of the external sawtooth structure 100 may be formed along an inner surface of the external sawtooth structure 100. The inner sawtooth portion 110 of the external sawtooth structure may be divided into an inner sawtooth area 111 with sawteeth and an inner non-sawtooth area 112 without a sawtooth. The inner non-sawtooth area 112 of the external sawtooth structure may preferably be formed in an alternating manner with the inner sawtooth area 111. That is, the inner sawtooth portion 110 of the external sawtooth structure 100 may have a structure that any sawtooth is not formed next a sawtooth. A flat area of the inner surface which is occupied by the inner non-sawtooth area 112 of the external sawtooth structure may preferably be greater than a flat area of the inner surface which is occupied by the inner sawtooth area 111 of the external sawtooth structure by more than a predetermined ratio. The ratio may be greater than or equal to 1 and smaller than 10, preferably, greater than 1 and smaller than or equal to 4. [61] Referring to FIG. 10, when the non-sawtooth area is greater than the sawtooth area of the inner sawtooth portion 110 of the external sawtooth structure, the outer sawtooth portion 210 of the internal sawtooth structure 200 may preferably be formed in such a manner that the sawtooth area thereof is greater than a non-sawtooth area. This may allow for the fine angle adjustment. That is, when a relatively small number of sawteeth are provided on the inner sawtooth portion 110 of the external sawtooth structure, it may be preferable that a relative great number of sawteeth are provided on the outer sawtooth portion 210 of the internal sawtooth structure. This structure may be more effective in view of the fine angle adjustment because one sawtooth of the inner sawtooth portion 110 of the external sawtooth structure goes over many sawteeth of the outer sawtooth portion 210 of the internal sawtooth structure.

10/31 [62] Meanwhile, the outer sawtooth portion 210 of the internal sawtooth structure 200 may be formed along an outer surface of the internal sawtooth structure 200. The outer sawtooth portion 210 of the internal sawtooth structure may be divided into an outer sawtooth area 221 with sawteeth and an outer non-sawtooth area 222 without a sawtooth. The outer non-sawtooth area 222 of the internal sawtooth structure 200 may preferably be formed in an alternating manner with the outer sawtooth area 221. A flat area of the outer surface which is occupied by the outer non-sawtooth area 222 of the internal sawtooth structure 200 may be greater than a flat area of the outer surface occupied by the outer sawtooth area 221 of the internal sawtooth structure by more than the predetermined ratio. The ratio may be greater than or equal to 1 and smaller than 10, preferably, greater than 1 and smaller than or equal to 4. [63] When a relatively small number of sawteeth are provided on the outer sawtooth portion 210 of the internal sawtooth structure, it may be preferable that a relative great number of sawteeth are provided on the inner sawtooth portion 110 of the external sawtooth structure. This structure may be more effective in view of the fine angle adjustment because one sawtooth of the outer sawtooth portion 210 of the internal sawtooth structure goes over many sawteeth of the inner sawtooth portion 110 of the external sawtooth structure. [64] As illustrated in FIGS. 6 and 7, the number of sawteeth of the inner sawtooth portion 110 of the external sawtooth structure and the number of sawteeth of the outer sawtooth portion 210 of the internal sawtooth structure may be in the ratio of 1:1, 1:n or n: 1 (n = an integer more than 2). The number n may preferably be more than 2 and less than 4. When the number n exceeds 4, a great difference of the number of sawteeth may be caused, which may result in a difficulty in the fine angle adjustment. [65] It may be better for each of the external sawtooth structure 100 and the internal sawtooth structure 200 to be provided with more sawteeth in view of the fine angle adjustment. For example, the fine angle adjustment may be improved more when each of the external sawtooth structure 100 and the internal sawtooth structure 200 is provided with 12 sawteeth than when each of the external sawtooth structure 100 and the internal sawtooth structure 200 is provided with 6 sawteeth. FIG. 8 illustrates an exemplary embodiment, in which the assembly angle (or the assembling angle) can be adjusted more accurately by providing 24 inner sawteeth for the 11/31 external sawtooth structure and 24 outer sawteeth 221-1 for the internal sawtooth structure. However, when the external sawtooth structure 100 and the internal sawtooth structure 200 are provided with an excessive number of sawteeth, respectively, a physical size of the external sawtooth structure 100 or the internal sawtooth structure 200 may be limited and accordingly a sawtooth cannot be large in physical size. When the sawtooth has an excessively small physical size, abrasion resistance or durability of the sawtooth may be lowered although there may be a deviation according to a material of the sawtooth constructing the sawtooth structure 10. Therefore, it may substantially be important to select an appropriate number of sawteeth according to the physical size of the sawtooth structure 10. [66] Referring back to FIG. 10, when the number of sawteeth of the inner sawtooth portion 110 of the external sawtooth structure is greater than the number of sawteeth of the outer sawtooth portion 210 of the internal sawtooth structure, the outer non-sawtooth area 222 of the internal sawtooth structure 200 may preferably have a sufficiently greater size than the outer sawtooth area 221. For example, it may be preferable that at least two inner sawteeth 111-1 of the external sawtooth structure are present between the outer sawteeth 221-1 of the internal sawtooth structure. On the other hand, when the number of outer sawteeth constructing the outer sawtooth portion 210 of the internal sawtooth structure is greater than the number of outer sawteeth constructing the inner sawtooth portion 110 of the external sawtooth structure, it may be preferable that the inner non-sawtooth area 112 of the external sawtooth structure may preferably have a sufficiently greater size than the inner sawtooth area 111 of the external sawtooth structure. For example, it may be preferable that at least two outer sawteeth 221-1 of the internal sawtooth structure are present between the inner sawteeth 111-1 of the external sawtooth structure. [67] Hereinafter, a shape of a sawtooth will be described with reference to FIGS. 11 and 12. As illustrated in FIG. 11, at least one of the inner sawtooth 111-1 of the external sawtooth structure or the outer sawtooth 221-1 of the internal sawtooth structure may be symmetric in left and right directions based on a peak. At least one of the inner sawtooth 111-1 of the external sawtooth structure or the outer sawtooth 221-1 of the internal sawtooth structure may be asymmetric in the left and right directions based on the peak. When a sawtooth mountain has the asymmetric shape, rotation resistance may be applied more to a rotation toward a sawtooth with a 12/31 sharp inclination than to a rotation toward a sawtooth with a gentle inclination. For example, as illustrated in FIG. 11, if the inner sawtooth 111-1 of the external sawtooth structure has an asymmetric shape and the outer sawtooth 221-1 of the internal sawtooth structure has a symmetric shape, relatively great rotation resistance may be generated when the outer sawtooth 221-1 of the internal sawtooth structure goes over the inner sawtooth 111-1 of the external sawtooth structure, which has a sharp inclination (or tilt). When the sawtooth structure 10 is mounted to blocks 300, the blocks 300 may be assembled with each other by a magnet accommodated in the magnet accommodating portion 230 of the internal sawtooth structure 200. In order to reduce rotation resistance for a fine adjustment of an assembling angle in a clockwise direction and increase rotation resistance for a fine adjustment of an assembling angle in a counterclockwise direction, when one of the external sawtooth structure 100 or the internal sawtooth structure 200 is provided with asymmetric sawteeth, those asymmetric sawteeth should be arranged in an appropriate manner. On the other hand, in order to further increase rotation resistance in one direction and further reduce rotation resistance in an opposite direction, as illustrated in FIG. 12, both the external sawtooth structure 100 and the internal sawtooth structure 200 may employ the sawteeth in the asymmetric shape, and a sawtooth direction of the asymmetric sawtooth of the inner sawtooth portion 110 of the external sawtooth structure and a sawtooth direction of the asymmetric sawtooth of the outer sawtooth portion 210 of the internal sawtooth structure may be arranged contrary to each other. Accordingly, upon rotation in one direction, when the inner sawtooth 111-1 of the external sawtooth structure having a sharp inclination goes over the outer sawtooth 221-1 of the internal sawtooth structure having a sharp inclination, rotation resistance in the one direction may be maximized. That is, when both the inner sawtooth 111-1 of the external sawtooth structure and the outer sawtooth 221-1 of the internal sawtooth structure are asymmetric in shape in the left and right directions based on the peak, the inner sawtooth 111-1 of the internal sawtooth structure and the outer sawtooth 221-1 of the internal sawtooth structure may be engaged in a manner of minimizing rotation resistance in one direction and maximizing rotation resistance in an opposite direction. [68] A surface sawtooth portion 220 may preferably be formed on at least a part of the outer surface of the internal sawtooth structure 200. A position where the surface sawtooth portion 220 13/31 of the internal sawtooth structure is formed may preferably be located on a surface of the block 300, namely, a surface on which the surface sawtooth portion 220 can come in contact with another block 300 which is a target to be assembled thereto. Sawteeth of the surface sawtooth portion 220 of the internal sawtooth structure may allow for a strong assembly between the blocks 300, thereby minimizing a fluctuation of the assembled portion (engaged position, surface to-surface, point-to-point, or position-to-position) upon rotation of the blocks 300. If the internal sawtooth structure is even and flat without having the surface sawtooth portion 220, when trying to rotate one of both the blocks 300 in the assembled state, it may cause a change in a relative position of the assembled portion between the surface sawtooth portion 220 of the internal sawtooth structure of one block 300 and the surface sawtooth portion 220 of the internal sawtooth structure of another block 300. Accordingly, the fine angle adjustment may become difficult when assembling the blocks. By virtue of the formation of the surface sawtooth portion 220 of the internal sawtooth structure, only when the surface sawtooth portions 220 of the internal sawtooth structures which are coupled by the magnetic force are strongly engaged with each other, a rotation as much as user's desire can be realized and accordingly a control of the fine assembly angle adjustment may be facilitated. [69] A surface sawtooth portion 120 may be formed on at least a portion of the outer surface of the external sawtooth structure 100. The surface sawtooth portion 120 of the external sawtooth structure constructing the sawtooth structure 10 of the magnetic block 300 may be engaged with the surface sawtooth portion 120 of the external sawtooth structure of the sawtooth structure 10 of the another block 300 by sawteeth of each of them, thereby increasing a coupling force therebetween. The surface sawtooth portion 120 of the external sawtooth structure may be used for a surface-to-surface coupling between the blocks 300 to which the sawtooth structures 10 are mounted. This structure may contribute to sustaining the assembled state between the blocks 300. A position where the surface sawtooth portion 220 of the internal sawtooth structure is formed may preferably be located on a surface of the block 300, namely, a surface on which the surface sawtooth portion 220 can come in contact with the another block 300 which is a target to be coupled thereto. Sawteeth of the surface sawtooth portion 220 of the internal sawtooth structure may allow for a strong assembly between the blocks 300, thereby minimizing the fluctuation of 14/31 the assembled portion (an assembled or engaged position, surface-to-surface, point-to-point, or position-to-position) upon rotation of the blocks 300. If the internal sawtooth structure is even and flat without having the surface sawtooth portion 220, when trying to rotate one of both the blocks 300 in the assembled state, it may cause a change in a relative position of the assembled portion between the surface sawtooth portion 220 of the internal sawtooth structure of the magnetic block 300 and the surface sawtooth portion 220 of the internal sawtooth structure of the another block 300. This may make it difficult to adjust a fine angle of the assembled blocks. Therefore, the surface sawtooth portion 120 of the external sawtooth structure should be provided to be engaged with the surface sawtooth portion 120 of another external sawtooth structure. This may facilitate a user to realize the rotation as much as desiring, resulting in an easy control of the fine assembly angle adjustment. [70] Meanwhile, the inner sawtooth 111-1 of the external sawtooth structure and the surface sawtooth 121-1 of the external sawtooth structure may be the same or independent of each other in view of number and arrangement. That is, the number of the inner sawteeth 111-1 of the external sawtooth structure may be the same as the number of surface sawteeth 121-1 of the external sawtooth structure. An arrangement of the inner sawteeth 111-1 of the external sawtooth structure and the surface sawteeth 121-1 of the external sawtooth structure may be selected from a first arrangement method in which the inner sawtooth 111-1 of the external sawtooth structure and the surface sawtooth 121-1 of the external sawtooth structure are arranged on the same position, and a second arrangement method in which the surface sawtooth 121-1 of the external sawtooth structure is located between the inner sawteeth 111-1 of the external sawtooth structure. On the other hand, the inner sawtooth 111-1 of the external sawtooth structure 100 and the surface sawtooth 121-1 of the external sawtooth structure may be different from each other in number. An arrangement of the inner sawteeth of the external sawtooth structure 100 and the surface sawteeth 121-1 of the external sawtooth structure may be achieved by the method in which the surface sawtooth 121-1 of the external sawtooth structure is arranged between the inner sawteeth of the external sawtooth structure. [71] In addition, the outer sawtooth 221-1 of the internal sawtooth structure and the surface sawtooth 211-1 of the internal sawtooth structure may be the same or independent of each other 15/31 in view of number and arrangement. That is, the number of the outer sawteeth 221-1 of the internal sawtooth structure may be the same as the number of surface sawteeth 211-1 of the internal sawtooth structure. However, an area of the surface sawtooth portion 220 of the internal sawtooth structure may be smaller than an area of the outer sawtooth portion 210 of the internal sawtooth structure. In this case, the number of outer sawteeth 221-1 of the internal sawtooth structure may preferably be greater than the number of surface sawteeth 211-1. [72] Referring back to FIG. 1, the internal sawtooth structure 200 may preferably include an inner space which may include a magnet accommodating portion 230 in which at least one magnet is accommodated. The inner space should be large enough to allow for a free rotation of the magnet. By ensuring the free rotation of the magnet, the assembly of the blocks 300 may be enabled, irrespective of NS positions of the another block 300 when the another block 300 approaches. [73] The internal sawtooth structure 200, as illustrated in FIG. 1, may preferably have a shape of a cone having an upper portion cut off. The surface sawtooth portion 220 of the internal sawtooth structure may be formed on all or part of a cut-off surface of the cone, and the outer sawtooth portion 210 of the internal sawtooth structure may be formed on all or part of an inclined surface of the cone. Of course, the internal sawtooth structure 200 may have a cylindrical shape. The surface sawtooth portion 220 of the internal sawtooth structure may be formed on all or part of an upper surface of the cylindrical shape, and the outer sawtooth portion 210 of the internal sawtooth structure may be formed on all or part of a side surface of the cylindrical shape. When the internal sawtooth structure 200 is cylindrical in shape, an inner circumferential surface of the external sawtooth structure 100 for accommodating the internal sawtooth structure 200 therein should be cylindrical to correspond to the shape of the outer sawtooth portion 210 of the internal sawtooth structure. [74] Still referring to FIG. 1, a separation-preventing means may be provided on a part of an inner surface of the external sawtooth structure 100. The separation-preventing means may facilitate the mounting or engagement of the internal sawtooth structure 200 or prevent the separation of the mounted or engaged internal sawtooth structure 200. The separation-preventing means of the internal sawtooth structure 200 may preferably be formed on a lower portion of the 16/31 inner surface of the external sawtooth structure 100 along a circumference of the inner surface. The separation-preventing means may preferably be formed in a form of a stopping jaw 130 for effectively preventing the separation of the internal sawtooth structure 200. That is, the internal sawtooth structure 200 may be completely accommodated within the external sawtooth structure 100. The stopping jaw 130 may be formed on the lower portion of the inner surface of the external sawtooth structure 100. When the internal sawtooth structure 200 is accommodated in the external sawtooth structure 100, the internal sawtooth structure 200 may not be easily separated to outside due to resistance of the stopping jaw 130. [75] The strong coupling (or assembling) between the external sawtooth structure 100 and the block 300 may be an important part in quality and lifespan of a product. The present disclosure may provide a technology in which the assembled state between the external sawtooth structure 100 and the block 300 are firmly maintained for an extended time by employment of a fixing force-reinforcing unit. Specifically, when the block 300 is made of a wooden material or a material having a certain level of elasticity, such as plastic, the external sawtooth structure 100 may be separated from the block 300. That is, in order to extend an actual lifespan of the block 300 product, a fixing force of the external sawtooth structure 100 should be reinforced. Methods of constructing the fixing force-reinforcing unit may include a method of reinforcing a fixing force using the structure of the external sawtooth structure 100, a method of reinforcing a fixing force using the structure of the block 300 to which the external sawtooth structure 100 is mounted, a method of reinforcing a fixing force using both of the structures, a method of using an adhesive or other materials for reinforcing adhesion, and the like. [76] Referring to FIG. 13, the present disclosure may provide a structure that a stepped portion 140 is formed on the external sawtooth structure 100 as the method of reinforcing the fixing force using the structure of the external sawtooth structure 100. A fixing force-reinforcing unit for reinforcing a fixing force onto the block 300 as a target, to which the external sawtooth structure 100 is fixed, may further be formed on a lower circumferential portion of the external sawtooth structure 100. The fixing force-reinforcing unit may include a stepped portion 140 with at least one step, formed on the circumferential portion. Preferably, the stepped portion 140 may include at least a portion which has a radius greater than a radius of the external sawtooth 17/31 structure 100. [77] The stepped portion 140 may preferably include a portion having at least two types of radiuses, in terms of further reinforcing the coupling force. The stepped portion 140 may include a first stepped portion 141 and at least one second stepped portion 142. The maximum radius of the first stepped portion 141 may be greater than the maximum radius of the second stepped portion 142. The first stepped portion 141 may be closer to the surface sawtooth portion 120 of the external sawtooth structure than the second stepped portion 142. A ratio that the radius is narrowed (or reduced) when the first stepped portion 141 is getting farther away from the surface sawtooth portion 120 of the external sawtooth structure may preferably be greater than a ratio that the radius is narrowed when the second stepped portion 142 is getting farther away from the surface sawtooth portion 120 of the external sawtooth structure. [78] Of course, the block 300 to which the external sawtooth structure 100 is mounted may preferably be provided with a step structure for effectively housing the single or double-stepped portion. The step structure of the block 300 may preferably be formed in an opposite shape to that of the stepped portion 140 formed on the external sawtooth structure 100. The step structure of the block 300 may effectively prevent the separation of the external sawtooth structure 100. [79] Referring to FIG. 14, the sawtooth structure 10 disclosed herein may be used for a toy block 300 which is made of plastic or other non-magnetic materials. The toy block 300 may be polyhedral, and the sawtooth structure 10 may be mounted to at least one of plural surfaces of the polyhedron. The polyhedron may essentially include at least one flat surface and selectively include at least one curved surface. [80] In the meantime, FIG. 15 is a sectional view illustrating an assembled state of toy blocks with a magnet-inserting structure in accordance with another exemplary embodiment disclosed herein. FIG. 16 illustrates an assembled structure of a sawtooth structure according to one exemplary embodiment of FIG. 15. FIG. 17 is an exploded perspective view of the sawtooth structure of FIG. 16. FIG. 18 is a longitudinal sectional view of FIG. 16. FIG. 19 is a sectional view taken along the line 'I-I' of FIG. 18. FIG. 20 is a longitudinal sectional view of a sawtooth structure in accordance with another exemplary embodiment disclosed herein. [81] As illustrated in those drawings, a sawtooth structure in accordance with an exemplary 18/31 embodiment may be provided together with a magnet 400 disposed in each magnet accommodating groove 21, which is formed on a plurality of positions of a toy block 20, thereby providing a coupling force such that the toy blocks can be assembled with each other. The sawtooth structure may include an external sawtooth structure 500 and an internal sawtooth structure 600. The external sawtooth structure 500 may include an opening formed on one side surface thereof, and a through hole 510 formed through another surface, facing the one side surface, to externally expose the magnet 400. The external sawtooth structure 500 may be inserted into the magnet accommodating groove 21 to come in contact with an inner surface of the magnet accommodating groove 21. The internal sawtooth structure 600 may be disposed within the external sawtooth structure 500 to be movable along a height direction of the external sawtooth structure 500. When the toy blocks are assembled with each other, a part of an upper end of the internal sawtooth structure 600 may externally protrude through the through hole 510. A separation-preventing portion 610 for maintaining the accommodated state of the magnet within the magnet accommodating groove 21 may be provided on one side of the internal sawtooth structure 600. [82] The toy block 20 which can be assembled with other toy blocks by the magnet 400 may have any shape if it has a polyhedral structure with a polygonal section, but this exemplary embodiment disclosed herein may provide the toy block in a cubic shape. [83] One magnet accommodating groove 21 may be formed on each of four outer surfaces of the toy block 20, and the magnet 400 may be accommodated therein. [84] The arrangement of the magnet accommodating grooves 21 in the four directions may enable a toy to be assembled both in a vertical direction and in a horizontal direction, and enhance the degree of freedom for assembly directions of the toy. [85] Depth and diameter of the magnet accommodating groove 21 may preferably be decided large enough for the magnet 40 accommodated therein to be rotatable in various directions. A stopping recess 21a may be formed on an inner wall of one side of the magnet accommodating groove 21 such that the external sawtooth structure 500 can be maintained in the inserted state in the magnet accommodating groove 21. [86] The magnet 400 may be formed in a cylindrical shape and accommodated in the magnet 19/31 accommodating groove 21. In order to enhance a coupling force between the magnets, an edge of the magnet 400 may be chamfered so as to come in contact directly with a magnet included in a neighboring toy block. [87] As the edge is rounded or chamfered, a part of the magnet 400 may be externally exposed through the through hole 510 so as to come in contact directly with the neighboring magnet, and be prevented from being separated from the magnet accommodating groove 21 by the separation-preventing portion 610. [88] The external sawtooth structure 500 may be inserted into the magnet accommodating groove 21 in a manner that a side surface thereof comes in contact with the magnet accommodating groove 21, so as to prevent the internal sawtooth structure 600 disposed in the external sawtooth structure 500 from being externally separated. [89] One side surface of the external sawtooth structure 500 may be provided with an opening through which the internal sawtooth structure 600 is inserted into the external sawtooth structure 500. The through hole 510 through which the magnet 400 is externally exposed may be formed through another side surface which is facing the one side surface. [90] The through hole 510 may preferably have a relatively smaller diameter than the magnet 400 such that the magnet 400 accommodated in the magnet accommodating groove 21 cannot be separated out of the magnet accommodating groove 21. [91] A bent portion 520 which is formed by bending a plate surface of the external sawtooth structure 500 may be formed on the external sawtooth structure 500 at a circumferential portion of the through hole 510. The bent portion 520 may come in contact with a stopping portion 630 of the internal sawtooth structure 600 so as to prevent the internal sawtooth structure 600 from being externally separated from the external sawtooth structure 500. [92] An inner sawtooth 521 of the external sawtooth structure may be formed on a lower surface of the bent portion 530 which contacts the stopping portion 630. [93] A stopping protrusion 530 may protrude from an outer surface of the external sawtooth structure 500 in a diameter direction of the external sawtooth structure 500. The stopping protrusion 530 may be coupled to the stopping recess 21a of the magnet accommodating groove 21 so as to prevent the external sawtooth structure 500 from being separated from the magnet 20/31 accommodating groove 21. [94] A bent surface 531 having a double-tilt angle may be formed on an outer surface of the stopping protrusion 530 such that the external sawtooth structure 500 can be smoothly inserted into the magnet accommodating groove 21 at the insertion operation. [95] The internal sawtooth structure 600 may be disposed in the external sawtooth structure 500 and selectively moved up and down along a height direction of the external sawtooth structure 500 according to whether or not the toy block 20 is assembled. [96] The separation-preventing portion 610 may separately provided on one side of the internal sawtooth structure 600 to prevent the magnet 400 disposed in the internal sawtooth structure 600 from being externally separated from the magnet accommodating groove 21. The separation-preventing portion 610 may include a separation-preventing jaw 611 whose lower surface is bent into a shape corresponding to the edge of the magnet 400 and which is formed on an inner wall of an upper portion of the internal sawtooth structure 600 to protrude by a predetermined length along a radial direction of the internal sawtooth structure 600. [97] As the lower surface of the separation-preventing jaw 611 is bent into the shape corresponding to the edge of the magnet 400, when the toy blocks are assembled with each other, the part of each magnet may be externally exposed to come in contact with a neighboring magnet, thereby enhancing the coupling force (assembling force) between the toy blocks. [98] An upper surface of the internal sawtooth structure 600 may be shown, having a protrusion 620 externally protruding through the through hole 510 when the toy blocks are assembled with each other, and the stopping portion 630 engaged with the bent portion 520 of the external sawtooth structure 500. [99] A lower surface of the bent portion 520 contacting the stopping portion 630 may be shown, having inner sawteeth 521 of the external sawtooth structure in the shape of sawtooth. An upper surface of the stopping portion 630 may be shown, having outer sawteeth 631 of the internal sawtooth structure 600 to be engaged with the inner sawteeth 521 of the external sawtooth structure 500. [100] The inner sawteeth 521 of the external sawtooth structure and the outer sawteeth 631 of the internal sawtooth structure may be engaged with each other when the toy blocks are 21/31 assembled with each other. The formation of the inner sawtooth of the external sawtooth structure and the outer sawtooth 631 of the internal sawtooth structure may allow children to assemble the toy blocks with accurately rotating them by a desired angle. [101] An upper surface of the protrusion 620 may be shown, having protrusion sawteeth 621, which are engaged with protrusion sawteeth 621 formed on a neighboring protrusion 620 when the toy blocks 20 are assembled with each other. [102] Similar to the inner sawteeth 521 of the external sawtooth structure and the outer sawteeth 631 of the internal sawtooth structure, the protrusion sawteeth 621 may also be engaged with the neighboring protrusion sawteeth 631 upon assembling the toy blocks with each other. This may allow children to assembly the toy blocks with accurately rotating the toy blocks by a desired angle. [103] The outer sawtooth 631 of the internal sawtooth structure and the protrusion sawtooth 621 may preferably be arranged in a radial direction in an alternating manner to prevent them from overlapping each other. [104] This may result in finely adjusting a desired angle when the toy blocks are assembled with each other. Simultaneously, a sound like 'click' may be generated more frequently when rotating the toy blocks in the assembled state, such that the children can be more excited when assembling the toy blocks. [105] An overturn-preventing portion 640 may be provided on one side of the internal sawtooth structure 600. By the formation of the overturn-preventing portion 640, the internal sawtooth structure 600 may be prevented from being fallen over and overturned within the external sawtooth structure 500. [106] The overturn-preventing portion 640 may be implemented as an extending member 641, which extends from a lower end of the internal sawtooth structure 600 by a predetermined length along a height direction such that the outer surface of the internal sawtooth structure 600 contacting the inner surface of the external sawtooth structure 500 can be higher than a predetermined height. [107] The extending member 641 may allow the height of the outer surface of the internal sawtooth structure 600 to be higher than a height of the inner surface of the external sawtooth 22/31 structure 500 by a predetermined height. Accordingly, the internal sawtooth structure 600 located within the external sawtooth structure 500 can be prevented from being overturned due to being inclined to one side upon being moved up and down within the external sawtooth structure 500. [108] A guide slit 641a may be formed on an inner surface of the extending member 641 in a curved manner so as to guide a movement of the magnet 400 when one surface of the magnet 400 accommodated in the magnet accommodating groove is externally exposed through the through hole 510. [109] The guide slit 641a may be curved upward from a lower surface of the extending member 641 toward the through hole 510 of the external sawtooth structure 500. Accordingly, when the toy blocks are assembled with each other, one side surface of the magnet 400 may be slid along the guide slit 641a to be externally exposed through the through hole 510. [110] Hereinafter, description will be given of a process of assembling toy blocks having the sawtooth structure according to the one exemplary embodiment having such configuration. [111] For assembling the toy blocks 20 with each other, when the toy blocks 20 are close to each other in distance, a side surface of the magnet 400 may be slid along the guide slit 641a formed in the extending member 641. Then, an edge of the magnet 400 may come in contact with the separation-preventing jaw 611 provided on the upper side of the internal sawtooth structure 600. [112] As the toy blocks are closer to each other, the magnet 400 may push up the internal sawtooth structure 300 by virtue of an attractive force between the magnets 400. The protrusion 620 of the internal sawtooth structure 600 may then be externally protruded through the through hole 510 of the external sawtooth structure 500 and the internal sawteeth 521 of the external sawtooth structure may be engaged with the outer sawteeth 631 of the internal sawtooth structure. [113] When the toy blocks 20 are fully closely adhered to each other, one side surface of the magnet 400 may be externally exposed through the through hole 510 of the external sawtooth structure 500 and accordingly, the magnet 400 may be coupled to the neighboring magnet 400 such that the toy blocks can be assembled with each other. Here, the protrusion sawteeth 621 may be engaged with the protrusion sawteeth of the neighboring toy block. [114] In this state, when the toy block 20 is rotated, the toy block 20 may be rotated, with 23/31 generating a sound 'click' due to the engagement between the inner sawtooth 521 of the external sawtooth structure and the outer sawtooth 631 of the internal sawtooth structure and between the protrusion sawtooth 621 and the neighboring protrusion sawtooth. A child can thus assemble the toy blocks 20 by a desired angle while hearing the sound. [115] FIG. 20 is a longitudinal sectional view of a sawtooth structure in accordance with another exemplary embodiment disclosed herein. The same/like components as those of the sawtooth structure according to the foregoing embodiment will be given with the same reference numerals, and detailed description thereof will be omitted. [116] As illustrated in FIG. 20, in a sawtooth structure according to another exemplary embodiment disclosed herein, the inner sawtooth 521 of the external sawtooth structure and the outer sawtooth 631 of the internal sawtooth structure may be upwardly inclined toward the through hole 510. [117] The inclined structure may facilitate the engagement between the inner sawtooth 521 of the external sawtooth structure and the outer sawtooth 631 of the internal sawtooth structure. Also, when the toy blocks are rotated after assembled, a move width of the internal sawtooth structure 600 in up and down directions may be reduced, resulting in a smooth rotation. [118] Referring to an example of FIG. 21, the sawtooth structure 20 according to the present disclosure is generally mounted to at least one of flat surfaces of the polyhedron, but the sawtooth structure 10 may also be mounted to a curved surface on a special occasion. [119] As exemplarily illustrated in FIG. 22, upon utilizing the present disclosure, the sawtooth structure 10 according to the present disclosure may be provided between two blocks 300, allowing an assembly angle to be finely adjusted for accurate assembling or desired assembling of the blocks 300. Therefore, as illustrated in FIG. 23, the plurality of various blocks 300 each having the sawtooth structure 10 according to the present disclosure may be provided. Upon assembling the blocks 300, a toy set whose assembly angle can be finely adjusted may also be produced.

Claims (34)

1. A sawtooth structure capable of being mounted to a toy block, the sawtooth structure comprising: an external sawtooth structure; and an internal sawtooth structure, wherein an inner sawtooth portion having at least two inner sawteeth is formed on at least a part of an inner surface of the external sawtooth structure, and wherein an outer sawtooth portion having at least two outer sawteeth is formed on at least a part of an outer surface of the internal sawtooth structure to correspond to the inner sawtooth portion of the external sawtooth structure.

2. The sawtooth structure of claim 1, wherein the inner sawtooth portion of the external sawtooth structure is formed on the inner surface of the external sawtooth structure, wherein the outer sawtooth portion of the internal sawtooth structure is formed on the outer surface of the internal sawtooth structure, wherein the inner sawtooth portion of the external sawtooth structure is divided into an inner sawtooth area and an inner non-sawtooth area, and wherein the outer sawtooth portion of the internal sawtooth structure is divided into an outer sawtooth area and an outer non-sawtooth area.

3. The sawtooth structure of claim 2, wherein a flat area of the inner surface occupied by the inner non-sawtooth area of the external sawtooth structure is greater than a flat area of the inner surface occupied by the inner sawtooth area of the external sawtooth structure by more than a predetermined ratio, and wherein a flat area of the outer surface occupied by the outer non-sawtooth area of the internal sawtooth structure is greater than a flat area of the outer surface occupied by the outer sawtooth area of the internal sawtooth structure by more than the predetermined ratio. 25/31

4. The sawtooth structure of claim 3, wherein the predetermined ratio is greater than 1 and smaller than 10.

5. The sawtooth structure of claim 1, wherein the internal sawtooth structure is spaced from the external sawtooth structure so as to be rotatable in the external sawtooth structure, and wherein the outer sawtooth area of the outer sawtooth portion of the internal sawtooth structure goes over the inner sawtooth area of the inner sawtooth portion of the external sawtooth structure.

6. The sawtooth structure of claim 3, wherein the number of inner sawteeth constructing the inner sawtooth portion of the external sawtooth structure and the number of inner sawteeth constructing the outer sawtooth portion of the internal sawtooth structure are in a ratio of 1:1.

7. The sawtooth structure of claim 3, wherein the number of inner sawteeth constructing the inner sawtooth portion of the external sawtooth structure and the number of outer sawteeth constructing the outer sawtooth portion of the internal sawtooth structure are in a ratio of 1:n or 1:1/n (n=natural number more than 2 and less than 4), wherein the outer non-sawtooth area of the internal sawtooth structure is sufficiently greater than the outer sawtooth area of the internal sawtooth structure, such that at least two inner sawteeth of the external sawtooth structure can enter between the outer sawteeth of the internal sawtooth structure, when the number of inner sawteeth of the external sawtooth structure is greater than the number of outer sawteeth of the internal sawtooth structure, and wherein the inner non-sawtooth area of the external sawtooth structure is sufficiently greater than the inner sawtooth area of the external sawtooth structure, such that at least two outer sawteeth of the inner sawtooth structure can enter between the inner sawteeth of the external sawtooth structure, when the number of the outer sawteeth of the internal sawtooth structure is greater than the number of inner sawteeth of the external sawtooth structure.

8. The sawtooth structure of claim 1, wherein at least one of the inner sawtooth of the 26/31 external sawtooth structure or the outer sawtooth of the internal sawtooth structure has a symmetric shape in left and right directions.

9. The sawtooth structure of claim 1, wherein at least one of the inner sawtooth of the external sawtooth structure or the outer sawtooth of the internal sawtooth structure has an asymmetric shape in the left and right directions.

10. The sawtooth structure of claim 9, wherein when both the inner sawtooth of the external sawtooth structure and the outer sawtooth of the internal sawtooth structure have the asymmetric shape in the left and right directions, the inner sawteeth of the external and internal and the outer sawteeth of the internal sawtooth structure are arranged in such a manner of minimizing rotation resistance in one direction and maximizing rotation resistance in an opposite direction.

11. The sawtooth structure of claim 1, wherein the external sawtooth structure further comprises a surface sawtooth portion having at least two surface sawteeth or the internal sawtooth structure further comprises a surface sawtooth portion having at least two surface sawteeth.

12. The sawtooth structure of claim 11, wherein the number of inner sawteeth of the external sawtooth structure and the number of surface sawteeth of the external sawtooth structure are the same as each other, and wherein the inner sawteeth and the surface sawteeth of the external sawtooth structure are arranged by a first arrangement method of arranging the inner sawtooth and the surface sawtooth of the external sawtooth structure on the same position, and a second arrangement method of arranging the surface sawtooth of the external sawtooth structure between the inner sawteeth of the external sawtooth structure.

13. The sawtooth structure of claim 11, wherein the number of inner sawteeth of the 27/31 external sawtooth structure and the number of surface sawteeth of the external sawtooth structure are different from each other, and wherein the inner sawteeth and the surface sawteeth are arranged in a manner of arranging the surface sawtooth between the inner sawteeth.

14. The sawtooth structure of claim 11, wherein the number of outer sawteeth of the internal sawtooth structure is the same as or greater than the number of surface sawteeth of the internal sawtooth structure.

15. The sawtooth structure of claim 1, wherein the internal sawtooth structure has a shape of a cone with an upper portion cut off, and is provided with a space having a magnet accommodating portion of more than a predetermined size for accommodating at least one magnet therein.

16. The sawtooth structure of claim 1, wherein the internal sawtooth structure is completely accommodated in the external sawtooth structure, and wherein a stopping jaw is formed on a lower portion of the inner surface of the external sawtooth structure, so as to prevent separation of the internal sawtooth structure to outside when the internal sawtooth structure is accommodated in the external sawtooth structure.

17. The sawtooth structure of claim 1, wherein the external sawtooth structure has a cylindrical outer shape which is wide in width and long in length, and wherein an inner shape of the external sawtooth structure comprises an accommodating space of the internal sawtooth structure for accommodating the internal sawtooth structure therein.

18. The sawtooth structure of claim 1, further comprising a fixing force-reinforcing unit formed on a lower circumferential portion of the external sawtooth structure to fix the external sawtooth structure to a block. 28/31

19. The sawtooth structure of claim 18, wherein the fixing force-reinforcing unit comprises a stepped portion having at least one step, formed along the circumferential portion, wherein at least a part of the stepped portion is provided with a portion having a radius greater than a radius of the external sawtooth structure, and wherein the stepped portion comprises a portion having at least two types of radiuses.

20. The sawtooth structure of claim 19, wherein the stepped portion comprises a first stepped portion and at least one second stepped portion, wherein the maximum radius of the first stepped portion is greater than that of the second stepped portion, wherein the first stepped portion is arranged closer to the surface sawtooth portion of the external sawtooth structure than the second stepped portion, and wherein a ratio that the radius of the first stepped portion is reduced when the first stepped portion is getting away from the surface sawtooth portion of the external sawtooth structure is greater than a ratio that the radius of the second stepped portion is reduced when the second stepped portion is getting away from the surface sawtooth portion of the external sawtooth structure.

21. The sawtooth structure of claim 1, wherein the sawtooth structure is accommodated, together with a magnet, in each of magnet accommodating grooves formed on a plurality of positions of a toy block, wherein the external sawtooth structure comprises an opening formed on one side surface thereof, and a through hole formed through another side surface, facing the one side surface, for externally exposing the magnet therethrough, wherein the external sawtooth structure is inserted in the magnet accommodating groove in a contact state with an inner surface of the magnet accommodating groove, and wherein the internal sawtooth structure is arranged within the external sawtooth structure to be movable along a height direction of the external sawtooth structure, and has a part of an upper end thereof externally protruding through the through hole when the toy blocks are 29/31 assembled with each other, the internal sawtooth structure comprising a separation-preventing portion formed on one side thereof to prevent the magnet from being separated from the magnet accommodating portion.

22. The sawtooth structure of claim 21, wherein a bent portion is formed on a circumferential portion of the through hole formed on the external sawtooth structure in a bent manner, and wherein a protruding portion externally protruding through the through hole when the toy blocks are assembled with each other, and a stopping portion stopped at the bent portion are formed on an upper surface of the internal sawtooth structure.

23. The sawtooth structure of claim 22, wherein inner sawteeth of the external sawtooth structure in a shape of sawtooth are formed on a lower surface of the bent portion contactable with the stopping portion, wherein outer sawteeth of the internal sawtooth structure engaged with the inner sawteeth of the external sawtooth structure are formed on an upper surface of the stopping portion, and wherein protrusion sawteeth, engaged with protrusion sawteeth formed on a neighboring protruding portion when the toy blocks are assembled with each other, are formed on an upper surface of the protruding portion.

24. The sawtooth structure of claim 23, wherein the outer sawteeth and the protrusion sawteeth of the internal sawtooth structure are arranged along a radial direction in an alternating manner to prevent mutual overlapping.

25. The sawtooth structure of claim 21, wherein an overturn-preventing portion is formed on one side of the internal sawtooth structure, so as to prevent the internal sawtooth structure from being overturned within the external sawtooth structure.

26. The sawtooth structure of claim 25, wherein the overturn-preventing portion is 30/31 implemented as an extending member, which extends from a lower portion of the internal sawtooth structure by a predetermined length along a height direction of the internal sawtooth structure, such that the outer surface of the internal sawtooth structure contacting the inner surface of the external sawtooth structure is higher than a predetermined height.

27. The sawtooth structure of claim 26, wherein a guide slit is formed in a curved manner on the inner surface of the extending member, the guide slit guiding a movement of the magnet when one surface of the magnet accommodated in the magnet accommodating groove is externally exposed through the through hole.

28. The sawtooth structure of claim 21, wherein an edge of the magnet is inclined or rounded, wherein the separation-preventing portion has a lower surface curved into a shape corresponding to the edge of the magnet, and wherein the separation-preventing portion is implemented as a separation-preventing jaw protruding from an inner wall of an upper portion of the internal sawtooth structure along a radial direction of the internal sawtooth structure.

29. The sawtooth structure of claim 28, wherein a stopping recess is recessed into an inner surface of the magnet accommodating groove of the block, and wherein a stopping protrusion inserted into the stopping recess is provided on one side of the outer surface of the external sawtooth structure such that the external sawtooth structure is maintained in the inserted state in the magnet accommodating groove.

30. The sawtooth structure of claim 29, wherein a double-curved surface is formed on an outer surface of the stopping protrusion, the double-curved surface facilitating an insertion of the external sawtooth structure into the magnet accommodating groove.

31. The sawtooth structure of claim 23, wherein an inter-contact surface between the 31/31 external sawtooth structure and the internal sawtooth structure having the inner sawteeth and the outer sawteeth, respectively, is upwardly inclined toward the through hole.

32. A toy block comprising the sawtooth structure according to one of claims 1 to 31.

33. The toy block of claim 32, wherein the toy block is polyhedral, and the sawtooth structure is mounted to at least one of a plurality of surfaces constructing the polyhedron.

34. The toy block of claim 33, wherein the polyhedron essentially comprises at least one flat surface, and selectively comprises at least one curved surface.