Danjiri top

Abstract

To provide a top that allows a danjiri to run easily. [Solution] The top comprises a core 10 and an annular outer peripheral portion 11 attached to the outer peripheral surface of the core 10 and in contact with the ground; the core 10 is polygonal prism-shaped, and the outer peripheral surface of the core 10 is composed of a plurality of outer flat portions 20 corresponding to the sides of the polygon; the outer peripheral portion 11 has a bottom surface that is respectively joined to the plurality of outer flat portions 20 of the core 10 and is composed of a plurality of block bodies 50 arranged circumferentially of the core 10; the groove is rectangular in cross section and is formed in the outer flat portion 20 of the core 10; the inertia member 30 is a square bar that is rectangular in cross section corresponding to the groove and engages with the groove so as to be flush with the outer flat portion 20.

Description

[Technical Field]

[0001] This invention relates to a danjiri top. [Background technology]

[0002] The wheels of a danjiri float are called koma. Koma are generally made of wood, such as pine, but recently, as in Patent Documents 1 and 2 below, laminated wood has also been used. Attempts have also been made to reduce rolling resistance, such as by using bearings for the axles, but with the decline in the number of people pulling the floats, further evolution of koma is required. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3156080 [Patent Document 2] Utility Model Registration No. 3187763 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of this invention is to provide a top that allows the danjiri to run easily. [Means for solving the problem]

[0005] The danjiri top of this invention is equipped with an inertia member made of lead.

[0006] With this configuration, the inertia member made of lead increases the moment of inertia of the top, so once the danjiri starts moving, the top's rotation is less likely to slow down, and the puller can continue to move the danjiri without having to continue pulling it with great force.

[0007] In particular, it is preferable that the scooter comprises a core and an annular outer peripheral portion attached to the outer peripheral surface of the core and in contact with the ground, and that the inertia member be provided on the outer peripheral surface of the core. In this configuration, with the outer peripheral portion attached to the outer peripheral surface of the core, the core can be reused, for example, after one year of use, by removing the outer peripheral portion of the used link by scraping or the like, and then attaching a new outer peripheral portion to the outer peripheral surface of the core. In other words, the link can be regenerated. Furthermore, by attaching the inertia member to the outer peripheral surface of the core, the inertia member can be reused together with the core. Furthermore, because the inertia member is located on the outer peripheral surface of the core, i.e., the radially outermost portion of the core, the inertia member effectively exhibits its function of increasing the moment of inertia.

[0008] Furthermore, it is preferable that a groove extending along the axial direction of the core is formed on the outer peripheral surface of the core across the entire width of the core, and that the inertia member is rod-shaped and extends axially in the core and is attached to the groove. With this configuration, by attaching the inertia member to the groove, the inertia member does not get in the way when attaching the outer peripheral portion to the outer peripheral surface of the core. Furthermore, the inertia member does not get in the way when remaking the top, allowing for efficient work. Moreover, since the groove extends along the axial direction of the core and is formed across the entire width of the core, the groove can be easily formed in the core. Furthermore, since the grooves open on both side surfaces of the core, which are both axial end surfaces of the core, the inertia member can be seen through the side openings of the groove. In other words, the inertia member's appearance on the top gives the puller the impression of a "running top," resulting in a highly aesthetic design.

[0009] Furthermore, the core is preferably polygonal prism-shaped, the outer peripheral surface of the core being composed of a plurality of outer flat sections corresponding to the sides of the polygon, the outer peripheral section being composed of a plurality of block bodies arranged circumferentially of the core, each having a bottom surface joined to the plurality of outer flat sections of the core, the groove being rectangular in cross section and formed in the outer flat section of the core, and the inertia member being a square bar having a rectangular cross section corresponding to the groove and engaging with the groove so as to be flush with the outer flat section. According to this configuration, the inertia member being a square bar improves the ease of attachment to the groove and stability compared to a round bar. Therefore, the generation of vibrations and abnormal noises from the inertia member during running is suppressed. Moreover, because one side of the square bar inertia member is flush with the outer flat section of the core, the bottom surface of the block body can be firmly attached to the outer flat section of the core. Furthermore, the inertia member is radially sandwiched between the block body and the core, further stabilizing the inertia member. [Effects of the Invention]

[0010] As described above, the inertia member made of lead increases the moment of inertia of the top, allowing the danjiri to continue running more easily and reducing the burden on the pullers. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a front view of the side of a danjiri top according to one embodiment of the present invention, viewed in the axial direction. [Figure 2] Cross-section of the same frame. [Figure 3] Cross-section of the same frame. [Figure 4] An exploded view of the same frame. [Figure 5] FIG. [Figure 6] FIG. 10 is a front view of a danjiri top according to another embodiment of the present invention, viewed in the axial direction. DETAILED DESCRIPTION OF THE INVENTION

[0012] A danjiri top according to one embodiment of the present invention will be described below with reference to the drawings. Figures 1 to 5 show the top of this embodiment. The danjiri is provided with a total of four tops as wheels, one each at the front, rear, left and right. The tops are made of wood. The tops are installed so as to be rotatable relative to the danjiri's axle. A through-hole 1 is formed in the center of the top, penetrating in the axial direction. As shown in Figure 5, a bearing 2 is inserted into the through-hole 1 of the top. The bearing 2 is made of metal and is also called a gutter. The bearing 2 is detachably attached to the top with a bolt and nut. The axle passes through the bearing 2, and the bearing 2 rotates integrally with the top relative to the axle.

[0013] The bearing 2 has a bearing tubular portion 2a and a bearing flange portion 2b that protrudes radially outward from one end of the bearing tubular portion 2a. The axle is inserted radially inside the bearing tubular portion 2a. The outer surface of the bearing tubular portion 2a is tapered, decreasing in diameter toward the other end of the bearing tubular portion 2a, and the inner surface of the through-hole 1 in the bearing block is correspondingly tapered. The bearing flange portion 2b is square when viewed axially, and four bolts are inserted axially into its four corners. A square recess 3 is formed in the center of one side of the bearing block, and the bearing flange portion 2b fits into the recess 3 of the bearing block.

[0014] The top consists of a core 10 having a through hole 1, and an annular outer periphery 11 attached to the outer periphery of the core 10 and in contact with the ground. The core 10 is preferably made of zelkova, and the outer periphery 11 is preferably made of pine. By making the core 10 out of zelkova, it can be made harder and stronger than the outer periphery 11. The core 10 of the top is reusable, and its durability is improved, allowing it to be reused more frequently. On the other hand, by making the outer periphery 11 out of pine, it provides better cushioning, improving the running and operability of the danjiri. When recycling the top, the used outer periphery 11 is removed, and a new outer periphery 11 is attached to the core 10. Both the core 10 and the outer periphery 11 are preferably made of laminated wood.

[0015] The core portion 10 has a polygonal prism shape. Both side surfaces, which are both axial end surfaces of the core portion 10, are polygonal, more specifically, regular polygons, and in this embodiment, a regular dodecagon. Therefore, the outer peripheral surface of the core portion 10 is composed of a plurality of outer flat surfaces 20, and in this embodiment, it is composed of 12 outer flat surfaces 20. In other words, an outer flat surface 20 is provided corresponding to each side of the polygon, and the number of outer flat surfaces 20 matches the number of sides of the polygon. All of the outer flat surfaces 20 have the same shape. However, the side surfaces of the core portion 10 may be polygons that are not regular polygons, and all of the outer flat surfaces 20 do not have to have the same shape.

[0016] A groove 21 is formed in a predetermined outer flat portion 20. The groove 21 opens radially outward and also opens to both side surfaces of the core portion 10. That is, the groove 21 is formed across the entire axial length (full width) of the core portion 10. The cross-sectional shape of the groove 21 is rectangular, typically a rectangle or a square, and in this embodiment, it is a square. The groove 21 is formed in the circumferential center of the outer flat portion 20. The groove 21 is formed in a plurality of the 12 outer flat portions 20, and in this embodiment, it is formed in four outer flat portions 20. The grooves 21 are arranged at equal intervals in the circumferential direction. Therefore, the four grooves 21 are arranged every 90 degrees.

[0017] An inertia member 30 is attached to the groove 21. The inertia member 30 is a square rod that corresponds to the cross-sectional shape of the groove 21 and is square. The inertia member 30 engages with the groove 21. Three of the four side surfaces of the inertia member 30 face the bottom surface and both wall surfaces of the groove 21. The remaining side surface of the inertia member 30 faces radially outward and is flush with the outer flat surface portion 20. Furthermore, both axial end surfaces of the inertia member 30 are flush with both side surfaces of the core portion 10 and are exposed at both side surfaces of the core portion 10. The overall length of the inertia member 30 is equal to the overall axial length (total width) of the core portion 10.

[0018] The inertia members 30 are made of lead and are constructed from square lead rods. All four inertia members 30 are formed in the same shape, and their arrangement, together with the positioning of the inertia members, ensures balance during rotation of the top. The inertia members 30 are glued to the bottom and both wall surfaces of the groove 21. The inertia members 30 also have a total of three radially penetrating mounting holes 31 formed at axial intervals. Of the three mounting holes 31, two at both ends have counterbore holes 58 for screws. The inertia members 30 are fastened to the core 10 by third mounting screws 43 through the two mounting holes 31 at both ends. The heads of the third mounting screws 43 fit into the counterbore holes 58 for screws. Therefore, the heads of the third mounting screws 43 do not protrude radially outward from the side surfaces of the inertia members 30. When the top is regenerated, the inertia member 30 is reused together with the core 10 without being removed from the core 10.

[0019] The outer peripheral portion 11 is composed of a plurality of block bodies 50. The plurality of block bodies 50 are arranged in a circumferential direction to form a ring. The number of block bodies 50 corresponds to the polygonal shape of the core portion 10, i.e., 12 block bodies 50 are arranged. The block bodies 50 are each adhered to the outer flat portion 20 of the core portion 10. Adjacent block bodies 50 in the circumferential direction are also adhered and fixed to each other.

[0020] The block body 50 has an outer peripheral curved surface 51 constituting the outer peripheral surface of the outer peripheral portion 11, a bottom surface 52 radially opposed to the outer peripheral curved surface 51, a front surface 53 and a rear surface 54 circumferentially opposed to each other, and a pair of side surfaces 55 axially opposed to each other. The bottom surface 52 is flat and shaped to correspond to the outer flat surface 20, and is bonded to the outer flat surface 20. The front surface 53 and the rear surface 54 are both flat. The circumferential dimension of the block body 50, i.e., the distance between the front surface 53 and the rear surface 54, gradually increases from the bottom surface 52 toward the outer peripheral curved surface 51. The front surface 53 is perpendicular to the bottom surface 52, and the rear surface 54 connects to the bottom surface 52 at an obtuse angle exceeding 90 degrees. Due to the inclination of the rear surface 54, the circumferential dimension of the block body 50 gradually increases radially outward. When attached to the danjiri, the front surface 53 is located at the front of the danjiri in the direction of rotation, and the rear surface 54 is located at the rear of the danjiri in the direction of rotation. That is, the top has a directionality in the rotation direction. The outer circumferential curved surface 51 is curved along the circumferential direction and serves as a contact surface that comes into contact with the ground.

[0021] The block body 50 is screwed to the core 10. A countersunk hole 56 is formed in the outer curved surface 51 of the block body 50 along the radial direction. The block body 50 is generally attached to the core 10 with a first mounting screw 41. The first mounting screw 41 is inserted into the countersunk hole 56. A filler 57 is attached to the countersunk hole 56. However, the four block bodies 50 attached to the four outer flat surfaces 20 on which the inertia members 30 are attached are attached to the core 10 with a second mounting screw 42 that is longer than the first mounting screw 41. The second mounting screw 42 penetrates the inertia member 30 in the radial direction. Specifically, the second mounting screw 42 is inserted through the central mounting hole 31 of the three mounting holes 31 of the inertia member 30.

[0022] As described above, the top in this embodiment is equipped with an inertia member 30 made of lead. Therefore, the moment of inertia is large, and once rotated, the rotational speed is unlikely to decrease. Therefore, when a danjiri equipped with this top is run, the top's rotation is unlikely to decrease. Once the danjiri starts running, the puller can continue to run the danjiri without having to continue pulling it with strong force, thereby reducing the puller's burden. Furthermore, since the inertia member 30 is located on the outer periphery of the core 10, the effect of equipping the inertia member 30 is maximized. Furthermore, when the inertia member 30 is attached to the outer periphery of the core 10, the inertia member 30 can be easily reused along with the core 10.

[0023] Furthermore, when the inertia member 30 is attached to the recessed groove 21, the inertia member 30 does not get in the way when attaching the outer peripheral portion 11 to the outer peripheral surface of the core portion 10, and the inertia member 30 does not get in the way when reusing the core portion 10. Furthermore, since the recessed groove 21 is aligned along the axial direction of the core portion 10 and is formed across the entire width of the core portion 10, the recessed groove 21 can be easily formed in the core portion 10. Furthermore, since the end faces of the inertia member 30 are exposed on both side surfaces of the core portion 10, the presence of the inertia member 30 can be easily visually confirmed from the outside, resulting in a good external design.

[0024] Furthermore, if the inertia member 30 is a square bar and engages with the recessed groove 21, the mounting state of the inertia member 30 is stable, and the generation of abnormal noise and the like can be suppressed. Furthermore, if the side surface of the inertia member 30 is flush with the outer flat surface 20 of the core 10, the bottom surface 52 of the block body 50 can be firmly mounted to the outer flat surface 20 of the core 10, and the inertia member 30 can be held by being sandwiched radially between the block body 50 and the core 10. This makes the mounting state of the inertia member 30 even more stable.

[0025] The number of inertia members 4 is arbitrary, and may be four as described above, or three at 120 degree intervals as shown in FIG. 6, or six. [Explanation of symbols]

[0026] 1 through hole 2 bearings 2a Bearing sleeve 2b Bearing flange 3 recess 10 core 11 Outer periphery 20 Outer flat section 21 Groove 30 Inertia member 31 Mounting hole 41 First mounting screw 42 Second mounting screw 43 Third mounting screw 50 Block Letters 51 Peripheral curved surface 52 bottom 53 Front 54 Rear 55 Side 56 Counterbore 57 Buried Wood 58 Counterbore for screws

Claims

1. A danjiri top equipped with an inertia member made of lead.

2. 2. The danjiri top according to claim 1, comprising a core portion and an annular outer periphery attached to the outer periphery of the core portion and in contact with the ground, and the inertia member is provided on the outer periphery of the core portion.

3. A danjiri top as described in claim 2, wherein a groove extending along the axial direction of the core is formed on the outer surface of the core across the entire width of the core, and the inertia member is rod-shaped extending in the axial direction of the core and is attached to the groove.

4. the core portion has a polygonal columnar shape, and the outer peripheral surface of the core portion is composed of a plurality of outer flat portions corresponding to the sides of the polygon; the outer peripheral portion has bottom surfaces joined to the outer flat portions of the core portion, respectively, and is composed of a plurality of block bodies arranged in a circumferential direction of the core portion; The groove has a rectangular cross section and is formed in the outer flat surface of the core.

4. The danjiri top according to claim 3, wherein the inertia member is a square bar having a rectangular cross section corresponding to the groove, and is engaged with the groove so as to be flush with the outer flat surface portion.

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