Patent Publication Number: US-9849395-B1

Title: Toy top

Description:
BACKGROUND 
     Field of the Invention 
     The present invention relates to a toy top. 
     Description of Related Art 
     Traditionally, there is suggested a toy top provided with a spherical body as a contact at the tip of the shaft unit thereof (for example, see Japanese Unexamined Utility Model Application Publication No. S55-45385). 
     In such case where the contact provided at the tip of the shaft unit is a spherical body, the friction resistance that occurs between the tip of the shaft unit and the field (the surface where the game takes place) can be decreased and the toy top can spin more smoothly. 
     In such toy top, as in the pointed tip of a ball-pointed pen, a ring member for supporting the spherical body by the section below the largest diameter section of the spherical body is provided so as to prevent the spherical body from falling downward. 
     However, in the case where the ring member is disposed around the spherical body, the shaft of the toy top may tilt due to the toy top being thrown in to the field in a diagonal direction or due to the toy top being bounced off by coming in contact with another toy top which is the toy top of the opponent of the battle game, for example, and the ring member may come in contact with the field. 
     If the ring member comes in contact with the field, the posture of the toy top whose shaft is tilted can be restored and a brake will be applied to the toy top preventing the toy top from flying out from the field. However, on the other hand, if the ring member is fixated, there is a problem that the rotational energy of the toy top will be lost due to the friction resistance that occurs between the ring member and the field being large. 
     Such problem is not limited to the case where the contact is a spherical body and such problem may similarly occur in cases where ring members are disposed around contacts regardless of the shapes of the tips of the contacts. 
     SUMMARY 
     The present invention is made in view of the above problem and an object is to provide a toy top having a configuration that can control the rotational energy loss while ensuring the brake performance. 
     According to an aspect of the present invention, there is provided a toy top, including: a shaft unit whose shaft center is an axis that matches a rotational center; and a shaft tip unit which is provided at a lower end section of the shaft unit, the shaft tip unit including a ring member provided in a movable manner centering around the axis and a member that comes in contact with a ground which is disposed at a center of the ring member and which protrudes downward than the ring member, wherein the shaft unit includes: a lower case which supports the shaft tip unit from below in a moveable manner and from which a lower end section of the shaft tip unit is exposed; and an abutting member which abuts an upper side of the shaft tip unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinbelow and the appended drawings, and thus are not intended to define the limits of the present invention, and wherein; 
         FIG. 1A  is a perspective view showing an embodiment of a toy top according to the present invention; 
         FIG. 1B  illustrates how to play with the toy top according to the embodiment; 
         FIG. 2  is an exploded perspective view of the toy top according to the embodiment; 
         FIG. 3A  is a cross-sectional perspective view where a shaft unit of the toy top of the embodiment is cut along the left-right direction; 
         FIG. 3B  is a cross-sectional perspective view where the shaft unit of the embodiment is cut along the front-rear direction; 
         FIG. 4  is an exploded perspective view of the shaft unit of the toy top; 
         FIG. 5A  is a perspective view of a pressing member of the toy top; 
         FIG. 5B  is a perspective view of a ring member of the toy top; 
         FIG. 5C  is a perspective view of the first pillar member of the toy top; 
         FIG. 5D  is a perspective view of a lower case of the toy top; 
         FIG. 6A  is a perspective view of a shaft unit main body of the toy top; 
         FIG. 6B  is a perspective view illustrating a state where the first pillar member is detached from the shaft unit main body shown in  FIG. 6A ; 
         FIG. 7A  is a cross-sectional perspective view of a performance changing ring (flywheel); 
         FIG. 7B  is a cross-sectional perspective view of a body; 
         FIGS. 8A and 8B  illustrate operation in a state where the shaft unit, body and performance changing ring (flywheel) which form the toy top main body of the toy top according to the embodiment are engaged to each other; and 
         FIG. 9  is a perspective view of an example of a launcher which drives and makes the toy top of the embodiment spin. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, an embodiment of the toy top according to the present invention will be described with reference to  FIGS. 1A and 1B  to  FIG. 9 . 
     Here, although various limitations which are technically preferable to carry out the present invention are described in the following embodiment, the invention is not limited to the embodiment and the examples shown in the drawings. 
     &lt;Overall Configuration&gt; 
       FIG. 1A  is a perspective view showing an embodiment of a toy top according to the present invention,  FIG. 1B  illustrates how to play with the toy top according to the embodiment, and  FIG. 2  is an exploded perspective view of the toy top according to the present invention. 
     Here, in the present description, the up and down directions, left and right directions and front and rear directions are the directions indicated in  FIG. 2 . 
     The toy top  1  of the embodiment is a toy top which can be used in a so-called toy top battle game. 
     Specifically, the toy top  1  can be used in a battle game where whoever makes the opponent&#39;s toy top  1  disassembled as shown in  FIG. 1B  by the impact force of the collision of the two toy tops is the winner of the game. 
     As shown in  FIGS. 1B and 2 , the toy top  1  includes a shaft unit  10  which forms the lower structure and which is the driver, a performance changing ring  30  and a body  40  which are layers that form the upper structure. 
     &lt;Detail Configuration&gt; 
     1. Shaft Unit  10   
       FIG. 3A  is a cross-sectional perspective view where the shaft unit of the toy top of the embodiment is cut along the left-right direction of  FIG. 2 , and  FIG. 3B  is a cross-sectional perspective view where the shaft unit of the toy top of the embodiment is cut along the front-rear direction of  FIG. 2 . 
     Further,  FIG. 4  is an exploded perspective view of the shaft unit of the embodiment. 
     As shown in  FIG. 2 , the shaft center of the shaft unit  10  is the axis which matches the rotation center of the toy top  1  and the shaft unit  10  includes a shaft tip unit  11  at the lower end section, a flange  12  at the center section in the up-down direction and a cylinder  13  at the upper section. 
     As shown in  FIG. 4 , the flange  12  and the cylinder  13  integrally form the upper case  14  and form the upper section of the shaft unit in the embodiment. 
     As shown in  FIGS. 3A and 4 , at the cylinder  13  and the flange  12  of the upper case  14 , protrusions  141  are respectively formed at two positions facing each other in the left-right direction having the axis of the shaft unit  10  therebetween. The outer surfaces of the protrusions  141  are substantially flat with relation to the outer surface of the flange  12 . 
     Further, as shown in  FIGS. 3B and 4 , at the cylinder  13  and the flange  12  of the upper case  14 , holes  142  are respectively formed at two positions facing each other in the front-rear direction having the axis of the shaft unit  10  therebetween. The holes  142  extend along the axis of the shaft unit  10 . 
     The shaft unit  10  further includes a pressing member  15  which is formed in an approximately cylinder shape. Although the pressing member  15  is made of synthetic resin in the embodiment, the pressing member  15  may be made of metal or the like. 
       FIG. 5A  is a perspective view when the pressing member  15  is looked down diagonally. 
     As shown, in  FIGS. 3B, 4 and 5A , the pressing member  15  includes a cylinder  151 , a ceiling  152  and legs  153 . 
     The outer diameter of the cylinder  151  is smaller than the inner diameter of the cylinder  13  of the upper case  14 , and the cylinder  151  of the pressing member  15  is disposed in the cylinder  13  of the upper case  14  when assembled. 
     Further, the inner diameter of the cylinder  151  is larger than the outer diameter of the upper end section of the after-mentioned first pillar member  53  of the shaft main body  50 , and the upper end section of the first pillar member  53  is fit in the cylinder  151 . 
     The ceiling  152  is formed at the upper end of the cylinder  151 . The ceiling  152  has a hole  154  having a shape that corresponds to the upper end section of the first pillar member  53  formed therein. 
     Further, the legs  153  are formed at the lower end section on the outer circumference of the cylinder  151 . 
     The legs  153  are formed at two positions on the outer circumference of the cylinder  151  that face each other in the front-rear direction having the axis of the shaft unit  10  therebetween. Each leg  153  includes a horizontal part  155  which protrude horizontally from the cylinder  151  and a vertical part  156  which extend vertically downward from the tip of the horizontal part  155 . 
     The pressing member  15  which is configured as described above is set so that the legs  153  are inserted in the holes  142  of the upper case  14  when assembled. The size of the holes  142  in the up-down direction is set to be larger than the length of the legs  153  and the legs  153  are respectively guided in the up and down directions in the holes  142  so that the pressing member  15  can move in the up and down directions along the axis of the shaft unit  10 . 
     The pressing member  15  is biased in the upper direction by a spring  16 . The pressing member  15  is restricted from moving upward due to the legs  153  abutting the upper edges of the holes  142  and in the normal state, the upper edge of the pressing member  15  is disposed at approximately the same height as the upper edge of the cylinder  13  of the upper case  14 . 
     Further, on the upper surface of the ceiling  152  of the pressing member  15 , ridges (protrusions)  157  which extend in the radius direction are formed at two positions that face each other in the left-right direction having the axis of the shaft unit  10  therebetween. 
     The lower section of the shaft unit  10  is provided with a lower case  17  which forms the lower section of the shaft unit, which supports the after-mentioned shaft tip unit  11  from below in a movable manner and from which the lower end part of the shaft tip unit  11  is exposed. 
       FIG. 5D  is a perspective view of the lower case  17  of the embodiment. 
     As shown in  FIGS. 4 and 5D , the upper end and the lower end of the lower case  17  which forms the lower section of the shaft unit are opened and the lower case  17  is formed in a shape where the diameter becomes gradually smaller as approaching the shaft tip unit  11  side from the flange  12  side. As a whole, the lower case  17  is formed in an approximately hemispherical shape or in an approximately reversed cone shape. 
     As shown in  FIGS. 2 and 4 , the lower case  17  has protrusions  171  which protrude outward in the radius direction formed at the positions corresponding to the protrusions  141  of the upper case  14 . 
     The upper section of the shaft unit and the lower section of the shaft unit are integrated by fixating the flange  12  and the cylinder  13  of the upper case  14  which form the upper section of the shaft unit to the lower case  17  which forms the lower section of the shaft unit with screws  18  at the positions corresponding to the protrusions  141  and  171 . 
     Further, at the edge of the opening on the lower side of the lower case  17 , an inside flange  172  which protrudes inward of the lower case  17  is formed. 
     The inner diameter of the inside flange  172  is smaller than the outer diameter of the flange  521  of the after-mentioned ring member  52 , and the under surface of the flange  521  of the ring member  52  abuts the upper surface of the inside flange  172  so that the lower case  17  supports the ring member  52  which forms the shaft tip unit  11  from below to prevent the ring member  52  from falling. Further, in the state where the under surface of the flange  521  abuts the upper surface of the inside flange  172 , the ring member  52  which forms the shaft tip unit  11  and the lower end section of the spherical body  51  which is the member that comes in contact with the ground are exposed from the opening at the bottom of the lower case  17 . 
     In the space formed by the upper case  14  and the lower case  17 , the shaft unit main body  50  whose shaft center is the axis that matches the rotation center of the toy top  1  is disposed. 
       FIG. 6A  is a perspective view of the shaft unit main body and  FIG. 6B  is a perspective view illustrating the inner structure where the first pillar member is removed from the shaft unit main body shown in  FIG. 6A . 
     As shown in  FIGS. 4, 6A and 6B , the shaft unit main body  50  includes the shaft tip unit  11 , the first pillar member  53  and the second pillar member  54 . 
     In the embodiment, the shaft tip unit  11  is formed of the member that comes in contact with the ground and the ring member  52 . 
     That is, the shaft tip unit  11  is provided at the lower end section of the shaft unit  10  and the shaft tip unit  11  includes the ring member  52  which rotates freely centering around the axis and the member that comes in contact with the ground which is disposed at the center of the ring member  52  and whose tip, at least, protrudes downward than the ring member  52 . 
     The member that comes in contact with the ground is the part which directly comes in contact with the field or the like when playing with the toy top  1  and in the embodiment, the member that comes in contact with the ground includes an arc unit  511  which protrudes downward than the ring member  52 . More specifically, the member that comes in contact with the ground of the embodiment is the spherical body  51  which is formed to have the largest diameter at the center section thereof. 
     The spherical body  51  is a metallic ball, for example. Here, the material used for the spherical body  51  is not limited to metal and for example, the spherical body  51  can be made of a hard resin or the like, for example. 
     Although the size of the spherical body  51  is not specifically limited, the larger the diameter of the spherical body  51 , the easier to stabilize the posture of the toy top  1  when it is about to fall. 
       FIG. 5B  is a perspective view of the ring member  52 . 
     The ring member  52  is a ring member which holds the spherical body  51  so as to rotate freely by supporting the lower section of the spherical body  51 , which is the section of the spherical body  51  on the lower side of the center section in the up-down direction. 
     That is, in the embodiment, the diameter at the center section of the spherical body  51  is the largest diameter and the ring member  52  supports the spherical body  51  by the lower section thereof, the lower section being on the lower side of the section having the largest diameter, so that the spherical body  51  does not fall downward from the ring member  52 . 
     Specifically, as shown in  FIGS. 4 and 5B , the ring member  52  is a cylindrical member whose upper end and lower end are opened, and the ring member  52  is provided with a flange  521  which protrudes outward at the edge of the upper side opening thereof. 
     As described above, when assembled, the under surface of the flange  521  abuts the upper surface of the inside flange  172  of the lower case  17  and the flange  521  is supported by the lower case  17  from below so as not to fall downward. 
     In such way, by having the ring member  52  which supports the spherical body  51  which is the member that comes in contact with the ground, the ring member  52  comes in contact with the field or the like when the shaft unit  10  tilts by a predetermined angle or greater. Since the part of the ring member  52  that comes in contact with the field or the like is apart from the axis (rotational center) of the shaft unit  10  to a certain extent, optimum brake can be applied to the toy top  1 . 
     Moreover, at the edge of the lower side opening of the ring member  52 , the inside flange  522  which protrudes inward is formed. 
     The inner diameter of the inside flange  522  is smaller than the diameter of the section of the spherical body  51  having the largest diameter and when assembled, the spherical body  51  abuts the inside flange  522  and the spherical body  51  is supported by the ring member  52  so as not to fall downward. 
     Further, at the lower edge section of the ring member  52 , protrusions  523  which protrude outward from the ring member  52  are formed. 
     The protrusions  523  come in contact with the field surface or the like when the axis of the shaft unit  10  tilts to a certain extent from the vertical direction. By having the protrusions  523 , each protrusion  523  comes in contact with the field surface or the like as a point when the axis of the shaft unit  10  tilts. Therefore, the contact area of a protrusion  523  and the field surface can be smaller comparing to the case where the lower end section of the ring member  52  comes in contact with the field surface or the like as a surface and the rotational energy loss can be controlled to be small. 
     In the embodiment, a plurality of protrusions  523  are formed at the lower end section of the ring member  52  along the circumference of the ring member  52  having approximately equal intervals therebetween (as shown in  FIG. 4 , there are four in the embodiment). 
     Although the number of the protrusions  523  and the disposition thereof are not specifically limited, the more the protrusions  523 , the easier the ring member  52  comes in contact with the field or the like as a point by a protrusion  523 . Further, it is preferred to dispose the protrusions  523  so as to have equal intervals therebetween as much as possible, since in such way, the toy top  1  becomes stable due to the weight being in balance and the protrusions are likely to come in contact with the field or the like even if they approach and come in contact with the field or the like from different directions. 
     Further, although the shape and size of the protrusions  523  are not specifically limited, the sides of the protrusions  523  which come in contact with the ground are formed in the R shape. By making the protrusions  523  have rounded corners in such way, the impact force of the collision when a protrusion  523  come in contact with the field or the like can be alleviated. 
     The first pillar member  53  and the second pillar member  54  are abutting members which abut the upper side of the shaft tip unit  11 . 
     The first pillar member  53  includes a tube unit  531  whose lower end is opened. 
     The outer diameter of the tube unit  531  is smaller than the inner diameter of the cylinder  151  of the above-mentioned pressing member  15 , and the upper end section of the tube unit  531  of the first pillar member  53  is fit in the cylinder  151 . 
     Although the height position of the upper end of the tube unit  531  in the fitted state is not specifically limited, the height position is set to be higher than the upper end of the cylinder  151  of the pressing member  15 . 
     At the upper end section of the tube unit  531 , hooks (the second hooks)  536  which protrude outside in the radius direction are formed at two positions that face each other in the front-rear direction having the axis of the shaft unit  10  therebetween. 
     The shape of the upper end section of the tube unit  531  corresponds to the shape of the hole  154  which is formed in the ceiling  152  of the pressing member  15 , and the upper end section of the tube unit  531  fits in the hole  154  of the pressing member  15  when the tube unit  531  is fit in the cylinder  151 . 
     On the outer peripheral of the tube unit  531  of the first pillar member  53  at the lower section thereof, engaging arms  532  which extend outward in an approximately horizontal manner are formed at two positions that face each other in the left-right direction having the axis of the shaft unit  10  therebetween. The first holes  533  are formed on the base end sides of the engaging arms  532  and the second holes  534  are formed on the free end sides of the engaging arms  532 . 
     The first holes  533  are formed in a rectangular shape which corresponds to the shape of the protrusions  544  of the legs  542  of the after-mentioned second pillar member  54 , and the protrusions  544  are inserted in the first holes  533  when assembled. Further, the second holes  534  are formed in a circular shape, and the screws  18  used for engaging the upper case  14  with the lower case  17  are inserted in the second holes  534 . 
     Here, with respect to each engaging arm  532 , the first hole  533  and the second hole  534  are connected as one to form a key-hole shaped hole unit in the embodiment. The shape of the holes is not limited to the example shown in the drawing. 
     Moreover, on the outer peripheral of the tube unit  531  of the first pillar member  53  at the lower section thereof, legs  535  which extend downward are formed on both sides of the engaging arms  532 . 
     With respect to the legs  535 , the lower end sections thereof (that is, the free ends of the legs  535 ) abut the upper end surface of the ring member  52  of the shaft tip unit  11  or they are disposed near the upper end surface of the ring member  52  as shown in  FIG. 6A . In such way, the ring member  52  of the shaft tip unit  11  is prevented from being raised upward. 
     Here, the shape of the legs  535  and the positions and ranges where they are to be disposed are not limited to the example described here. 
     The second pillar member  54  includes a pillar unit  541  whose upper end is opened and legs  542  which extend outward from the outer peripheral of the pillar unit  541  at the lower section thereof. 
     The inner diameter of the tube unit  531  of the first pillar member  53  is larger than the outer diameter of the pillar unit  541  of the second pillar member  54 , and the pillar unit  541  of the second pillar member  54  is to be fit in the tube unit  531  of the first pillar member  53 . 
     Here, although the pillar unit  541  of the second pillar member  54  is formed as a cylinder shape where inside thereof is hollow is exemplified in the embodiment, the pillar unit  541  is not limited to be hollow inside and it may be solid. 
     In order to make the toy top  1  lighter, it is preferred that the pillar unit  541  is formed in a cylinder shape where inside thereof is hollow as in the embodiment. 
     With respect to the pillar unit  541  of the embodiment, the lower end thereof is covered and this lower end abuts the spherical body  51  which is the member that comes in contact with the ground from above. Here, the shape of the part which abuts the spherical body  51  is not limited to the example shown in the drawing. 
     For example, the lower end of the pillar unit  541  may be formed in a convex shape or an arc shape whose shaft center protrudes toward the spherical body  51  or in contrast, the lower end of the pillar unit  541  may be formed in a concave shape whose shaft center concaves in the direction parting from the spherical body  51  or in an arc shape that fits along the surface of the spherical body  51 . 
     Further, the lower end of the pillar unit  541  may be opened and in such case, the opening end of the pillar unit  541  abuts the spherical body  51 . 
     Moreover, each leg  542  of the second pillar member  54  is formed of a horizontal unit  543  which extends in an approximately horizontal manner from the pillar unit  541  and a protrusion  544  which protrudes upward from the tip (free end) of the horizontal unit  543 . 
     As described above, the protrusions  544  are formed in a rectangular shape which corresponds to the shape of the first holes  533 , and the protrusions  544  are inserted in the first holes  533  when assembled. 
     2. Performance Changing Ring  30   
       FIG. 7B  is a cross-sectional perspective view of the performance changing ring according to the embodiment. 
     In the embodiment, a flywheel is used as the performance changing ring  30 . 
     The performance changing ring  30  is formed in a plate form. 
     On the bottom surface of the performance changing ring  30 , an annular step  31  which can house the flange  12  of the shaft unit  10  from the lower side is formed. 
     Further, on the upper surface of the performance changing ring  30 , protrusions  32  which protrude upward are formed at two positions that face each other in the left-right direction having the axis of the shaft unit  10  therebetween. At the lower sections of the protrusions  32 , recesses  33  which can house the protrusions  141  of the shaft unit  10  from below are formed. Further, on the upper surface of the performance changing ring  30 , tongues  34  which extend upward along the outer side of the respective protrusions  32  are formed. The tongues  34  protrude higher than the protrusions  32 . Alternatively, the performance changing ring  30  may be constituted by a member that includes a protrusion on the outer peripheral face for facilitating an attack on an opponent&#39;s toy top  1  or a member that includes a recess on the outer peripheral face for averting an attack from the opponent&#39;s toy top  1 . Such a member may be provided instead of or integrally with a flywheel. 
     3. Body  40   
       FIG. 7A  is a cross-sectional perspective view of the body according to the embodiment. 
     The body  40  is formed in a disk shape. As shown in  FIG. 2 , the body  40  includes a base  400  and a transparent cover  401  that is formed in an approximately same shape as the base  400  in the plan view and is placed on the base  400 . 
     On the outer peripheral of the body  40 , an uneven pattern  40   a  is formed. Further, at the center of the base  400 , a round hole  41  is formed. The transparent cover  401  covers portions other than the round hole  41 . In the bottom surface of the body  40 , a circular recess  42  is formed which can house the protrusions  32  of the performance changing ring  30  from below. 
     The circular recess  42  is defined by an inner peripheral wall  43   a , and two hooks (the first hooks)  44  which protrude inward in the radial direction are formed at the lower end section of the inner peripheral wall  43   a  on the inner peripheral surface thereof at two positions that face each other in the front-rear direction having the axis of the shaft unit  10  therebetween. 
     Further, on the lower end surface of the inner peripheral wall  43   a , grooves  45  which engage with the ridges  21  are formed, the grooves  45  being formed by concaves and bumps being formed continuously, at two positions that face each other in the left-right direction having the axis of the shaft unit  10  therebetween. 
     Further, the circular recess  42  of the body  40  is also defined by a roof wall  43   b , and arc slits  46  are formed in the roof wall  43   b , into which the tongues  34  of the performance changing ring  30  can be inserted from below. The arc slits  46  have such a length that allows the tongues  34  to move an adequate distance. 
     &lt;Assembling Method&gt; 
     Next, an example of the assembling method of the toy top  1  will be described. Here, it is assumed that the shaft unit  10  is already assembled. 
     First, the protrusions  141  of the shaft unit  10  are fitted in the recess  33  of the performance changing ring  30  from below so that the shaft unit  10  matches with the performance changing ring  30 . 
     Subsequently, the assembly is brought toward the body  40  from the lower side. In this step, the tongues  34  of the performance changing ring  30  of the assembly are set to predetermined ends of the arc slits  46  of the body  40  ( FIG. 8A ). In this state, the hooks  536  of the shaft unit  10  do not overlap the hooks  44  of the body  40  in the vertical direction. This state is referred to as a coupling releasable state. 
     Thereafter, the shaft unit  10  of the assembly is pushed toward the body  40 . Then, the performance changing ring  30  firstly abuts the bottom face of the body  40 . Further, the spring  16  in the shaft unit  10  shrinks and the hooks  536  of the shaft unit  10  are pushed up higher than the hooks  44  of the body  40 . Subsequently, the shaft unit  10  is made to rotate together with the performance changing ring  30  relative to the body  40  until the tongues  34  reach the other ends of the predetermined ends ( FIG. 8B ). This rotation is a relative rotation of the body  40  relative to the performance changing ring  30  and the shaft unit  10 .  FIG. 8B  illustrates a state in which the body  40  has been already made to rotate relative to the shaft unit  10  and the performance changing ring  30  from the state illustrated in  FIG. 8A . After this step, as shown in  FIG. 8B , the hooks  536  of the shaft unit  10  are aligned with the hooks  44  of the body  40  in the vertical direction. When the shaft unit  10  is released, the lower surface of the hooks  536  of the shaft unit  10  abuts the upper surface of the hooks  44  of the body  40  by the action of the biasing force of the spring  16 . 
     Such state where the lower surface of the hooks  536  of the shaft unit  10  abuts the upper surface of the hooks  44  of the body  40  is the coupled state. In such way, the shaft unit  10 , the performance changing ring  30  and the body  40  are coupled with one another and the toy top  1  is thus assembled. 
     &lt;How to Play&gt; 
     Next, an example of how to play with the toy top  1  and operation of the toy top  1  will be described. 
     In this example, a player spins a toy top  1  to battle with an opponent&#39;s toy top  1 . 
     In such cases, a launcher  60  as illustrated in  FIG. 9  is used to apply a rotary force to the toy top  1 . The launcher  60  includes a disk (not shown) therein. The launcher  60  is configured such that when a string (not shown) wound around the disk is pulled by means of a handle  61  while a spiral spring (not shown) biases the disk in a certain rotational direction, the disk is rotated, and a top holder  63  is made to rotate accordingly. 
     When the toy top  1  is attached to the top holder  63  and the top holder  63  is made to rotate, the rotation of the top holder  63  is transmitted to the toy top  1  through forks  64  that protrude downward, so that the toy top  1  spins. In such case, the forks  64  are inserted in the arc slits  46  of the body  40 . Then, when the handle  61  of the launcher  60  is completely pulled, the disk and the top holder  63  stop rotating while the toy top  1  continues rotating by the action of its inertial force. Therefore, the toy top  1  follows the tilted surfaces  64   a  of the forks  64  and detaches from the top holder  63 . In  FIG. 9 , the reference sign  62  denotes a rod that is retractable into the top holder  63 . When the toy top  1  is loaded in the top holder  63 , the rod  62  is pushed in the top holder  63  by the upper face of the toy top  1 . For example, the rod  62  is used for detecting attachment/detachment of the toy top  1 . 
     The toy top  1  thus launched is led to a predetermined field where it spins. When the toy top  1  collides with an opponent&#39;s toy top  1 , the impact or friction of the collision produces a force that acts in the body  40  in the direction opposite to the spinning direction of the shaft unit  10  and the performance changing ring  30 . The body  40  thereby relatively turns in the direction opposite to the spinning direction of the shaft unit  10  and the performance changing ring  30 . 
     Then, the ridges  21  engage with the grooves  45  of the body  40 . In such case, the biasing force of the coil spring  16  acts on the ridges  21  and thereby, the shaft unit  10  relatively rotates with respect to the body  40  and their engaging position changes gradually every time the impact force of collision is produced. When the shaft unit  10  reaches the coupling release position, the hooks  44  of the body  40  are released from the hooks  536  of the shaft unit  10  so that the body  40  separates from the shaft unit  10  by the action of the biasing force of the spring  16 . Accordingly, the toy top  1  is disassembled as the shaft unit  10 , the performance changing ring  30 , and the body  40  as illustrated in  FIG. 1B . 
     In the embodiment, since the arc unit  511  of the spherical body  51  which is the member that comes in contact with the ground, the spherical body  51  being supported so as to rotate freely, comes in contact with the field, the resistance that occurs when coming in contact with the ground is smaller comparing to the case where the member that comes in contact with the ground is formed in a rod shape or in a needle shape and the toy top  1  spins smoothly. Further, when the toy top  1  is thrown in to the field or when the toy top  1  collides with an opponent&#39;s toy top and bounces off, the ring member  52  comes in contact with the field and brakes are applied when the shaft unit  10  tilts by a predetermined angle or greater. Therefore, the toy top  1  can be prevented from flying out from the field and the toy top  1  which is about to fall can restore its posture by the ring member  52  acting as a support. 
     Especially, in the case where the field where the game is played is formed in the shape of a mortar being surrounded by a sloped wall, the toy top  1  will climb up the slope when the toy top  1  is thrown in to the field or when the toy top  1  collides with an opponent&#39;s toy top and is bounced off. At this time, if the toy top  1  is not provided with the ring member  52 , there is a possibility that the toy top  1  will climb up the slope and fly out from the field. With respect to this point, brakes are applied due to the ring member  52  coming in contact with the ground and the toy top  1  can be prevented from flying out from the field. 
     Moreover, although the spherical body  51  and the ring member  52  are restricted from moving in the up and down directions by being disposed between the lower case  17  and the abutting member, they are not fixated. Therefore, the spherical body  51  and the ring member  52  are not prevented from rotating centering around the axis and the friction resistance that occurs in the rotation direction when the spherical body  51  and the ring member  52  come in contact with the field can be controlled to be small. 
     Further, since the protrusions  523  are formed at the lower end section of the ring member  52 , brakes can be applied due to a protrusion  523  coming in contact with the field as a point when the shaft unit  10  tilts. Therefore, the friction resistance can be controlled to be smaller comparing to the case where the ring member  52  comes in contact with the field as a surface. 
     &lt;Advantages of the Embodiments&gt; 
     As described above, according to the embodiment, the spherical body  51  whose part that comes in contact with the ground is the arc unit  511  is adopted as the member that comes in contact with the ground. Therefore, resistance that occurs when the member comes in contact with the field or the like is smaller comparing to the case where the member that comes in contact with the ground is formed in a rod shape or a needle shape and the toy top  1  can spin smoothly for a long period of time. 
     Further, the spherical body  51  as the member that comes in contact with the ground is supported by the ring member  52 . Therefore, brakes are applied due to the ring member  52  coming in contact with the field when the shaft unit  10  tilts by a predetermined angle or greater and the toy top  1  can be prevented from flying out from the field. Moreover, due to the ring member  52  coming in contact with the field, the toy top  1  which is about to fall can restore its posture by the ring member  52  acting as a support. In such way, a toy top which spins stably for a long period of time can be realized. 
     Furthermore, the ring member  52  itself can also rotate freely independently from the spherical body  51  in the embodiment. Therefore, due to the ring member  52  rotating around the axis even if the ring member  52  comes in contact with the field, the friction resistance that occurs in the rotation direction of the toy top  1  can be controlled to be small and the rotational energy loss in the toy top  1  can be kept to the minimum loss. 
     Further, in the embodiment, the member that comes in contact with the ground is the spherical body  51  and the ring member  52  supports the spherical body so as to rotate freely by holding the section of the spherical body  51  lower than the center section in the up-down direction. Therefore, the spherical body  51  can be prevented from falling downward, the rotation of the spherical body  51  is not blocked and the friction resistance that occurs when the spherical body  51 , which rotates freely, comes in contact with the field can be kept at minimum. Thus, the toy top  1  which continues its smooth rotation for a long period of time can be realized. 
     Furthermore, in the embodiment, the shaft tip unit  11  is disposed between the lower case  17  which supports the shaft tip unit  11  from below in a movable manner and the abutting member which abuts the upper side of the shaft tip unit  11 . 
     Therefore, even without having an independent shaft receiving member, the shaft tip unit  11  is restricted from moving in up and down directions while maintaining the rotation around the axis and the rotational energy is not easily lost when the spherical body  51  or the ring member  52  which form the shaft tip unit comes in contact with the field. Thus, the toy top which can continue to spin more smoothly for a long period of time can be realized. 
     Moreover, since the protrusions  523  are formed at the lower end section of the ring member  52  in the embodiment, brakes can be applied by a protrusion  523  coming in contact with the field as a point when the shaft unit  10  tilts. In such way, the friction resistance is smaller comparing to the case where the main body of the ring member  52  comes in contact with the field as a surface and the rotational energy loss can be controlled to be even smaller. 
     Further, due to a protrusion  523  coming in contact with the field as a point, the rotation is changed and the toy top  1  flies in an unexpected direction. Thus, the game proceeds unexpectedly and the game becomes more interesting. 
     Moreover, in the embodiment, a plurality of protrusions  523  are formed along the circumference direction of the ring member  52  having approximately equal intervals therebetween. Therefore, the toy top  1  can restore its posture stably even if the shaft unit  10  tilts in different directions. 
     Furthermore, by having a plurality of protrusions  523 , it is expected that the toy top  1  bounces off for several times in complicated ways when the protrusions  523  come in contact with the field. Thus, the game proceeds more unexpectedly and the game can be played without the players losing interest. 
     Moreover, in the embodiment, the sides of the protrusions  523  that come in contact with the ground are formed in the R shape. Therefore, since the protrusions  523  come in contact with the field more softly comparing to when the protrusions  523  come in contact with the field by their corners, the impact force of the collision can be alleviated and the rotational energy loss can be even smaller. 
     &lt;Modifications of the Present Invention&gt; 
     Although an embodiment of the present invention is described above, the present invention is not limited to the embodiment and it is needless to mention that various modifications can be made within the scope of the invention. 
     For example, in the above described embodiment, an example where the spherical body  51  is provided as the member that comes in contact with the ground is shown. However, the member that comes in contact with the ground is not limited to a spherical body and any member can be adopted as the member that comes in contact with the ground as long as at least a part thereof protrudes downward than the ring member  52 . 
     Further, the member that comes in contact with the ground does not need to be formed in a spherical shape as long as the part that protrudes downward than the ring member  52  is the arc unit  511 . For example, the member that comes in contact with the ground where the R is provided at the tip of a rod shaped member as the arc unit can be adopted. 
     In such way, in the case where the member that comes in contact with the ground includes the arc unit which protrudes downward than the ring member  52 , the member comes in contact with the field smoothly similarly to the case where the member that comes in contact with the ground is the spherical body  51 . Thus, the toy top can spin stably and it does not easily fall. 
     Here, it is sufficient that the shaft tip unit  11  includes the ring member which rotates freely centering around the axis of the shaft unit  10  and the member that comes in contact with the ground which is disposed at the center of the ring member and which protrudes downward than the ring member, and the shape of the member that comes in contact with the ground is not specifically limited. For example, the tip of the member may be formed in a cone shape or the like. 
     In any of the above cases, by disposing the ring member  52  so as to surround the member that comes in contact with the ground, brakes are applied by the ring member  52  coming in contact with the field if the shaft unit  10  tilts by a predetermined angle or greater and the toy top  1  can be prevented from flying out from the field. Further, by the ring member  52  coming in contact with the field, the toy top  1  which is about to fall can restore its posture by the ring member  52  acting as a support. 
     It is not required to have the protrusions  523  formed at the lower end section of the ring member  52  and the configuration may be made without them. 
     Although various exemplary embodiments have been shown and described, the invention is not limited to the embodiments shown. Therefore, the scope of the invention is intended to be limited solely by the scope of the claims that follow and its equivalents. 
     The present U.S. patent application claims priority under the Paris Convention of Japanese Patent Application No. 2016-204640 filed on Oct. 18, 2016 the entirety of which is incorporated herein by reference.