Patent Publication Number: US-2022227174-A1

Title: Tire

Description:
TECHNICAL FIELD 
     The disclosure relates to a tire. 
     BACKGROUND 
     Tires including coil springs are conventionally known. For example, Patent Literature (PTL) 1 discloses a tire in which a respective plurality of coil springs are interlaced with other coil springs and secured to annular rims to form a toroidal shape as a whole. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: WO 2010/138150 
       
    
     SUMMARY 
     Technical Problem 
     However, in a tire as disclosed in PTL 1, in a case in which an elastic deformable portion such as a coil spring comes off from an annular rim, the tire may not be able to maintain its shape and may cease to function as a tire. 
     It would be helpful to provide a tire in which an elastic deformable portion is reliably joined to a rim member. 
     Solution to Problem 
     A tire according to the disclosure is a tire including: a plurality of rim members disposed at different positions on the same axis; a plurality of body springs that connect between the respective plurality of rim members; and an interlink member that interlinks the adjacent body springs, wherein each of the plurality of body springs includes: an elastic deformable portion; and latch portions provided at both ends of the elastic deformable portion, the latch portions having a different shape from the elastic deformable portion, and the latch portions are latched on the rim members. 
     Advantageous Effect 
     According to the disclosure, it is possible to provide a tire and a body spring in which an elastic deformable portion is reliably joined to a rim member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  is an external perspective view of a tire according to an embodiment of the disclosure; 
         FIG. 2  is an external perspective view of a wheel portion of  FIG. 1 ; 
         FIG. 3  is a schematic diagram illustrating an example of a body spring that configures a grounding deformable portion of  FIG. 1 ; 
         FIG. 4  is a schematic diagram illustrating an example of an aspect of engaging the body springs with a rim member; 
         FIG. 5  is a cross sectional view along the line A-A of  FIG. 4 ; 
         FIG. 6  is a cross sectional view along the line B-B of  FIG. 4 ; 
         FIG. 7  is a schematic diagram of an example of an interlink spring that configures the grounding deformable portion of  FIG. 1 ; 
         FIG. 8A  is a schematic diagram illustrating an example of a method for joining the interlink spring to the body springs; 
         FIG. 8B  is a schematic diagram illustrating the example of the method for joining the interlink spring to the body springs; 
         FIG. 8C  is a schematic diagram illustrating an example of a method for joining the interlink springs to the body springs; 
         FIG. 9  is a schematic diagram illustrating a variation of a limitation portion; 
         FIG. 10  is a schematic diagram illustrating a variation of a latch portion; 
         FIG. 11  is a schematic diagram illustrating a variation of the body springs and the interlink springs; 
         FIG. 12  is a schematic diagram illustrating a variation of an interlink member; and 
         FIG. 13  is a schematic diagram illustrating an example of joining the body springs using the interlink members of  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION 
     An embodiment of the disclosure will be exemplarily described below with reference to the drawings. 
       FIG. 1  is an external perspective view of a tire according to an embodiment of the disclosure. As illustrated in  FIG. 1 , a tire  1  according to the present embodiment includes a wheel portion  10  having a rim portion, and a grounding deformable portion  20  that is deformable while being grounded. 
       FIG. 2  is an external perspective view of the wheel portion  10  of  FIG. 1 . The wheel portion  10  is provided with a plurality of rim members. In the present embodiment, as illustrated in  FIGS. 1 and 2 , the wheel portion  10  is provided with, as the rim members, a first rim member  101  and a second rim member  102 . The number of the plurality of rim members provided in the wheel portion  10  does not necessarily have to be two as in the present embodiment, but can be two or more. In the present embodiment, as illustrated in  FIG. 2 , the wheel portion  10  is further provided with a plurality of connection members  103 . 
     The first rim member  101  and the second rim member  102  are made of metal or resin. The first rim member  101  and the second rim member  102  are disposed at different positions on the same axis. The first rim member  101  and the second rim member  102  are each formed in an annular shape. In the present embodiment, the first rim member  101  and the second rim member  102  are configured to be the same size and shape. However, as long as the tire  1  can perform functions as a tire, the first rim member  101  and the second rim member  102  may be configured in different sizes or shapes. The outer diameter of the first rim member  101  and the second rim member  102  may be determined according to the size of the tire  1  required. 
     The connection members  103  are members that connect between the first rim member  101  and the second rim member  102 . The connection members  103  are made of metal or resin. In the present embodiment, as illustrated in  FIG. 2 , the wheel portion  10  is provided with six connection members  103 , but the number of the connection members  103  provided in the wheel portion  10  is not limited thereto. The plurality of connection members  103  are attached to one side of the annular first rim member  101  and one side of the annular second rim member  102 . In this specification, in the wheel portion  10 , the side on which the connection members  103  are attached to the first rim member  101  and the second rim member  102  is referred to as an inner side in a tire width direction, and the side on which the connection members  103  are not attached is referred to as an outer side in the tire width direction. 
     In the present embodiment, the first rim member  101  and the second rim member  102  have, in inner surfaces in the tire width direction, engagement receiving portions  105  (see  FIG. 5 ) in which body springs  201  of the grounding deformable portion  20  are engaged. Details of the engagement receiving portions and an aspect of engagement will be described later. In this specification, “engagement” refers to being fitted together, and “latching” refers broadly to being fastened together, including being fitted together. 
     In the present embodiment, as illustrated in  FIG. 2 , a support member  104  is attached to each of the first rim member  101  and the second rim member  102 . The support member  104  is a member that maintains a state of engaging the grounding deformable portion  20  in the engagement receiving portions  105  (see  FIG. 5 ). The support members  104  can be secured to the inner side of the first rim member  101  and the second rim member  102  in the tire width direction using, for example, bolts. 
     In the present embodiment, the grounding deformable portion  20  is configured with members including elastic deformable portions. In the present embodiment, as illustrated in  FIG. 1 , the grounding deformable portion  20  includes two kinds of members: body springs  201  and interlink springs  211 . The body springs  201  and the interlink springs  211  are made of metal. 
       FIG. 3  is a schematic diagram illustrating an example of the body spring  201  that configures the grounding deformable portion  20  of  FIG. 1 . The body springs  201  connect between the plurality of rim members. In the present embodiment, the body springs  201  connect between the first rim member  101  and the second rim member  102 . In a case in which the tire  1  has three or more rim members, the body springs  201  may connect at least one of spaces between the adjacent rim members, though it is preferable that the body springs  201  connect the respective spaces between the adjacent rim members in a manner similar to the manner of connecting between the first rim member  101  and the second rim member  102  described herein. As illustrated in  FIG. 3 , the body spring  201  has an elastic deformable portion  202  and latch portions  203 . 
     In the present embodiment, the elastic deformable portion  202  is constituted of a coil spring. Here, the coil spring refers to a spring that deforms elastically in response to a load and is coiled (spirally wound) around a predetermined axis. The elastic deformable portion  202  that is made of a suitable material and has appropriate elasticity can be used according to the size and weight of the tire  1 , required properties of the grounding deformable portion  20 , and the like. 
     The latch portions  203  are provided at both ends of the elastic deformable portion  202 . The latch portions  203  latch the body spring  201  to the wheel portion  10 . The latch portions  203  have a different shape from the elastic deformable portion  202 . That is, in the present embodiment, the latch portions  203  have a shape different from a coil shape. 
     In the present embodiment, the latch portions  203  are constituted of members integral with the elastic deformable portion  202 . That is, in the present embodiment, as illustrated in  FIG. 3 , for example, a material composing the elastic deformable portion  202  extends from both the ends of the elastic deformable portion  202  to configure the latch portions  203 . 
     In the present embodiment, as illustrated in  FIG. 3 , for example, the latch portions  203  include straight portions  203   a  that are formed in a linear shape and are joined to both the ends of the elastic deformable portion  202 . Also in the present embodiment, as illustrated in  FIG. 3 , for example, the latch portions  203  include, at tip ends of the straight portions  203   a , bent portions  203   b  that are bent with respect to the straight portions  203   a . In the present embodiment, the bent portions  203   b  are bent orthogonally with respect to the straight portions  203   a  in a side view of the body spring  201  (in a plane containing an axis of the body spring  201 ). 
     Referring to  FIGS. 4 to 6 , an aspect of engaging the body springs  201  in the wheel portion  10  according to the present embodiment will be described in detail. One of the latch portions  203  provided at both the ends of the body spring  201  is engaged in the first rim member  101 , and the other latch portion  203  is engaged in the second rim member  102 . An example of a case in which one of the latch portions  203  is engaged in the first rim member  101  will be described here, but the other latch portion  203  can be engaged in the second rim member  102  in the same manner. 
       FIG. 4  is a schematic diagram illustrating an example of an aspect of engaging the body springs  201  in the first rim member  101 , in which an engagement state of the body springs  201  is viewed from the inner side of the first rim member  101  in the tire width direction.  FIG. 4  illustrates only part of the first rim member  101  in which the body springs  201  are engaged, but the body springs  201  are practically engaged, as illustrated in  FIG. 4 , over the entire circumference of the first rim member  101  in the first rim member  101 . 
     In the present embodiment, as illustrated in  FIG. 4 , the body springs  201  can be engaged in the first rim member  101  by engaging the latch portions  203  in the engagement receiving portions  105  provided in a surface of the first rim member  101  on the inner side in the tire width direction. In the present embodiment, in particular, the engagement receiving portion  105  is configured as a hole into which the bent portion  203   b  of the latch portion  203  is insertable. Inserting the bent portions  203   b  into the holes of the engagement receiving portions  105  allows the body springs  201  to be engaged in the first rim member  101 . In a state of engaging the latch portions  203  in the engagement receiving portions  105 , the support member  104  is attached to the inner side of the first rim member  101  in the tire width direction in order to firmly secure the engagement state of the latch portions  203 . 
       FIG. 5  is a cross sectional view taken on the line A-A of  FIG. 4 , and specifically, a cross sectional view of the first rim member  101  at a point including the engagement receiving portion. As illustrated in  FIG. 5 , the first rim member  101  has the engagement receiving portion  105 . In the present embodiment, the engagement receiving portion  105  is configured as a hole into which the bent portion  203   b  is insertable. In the present embodiment, the engagement receiving portion  105  is configured as a bottomed hole. The length of the hole (depth of the hole) of the engagement receiving portion  105  in an extending direction is preferably longer than the length of the bent portion  203   b . As a result, the entire bent portion  203   b  can be inserted into the engagement receiving portion  105 , and the engagement state becomes more stable. However, the engagement receiving portion  105  may be configured as a bottomless hole (through hole). 
     The shape of cross section of the hole of the engagement receiving portion  105  is not limited as long as the bent portion  203   b  is insertable thereinto, and may be, for example, an ellipse, an oval, a rectangle, a polygon, or the like. In order to latch (secure) the elastic deformable portion  202  more reliably, it is preferable that the shape and size of cross section of the hole are approximately the same as the shape and size of cross section of the bent portion  203   b.    
     The body spring  201  is arranged such that, in a state of inserting the bent portion  203   b  into the engagement receiving portion  105 , the elastic deformable portion  202  is positioned, except for at least part, at a radially outer side (upper side in  FIGS. 5 and 6 ) of the tire of the annular first rim member  101 . In this state, the support member  104  is attached to the inner side (left side in  FIGS. 5 and 6 ) of the first rim member  101  in the tire width direction. The support member  104  is attached, as illustrated in  FIG. 5 , for example, to such a position as to retain the bent portion  203   b  inserted into the hole of the engagement receiving portion  105 , i.e., such a position as to prevent the bent portion  203   b  from slipping out of the hole of the engagement receiving portion  105 . The support member  104  is preferably attached in such a position as to block the hole of the engagement receiving portion  105  in a state of not inserting the body spring  201 . Also, as illustrated in  FIG. 5 , for example, the support member  104  is secured to the first rim member  101  so as to retain the straight portion  203   a  of the latch portion  203  on the inner surface of the first rim member  101  in the tire width direction. In this manner, the engagement state of the latch portion  203  is stably secured by the support member  104 . 
     The support member  104  is attached to the first rim member  101  using, for example, bolts  106 .  FIG. 6  is a cross sectional view of  FIG. 4  taken on the line B-B, and specifically, a cross sectional view of the first rim member  101  at a point including the bolt  106  for securing the support member  104 . As illustrated in  FIG. 6 , the support member  104  is secured to the first rim member  101  by the bolt  106 . As illustrated in  FIG. 4 , the support member  104  may be secured to the first rim member  101  at a position between (in the middle of) the two body springs  201  that are engaged in the first rim member  101 . That is, in the first rim member  101 , one bolt hole  107  for securing the bolt  106  is formed between the two adjacent engagement receiving portions  105  in a circumferential direction of the annular first rim member  101 . Thereby, it is possible to secure the support member  104  to the first rim member  101  without interfering with engagement positions of the body springs  201 . 
     The support member  104  may be constituted of a single annular member or as a plurality of divided members that form an annular shape in their entirety. In such a case, the support members  104  may be disposed so as to contact each other at their ends in the circumferential direction, or may be arranged with leaving appropriate clearances. In a case in which the support member  104  is constituted of the plurality of divided members, each member has, for example, the shape of a sector. 
     In the present embodiment, over the entire circumference of the first rim member  101 , one of the latch portions  203  (more specifically, the bent portions  203   b ) of each of the body springs  201  is engaged in the engagement receiving portion  105  of the first rim member  101 , and the support member  104  is secured to the first rim member  101 , in the above-described aspect. In this manner, the latch portions  203  are latched on the first rim member  101 . In a similar manner, over the entire circumference of the second rim member  102 , the other latch portion  203  (more specifically, the bent portion  203   b ) of each of the body springs  201  is engaged in an engagement receiving portion of the second rim member  102 , and the support member  104  is secured to the second rim member  102 . In this manner, the latch portions  203  are latched on the second rim member  102 . In the present embodiment, one and the other latch portions  203  of one body spring  201  may be engaged, in the first rim member  101  and the second rim member  102 , in the engagement receiving portions that are positioned on a straight line in an axial direction of the first rim member  101  and the second rim member  102 . In other words, in the present embodiment, two latch portions  203  of one body spring  201  may be secured to the first rim member  101  and the second rim member  102  at the same position with respect to the circumferential direction. However, the two latch portions  203  of the one body spring  201  may not necessarily be secured at the same position in the circumferential direction, with respect to the first rim member  101  and the second rim member  102 . 
     The number and intervals of the body springs  201  to be engaged in the first rim member  101  and the second rim member  102  may be determined as appropriate according to the size and weight of the tire  1 , required properties of the grounding deformable portion  20 , and the like. The number and intervals of the bolts  106  used to attach the support members  104  to the first rim member  101  and the second rim member  102  may also be determined as appropriate. For example, the bolt  106  does not necessarily have to be attached to every space between two of the engagement receiving portions  105  adjacent in the circumferential direction as in the present embodiment. 
     In the tire  1  according to the present embodiment, the plurality of body springs  201 , which are engaged in the wheel portion  10  in this manner, are interlinked with the interlink springs  211  to form the grounding deformable portion  20 . In other words, in the present embodiment, the interlink spring  211  functions as an interlink member to interlink the adjacent body springs  201 .  FIG. 7  is a schematic diagram illustrating an example of the interlink spring  211  composing the grounding deformable portion  20  of  FIG. 1 . In the present embodiment, as illustrated in  FIG. 7 , the interlink spring  211  has an elastic deformable portion  212  and a limitation portion  213 . Specifically, the interlink spring  211  is disposed between the two body springs  201  adjacent in the circumferential direction, which are engaged in the wheel portion  10 , and is interlaced with the two body springs  201  so as to be interlinked with the body springs  201 . 
     In the present embodiment, the elastic deformable portion  212  is constituted of a coil spring. The elastic deformable portion  212  that is made of a suitable material and has appropriate elasticity can be used according to the size and weight of the tire  1 , required properties of the grounding deformable portion  20 , and the like. It is preferable that the diameter of the coil spring constituting the elastic deformable portion  212  is close to the diameter of the coil spring constituting the elastic deformable portion  202  of the body spring  201 . Here, the diameter of the coil spring is the diameter of a circumscribed circle in the case of viewing the coil spring from an axial direction, and the same applies hereinafter. The closer the diameter of the coil spring constituting the elastic deformable portion  212  is to the diameter of the coil spring constituting the elastic deformable portion  202  of the body spring  201 , the more evenly force is applied to the grounding deformable portion  20  that is formed by interlinking the coil springs constituting the elastic deformable portions  202  with the coil springs constituting the elastic deformable portions  212  as described below. For example, both the diameter of the coil spring constituting the elastic deformable portion  202  and the diameter of the coil spring constituting the elastic deformable portion  212  can be 15 mm to 25 mm, e.g. 20 mm or the like. 
     In the present embodiment, the limitation portion  213  is provided at one end of the elastic deformable portion  212 . No other mechanism is provided at the other end of the elastic deformable portion  212  where the limitation portion  213  is not provided, and thus the elastic deformable portion  212  has an open shape at the other end. The limitation portion  213  limits displacement of the interlink spring  211 , which is to be interlinked with the body springs  201 , with respect to the body springs  201 . The limitation portion  213  limits displacement of the interlink spring  211  in at least one direction relative to the body springs  201 . In this way, by limiting displacement of the interlink spring  211  relative to the body springs  201  by the limitation portion  213 , in interlinking the interlink spring  211  with the body springs  201 , as described with reference to  FIGS. 8A, 8B, and 8C  below, the interlinked position of the interlink spring  211  is determined and secured. That is, an interlinked state of the interlink spring  211  with respect to the body springs  201  is positioned and secured. The limitation portion  213  has a different shape from the elastic deformable portion  212 . That is, in the present embodiment, the limitation portion  213  has a different shape from a coil shape. 
     In the present embodiment, the limitation portion  213  is constituted of a member integral with the elastic deformable portion  212 . That is, in the present embodiment, as illustrated in  FIG. 7 , for example, a material of the elastic deformable portion  212  extends from one end of the elastic deformable portion  212  to form the limitation portion  213 . In an example illustrated in  FIG. 7 , the limitation portion  213  has a ring-shaped portion formed with a wire, which forms the elastic deformable portion  212 , being bent into a ring shape. The ring-shaped portion is formed so as to have a central axis in a direction intersecting the direction of an axis A of the elastic deformable portion  212 . The ring-shaped portion of the limitation portion  213  may be of any size capable of limiting displacement of the interlink spring  211 . For example, the ring-shaped portion of the limitation portion  213  may be configured to have a diameter of 0.5 to 1.0 times the diameter of the elastic deformable portion  212 . 
     Here, the function of the limitation portion  213  will be described together with a method for interlinking the interlink spring  211  with the body springs  201 .  FIGS. 8A and 8B  are schematic diagrams for explaining an example of the method for interlinking the interlink spring  211  with the body springs  201 . 
     As illustrated in  FIG. 8A , the interlink spring  211  is interlinked with the two adjacent body springs  201  by hooking the elastic deformable portion  212  on the elastic deformable portions  202  of the body springs  201 , which are engaged in the wheel portion  10 , in such a manner as to be interlaced with the two adjacent body springs  201 . Specifically, the interlink spring  211  is interlinked with the body springs  201  so as to restrict the relative displacement between the two body springs  201  adjacent in the circumferential direction. At this time, the interlink spring  211  is gradually interlaced with the two adjacent body springs  201  by being inserted into the body springs  201  in such a manner as to move forward while rotating, from the side of the other end on which the limitation portion  213  is not provided. 
     As the entire elastic deformable portion  212  of the interlink spring  211  is interlaced with the body springs  201 , as illustrated in  FIG. 8B , the limitation portion  213  eventually comes into contact with the body spring  201 . The limitation portion  213 , due to its shape, cannot be interlaced with the body springs  201 . Therefore, the interlink spring  211  does not move in an insertion direction beyond the position at which the limitation portion  213  contacts the body spring  201 . In particular, the interlink spring  211  does not move forward (move in the insertion direction) after the ring-shaped portion of the limitation portion  213  contacts the body spring  201 , even if the interlink spring  211  is attempted to be moved forward while being rotated. Thus, the limitation portion  213  limits displacement of the interlink spring  211  in at least one direction relative to the body springs  201 . In this manner, the limitation portion  213  positions and secures an interlinked state of the interlink spring  211  with respect to the body springs  201 . In addition, the interlink spring  211  interlinked with the body springs  201  is prevented from coming off from the body springs  201 . 
     At least one of the two ends of the interlink spring  211  is not secured to the first rim member  101  and the second rim member  102 . In the present embodiment, neither of the ends of the interlink spring  211  is secured to the first rim member  101  and the second rim member  102 . In other words, in the present embodiment, the interlink spring  211  is not secured at either end. However, only one of the ends of the interlink spring  211  may be secured to the first rim member  101  or the second rim member  102 . In this case, the other end of the interlink spring  211 , which is opposite to the one end of the interlink spring  211  on which the limitation portion  213  is provided, is secured to the first rim member  101  or the second rim member  102 . 
     In the present embodiment, all the body springs  201 , which are engaged in the wheel portion  10 , are interlinked with the interlink springs  211  each disposed between the two adjacent body springs  201 . In the present embodiment, the tire  1  is configured in this manner. In other words, in the present embodiment, every body spring  201  of the grounding deformable portion  20  of the tire  1  is interlinked with the two interlink springs  211 , and every interlink spring  211  of the grounding deformable portion  20  of the tire  1  is interlinked with the two body springs  201 . Accordingly, the interlink springs  211  are each interlinked between the two adjacent body springs  201 , so even in the case of applying a load to the tire  1 , the distance between the body springs  201  does not widen too much, and the tire  1  can easily maintain its function as a tire. 
     At this time, the limitation portions  213  can limit displacement of the interlink springs  211  in at least one direction relative to the body springs  201  in the tire  1 , so that the interlink springs  211  interlinked with the body springs  201  are prevented from coming off from the body springs  201 . Therefore, the interlink springs  211  are mainly located in a grounding area of the tire  1 , and are not located in the vicinity of secured positions between the first rim member  101  and the body springs  201  and between the second rim member  102  and the body springs  201 . As a result, the elastic deformable portions  202  of the body springs  201  and the elastic deformable portions  212  of the interlink springs  211  are located in the grounding area of the tire  1 , while only the elastic deformable portions  202  of the body springs  201  are located in the vicinity of the secured positions between the first rim member  101  and the body springs  201  and between the second rim member  102  and the body springs  201 . Therefore, according to the tire  1  of the present embodiment, the elastic deformable portions  202  of the body springs  201  and the elastic deformable portions  212  of the interlink springs  211  serve to prevent a reduction in load durability performance of the tire  1 , while a congested state of the elastic deformable portions  202  at the secured positions to the first rim member  101  and the second rim member  102  is improved. 
     The interlink spring  211  that joins the two body springs  201  can be inserted from the side of the first rim member  101  or from the side of the second rim member  102  in the axial direction of the wheel portion  10  (i.e. the direction of a rotational axis of the tire  1 ). It is preferable that half of the plurality of interlink springs  211  in the tire  1  are inserted from the side of the first rim member  101 , and the other half thereof are inserted from the side of the second rim member  102 . This means that the limitation portions  213  of the interlink springs  211  are evenly arranged on both sides in the axial direction of the tire  1 , thus easily striking a balance of the tire  1  and preventing the limitation portions  213  from being congested in only one direction in the axial direction of the tire  1 . In particular, the plurality of interlink springs  211  are more preferably inserted such that, as illustrated as an example in  FIG. 8C , the interlink springs  211  that are adjacent to each other in the circumferential direction of the grounding deformable portion  20  are inserted from different directions. This further facilitates striking a balance of the tire  1 . 
     The tire  1  may also be provided with a connection member that connects the ring-shaped portions of the limitation portions  213  of the plurality of interlink springs  211 . The connection member is constituted of a wire, for example. For example, suppose that half of the plurality of interlink springs  211  are inserted from the side of the first rim member  101  and the other half thereof are inserted from the side of the second rim member  102 . In this case, the limitation portions  213  of the interlink springs  211  inserted from the side of the first rim member  101  are located on the side of the first rim member  101 , and the limitation portions  213  of the interlink springs  211  inserted from the side of the second rim member  102  are located on the side of the second rim member  102 . In this case, the tire  1  may have two wires, that is, a wire for connecting the ring-shaped portions of the plurality of limitation portions  213  located on the side of the first rim member  101  and a wire for connecting the ring-shaped portions of the plurality of limitation portions  213  located on the side of the second rim member  102 . The wire for connecting the ring-shaped portions of the plurality of limitation portions  213  located on the side of the first rim member  101  is provided, for example, along the circumferential direction of the wheel portion  10  so as to pass through central portions (openings formed by the ring-shaped portions) of all the ring-shaped portions of the plurality of limitation portions  213  located on the side of the first rim member  101 . Similarly, the wire for connecting the ring-shaped portions of the plurality of limitation portions  213  located on the side of the second rim member  102  is provided, for example, along the circumferential direction of the wheel portion  10  so as to pass through central portions of all the ring-shaped portions of the plurality of limitation portions  213  located on the side of the second rim member  102 . Such a wire is formed in a circular shape, for example, and therefore can connect the ring-shaped portions of the limitation portions  213  by passing through the central portions of the ring-shaped portions of the limitation portions  213 . Thus, the provision of the wires, which pass through the ring-shaped portions of the plurality of limitation portions  213 , limits displacement of the relative positions of the limitation portions  213 . As a result, the interlink springs  211  that are interlinked with the body springs  201  are further prevented from coming off from the body springs  201 . 
     However, the connection member for connecting the ring-shaped portions of the plurality of limitation portions  213  of the plurality of interlink springs  211  need not necessarily be configured to pass through the ring-shaped portions of the plurality of limitation portions  213  as described above, and the limitation portions  213  may be connected to each other by any form. In this case, for example, the connection member may be secured to each of the ring-shaped portions of the plurality of limitation portions  213  to be connected, thereby connecting the ring-shaped portions of the plurality of limitation portions  213 . By providing at least the wire for connecting the limitation portions  213  of the plurality of interlink springs  211 , displacement of the relative positional relationship between the interlink springs  211  connected by the wire is limited. 
     In the above embodiment, it is described that the limitation portion  213  is formed in a ring shape having a central axis in a direction intersecting the direction of the axis A of the elastic deformable portion  212 , but the shape of the limitation portion  213  is not limited thereto. The limitation portion  213  may have any configuration capable of limiting displacement of the interlink spring  211  in at least one direction relative to the body springs  201 . 
     In the above embodiment, it is described that the limitation portion  213  is constituted of a member integral with the elastic deformable portion  212 , but the limitation portion  213  does not necessarily have to be constituted of a member integral with the elastic deformable portion  212 . For example, as schematically illustrated in  FIG. 9 , a limitation portion  213  that is constituted of a member different from and independent of the interlink spring  211  may limit displacement of the interlink spring  211  relative to the body spring  201 . In the example illustrated in  FIG. 9 , the limitation portion  213  is configured as a member different from and independent of the interlink spring  211 , for limiting displacement of a contact point between the body spring  201  and the interlink spring  211  that are interlaced with each other. In this case, it is easy to freely select a point at which displacement of the interlink spring  211  is limited. 
     The length of the interlink spring  211  may be determined in appropriate according to the size and weight of the tire  1 , the required properties of the grounding deformable portion  20 , and the like. The interlink spring  211  is preferably configured to have the elastic deformable portion  212  that is shorter than the length of the elastic deformable portion  202  of the body spring  201 . The interlink spring  211  preferably has a length such that the elastic deformable portion  212  extends over the entirety in the tire width direction. In other words, the interlink spring  211  preferably has the elastic deformable portion  212  that extends over at least a maximum width of the tire  1  in the width direction of the tire  1 . In a case in which the interlink springs  211  extend over the maximum width of the tire, the positions of the ends of the interlink springs  211  in the width direction are indicated by the double-dotted line L in  FIG. 1 . In  FIG. 1 , however, the double-dotted line L indicates only the position of one of both ends of every interlink spring  211 . The position of the other end of every interlink spring  211  is symmetrical about a plane that is orthogonal to the rotational axis of the tire  1  and centered in the width direction of the tire  1 . By extending the elastic deformable portions  212  of the interlink springs  211  over the entirety in the width direction of the tire  1 , the elastic deformable portions  202  of the body springs  201  are interlinked with the elastic deformable portions  212  of the interlink springs  211  in at least the grounding area, thereby improving durability. 
     The elastic deformable portions  212  of the interlink springs  211  preferably extend over an entire crown portion of the tire  1 . The crown portion is a portion that is, in the grounding deformable portion  20  of the tire  1 , inflated outwardly in a radial direction of the tire  1  from side portions formed on approximately the same planes as the planes of the first rim member  101  and the second rim member  102 . The elastic deformable portions  212  of the interlink springs  211  further preferably extend to buttress portions of the tire  1 . The buttress portions are portions between each of the side portions and the crown portion in the grounding deformable portion  20 . In the grounding deformable portion  20 , a portion interlinked with the interlink springs  211  is hard to deform due to restraining force of the interlink springs  211 , and portions not interlinked with the interlink springs  211  are easy to deform because the restraining force of the interlink springs  211  does not work. By arranging the elastic deformable portions  212  in the crown portion and the buttress portions, as described above, the deformation of the crown portion and the buttress portions can be suppressed. On the other hand, by preventing the restraining force of the interlink springs  211  from working on the side portions, vibration at the time of grounding of the tire  1  can be absorbed. 
     Thus, according to the tire  1  of the present embodiment, each of the plurality of body springs  201 , which configure the grounding deformable portion  20 , has the elastic deformable portion  202  and the latch portions  203  that are provided at both ends of the elastic deformable portion  202  and have a shape different from the elastic deformable portion  202 . The latch portions  203  are latched on the first rim member  101  and the second rim member  102 . Accordingly, the body springs  201  can be reliably joined to the first rim member  101  and the second rim member  102 . This effect, for example, prevents the body springs  201  from coming off from the first rim member  101  and the second rim member  102 , even if the tire  1  is used in a special environment. Also, for example, if the elastic deformable portions  202  of the body springs  201  are directly joined to the first rim member  101  and the second rim member  102 , the elastic deformable portions  202  may easily fall off from the first rim member  101  and the second rim member  102 , depending on a method of joining or due to the wearing away of the elastic deformable portions  202 . In contrast to this, in the present embodiment, such a fear is less likely to occur because the latch portions  203  of a different shape from the elastic deformable portions  202  are latched. Furthermore, even in a case in which the tire  1  according to the present embodiment is used, for example, on a lunar surface where temperature largely varies, the body springs  201  are engaged in the engagement receiving portions  105  of the first rim member  101  and the second rim member  102 , so the occurrence of thermal expansion or thermal contraction in the first and second rim members  101  and  102  or the body springs  201  does not cause the body springs  201  to come off from the first rim member  101  and the second rim member  102 , thus facilitating maintaining the form and function of the tire  1 . 
     In addition, in a case in which the first rim member  101  and the second rim member  102  have the engagement receiving portions  105 , and the latch portions  203  of the body springs  201  are latched on the engagement receiving portions  105 , as in the present embodiment, the body springs  201  can be more reliably joined to the first rim member  101  and the second rim member  102 . 
     In addition, in a case in which a latched state of the latch portions  203  is maintained using the support members  104 , as in the present embodiment, the body springs  201  are further prevented from coming off from the first rim member  101  and the second rim member  102 . Therefore, the plurality of body springs  201  can be more reliably engaged in the engagement receiving portions  105  of the first rim member  101  and the second rim member  102 . 
     In the above embodiment, it is described that the latch portions  203  of the body spring  201  is configured to each include the straight portion  203   a  and the bent portion  203   b  disposed at the tip end of the straight portion  203   a . However, the configuration of the latch portions  203  is not necessarily limited thereto. The latch portions  203  may have any shape that is different from the shape of the elastic deformable portion  202  and is capable of being latched on the first rim member  101  and the second rim member  102 . The engagement receiving portions  105  of the first rim member  101  and the second rim member  102  may also have any configuration, corresponding to the configuration of the latch portions  203 . For example, the latch portions  203  may be formed in a linear shape. In this case, the first rim member  101  and the second rim member  102  may be provided with engagement receiving portions in which the linear latch portions  203  can be engaged, or the latch portions  203  may simply be secured by the support members  104 . 
     The latch portions  203  are not limited to the examples described herein, and may have any configuration capable of latching the body spring  201  on the first rim member  101  and the second rim member  102 . For example, the latch portions  203  may be each formed in a hook shape. 
     For example, in the above embodiment, it is described that the bent portion  203   b  of the latch portion  203  of the body spring  201  is bent orthogonally to the straight portion  203   a . However, the bent portion  203   b  does not necessarily have to be orthogonal to the straight portion  203   a . The bent portion  203   b  may be bent at a predetermined angle with respect to the straight portion  203   a . In this case, the engagement receiving portion  105  may be formed as a hole provided in a direction that matches the angle of bending of the bent portion  203   b.    
     As illustrated in  FIG. 10 , the latch portion  203  of the body spring  201  may be configured to include, for example, a straight portion  203   a  and a ring portion  203   c  disposed at a tip end of the straight portion  203   a . The ring portion  203   c  is formed in an annular shape having a through hole  203   d  in its center. In this case, the engagement receiving portion  105  may be configured to be, for example, a projection that can penetrate the through hole  203   d . In this case, by penetrating the projection of the engagement receiving portion  105  through the through hole  203   d  of the ring portion  203   c  of the latch portion  203 , the latch portion  203  can be latched on the engagement receiving portion  105 . 
     In the above embodiment, it is described that the elastic deformable portion  202  of the body spring  201  and the elastic deformable portion  212  of the interlink spring  211  are each constituted of a coil spring. However, the elastic deformable portion  202  of the body spring  201  and the elastic deformable portion  212  of the interlink spring  211  do not necessarily have to be constituted of a coil spring. For example, as illustrated in  FIG. 11 , the elastic deformable portion  202  of the body spring  201  and/or the elastic deformable portion  212  of the interlink spring  211  may be each configured to include a two-dimensional (i.e., extending along approximately the same plane) corrugated metal member, instead of a coil spring.  FIG. 11  illustrates an example of a case in which the elastic deformable portions  202  and the elastic deformable portions  212  are each formed in a two-dimensional corrugated shape. The corrugated metal member may be, for example, in the shape of a linked semicircle or a sinusoidal waveform. Even in this case, the body springs  201  and the interlink springs  211  can be interlinked by interlacing the corrugated metal members. 
     In the above embodiment, it is described that the interlink springs  211  are each interlaced with the two adjacent body springs  201 , but the tire  1  does not necessarily have to have the interlink springs  211 . For example, the tire  1  may have an interlink member  220  having two through holes  220   a , as illustrated in  FIG. 12 , and the interlink member  220  may be used to interlink the two adjacent body springs  201 . The two through holes  220   a  of the interlink member  220  each have a size sufficient to pass the body spring  201  therethrough. In this case, one body spring  201  passes through one of the two through holes  220   a  that the interlink member  220  has, and one body spring  201  adjacent to the one body spring  201  passes through the other. As illustrated in  FIG. 13 , by passing the interlink members  220  through the body springs  201  at a plurality of points, the two adjacent body springs  201  can be interlinked using the interlink members  220  at the plurality of points separated in the tire width direction. In  FIG. 13 , part of each of the interlink members  220 , which interlink the two body springs  201 , is illustrated in cross section so that a state of penetration of the body springs  201  through the through holes  220   a  can be seen. In this manner, the tire  1  can also be configured by using the interlink members  220 , instead of the interlink springs  211 . 
     Although the present disclosure has been described based on the drawings and examples, it is noted that a person skilled in the art can easily make various variations and modifications based on the present disclosure. Accordingly, it is noted that these variations and modifications are included in the scope of the present invention. For example, the functions and the like included in each of components and the like can be rearranged so as not to be logically inconsistent, and a plurality of components can be combined into one or divided. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  tire 
               10  wheel portion 
               20  grounding deformable portion 
               101  first rim member 
               102  second rim member 
               103  connection member 
               104  support member 
               105  engagement receiving portion 
               106  bolt 
               107  bolt hole 
               201  body spring 
               202 ,  212  elastic deformable portion 
               203  latch portion 
               203   a  straight portion 
               203   b  bent portion 
               203   c  ring portion 
               203   d  through hole 
               211  interlink spring 
               213  limitation portion 
               220  interlink member 
               220   a  through hole 
             A axis