Patent Publication Number: US-2021188151-A1

Title: Wheelchair fixing device for vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Patent Application No. 2019-229765 filed on Dec. 19, 2019, incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The disclosure relates to a wheelchair fixing device for a vehicle. 
     2. Description of Related Art 
     There is a hitherto known wheelchair fixing device that has a pressure-bearing part (a seat cushion in a flipped-up state) for rear wheels of a wheelchair that is provided on a rear side of a wheelchair placing region in a floor of a vehicle cabin, and lashing belts that couple the wheelchair and a vehicle body (anchors) together (see, e.g., Japanese Patent Application Publication No. 2017-148445). This wheelchair fixing device fixes a wheelchair as the lashing belts apply a tensile force directed toward a rear lower side to the wheelchair while the pressure-bearing part comes into pressure-contact with rear-wheel upper parts that are parts of the rear wheels of the wheelchair above an axle of the wheelchair. 
     SUMMARY 
     Some lashing belts are designed to fix a wheelchair to a vehicle body by having a hook, provided at one end thereof, hung on (engaged with) a metal frame of the wheelchair. Typically formed by a painted metal rod, such a hook is firmly engaged with the frame of the wheelchair by fastening the lashing belt so as to reduce its length after the hook is engaged with the frame. 
     Therefore, if one tries to detach the hook from the frame to detach the lashing belt, for example, without loosening the lashing belt, the hook does not easily slide over the frame, making it difficult to detach the hook from the frame. Moreover, since the metal hook is directly and firmly in contact with the metal frame, shaking (vibration) that the vehicle experiences may be directly transmitted to the wheelchair. When there is no passenger in a wheelchair, the lashing belt is left at a predetermined place. If the hook moves due to shaking (vibration) that the vehicle experiences, the hook may hit other parts around it and thereby damage those other parts or cause noise. 
     An object of the disclosure is to obtain a wheelchair fixing device for a vehicle that can increase the ease of the action of detaching a lashing belt from a frame of a wheelchair. 
     To achieve this object, a wheelchair fixing device for a vehicle according to the first aspect of the disclosure includes: a lashing belt having, at one end, a part-to-be-engaged that is configured to be able to engage with an engaging part exposed through a floor surface of a vehicle cabin; a hook that is provided at the other end of the lashing belt and configured to be able to engage with a frame of a wheelchair; and a hook cover that is formed by an elastic body into a tubular shape and fitted on an engaging region of the hook that is a region engaging with the frame. 
     In the disclosure according to the first aspect, the tubular hook cover formed by an elastic body is fitted on the engaging region of the hook that is the region engaging with the frame of the wheelchair. Therefore, when one tries to detach the hook from the frame to detach the lashing belt, for example, without loosening the lashing belt, one can slide the hook cover over the frame while elastically deforming the hook cover. This can increase the ease of the action of detaching the lashing belt from the frame of the wheelchair. 
     The wheelchair fixing device for a vehicle according to the second aspect is the wheelchair fixing device for a vehicle according to the first aspect, wherein the hook cover is made of urethane. 
     In the disclosure according to the second aspect, the hook cover is made of urethane. Thus, the weight of the hook cover can be reduced compared with when the hook cover is not made of urethane. 
     The wheelchair fixing device for a vehicle according to the third aspect is the wheelchair fixing device for a vehicle according to the first or second aspect, wherein: the engaging region of the hook includes a first curved section that continues from a base section to which the other end of the lashing belt is attached, a linear section that continues from the first curved section, and a second curved section that continues from the linear section; and the hook cover has slits, extending along a circumferential direction, in an outer circumferential surface on a tensile deformation side and an outer circumferential surface on a compressive deformation side that respectively correspond to the first curved section and the second curved section. 
     In the disclosure according to the third aspect, the hook cover has the slits, extending along the circumferential direction, in the outer circumferential surface on the tensile deformation side and the outer circumferential surface on the compressive deformation side that respectively correspond to the first curved section and the second curved section. This allows the hook cover to deform elastically along the first curved section and the second curved section so as to come into close contact with the first curved section and the second curved section. 
     The wheelchair fixing device for a vehicle according to the forth aspect is the wheelchair fixing device for a vehicle according to the third aspect, wherein the slits formed in the outer circumferential surface on the tensile deformation side have a linear shape as seen in a sectional view taken along an axial direction of the hook cover in a state of not being fitted on the hook, while the slits formed in the outer circumferential surface on the compressive deformation side have an inverted V-shape as seen in a sectional view taken along the axial direction of the hook cover in a state of not being fitted on the hook. 
     In the disclosure according to the fourth aspect, the slits formed in the outer circumferential surface on the tensile deformation side have a linear shape, while the slits formed in the outer circumferential surface on the compressive deformation side have an inverted V-shape, as seen in a sectional view taken along the axial direction of the hook cover in a state of not being fitted on the hook. This allows the hook cover to deform elastically along the first curved section and the second curved section more effectively so as to come into closer contact with the first curved section and the second curved section. 
     The wheelchair fixing device for a vehicle according to the fifth aspect is the wheelchair fixing device for a vehicle according to any one of the first aspect to the fourth aspect, wherein parts of an inner circumferential surface of the hook cover at ends in an axial direction are bonded to an outer circumferential surface of the hook by an adhesive. 
     In the disclosure according to the fifth aspect, the parts of the inner circumferential surface of the hook cover at the ends in the axial direction are bonded to the outer circumferential surface of the hook by the adhesive. This can restrain the hook cover from shifting out of the engaging region of the hook that is the region engaging with the frame of the wheelchair. 
     As has been described above, the disclosure can increase the ease of the action of detaching the lashing belt from the frame of the wheelchair. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein: 
         FIG. 1  is a plan view showing a state where a wheelchair fixing device for a vehicle according to an embodiment fixes a wheelchair; 
         FIG. 2  is a front view showing a main part of the wheelchair fixing device for a vehicle according to the embodiment; 
         FIG. 3  is a perspective view showing a hook cover of the wheelchair fixing device for a vehicle according to the embodiment; 
         FIG. 4  is a front sectional view showing the hook cover of the wheelchair fixing device for a vehicle according to the embodiment; 
         FIG. 5  is a sectional view taken along line X-X of  FIG. 4 , showing the hook cover of the wheelchair fixing device for a vehicle according to the embodiment; 
         FIG. 6  is a sectional view taken along line Y-Y of  FIG. 4 , showing the hook cover of the wheelchair fixing device for a vehicle according to the embodiment; 
         FIG. 7  is a front sectional view corresponding to  FIG. 4 , showing slits that are formed in the hook cover of the wheelchair fixing device for a vehicle according to the embodiment; 
         FIG. 8  is a sectional view showing, in close-up, the hook cover attached to a hook of the wheelchair fixing device for a vehicle according to the embodiment; 
         FIG. 9  is a sectional view showing, in close-up, a state where the hook cover of the wheelchair fixing device for a vehicle according to the embodiment is engaged with a frame of a wheelchair; 
         FIG. 10A  is a perspective view showing a step of attaching, to an anchor, a part-to-be-engaged provided at one end of a lashing belt of the wheelchair fixing device for a vehicle according to the embodiment; and 
         FIG. 10B  is a perspective view showing a state where the part-to-be-engaged provided at the one end of the lashing belt of the wheelchair fixing device for a vehicle according to the embodiment is attached to the anchor. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     An embodiment according to the disclosure will be described in detail below based on the drawings. A wheelchair fixing device  10  for a vehicle according to the embodiment is used for a passenger P in a wheelchair  60  who got on a bus  12  that is one example of passenger carrying vehicles (see  FIG. 1 ). (The term “bus” here covers vehicles used for Mobility-as-a-Service (Maas) represented by self-driving buses.) 
     For the convenience of illustration, the arrows UP, FR, and RH shown as necessary in the drawings indicate a vehicle body upward direction, a vehicle body frontward direction, and a vehicle body rightward direction of the bus  12 , respectively. Unless otherwise noted, the directions of up and down, front and rear, and left and right mentioned in the following description mean up and down in a vehicle body up-down direction, front and rear in a vehicle body front-rear direction, and left and right in a vehicle body left-right direction (vehicle width direction). 
     As shown in  FIG. 1 , a wheelchair space  16  is set in a floor surface  14  of a vehicle cabin S of the bus  12 . The floor surface  14  of the vehicle cabin S here refers to an upper surface of a floor carpet laid on a floor panel as a floor, and in this upper surface of the floor carpet, rectangular frames having a long side thereof directed in the front-rear direction are indicated side by side in the left-right direction. 
     The wheelchair space  16  is marked with a wheelchair sign (not shown) at a substantially central part such that passengers can see at a glance that that spot is a boarding position for a passenger P in the wheelchair  60 . On the rear side of the wheelchair space  16 , a plurality of seats  18  in which other passengers (not shown) than the passenger Pin the wheelchair  60  can sit in a semi-standing posture is integrally provided in a row in the vehicle width direction. 
     An anchor  20  serving as an engaging part that detachably engages a part-to-be-engaged  32  provided at one end of a lashing belt  30  to be described later is exposed through the floor surface  14  of the vehicle cabin S. The floor carpet has a hole (not shown) through which the anchor  20  is exposed. 
     The lashing belt  30  is attached to the wheelchair  60  that got on board in the wheelchair space  16 . The part-to-be-engaged  32  made of metal and configured to be able to engage with the metal anchor  20  is provided at the one end of the lashing belt  30 , while a hook  40  made of metal and configured to be able to engage with a cylindrical metal frame  62  of the wheelchair  60  is provided at the other end of the lashing belt  30 . 
     As shown in  FIG. 10A , the anchor  20  has: a disc-shaped main body  22 ; a front-side projection  24  that extends from a front-side circumferential edge of the main body  22  such that a central portion of the front-side projection  24  in the vehicle width direction projects farther toward an upper rear side than both end portions thereof in the vehicle width direction; and a rear-side projection  26  that extends from a rear-side circumferential edge of the main body  22  such that a central portion of the rear-side projection  26  in the vehicle width direction projects farther toward an upper front side than both end portions thereof in the vehicle width direction. 
     The part-to-be-engaged  32  has a main body  34 , a columnar rod  36  provided at a central portion of the main body  34  so as to be movable in the up-down direction, a disc-shaped pressing part  38  provided at a lower end of the rod  36 , integrally and coaxially with the rod  36 , and a coil spring (not shown) that is provided between the main body  34  and the rod  36  and urges the pressing part  38  upward. 
     A pair of left and right flat-plate-shaped engaging parts  35  is provided on a lower surface of the main body  34 , integrally with and perpendicularly to the main body  34 , with a thickness direction thereof directed in the vehicle width direction, and the pressing part  38  can be housed between the engaging parts  35 . An interval between the pair of left and right engaging parts  35  is larger than the outside diameter of the pressing part  38 . A ring  28  is provided at an upper portion of the rod  36 , and one end of the lashing belt  30  is passed through and attached to the ring  28 . 
     As shown in  FIG. 2 , the hook  40  provided at the other end of the lashing belt  30  is formed by bending a columnar rod into a substantially S-shape, and has: a substantially annular base section  42  which the other end of the lashing belt  30  is passed through and attached to; a first curved section  44  that continues from the base section  42 ; a linear section  45  that continues from the first curved section  44 ; a second curved section  46  that continues from the linear section  45 ; and a linear leading end section  48  that continues from the second curved section  46 . 
     A hook cover  50  is attached to the hook  40 . As shown in  FIG. 3  to  FIG. 6 , the hook cover  50  is formed by an elastic body having an energy absorbing function, such as urethane (e.g., PE-Lite® manufactured by Inoac Corporation) into a cylindrical shape, and in some embodiments, the hook cover  50  is made of urethane. 
     The urethane hook cover  50  has hardness T within the range of, for example, 0.01 kN&lt;T&lt;0.5 kN. While it depends on the shape, outside diameter, etc. of the hook  40 , the hook cover  50  has, for example, an axial length L (see  FIG. 4 ) of 75 mm to 100 mm, an outside diameter Ro (see  FIG. 6 ) of 20 mm to 25 mm, and an inside diameter Ri (see  FIG. 6 ) of 8 mm to 10 mm. 
     As shown in  FIG. 2 , the hook cover  50  is fitted and fixed on the hook  40  so as to be entirely disposed inside an engaging region E of the hook  40  that is a region engaging with the frame  62 . The engaging region E is a region stretching from a border (a point at which the curvature of the first curved section  44  starts)  43  between the base section  42  and the first curved section  44  toward the leading end section  48  (up to an end surface  48 A of the leading end section  48 ), and the hook cover  50  is fitted at such a position as to cover at least a portion of the first curved section  44  on the side of the linear section  45 , the linear section  45 , and the second curved section  46 . 
     Hereinafter, one end of the hook cover  50  on the side of the base section  42  in the axial direction will be referred to as “one end  51 ,” and the other end of the hook cover  50  on the side of the leading end section  48  in the axial direction will be referred to as “the other end  52 .” As shown in  FIG. 8 , an end surface  52 A of the other end  52  of the hook cover  50  is located, on a compressive deformation side to be described later, at a border (a point at which the curvature of the second curved section  46  ends)  47  between the second curved section  46  and the leading end section  48 . 
     As shown in  FIG. 4  to  FIG. 6 , parts of an inner circumferential surface of the hook cover  50  at the one end  51  and the other end  52  are fixed by being bonded to parts of an outer circumferential surface of the hook  40  at the first curved section  44  and the second curved section  46 , respectively, by double-sided tapes  58  as an adhesive. 
       FIG. 4  to  FIG. 6  show a state where an adhesive surface on one side of each double-sided tape  58  is stuck to the corresponding part of the inner circumferential surface of the hook cover  50  at the one end  51  or the other end  52 , while a release paper  59  remains on the other adhesive surface of each double-sided tape  58 . To bond and fix the hook cover  50  to the hook  40  by the double-sided tapes  58 , the hook cover  50  is fitted inside the engaging region E of the hook  40  and then the release papers  59  are peeled off to bond the two together. 
     As shown in  FIG. 5 , the release papers  59  protrude from end surfaces of the one end  51  and the other end  52  of the hook cover  50  toward outer sides in the axial direction by a predetermined length H (e.g., H=10 mm) such that one can pinch the release papers  59  with his or her fingers. In the sectional plan view shown in  FIG. 5 , the adhesive surface of each double-sided tape  58  has a width W of, for example, 5 mm to 10 mm, and a length D along the axial direction of, for example, 5 mm to 20 mm. 
     As shown in  FIG. 7 , the hook cover  50  has pluralities of slits  54 ,  56 , extending along a circumferential direction, in predetermined regions G on an inner side in the axial direction relative to the one end  51  and the other end  52 . Specifically, the regions G include regions that are subjected to tensile deformation by the first curved section  44  and the second curved section  46  and regions that are subjected to compressive deformation by these sections. For example, six slits  54  are formed in each tensile deformation-side region of the outer circumferential surface, and for example, four slits  56  are formed in each compressive deformation-side region of the outer circumferential surface. 
     The slits  54  formed in the outer circumferential surface on a tensile deformation side are formed by making linear incisions in a direction perpendicular to the axial direction of the hook cover  50  as seen in a front sectional view taken along the axial direction thereof in a state of not being fitted on the hook  40 . The slits  56  formed in the outer circumferential surface on a compressive deformation side are formed by making inverted V-shaped notches as seen in a front sectional view taken along the axial direction of the hook cover  50  in a state of not being fitted on the hook  40 . For example, the slits  54  are formed at 7 mm to 10 mm intervals in the axial direction, while the slits  56  are formed at 10 mm to 12 mm intervals in the axial direction when a maximum notch width K in the outer circumferential surface is 2 mm to 3 mm. 
     Those parts of the hook cover  50  that are located on the outer side from the slits  54 ,  56  (regions G) in the axial direction have a length J of, for example, 8 mm to 12 mm. When sticking the double-sided tapes  58  to the parts of the inner circumferential surface of the hook cover  50  at the one end  51  and the other end  52  is taken into account, the slits  54 ,  56  do not reach the inner circumferential surface of the hook cover  50  but may reach the inner circumferential surface. The slits  54 ,  56  are omitted from the drawings other than  FIG. 7 . 
     It is assumed that the bus  12  in this embodiment runs in a special lane at a speed of 20 km per hour or less. Therefore, even if a load directed frontward is applied to the wheelchair  60 , for example, in the event of sudden braking of the bus  12 , one lashing belt  30  for each wheelchair  60  is sufficient to fix the wheelchair  60  to the bus  12 . 
     Described next are the workings of the wheelchair fixing device  10  for a vehicle according to the embodiment configured as has been described above. 
     As shown in  FIG. 2  and  FIG. 8 , first, the hook cover  50  is attached to the hook  40 . The hook cover  50  is fitted inside the engaging region E of the hook  40 . Specifically, the hook cover  50  is disposed so as to cover a portion of the first curved section  44  on the side of the linear section  45 , the linear section  45 , and the second curved section  46 . 
     Then, the release papers  59  of the double-sided tapes  58  stuck to the parts of the inner circumferential surface of the hook cover  50  at the one end  51  and the other end  52  are peeled off, and those parts of the inner circumferential surface of the hook cover  50  at the one end  51  and the other end  52  are bonded to the parts of the outer circumferential surface at the first curved section  44  and the second curved section  46  to thereby fix the hook cover  50  to the hook  40 . 
     Thus, the hook cover  50  can be effectively restrained or prevented from shifting out of the engaging region E of the hook  40 . More specifically, the hook cover  50  can be effectively restrained or prevented from shifting to such a position that the one end  51  is located beyond the border  43  between the base section  42  and the first curved section  44 , or to such a position that the other end  52  is located beyond the leading end section  48 . 
     When the hook cover  50  is fixed to the hook  40 , the regions G on the inner side of the hook cover  50  relative to the one end  51  and the other end  52  in the axial direction are curved along the first curved section  44  and the second curved section  46 . Since the slits  54 ,  56  are formed in these regions G (see  FIG. 7 ), the parts of the inner circumferential surface of the hook cover  50  at the one end  51  and the other end  52  can be brought into close contact with the parts of the outer circumferential surface at the first curved section  44  and the second curved section  46 . (The inner circumferential surface can be kept from lifting off the outer circumferential surface.) 
     In particular, the slits  54  formed on the tensile deformation side have a linear shape as seen in a front sectional view taken along the axial direction of the hook cover  50  in a state of not being fitted on the hook  40 , so that the tensile deformation-side regions G can effectively elastically deform such that the slits  54  widen along the first curved section  44  and the second curved section  46 . Thus, the parts of the inner circumferential surface of the hook cover  50  at the one end  51  and the other end  52  on the tensile deformation side can be brought into closer contact with the parts of the outer circumferential surface at the first curved section  44  and the second curved section  46 . 
     The slits  56  formed on the compressive deformation side have an inverted V-shape as seen in a front sectional view taken along the axial direction of the hook cover  50  in a state of not being fitted on the hook  40 , so that the compressive deformation-side regions G can effectively elastically deform such that the slits  56  narrow along the first curved section  44  and the second curved section  46 . Thus, the parts of the inner circumferential surface of the hook cover  50  at the one end  51  and the other end  52  on the compressive deformation side can be brought into closer contact with the parts of the outer circumferential surface at the first curved section  44  and the second curved section  46 . 
     When the hook cover  50  is thus fixed inside the engaging region E of the hook  40 , the hook  40  is hung on the frame  62  of the wheelchair  60  (see  FIG. 1 ). Specifically, the hook cover  50  disposed in the engaging region E of the hook  40  is hung on (engaged with) the frame  62 . Then, as shown in  FIG. 9 , a part of the hook cover  50  is elastically deformed and the frame  62  digs into the hook cover  50 . Thus, the hook  40  can be stably kept in position relative to the frame  62  even in an emergency such as sudden braking of the bus  12 . 
     Since the hook  40  is engaged with the frame  62  through the hook cover  50  that is made of urethane having an energy absorbing function, the hook  40  is not directly in contact with the frame  62 . (The hook cover  50  with a remaining thickness M is interposed between the hook  40  and the frame  62 .) Thus, shaking (vibration) that the bus  12  experiences can be hindered by the hook cover  50  from being directly transmitted to the wheelchair  60  through the lashing belt  30 . 
     Since the hook  40  is not directly in contact with the frame  62 , when one tries to detach the hook  40  from the frame  62  to detach the lashing belt  30 , for example, without loosening the lashing belt  30 , one can slide the hook cover  50  over the frame  62  while elastically deforming the hook cover  50 . Specifically, the hook cover  50  can be slid while being elastically deformed with a force of, for example, 0.01 kN. Thus, the hook  40  can be easily detached from the frame  62 . (The ease of the action of detaching the lashing belt  30  from the frame  62  can be increased.) 
     Since the hook cover  50  according to the embodiment extends only to such a position that the end surface  52 A of the other end  52  thereof on the compressive deformation side reaches the border  47  between the second curved section  46  and the leading end section  48  that is the point at which the curvature of the second curved section  46  ends in the hook  40 , the hook  40  can be more easily detached from the frame  62 . (The ease of the action of detaching the lashing belt  30  from the frame  62  can be further increased.) 
     Specifically, if, for example, the hook cover  50  extends to such a position that the end surface  52 A of the other end  52  on the compressive deformation side reaches the end surface  48 A of the leading end section  48  of the hook  40 , it is somewhat difficult to detach the leading end section  48  of the hook  40  from the frame  62  due to the increased area of contact (sliding resistance) between the frame  62  and the other end  52  of the hook cover  50  covering the leading end section  48  as a result of elastic deformation of the other end  52  of the hook cover  50 . 
     By contrast, as described above, the hook cover  50  according to the embodiment extends only to such a position that the end surface  52 A of the other end  52  on the compressive deformation side reaches the border  47  in the hook  40 , and the leading end section  48  of the hook  40  is exposed without being covered by the hook cover  50 . Thus, it is easy to detach the leading end section  48  of the hook  40  from the frame  62  because the area of contact between the leading end section  48  and the frame  62  is that of a minute point between arc surfaces that intersect and come into contact with each other and therefore small. 
     When there is no passenger Pin the wheelchair  60  on board, the lashing belt  30  is left at a predetermined place. Therefore, the lashing belt  30  and the hook  40  may move due to shaking (vibration) that the bus  12  experiences. Here, the hook  40  is provided with the urethane hook cover  50  as described above. 
     Therefore, even if the hook  40  moves and the hook cover  50  hits other parts around it (e.g., the wheelchair  60 , the floor surface  14 , or a wall surface such as a side wall of the vehicle cabin S), the hook cover  50  is unlikely to damage those other parts or cause noise. Moreover, since the hook cover  50  is made of urethane, the weight of the hook cover  50  can be reduced compared with when the hook cover  50  is not made of urethane. In addition, when the hook cover  50  deteriorates, it can be replaced. 
     The part-to-be-engaged  32  of the lashing belt  30  is detachably engaged with the anchor  20  as follows: As shown in  FIG. 10A , with the rod  36  pressed downward against the urging force of the coil spring, the pressing part  38  is inserted into a gap (insertion opening) between the main body  22  of the anchor  20  on one side and the front-side projection  24  and the rear-side projection  26  thereof on the other side, from an inner side or an outer side in the vehicle width direction. Then, the rod  36  is released from the downward pressure at a central portion of the anchor  20 . 
     Thus, as shown in  FIG. 10B , the engaging parts  35  engage (enter) on left and right sides of the front-side projection  24  and the rear-side projection  26 , and upper end portions of the front-side projection  24  and the rear-side projection  26  are held between an upper surface of the pressing part  38  and a lower surface of the main body  34  by the urging force of the coil spring. Thus, the part-to-be-engaged  32  of the lashing belt  30  can be engaged in a state where movement of the part-to-be-engaged  32  in the upward, downward, frontward, rearward, leftward, and rightward directions relative to the anchor  20  is limited. 
     To detach the part-to-be-engaged  32  of the lashing belt  30  from the anchor  20 , the rod  36  is pressed downward against the urging force of the coil spring. In this state, the pressing part  38  is pulled out of the gap between the main body  22  of the anchor  20  on one side and the front-side projection  24  and the rear-side projection  26  thereof on the other side. 
     While the wheelchair fixing device  10  for a vehicle according to the embodiment has been described above based on the drawings, the wheelchair fixing device  10  for a vehicle according to the embodiment is not limited to that shown in the drawings and design changes can be made thereto as necessary within the scope of the gist of the disclosure. For example, the hook cover  50  is not limited to that made of urethane, and the adhesive is not limited to the double-sided tape  58 . 
     The double-sided tape  58  as the adhesive may be provided at only one of the one end  51  and the other end  52  of the hook cover  50  instead of both the one end  51  and the other end  52 . The dimensions of the parts of the hook cover  50  and the numbers of the slits  54 ,  56  mentioned above are merely examples and the dimensions and numbers are not limited thereto. Design changes can be made as necessary to the dimensions of the parts of the hook cover  50  and the numbers of the slits  54 ,  56  according to the shape, the outside diameter, etc. of the hook  40 .