Abstract:
There is provided a tonneau cover apparatus including: a winding shaft that winds up a tonneau cover; an elongated shaped case that accommodates the winding shaft; support members provided at one end portion and another end portion of the case, and supporting the winding shaft; a retention member provided at the one end portion and/or the other end portion of the case and including an outer wall portion that covers the support member; and blocking portions provided at the support member and the retention member at the at least one end portion, the blocking portions being disposed at the inner side relative to the outer wall portion, and blocking movement of the retention member outward in the axial direction of the winding shaft from the engaging position by abutting against one another at the engaging position.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2011-007190 filed on Jan. 17, 2011, the disclosure of which is incorporated by reference herein. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a tonneau cover apparatus that is equipped with a retention member movably provided at one or both of one end portion and another end portion of a case. 
         [0004]    2. Related Art 
         [0005]    In a tonneau cover apparatus according to Japanese Patent Application Laid-Open (JP-A) No. 2009-23438, a winding shaft, round which a tonneau cover is wound, is accommodated inside a tonneau cover case, and inner holders are mounted at each of two end portions of the tonneau cover case. The inner holders turnably support the winding shaft, and a protrusion is formed at an outer periphery portion of each inner holder. 
         [0006]    Outer holders are also mounted at the two end portions of the tonneau cover case. The outer holders are mounted to cover the inner holders and to be movable in the axial direction of the winding shaft. Hence, by the outer holders being moved and the length direction length of the tonneau cover apparatus being shortened, the tonneau cover apparatus may be mounted in a vehicle. 
         [0007]    A long hole is formed penetrating through an outer periphery wall of each outer holder. The protrusion of the inner holder is accommodated in the long hole, and movement of the outer holder is blocked by the protrusion abutting against an inner periphery face at one length direction end of the long hole. Thus, detachment of the outer holder from the tonneau case is prevented. 
         [0008]    In this tonneau cover apparatus, as described above, the long holes are formed penetrating through the outer periphery walls of the outer holders and are exposed to the exterior. As a result, the external appearance of the tonneau cover apparatus is affected. 
       SUMMARY 
       [0009]    In consideration of the circumstances described above, an object of the present invention is to provide a tonneau cover apparatus capable of preventing detachment of a retention member from a case, while restraining effects on the external appearance of the tonneau cover apparatus. 
         [0010]    The first aspect of the present invention provides a tonneau cover apparatus including: 
         [0011]    a winding shaft that winds up a tonneau cover by turning in a winding direction, the tonneau cover covering a luggage compartment of a vehicle; 
         [0012]    an elongated shaped case that accommodates the winding shaft thereinside; 
         [0013]    support members that are provided at one end portion and another end portion of the case, the support members turnably supporting the winding shaft; 
         [0014]    a retention member provided at least one of the one end portion or the other end portion of the case, the retention member including an outer wall portion that covers the support member and being retained to be movable inward in an axial direction of the winding shaft from an engaging position; and 
         [0015]    a pair of blocking portions that are provided at the support member and the retention member at the at least one end portion, the blocking portions being disposed at the inner side relative to the outer wall portion, and blocking movement of the retention member outward in the axial direction of the winding shaft from the engaging position by abutting against one another at the engaging position. 
         [0016]    In the tonneau cover apparatus of the first aspect of the invention, the winding shaft round which the tonneau cover is wound is accommodated inside the case, and the winding shaft is supported to be turnable by the support members provided at the one end portion and the other end portion of the case. The retention member is provided at either or both of the one end portion and the other end portion of the case. The retention member includes the outer wall portion that covers the support member, and the retention member is supported to be movable inward from the engaging position in the axial direction of the winding shaft. 
         [0017]    The blocking portions are provided at both of the support member and the retention member. By the blocking portions abutting against one another at the engaging position, movement of the retention member outward from the engaging position in the winding shaft axial direction is blocked. Therefore, detachment of the retention member from the case is prevented. 
         [0018]    The blocking portions are disposed at the inner side relative to the outer wall portion. Therefore, the blocking portions of the support member and the retention member are not exposed to the exterior by the outer wall portion of the retention member. 
         [0019]    The second aspect of the present invention provides the tonneau cover apparatus according to the first aspect, further including: 
         [0020]    a shaft portion that is provided at either one of the support member or the retention member, one of the blocking portions being formed at the shaft portion; and 
         [0021]    a shaft-receiving portion that is provided at the other of the support member or the retention member, the other of the blocking portions being formed at the shaft-receiving portion and the shaft portion being slidably inserted into the shaft-receiving portion. 
         [0022]    In the tonneau cover apparatus of the second aspect of the invention, the shaft portion is slidably inserted into the shaft-receiving portion, one of the blocking portions is formed at the shaft portion, and the other of the blocking portions is formed at the shaft-receiving portion. Consequently, when the retention member moves inward in the winding shaft axial direction, the shaft-receiving portion guides the shaft portion. 
         [0023]    The third aspect of the present invention provides the tonneau cover apparatus according to the second aspect, further including a long hole that is formed in the shaft-receiving portion, a length direction of the long hole being along the axial direction of the winding shaft, wherein one of the blocking portions is accommodated in the long hole to be movable in the axial direction of the winding shaft, and the other of the blocking portions is a face at one length direction end of the long hole. 
         [0024]    In the tonneau cover apparatus of the third aspect of the invention, the long hole whose length direction is in the axial direction of the winding shaft is formed in the shaft-receiving portion, and the one blocking portion is accommodated in the long hole to be movable in the winding shaft axial direction. At the engaging position, the one blocking portion is abutted against one side face in the length direction of the long hole (i.e., the other blocking portion). Thus, movement of the retention member outward in the winding shaft axial direction is blocked. 
         [0025]    The fourth aspect of the present invention provides the tonneau cover apparatus according to the second aspect or the third aspect, wherein the shaft portion and the shaft-receiving portion are disposed at a central portion of the retention member with respect to directions orthogonal to the axis direction. 
         [0026]    In the tonneau cover apparatus of the fourth aspect of the invention, the shaft portion and the shaft-receiving portion are disposed at the central portion of the retention member. Therefore, the retention member may be more easily moved along the axial direction of the shaft portion and the shaft-receiving portion. 
         [0027]    The fifth aspect of the present invention provides the tonneau cover apparatus according to any one of the second though fourth aspects, further including an urging member that is disposed between the support member and the retention member, the shaft portion and the shaft-receiving portion being inserted through the urging member, and the urging member urging the retention member outward in the axial direction of the winding shaft. 
         [0028]    In the tonneau cover apparatus of the fifth aspect of the invention, the urging member is provided between the support member and the retention member, and the shaft portion and the shaft-receiving portion are inserted through the urging member. Therefore, the position of the urging member is specified by the shaft portion and the shaft-receiving portion, and slanting of the urging member is suppressed. In addition, urging force of the urging member acts along the axial direction of the shaft portion and the shaft-receiving portion. 
         [0029]    According to the tonneau cover apparatus of the first aspect of the present invention, detachment of the retention member from the case may be prevented while effects on the external appearance of the tonneau cover apparatus are restrained. 
         [0030]    According to the tonneau cover apparatus of the second aspect of the invention, when the retention member is moving inward in the axial direction of the winding shaft, the shaft portion and shaft-receiving portion may prevent detachment of the retention member from the case and the shaft-receiving portion may guide the shaft portion. 
         [0031]    According to the tonneau cover apparatus of the third aspect of the invention, detachment of the retention member from the case may be prevented with a simple structure. 
         [0032]    According to the tonneau cover apparatus of the fourth aspect of the invention, when the retention member is being moved inward in the axial direction of the winding shaft, the retention member may be moved smoothly. 
         [0033]    According to the tonneau cover apparatus of the fifth aspect of the invention, mounting characteristics when the urging member is being mounted may be improved. In addition, when the retention member is being moved inward in the axial direction of the winding shaft, the retention member may be moved even more smoothly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]    Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
           [0035]      FIG. 1  is a sectional diagram in which a tonneau cover apparatus relating to an exemplary embodiment of the present invention is partially cut away; 
           [0036]      FIG. 2  is a perspective view illustrating a right end portion of the tonneau cover apparatus relating to the exemplary embodiment of the present invention; 
           [0037]      FIG. 3  is a partially cut away perspective diagram illustrating the right end portion of the tonneau cover apparatus relating to the exemplary embodiment of the present invention; 
           [0038]      FIG. 4  is a perspective diagram illustrating a state in which the right end portion of the tonneau cover apparatus relating to the exemplary embodiment of the present invention is disassembled; 
           [0039]      FIG. 5  is a sectional diagram in which an outer cover and an inner cover used in the exemplary embodiment of the present invention are partially cut away; 
           [0040]      FIG. 6  is a sectional diagram in which an outer cover and an inner cover used in the exemplary embodiment of the present invention are partially cut away; and 
           [0041]      FIG. 7  is a sectional diagram in which an outer cover and an inner cover used in the exemplary embodiment of the present invention are partially cut away. 
       
    
    
     DETAILED DESCRIPTION 
       [0042]      FIG. 1  shows a sectional diagram of a tonneau cover apparatus  10  relating to an exemplary embodiment of the present invention. In the drawings, upward of the tonneau cover apparatus  10  is indicated by the arrow UP, rightward of the tonneau cover apparatus  10  is indicated by the arrow RH, and forward of the tonneau cover apparatus  10  is indicated by the arrow FR. 
         [0043]    As illustrated in  FIG. 1 , a right end portion (one end portion) and a left end portion (other end portion) of the tonneau cover apparatus  10  are symmetrical structures about a left-right direction central portion of the tonneau cover apparatus  10 . Accordingly, in regard to the right end portion and the left end portion of the tonneau cover apparatus  10 , the right end portion of the tonneau cover apparatus  10  is described and no description is given of the left end portion of the tonneau cover apparatus  10 . 
         [0044]    As illustrated in  FIG. 1  to  FIG. 3 , the tonneau cover apparatus  10  is provided with a case  12  substantially in an elongated shaped tube shape. A cross-sectional shape of the case  12  is a substantially rectangular shape of which a portion is opened. A slit  14  is formed penetrating through a rear wall portion of the case  12 . The slit  14  is arranged along the left-right direction. 
         [0045]    As illustrated in  FIG. 4  and  FIG. 5 , an inner cover  16  made of resin is provided at the right end portion of the case  12 . The inner cover  16 , which has the shape of a rectangular tube with a floor, serves as a support member. The inner cover  16  is opened to rightward, and a flange  18  is provided at the opening portion of the inner cover  16 . The inner cover  16  is inserted into the case  12  and, in a state in which the flange  18  is abutted against a right edge portion of the case  12 , the inner cover  16  is mounted to the case  12 . Thus, the right end portion of the case  12  is closed off by the inner cover  16 . A support shaft  20  with a substantially circular rod shape is provided at a central portion of the floor wall of the inner cover  16 . The support shaft  20  protrudes to leftward from the floor wall of the inner cover  16 . 
         [0046]    A tube portion  22  is provided at a central portion of the floor wall of the inner cover  16 . The tube portion  22 , which has the shape of a substantially cross-shaped hollow tube, serves as a shaft-receiving portion. The tube portion  22  protrudes to rightward from the floor wall of the inner cover  16 . The tube portion  22  is opened to rightward and is disposed to be coaxial with the support shaft  20 . A long hole  26  with a substantially rectangular shape is formed penetrating through a rear side wall  24  of the tube portion  22 . The long hole  26  is arranged with the length direction thereof along the axial direction of the support shaft  20 . A right side face of an inner periphery face of the long hole  26  is an abutting face  26 A that serves as a blocking portion. Another substantially rectangular long hole  30  is formed penetrating through a front side wall  28  of the tube portion  22 . The long hole  30  is arranged with the length direction thereof along the axial direction of the support shaft  20 . A right side face of the inner side face of the long hole  30  is an abutting face  30 A that serves as a blocking portion. 
         [0047]    As illustrated in  FIG. 1 , a winding shaft  32  with a substantially circular tube shape is disposed inside the case  12 . The winding shaft  32  is disposed to be coaxial with the support shaft  20  of the inner cover  16 , and is supported at the support shaft  20  to be turnable. One end of a tonneau cover in the form of a sheet (not illustrated) is fixed to the winding shaft  32 . When the winding shaft  32  is turned one way about the axis (hereinafter referred to as the winding direction), the tonneau cover is wound from the one end thereof onto an outer periphery portion of the winding shaft  32  in layers. Then, when the other end of the tonneau cover is pulled, the tonneau cover is pulled out through the slit  14  of the case  12  while the winding shaft  32  turns the other way about the axis (hereinafter referred to as the unwinding direction). 
         [0048]    A coil spring  34  is disposed inside the winding shaft  32 . One end of the coil spring  34  is anchored at the support shaft  20  of the inner cover  16 , and the other end of the coil spring  34  is anchored at the winding shaft  32 . The coil spring  34  urges the winding shaft  32  in the winding direction. 
         [0049]    As illustrated in  FIG. 1  to  FIG. 5 , an outer cover  40  made of resin is provided at the right end portion of the case  12 . The outer cover  40  serves as a retention member. A floor wall  42  with a substantially rectangular plate shape is disposed at a rightward portion of the outer cover  40 . The floor wall  42  serves as an outer wall portion. A peripheral wall  44  is provided integrally with an outer periphery portion of the floor wall  42 . The peripheral wall  44 , which has a substantially rectangular tube shape, also serves as the outer wall portion. The peripheral wall  44  protrudes leftward from the floor wall  42 . 
         [0050]    A boss  46  in the shape of a substantially cross-shaped hollow tube is provided at a central portion of the floor wall  42  of the outer cover  40 . The boss  46  serves as a shaft portion. The boss  46  protrudes to leftward from the floor wall  42 . The boss  46  is formed with an outer profile thereof being a little smaller than an inner profile of the inner periphery portion of the tube portion  22 . A hook  48  is provided at a rearward portion of a distal end portion of the boss  46 . The hook  48 , which has a triangular shape in cross-section as viewed from above, serves as a blocking portion. The hook  48  protrudes rearward from the boss  46 . A hook  50  is provided at a frontward portion of the distal end portion of the boss  46 . The hook  50 , which has a triangular shape in cross-section as viewed from above, serves as a blocking portion. The hook  50  protrudes forward from the boss  46 . 
         [0051]    The boss  46  is inserted into the tube portion  22  of the inner cover  16 . The hook  48  and hook  50  of the boss  46  are accommodated in the long hole  26  and the long hole  30 , respectively, of the tube portion  22 . Thus, the boss  46  and the tube portion  22  are disposed at the inner side of the outer cover  40  relative to the floor wall  42  and peripheral wall  44  of the outer cover  40 , and are prevented from being exposed to the exterior by the peripheral wall  44  and the floor wall  42 . 
         [0052]    The hook  48  and the hook  50  are abutted against the abutting face  26 A of the long hole  26  and the abutting face  30 A of the long hole  30 , respectively. Thus, movement of the outer cover  40  in the left-right direction (i.e., in the outward direction of the winding shaft  32  axial direction) is blocked at a first position that serves as an engaging position. Thus, detachment of the outer cover  40  from the case  12  is prevented. Meanwhile, the boss  46  is slidable in the left-right direction at the inner periphery portion of the tube portion  22 , and the hook  48  and the hook  50  are movable in the left-right direction in the long hole  26  and the long hole  30 , respectively, of the tube portion  22 . Thus, the outer cover  40  is constituted to be movable leftward from the first position (in the inward direction of the winding shaft  32  axial direction) and to be movable until a distal end portion of the tube portion  22  of the inner cover  16  is abutted against the floor face of the outer cover  40  (hereinafter, this position is referred to as a second position). 
         [0053]    A substantially helical compression coil spring  52  spans between the floor wall of the inner cover  16  and the floor wall  42  of the outer cover  40 . The compression coil spring  52  serves as an urging member. The tube portion  22  of the inner cover  16  and the boss  46  of the outer cover  40  are inserted through the inner side of the compression coil spring  52 . The compression coil spring  52  urges the outer cover  40  rightward. Therefore, the outer cover  40  is retained at the first position by the urging force of the compression coil spring  52 . If the outer cover  40  is moved leftward in opposition to the urging force of the compression coil spring  52 , the outer cover  40  may move as far as the second position, as described above. 
         [0054]    Next, operation of the present exemplary embodiment is described. 
         [0055]    When a luggage compartment of a vehicle is to be covered using the tonneau cover apparatus  10 , the tonneau cover apparatus  10  is mounted at the vehicle upper side of the luggage compartment. At this time, each outer cover  40  of the tonneau cover apparatus  10  is to be anchored in, for example, a recess formed in a side wall of the luggage compartment of the vehicle. 
         [0056]    When the outer cover  40  of the tonneau cover apparatus  10  is being anchored in the recess, the outer cover  40  is gripped, and the outer cover  40  is moved from the first position to the second position (in the inward direction of the winding shaft  32  axial direction) in opposition to the urging force of the compression coil spring  52 . At this time, the hook  48  and the hook  50  of the boss  46  of the outer cover  40  are moved in the long hole  26  and the long hole  30 , respectively, of the tube portion  22 . As a result, the length direction length of the tonneau cover apparatus  10  is shortened. In this state, a position of the outer cover  40  is matched with a position of the recess and, when the outer cover  40  is released, the outer cover  40  is moved rightward from the second position (outward in the winding shaft  32  axial direction) by the urging force of the compression coil spring  52 . As a result, the tonneau cover apparatus  10  is mounted to the vehicle. 
         [0057]    In this state, when the other end of the tonneau cover is pulled, the tonneau cover is pulled out through the slit  14  of the case  12 . The other end of the pulled out tonneau cover is anchored at the vehicle. Thus, the tonneau cover covers the luggage compartment of the vehicle. 
         [0058]    Then, when the tonneau cover apparatus  10  is to be removed from the vehicle, each outer cover  40  is gripped, and the outer cover  40  is moved leftward to the second position in opposition to the urging force of the compression coil spring  52 . Thus, the length direction length of the tonneau cover apparatus  10  is shortened, and the anchoring between the outer cover  40  and the recess of the vehicle may be released. 
         [0059]    Subsequently, when the outer cover  40  is released, the outer cover  40  is moved to the first position by the urging force of the compression coil spring  52 . At this time, the hook  48  and the hook  50  of the boss  46  of the outer cover  40  are abutted against the abutting face  26 A of the long hole  26  and the abutting face  30 A of the long hole  30 , respectively, of the tube portion  22 . Consequently, rightward movement of the outer cover  40  is blocked and detachment of the outer cover  40  from the case  12  is prevented. 
         [0060]    Herein, the tube portion  22  (the abutting face  26 A and the abutting face  30 A) and the boss  46  (the hook  48  and the hook  50 ) are disposed at the inner side of the outer cover  40  relative to the peripheral wall  44  and floor wall  42  of the outer cover  40 . Therefore, the boss  46  (the hook  48  and the hook  50 ) and the tube portion  22  (the abutting face  26 A and the abutting face  30 A) are not exposed to the exterior by the peripheral wall  44  and the floor wall  42 . Thus, detachment of the outer cover  40  from the case  12  may be prevented while effects on the external appearance of the tonneau cover apparatus  10  are restrained. 
         [0061]    The tube portion  22  of the inner cover  16  is formed substantially in the shape of a cross-shaped tube and the boss  46  of the outer cover  40  is formed substantially in the shape of a cross-shaped tube, the long hole  26  and the long hole  30  are formed in the tube portion  22  of the inner cover  16  and the hook  48  and the hook  50  are formed at the boss  46  of the outer cover  40 , and the boss  46  of the outer cover  40  is inserted inside the tube portion  22  and the boss  46  is made slidable in the left-right direction at the inner periphery portion of the tube portion  22 . Therefore, the tube portion  22  may guide the boss  46  when the outer cover  40  moves from the first position toward the second position, and the boss  46  and the tube portion  22  prevent detachment of the outer cover  40  from the case  12 . 
         [0062]    The long hole  26  and the long hole  30  are formed to penetrate through the tube portion  22  in rectangular shapes, and the long hole  26  and the long hole  30  are arranged with the length directions thereof in the axial direction of the winding shaft  32 . The right end face of the inner periphery face of the long hole  26  serves as the abutting face  26 A and the right end face of the inner periphery face of the long hole  30  serves as the abutting face  30 A, and the hook  48  and the hook  50  are abutted against the abutting face  26 A and the abutting face  30 A, respectively, at the first position. Therefore, detachment of the outer cover  40  from the case  12  may be prevented with a simple structure. 
         [0063]    The tube portion  22  of the inner cover  16  and the boss  46  of the outer cover  40  are disposed at the central portion of the outer cover  40 . Therefore, when the outer cover  40  is being moved from the first position toward the second position, the outer cover  40  may be moved along the axial direction of the tube portion  22  and the boss  46  easily. Therefore, the outer cover  40  may be moved from the first position to the second position smoothly. 
         [0064]    The compression coil spring  52  spans between the floor wall of the inner cover  16  and the floor wall  42  of the outer cover  40 , and the tube portion  22  and the boss  46  are inserted into the inside of the compression coil spring  52 . Therefore, the position of the compression coil spring  52  may be specified by the tube portion  22  and the boss  46 , and slanting of the compression coil spring  52  may be suppressed. As a result, mounting characteristics when the compression coil spring  52  is being mounted may be improved. In addition, because the urging force of the compression coil spring  52  acts along the axial direction of the tube portion  22  and the boss  46 , the outer cover  40  may be moved from the first position to the second position even more smoothly. 
         [0065]    In the present exemplary embodiment, the tube portion  22  is provided at the inner cover  16  and the boss  46  is provided at the outer cover  40 . However, the boss  46  may be provided at the inner cover  16  and the tube portion  22  provided at the outer cover  40  instead. In this case, the left end face of the inner periphery face of the long hole  26  serves as the abutting face  26 A and the left end face of the inner periphery face of the long hole  30  serves as the abutting face  30 A. 
         [0066]    In the present exemplary embodiment, the tube portion  22  of the inner cover  16  is formed substantially in the shape of a cross-shaped tube and the boss  46  of the outer cover  40  is formed substantially in the shape of a cross-shaped tube. However, shapes of the tube portion  22  and the boss  46  are not limited thus. For example, the tube portion  22  and the boss  46  may be formed in circular tube shapes, and may be formed in rectangular tube shapes. 
       Variant Example 1 
       [0067]    As illustrated in  FIG. 6 , in a variant example 1, the boss  46  is not formed at the outer cover  40 . The hook  48  is formed at an inner periphery portion of the rear side wall of the peripheral wall  44  of the outer cover  40 , and the hook  48  protrudes forward from the rear side wall of the outer cover  40 . Meanwhile, the hook  50  is formed at an inner periphery portion of the front side wall of the peripheral wall  44  of the outer cover  40 , and the hook  50  protrudes rearward from the front side wall of the outer cover  40 . 
         [0068]    The tube portion  22  is formed in a substantially rectangular tube shape at the outer periphery portion of the flange  18  of the inner cover  16 , and the tube portion  22  is protruded rearward from the flange  18 . The outer periphery portion of the tube portion  22  is slidable in the left-right direction at the inner periphery portion of the peripheral wall  44  of the outer cover  40 . The long hole  26  is formed in the rear side wall of the tube portion  22 , and the right side face of the inner periphery face of the long hole  26  serves as the abutting face  26 A. The long hole  30  is formed in the front side wall of the tube portion  22 , and the right side face of the inner periphery face of the long hole  30  serves as the abutting face  30 A. 
         [0069]    Thus, in this variant example 1 too, the hook  48 , the hook  50  and the tube portion  22  are disposed at the inner side of the outer cover  40  relative to the peripheral wall  44  and floor wall  42  of the outer cover  40 , and the hook  48 , the hook  50  and the tube portion  22  are not exposed to the exterior by the peripheral wall  44  and the floor wall  42 . Thus, detachment of the outer cover  40  from the case  12  may be prevented while effects on the external appearance of the tonneau cover apparatus  10  are restrained. 
       Variant Example 2 
       [0070]    As illustrated in  FIG. 7 , in a variant example 2, the boss  46  is not formed at the outer cover  40 . A protrusion portion  60 , with a triangular shape in cross-section, is formed at an inner periphery portion of the rear side wall of the peripheral wall  44  of the outer cover  40 . The protrusion portion  60  protrudes forward from the rear side wall of the peripheral wall  44 , and a right side face of the protrusion portion  60  serves as the abutting face  26 A. A protrusion portion  62 , with a triangular shape in cross-section, is formed at an inner periphery portion of the front side wall of the peripheral wall  44  of the outer cover  40 . The protrusion portion  62  protrudes rearward from the front side wall of the peripheral wall  44 , and a right side face of the protrusion portion  62  serves as the abutting face  30 A. 
         [0071]    The tube portion  22  is formed at the inner cover  16 . The outer cover  40  is formed, substantially in a rectangular tube shape, at the outer periphery portion of the flange  18  of the inner cover  16 , and the boss  46  is protruded rightward from the flange  18 . The hook  48  is formed at an outer periphery portion of the rear side wall of the boss  46 , and the hook  48  is protruded rearward from the boss  46 . The hook  50  is formed at an outer periphery portion of the front side wall of the boss  46 , and the hook  50  is protruded forward from the boss  46 . 
         [0072]    Thus, in this variant example 2 too, the protrusion portion  60 , the protrusion portion  62  and the boss  46  are disposed at the inner side of the outer cover  40  relative to the peripheral wall  44  and floor wall  42  of the outer cover  40 , and the protrusion portion  60 , the protrusion portion  62  and the boss  46  are not exposed to the exterior by the peripheral wall  44  and the floor wall  42 . Thus, detachment of the outer cover  40  from the case  12  may be prevented while effects on the external appearance of the tonneau cover apparatus  10  are restrained. 
         [0073]    In the present exemplary embodiment and variant example 1 and variant example 2, the outer covers  40  are movably retained at the right end portion (one end portion) and the left end portion (other end portion) of the tonneau cover apparatus  10  (the case  12 ) to be movable from the respective first positions thereof to the second positions (inward in the axial direction of the winding shaft  32 ). However, the outer cover  40  may be retained to be movable from the first position to the second position at only one or other of the right end portion and the left end portion of the tonneau cover apparatus  10 . In this case, the outer cover  40  at the other of the right end portion and the left end portion may be constituted to be immovable by the compression coil spring  52  not being provided and the inner cover  16  and outer cover  40  being formed as an integral component.