Patent Publication Number: US-2023150410-A1

Title: Conveyance seat and conveyance seat manufacturing method

Description:
TECHNICAL FIELD 
     The present invention relates to a conveyance seat and a method for manufacturing the conveyance seat. More particularly, the present invention relates to a conveyance seat having a pocket on the rear surface of a seat back and a method for manufacturing the conveyance seat. 
     BACKGROUND ART 
     Known in the related art is a conveyance seat having a seat back configured by placing a cushion material on a back frame serving as a skeleton and covering the cushion material with a skin material. The conveyance seat may be formed with a bag-shaped pocket attached by sewing to the outer surface of a back side skin material positioned on the rear surface of the seat back and capable of storing a small article or the like (see, for example, Patent Literature 1 and Patent Literature 2). 
     The vehicle seat disclosed in Patent Literature 1 includes a pocket attached by sewing to the rear surface of a seat back. The pocket is sized to reach the right and left end portions of the seat back in the seat width direction, and the opening portion of the pocket is also elongated so as to reach the right and left end portions of the seat back. 
     Likewise, the conveyance seat described in Patent Literature 2 has a pocket attached by sewing to the rear surface of a seat back. The pocket is disposed at the middle part of the seat back in the seat width direction and is somewhat narrower than the seat back. In addition, the opening portion of the pocket also has a length corresponding to the size of the pocket. 
     CITATION LIST 
     Patent Literature 
     PATENT LITERATURE 1: JP H10-327978 
     PATENT LITERATURE 2: JP 2010-105485 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     By the way, in the case of the pocket shape of the vehicle seat as in Patent Literature 1, although the capacity can be relatively large, the opening portion of the pocket extends to the right and left end portions of the seat back, and thus the opening portion is not closed with ease, the appearance of the vehicle seat is not satisfactory, and the design may be impaired. 
     In addition, in the case of the pocket shape of the conveyance seat as in Patent Literature 2, the length of the opening portion of the pocket corresponds to the size of the pocket and, although the appearance of the conveyance seat is not impaired, the capacity of the pocket may decrease to cause a decline in functionality. 
     Accordingly, there has been a demand for a technique enabling pocket capacity maximization without impairing the appearance of a conveyance seat during pocket formation on the rear surface of the conveyance seat. 
     Further, there has been a demand for a technique with which a pocket on the rear surface of a conveyance seat can be formed in a relatively simple manner. 
     The present invention has been made in view of the above problems, and an object of the present invention is to provide a conveyance seat and a method for manufacturing the conveyance seat with which the capacity of a pocket can be ensured without impairing the appearance of the conveyance seat in forming the pocket on the rear surface of the conveyance seat. 
     In addition, another object of the present invention is to provide a conveyance seat and a method for manufacturing the conveyance seat enabling simple pocket formation on the rear surface thereof. 
     Solution to Problem 
     The above object is achieved by means of the conveyance seat of the present invention, which is a conveyance seat provided with a pocket on a rear surface of a seat back, in which the seat back has a skin material serving as a covering material for the seat back, the pocket has: a sheet-shaped pocket forming member overlapping an outer surface of a back side skin material positioned on the rear surface of the seat back; and a pocket sewn portion for attaching the pocket forming member to the back side skin material in an overlapping state, the pocket sewn portion has: right and left first sewn portions provided in order to form an opening portion of the pocket in an upper end portion of the pocket forming member, formed at positions sandwiching the opening portion in a seat width direction, and each extending in the seat width direction; right and left second sewn portions formed at positions sandwiching the opening portion in the seat width direction, respectively connected to the right and left first sewn portions, and extending in a direction intersecting the right and left first sewn portions; right and left third sewn portions respectively formed in both end portions of the pocket forming member in the seat width direction in order to form right and left outer edge portions of the pocket and extending in an up to down direction; and a fourth sewn portion formed in a lower end portion of the pocket forming member in order to form a lower edge portion of the pocket and extending in the seat width direction, and the right and left second sewn portions are disposed inside the right and left third sewn portions in the seat width direction. 
     With the above configuration, it is possible to realize a conveyance seat with which the capacity of a pocket can be ensured without impairing the appearance of the conveyance seat. 
     Specifically, the pocket sewn portion has: right and left first sewn portions provided in order to form an opening portion of the pocket in an upper end portion of the pocket forming member, formed at positions sandwiching the opening portion in a seat width direction, and each extending in the seat width direction; and right and left second sewn portions formed at positions sandwiching the opening portion in the seat width direction, respectively connected to the right and left first sewn portions, and extending in a direction intersecting the right and left first sewn portions. In other words, the opening portion of the pocket is formed at the middle part of the seat back in the seat width direction and does not have a length of reaching the right and left end portions of the seat back. Accordingly, with the shape of the opening portion, the appearance of the conveyance seat is not impaired. 
     In addition, the right and left second sewn portions at the positions sandwiching the opening portion of the pocket are disposed inside the right and left third sewn portions forming the right and left outer edge portions of the pocket in the seat width direction. In other words, in this configuration, the opening portion of the pocket is narrow and the accommodating portion of the pocket is wide. 
     Accordingly, the capacity of the pocket can be ensured (increased) with the shape of the opening portion. 
     At this time, in a state where a surface of the pocket forming member partially overlaps the outer surface of the back side skin material, the right and left first sewn portions and the right and left second sewn portions may be formed at the overlapping part, and, in a state where a part other than the overlapping part is folded back via a fold provided on the pocket forming member, the right and left third sewn portions and the fourth sewn portion may be formed at the folded part. 
     With the above configuration, when the pocket is formed on the rear surface of the conveyance seat, the sewing line can be made as inconspicuous as possible and design can be ensured. In addition, the pocket can be manufactured by a relatively simple manufacturing method. 
     At this time, the pocket may have a plate-shaped plate member attached to the pocket forming member at a position corresponding to the opening portion and extending in the seat width direction along the opening portion, and the plate member may be disposed between the right and left second sewn portions in the seat width direction and may be disposed at a position not intersecting the right and left second sewn portions. 
     With the above configuration, the strength of and around the opening portion of the pocket can be increased and the functionality of the pocket can be increased. 
     In addition, the pocket is easily formed by having the plate member. 
     At this time, the pocket may have a plate sewn portion for attaching the plate member to the pocket forming member, and the plate sewn portion may extend in the seat width direction along the extension direction of the plate member and may intersect the right and left second sewn portions. 
     With the above configuration, the sewing strength around the opening portion of the pocket can be increased. In other words, the sewing strength of the first sewn portion and the second sewn portion can be increased. 
     At this time, the right and left second sewn portions may respectively extend in a direction substantially orthogonal to the right and left first direction portions. 
     With the above configuration, interference with the second sewn portion can be avoided as much as possible when an occupant uses the pocket (puts his or her hand into the pocket). 
     At this time, the second sewn portion may have: a first extending portion extending in a direction intersecting the first sewn portion; and a second extending portion connected to the first extending portion and extending outward in the seat width direction from the first extending portion in a direction intersecting the first extending portion. 
     In addition, the second extending portion of the second sewn portion may extend in a direction inclined with respect to the first sewn portion. 
     In addition, the second extending portion of the second sewn portion may extend outward in the seat width direction away from the first sewn portion. 
     With the above configuration, the sewing strength of and around the opening portion of the pocket (right and left end portions of the opening portion) can be further increased. 
     In addition, with the above configuration, interference with the second sewn portion can be avoided when an occupant puts a small article into the pocket or takes a small article out of the pocket. 
     In addition, the above object is achieved by means of a method for manufacturing a conveyance seat provided with a pocket on a rear surface of a seat back, the conveyance seat manufacturing method including a step of manufacturing the pocket, in which, in the step of manufacturing the pocket, a sheet-shaped pocket forming member is caused to overlap an outer surface of a back side skin material disposed on the rear surface of the seat back as a part of a skin material serving as a covering material for the seat back, and the pocket forming member is attached to the back side skin material by a pocket sewn portion in an overlapping state, and, when the pocket forming member is attached, the pocket forming member is attached by: right and left first sewn portions provided in order to form an opening portion of the pocket in an upper end portion of the pocket forming member, formed at positions sandwiching the opening portion in a seat width direction, and each extending in the seat width direction; right and left second sewn portions formed at positions sandwiching the opening portion in the seat width direction, respectively connected to the right and left first sewn portions, and extending in a direction intersecting the right and left first sewn portions; right and left third sewn portions respectively formed in both end portions of the pocket forming member in the seat width direction in order to form right and left outer edge portions of the pocket and extending in an up to down direction such that the right and left second sewn portions are disposed inside in the seat width direction; and a fourth sewn portion formed in a lower end portion of the pocket forming member in order to form a lower edge portion of the pocket and extending in the seat width direction. 
     At this time, when the pocket forming member is attached, in a state where a surface of the pocket forming member partially overlaps the outer surface of the back side skin material, the overlapping part may be attached by the right and left first sewn portions and the right and left second sewn portions, and, in a state where a part other than the overlapping part is folded back via a fold provided on the pocket forming member, the folded part may be further attached by the right and left third sewn portions and the fourth sewn portion. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to realize a conveyance seat with which the capacity of a pocket can be ensured without impairing the appearance of the conveyance seat. 
     Specifically, the opening portion of the pocket is formed at the middle part of the seat back in the seat width direction and does not have a length of reaching the right and left end portions of the seat back. Accordingly, with the shape of the opening portion, the appearance of the conveyance seat is not impaired. 
     In addition, in this configuration, the opening portion of the pocket is narrow and the accommodating portion of the pocket is wide. Accordingly, the capacity of the pocket can be ensured (increased) with the shape of the opening portion. 
     In addition, according to the present invention, the sewing line can be made as inconspicuous as possible and design can be ensured. In addition, the pocket can be manufactured by a relatively simple manufacturing method. 
     In addition, according to the present invention, the strength of and around the opening portion of the pocket can be increased and the functionality of the pocket can be increased. In addition, the pocket is easily formed. 
     In addition, according to the present invention, the sewing strength around the opening portion of the pocket can be increased. 
     In addition, according to the present invention, interference with the second sewn portion can be avoided when an occupant uses the pocket (puts his or her hand into the pocket). 
     In addition, according to the present invention, the sewing strength of and around the opening portion of the pocket (right and left end portions of the opening portion) can be further increased. In addition, interference with the second sewn portion can be avoided when an occupant puts a small article into the pocket or takes a small article out of the pocket. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is an external perspective view of a conveyance seat according to the present embodiment. 
         FIG.  2    is a perspective view of the conveyance seat viewed from a rear surface side. 
         FIG.  3 A  is a diagram illustrating a state where a plate member is sewn to a pocket forming member. 
         FIG.  3 B  is a diagram illustrating a state where the pocket forming member of  FIG.  3 A  overlaps and is sewn to a back side skin material. 
         FIG.  3 C  is a diagram illustrating a folded state of the pocket forming member of  FIG.  3 B . 
         FIG.  3 D  is a diagram illustrating a state where the pocket forming member is sewn from the state of  FIG.  3 C . 
         FIG.  4 A  is a diagram illustrating a state where a plate member is sewn to a pocket forming member of a second embodiment. 
         FIG.  4 B  is a diagram illustrating a state where the pocket forming member of  FIG.  4 A  overlaps and is sewn to a back side skin material. 
         FIG.  4 C  is a diagram illustrating a folded state of the pocket forming member of  FIG.  4 B . 
         FIG.  4 D  is a diagram illustrating a state where the pocket forming member is sewn from the state of  FIG.  4 C . 
         FIG.  5    is a top view illustrating a seat heater (middle and side heaters). 
         FIG.  6 A  is a VI-VI cross-sectional view of the seat heater. 
         FIG.  6 B  is a VI-VI cross-sectional view of a seat heater of Modification Example 1. 
         FIG.  7    is a top view of the middle heater, illustrating that the middle heater can be partially folded. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments according to the present invention will be described below with reference to  FIGS.  1  to  7   . 
     The present embodiment relates to an invention of a conveyance seat provided with a pocket on a rear surface of a seat back, in which the pocket has: a sheet-shaped pocket forming member overlapping an outer surface of a back side skin material positioned on the rear surface of the seat back; and a pocket sewn portion, the pocket sewn portion has: right and left first sewn portions provided in order to form an opening portion of the pocket in an upper end portion of the pocket forming member and formed at positions sandwiching the opening portion in a seat width direction; right and left second sewn portions formed at positions sandwiching the opening portion and extending in a direction intersecting the right and left first sewn portions; right and left third sewn portions forming right and left outer edge portions of the pocket; and a fourth sewn portion forming a lower edge portion of the pocket, and the right and left second sewn portions are disposed inside the right and left third sewn portions. 
     It should be noted that the side on which an occupant sits with respect to the seat back of the conveyance seat is the front side of the seat. 
     As illustrated in  FIG.  1   , a conveyance seat S of the present embodiment is a vehicle seat and is configured mainly from a seat main body including a seat back  1 , a seat cushion  2 , and a headrest  3 , a pocket  30  attached to the rear surface of the seat back  1 , and a sheet-shaped seat heater  40  attached in the seat main body. 
     As illustrated in  FIGS.  1  and  2   , the seat back  1  is a backrest portion supporting a seated occupant&#39;s back from behind and is configured by placing a cushion material  10  on a back frame (not illustrated) serving as a skeleton and covering the cushion material  10  with a skin material  20 . 
     The seat back  1  is configured from a middle portion  1 A at the middle part in the seat width direction and right and left side portions  1 B (side bolster portions) outside the middle portion  1 A in the seat width direction. 
     Right and left skin pull-in grooves  10   a  extending in the up to down direction are formed on the surface of the cushion material  10  so as to divide the middle portion  1 A and the right and left side portions  1 B. 
     The bag-shaped pocket  30  capable of storing a small article or the like is attached by sewing to the rear surface of the seat back  1 . 
     As illustrated in  FIG.  1   , the seat cushion  2  is a seating portion supporting the seated occupant from below and is configured by placing a cushion material  2   a  on a cushion frame (not illustrated) serving as a skeleton and covering the cushion material  2   a  with a skin material  2   b.    
     Similarly, the seat cushion  2  is configured from a middle portion  2 A at the middle part in the seat width direction and right and left side portions  2 B (side bolster portions) outside the middle portion  2 A in the seat width direction. 
     Right and left skin pull-in grooves  2   aa  extending in the up to down direction are formed on the surface of the cushion material  2   a  so as to divide the middle portion  2 A and the right and left side portions  2 B. 
     The headrest  3  is a head portion supporting the occupant&#39;s head from behind and is configured by placing a cushion material  3   a  on a headrest pillar (not illustrated) serving as a core material and covering the cushion material  3   a  with a skin material  3   b.    
     The cushion material  10  is a pad member made of foamed urethane or the like. 
     The skin material  20  is made of a resin material (for example, TPO), fabric (for example, PET material), genuine leather, or the like and is formed in a shape in which the cushion material  10  can be covered from the outside. 
     In the above configuration, as illustrated in  FIG.  1   , the seat heater  40  is attached between the cushion material  10  and the skin material  20  in the seat back  1 . 
     It should be noted that the seat heater  40  is also attached between the cushion material  2   a  and the skin material  2   b  in the seat cushion  2 . 
     As illustrated in  FIGS.  2  and  3 A to  3 D , the pocket  30  is a bag-shaped pocket (back pocket) formed on the lower part of the rear surface of the seat back  1  and has an opening portion  30   a  in the upper end portion thereof. 
     The pocket  30  has a sheet-shaped pocket forming sheet  31  (pocket forming member) overlapping the outer surface of a back side skin material  20   a  positioned on the rear surface of the seat back  1  and a plate-shaped plate member  32  attached to the pocket forming sheet  31  at a position corresponding to the opening portion  30   a.    
     In addition, the pocket  30  has a plate sewn portion  33  for attaching the plate member  32  to the pocket forming sheet  31  as illustrated in  FIG.  3 A  and a pocket sewn portion  34  for attaching the pocket forming sheet  31  to the back side skin material  20   a  in an overlapping state as illustrated in  FIGS.  3 B to  3 D . 
     The pocket forming sheet  31  is formed of a sheet-shaped material similarly to the skin material  20  and is a substantially rectangular sheet for forming the pocket  30 . 
     As illustrated in  FIG.  3 A , the plate-shaped plate member  32  elongated in the seat width direction is attached to one end portion of the back surface of the pocket forming sheet  31  in the up to down direction. 
     The plate member  32  is a reinforcing member increasing the strength of the opening portion  30   a  of the pocket  30  and is formed of a resin material having predetermined hardness and elasticity. 
     As illustrated in  FIG.  3 D , the length of the plate member  32  corresponds to the length of the opening portion  30   a  of the pocket  30 . 
     The plate sewn portion  33  extends along the extension direction of the plate member  32  and straddles the plate member  32  in the seat width direction to reach the right and left end portions of the pocket forming sheet  31 . 
     It should be noted that the plate sewn portion  33  and the pocket sewn portion  34  are sewn parts formed by, for example, sewing work using a known automatic sewing machine (XY automatic sewing machine). 
     As illustrated in  FIGS.  3 B and  3 D , the pocket sewn portion  34  has right and left first sewn portions  34   a  and right and left second sewn portions  34   b  forming the upper edge portion of the pocket  30  and forming (partitioning) the opening portion of the pocket  30 , right and left third sewn portions  34   c  forming the right and left outer edge portions of the pocket  30 , and a fourth sewn portion  34   d  forming the lower edge portion of the pocket  30 . 
     As illustrated in  FIG.  3 B , in a state where the surface of the pocket forming sheet  31  partially overlaps the outer surface of the back side skin material  20   a,  the right and left first sewn portions  34   a  and the right and left second sewn portions  34   b  are formed at the overlapping part. 
     Meanwhile, as illustrated in  FIGS.  3 B to  3 D , in a state where the upper part other than the overlapping part (part different from the overlapping part) is folded back via a fold  35  provided on the pocket forming sheet  31 , the right and left third sewn portions  34   c  and the fourth sewn portion  34   d are formed at the folded part.    
     As illustrated in  FIG.  3 B , the right and left first sewn portions  34   a  are formed at positions sandwiching the opening portion  30   a  in the seat width direction and each of the right and left first sewn portions  34   a  extends in the seat width direction. 
     More specifically, the right and left first sewn portions  34   a  are disposed at the height position overlapping the plate member  32  in the up to down direction and extend substantially linearly from the right and left end portions of the pocket forming sheet  31  to positions close to the plate member  32 . 
     It should be noted that as illustrated in  FIG.  3 D , in the present embodiment, the first sewn portions  34   a  and the fold  35  are disposed at overlapping positions. 
     The right and left second sewn portions  34   b  are formed continuously from the extending end portions of the right and left first sewn portions  34   a,  respectively. The right and left second sewn portions  34   b  are formed at positions sandwiching the opening portion  30   a  in the seat width direction. The right and left second sewn portions  34   b  extend in a direction intersecting the right and left first sewn portions  34   a.    
     More specifically, the right and left second sewn portions  34   b  extend in a direction substantially orthogonal to the first sewn portions  34   a.  Specifically, the right and left second sewn portions  34   b  extend downward from the extending end portions of the first sewn portions  34   a  and reach one end portion of the pocket forming sheet  31  in the up to down direction. 
     It should be noted that the right and left first sewn portions  34   a  and the right and left second sewn portions  34   b  are disposed at positions that do not intersect the plate member  32 . 
     As illustrated in  FIG.  3 D , the right and left third sewn portions  34   c  are respectively formed in the right and left end portions of the pocket forming sheet  31  in the seat width direction and extend elongatedly in the up to down direction. 
     It should be noted that the upper end portions of the right and left third sewn portions  34   c  extend to positions somewhat protruding beyond the upper end portion of the pocket forming sheet  31 . 
     The fourth sewn portion  34   d  is formed in the lower end portion of the pocket forming sheet  31 , extends so as to be elongated in the seat width direction, and connects the right and left third sewn portions  34   c.    
     Specifically, in attaching the pocket  30  in the above configuration, sewing work is started from the upper end portion of the third sewn portion  34   c  on the left side, the third sewn portion  34   c  on the left side, the fourth sewn portion  34   d,  and the third sewn portion  34   c  on the right side are sewn continuously, and the sewing work is completed when the upper end portion of the third sewn portion  34   c  on the right side is reached. It should be noted that the sewing work may be started from the upper end portion of the third sewn portion  34   c  on the right side conversely. 
     As illustrated in  FIGS.  2  and  3 D , with the above configuration, the opening portion  30   a  of the pocket  30  is formed at the middle part of the seat back  1  in the seat width direction and does not have a length of reaching the right and left end portions of the seat back  1 . Accordingly, with the shape of the opening portion  30   a,  the closing of the opening portion  30   a  is improved and the appearance of the conveyance seat S is not impaired. 
     In addition, in the above configuration, as illustrated in  FIG.  3 D , the right and left second sewn portions  34   b  are disposed inside the right and left third sewn portions  34   c  in the seat width direction. 
     In other words, in this configuration, the opening portion  30   a  of the pocket  30  is narrow in the seat width direction and the accommodating portion of the pocket  30  is wide. 
     Accordingly, the capacity of the pocket  30  can be increased with the shape of the opening portion  30   a.    
     In addition, in the above configuration, as illustrated in  FIG.  3 D , the plate sewn portion  33  extends in the seat width direction along the extension direction of the plate member  32  and intersects the right and left second sewn portions  34   b.    
     Accordingly, the sewing strength around the opening portion  30   a  of the pocket  30  can be increased. In other words, the sewing strength of the first sewn portions  34   a  and the second sewn portions  34   b  can be increased. 
     &lt;Conveyance Seat Manufacturing Method&gt; 
     Next, among the steps of a method for manufacturing the conveyance seat S, a step of manufacturing the pocket  30  will be described with reference to  FIGS.  3 A to  3 D . 
     It should be noted that the method for manufacturing the conveyance seat S includes, for example, a step of manufacturing the seat main body and the step of manufacturing the pocket  30  on the rear surface of the seat main body (seat back  1 ). 
     In the step of manufacturing the pocket  30 , first, “first work” is performed to overlap the pocket forming sheet  31  on the outer surface of the back side skin material  20   a  of the skin material  20  of the seat back  1  disposed on the rear surface of the seat back  1 . After that, “second work” is performed to attach the pocket forming sheet to the back side skin material  20   a  with the pocket sewn portion  34  in an overlapping state. 
     More specifically, in the “second work”, the pocket forming sheet  31  is attached by the right and left first sewn portions  34   a  and the right and left second sewn portions  34   b  provided for forming the opening portion  30   a  of the pocket  30  in the upper end portion of the pocket forming sheet  31  and formed at positions sandwiching the opening portion  30   a  in the seat width direction, the right and left third sewn portions  34   c  respectively formed in the right and left end portions of the pocket forming sheet  31  for forming the right and left outer edge portions of the pocket  30 , and the fourth sewn portion  34   d  formed in the lower end portion of the pocket forming sheet  31  for forming the lower edge portion of the pocket  30 . 
     More specifically, in the “second work”, in a state where the surface of the pocket forming sheet  31  partially overlaps the outer surface of the back side skin material  20   a,  the overlapping part is attached by the right and left first sewn portions  34   a  and the right and left second sewn portions  34   b.  Then, in a state where the part other than the overlapping part is folded back via the fold  35  provided on the pocket forming sheet  31 , the folded part is further attached by the right and left third sewn portions  34   c  and the fourth sewn portion  34   d.    
     According to the manufacturing method described above, it is possible to realize a conveyance seat manufacturing method by which the capacity of a pocket can be ensured without impairing the appearance of a conveyance seat. 
     In addition, it is possible to realize a conveyance seat manufacturing method by which the pocket can be simply formed. 
     &lt;Second Embodiment of Pocket&gt; 
     Next, a pocket  130  of a second embodiment will be described with reference to  FIGS.  4 A to  4 D . 
     It should be noted that the description of the content that is common to the pocket  30  and the pocket  130  will be omitted. 
     The pocket  130  differs from the pocket  30  mainly in the configuration of a pocket sewn portion  134 . 
     The pocket  130  has an opening portion  130   a  in the upper end portion thereof and is configured mainly from a pocket forming sheet  131 , a plate-shaped plate member  132 , a plate sewn portion  133 , and the pocket sewn portion  134 . 
     The pocket forming sheet  131  is a substantially rectangular sheet, and right and left sheet pieces  131   a  are formed in the corner portions of the right and left end portions of the pocket forming sheet  131  so as to partially protrude from the main body of the pocket forming sheet  131 . 
     As illustrated in  FIG.  3 A , the plate-shaped plate member  132  elongated in the seat width direction is attached to one end portion of the back surface of the pocket forming sheet  131  in the up to down direction. 
     The pocket sewn portion  134  has right and left first sewn portions  134   a  and right and left second sewn portions  134   b  forming the opening portion  130   a  of the pocket, right and left third sewn portions  134   c  forming the right and left outer edge portions of the pocket  130 , and a fourth sewn portion  134   d forming the lower edge portion of the pocket    
     The second sewn portion  134   b  has a first extending portion  134   ba  extending in a direction orthogonal to the first sewn portion  134   a  (downward) and a second extending portion  134   bb  continuous from the extending end portion of the first extending portion  134   ba  and extending outward in the seat width direction while being inclined downward. 
     The second extending portion  134   bb  extends in a direction inclined with respect to the first sewn portion  134   a.  Specifically, the second extending portion  134   bb  extends away from the first sewn portion  134   a  and outward in the seat width direction while being inclined downward. 
     It should be noted that the second extending portion  134   bb  is formed so as to extend along the outer edge of the sheet piece  131   a  of the pocket forming sheet  131 . 
     With the above configuration, the sewing strength of and around the opening portion  130   a  of the pocket  130  can be further increased. In addition, interference with the first sewn portion  134   a  and the second sewn portion  134   b  can be avoided when an occupant puts a small article into the pocket  130  or takes a small article out of the pocket  130 . 
     In the second embodiment as well, in forming the pocket on the rear surface of the conveyance seat, the capacity of the pocket can be ensured without impairing the appearance of the conveyance seat. In addition, the pocket can be simply formed. 
     &lt;Details of Seat Heater&gt; 
     Next, the seat heater  40  will be described in detail with reference to  FIGS.  5  to  7   . 
     The main feature of the seat heater  40  of the present embodiment is that the seat heater  40  is attached to the skin material  20  integrated with a cotton-shaped wadding material  21  by sewing only the wadding material  21  by blind stitching such that the sewing line is not exposed. 
     It should be noted that as for the related art, a sheet-shaped seat heater attached by sewing to a skin material with a cotton-shaped wadding material is known as in International Publication No. WO 2014/091710. The seat heater is sewn to the skin material, and the sewing line is exposed on the outer surface of the skin material. Accordingly, the appearance of a vehicle seat may be affected and the design may be impaired. Alternatively, in order to make the sewing line as inconspicuous as possible, the sewing line and the formation line of a skin pull-in groove (joint) are aligned as a response. 
     An object in this regard is to provide a conveyance seat with a sheet-shaped seat heater with which the seat heater can be suitably attached to a skin material without impairing the appearance of the conveyance seat. 
       FIG.  5    is a diagram illustrating a state where the seat heater  40  is attached by blind stitching to the back surface of the skin material  20  with the wadding material  21 . 
     The cotton-shaped wadding material  21  (slab material) is attached with an adhesive to substantially the entire back surface of the skin material  20 . It should be noted that the wadding material  21  may be attached by, for example, sewing without being limited to the adhesive. 
     As illustrated in  FIGS.  1  and  5   , the seat heater  40  is a sheet-shaped heating element (planar heating element) that warms the seat main body. As illustrated in  FIG.  1   , the seat heater  40  is attached in the seat back  1  and disposed between the cushion material  10  and the skin material  20 . 
     It should be noted that the seat heater  40  is also attached in the seat cushion  2 . 
     The seat heater  40  attached to the seat back  1  will be described below. 
     The seat heater  40  is configured mainly from a rectangular middle heater  40   a  disposed in the middle portion  1 A of the seat back  1  and side heaters  40   b  and  40   c  disposed in the left and right side portions  1 B. 
     The seat heater  40  is configured mainly from a sheet-shaped sheet base material  41 , electric wires  42  respectively attached on the sheet base material  41  and connected to a power source (not illustrated), a heater wire  43  connected to the electric wires  42 , a temperature measurement sensor (thermistor, not illustrated) connected to the electric wires  42 , and a temperature adjustment device (thermostat, not illustrated) connected to the electric wires  42 . 
     The electric wires  42 , the heater wire  43 , the temperature measurement sensor, and the temperature adjustment device are densely disposed at the lower end part of the seat heater  40 , and a cover member  44  is attached to cover these components. 
     The electric wires  42  supply electricity from the power source (not illustrated) toward the heater wire  43 , the temperature measurement sensor, and the temperature adjustment device. A harness  42   a  is formed at one end part of the electric wires  42  by bundling the plurality of electric wires  42 . 
     The harness  42   a  is connected to the power source and a control device with one end part thereof attached on the sheet base material  41  and the other end part thereof extending so as to protrude from above the sheet base material  41 . 
     The middle heater  40   a  is attached by a heater sewn portion  45  to the back surface of the skin material  20  with the wadding material  21 . 
     As illustrated in  FIGS.  5  and  6 A , the heater sewn portion  45  is a sewn part formed by blind-stitching the middle heater  40   a  and the wadding material  21  of the skin material  20  and is formed by, for example, an automatic sewing machine (XY automatic sewing machine). 
     Specifically, the heater sewn portion  45  has a first sewn portion  45   a  where the upper end portion of the middle heater  40   a  is sewn, a second sewn portion  45   b  where the lower end portion of the middle heater  40   a  is sewn, and right and left third sewn portions  45   c  where the right and left end portions of the middle heater  40   a  are sewn. 
     It should be noted that the heater sewn portion  45  (second sewn portion  45   b  in particular) is formed at positions on the sheet base material  41  avoiding the electric wires  42  and the heater wire  43  and linearly extends at each position. 
     Similarly, the side heater  40   b  ( 40   c ) is attached by a heater sewn portion  46  (blind stitching) to the back surface of the skin material  20  with the wadding material  21 . 
     The heater sewn portion  46  has a first sewn portion  46   a  where the upper end portion of the side heater  40   b  is sewn and the second sewn portion  45   b  where the lower end portion of the side heater  40   b  is sewn. 
     It should be noted that the first sewn portion  46   a  linearly extends along the seat width direction and second sewn portions  46   b  are disposed on the right and left to avoid the electric wire  42  and the heater wire  43  and formed so as to be substantially L-shaped. 
     In the above configuration, as illustrated in  FIG.  5   , each of the first sewn portion  45   a  and the second sewn portion  45   b  of the heater sewn portion  45  extends so as to intersect the right and left third sewn portions  45   c.    
     Accordingly, the middle heater  40   a  can be firmly attached to the skin material  20  (wadding material  21 ). In particular, the sewing line is not exposed by adopting blind stitching, and thus the heater sewn portion  45  can be formed in a freer disposition than in the related art. 
     For example, as in the present embodiment, the heater sewn portion  45  can be formed inside the right and left skin pull-in grooves  10   a  in the seat width direction. 
     In addition, in the above configuration, as illustrated in  FIG.  5   , by adopting blind stitching, the side heaters  40   b  and  40   c  can be attached to the skin material  20  (wadding material  21 ) by simple sewing work using the first sewn portion  45   a  and the second sewn portion  45   b.    
     In other words, it is possible to eliminate the need to match the sewing line of the heater sewn portion  46  and the formation line of the skin pull-in groove  10   a  as in the related art. 
     In addition, in the above configuration, it is possible to adopt the attachment structure illustrated in  FIG.  6 B  as well as the attachment structure illustrated in  FIG.  6 A . 
     In  FIG.  6 B , the wadding material  21  is attached to the back surface of the skin material  20 , and a back surface material  22  larger in elastic modulus (harder) than the wadding material  21  is further attached to the back surface of the wadding material  21 . 
     The back surface material  22  is, for example, nylon half or circular knit and is attached to the back surface of the wadding material  21  with an adhesive or the like. 
     The seat heater  40  is attached to the skin material  20 , where the wadding material  21  and the back surface material  22  are integrated, so as to be sewn only to the back surface material  22  by blind stitching. 
     By performing blind stitching as described above, the seat heater  40  can be firmly attached without sewing line exposure. 
     It should be noted that the seat heater  40  may be attached so as to be sewn by blind stitching to the wadding material  21  and the back surface material  22 . 
     In addition, in the above configuration, as illustrated in  FIG.  7   , one end portion of the sheet base material  41  in the up to down direction (lower end portion) is formed so as to be narrower than the main body portion of the sheet base material  41 . 
     Then, the lower end portion of the seat heater  40  can be easily folded back using the second sewn portion  45   b  as a fold line. Accordingly, it is possible to easily perform the work of attaching each component of the seat heater  40  (electric wire  42 , heater wire  43 , temperature measurement sensor, and temperature adjustment device). In addition, by folding back the lower end portion of the seat heater  40 , it is possible to easily confirm the attachment position of each component and confirm that there is no abnormality. 
     Other Embodiments 
     In the above embodiment, as illustrated in  FIG.  3 C , the pocket  30  is formed by folding back the pocket forming sheet  31  once. However, the present invention is not particularly limited thereto and the pocket  30  does not necessarily have to be formed by folding. 
     In the above embodiment, as illustrated in  FIG.  3 A , the strength of the opening portion  30   a  of the pocket  30  is increased by attaching the plate-shaped plate member  32  to the pocket forming sheet  31 . However, the present invention is not particularly limited thereto and the plate member  32  may not be attached. 
     In the above embodiment, a conveyance seat used in an automobile has been described as a specific example. However, the present invention is not particularly limited thereto and the seat can be used as, for example, a conveyance seat for airplanes and ships as well as trains and buses. 
     In the present embodiment, the conveyance seat and the conveyance seat manufacturing method according to the present invention have been mainly described. 
     However, the above embodiment is merely an example for facilitating the understanding of the present invention and does not limit the present invention. The present invention may be modified and improved without departing from the spirit thereof, and it is a matter of course that the present invention includes equivalents thereto. 
     REFERENCE SIGNS LIST 
     S: conveyance seat 
       1 : seat back
           1 A,  2 A: middle portion     1 B,  2 B: side portion       
       2 : seat cushion
           2   a,    3   a:  cushion material
             2   aa:  skin pull-in groove         2   b,    3   b:  skin material       
       3 : headrest 
       10 : cushion material
           10   a:  skin pull-in groove       
       20 : skin material
           20   a:  back side skin material       
       21 : wadding material 
       22 : back surface material 
       30 ,  130 : pocket
           30   a,    130   a:  opening portion       
       31 ,  131 : pocket forming sheet (pocket forming member)
           131   a:  sheet piece       
       32 ,  132 : plate member 
       33 ,  133 : plate sewn portion 
       34 ,  134 : pocket sewn portion
           34   a,    134   a:  first sewn portion     34   b,    134   b:  second sewn portion
             134   ba:  first extending portion     134   bb:  second extending portion         34   c,    134   c:  third sewn portion     34   d,    134   d:  fourth sewn portion       
       35 ,  135 : fold 
       40 : seat heater
           40   a:  middle heater     40   b,    40   c:  side heater       
       41 : sheet base material 
       42 : electric wire
           42   a:  harness       
       43 : heater wire 
       44 : cover member 
       45 : heater sewn portion
           45   a:  first sewn portion     45   b:  second sewn portion     45   c:  third sewn portion       
       46 : heater sewn portion
           46   a:  first sewn portion     46   b:  second sewn portion