Abstract:
An armrest is provided having sufficient area to support arms at a comfortable position. The armrest is capable of being stowed compactly to provide aisle width sufficient for passengers&#39; walk-through, and also is capable of moved from its stowed position to its used position in a single motion. The armrest is mounted to a side portion of a seat back of a vehicle seat. The armrest includes an armrest main body and a pivot member supporting the armrest main body at the seat back side of the armrest main body. The armrest main body is pivotally attached to the side portion of the seat back via the pivot member, and the pivot member is skewed toward the vehicle rear at a substantial angle relative to a widthwise horizontal axis of the seat as it extends from a base to a distal end.

Description:
BACKGROUND 
   The present invention relates to an armrest and a vehicle seat including the same, and is particularly related to a foldable armrest which is moveable between a raised position and a forward lowered position relative to a seat back and a vehicle seat including the same. 
   An armrest for a seat of a vehicle, for example an automobile, such as a foldable armrest  110  shown in  FIG. 7 , is known. This armrest  110  can be raised at the side of the seat back  120  when unused in order not to inhibit movement of passengers. 
   To move between the front and rear seating positions in a station wagon, passengers typically walk through an aisle between adjacent seats. However, when the aisle is narrow, the armrests obstruct the aisle and inhibit passengers&#39; smooth walk-through. 
   In order to overcome this disadvantage, an armrest providing increased effective vehicle interior space by making an armrest storage compartment compact, is proposed (for example, in Japanese Patent Laid-Open No. 2001-314277 (page 7 and 8, FIGS. 2-4) (hereinafter, the &#39;277 Patent)). While the armrest of the &#39;277 Patent comfortably supports a passenger&#39;s arm in a used position, the armrest storage compartment becomes compact when the armrest is in an unused position, since the armrest can be folded toward the seat back and stowed upright at the side of the seat back. Therefore, the passengers&#39; walk-through space between adjacent seats can be cleared when this type of armrest is used in a vehicle such as a station wagon. 
   According to the prior art disclosed in the &#39;277 Patent, the armrest storage compartment becomes compact. However, this armrest requires a two-step operation of lowering the armrest to a horizontal position and rotating it before use. A need therefore exists to overcome this disadvantage. 
   SUMMARY 
   It therefore is an object of the present invention to provide an armrest having sufficient area to support arms, supporting arms at a comfortable position, and being stowed compactly to provide a sufficient aisle width for passengers&#39; walk-through, and capable of returning from a stowed position to a used position in a single motion. 
   It is another object of the present invention to provide a vehicle seat including the above armrest. 
   To achieve the objects, according to one embodiment of the present invention, an armrest mounted to a side portion of a seat back of a vehicle seat, comprising an armrest main body, and a pivot member supporting the armrest main body at the seat back side of the armrest main body, wherein the armrest main body is pivotally attached to the side portion of the seat back via the pivot member, and wherein the pivot member is skewed toward the vehicle rear at a substantial angle relative to a widthwise horizontal axis of the seat as it extends from a base to a distal end, is provided. 
   As described above, according to the armrest for various embodiments of the present invention, the armrest main body is fixed to the side portion of the seat back via the pivot member, and the pivot member is skewed toward the vehicle rear at the substantial angle relative to the widthwise horizontal axis of the seat as it extends from the base to the distal end. Thus, when rotated at the seat back side, the armrest main body is at first positioned to extend in an outwardly diverging manner from the seat back as it extends from a base to a distal end in the used position, and the distal end approaches the side portion of the seat back and the armrest is finally stowed upright in the unused position. 
   Therefore, when unused, the armrest main body is stowed closer to the seat back such that the aisle width between adjacent seats is increased and the passengers&#39; walk-through space is cleared. 
   In addition, the armrest main body does not approach a seating space too much so as to support a passenger&#39;s arm at a comfortable position. 
   More specifically, the side portion of the seat back preferably has a slant surface tilted inwardly at a substantial angle relative to a horizontal axis in a fore-aft direction of the vehicle as the slant surface extends from a front to a rear, the pivot member is preferably mounted to the slant surface so as to be positioned at a substantial angle relative to the slant surface such that an inner side of the armrest is approximately parallel to the slant surface when the armrest is raised. 
   Therefore, as when raised, the armrest main body moves toward a back side of the seat back and is positioned upright in close proximity to the slant surface, effective interior space is increased when the armrest main body is stowed. 
   In addition, by selecting the angle between the pivot member and the slant surface, the amount of travel to the used position of the armrest main body in a lateral direction and the positional relationship between the stowed armrest main body and the seat back can be adjusted. 
   Furthermore, if an angle between an axis of the pivot member and the slant surface is approximately 90 degrees, the armrest main body and the seat back can be located in close proximity to each other. 
   To achieve the objects, according to another embodiment of the present invention, an armrest mounted to a side portion of a seat back of a vehicle seat, comprising an armrest main body, and a pivot member supporting the armrest main body at the seat back side of the armrest main body, wherein the armrest main body is pivotally attached to the side portion of the seat back via the pivot member, and wherein the pivot member is skewed vertically upward at a substantial angle relative to a widthwise horizontal axis of the seat as it extends from a base to a distal end, is provided. 
   As described above, according to the armrest of various embodiments of the present invention, the armrest main body is fixed to the side portion of the seat back via the pivot member, and the pivot member is skewed vertically upward at the substantial angle relative to the widthwise horizontal axis of the seat as it extends from the base to the distal end. Thus, when rotated at the seat back side, the armrest main body is at first positioned to extend in an outwardly diverging manner from the seat back as it extends from a base to a distal end in the used position, and the distal end approaches the side portion of the seat back and the armrest is finally stowed upright in the unused position. 
   In addition, the armrest preferably comprises a surface approximately perpendicular to a vehicle floor opposite the seat back and a surface inclined toward the seat back when the armrest is raised at the side of the seat back, the surface inclined toward the seat back being on top of the surface approximately perpendicular. Therefore, when stowed at the side of the seat back, the armrest does not intrude into vehicle interior space and sufficient walk-through space is maintained. 
   Further, the side portion of the seat back is preferably tilted inwardly as it extends from a substantial center to an upper part in front view, wherein an inner side of the armrest is tilted along the side portion of the seat back. Therefore, when stowed upright at the seat back side, the armrest main body is raised to be positioned in close proximity to the slant surface of the seat back and sufficient walk-through space is maintained. 
   Furthermore, to achieve the objects, according to yet another embodiment of the present invention, a vehicle seat comprising any of the armrests prescribed above and the seat back the armrest mounted thereto, is provided. 
   According to the armrest and vehicle seat including the same of various embodiments of the present invention, with a simple structure that the pivot member holding the armrest main body at the seat back side is tilted, when stowed upright at the side of the seat back the armrest main body is positioned closer to the seat back. As a result, an aisle width between adjacent seats is increased and sufficient walk-through space is maintained in the vehicle. 
   Furthermore, since the armrest main body extends in an outwardly diverging manner from the seat in the used position, the armrest main body does not approach a seating space too much so as to have sufficient area to support arms and to be capable to support a passenger&#39;s arm at a comfortable position. 
   In addition, while the armrest according to various embodiments of the present invention has a space-saving design, the armrest is switchable between the stowed position and the used position in a single motion: more specifically, it is switchable to the used position simply by lowering the armrest main body and to the unused position simply by raising it. Therefore such an armrest is easy for passengers to use. 
   Furthermore, as the armrest comprises few parts so as to be easy to assemble, the number of assembling steps is decreased and manufacturing cost is reduced. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is illustrated below with reference to various embodiments shown in the drawings and described in more detail below. 
       FIG. 1  is a pictorial view of an armrest and a seat according to and embodiment of the present invention; 
       FIG. 2  is a sectional view taken along line A-A of  FIG. 1 ; 
       FIG. 3  is a front view of the armrest in an unused position and the seat; 
       FIG. 4  is a plan view of the armrest in the unused position and the seat; 
       FIG. 5  is a pictorial view of the armrests in a used position and in the unused position and the seats; 
       FIG. 6  is a sectional view of an alternative embodiment taken along line B-B of  FIG. 1 ; 
       FIG. 7  is a pictorial view of a prior art embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   An embodiment of the present invention will be described with reference to the accompanying drawings. It is to be understood that the present invention is not limited to the specific construction and arrangement of parts described below, and variations may be made without departing from the spirit and scope of the invention. 
     FIGS. 1 through 5  illustrate an embodiment of the present invention. 
     FIG. 1  illustrates a seat S having an armrest  10  as viewed from the side. In  FIG. 1  the armrest  10  is illustrated in a stowed position. Reference numeral  30  indicates a seat portion of the seat S. 
   The armrest  10  of this embodiment is mounted to a side portion of a seat back  20  of the seat S of an automobile. The armrest  10  comprises an armrest main body  11  and a pivot shaft  12  corresponding to a pivot member, and the armrest main body  11  is pivotally mounted to the seat back  20  via the pivot shaft  12 . 
     FIG. 2  is a sectional view taken along line A-A of  FIG. 1  illustrating the seat S and the armrest  10  as cut along line A-A and viewed from above.  FIG. 2  illustrates the construction of the armrest  10  and its attachment to the seat back  20 . 
   The armrest main body  11  comprises a frame  13  and a pad  14  integrally disposed to the frame  13 . The outside of the pad  14  is covered with a skin member, not shown in  FIG. 2 . 
   The frame  13  and the pad  14  are formed with a hole  15 . The hole  15  has a diameter sized to engage the pivot shaft  12 . The armrest main body  11  is mounted to the seat back  20  via the pivot shaft  12 . 
   The seat back  20  comprises a back frame  21 , a pad  22  and a bracket  23  to which the armrest is mounted. The outside of the pad  22  is covered with a skin member, not shown in  FIG. 2 . 
   The pivot shaft  12  is secured to the bracket  23  and projects therefrom. The pivot shaft  12  is provided with a pivot part  12   a  engaged with the hole  15  of the armrest main body  11  at the distal end. The pivot part  12   a  is made of resin and structured such that the armrest main body  11  can smoothly slide and rotate around the pivot shaft  12 . A nut  12   b  is screwed to a distal end of the pivot part  12   a  and secures the armrest main body  11  to the pivot shaft  12  so as to prevent the armrest main body  11  from falling out of the pivot shaft  12 . 
   The lower side of  FIG. 2  corresponds to the front side of the vehicle. As illustrated in the figure, the side portion of the seat back  20  has a slant surface  24  tilted at a substantial angle relative to a horizontal axis y in a fore-aft direction of the vehicle as the slant surface  24  extends from a front to a rear. 
   The pivot shaft  12  is mounted to the slant surface  24  so as to be positioned at a substantial angle relative to the slant surface  24  such that an inner side of the armrest  10  is approximately parallel to the slant surface  24  when the armrest  10  is raised. The pivot shaft  12  of this embodiment is positioned at an angle of approximately 90 degrees relative to the slant surface  24 . 
   Regarding a positional relationship between the seat S and the pivot shaft  12 , the pivot shaft  12  is skewed toward the vehicle rear at a substantial angle relative to a widthwise horizontal axis x of the seat S as it extends from a base to a distal end. The pivot shaft  12  of this embodiment is skewed horizontally at an angle  1  relative to the horizontal axis x. 
   The armrest main body  11  of this embodiment is mounted to the side portion of the seat back  20 , and the pivot shaft  12  is tilted corresponding to the slant surface  24  of the side portion of the seat back  20 . Thus when the armrest main body  11  is raised at the side of the seat back  20 , the armrest main body  11  moves toward a back side of the seat back  20  and is positioned upright in close proximity to the slant surface  24 . 
   The angle of the pivot shaft  12  relative to the slant surface  24  is not limited to 90 degrees; it may be another angle. By selecting the angle of the pivot shaft  12 , the amount of travel to the used position of the armrest main body  11  in a lateral direction and the positional relationship between the stowed armrest main body  11  and the seat back  20  can be adjusted. 
   As the angle between the pivot shaft  12  and the slant surface  24  becomes more acute, that is, the angle  1  becomes greater, the armrest main body  11  extends in a more outwardly diverging manner from the seat S and a spacing between the armrest main body  11  and the seat S in the used position increases. At the same time the armrest main body  11  is positioned closer to the seat back  20  in the stowed position. 
   As the angle between the pivot shaft  12  and the slant surface  24  becomes more obtuse, that is, the angle  1  becomes smaller, the armrest main body  11  becomes closer to the seat S in the used position, and is raised further away from the seat back  20  in the stowed position. 
     FIGS. 3 through 5  illustrate the armrests  10  in the used position and in the unused position. 
     FIG. 3  illustrates the armrest  10  in the unused position; more specifically, it illustrates the armrest main body  11  being stowed upright at the side of the seat back  20 .  FIG. 3  illustrates the armrest  10  and the seat S viewed from the front of the vehicle. 
   As illustrated in the figure, the side portion of the seat back  20  is tilted inwardly as it extends from a substantial center to an upper part in front view, and an inner side of the armrest main body  11  is tilted along the side portion of the seat back  20 . Thus, when stowed, the armrest main body  11  is positioned upright in close proximity to the side portion of the seat back  20 . 
   The armrest main body  11  is formed such that a surface  16  thereof opposite the seat back  20  is approximately perpendicular to a vehicle floor when mounted to the side portion of the seat back  20 . Therefore, when stowed at the side of the seat back  20 , the armrest main body  11  does not intrude into vehicle interior space and sufficient walk-through space is maintained. The armrest main body  11  of this embodiment is formed such that a top of the surface  16  approximately perpendicular is inclined toward the seat back  20  to correspond with an exterior shape of the seat back  20  when mounted to the side portion of the seat back  20 . 
     FIG. 4  illustrates the armrest main body  11  stowed at the side of the seat back  20 , as viewed from above the seat S. A width w of the armrest main body  11  defines a width of a support surface for supporting a passenger&#39;s arm when the armrest  10  is in use. As the slant surface  24  of the seat back  20  becomes steeper, that is, the angle  2  becomes greater, the width w of the support surface of the armrest  10  becomes greater. 
     FIG. 5  is a pictorial view of the armrests  10  in the used position and in the unused position in the vehicle. In  FIG. 5 , the armrests  10  of rear seats are in the used position and the armrests  10  of front seats are in the unused position. The seat back  20  of the seat S of this embodiment comprises the slant surface  24 , to which the pivot shaft  12  is mounted so as to be skewed toward the vehicle rear at the substantial angle relative to the widthwise horizontal axis of the seat S as the pivot shaft  12  extends from the base to the distal end, and via this pivot shaft  12  the armrest main body  11  is pivotally attached to the side portion of the seat back  20 . Therefore, since the armrest main body  11  extends in an outwardly diverging manner from the seat S in the used position, the armrest main body  11  does not approach a seating space too much so as to support a passenger&#39;s arm at a comfortable position. 
   Reference numeral  17  in  FIG. 5  indicates a support surface  17  on which a passenger puts his or her arm when the armrest  10  is used. The armrest main body  11  is formed such that the support surface  17  is positioned horizontally in the used position. 
   The armrest main body  11  is raised at the side of the seat back  20  when the armrest  10  is not used. In this case, since the armrest main body  11  is pivotally attached to the pivot shaft  12  being skewed toward the vehicle rear at a substantial angle relative to the widthwise horizontal axis of the seat S as the pivot shaft  12  extends from the base to the distal end, the armrest main body  11  moves toward the back side of the seat back  20  and is positioned in close proximity to the side portion of the seat back  20  and stowed. 
   Furthermore, since the armrest main body  11  is formed such that the surface  16  thereof opposite the seat back  20  is approximately perpendicular to the vehicle floor when mounted to the side portion of the seat back  20 , the armrest main body  11  does not intrude into vehicle interior space. Therefore, the overall width of the seat back  20  is reduced and sufficient walk-through space  40  is maintained. 
   In this embodiment, as illustrated in  FIG. 5 , the distance between a center of the seat portion  30  and a lateral side of the armrest main body  11  is 331 mm (arrow a) in the used position of the armrest  10 , and is 277 mm (arrow b) when the armrest  10  is stowed at the side of the seat back  20 . Thus, the armrest  10  of this embodiment is stowed 54 mm more compactly in width in the stowed position than in the used position, and the width of the walk-through space  40  is 108 mm greater when both armrests  10  of adjacent seats are used than when they are stowed. 
     FIG. 6  illustrates another embodiment. In this embodiment, the same or similar reference numerals are applied to the same or similar members and arrangements as or to the previous embodiment, and their description will be omitted or simplified. 
     FIG. 6  is a sectional view taken along line B-B of  FIG. 1  as the seat S and the armrest  10  are cut along line B-B and viewed from the front. While the pivot shaft  12  of the previous embodiment is skewed horizontally at the angle  1  relative to the widthwise horizontal axis x of the seat as it extends from the base to the distal end, a pivot shaft  12  of this embodiment is skewed vertically upward at a substantial angle relative to the widthwise horizontal axis x of the seat as it extends from the base to the distal end. 
   More specifically, the pivot shaft  12  of this embodiment is mounted so as to be skewed at an angle  3  relative to the horizontal axis x, and the armrest main body  11  extends in an outwardly diverging manner from the seat S when in use. When the armrest main body  11  is being stowed, the armrest main body  11  moves toward the seat back  20  and is raised upright to be stowed in close proximity to the side portion of the seat back  20 . 
   In this embodiment, the side portion of the seat back  20  is tilted inwardly as it extends from a substantial center to an upper part in front view such that the armrest main body  11  does not interfere with the side portion of the seat back  20  when raised. 
   Though the side portion of the seat back  20  has the slant surface  24  or is tilted inwardly from the substantial center to the upper part in front view in the embodiments described above, the seat back  20  may be configured to have no such slant surfaces. In this case, the armrest main body  11  is configured to have a shape that does not interfere with the side portion of the seat back  20  when raised. 
   The particular implementations shown and described herein are illustrative examples of the invention and are not intended to otherwise limit the scope of the invention in any way. For the sake of brevity, conventional aspects of the systems (and components of the individual operating components of the systems) may not be described in detail. Furthermore, the connecting lines, or connectors shown in the various figures presented are intended to represent exemplary functional relationships and/or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections may be present in a practical device. Moreover, no item or component is essential to the practice of the invention unless the element is specifically described as “essential” or “critical”. The word mechanism is intended to be used generally and is not limited solely to mechanical embodiments. Numerous modifications and adaptations will be readily apparent to those skilled in this art without departing from the spirit and scope of the present invention. 
   
     
       
             
           
             
             
             
           
         
             
                 
             
             
               TABLE OF REFERENCE CHARACTERS 
             
             
                 
             
           
           
             
                 
             
           
        
         
             
                 
               10 
               armrest 
             
             
                 
               11 
               armrest main body 
             
             
                 
               12 
               pivot shaft (pivot member) 
             
             
                 
               12a 
               pivot part 
             
             
                 
               12b 
               nut 
             
             
                 
               13 
               frame 
             
             
                 
               14 
               pad 
             
             
                 
               15 
               hole 
             
             
                 
               16 
               surface 
             
             
                 
               17 
               support surface 
             
             
                 
               20 
               seat back 
             
             
                 
               21 
               back frame 
             
             
                 
               22 
               pad 
             
             
                 
               23 
               bracket 
             
             
                 
               24 
               slant surface 
             
             
                 
               30 
               seat portion 
             
             
                 
               40 
               walk-through space 
             
             
                 
               S 
               seat 
             
             
                 
               x 
               widthwise horizontal axis of the seat 
             
             
                 
               y 
               horizontal axis in the fore-aft direction of the vehicle 
             
             
                 
                1, 
               angle between the widthwise horizontal axis of the seat 
             
             
                 
                 
               and the pivot shaft 
             
             
                 
                2 
               angle between the horizontal axis in the fore-aft 
             
             
                 
                 
               direction of the vehicle and the slant surface of the seat back