Abstract:
This invention relates to a method of manufacturing seat back frame, wherein a pair of side back frame portions are first provided. Also provided is a first upper back frame portion having an upper surface defining a first profile is provided, and a second upper back frame portion having an upper surface defining a second profile. The second profile is different from the first profile. A desired profile of a vehicle seat back frame is then determined. After the determination, one of the first and the second upper back frame portions is selected for attachment to the pair of side back frame portions corresponding to the desired vehicle seat back frame profile determined previously. The selected one of the first and the second upper back frame portions is secured to the pair of side back frame portions.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates in general to vehicle seat frame structures. Typically, seats for use in automotive vehicles vary in size, shape, style, and function for each particular vehicle platform. Typically, each different model of seat is manufactured with a unique frame structure provided for each vehicle platform. The size and shape of the frame structure generally conforms to the size and shape of a particular seat model to be implemented in a particular vehicle. The style and function of the frame structure is generally determined by consumer desire for appearance and utility. Since each seat model is commonly manufactured with its own unique frame structure, the seat frame structure is generally manufactured for each model specific to the size, shape, style, and function of that particular model. Portions of the seat frame structure are usually not interchangeable between different seat models, regardless of vehicle platform or original equipment manufacturer. 
     BRIEF SUMMARY OF THE INVENTION 
     This invention relates to vehicle seat frame structures, and more specifically to an improved method of manufacturing seat back frame. In a first method of manufacturing a seat back frame, a pair of side back frame portions are first provided. Also provided is a first upper back frame portion having an upper surface defining a first profile, and a second upper back frame portion having an upper surface defining a second profile. The second profile is different from the first profile. A desired profile of a vehicle seat back frame is then determined. After the determination, one of the first and the second upper back frame portions is selected for attachment to the pair of side back frame portions corresponding to the desired vehicle seat back frame profile determined previously. The selected one of the first and the second upper back frame portions is secured to the pair of side back frame portions. 
     In a second method of manufacturing a seat back frame, an upper back frame portion is first provided. Also provided is a side back frame portion having a side surface defining a first profile, and a second side back frame portion having a side surface defining a second profile. The first profile is different from the second profile. A desired profile of a vehicle seat back frame is then determined. After the determination, one of the first and the second side back frame portions is selected for attachment to the upper back frame portions corresponding to the desired vehicle back frame profile determined previously. The selected one of the first and the second side back frame portion is secured to the upper back frame portion. 
     Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a perspective view of a seat structure having a frame manufactured in accordance with a first embodiment of the present invention. 
         FIG. 2  is a perspective view of an upper portion of the frame of the seat frame structure of  FIG. 1 . 
         FIG. 3  is a perspective view of a second upper portion suitable for use as the upper portion of the seat frame of  FIG. 1 . 
         FIG. 4  is a perspective view of a side back frame portion of the seat frame structure of  FIG. 1 , wherein the side portion includes a deep pocket. 
         FIG. 5  is a front elevational view of a portion of the side back frame portion of the frame of  FIG. 4 . 
         FIG. 6  is a perspective view of a second side back frame portion suitable for use as the side back frame portion of the seat frame of  FIG. 1 , wherein the second side back frame portion includes a shallow pocket. 
         FIG. 7  is a front elevational view of a portion of the second side back frame portion of the frame of  FIG. 6 . 
         FIG. 8  is a perspective view of the seat back frame of seat frame of  FIG. 1  shown having a high height upper frame portion, a deep pocket side back frame portion, and an air bag module installed thereon. 
         FIG. 9  is a perspective view of a second seat back frame shown having a low height upper frame portion, and a shallow side back frame portion. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Preliminarily, it must be noted that directional labels such as upper, lower, top bottom, above, below, over, and under are used with respect to the orientation of the figure under discussion on the page, and are not intended as limitations upon the orientation of the structure of the invention&#39;s actual use. 
     Referring now to the drawings, there is illustrated in  FIG. 1  a vehicle seat frame structure, indicated generally at  10 . The seat frame structure  10  generally includes a seat back frame, indicated generally at  12 , and a seat bottom frame, indicated generally at  14 . The back frames  12  is suitable to support a back cushion assembly (not shown), and the bottom frame  14  is suitable to support a bottom cushion assembly  11  for supporting an occupant of the seat frame structure  10 . 
     The back frame  12  and the bottom frame  14  are attached to one another via a recliner  16 . The recliner  16  can be any conventional recliner mechanism, such as manually or electrically operated, which selectively permits the back frame  12  to pivot relative to the bottom frame  14 . The seat frame structure  10  further includes a seat adjuster  18  operatively mounted to the bottom frame  14 . The adjuster  18  includes mounting structures  20  for securing the adjuster  18  to a floor or frame of a vehicle. The adjuster  18  includes two pairs of upper and lower tracks slidably disposed relative to one another. The upper tracks are mounted on the bottom frame  14 , and the lower tracks are mounted on the vehicle floor via the mounting structures  20 . The adjuster  18  can be any suitable conventional seat adjuster mechanism for permitting the seat frame structure  10  to move in a fore and aft direction relative to the vehicle floor. The adjuster  18  can also include a conventional lift mechanism  22  for permitting the front and rear portions of the bottom frame  14  to move in generally vertical directions relative to the adjuster  18  and/or floor of the vehicle. Alternatively, the seat back frame  12  could be pivotally connected to the recliner  16  instead of the bottom frame  14  to permit the lift mechanism  22  to move the bottom frame  14  independent of the back frame  12 . 
     The seat back frame  12  has a generally rectangular shape including a pair of generally vertical side back frame portions  24 . The side back frame portions  24  are on opposed sides of the seat back frame  12  and may have a mirror image shape relative to one another. The lower sections of the side back frame portions  24  are attached together by a generally horizontally extending lower back frame portion  25 . The upper sections of the side back frame portions are attached together by an upper back frame portion  26 . As will be discussed below, separate and distinct seat back frames can be manufactured by replacing the upper back frame portion  26  with a differently shaped upper back frame portion. Similarly, a separate and distinct seat back frame can be manufactured by replacing one or both of the side back frame portions  24  with differently shaped side back frame portions. The upper back frame portion  26  is suitable for attaching a headrest frame, as will be further discussed below with respect to  FIGS. 8 and 9 . 
     As best shown in  FIG. 2 , the upper back frame portion  26  is generally a two piece frame portion including a rear or first upper back frame member  28  and a front or second upper back frame member  32 . Preferably, the first upper back frame member  28  and the second upper back frame member  32  are formed from a stamped sheet of metal. However, it must be understood that the first upper back frame member  28  and the second upper back frame member  32  may be formed from any suitable material in any suitable manner. It should also be understood that the upper back frame portion  26  may be formed from a single piece or any multiple number of pieces. 
     The first upper back frame member  28  may be attached to the second upper back frame member  32  by any suitable manner. The first and second upper back frame portions  28  and  32  preferably include overlapping mating surfaces or structures  36  and  44  respectively. The upper and lower mating surfaces  36  and  44  may simply be flat overlapping planar surfaces, or alternatively, fastening type structures. It must be understood that the mating surfaces may be any suitable structure for locating and/or securing the first upper back frame member  28  and the second upper back frame member  32  relative to one another. Preferably, the first upper back frame member  28  and the second upper back frame member  32  are secured to one another by welding portions of the upper and lower mating surfaces  36  and  44  together by spot welding. The first and second upper back frame members  28  and  32  can have any number of mating surfaces. 
     The upper back frame portion  26  is operable to support a head restraint system  60 , as shown in  FIG. 8 . The second upper back frame member  32  includes two upper guide holes  40  formed in an upper surface  41  thereof. The guide holes  40  receive a pair of support posts  61  of the head restraint system  60 . Generally, the guide holes  40  provide lateral or horizontal support for the head restraint system  60 . The first upper back frame member  28  may include a pair of optional support members or tabs  34 . The tabs  34  may include slots, recesses, or apertures  27  formed therein, for receiving the posts  61 . 
     Although the upper back frame portion  26  is shown and described as being suitable for supporting a non-dynamic head restraint, such as the head restraint system  60  illustrated in  FIG. 8 , the upper back frame portion  26  could be configured to support a dynamic head restraint system. The term non-dynamic headrest refers to a headrest which may or may not be adjustable in the vertical direction or slightly tiltable, but does not move in a generally horizontal direction. Contrary, dynamic head restraint systems include headrests which are generally moveable in a horizontal direction, and sometimes also in a vertical direction, towards the head of a seat occupant. The headrest is moveably mounted on a head restraint mechanism which upon actuation, such as upon detection of a rearward impact or due to physical movement of the occupant against the seat back, to position the headrest closer to the head of the occupant to help reduce injury, such as whiplash. An example of a dynamic head restraint system for use with the present invention is disclosed in U.S. Pat. No. 6,789,845 which is hereby incorporated by reference. 
     As shown in  FIGS. 2 and 8 , the upper back frame portion  26  includes the upper surface  41  having a generally horizontal central raised surface  43  and a pair of generally horizontal side upper surfaces  52  and  54  disposed on either side of the raised surface  43 . The surfaces  43  and  52 ,  54  are connected by sloping surfaces  53  and  56 . The raised surface  43  is spaced above the side surfaces  52  and  54  by a height generally indicated by h 1 . It is noted that the side surfaces  52  and  54  are on the opposite side of the mating surfaces  44 . The side upper surfaces  52  and  54  also provide mating surfaces for connection to the vertical side back frame portions  24 . As shown in  FIG. 1 , the vertical side back frame portions  24  include inwardly extending tabs  71  formed at upper ends  73  of the side back frame portions  24 . The upper surface  41  is spaced above the upper ends  73  by approximately the height h 1 . 
     Now referring to  FIG. 3 , the present invention also contemplates the use of a second upper back frame portion  126 . The second upper back frame portion  126  can be used in place of the upper back frame portion  26  to provide a seat back frame  112 , as shown in  FIG. 9 , having a different upper profile. The upper profile of the upper back frame portion  126  is generally defined by the upper surface  141  in lieu of the raised surface  43 , the side upper surfaces  52  and  54 , and the sloping surfaces  53  and  56  shown in  FIG. 2 . The second upper back frame portion  126  is similar in function and structure as the upper back frame portion  26 , with one of the exceptions being the different upper profile defined by the upper back frame portion  126 , as will be explained below. Similar to the upper back frame portion  26 , the second upper back frame portion  126  is suitable for receiving the head restraint system  60 , or alternatively, a dynamic head restraint system (not shown). 
     The second upper back frame portion  126  is generally a two piece frame portion including a rear or first upper back frame member  128  and a front or second upper back frame member  132 . Preferably the first upper back frame member  128  and the second upper back frame member  132  are formed from stamped sheets of metal. However, it must be understood that the first upper back frame member  128  and the second upper back frame member  132  may be formed from any suitable material and by any suitable manner. It should also be understood that the upper back frame portion  126  may be formed from a single piece or any multiple number of pieces. 
     The first upper back frame member  128  may be attached to the second upper back frame member  132  by any suitable manner. The first and second upper back frame portions  128  and  132  preferably include overlapping mating structures or surfaces  136  and  144  respectively. The upper and lower mating surfaces  136  and  144  may simply be flat overlapping planar surfaces, or alternatively, fastening type structures. It must be understood that the mating surfaces may be any suitable structure for locating and/or securing the first upper back frame member  128  and the second upper back frame member  132  relative to one another. Preferably, the first upper back frame member  128  and the second upper back frame member  132  are secured to one another by welding portions of the upper and lower mating surfaces  136  and  144  together by spot welding. 
     The second upper back frame portion  126  is operable to support the head restraint system  60 , as shown in  FIG. 9 . The second upper back frame member  132  includes two upper guide holes  140  formed in an upper surface  141  thereof. The guide holes  140  receive the pair of support posts  61  of the head restraint system  60 . Generally, the guide holes  140  provide lateral or horizontal support for the head restraint system  60 . The first upper back frame member  128  may include a pair of optional support members or tabs  134 . The tabs  134  may include slots, recesses, or apertures  127  formed therein, for receiving the posts  61 . 
     As shown in  FIGS. 3 and 9 , the second upper back frame portion  126  includes the upper surface  141  which is substantially flat across the width of the second upper back frame portion  126 . It does not include the sloping surfaces  53  and  56  of the first upper back frame portion  26 , and therefore, has a different shape or profile along its upper surface  141 . The relatively flat upper surface  141  generally defines the upper profile of the second upper back frame portion  126 . As stated above, the second upper back frame portion  126  may be used in place of the first upper back frame portion  26 . As shown in  FIGS. 8 and 9 , the first upper back frame portion  26  is used to form the seat back frame  12  of  FIG. 8 , and the second upper back frame portion  126  is used to form the seat back frame  112  of  FIG. 9 . Both seat back frames  12  and  112  could use the same common generally vertical side back frame portions  24  and lower back frame portion  25 . Thus, two different seat back frames having different upper profiles can be manufactured by simply selecting one of the first and second upper back frame portions  26  and  126 . Generally, the seat back frame  12  has a higher height than the seat back frame  112  due to the height h 1  spacing of the first upper back frame portion  26 . 
     One of the advantages of replacing the first and second upper back frame portions  26  and  126  with one another is that different sized and profiled seat back frames  12  and  112  can be assembled together using other common frame members, such as the vertical side back frame portions  24  and lower back frame portion  25 . The frames  12  and  112  may have different cushions and trim material installed thereon for creating different seats. In the past, different seats were made from entirely different side members and cross members. These seats were reengineered and designed and then had to undergo expensive safety tests to determine their strength under certain loads. Another advantage of the method of manufacturing a seat frame of the present invention is that since common and similar frame members are used, reengineering costs are reduced. 
     In another embodiment of the present invention, the side back frame portions  24  are replaced with different side back frame portions  124 , instead of changing the upper back frame portion  26  and  126  as discussed above. As will be explained below, this replacement of the side back frame portions  24  and  124  is ideal for forming seat back frames depending on whether they include an air bag assembly attached thereto. 
     There is illustrated in  FIGS. 4 and 5  a first embodiment of a side back frame portion  24  for forming the seat back frame  12  of  FIG. 8 . The side back frame portion  24  is preferably formed from a single piece of stamped metal having a generally C-shaped cross-section. The side back frame portion  24  includes an outer side surface  51 . The side surface  51  is generally the outermost inboard or outboard surface of the seat back frame  12 , and thus defines the side profile of the seat back frame  12 . An inwardly extending recess or pocket  48  is formed in the side surface  51 . The pocket  48  defines a bottom wall  52 , and a plurality of side walls  54 ,  55 , and  56 . The bottom wall  52  is spaced from the side surface  51  by a maximum depth d 1 . The pocket  48  is relatively deep when comparing the depth d 1  to a width w 1  between the side surface  51  and an inward edge  57  of the side back frame portion  24 . Preferably, the depth d 1  is greater than half of the width w 1 . 
     This deep pocket  48  is ideally suited for housing an air bag assembly  200 , as shown in  FIG. 8 . The air bag assembly  200  is disposed in the pocket  48 . Depending on the size of the air bag assembly  200 , the air bag assembly  200  may be completely disposed in the pocket  48  or extend beyond the side surface  51 . Preferably, the pocket  48  is sized to house many different types and sizes of air bag assemblies, and thus the seat back frame  12 , or more particularly, the side back frame portion  24  need not be replaced depending on which air bag assembly is selected to be installed. The air bag assembly  200  includes a folded air bag (not shown) disposed within a housing  202  which inflates in the event of an impact for restraining the movement of the seat passenger. The air bag assembly  200  may further include an inflator (not shown) for the storage of propellant for inflating the air bag. A hinged door  204  may be attached to the housing  202 . The door  204  covers the air bag and is movable to an open or deployed position when the air bag is inflated. A bracket (not shown) may be used to attach the air bag assembly  200  to the side back frame portion  24 . Different brackets may be used to accommodate different air bag assemblies. 
     Referring now to  FIGS. 6 and 7 , a second side back frame portion  124  may be used in place of the first side back frame portion  24 . The side back frame portion  124  is preferably formed from a single piece of stamped metal having a generally C-shaped cross section. The side back frame portion  124  includes an outer side surface  151 . The side surface  151  is generally the outermost inboard or outboard surface of the seat back frame  112  of  FIG. 9 , and this defines the side profile of the seat back frame  112 . An inwardly extending recess or pocket  148  is formed in the side surface  151 . The pocket  148  defines a bottom wall  152 , and a plurality of relatively small side walls  154 ,  155 , and  156 . The bottom wall  152  is spaced from the side surface  151  by a maximum depth d 2  relative to the width w 2 . The pocket  148  is relatively shallow compared to the depth d 1  of the pocket  48 . The shallow pocket  148  of the side back frame portion  124  may be used to house a relatively narrow air bag assembly (not shown), or alternatively for not receiving an air bag assembly. The side back frame portion  124  generally intrudes less into the interior of the seat back frame  112  than the side back frame portion  24  intrudes into the interior of the seat back frame  12 . Thus, if the desired seat which is being manufactured does not require an air bag assembly, the side back frame portion  124  would preferably be selected to provide more room and comfort for the seat passenger. 
     Even if no air bag assembly is mounted within the pocket  148  of the second side back frame portion  124 , the formation of the walls  152 ,  154 ,  155 , and  156  of the pocket  148  provides strengthening features of the side back frame portion  124  to help prevent the side back frame portion  124  from bending or buckling during stress. 
     While the principle and mode of operation of this invention have been explained and illustrated with regards to particular embodiments, it must be understood, however, that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.