Abstract:
A seat for use by an occupant in a vehicle. The seat includes a seat base configured to be supported in the vehicle. A back frame including a first transverse member, a first side member and a second side member, wherein the first transverse member interconnects each of the side members at a location toward an upper end of the back frame. The back frame further includes a second transverse member interconnecting the first and second side members a spaced distance from the first transverse member. A compliant back member having a first end operably connected to the first transverse member and a second end operably connected to the second transverse member. A biasing member having a first end operatively engaging the compliant back member and a second end being anchored with respect to the back frame wherein when a seat occupant&#39;s back applies a force to the compliant back member, the biasing member applies a reaction force.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/519304 filed Nov. 11, 2003, and incorporated herein by reference in its entirety. 
     
    
     FIELD  
       [0002]     The present invention relates generally to the field of seats and more particularly relates to a seat having a compliant back member such as an automotive seat having a seat back having a flexible member.  
       BACKGROUND  
       [0003]     It is known to provide a chair or seat having a compliant back member pivoted to a seat back frame assembly in at least two vertically spaced-apart locations for providing a controlled curvilinear flexure support. For examples of the above, see U.S. Pat. Nos. 5,871,258; 5,909,923; 5,975,634; 5,979,984; 6,079,785; 6,086,153; 6,220,661 which disclose a office chair including a compliant back member. The prior art office chair has significant drawbacks in terms of its packaging and that it does not include a balanced seat back adjustment device for controlling the compliant back member.  
         [0004]     It is also known to provide an automotive seat having an adjustable lumbar consisting of a flexible member having a first end anchored and a second end moved with respect to the first end to cause the flexible member to vary its shape to provide adjustable support within the lumbar region of an automotive seat. For example, U.S. Pat. Nos. 5,397,164; 5,498,063; 5,626,390; 5,775,773; 6,003,941; and 6,254,187, each disclose known adjustable lumbar devices including a flexible member. However, none of these devices are capable of working with a compliant back member similar to that known in the prior art. Further, none of the known adjustable lumbar devices disclose or teach an adjustment mechanism having sufficient strength and robustness as required to apply the compliant back member of the known chair art to a vehicle seat. Further, it is known to provide a compliant back member in a vehicle seat including a tension adjust member using a Bowden cable arrangement. For example, PCT Patent Application No. PCT/US03/04210, filed Feb. 11, 2003, entitled Automotive Seat with Live Back, discloses such a device.  
         [0005]     Notwithstanding the known devices, there remains a significant and continued need to develop a seat which is capable of better supporting an occupant of the seat using a more simple device. In particular, there remains a need to provide an automotive seat which is capable of providing continuous support for a plurality of sizes of seat occupants while reducing the complexity and cost of known devices and designs. Further, there remains a need to provide an automotive seat that includes a compliant or flexible seat back that automatically adjusts to an occupant&#39;s unique shape and posture including being able to adjust to the occupant&#39;s changing shape and posture while providing continuous support. Further, there remains a need to provide an automotive seat having a seat back that is capable of providing an occupant with individualized support and which is capable of permitting back and spinal motion. There also remains a need to provide an automotive seat having a seat back that can pivot more naturally in relation to an occupant and which is capable of better keeping the a lumbar support in contact with the occupant.  
         [0006]     It is desirable to provide an automotive seat that provides one or more of these and other advantageous features. Other features and advantages will be made apparent from the present description. The teachings disclosed extend to those embodiments that fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.  
       SUMMARY OF THE INVENTION  
       [0007]     One embodiment of the invention relates to a vehicle seat for use by an occupant in a vehicle. The vehicle seat comprises a seat base coupled to a support structure of the vehicle. A back frame including a first or upper transverse member or portion, a first side member or portion and a second side member or portion wherein the upper transverse member or portion interconnects each of the side members or portions at a location toward an upper end of the back frame, the back frame further includes a second or lower traverse member or portion, coupled to the first and second side members or portions a spaced distance from the first traverse member or portion. In one embodiment, the back frame may be as a single element or may be made of any number of integrated pieces.  
         [0008]     A compliant back is operably connected at a location toward a first or upper end to the first traverse member and operably connected at a location toward a second or lower portion to the coupled to the second traverse member by at least one slidable pivot member. In one embodiment the compliant back is operably connected at its lower end. and is further provided with a seat back biasing member for biasing the compliant back with respect to the back frame.  
         [0009]     The biasing member preferably includes a first and second spring members disposed adjacent one another and each having a first end having a roller member engaging a lumbar portion of the compliant back member and a second end anchored with respect to the seat back frame such that the first and second spring members bias the roller members against the lumbar portion of the compliant back. In one embodiment, the first and second spring members are preferably in the form of clock or coil springs being wrapped around a shaft or rod and the second ends of the springs are anchored on the shaft. The shaft is preferably journaled in the seat back frame and is rotatable such that when the shaft is rotated the amount of energy stored in each of the first and second springs is adjusted. An additional embodiment includes a drive motor coupled to the shaft to rotate the shaft and adjust the amount of tension in the first and second spring members. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a front view of an exemplary embodiment of a vehicle seat.  
         [0011]      FIG. 2  is a side view of an exemplary embodiment of a vehicle seat.  
         [0012]      FIG. 3  is a side view of an exemplary embodiment of the vehicle seat illustrated in  FIG. 2  depicting proportionate movement of the back in relation to the seat.  
         [0013]      FIG. 4  is an exploded perspective front view of an exemplary embodiment of a seat back of the exemplary vehicle seat with the covers and cushions removed. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0014]     Before beginning the detailed description of the preferred and exemplary embodiments, several general comments are warranted about the applicability and the scope of the present invention. First, the illustrations relate to a seat (also referred to as a chair) particularly adapted for motor vehicles, such as cars, SUVs, vans, trucks, buses and the like, but the invention is applicable also to seating used in other vehicles such as aircraft, railroad, nautical or others as well as other non-vehicle applications such as office chairs and other similar environments.  
         [0015]     Second, the seat of the present invention is illustrated in the first few FIGURES as a padded seat having certain contours, trim and the like. While this configuration is presently preferred, a wide variety of seat configurations and appearances will benefit from use of the mechanical support and movement mechanisms described in connection with the later FIGURES. Also the exterior of the seat can be covered by fabric, vinyl, leather or other materials known and used in the seating art. Third, with regard to the seat described herein, substantial modifications can be made without departing from the invention&#39;s intended scope. For example, while certain mechanical systems are described to move seat components to achieve certain results, other mechanisms, manual or powered could be substituted therefore. For example, where a motor is used in moving a member, other mechanical equivalents including, but not limited to, linkages, pneumatics, rack and pinion systems, cams and cables, gears, etc. could be employed. These particular mechanisms do not, in and of themselves, form the present invention, but when combined with the other pivot, support, rotation and moving mechanisms define the invention and result in more comfortable seating for the occupant as defined herein.  
         [0016]     Referring generally to the Figures and in particular to  FIGS. 1-3  there is shown a vehicle seat  10  for use in a vehicle  5  of any known type. The vehicle seat  10  includes a seat base  12  and a seat back  14  pivotally connected to the seat base  12 . The seat  10  can be either a manually adjustable seat or may be provided with electric motors to provide automated adjustment and electronic control of the seat. Such manipulation can be accomplished by the use of a change of position mechanism  70  coupled to a back frame  40  and seat base  12 . The change of position or recliner mechanism provides for the back frame  40  to move in relation to the seat base  12 .  
         [0017]     The seat  10  is connected to the floor of the support structure  6  of a vehicle  5  in any of a variety of configurations or designs which allow for the movement and adjustment of the seat  10  within the vehicle  5 . The vehicle seat  10  may optionally include a headrest (not shown) which may also be adjustable with respect to an occupant of the seat  10  such as any known or appropriate headrest.  
         [0018]     The seat back  14  of the vehicle seat  10  preferably includes a central portion cushion  16  and a pair of side bolsters  18  positioned on the sides of the central portion cushion  16 . The cushion  16  is preferably contoured to receive and support the back lumbar of an occupant of the vehicle seat  10 . The side bolsters  18  are also preferably aligned with respect to the cushion  16  and contoured to provide an angled, gradual support of the lateral side portions of an occupant of the vehicle seat  10 . The cushion  16  and side bolsters  18  preferably include a foam material and a cover of any appropriate or known material such as cloth, vinyl, leather, etc. The cushion  16  and bolsters  18  preferably include support frame members as more fully described below.  
         [0019]     The seat back  14  further preferably includes a back frame  40  including a cover of any appropriate or known material such as cloth, vinyl, leather, etc. and which preferably matches the cover material of the seat  10 , back cushion  16 , side bolsters  18  and seat base  12 . However, it should be understood that a different material may be used on any element.  
         [0020]     Referring now to  FIG. 4 , there is shown an exploded view of the seat back  14  of  FIGS. 1-3  with the cover material and foam cushions removed. The back cushion  16  includes a compliant back member  60  as more fully described below. The back frame  40 , with the cover removed, includes a back frame member  42  consisting of a first side member  41  and a second side member  43 . The back frame member  42  is provided with lower ends  48 ,  50  of the first and second side members  41  and  43 , respectively, which are preferably pivotally attached to the seat base  12 . The vehicle or automotive seat  10  may alternatively includes an electric drive motor coupled to articulate the movement of the back frame  40  in relation to the seat base  12 .  
         [0021]     The word “compliant”, as used in the compliant back member  60 , is used herein as intended to refer to the flexibility of the present back especially in the lumbar area or a back structure that provides the equivalent of that flexibility, and the present back member or shell is compliant and designed to work sympathetically with the human back. The word “sympathetically” is intended to mean that the back member moves in close harmony with a seated user&#39;s back and posturally supports the seated user&#39;s back as the seat back is reclined and when a seated user flexes his/her lower back. The back member has three specific regions, as does the human back, those being the thoracic region, the lumbar region and the pelvic region.  
         [0022]     The compliant back member  60  includes a lower or second portion  61 , an upper or first portion  62  and a slotted, flexible portion  63  intended to be aligned with and conform to the lower or lumbar back portion of an occupant of the seat  10 . The compliant back member  60  further preferably includes a middle portion  64  located between the lower portion  61  and upper portion  62  for connecting the compliant back with an upper transverse member  46  of the seat back frame  40 . Expanded side portions  65  extend from the middle portion  64  and the upper portion  62  above the side bolsters  18  and are intended to support the upper back and extremities of an occupant of the vehicle seat  10 . The compliant back  60  can be formed as an integral, single piece or a combination or integration of parts that are bonded together such as with epoxy, adhesive, fasteners or the like.  
         [0023]     The compliant back member  60  together with its related cushioning forms a central back support for a seated occupant that is particularly comfortable and sympathetic to back movement of the seated occupant particularly in the lumbar area of the back of the occupant. The adjustment features on the assembly provide further comfort and allow a seated occupant to customize the seat  10  to meet his/her particular needs and preferences in the upright through reclined positions. A variety of constructions are contemplated for the back frame  40  and the compliant back  60  and accordingly, the examples should not be limited to only one particular style or material. For example, the back frame  40  could be entirely metal, plastic or a combination thereof and could be a single unitary piece or be numerous pieces made integral in any known or appropriate manufacturing process.  
         [0024]     The back frame member  42  further preferably includes a first or upper transverse or cross member  46  and a spaced distance lower toward the ends  48  and  50  of the first and second sides  41  and  43 , a second or lower transverse or cross member  44 . The first transverse member  46  is preferably aligned with the middle portion  64  of the compliant back member  60  and connects or interconnects the first and second side members  41  and  43  of the back frame  40  to provide structural rigidity to the seat back frame member  42 . The compliant back member  60  is preferably pivotally attached at a pair of pivots  68  to the first transverse member  46  such that the upper portion  62  and the side portions  65  of the compliant back member  60  extend in a cantilevered fashion over the upper portion of the seat back frame member  42 . Any known or appropriate attachment or fastener is used for the pivots  68  to pivotally connect the compliant back  60  to the first transverse member  46 .  
         [0025]     Similar to the above, the second transverse member  44  is preferably aligned with the lower portion  61  of the compliant back member  60  and connects or interconnects the first and secondside embers  41  and  43  of the back frame  40  to provide structural rigidity to the seat back frame member  42 . The lower portion  61  of the compliant back member  60  is preferably pivotally connected to the seat back frame member as described below. The second transverse member  44  preferably includes first and second blocks or tension adjust support members  49 . It should be noted that the transverse members  44  and  46  may be manufactured or formed as tubular, angle iron or a stamping or have any known or appropriate cross sectional shape or design.  
         [0026]     The lower portion  61  of the compliant back member  60  includes a connecting member in the form of a pair of glide blocks  66  for slidably and pivotally connecting the lower portion  61  with respect to the lower ends  48 ,  50  of the first and second side members  41  and  43  of the back frame  40 . The glide blocks  66  are preferably formed as part of the compliant back  60  but may be made integral with the compliant back  60  or otherwise attached in any appropriate manner or method. The glide blocks preferably each include a passage or slot  67  designed to have an angle to accommodate the pivoting and translation of the compliant back member  60  and allow the lower end  61  to move as the occupant&#39;s weight is applied to the lumbar region  63  of the compliant back member  60 .  
         [0027]     The vehicle seat  10  further includes a bias member or apparatus  100  which operates to bias the lumbar portion  63  of the compliant back member  60  about the lower end  61  pivot points defined by the support towers  49  connected to the lower transverse member  44 . The bias member  100  at its first end includes a pair of slides in the form of rollers  102  which are aligned to engage the compliant back member  60  in its lumbar region  63 . The rollers  102  are connected to a shaft  103 . The bias member  100  preferably includes a first biasing member  105  in the form of a clock spring having a first end  106  for engaging the shaft  103  and a second end  107 . The bias member  100  preferably includes a second biasing member  115  in the form of a clock spring having a first end  116  for engaging the shaft  103  and a second end  117 . The first ends  106  and  116  preferably engage the shaft  103  to bias the shaft  103  and rollers  102  toward the compliant back member  60 .  
         [0028]     The bias member  100  further preferably includes a lateral support member or bracket  120  connected at a first end  122  with the shaft  103 . The lateral support bracket  120  carries the shaft  103  preferably such that a force applied to the compliant back member  60  in the lumbar region  63  is distributed more evenly to the first and second bias members  105  and  115 . The lateral support member  120  preferably has a second end  124  located distal from the first end  122  and toward the lower end  61  of the compliant back member  60 .  
         [0029]     The biasing apparatus  100  is preferably adjustable and includes a biasing member adjuster  110  which preferably includes a shaft  111  fixedly connected to the second ends  107  and  117  of the first and second bias members  105  and  115 . Thus rotation of the shaft  111  causes the ends  107  and  117  of the clock spring bias members to rotate and store either more or less energy in the first and second bias members  105  and  115 , respectively, to effect the amount of lower back tension within the compliant back member  60 . The adjuster  1   10 , may be operated by a manual system or more preferably by an electric motor  130  coupled to the shaft  111 , with any known or appropriate convenient controls.  
         [0030]     For purposes of this disclosure, the term “coupled” means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components or the two components and any additional member being attached to one another. Such joining may be permanent in nature or alternatively may be removable or releasable in nature  
         [0031]     While the drawings and examples described herein include various exemplary embodiments, they serve the purpose of illustrating the invention only. The inventions disclosed are not limited to the specific forms shown. The systems and methods depicted and described are not limited to the precise details and conditions disclosed. Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangements of the exemplary embodiments without departing from the scope of the invention as expressed in the appended claims.