Patent Document

FIELD OF THE INVENTION  
         [0001]    This invention relates generally to wheelchairs and to accessory items and assemblies for use with wheelchairs. More particularly, it relates to a flexible backrest support assembly that can be easily adjusted to fit the contours of a user&#39;s back.  
         BACKGROUND OF THE INVENTION  
         [0002]    Conventional wheelchairs are normally equipped with a “sling-type” backrest. That is, the backrest consists of a web of material that extends between two generally upright support members located to the rear of the wheelchair and adjacent the user&#39;s back. Wheelchairs have been constructed using such webs or slings for many years because such a configuration permits easy folding and storage of the wheelchair. As originally intended, such wheelchairs were used, and are still used, for short terms and for very transient situations where a patient spends only that amount of time in the chair as it takes to go from one point to another within a healthcare facility. Such chairs were not really designed with long term usage in mind. However, prolonged use of a sling-type wheelchair backrest may negatively affect the user&#39;s posture, comfort and overall health. In fact, long-term wheelchair users frequently develop a condition known as kyphosis, a front to back curvature of the spine. In the experience of this inventor, conventional web or sling-type backrests fail to provide any lateral support whatsoever. Over time, this lack of support can lead to a condition known as scoliosis, or sideways curvature of the spine. In the case of the institutionalized patient or the wheelchair user who must spend the greater part of his or her waking hours in such a chair, prior web or sling-type backrests are completely unacceptable.  
           [0003]    Considering the above enumerated problems, there has long been a need for improvement in the art of producing wheelchairs and wheelchair back supports in particular. Unfortunately, inventors in this area face numerous problems. As alluded to, wheelchair users require the low weight, flexibility, foldability and simplicity of prior designs but also recognize that persons who need the assistance of a wheelchair often have other special needs not met by prior designs.  
           [0004]    In response to these conflicting needs, adjustable tension seat backs have been introduced. These innovations attempted to preserve the low weight, flexibility and foldable characteristics of earlier chairs while accommodating users with the aforementioned spine and back problems. Unfortunately, these back supports still frequently fail to provide adjustments to accommodate the wide variety of users that use such chairs.  
           [0005]    Another problem that wheelchair designers frequently face is that the end user is often not a specific individual with specific problems, but an assisted care facility with numerous individuals having a wide variety of problems. Therefore, a wheelchair that can be easily adjusted and readjusted for numerous users is required.  
         SUMMARY OF THE INVENTION  
         [0006]    It is, therefore a principal object of the present invention to provide a new, useful, and uncomplicated assembly for providing improved back support for a wheelchair user. It is a further object of this invention to provide such an assembly having means for lateral back support for the wheelchair user. It is also an object of this invention to provide such an assembly that requires only a minimal number of elements and a minimal amount of steps to utilize. It is yet another object of this invention to provide such an assembly that can readily be used by a wide variety of wheelchair occupants having upper body weakness or spinal deformities of every nature. It is still another object of this invention to provide such an assembly that is readily and quickly adjustable so as to accommodate the many shapes and sizes of persons needing to use the wheelchair that is equipped with the assembly of the present invention. It is still another object of this invention to provide such an assembly that may be variably used to apply support to the wheelchair occupant&#39;s back and rib cage area.  
           [0007]    In addition to the foregoing stated objectives, it is also an object of the present invention to provide a backrest support that is easily removable. It is yet another object of the present invention to employ a general wheelchair configuration so that present sling-back type wheelchairs can be retrofitted with this invention. It is yet another object of the present invention to provide a wheelchair support assembly that does not require tools to install and is easily moldable. It is yet another object of this invention to employ a flame retardant material in the construction of the backrest assembly.  
           [0008]    The present invention has obtained these objects. It provides for a wheelchair backrest assembly that is attachable to an ordinary wheelchair to replace the standard web or sling-type back. The backrest assembly is comprised of a rectangular frame having a central opening defined within it, said rectangular frame having sides curved forwardly to accommodate users of various sizes and shapes. The assembly of the present invention also includes a plurality of support members attached to said frame and mountable to the upright cane portions of the wheelchair. The front portion of the rectangular frame, or that portion facing the wheelchair user, is covered by a cushioned pad and the back has a plurality of pockets designed to accommodate a plurality of formable stays, said formable stays being supported solely by the top and bottom of the rectangular frame. The stays may also be made of a preformed material that is designed to accommodate a specific individual. The stays may either be removed from the pockets and formed or left within the pockets and formed or molded by hand. No tools are required. The formable stays should be of a material resilient enough to withstand frequent reforming and yet should be strong enough such that when a user reclines against the backrest, the stays remain in place. The foregoing and other features of the assembly of the present invention will be apparent from the detailed description that follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a front, top and left side perspective view of the backrest assembly of the present invention as it is installed on a conventional wheelchair.  
         [0010]    [0010]FIG. 2 is an enlarged front, top and left side perspective view of the backrest assembly shown in FIG. 1.  
         [0011]    [0011]FIG. 3 is a further enlarged rear elevational view of the backrest assembly without the central support member in place.  
         [0012]    [0012]FIG. 4 is a top plan and cross-sectioned view of the backrest assembly taken along line  4 - 4  of FIG. 3 and showing the means of attachment at the top of the backrest and the means of attachment at the bottom of the backrest.  
         [0013]    [0013]FIG. 5 is a left side elevational view of the backrest assembly.  
         [0014]    [0014]FIG. 6 is a rear elevational view of the backrest assembly and showing the central support member.  
         [0015]    [0015]FIG. 7 is a front elevational view of the outer shell portion of the backrest assembly.  
         [0016]    [0016]FIG. 8 is a rear, top and right side perspective view of the central support member of the backrest assembly and showing the pockets and stays defined within it.  
         [0017]    [0017]FIG. 9 is a left side elevational and cross-sectioned view of the backrest assembly.  
         [0018]    [0018]FIG. 10 is a front, top and left side perspective view of the one of the stays used within the central support member of the backrest assembly.  
     
    
     DETAILED DESCRIPTION  
       [0019]    The following detailed description is intended to describe the preferred embodiments that are depicted in the figures. It is to be understood that changes could be made to that which is specifically described and shown that would still fall within the scope of the present invention.  
         [0020]    Referring now to the drawings in detail, wherein like numbered elements refer to like elements throughout, FIG. 1 illustrates a preferred embodiment of backrest assembly of the present invention as it is installed on a wheelchair, generally identified  1 . The backrest assembly, generally identified  2 , is intended and designed by this inventor for use with all standard wheelchairs  1 .  
         [0021]    The backrest assembly  2  employs a thermoplastic material, such material having a high tensile and impact strength, for the outer shell portion  60  of the assembly  2 . See also FIG. 7. Thermoplastic material is preferred for its light weight and relatively easy formability. It also provides the advantages of good stiffness and strength as well as flame retarding capability. The backrest assembly  2  may also employ a Viscoback™ cushioning system. The Viscoback™ cushioning system combines a high loft cushioning system with memory foam. The cushioning system provides for accommodation of patients with sensitive bony prominences and patients who develop areas of high pressure when they use the wheelchair  1 .  
         [0022]    The outer shell portion  60  of the assembly  2  is generally in the shape of a generally planar and somewhat rectangular shell exterior  61  and an open interior  62 . The open interior  62  is also generally rectangular and generally follows the contours of the exterior  61  of the shell  60 . It is to be understood, however, that the precise shape of the shell opening  62  is not a limitation of the present invention. The backrest shell  60  may also include a pair of lateral wings  63 ,  64 . The lateral wings  63 ,  64  each extend at an angle forwardly of the plane of the backrest shell central exterior  61 . See FIG. 4. The lateral wings,  63 ,  64  can be of any shape or size but in the preferred embodiment they are approximately  3  inches wide at their widest. The lateral wings  63 ,  64  in the preferred embodiment then arcuately taper in towards the backrest shell central exterior  61  both upwardly and downwardly. See FIG. 5.  
         [0023]    In a preferred embodiment of the invention, the backrest hard shell  60  provides support for an infinitely adjustable back support central insert member  70 . This infinitely adjustable back support insert  70  is comprised of a flexible shell  71 , a pair of stays  74 ,  75 , and may include a cushioning system  78  as previously alluded to. The flexible shell  71  is configured to fit over the top  65  and the bottom  66  of the wheelchair backrest shell  60 . It is important that the entirety of the backrest hard shell  60  is covered by the flexible shell  70  so that the patient is not exposed to any of the hard backrest shell  60 . The flexible shell  71  has a pair of parallel pockets  72 ,  73  that extend from the top of the backrest shell  65  to the bottom of the backrest shell  66 . In the preferred embodiment, the flexible shell  71  is supported by a pair of aluminum stays  74 ,  75  that are inserted within the pockets  72 ,  73  of the flexible shell  71 . See FIG. 8. The aluminum stays  74 ,  75  should be long enough such that they fully extend between the top  65  and the bottom  66  of the wheelchair backrest shell  60 . It is also to be understood that the stays  74 ,  75  need not be constructed of aluminum. The stays  74 ,  75  can be constructed of any suitable material that is rigid, yet formable for the stated purpose.  
         [0024]    In a preferred embodiment, the aluminum stays  74 ,  75  are fabricated to be 1½ inch wide and about ⅛ inch thick. See FIG. 10. The stays  74 ,  75  are designed to be flexible enough to be formable by hand but stiff enough such that they stay in position when the wheelchair occupant leans against them. See FIG. 9. The stays  74 ,  75 , in turn, support the cushioning system  78 . Generally, the stays,  74 ,  75  run through the pockets  72 ,  73  and are configured to be parallel to the user&#39;s back. The stays  74 ,  75  can then be formed by the user or healthcare provider to accommodate each individual patient&#39;s back. For example, in the case of a person having kyphosis, the front to back curvature of the spine, the stays  74 ,  75  can be formed to match the curvature of the patient&#39;s spine or even used as a corrective orthotic for the patient&#39;s back. If kyphosis were the patient&#39;s only back problem, the stays  74 ,  75  would most likely be formed using the same radius of curvature. The stays  74 ,  75  can also be used to treat or to comfort patients with conditions such as scoliosis, the side to side curvature of the spine. In the case of scoliotic patients, the stays  74 ,  75  are normally individually formed to match the contours of each side of the patient&#39;s back relative to the spine.  
         [0025]    In the experience of this inventor, patients who spend a significant amount of time in a wheelchair may either have or develop scoliosis, kyphosis, or both. It is therefore important to provide an adjustable backrest assembly  2  that allows for different patient needs and conditions, while providing a corrective feature. The inventor is also aware that patients needing wheelchairs  1  come in to different shapes and sizes and envisions a tall version of the above discussed embodiment as well as a bariatric version. The bariatric version of the wheelchair assembly  2  will likely provide more support, perhaps using a stiffer material for the stays  74 ,  75 . The bariatric version may also provide a flexible backrest having either wider stays  74 ,  75  or even more stays  74 ,  75  to accommodate the physical needs of the obese patient.  
         [0026]    The flexible backrest shell  70  can be held on the rigid backrest shell  60  using any number of design contingencies, but low cost and simplicity are high priorities in this field. In the preferred embodiment shown in FIG. 2, hook and loop type fastening straps, generally identified  76 , are used to hold the flexible shell  70  on the backrest  60 . The use of such hook and loop type fastening straps  76  allows the user to remove the flexible shell  70  quickly and easily for cleaning and reconfiguration.  
         [0027]    In the preferred embodiment, the rigid shell  60  of the backrest assembly  2  is held in place at the top using a combination of angle brackets  20 ,  21  and chair hooks  40 ,  41 , and at the bottom using a pair pivot arms  30 ,  31 . The angle brackets  20 ,  21  are attached to the backrest shell  60 . It should be noted that the angle brackets  20 ,  21  offer a continuous aperture for mounting the angle brackets  20 ,  21  to the backrest shell  60 . The chair hooks,  40 ,  41  are attached to the upright wheelchair canes  10 ,  11 . There are several possible types of chair hooks but two will be discussed here. The regular chair hook  70 ,  71  provides three mounting apertures. Each mounting position corresponds to approximately 5° of recline relative to the vertical. The regular chair hook  40 ,  41  provides for approximately 10° of recline. A long chair hook (not shown) can provide up to 20° of recline. To attach the assembly  2  to the wheelchair  1 , the angle bracket  20 ,  21  is simply attached to the chair hook  40 ,  41  using a fastener of most any type. It should be noted that one should consider the amount of recline afforded the patient at this stage. The backrest shell  60  is also attached to the wheelchair canes  10 ,  11  further down on the canes  10 ,  11  using pivot arms  30 ,  31 . The pivot arms  30 ,  31 , are designed to support the backrest shell  60  regardless of the angle of recline of the backrest shell  60 . The pivot arms  30 ,  31  also offer a continuous aperture such that they can be mounted on the backrest shell  60  anywhere along their length. The importance in having the continuous apertures for mounting the backrest shell  60  using the angle brackets and pivot arms is that wheelchair producers have built many different sizes of wheelchairs over the years, but most of them can be accommodated by permitting the installer to adjust the width of the aforementioned attachments.  
         [0028]    Yet another embodiment of the device of the present invention incorporates a device comprised of a lower clip  32  and an upper locking clip  42  attached to the wheelchair cane  10 . See FIGS. 2 and 5. The user of the wheechair  1  first pulls the lower clip  32  over the pivot arm  31 . The user then positions the upper locking clip  42  on the chair hook  40 . The upper locking clip  42  has a locking slide mechanism that snaps downwardly onto the chair hook  40  when urged downwardly by the user. This system provides a quick release mechanism for the easy removal and reattachment of the wheelchair backrest assembly  2 .  
         [0029]    Yet another important feature of the present invention is the ease with which one can modify an existing wheelchair  1  having a web or sling-type support and customize that wheelchair  1  using the present invention. The present invention provides an assembly procedure involving only a few steps. First, the sling back (not shown) is removed from the wheelchair  1 . Second, the upper chair hooks  40 ,  41  are mounted to the angle brackets  20 ,  21 . Third, the lower pivot arms  30 ,  31  are mounted to the backrest shell  60  and pivot arms  30 ,  31  are mounted on the wheelchair canes  10 ,  11 . Fifth, the backrest  60  is placed in the wheelchair  1 . Lastly, the angle brackets  20 ,  21  are adjusted so that the chair hooks  40 ,  41  fit squarely over the wheelchair canes  10 ,  1  land the hard shell  60  is pressed firmly into the chair hooks  40 ,  41 .  
         [0030]    A device designed to improve the life of wheelchair users has been disclosed. The device of the present invention provides a wheelchair backrest that can be quickly and easily installed on an existing wheelchair. It also provides for an individually tailored orthotic backrest designed to fit the curvature of each patient&#39;s back. The present invention also provides for a wheelchair backrest that can recline up to 20° as such is desired or required. Lastly, the present invention provides for a wheelchair backrest that can be manually adjusted.  
         [0031]    Further, it is not the inventor&#39;s intention to limit use of this invention solely to wheelchairs. The inventor of the product envisions a line of products employing the present invention to include office chairs and even chairs for the home.  
         [0032]    Although I have very specifically described the preferred embodiments of the invention herein, it is to be understood that changes can be made to the improvements disclosed without departing from the scope of the invention. Therefore, it is to be understood that the scope of the invention is not to be overly limited by the specification and the drawings, but is to be determined by the broadest possible interpretation of the claims.

Technology Category: 1