Patent Publication Number: US-10314750-B2

Title: Sliding arm mechanism for wheelchairs

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 14/659,055, filed Mar. 16, 2015, which has been allowed, and which claims the benefit of U.S. patent application Ser. No. 13/253,622, filed Oct. 5, 2011, now patented as U.S. Pat. No. 8,991,849, which claims the benefit of U.S. Provisional Application No. 61/390,315, filed Oct. 6, 2010, each of which are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention is directed generally to wheelchairs, and more particularly, to a sliding arm mechanism for wheelchairs. 
     BACKGROUND OF THE INVENTION 
     Wheelchairs generally offer a device for individuals to move from one area to another area when they are injured, sick or are otherwise incapable of walking themselves. In some situations, such individuals, particularly those in nursing homes, may spend a large part of their days in wheelchairs. In these circumstances, it is often important from a therapeutic standpoint to provide comfort and support while these individuals are in the wheelchair for extended periods of time. To avoid fatigue, numbness, and general discomfort, wheelchairs are designed to provide comfort and support to an individual&#39;s lower body, back and upper body parts, such as the arms. In particular, for proper arm support and comfort, it is important to provide appropriately positioned arm rests attached to the wheelchairs. 
     It is also important that arm rests provide good stability as the arm rests are often used by individuals to maneuver into and out of the wheelchairs. Individuals often put a large amount of their weight onto the arm rests when positioning themselves and, therefore, the arm rests must be sturdy enough to support an individual&#39;s weight. In fact, in some circumstances, therapists may even use the arm rests on wheelchairs as a tool for helping individuals to exercise their arms and to gain strength in their upper bodies. Thus, for these reasons, it is necessary that the arm rests are able to remain in a fixed position and are strong enough to support an individual&#39;s weight. 
     Maximum support and stability is provided by wheelchairs having an arm rest in a full-length position. This position provides support for the lower forearm, generally from the elbow to the wrist area, with the hands of the individuals being able to hang down from the end of the arm rest in a natural, resting position. While there is no specific industry standard, for most wheelchairs that are commercially available, the length of the arm rest in a full-length wheelchair is generally about 13-14 inches in length. The arm rest is generally located about 2-3 inches from the front of the wheelchair, such that the arm rest is not flush with the front of the wheelchair. Instead, the arm rest is positioned a short distance from the front of the wheelchair to provide a comfortable, natural position for a user&#39;s arms. This full-length position provides the most comfort and support for a user when the user is in a natural sitting position in the wheelchair. 
     However, the full-length position offers some disadvantages when it comes to being able to access certain items that are typically used by people on a day-to-day basis. For example, when a wheelchair user wishes to use a desk or table, it is often the case that the arms of the wheelchair make it impossible for the user to get close enough to the table to eat, write, work, etc. at the desk or table. Thus, the arms of the wheelchair in the full-length position sometimes create obstacles for wheelchair users. Wheelchair users typically find themselves having to arrange their wheelchairs in a less than desirable or comfortable orientation to position themselves to be able to access the desk or table. In other scenarios, wheelchair users are often forced to adapt to finding a different way to eat, write, work, etc. altogether than at a desk or table. This makes what should be a somewhat routine activity a much more troublesome undertaking. 
     To make such access to desks and tables easier, wheelchair makers offer a variation on the full-length position, specifically known as a desk-length arm rest. With these “desk length” wheelchairs, the length of the arm rest is generally about 9-10 inches—or about 4-5 inches shorter than the full-length arm rests. Additionally, the arm rest in a desk-length wheelchair is generally located about 6-7 inches from the front of the wheelchair, such that the arm rest is about an additional 4 inches back from the full-length position. This allows a user of the wheelchair to access a desk or table when the wheelchair has desk-length arm rests. 
     In some embodiments, the arms on both the full-length and desk-length wheelchairs may be permanently attached or may be removable. Wheelchairs having permanent arms may have the arms welded in place. Alternatively, removable wheelchair arms can be removed and transferred to different wheelchairs. For example, for a wheelchair having an arm with a full-length arm rest, the arm may be removed and substituted with an arm having a desk-length arm rest. The removable arms include mechanisms for connecting and releasing the arms in the wheelchair, typically by sliding the vertical tube members of the arms into locking elements in the wheelchair. In some wheelchair models, the arms may be capable of being flipped or swung back to a position that allows a user to easily transfer on and off the seat of the wheelchair. These “swing back,” or “flip back,” wheelchairs include a flip back arm release that releases the arms and allows the arms to swing back toward the back portion of the wheelchair and, once a user has been seated, then swings forward again to reconnect to the wheelchair. In these flip-back models, the arms may also be permanent or removable, and may have either full-length or desk-length arm rests. 
     Thus, to accommodate individuals who use wheelchairs having full-length arm rests and wheelchairs having desk-length arm rests, hospitals, nursing homes and other healthcare facilities must purchase and store both types of wheelchairs, or at least both types of wheelchair arms. This increases the cost and space needed for purchasing and storing both types of wheelchairs and/or wheelchair arms. Additionally, healthcare personnel must spend time moving individuals from one wheelchair type to another, or removing and transferring wheelchair arms from one wheelchair to another. In order to reduce the inventory needed to accommodate users of both types of wheelchairs and to reduce the personnel time needed to move individuals from one type of wheelchair to another (or arms from one wheelchair to another), it would be desirable to have a single wheelchair having an arm rest that could be adjusted based on a particular user&#39;s needs. 
     In particular, it would be desirable to provide users with the flexibility and convenience of providing a wheelchair that has arm rests that may easily be adjusted between full-length and desk-length positions (and vice versa). This would eliminate the need to move individuals, or wheelchair arms, from one type of wheelchair to another, a maneuver that may be inconvenient (if not very difficult) for some individuals. It also allows individuals who regularly use wheelchairs to avoid having to make daily decisions as to whether to play cards, eat, write, etc. based on whether they wish to go through the difficulty of having to move to another type of wheelchair—a task that becomes more difficult the older or infirm an individual becomes. Providing a single wheelchair having adjustable arm rests offers individuals who use wheelchairs more independence and personal dignity when deciding how, when and where to conduct their daily activities. This also provides doctors, therapists and other healthcare workers with more options when deciding whether and what type of wheelchair to recommend to their patients, as current wheelchairs are either of the full-length position or desk-length position (but not both). 
     Therefore, a need exists to provide improved wheelchair devices for addressing the above-mentioned issues. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. 
         FIG. 1A  is a perspective view of a wheelchair having a sliding arm mechanism according to one embodiment. 
         FIG. 1B  is a perspective view of a wheelchair having a sliding arm mechanism according to another embodiment. 
         FIG. 2  is an expanded view of the sliding arm mechanism according to one embodiment. 
         FIG. 3  is a cross-sectional view of the sliding arm mechanism according to one embodiment. 
         FIG. 4A  is a cross-sectional view of the sliding arm mechanism attached to an arm of a wheelchair in a full-length position according to one embodiment. 
         FIG. 4B  is a perspective view of the sliding arm mechanism attached to an arm of a wheelchair in a desk-length position according to another embodiment. 
         FIG. 5  is a side view of a slide rail according to one embodiment. 
         FIG. 6A  is a side view of a sliding arm mechanism attached to an arm of a wheelchair in a desk-length position according to a further embodiment. 
         FIG. 6B  is a side view of a sliding arm mechanism attached to an arm of a wheelchair in a full-length position according to another embodiment. 
         FIG. 7A  is a side view of a sliding arm mechanism attached to an arm of a wheelchair in a desk-length position according to a further embodiment. 
         FIG. 7B  is a side view of a sliding arm mechanism attached to an arm of a wheelchair in a full-length position according to another embodiment. 
         FIG. 8  is a side view of an adjustable arm pad attached to an arm of a wheelchair according to a further embodiment. 
     
    
    
     While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS 
     While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will herein be described in detail representative embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. To that extent, elements and limitations that are disclosed, for example, in the Figures, Abstract, and Detailed Description of the Illustrative Embodiments, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference or otherwise. 
     Referring to the drawings, wherein like reference numbers refer to like components throughout the several views,  FIG. 1  presents an illustration of an exemplary wheelchair with a sliding arm mechanism, designated generally as  10 , in accordance with various aspects of the present disclosure. The drawings presented herein are not necessarily to scale, and are provided purely for explanatory purposes. Thus, the individual and relative dimensions and orientations shown in the drawings are not to be considered limiting. In addition, the use of spatial adjectives in the specification and claims, such as “front,” “rear,” “forward,” “rearward,” “upward,” “downward,” etc., are intended, unless explicitly indicated otherwise, to specify the comparative orientation of a given component relative to the wheelchair. 
     According to one embodiment shown in  FIG. 1A , a wheelchair having a sliding arm mechanism  10  is shown. The sliding arm mechanism  10  is attached to an arm  13  of the wheelchair. Once a user is sitting in the wheelchair, the sliding arm mechanism  10  is adapted to receive a portion of the user&#39;s lower arm, or forearm. In this particular embodiment, the sliding arm mechanism  10  is shown in a full-length position to support a user&#39;s arm extending from at least the elbow of the user&#39;s arm to the wrist/hand area, wherein all or a portion of the user&#39;s hand may extend down in a natural, hanging position. In another embodiment shown in  FIG. 1B , the sliding arm mechanism  10  is shown in a desk-length position. In the desk-length position, the sliding arm mechanism  10  provides support for less than the full length of a user&#39;s lower arm, for example, extending from a user&#39;s elbow to a distance about ⅓ to about ½ of a user&#39;s lower arm. The full-length and the desk-length positions are described in more detail below. 
     Turning to  FIG. 2 , an expanded view of the sliding arm mechanism  10  is shown. The sliding arm mechanism  10  includes a main portion  12 . The main portion  12  may be comprised of a plastic material, such as polyvinyl chloride (PVC) or polyurethane (PU), or other rigid plastic material. The main portion  12  includes a top area  14  and a bottom area  16 , as well as first and second opposing side areas  18 ,  20  and first and second opposing end areas  22 ,  24 . As discussed in more detail below, the main portion  12  includes an inner cavity  32  which is accessible via the bottom area  16 . In one embodiment, the main portion  12  may be rectangular with rounded corners connecting the first and second opposing side areas  18 ,  20  and the first and second opposing end areas  22 ,  24 , or may include other shapes which are desirable for accommodating a user&#39;s lower arm, or forearm. 
     The top area  14  may include a raised outer rim  25 , around the perimeter of the top area  14 , which is adapted for receiving an arm pad  11 . The arm pad  11  may include an arm pad cover  26  and a support  27  for attaching to the top area  14  of the main portion  12 . The arm pad  11 , including the arm pad cover  26  and the support  27 , may be attached to the top area  14  of the main portion  12  via one or more screws  28 , or via other means of attachment, such as by adhesives, rivets or other suitable means. The arm pad cover  26  may be comprised of any material that provides a comfortable surface for receiving a user&#39;s arm, such as vinyl or nylon upholstery. 
     According to the embodiment shown in  FIG. 2 , a slide rail  30  is adapted to be housed within the inner cavity  32  of the main portion  12 . The inner cavity  32  of the main portion  12  includes an elongated open area for receiving the slide rail  30 . The slide rail  30  includes a top side  33 , a bottom side  34  and a generally elongated aperture  35 . The slide rail  30  may also include a track  36  (shown in more detail in  FIG. 5 ). The slide rail  30  is removably coupled to a top part  39  of an arm of a wheelchair via any suitable coupling means, such as a screw  37 , adhesives, rivets or other suitable means of attachment. Alternatively the slide rail  30  may be permanently mounted to the top part  39  of an arm of a wheelchair. The slide rail  30  may be comprised of steel, aluminum, or any other suitable material. In some embodiments, the entire arm of the wheelchair (as shown in  FIGS. 4A and 4B ), including the sliding arm mechanism  10 , may be removable, such that it can be transferred and attached to other wheelchairs. This allows any existing wheelchair model to be equipped with an arm having the sliding arm mechanism  10  described herein. Additionally, the sliding arm mechanism  10  itself may be attachable to an arm of an existing wheelchair via any suitable type of attaching means, thus allowing the sliding arm mechanism  10  to be removed and transferred from one wheelchair to another when needed. 
     As shown in  FIGS. 2 and 3 , the slide rail  30  and the main portion  12  may be slidably coupled via a screw  40 , such as a countersunk or other type of screw, a spacer  42  and a spring  44 . Attached to the end portion of the screw  40  may be a nut  46 , such as a square nut. To slidably couple the slide rail  30  and the main portion  12 , the spacer  42  and the spring  44  are placed over the screw  40  such that they are adjacent the head of the screw  40 . The end portion of the screw  40  extends through a hole  48  in the first opposing side area  18  of the main portion  12  and extends through the elongated aperture  35  of the slide rail  30 . The nut  46  is placed on the threaded end portion of the screw  40 , thereby holding the screw  40 , spacer  42  and spring  44  in alignment. In some embodiments, the nut  46  may be adapted to fit within the track  36  of the slide rail  30 . This configuration allows the main portion  12  and the slide rail  30  to be slidably coupled, while also allowing the main portion to move in a lateral motion in a direction parallel with the top part  39  of the arm of the wheelchair. 
     When the main portion  12  and slide rail  30  are slidably coupled, the head of the screw  40  may sit flush with, or a short distance from, the surface of the first opposing side area  18  when in operation (see  FIG. 3 ). The spacer  42  may surround the head of the screw  40  and may also sit flush with, or a short distance from, the surface of the first opposing side area  18 . The spring  44  allows the head of the screw  40  and the spacer  42  to be depressed, like a push button or similar actuating device, to move the screw  40  and spacer  42  a distance inward in the direction of the second opposing side area  20 . When depressing the screw  40  and spacer  42 , the nut  46  is adapted to slide along the track  36  from one end of the elongated aperture  35  to the other. In some embodiments, the opposing ends of the elongated aperture  35  include recessed portions  59 , i.e., a recessed curve that resembles a “C,” to allow a rounded portion of the nut  46  to engage the recessed portions. This allows the main portion  12  to move over the slide rail  30  in a lateral motion in a direction parallel with the top part  39  of the arm of the wheelchair and stop when the nut  46  reaches the recessed portions  59 . By requiring that the user provide the necessary input—by pressing an actuating device, such as the screw  40  and spacer  42  combination described above—it ensures that the sliding arm mechanism  10  does not unintentionally move from one position to another. This provides for increased stability of the sliding arm mechanism  10 , which is important for users when maneuvering in and out of the wheelchair. 
     The main portion  12  may additionally include pins  60  (shown in  FIG. 2 ) positioned across the inner cavity  32  near opposing ends of the main portion  12 . The ends of the slide rail  30  may include a notch  62  for receiving the pins  60  as the main portion  12  is moved laterally in a direction parallel with the top part  39  of the arm of the wheelchair. The pins  60  help to align the slide rail  30  when it reaches an end of the main portion  12 . As shown in  FIG. 2 , two pins  60  are shown, but other number of pins  60  may be used. Alternatively, no pins may be used with the sliding arm mechanism  10 . In addition to the slide rail  30  discussed above, it is contemplated that other types of sliding mechanisms may be used, such as telescoping tubes, that allow the arm to be adjusted to different lengths. These alternative embodiments are discussed in more detail below and shown in  FIGS. 6-8 . 
       FIGS. 4A and 4B  illustrate an arm of the wheelchair with a cross-sectional view of the sliding arm mechanism  10 . The arms in  FIG. 4A and 4B  may be removable from or permanently attached to the wheelchair. In  FIG. 4A , the sliding arm mechanism  10  is positioned in a full-length position such that the first opposing end area  22  of the main portion  12  is generally a distance A from a plane parallel with a front part  50  of the arm of the wheelchair. The front part  50  of the arm of the wheelchair is substantially perpendicular to the top part  39  of the arm of the wheelchair. In the full-length position, the distance A ranges from about 1 inch to about 4 inches, and more preferably from about 2 inches to about 3 inches. In the full-length position shown in  FIG. 4A , the sliding arm mechanism  10  is positioned such that a user may rest substantially his or her entire forearm over the length of the arm pad  11 . In this position, however, a user may have difficulty moving the wheelchair up to the front of a desk or table in order to access the top of the desk or table for certain purposes, such as to eat, write, work, etc. Thus, the arms of the wheelchair in the full-length position create obstacles for wheelchair users when the arms of the wheelchair are close to the height of the desk or table, i.e., the arm pad and the table top are contacting in such a way as to prevent the wheelchair from coming close enough to allow the user to access the table or desk. Such difficulties can be overcome by moving the main portion  12  to a second position, such as that shown in  FIG. 4B . 
     In  FIG. 4B , the sliding arm mechanism  10  is positioned in a desk-length position such that the first opposing end area  22  of the main portion  12  is generally a distance B from a plane parallel with the front part  50  of the arm of the wheelchair. In the desk-length position, the distance B ranges from about 5 inches to about 8 inches, and more preferably from about 6 inches to about 7 inches. Thus, in some embodiments, the difference in the distance between the full-length and the desk-length positions is about 4 inches. 
     In the desk-length position, the sliding arm mechanism  10 , specifically the main portion  12 , is moved in a lateral motion parallel to the arm of the wheelchair in a direction away from the front of the wheelchair. In this position, a smaller area of the arm pad  11  is available for a user to rest his or her forearm. In the desk-length position, a section of the main portion  12  may extend beyond the back portion of the wheelchair (see  FIG. 1B ). In some embodiments, the length of the section of the main portion that extends beyond the back portion of the wheelchair is from about 2 inches to about 5 inches. 
     Thus, in the second position as shown in the embodiment of  FIG. 4B , the sliding arm mechanism  10  allows a user to adjust the arm of the wheelchair to allow the wheelchair to move in closer proximity to a desk or table. In this manner, the arm of the wheelchair does not hinder the user&#39;s ability to move close enough to access the top of the desk or table for certain purposes, such as to eat, write, work, etc. It should be noted that the lengths or distances described herein and shown in the respective drawings may vary with certain wheelchairs. However, it is contemplated that such variations fall within the scope of the claims and invention described herein. 
     In  FIG. 5 . the slide rail  30  and track  36  are shown in more detail, as well as the relative position of the screw  40 , spacer  42 , spring  44  and nut  46 . Once connected through the hole  48  in the first opposing side area  18  of the main portion  12  (see  FIG. 2 ) and through the elongated aperture  35  of the slide rail  30 , the screw  40 , spacer  42 , spring  44  and nut  46  slidably couple the main portion  12  and the slide rail  30  such that the main portion can move laterally a distance C in a direction parallel to the top part  39  of the arm of the wheelchair. In some embodiments, the notches  62  may receive the pins  60  (see  FIGS. 2, 4A and 4B ) as the main portion  12  is moved laterally between a full-length and desk-length position. In alternative embodiments discussed below, other sliding mechanisms may be used that provide adjustment between the full-length and desk-length positions. 
     Moreover, it is further contemplated that in addition to the full-length and desk-length positions described herein, the sliding arm mechanism  10  may be adjusted to several additional intermediate positions, i.e., half way between the full-length position and the desk-length position. One way this may be achieved is by including recessed areas or indentations (not shown) along the length of the elongated aperture  35  of the slide rail  30  (in addition to those recessed portions  59  at the ends of the elongated aperture  35 ) that allow for a portion of the nut  46 , such as the rounded portion, to engage the recessed areas or indentations. Additionally, it is further contemplated that the present concepts may also allow for an entirely adjustable sliding arm mechanism  10  in which a user can select any position along the length of the slide rail  30 . This may be accomplished, for example, by using a screw having a fitted nut which, when tightened, can be held in place. Thus, a user would have an infinite number of positions to be able to adjust the sliding arm mechanism  10 . All of the embodiments described above and herein are consistent with the goals of providing improved wheelchair devices that allow users to access desks or tables and of allowing healthcare providers to reduce the number and types of wheelchairs, or wheelchair arms, that they must purchase and store at healthcare facilities. 
     In addition to the embodiments described above in  FIGS. 1-5 , other embodiments may provide the same advantages and achieve the same goals by providing improved wheelchair devices, particularly improved arm rest devices. For example, in  FIGS. 6A and 6B , an alternative embodiment of a sliding arm mechanism  110  is shown wherein the arm pad is a telescoping arm pad attached to the top part  39  of the arm  13  of the wheelchair. In this embodiment, a telescoping portion of the arm pad moves in and out of a stationary portion, thereby shortening the arm pad to a desk-length position (as shown in  FIG. 6A ) and extending the arm pad to a full-length position (as shown in  FIG. 6B ). When in the full-length position, the telescoped portion is in alignment with the stationary portion of the arm pad. In  FIGS. 7A and 7B , another alternative embodiment is shown where a sliding arm mechanism  210  is attached to the top part  39  of the arm  13  of the wheelchair. The sliding arm mechanism  210  includes a telescoping tube mechanism having an outer tube and an inner tube. The outer tube is attached to the top part  39  of the arm  13 ; the inner tube is attached to the arm pad. The arm pad is allowed to be adjusted by pressing a push button that releases the inner tube and moves the arm pad from a desk-length position (as shown in  FIG. 7A ) to a full-length position (as shown in  FIG. 7B ). The inner tube has a plurality of holes for accepting the push button, which allows the user to also move the arm pad to various intermediate positions. 
     Additionally, a further embodiment is shown in  FIG. 8 , which illustrates a side view of an adjustable arm pad  310  attached to the top part  39  of the arm  13  of a wheelchair. The adjustable arm pad  310  includes a stationary portion and an adjustable portion. The adjustable portion may be flipped downward, via a hinge or similar device. The hinge is attached to the bottom side of the arm pad and allows the adjustable portion to be flipped down to provide a desk-length arm pad. The portion of the arm pad that is flipped down rests in a position perpendicular to the top part  39  of the arm  13 . When a full-length arm pad is desired, the portion is then flipped up and secured in alignment with the stationary portion of the arm pad. Each of the embodiments described herein, which include a sliding arm mechanism or an adjustable arm pad, may be used with removable wheelchair arms or arms that are permanently attached to a wheelchair. Moreover, each of the embodiments offer improvements for adjustable arm pads that provide increased accessibility to desks or tables. 
     While the best modes for carrying out the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.