Patent Publication Number: US-2006012148-A1

Title: Wheelchair having a leg rest assembly

Description:
RELATED APPLICATION  
      This application claims the benefit of U.S. Provisional Application No. 60/587,784 filed Jul. 14, 2004, the entire disclosure of which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      The present invention relates in general to a wheelchair and, in particular, to a leg rest assembly that may be used on a wheelchair.  
      Wheelchairs are often provided with leg rests or foot rests upon which a user may place his or her legs. The leg rests may be adjustable so that the leg rests may be raised or lowered. The mechanisms for providing leg rest adjustment are often bulky and may interfere with patient movement. Additionally, the mechanisms may require that a user lift his or her legs so that the leg rest may be lowered.  
     SUMMARY  
      In one embodiment, a leg rest assembly includes an elevating member for supporting a user&#39;s leg, which is adapted to move in a first and second direction. The leg rest assembly also includes a mechanism that can be selectively engaged and disengaged with the elevating member. The elevating member is adapted to move freely in a first direction and be prevented from pivoting in a second direction when the mechanism is engaged with the elevating member. The elevating member is adapted to move freely in both the first and second directions when the mechanism is disengaged from the elevating member.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The following detailed description of the embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:  
       FIG. 1  is an exploded perspective view of a leg rest assembly according to one embodiment of the present invention;  
       FIGS. 2A-2C  are perspective views of one embodiment of a leg rest assembly in lowered, raised, and partially raised positions;  
       FIG. 3  is a cross-sectional view of one embodiment of a leg rest assembly;  
       FIG. 4  is a perspective view of one embodiment of a leg rest assembly having a leg rest platform for support of a user&#39;s leg;  
       FIG. 5  is a perspective view of one embodiment of a wheelchair having leg rest assemblies;  
       FIG. 6  is a perspective view of one embodiment of a leg rest assembly having a securing member; and  
       FIG. 7  is a perspective view of a portion of the leg rest assembly of  FIG. 6 . 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION  
      The present invention will now be described with reference to the specific embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.  
      Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.  
      The present invention relates to leg rest assemblies. In particular, the present invention relates to leg rest assemblies that may be used on wheelchairs. The present invention also relates to wheelchairs having leg rest assemblies. The leg rest assemblies may allow free movement of a portion or portions of the assemblies in a first direction and selective movement of portions or portions of the assemblies in a second direction.  
      Referring to  FIGS. 1 and 2 A- 2 C, a leg rest assembly  10  is illustrated. The assembly  10  includes a hanger member  12 , an elevating member  14 , and a pivoting member  16 . The hanger member  12  has a hanger portion  18  and a lever  20 . The pivoting member  16  has a pivoting point  22  and an arcuate portion  24 . The arcuate portion  24  of the pivoting member  16  may be an arched area that is centered on the pivoting point  22 . The pivoting member  16  may be formed in any suitable manner to allow the elevating member  14  to be raised and lowered. The hanger member  12  and the elevating member  14  are attached to the pivoting member  16 . The lever  20  is disposed to variably engage or disengage the arcuate portion  24  of the pivoting member  16 . The pivoting member  16  may be pivoted about the pivoting point  22  in a first direction or a second direction to allow the elevating member  14  to be selectively raised or lowered. The pivoting member  16  may be freely pivoted in the first direction to raise the elevating member  14 . The pivoting member  16  may be pivoted in the second direction when the lever  20  is disengaged from the arcuate portion  24 .  
      The hanger portion  18  may have an upper portion  26  and a lower portion  28 , and the upper portion  26  and the lower portion  28  may be disposed to form a T shape. The pivoting member  16  is attached to the hanger portion. In the embodiment illustrated in  FIG. 1 , the hanger portion is attached to the upper portion  26  of the hanger portion  18 . The hanger portion  18  may be attached to the pivoting member  16  at the pivoting point  22  in any suitable manner. For example, as shown in  FIG. 1 , a screw  30  and a dowel pin  32  may be used to attach the upper portion  26  of the hanger portion  18  to the pivoting member  16  such that the pivoting member  16  may pivot about the pivoting point  22 . The dowel pin  32  may be used to ensure that the pivoting member  16  may only pivot through a desired number of positions or degrees. The upper portion  26  of the hanger portion  18  may have a notch or recess  34  that reduces the amount of space that the pivoting member  16  must occupy outside of the hanger member  12 .  
      The hanger portion  18  may be provided with any suitable attachment parts so that the hanger portion  18  may be mounted to the frame of a wheelchair (see  FIG. 5 ). For example, the hanger portion  18  may also have a hanger guide  36  that aligns the hanger member  12  with a wheelchair frame. Additionally, the hanger portion  18  may have a hanger pivot bushing  38  that may be placed in a vertical tubular member on a wheelchair frame to provide a vertical pivot axis for the leg rest assembly  10 . The hanger portion  18  may also have a hanger latch  40  that may be used to latch the hanger member  12  to a wheelchair frame. The attachment parts may be provided in any suitable manner and may be attached in any suitable way. For example, screws  42  and a spacer  44  may be used to attach the hanger guide  36 , hanger pivot bushing  38 , and the hanger latch  40 , as shown in  FIG. 1 .  
      Referring now to  FIGS. 2A-2C  and  3 , the lower portion  28  of the hanger portion  18  may have an opening  48  disposed such that the arcuate portion  24  of the pivoting member  16  may pass through the lower portion when the pivoting member pivots. The lever  20  may be attached to the hanger portion  18  in any suitable manner. For example, the lever  20  may be attached to the lower portion  28  of the hanger portion  18  by a dowel  46  that allows the lever to be moved as desired. The lever  20  may be disposed such that the lever  20  positively engages the arcuate portion  24  of the pivoting member  16  unless the lever  20  is disengaged as shown in  FIG. 3 . For example, a compression spring  50  may be provided below a first end  52  of the lever  20  such that a constant engagement force is provided to the lever  20  such that the first end  52  of the lever is in engagement with the arcuate portion  24 . The opening  48  may have a notch or seat in which a portion of the compression spring  50  may be seated so that the spring  50  does not come loose from the hanger portion  18 . Alternatively, the compression spring  50  can be attached to the inside of the opening  48  or in any other suitable manner.  
      The lever  20  may be disengaged from the arcuate portion  24  by providing pressure on a second end  54  of the lever to compress the spring  50  and release the first end  52  of the lever  20  from the arcuate portion  24 . For example, upward pressure on the second end  54  of the lever  20  may be used to disengage the lever  20  from the arcuate portion  24 .  
      In another example, the second end  54  of the lever  20  can be made to be very heavy so that gravity provides an engagement force to keep the first end  52  of the lever  20  in engagement with the arcuate portion  24 . In another example, the pivoting member  16  can be a ratchet like-mechanism. The ratchet like mechanism can be operated in conjunction with the lever  20  or the lever  20  can be replaced with a ratcheting control. It should be apparent to one skilled in the art that the structure and configuration of the lever  20  could vary greatly and the shape and configuration of the lever is not limited as described herein. In addition, it should also be apparent to one skilled in the art that the lever  20  of the leg rest assembly could be replaced by other various mechanisms that are capable of engaging and disengaging with the pivoting member  16 . For instance, the lever  20  could be replaced by a push-button, sliding tab or other mechanism capable of positively engaging with the pivoting member  16 , thus securing it in place, until the mechanism is intentionally disengaged.  
      The pivoting member  16  may have a guard or guards  64  disposed to protect the pivoting member  16  from intrusion of foreign matter and for the safety of the user. Referring now to  FIGS. 2A-2C , the pivoting member  16  may be disposed to pivot in any suitable manner. For example, the pivoting member  16  may pivot from 90° to 180° or more. In another example, the pivoting member  16  may be disposed to pivot from 90° to 180° or less. As shown in  FIG. 2A , the elevating member  14  may be in a lowered position such that the elevating member is at 90° with respect to the upper portion  26  of the hanger member  12 . The elevating member  14  may then be moved freely in a first or upward direction as shown in  FIG. 2B  such that the elevating portion  14  is in a partially raised position. The elevating member  14  may subsequently be moved to a fully raised position as shown in  FIG. 2C  such that the elevating member  14  is at 180° with respect to the upper portion  26  of the hanger member  18 . The elevating member  14  may be lowered to the position shown in  FIG. 2A  at any time by disengaging the lever  20  from the arcuate portion  24  of the pivoting member  16 .  
      The arcuate portion  24  may have a notch or notches  66  provided thereon and disposed such that the second end  52  of the lever  20  may prevent the pivoting member from pivoting in a second or downward direction while the lever  20  is engaged. For example, the second end of the lever  52  may be engaged in a notch  66  such that the elevating member  14  is in a partially raised position as shown in  FIG. 3 , and the elevating member  14  may be returned to a lowered position as shown in  FIG. 2A  by providing upward pressure on the second end  54  of the lever  20  such that the first end  52  of the lever is disengaged from the notch  66 . The notches  66  are disposed such that the pivoting member  16  may pivot freely in a first or upward direction but not in a second or downward direction while the lever  20  is engaged. When the lever  120  is disengaged from the pivoting member  16 , the pivoting member is free to move in either an upward or downward direction. The arcuate portion  24  may be provided with any suitable number of notches  66 . For example, the arcuate portion  24  may have a notch  66  every 10°. However, a larger number or smaller number of notches  66  may be provided. Alternatively, the arcuate portion  24  be a smooth surface disposed so that the lever  20  may engage the arcuate portion  24  by frictional or clamping engagement.  
      The elevating member  14  may have a hinge portion  56  attached to the pivoting member  16  by a screw  58  or in any other suitable manner. The hinge portion  56  may be attached to an area proximate the arcuate portion  24  as shown in  FIGS. 1 and 2 . The hinge portion  56  has an end  59  that may be proximate to the upper portion  26  of the hanger member  12  when the leg rest assembly  10  is assembled as shown in  FIG. 2 . The elevating member could also be formed together with the pivoting member  16  in a one-piece construction.  
      The hinge portion  56  may have a notch or recess  57  provided to accommodate the pivoting member  16 . The notch or recess  57  reduces the amount of space that the pivoting member  16  must occupy in the assembly. The elevating member  14  may further have a tube  60  attached to the hinge portion  56 . While the elevating member  14  and other portions of the leg rest assembly  10  are illustrated as tubular shaped pieces in the illustrated embodiment, it should be apparent that the elevating member and other portions of the leg rest assembly could be constructed from pieces with cross-sections of various shapes such as rectangular or oval.  
      The tube  60  may be attached to the hinge portion  56  in any suitable manner. For example, the tube  60  may be attached to the hinge portion  56  by a screw  62  as shown. The tube  60  and the hinge portion  56  may be moved in a first or upward and a second or downward direction during the operation of the assembly. The tube  60  may have holes  68  provided therein so that a leg rest, pad, or any other desired assembly may be provided on the tube  60 . The elevating member  14  could be made from one piece or could be of multi-piece construction. Furthermore, if the elevating member  14  includes a hinge portion  56  and a tube  60 , these pieces could also each be provided as a one piece, two piece, or three or more piece assembly as desired.  
      The components of the assembly  10  may be made from any suitable material. For example, the hanger member  12 , elevating member  14 , and pivoting member  16  can be made from aluminum. In another example, the hanger member  12 , elevating member  14 , and pivoting member  16  can be made from any suitable plastic, steel, stainless steel, or alloy or composite. The present invention is not intended to be limited by the type of materials used to construct the assembly  10 .  
      The operation of the assembly  10  will now be discussed further with reference to FIGS.  1 ,  2 A- 2 C and  3 . As shown in  FIG. 3 , the notches  66  in the arcuate portion  24  of the pivoting member  16  are designed to allow the arcuate portion  24  of the pivoting member  16  to urge the end portion  52  of the lever  20  downward in a ratcheting manner while pivoting in a first direction, thus allowing the elevating member  14  attached to the pivoting member to move freely in the first or upward direction. The notches  66 , however, are shaped to engage with the end portion  52  of the lever when the pivoting member attempts to pivot in a second direction, thus securely locking into position with the lever  20  and preventing the pivoting member from pivoting in the second direction. This prevents the elevating member  14  from moving in the second or downward position.  
      The elevating member  14  may be raised or elevated to the desired position easily without applying pressure to the lever  20 . For example, the elevating member  14  can be raised to the positions illustrated in  FIGS. 2B and 2C  or to any other desired position. Once the elevating member  14  is in the desired position, the lever  20  indexes into a corresponding notch  66  on the pivoting member  16  as shown in  FIG. 3 . The positive engagement between the lever  20  and the pivoting member  16  constrains the elevating member  14  from moving downward out of the desired position. Upward pressure on the lever  20  disengages the lever  20  from the corresponding notch  66  in the pivoting member  16  allowing the elevating member  14  to return to the full downward position as shown in  FIG. 2A . The assembly  10  would operate similarly if the pivoting member  16  did not have notches  66 . The elevating member  14  may be returned to the full downward position illustrated in  FIG. 2A  while the leg of a patient rests on the elevating member  14 , simply by releasing the lever  20 .  
      As shown in  FIG. 4 , the leg rest assembly  10  may have any suitable leg rest hardware attached thereto. For example, as shown in  FIG. 4 , a leg rest platform  70  may be provided by inserting a tube  71  having a leg rest platform  70  attached, into the elevating member  14 , and securing the tube as needed.  FIG. 5  shows an alternative attachment means the leg rest platform  70  is shown. The leg rest platform  70  may be attached to a bar  72  that is screwed to one or more of the openings  68  in the elevating member  14  by a screw  75 .  
      The leg rest assembly  10  may be attached to the frame  76  of a wheelchair  80  in any suitable manner. For example, as shown in  FIG. 5 , the hanger pivot bushing  38  may be inserted into a tube  78  of the wheelchair frame  76 . The hanger guide  36  may be placed into a hanger guide receiving portion  82  of the wheelchair frame  76 , and the hanger latch  40  may be latched to a hanger latch portion  84  on the wheelchair frame  76 .  
      As shown in  FIG. 6 , the leg rest assembly  10  may also include a securing member or lock  90 , which engages with the lever  20 . In the embodiment shown in  FIG. 6 , the securing member  90  has a hook like shape and is attached to the lower portion  28  of the hanger portion  18  by a fastener  92 . The securing member  90  of the embodiment shown in  FIG. 6  is adapted to pivot between a first position in which it is engaged with the lever  20 , as shown in  FIG. 6 , and a second position in which it is disengaged from the lever  20 , as shown in  FIG. 7 . When the securing member  90  is engaged with the lever  20 , it secures the lever in place and prevents the lever from moving upward or downward. When the lever  20  is thus secured, the pivoting member  16  is prevented from moving in both the first or upward direction and the second or downward direction. Accordingly, once a user has moved the elevating member  14  of the leg rest assembly  10  to its desired height, the user may then engage the securing member  90  with the lever  20  to prevent any subsequent movement of the elevating member  14 . The securing member  90  also prevents any accidental disengagement of the lever  20 , thus preventing undesired movement of the elevating member  14 . This securing member  90  need not be included with all embodiments of leg rest assembly  10 .  
      Referring once again to  FIG. 6 , the leg rest assembly  10  may include a leg pad  94  for the support of a user&#39;s leg. The leg pad shown in the embodiment in  FIG. 6  includes an attachment frame  96  which is mounted to the tube  60  of the elevating member  14 . The attachment frame  96  is adapted to be moved along the tube  60  to allow the location of the leg pad  94  to be chosen by the user according to comfort ability and support. In the embodiment shown in  FIG. 6 , the leg pad  94  is mounted to the attachment frame  96  by support bracket  98  and fastener  100 . This arrangement allows the leg pad  94  to also be rotated with respect of the attachment frame  96  to adjust the leg pad according to the user&#39;s preference. The leg rest assembly  10  could include various combinations and numbers of leg pads  94  and leg rest platforms  70 . In addition, the shape and configuration of both the leg pad  94  and leg rest platform  70  could vary greatly and they could be attached to the leg rest assembly in various ways.  
      Finally, it will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention, which is not to be considered limited to what is described in the specification.