WO2001032119A1

WO2001032119A1 - Axle plate for a wheelchair

Info

Publication number: WO2001032119A1
Application number: PCT/US2000/029793
Authority: WO
Inventors: Rex W. Stevens; Joshua J. Heit
Original assignee: Sunrise Medical Hhg Inc.
Priority date: 1999-10-29
Filing date: 2000-10-27
Publication date: 2001-05-10
Also published as: AU1243401A

Abstract

An axle bracket provides a mounting for the drive wheel of a wheelchair to a wheelchair frame. The wheelchair frame includes an upper side frame member and a rear vertical frame member. The axle bracket comprises left and right axle plates, each of which is adapted to be mounted to both the upper side frame member and the rear vertical frame member of the wheelchair frame. The plates have a series of axle orifices through which a wheel axle can be extended. The axle orifices of the left plate are coaxial with the corresponding axle orifices of the right plate when the axle bracket is mounted on the wheelchair frame.

Description

AXLE PLATE FOR A WHEELCHAIR

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

This invention relates to the arrangement of structural members used on wheelchairs. More particularly, this invention pertains to wheelchair structural members that are capable of mounting the axles for the rear drive wheels of manual wheelchairs.

BACKGROUND OF THE INVENTION Wheelchairs are well known forms of transportation that increase the mobility of the physically impaired. Wheelchairs are typically relatively small, single-person conveyances that generally comprise a seat supported by a frame which, in turn, is supported by two opposed drive wheels and two front casters. The drive wheels for a manual wheelchair are typically mounted for rotation on axles, with the axles usually being mounted either though the frame members or through an axle plate secured to the wheelchair frame. The axles themselves are often specially made quick release axles that allow easy removal of the drive wheels from the wheelchair. Some wheelchairs, particularly low cost models, use a simple bolt for the axle of the drive wheel. Where the axle is mounted directly through the frame tube, the maximum hole that can be drilled is about 7/16 inches in diameter. This is an acceptable size for the situation where a bolt is used as the axle. However, quick release axles have a diameter of about ^lA inches, and therefore quick release axles cannot be mounted directly through the wheelchair frame tube unless the quick release axles are modified. One of the important features provided in some wheelchairs is the ability to adjust the position of the wheelchair axle with respect to the wheelchair frame. Preferably, the axle can be moved among several different height adjustments to accommodate the needs of the wheelchair user, and ideally, the axle can be moved forwardly or rearwardly as well.

Wheelchair frames for manual wheelchairs usually are comprised of left and right side frame, and cross frames, which may include a folding mechanism. The side frames typically include upper and lower side frames that extend horizontally, and forward and rear vertical frames. These various frame members are welded together to make up the entire side frame. It has been determined that the weakest link in the construction of these frames is usually the welded joint between the horizontally extending upper side frame and the rear vertical frame.

One of the common accessories used on wheelchairs is an arm rest. While an armrest is helpful the wheelchair user while the wheelchair user is positioned in the wheelchair, the armrest can be in the way at the time when the user is getting into or out of the wheelchair. Therefore, arm rests are often mounted with a swing away feature that allows the armrest to be easily moved to allow easier access and egress to and from the wheelchair.

It would be advantageous if there could be developed a wheelchair axle supporting system that was simple in design for easy and low cost manufacturing, and yet provided some adjustability for different desired heights of the axle with respect to the ground.

SUMMARY OF THE INVENTION The above objects as well as other objects not specifically enumerated are achieved by an axle bracket for mounting the drive wheel of a wheelchair to a wheelchair frame, where the wheelchair frame includes an upper side frame member and a rear vertical frame member. The axle bracket comprises left and right axle plates, each of which is adapted to be mounted to both the upper side frame member and the rear vertical frame member of the wheelchair frame. The plates have a series of axle orifices through which a wheel axle can be extended. The axle orifices of the left plate are coaxial with the corresponding axle orifices of the right plate when the axle bracket is mounted on the wheelchair frame. In another embodiment of the invention, there is provided a wheelchair having a frame, two drive wheels mounted on axles, two caster wheels, and a seat. The frame has left and right side frames, each of which includes an upper side frame member, a lower side frame member, a forward vertical frame member, and a rear vertical frame member. An axle bracket is mounted on the frame, the axle bracket comprising left and right axle plates, each of which is mounted to both the upper side frame member and the rear vertical frame member of the wheelchair frame. The plates have a series of axle orifices through which the axle of a drive wheel is extended, with the axle orifices of the left plate being coaxial with the corresponding axle orifices of the right plate. In yet another embodiment of the invention, there is provided a wheelchair having a frame, where the frame has left and right side frames, each of which includes an upper side frame member and a rear vertical frame member that are welded to each other. An axle bracket is mounted on both the upper side frame member and a rear vertical frame member. The axle bracket provides a mounting for an axle of a wheelchair drive wheel, and the axle bracket strengthens the connection between the upper side frame member and the rear vertical frame member.

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 DRAWINGS

Figure 1 is a schematic view in elevation of a wheelchair including the axle bracket of the invention.

Figure 2 is schematic exploded view in perspective of the axle bracket and a portion of the frame of the wheelchair shown in Figure 1.

Figure 3 is an enlarged view in elevation of the axle bracket and a portion of the frame of the wheelchair.

Figure 4 is a schematic view in perspective of the arm saddle flipback bracket mounted on the upper side frame member.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION As shown in Figure 1, a wheelchair is generally indicated at 10. The wheelchair includes a frame, generally indicated at 12, two drive wheels 14 (shown partially cut away), and two front casters 16. The wheelchair is adapted to accept a seat and a seatback, both of which are not shown. It is to be understood that numerous configurations of the frame and wheels can be used with the invention. The frame 12 includes two side frames 18, one on each of the left and right sides of the wheelchair. Each side frame 18 includes an upper side frame member 20, a lower side frame member 22, a forward vertical frame member 24, and a rear vertical frame member 26. The various side frame members 20, 22, 24, and 26) are welded together, with the welds being indicated at 30.

The wheelchair 10 includes an axle bracket 34 that is mounted to both the upper side frame member 20 and the rear vertical frame member 26. The axle bracket 34 has an axle 36 extending through it. Mounted on the rearward end of the axle bracket 34 is an arm rest tube 38. The arm rest tube extends upwardly from axle bracket 34, then extends horizontally (forwardly) to provide support for the armrest 40, and then extends downwardly toward the upper side frame member 20. A rear saddle 42, and an arm saddle flip back bracket 44 are mounted on the upper side frame member 20 to receive the seat rail of a seat, both not shown. An armrest panel 46 is also mounted on the armrest tube 38. As shown in Figure 2, the axle bracket 34 is comprised of right and left axle plates 50 and 52, respectively. The axle plates are mounted on the upper side frame member 20 and the rear vertical frame member 26, with a spacer 54 positioned between them. The axle plates, 50, 52 have generally planar surfaces, and are preferably made of a stiff plastic material, although other materials can be used. The axle plates include a rear stub that extends rearwardly of the rear vertical frame member 26. The rear stub 56 contains the arm rest hinge point 58, about which the arm rest 40 and arm rest tube 38 can pivot to move the arm rest out of the way so that the wheelchair user can have access to the wheelchair.

The axle plates 50, 52 include a series of axle orifices 62 through which the drive wheel axle 36 can be extended. It can be appreciated that the axle orifices 62 of the left axle plate 52 are coaxial with the corresponding axle orifices 62 of the right plate 50 when the axle bracket 34 is mounted on the wheelchair side frame 18. The axle plates 50, 52 also include bolt orifices 64, with two bolt orifices 64 extending generally parallel to the upper side frame member 20 and two bolt orifices 64 extending generally parallel to the rear vertical frame member 26.

As shown in Figure 3, an arm receiver bracket 66 mounted at the rear stub 56 acts as the pivoting member to enable the arm rest tube 38 to pivot. A pivot bolt 68 is applied to the arm rest hinge point in the rear stub 58. The arm receiver bracket 66 can be provided with a rear knuckle 70 that limits the pivoting of the arm rest 40 when the knuckle contacts the rear vertical frame member 26.

Two axle plate bolts 74 extend through the axle plates 50, 52 and the upper side frame member 20. Also, two axle plate bolts 74 extend through the axle plates 50, 52 and the rear vertical frame member 26. It can be seen from figures 2 and 3 that the axle bracket 34 contains two bolt orifices 62 and bolts 74 extending generally parallel to the upper side frame member 20, and also contains and two bolt orifices 62 and bolts 74 extending generally parallel to the rear vertical frame member 74. It is to be understood that fewer than or less than two bolt orifices 62 and bolts 74 can be used. Also, it can be seen from figure 3 that the bracket plates 50, 52 contain at least two axle orifices 62 arranged generally in parallel with the rear vertical frame member 26. As shown in Figure 4, the arm saddle flip back bracket 44 is adapted to receive the lower end 76 of the arm rest tube 38. A latch 78 is provided on the lower end 76, and pivoting of the latch 78 on mounting bolt 80 engages or releases the arm rest tube with respect to the arm saddle flip back bracket 44, and consequently from the upper side frame member 20. The arm saddle flip back bracket also includes a front saddle 82 for receiving a seat rail, not shown.

Some wheelchairs, particularly low cost models, use a simple bolt for the axle of the drive wheel. Where the axle is mounted directly through the frame tube, the maximum hole that can be drilled is about 7/16 inches in diameter. This is an acceptable size for the situation where a bolt is used as the axle. However, quick release axles have a diameter of about ^XA inches, and therefore quick release axles cannot be mounted directly through the wheelchair frame tube unless the quick release axles are modified.

One of the advantages of the axle bracket of the invention is the ability to adjust the position of the wheelchair axle 36 with respect to the wheelchair frame 12, using the series of axle orifices 62. The axle can be moved among several different height adjustments to accommodate the needs of the wheelchair user. Another advantage of the invention is that the weakest link in the frame system, which is the welded connection between the horizontally extending upper side frame member 20 and the rear vertical frame member 26, is now reinforced with the axle bracket 34. Therefore, problems due to failure of this welded connection are reduced or eliminated. Another advantage of the invention is that the armrest 40 can be easily moved to allow easier access and egress to and from the wheelchair. Yet another advantage of the invention is that by using an axle bracket that eliminates the need for extending the axle through any of the frame members, the axle bracket 34 and spacer 54 can be adapted to receive not only a standard quick release axle, but also a common, off the shelf, bolt. This provides a manufacturing cost advantage because of the low cost of the common bolt. Further, by combining the functions of supporting the axle with height adjustability, and mounting the swing away armrest, the overall cost of manufacturing the wheelchair can be reduced.

The principle and mode of operation of this invention have been described in its preferred embodiments. However, it should be noted that this invention may be practiced otherwise than as specifically illustrated and described without departing from its scope.

Claims

What is claimed is:

1. An axle bracket for mounting the drive wheel of a wheelchair to a wheelchair frame, the wheelchair frame including an upper side frame member and a rear vertical frame member, the axle bracket comprising left and right axle plates, each of which is adapted to be mounted to both the upper side frame member and the rear vertical frame member of the wheelchair frame, the plates having a series of axle orifices through which a wheel axle can be extended, with the axle orifices of the left plate being coaxial with the corresponding axle orifices of the right plate when the axle bracket is mounted on the wheelchair frame.

2. The axle bracket of claim 1 in which the axle bracket includes a rear stub that extends rearwardly of the rear vertical frame member when the axle bracket is mounted on the wheelchair frame, the rear stub including a pivot point for pivotally mounting a wheelchair armrest on the wheelchair.

3. The axle bracket of claim 1 in which the axle bracket contains at least two axle orifices arranged generally in parallel with the rear vertical frame member.

4. The axle bracket of claim 1 in which the axle bracket contains two bolt orifices extending generally parallel to the upper side frame member and two bolt orifices extending generally parallel to the rear vertical frame member.

5. The axle bracket of claim 1 in which the axle bracket contains at least two axle orifices arranged generally in parallel with the rear vertical frame member, and in which the axle bracket contains two bolt orifices extending generally parallel to the upper side frame member and two bolt orifices extending generally parallel to the rear vertical frame member.

6. A wheelchair having a frame, two drive wheels mounted on axles, two caster wheels, and a seat, the frame having left and right side frames, each of which includes an upper side frame member, a lower side frame member, a forward vertical frame member, and a rear vertical frame member, and an axle bracket mounted on the frame, the axle bracket comprising left and right axle plates, each of which is mounted to both the upper side frame member and the rear vertical frame member of the wheelchair frame, the plates having a series of axle orifices through which the axle of a drive wheel is extended, with the axle orifices of the left plate being coaxial with the corresponding axle orifices of the right plate.

7. The axle bracket of claim 6 in which the axle bracket includes a rear stub that extends rearwardly of the rear vertical frame member, the rear stub including a pivot point for pivotally mounting a wheelchair armrest on the wheelchair.

8. The axle bracket of claim 6 in which the axle bracket contains at least two axle orifices arranged generally in parallel with the rear vertical frame member.

9. The axle bracket of claim 6 in which the axle bracket is bolted to the upper side frame member with two bolts extending through the upper side frame member and arranged generally parallel to the upper side frame member, and in which the axle bracket is bolted to the rear vertical frame member with two bolts extending through the rear vertical frame member and arranged generally parallel to the rear vertical frame member.

10. A wheelchair having a frame, the frame having left and right side frames, each of which includes an upper side frame member and a rear vertical frame member that are welded to each other, and further including an axle bracket mounted on both the upper side frame member and a rear vertical frame member, the axle bracket providing a mounting for an axle of a wheelchair drive wheel, wherein the axle bracket strengthens the connection between the upper side frame member and the rear vertical frame member.

11. The wheelchair of claim 10 in which the axle bracket comprises left and right axle plates, each of which is mounted to both the upper side frame member and the rear vertical frame member of the wheelchair frame, the plates having a series of axle orifices through which the axle of a drive wheel is extended, with the axle orifices of the left plate being coaxial with the corresponding axle orifices of the right plate.

12. The axle bracket of claim 10 in which the axle bracket includes a rear stub that extends rearwardly of the rear vertical frame member, the rear stub including a pivot point for pivotally mounting a wheelchair armrest on the wheelchair.

13. The axle bracket of claim 10 in which the axle bracket contains at least two axle orifices arranged generally in parallel with the rear vertical frame member.

14. The axle bracket of claim 10 in which the axle bracket is bolted to the upper side frame member with two bolts extending through the upper side frame member and arranged generally parallel to the upper side frame member, and in which the axle bracket is bolted to the rear vertical frame member with two bolts extending through the rear vertical frame member and arranged generally parallel to the rear vertical frame member.