BACKGROUND OF THE INVENTION
Pestes, U.S. Pat. No. 6,645,127, discloses a wheelchair exercise apparatus in which a wheelchair is driven up a ramp onto a platform. A pair of side by side rollers, which extend above the platform, support the wheelchair driving wheels. A clamp mechanism holds the wheelchair immovably on the rollers. The rollers are connected to a flywheel which provides the momentum associated with actual wheelchair operation. One difficulty with this prior art apparatus is that elderly people or people who are new to using a wheelchair may have limited arm strength and overcoming the resistance caused by driving two rollers for an extended period of time may not be possible for them. However, it is very difficult to drive the driving wheels of a wheelchair up onto a single roller and lock it in place with the driving wheels centered on the roller.
SUMMARY OF THE INVENTION
The subject invention overcomes the problem with the prior art by providing a wheelchair exercise device having a platform that will support a wheel chair with an elongate slot extending across the platform substantially normal to the plane of the driving wheels of the wheelchair. An elongate roller is movable between a lowered position where it is substantially below the platform and a raised position where it projects through the slot and extends partially above the platform. The axis of the roller is directly below the center line of the slot so that when the driving wheels of the wheelchair are positioned in the slot they are centered above the roller. A locking mechanism holds the wheelchair in place once it is positioned in the slot. The roller is then moved to its raised position where it supports the driving wheels.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS
FIG. 1 is a prospective view of a wheelchair exercise apparatus embodying the subject invention.
FIG. 2 is a fore-shortened side elevation view of the apparatus of FIG. 1 with a wheelchair in place.
FIGS. 3 and 4 are side elevation views, partially broken away to show a hidden portion of the apparatus.
FIG. 5 is a side elevation view, at a larger scale, showing a clamp which is a feature of the subject invention.
FIG. 6 is a prospective view showing a locking mechanism which is a feature of the subject invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2 of the drawings, a wheelchair exercise apparatus 10 includes a raised platform 12 and a ramp 14 which allows a wheelchair 13 to be driven up onto the platform, The platform is supported by a rigid frame 16. A slot 18 is located in the platform 12 close to where the platform joins the ramp 14. The slot is generally perpendicular to the planes of the larger diameter driving wheels 20 of the wheelchair when the wheelchair is driven onto the platform. The slot has a width which the driving wheels can bridge and yet the bottoms of the driving wheels will drop slightly into the slot, FIG. 4. This essentially centers the driving wheels 20 over the center line of the slot 18.
Referring now also to FIGS. 3 and 4, an elongate roller 22 has an axis which is parallel to the center line of the slot 18 and is located vertically below the center line of the slot. The roller 22 is journald at each of its ends in bearings 24 which are mounted on rocker plates 26. The rocker plates 26 are rotatable mounted on posts 28 which are mounted on the frame 16. The rocker plates are rotatably between a first position, FIG. 4, where the roller is in a lowered position substantially below the upper surface of the platform 12, and a second position, FIG. 3, where the roller is in a raised position where it projects through the slot 18 and extends slightly above the upper surface of the platform 12. The rocker plates are connected to one another by tie bars 30 so that they rotate together. A linear actuator 32 has one end 34 which is rotatably attached to a clevis 36 mounted on the frame. An extensible piston 38 is located at the other end 40 of the actuator. The piston 38 is movable between a retracted position, FIG. 4, where the rockcr plate 26 places the roller is in its lowered position, and an extended position, FIG. 5, where the rocker plate places the roller is in its raised position. While any type of linear actuator could be used, a rack and pinion actuator powered by an electric motor 40 works well for this purpose. The roller 22 is connected to a flywheel 42 through a pulley system 44. The flywheel simulates the movement that a wheelchair would experience in a normal rolling operation. It also allows additional resistance to be provided to the roller 22. While there are many ways this resistance could be applied, in the preferred embodiment illustrated resistance is applied by means of a magnetic brake 46 located on the flywheel which allow precisely applying the desired amount of resistance.
A support tower 48 extends upwardly from the frame 16 forward of the slot 18. In the embodiment illustrated the flywheel 42 is mounted on the support tower but it could be mounted elsewhere if desired. The support tower also carries a locking mechanism 50 which is used to prevent the wheelchair from moving when the roller is being moved to its raised position and when the wheelchair is being driven on the roller 22. Referring now also to FIGS. 5 and 6, the locking mechanism includes a pair of quick release clamps 52 which can be clamped to a desired component 54 of the wheelchair. A lever 56 operates a cam 58 to move a movable jaw 60 of the clamp relative to a fixed jaw 62 to provide the clamping action. A mounting rod 64 extends between the two legs 66 of the support tower 48. Mounted slidably and rotatably on the mounting rod 64 is a pair of first blocks 68, one for each clamp 52. Outriggers 70 mounted on each side of each first block allow the first blocks to rotate and slide on the mounting rod without binding. A second block 72 is mounted on each first block 68. The second blocks slidably carry clamp rods 74 which are perpendicular with the mounting rod 64. One of the clamps 52 is mounted on the extremity of each clamp rod 74. A lock (not shown) allows the clamp rods 74 to be locked in place in the second blocks. With the locks on the second blocks unlocked each set of first and second blocks 68, 72 can be rotated or slid sideways along the mounting rod 64, and the clamp rod 74 can be slid in and out of the second block 72. This gives the user complete freedom to attach the clamps 52 to a desired component 54 of the wheelchair 13. However, when the clamps 52 are attached and the locks on the second blocks 72 are locked, the entire locking mechanism becomes rigid and holds the wheelchair firmly in place.
If desired a control panel 76 can be mounted on the support tower 48. A sensor 78, which senses the rotational speed of the roller, is connected to the control panel to provide the user with a readout of the speed the wheelchair is simulating. The control panel 76 can also be used to start and stop the motor 40 and to move the roller between its lowered and raised positions. The control panel also can be used to control the brake 46 to set and see the level of resistance. Finally, the control panel can provide performance data, such as the elapsed time of an ongoing exercise and the user's heart rate.
In use with the roller 22 in its lowered position the wheelchair 13 is propelled up the ramp 14 onto the platform 12 with the driving wheels 20 positioned in the slot 18. The two clamps 52 are then attached to a suitable component 54 of the wheelchair and the locks on the second blocks 72 are locked. The roller 22 is then moved to its raised position and the exercise apparatus is ready to be used. Once in operation the user can increase or decrease the drag on the roller by manipulating the brake 46 on the flywheel 42.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
Patent Application
20110015045
