Motor vehicles – Special driving device – Portable track
Reexamination Certificate
1999-09-01
2001-06-26
Hurley, Kevin (Department: 3611)
Motor vehicles
Special driving device
Portable track
C180S006500, C180S006540
Reexamination Certificate
active
06250409
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention is intended to alleviate some of problems that are inherent in apparatus used to provide mobility for disabled persons. However, this device would be useful in many situations where transport is desired over rough terrain. This device is useful in the transportation of both persons and/or items across rough or smooth terrain, both outdoors and in an indoor situation. An analogous tool used by disabled or handicapped persons is a wheelchair, while an analogous load carrying device is commonly known as a skid-steer loader. Both items transport items and persons, yet neither one is able to be integrated fully in both an outdoor and an indoor setting.
While wheelchairs are the common form of transportation in areas that are prepared to receive these means of conveyance, areas such as nature trails, gravel paths, and crossings having excessive mud or water, generally prove to be insurmountable obstacles for the average wheelchair. In these more primitive conditions, wheels tend to find surface imperfections, such as rocks, to be barriers that are not readily rolled over. In situations where mud, sand, or snow are present, wheels will often sink into the mud, sand, or snow, causing the wheelchair to become mired and easily stuck.
The use of belts, placed over a series of wheels, in the form of a track assembly, will usually be able to traverse over the primitive areas that would generally restrict movement of a typical wheelchair. The multi-use capability of a belted track assembly is readily apparent in construction equipment as well as military vehicles. Small vehicles, such as a typical skid-steer loaders have significant mobility, through the use of controlling the speed and/or the direction of movement for each of the tracks.
While belted track assemblies provide significant advantages over wheels in rough terrain situations, such a means of conveyance prove utterly destructive to typical household surfaces, such as carpeting and many types of household flooring. The reason for this is that the surface of the track can only go forwards and backwards, which results in significant lateral friction during turning exercises. This causes scraping of smooth flooring, and virtual shredding of many types of carpets.
SUMMARY OF THE INVENTION
This invention provides a frame that supports a seat for the user, as well as the power and drive sources for the invention. This multi-point mobility device is generally electrically powered, finding the source of electrical energy in stored batteries positioned on the frame.
Movement of the multi-point mobility device is accomplished through a set of track assemblies located on each side of the frame, which generally comprise a belt fitted over a rear drive wheel, a larger center wheel, and a front wheel. The front wheel and rear drive wheel are fixed to the frame, accepting some minor adjustments horizontal to the frame and each other, so as to provide the proper amount of tension to the belt.
Each set of track assemblies are independently powered, and controlled by the user/operator of this invention. The center wheel of the track assembly has the capability of being raised or lowered, with respect to the front wheel and rear drive wheel. When the center wheel is raised to its upward position, all three wheels of each track assembly will cause the belt to concurrently contact a flat ground surface. When the center wheel is lowered, the rear drive wheel and front wheel do not present the belt to the ground surface in a straight line with the center wheel. When the center wheel is lowered, only one other wheel at a time in the track assembly is capable of concurrently causing the belt to contact a flat surface the device is resting on.
A rear wheel, independent of either track assembly, is provided at the central rear-most portion of this invention. The rear wheel is capable of being raised off of the ground, or lowered to the ground by an actuating cylinder, to the point where it causes the back end of the device to be raised up off of the ground surface. When the rear wheel is raised off of the ground, the track assemblies will contact the ground according to the position of the center wheel, and the distribution of weight either forward or aft of the track assembly's center wheel when it is in the lowered position.
Using the rear wheel in conjunction with the up and down configuration for the center wheel, provides four basic track configurations, with each track configuration offering its own independent capability over various terrain and turning conditions.
The first configuration is the typical wheel track configuration, where the rear wheel is raised, along with the center wheel. In this configuration, the full-length of the bottom portion of the track will present itself to the ground surface in a linear fashion. This is the configuration typical with most prior track belt assemblies.
The second configuration of the track assembly is where the center wheel is lowered, with the rear wheel remaining in a raised position, with the greater weight distributed behind or aft of the center wheel. This causes that portion of the track in front of the center wheel to be raised off of the ground surface at an angle. One obvious advantage to this configuration is the lessening of the impact and tendency to bog down a track configuration in heavy snow or muddy conditions, as the front part of the track is always presented to the ground surface in an angled climbing position.
The third configuration of track assembly is when the center wheel is lowered, along with the rear wheel. In this configuration, the point of contact with the ground are made by the rear wheel, and by the portion of the track in contiguous contact with the bottom of the track assembly's center wheel. This is a three-point contact with the ground surface, and provides a minimum of contact by the track with the ground surface. This configuration is most useful in a home situation, presenting minimal belt surface against the floor or carpet, which in turn limits the lateral friction area of the belt against the floor or carpet during turning.
The fourth configuration is where the center wheel is raised, so as to provide a straight linear configuration for that portion of the belts adjacent to the ground surface. The rear wheel is urged downward below the horizontal plane of the track on the ground surface, so that the rear wheel causes the back or entire rear portion of the multi-point mobility device frame to be raised upward, in comparison to the front of said device frame. This has the effect of causing the rear portion of the track assemblies to be lifted off of the ground surface, so that the points of contact with the ground surface comprise the rear wheel and front portion of said track assemblies.
This fourth configuration supplies a track configuration which has minimal contact with ground surface, and which in effect pulls the invention around corners. This configuration along with the third configuration described above, provide optimal turning abilities within confined areas, utilizing minimal track contact with floor or ground surfaces.
Further optimization of this invention is realized through the use of sensors and display means, which can indicate to the user the basic track configurations, and the extent to which they are positioned.
This invention is further supplied with a means to engage and disengage the electric drive motors. When so disengaged, the track assemblies can move freely, so that this apparatus can function in a manner similar to the typical wheelchair. This is especially true with the third configuration of the track assemblies described above.
The track assembly belts are able to maintain the stable tension level necessary, through the adjustment of the front wheel in relation to the rear wheel. The center wheel, although larger than either of the other two wheels, does not cause a change in belt tension when moved upward or downward within the parameters established by the invention, since the c
Hurley Kevin
Sylvester Bradley P.
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