The present invention relates to the field of wheelchairs. More particularly, the present invention relates to wheelchairs capable of being utilized in multi-terrains outdoors and indoors.
Typical wheelchairs have two large diameter rear driving wheels positioned beneath the seat portion of the chair and smaller diameter pivoting castor wheels (four to eight inches in size) positioned in front of the rear wheels. However, the problem with these current wheelchairs is that the smaller castors provide reduced stability and are not usable off-road. Problems encountered by a user attempting to utilize a typical wheelchair off-road include: instability caused by a high center of gravity, causing the wheelchair to topple backwards or sideways when negotiating steep grades; the wheels becoming stuck while traversing uneven surfaces; and/or the wheelchair is unable to traverse over objects in its path due to instability or inadequate clearance. Further, if the wheelchair is configured to have more clearance, a user's legs will not fit under tables.
To address the uphill stability/tipping concerns, some wheelchairs are equipped with anti-tippers. Anti-tippers are additional little wheels designed to prevent a wheelchair from tipping over backward. But anti-tippers restrict a wheelchair's ability to go over obstacles because they can get caught on the obstacle. In addition, adjusting, engaging, or disengaging the anti-tippers is extremely difficult for a seated wheelchair user because the anti-tippers can not be reached easily by the user.
Even when utilizing sport model wheelchair types (i.e., where the chair is configured such that the user's knees are bent upward and the feet rest nearly in the same plane as the buttocks), a wheelchair user is faced with similar problems when attempting to traverse off-road and in a steep incline situation.
A multi-terrain wheelchair is disclosed. This multi-terrain wheelchair is a lightweight, manually powered wheelchair that allows a user to easily traverse dirt roads, ruts, trails, rough ground, and similar hindrances, and still be usable indoors. The preferred embodiment of the present invention is configured with two driving wheels in the front where the user has more power, and a single large diameter castor wheel in the back. The single, large diameter castor wheel in the back provides for stability when the multi-terrain wheelchair is used up an incline (e.g., uphill). The two front driving wheels are configured to allow enough room for a user's feet, yet still permit the multi-terrain wheelchair to traverse obstacles. In addition, the large front driving wheels are configured such that they do not dig into gravel and soft dirt in order to allow for easier travel over gravel and soft dirt.
The preferred embodiment of the current invention folds into a compact package for stowing and enables all wheels to stay on the ground when riding or while on uneven surfaces. Further, preferably the multi-terrain wheelchair is configured such that it can be folded and stowed with no need to remove parts.
Specifically, the multi-terrain wheelchair preferably comprises a foldable frame configured for carrying a user in a seated position. In the preferred embodiment, the frame further comprises a plurality of hinges configured to allow the frame to fold. In alternative embodiments, the frame is not foldable. Further, the multi-terrain wheelchair comprises a pair of front driving wheels that are rotatably mounted on the front portion of the foldable frame and a single rear castor wheel that is rotatably mounted on the rear portion of the foldable frame. Preferably, when the frame is folded, the driving wheels and the castor wheel are aligned in substantially the same plane. The frame preferably comprises a lightweight metal. For example, in one embodiment, the frame comprises a lightweight polymer.
The diameter of the single rear castor has a much larger diameter than castor wheels in existing wheelchairs. The castor wheel disclosed is positioned on the rear portion of the rear foldable frame and in between the two driving wheels. In one embodiment of the current invention, the castor wheel is approximately ¼ less than the diameter of the pair of front driving wheels. It should be understood that the diameters of the pair of front driving wheels are equal.
Preferably, the pair of front driving wheels and the single rear castor wheel are aligned in substantially the same plane once the foldable frame is folded. In other embodiments, the pair of front driving wheels and the single rear castor wheel are not aligned in substantially the same plane once the foldable frame is folded, but are slightly offset. In yet other embodiments, the pair of front driving wheels fold upward and the single rear castor wheel folds downward such that the wheels are aligned in substantially stacked configuration once the foldable frame is folded. In alternative embodiments, the multi-terrain wheelchair further comprises a plurality of shock-absorbers configured to couple with the frame, the driving wheels, and the castor wheel.
The driving wheels are preferably in a rotatably mounted configuration and are configured to engage multi-terrain types. The driving wheels are coupled to the frame and are positioned on the frontward portion of the frame. Further, the castor wheel is preferably configured to also engage multi-terrain types and is coupled to the frame and positioned on the rearward portion of the frame. As state above, the preferred castor wheel is parallel to and positioned rearwardly to and between the driving wheels.
In alternative embodiments, the multi-terrain wheelchair comprises a foldable frame comprising at least one driving wheel connector. The driving wheel connector is positioned on the frontward portion of the frame. Further, the foldable frame comprises at least one castor connector that is positioned on the rearward portion of the frame. In addition, this alternative embodiment comprises two driving wheels each separately coupled to the driving wheel connector. Also, the multi-terrain wheelchair comprises one rotatably mounted castor coupled to the castor connector.
In another embodiment, a tri-wheeled multi-terrain wheelchair is disclosed. The wheelchair comprises a foldable frame. The foldable frame comprises a front portion, a rear portion, a top portion, a bottom portion, a first side, and a second side. The tri-wheeled wheelchair further comprises a first driving wheel coupled to the first side of the foldable frame. The first driving wheel is positioned on the front portion of the foldable frame. Also, the tri-wheeled wheelchair comprises a second driving wheel coupled to the second side of the foldable frame. This second driving wheel is positioned directly across from the first driving wheel and on the front portion of the foldable frame. Further, a castor wheel is coupled to the rear portion of the foldable frame. This castor wheel is positioned between the first and the second driving wheel. Finally, a seat is coupled to the top portion of the foldable frame and positioned between the first and second driving wheel and approximately on the front portion of the foldable frame.
Another embodiment of the multi-terrain foldable wheelchair comprises a foldable frame. This foldable frame comprises a backrest and a seat. The foldable frame is in a tubular configuration in one embodiment. In alternative embodiments, the foldable frame further comprises an axle. The axle comprises a quick release connection configured to allow the driving wheels and the castor wheel to detachably couple with the frame.
This alternative embodiment further comprises a pair of driving wheels coupled to the frame and positioned on the frontward portion of the frame. The driving wheels each comprise a hub. In alternative embodiments, the driving wheels each comprise a hand rim and a plurality of spokes.
A castor wheel comprising a hub is coupled to the frame and is positioned between the pair of driving wheels on the rearward portion of the frame. In alternative embodiments, the castor wheel further comprises a hand rim and a plurality of spokes.
Further, this embodiment of the wheelchair comprises a brake coupled to the frame. The brake is configured to stop movement of the driving wheels and the castor wheel. The brake comprises a mechanical lever system in an embodiment.
In this embodiment, a castor housing is also present. The castor housing is coupled to the frame and the castor wheel. The castor housing is configured to allow the castor wheel to spin (e.g., rotate 360 degrees).
This wheelchair further comprises a pair of swing away foot rests configured to serve as a platform on which a user's feet may be supported. The pair of swing away foot rests are coupled to the frame and are configured to rotate outwardly. Finally, in alternative embodiments, the multi-terrain foldable wheelchair further comprises a plurality of shock-absorbers configured to couple with the frame, the driving wheels, and the castor wheel.
In addition to the wheelchair embodiments disclosed above, a method of fabricating a multi-terrain wheelchair is disclosed. Specifically, the method of fabricating comprises first fabricating a frame configured to fold. Next, a first driving wheel with a first diameter is fabricated. Then, a second driving wheel with a diameter equal to the first diameter is fabricated. A castor wheel with a second diameter is next fabricated. The first driving wheel is positioned approximately on the front of the frame and coupled to the frame. Next, the second driving wheel is positioned directly across from the first driving wheel and approximately on the front of the frame and is coupled to the frame. Finally, the castor wheel is positioned between the first and the second driving wheels and coupled to the rear of the foldable frame.
A multi-terrain wheelchair 100 is disclosed. The multi-terrain wheelchair 100 is a lightweight, manually powered wheelchair that allows a user to easily traverse dirt roads, ruts, trails, rough ground, and similar hindrances, and still be usable indoors. The preferred embodiment of the present invention is configured with two driving wheels in the front where the user has more power, and a single large diameter wheel castor in the rear.
In the preferred embodiment, the first and the second driving wheels 104 and the castor wheel 106 of the multi-terrain wheelchair 100 are aligned in substantially the same plane once the frame 102 is folded. In another embodiment (not shown), the first and the second driving wheels 104 and the castor wheel 106 are not aligned in substantially the same plane once the frame 102 is folded. In yet other embodiments (not shown), the first and the second driving wheels 104 fold upward and the castor wheel 106 folds downward such that the first and the second driving wheels 104 and the castor wheel 106 are aligned in substantially stacked configuration once the foldable frame is folded.
The two front driving wheels 104 each have a first diameter, and the one rear castor wheel 106 has a second diameter, wherein the second diameter is smaller than the first diameter. Preferably, the second diameter of the single rear castor wheel 106 is approximately ¼ less than the first diameter of the pair of front driving wheels 104.
In alternative embodiments, the multi-terrain wheelchair 100 further comprises a plurality of shock-absorbers 130 configured to couple with the frame 102, the driving wheels 104, and castor wheel 106.
In yet another embodiment, the multi-terrain wheelchair 100 comprises a plurality of rotatably mounted driving wheels (not shown) similar to the driving wheels 104, that are configured to engage multi-terrains and coupled to and positioned on the frontward portion of the frame 102. In this alternative embodiment (not shown), the wheelchair 100 further comprises at least one rotatably mounted castor wheel, similar to the castor wheel 106, that is configured to engage multi-terrains and is coupled to and positioned on the rearward portion of the frame 102. This at least one rotatably mounted castor wheel is parallel to and positioned rearwardly to and between the plurality of driving wheels 104.
Although the preferred multi-terrain wheelchair 100 of the present invention comprises one castor wheel connector otherwise referred to as a castor wheel coupler, on the rearward portion of the frame 102 and a pair of driving wheels 104 on the frontward portion of the frame 102, it should be understood that in alternative embodiments, the multi-terrain wheelchair 100 includes at least one driving wheel connector or driver wheel coupler 112 positioned on the frontward portion of the frame 102 and at least one castor connector or castor wheel coupler 110 positioned on the rearward portion of the frame 102. In this alternative embodiment, the wheelchair 100 comprises two driving wheels 104 each separately coupled to the at least one driving wheel connector or driver wheel coupler 112 and one rotatably mounted castor wheel 106 coupled to the at least one castor connector or castor wheel coupler 110.
In yet another embodiment, the multi-terrain wheelchair 100 is in a tri-wheeled configuration and comprises a foldable frame 102 comprising a front portion, a rear portion, a top portion, a bottom portion, a first side, and a second side. A first driving wheel is coupled to the first side of the foldable frame 102. This first driving wheel is positioned on the front portion of the foldable frame 102. A second driving wheel is coupled to the second side of the foldable frame 102 and is positioned directly across from the first driving wheel and on the front portion of the foldable frame 102. The tri-wheeled wheelchair 100 further comprises a castor wheel 106 coupled to the rear portion of the foldable frame 102. The castor wheel 106 is positioned between the first and the second driving wheel. Finally, the tri-wheeled wheelchair 100 comprises a seat and a backrest 108 coupled to the top portion of the foldable frame 102 and positioned between the first and second driving wheel and approximately on the front portion of the foldable frame 102. Further, as with the other embodiments, the first and the second driving wheels 104 each have a first diameter, and the castor wheel 106 has a second diameter, wherein the second diameter is smaller than the first diameter, and is preferably approximately ¼ less than the first diameter.
In other embodiments of the multi-terrain foldable wheelchair 100, a pair of driving wheels 104 each comprising a driving wheel hub 104′ (
In alternative embodiments, a pair of driver wheel housings (not shown) configured to allow the pair of the driver wheels to spin (e.g., rotate 360 degrees) are coupled to the frame 102 and separately coupled to each of the pair of driver wheels. Similarly, a castor wheel housing (not shown) configured to allow the castor wheel 106 to spin (e.g., rotate 360 degrees) is coupled to the frame 102 and the castor wheel 106. Finally, a pair of swing away foot rests 142 configured to serve as a platform on which feet may be supported are coupled to the frame 102 and are configured to rotated outwardly.
The frame 102 is preferably foldable and in a tubular configuration. In alternative embodiments, the frame 102 further comprises an axle (not shown) configured to couple to the driving wheels 104 and/or the castor wheel 106. The axle (not shown) alternatively comprises a quick release connection 136 configured to allow the driving wheels 104 and the castor wheel 106 to detachably couple with the frame 102.
The pair of driving wheels 104 and the castor wheel 106, in alternative embodiments, further each comprise a hand rim 132 and a plurality of spokes 134.
In addition to the multi-terrain wheelchair itself, a method of fabricating a multi-terrain wheelchair is also disclosed. The method first comprises fabricating a frame configured to fold. The method next comprises fabricating a first driving wheel with a first diameter and then fabricating a second driving wheel with the first diameter. Next, a castor wheel with a second diameter is fabricated. The first driving wheel is next positioned approximately on the front of the frame and coupled to the frame. Next, the second driving wheel is positioned directly across from the first driving wheel and approximately on the front of the frame and coupled to the frame. Finally, the castor wheel is positioned between the first and the second driving wheels and coupled to the rear of the foldable frame. Preferably, the first diameter is approximately ¼ larger than the second diameter. In an alternative embodiments of this method the frame comprises a lightweight metal, a lightweight polymer, or combination.
The multi-terrain wheelchair currently disclosed provides an improved multi-terrain wheelchair that may be utilized on a wide range of terrains. Further, the current invention provides for increased stability and mobility at a reduced cost and without cumbersome, heavy, or unaesthetic parts. In short, the current multi-terrain wheelchair provides an economically, aesthetically, and socially improved wheelchair allowing users to do and see things that were previously unavailable due to limitations in existing wheelchairs which hinder multi-terrain mobility.
The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of the principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be apparent to one of ordinary skill in the art that the device of the present invention could be implemented in several different ways and the embodiments disclosed above are only exemplary of the preferred embodiment and the alternative embodiments of the invention and is in no way a limitation. It will be apparent to those skilled in the art that modifications may be made in the embodiment chosen for illustration without departing from the spirit and scope of the invention.
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