Abstract:
An improved wheelchair frame and wheel with a stabilizing wheel frame ( 300 ) supporting a stabilizing wheel ( 320 ) having a protruding stabilizing wheel ridge ( 330 ). The stabilizing wheel frame ( 300 ) affixes to a front frame transverse member ( 380 ) which rotates about a transverse pivot ( 385 ). The rotation of the front frame transverse member ( 380 ) is dampened by attachment to a shock absorber ( 390 ) which is anchored to a shock absorber anchor ( 395 ). Additional stabilization is afforded by a rear stabilizing wheel frame ( 400 ) which supports at least one stabilizing wheel ( 320 ) at the rear ( 7 ) which may have a rear stabilizing wheel ridge ( 330 ).

Description:
FIELD OF THE INVENTION  
       [0001]     The invention is an improvement in the ability to navigate a wheelchair in rough terrain.  
       BACKGROUND OF THE INVENTION  
       [0002]     The operator of a wheelchair will encounter many obstacles to smooth movement. The operation of a standard wheelchair on other that a smooth and hard surface is problematic. Uneven surfaces, pebbles and rocks can inhibit movement. Soft surfaces can trap wheels causing the wheelchair to become stuck.  
       SUMMARY OF THE INVENTION  
       [0003]     This invention comprises a stabilizing wheel frame ( 300 ) supporting a stabilizing wheel ( 320 ) having a protruding stabilizing wheel ridge ( 330 ). The stabilizing wheel frame ( 300 ) affixes to a front frame transverse member ( 380 ) which rotates about a transverse pivot ( 385 ). The rotation of the front frame transverse member ( 380 ) is dampened by attachment to a shock absorber ( 390 ) which is anchored to a shock absorber anchor ( 395 ). Additional stabilization is afforded by a rear stabilizing wheel frame ( 400 ) which supports at least one stabilizing wheel ( 320 ) which may have a rear stabilizing wheel ridge ( 330 ). 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]      FIG. 1  illustrates a wheelchair ( 1 ) with standard configuration for smooth surface travel having a chair frame ( 100 ) and a main frame ( 200 ).  
         [0005]      FIG. 2  illustrates a wheelchair ( 1 ) having a front ( 3 ), a rear ( 7 ), a right side ( 8 ) and a left side ( 9 ); a main frame ( 200 ); a stabilizing wheel frame ( 300 ) with stabilizing frame ( 340 ) having a first end ( 342 ) and a second end ( 344 ); a stabilizing wheel ( 320 ) rotatably received at the first end ( 342 ); the stabilizing wheel frame ( 300 ) fixedly received by the wheelchair ( 1 ) main frame ( 200 ) at the second end ( 344 ).  
         [0006]      FIG. 3  is a cut away from  FIG. 2  illustrating a partial view of the chair frame ( 100 ) and showing the main frame ( 200 ) composed of frame means; a stabilizing wheel frame ( 300 ), at least one front stabilizing frame ( 340 ) having a first end ( 342 ) and a second end ( 344 ); a stabilizing wheel ( 320 ) rotatably received at the first end ( 342 ); the stabilizing wheel frame ( 300 ) fixedly received by the wheelchair ( 1 ) main frame ( 200 ) at the second end ( 344 ); the stabilizing wheel frame ( 300 ) extending outwardly from the wheel chair front ( 3 ); at least one main frame transverse member ( 220 ); at least one front frame extension ( 360 ); at least one transverse pivot ( 385 ); shock absorber means ( 390 ) with shock absorber first end ( 391 ), shock absorber second end ( 393 ), shock absorber anchor ( 395 ), shock absorber pivot ( 392 ) and shock absorber front member ( 394 ); front frame transverse member ( 380 ). Also seen is rear main frame transverse member ( 240 ) at the rear ( 7 ), primary main frame members ( 210 ), rear stabilizing wheel frame ( 400 ) and stabilizing wheel ( 320 ) having a wheel axle and bearing means ( 500 ) with a stabilizing wheel ridge ( 330 ).  
         [0007]      FIG. 4  is a cutaway from  FIG. 3  showing features of  FIG. 3  absent the chair frame ( 100 ).  
         [0008]      FIG. 5  is a detail from  FIG. 4  illustrating the stabilizing wheel frame ( 300 ); front stabilizing frame ( 340 ), first end ( 342 ), second end ( 344 ), main frame member ( 210 ), main frame transverse member ( 220 ), front frame extension ( 360 ), transverse pivot ( 385 ). Also seen is shock absorber means ( 390 ), shock absorber first end ( 391 ), shock absorber second end ( 393 ), shock absorber anchor ( 395 ); shock absorber pivot ( 392 ), shock absorber front member ( 394 ) and front frame transverse member ( 380 ).  
         [0009]      FIGS. 6 and 6 A are sections from  FIG. 4  illustrating the stabilizing wheel ( 320 ) as ellipsoidal, spheroidal, or spherical having a major axis ( 440 ) and a minor axis ( 450 ) or a diameter ( 460 ), a stabilizing wheel ridge ( 330 ), stabilizing wheel axle support means ( 322 ), and stabilizing wheel support ( 325 ).  
         [0010]      FIG. 7  shows aligned apertures ( 600 ) in the second end ( 344 ) and in front frame extension ( 360 ) and locking pin ( 610 ). 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]      FIGS. 2, 3 ,  4  and  5  show the stabilizing wheel frame ( 300 ) having at least one front stabilizing frame ( 340 ); the at least one front stabilizing frame ( 340 ) having a first end ( 342 ) and a second end ( 344 ); a wheel means ( 320 ) shown as a stabilizing wheel ( 320 ) rotatably received by bearing and axle means ( 500 ) at the first end ( 342 ); the stabilizing wheel frame ( 300 ) is securely and fixedly received by removable means including locking pin ( 610 ) and aperture ( 600 ). Secure, fixedly and removable means fulfills the function of allowing conversion of the wheelchair ( 1 ) from a standard configuration of having front wheels ( 20 ) for travel over unobstructed smooth surfaces to the configuration of this invention and, likewise, to allow reconfiguration to the standard front wheels ( 20 ) when off-road travel resumes. Those of ordinary skills in mechanical arts will appreciate that in addition to locking pin ( 610 ) and aperture ( 600 ) that other mechanical means will be available including bolts, screws and quick release mechanisms.  
         [0012]      FIGS. 2, 3 ,  4  and  5  also show the main frame ( 200 ) frame means comprised of primary main frame members ( 210 ) which are generally of elongated tubular construction of rigid material which are in general alignment with the direction of movement of the wheel chair ( 1 ). Other frame construction will fulfill the equivalent structure and serve the equivalent purpose and function. The main frame ( 200 ) provides structure to which the invention of this patent discloses. Seen is at least one main frame transverse member ( 220 ) which is orthogonal to the direction of travel of the wheelchair ( 1 ). However, the orientation of the main frame transverse member ( 220 ) is indicated for convenience in facilitating the attachment of the wheel frame ( 300 ) so that the front stabilizing frame ( 340 ) members project outwardly from the front ( 3 ) of the wheelchair ( 1 ). The main frame transverse member may have other frame means configurations without bearing on the essence of the invention of this patent.  
         [0013]      FIGS. 3, 4  and  5  show the at least one front frame extension ( 360 ) which is immovably affixed by frame affixing means to a front frame transverse member ( 380 ). Frame affixing means includes welding, bolts, screws, and other permanent affixing means. However, a quick release fixing means may also be employed for the removal of portions of the stabilizing wheel frame ( 300 ) when off-road travel is not expected. The stabilizing wheel frame ( 300 ) is securely received at the second end ( 344 ) by the front frame extension ( 360 ) by front frame extension ( 360 ) affixing means.  
         [0014]      FIGS. 3, 4  and  5  illustrate the at least one transverse pivot ( 385 ) which is immovably affixed, by frame affixing means including welding and other mechanical methods, to the at least one main frame transverse member ( 220 ); the at least one transverse pivot ( 385 ) extends upwardly, via an elongated rigid tubular or solid metal material, presenting a tubular segment which is sized to receive rotatably and bracingly the at least one front frame transverse member ( 380 ). The at least one front frame transverse member ( 380 ) is rotatably received by the at least one transverse pivot ( 385 ). In the preferred embodiment there are at least two transverse pivots ( 385 ). The rotation of the at least one frame transverse member ( 380 ) is restrained by at least one shock absorber means ( 390 ). Shock absorber means is composed of at least one shock absorber ( 390 ) with spring, pneumatic and or hydraulic cylinder function. The shock absorber ( 390 ) has a shock absorber first end ( 391 ) and a shock absorber second end ( 393 ); the shock absorber ( 390 ) is immovably affixed by shock absorber affixing means at a shock absorber anchor ( 395 ); a shock absorber pivot ( 392 ) forms the shock absorber second end ( 393 ) which is pivotally affixed to a shock absorber front member ( 394 ); the shock absorber front member ( 394 ) is a linking means and is rigidly affixed to the front frame transverse member ( 380 ). Shock absorber ( 390 ) affixing means is by bolt or welding. The shock absorber anchor ( 395 ) is a tubular transverse member rigidly extending between the primary main frame members ( 210 ).  
         [0015]     As seen in  FIGS. 2, 3 ,  4 ,  5  and  6 , the at least one front frame extension ( 360 ) is tubular and is shaped and sized to receive the second end ( 344 ). Tubular affixing means secures the second end ( 344 ) at the at least one front frame extension ( 360 ).  
         [0016]      FIGS. 6 and 6 A show wheel means ( 320 ) which is identified as a stabilizing wheel ( 320 ). Wheel means ( 320 ) incorporates the elements of a wheel ( 320 ), axle and bearings ( 500 ), axle support means ( 322 ) and wheel support ( 325 ). Axle support means ( 322 ) is illustrated as a elongated tube which receives an axle. Wheel support ( 325 ) includes that content within a generally spheroidal body used for wheel purposes including pressurized gases and plastic or poly foams.  
         [0017]     Tubular affixing means, for the preferred embodiment, is composed of aligned apertures ( 600 ) in the second end ( 344 ) with aligned apertures ( 600 ) in the at least one front frame extension ( 360 ) where the aligned apertures ( 600 ) receive a locking pin ( 610 ).  
         [0018]     The at least one rear main frame transverse member ( 240 ) at the rear ( 7 ) is composed of an elongated tube rigidly affixed between the primary main frame members ( 210 ) and generally transverse to the direction of travel. An at least one rear stabilizing wheel frame ( 400 ) is rigidly affixed to the at least one rear main frame transverse member ( 240 ) and extends outwardly from the wheelchair rear ( 7 ). The at least one rear stabilizing wheel frame ( 400 ) rotatably, bracingly and axle receiving of at least one stabilizing wheel ( 320 ). In the preferred embodiment at least two rear stabilizing wheel frames ( 400 ) each receive a stabilizing wheel ( 320 ).  
         [0019]     The at least one front stabilizing frame ( 340 ), as seen in  FIGS. 2, 3  and  4  in the preferred embodiment, is composed of at least two front stabilizing frames ( 340 ) with at least one at the right ( 8 ) and one at the left ( 9 ). The stabilizing wheel ( 320 ) is ellipsoidal, spheroidal, or spherical having a major and minor axis or a diameter; the stabilizing wheel ( 320 ) receiving a wheel axle and bearing means ( 500 ) at the respective first ends ( 342 ) in alignment with the major or minor axis or along a diameter. The stabilizing wheel ( 320 ) in the preferred embodiment is spherical and is foam filled thereby giving sufficient structural strength to withstand the forces of the axle and bearings. Axle support means ( 322 ) composed of an elongated tube rotatably receiving an axle or of an aperture formed in the Stabilizing wheel ( 320 ) and contained stabilizing wheel support ( 325 ) of plastic or poly foam. The stabilizing wheel ( 320 ) has a stabilizing wheel ridge ( 330 ) protruding from the stabilizing wheel ( 320 ) at the circumference of the stabilizing wheel ( 320 ) equidistant between the respective first ends ( 342 ) and orthogonal to the surface of travel. The stabilizing wheel ridge ( 330 ) is concave. In the preferred embodiment the stabilizing wheel ridge ( 330 ) will be the portion of the stabilizing wheel ( 320 ) making contact with the surface which is being transited. The stabilizing wheel ridge ( 330 ) composed of a semi rigid plastic or poly material affixed by plastic or poly affixing means, including adhesive and stapling, to the stabilizing wheel ( 320 ). In instances where the surface has obstacles, such as pebbles or rocks, the portions of the stabilizing wheel ( 320 ) other than the stabilizing wheel ridge ( 330 ) will be in contact with surrounding obstacles and will resist stalling of forward motion and in getting stuck in soft earth or sand.  
         [0020]     The at least one stabilizing wheel ( 320 ) is ellipsoidal, spheroidal, or spherical having a major and minor axis or a diameter. In the preferred embodiment the stabilizing wheel ( 320 ) is spherical. At the rear ( 7 ) the at least one stabilizing wheel ( 320 ) receives a wheel axle and bearing means ( 500 ) at the respective at least one rear stabilizing wheel frame ( 400 ) in alignment with the major axis ( 440 ) or minor axis ( 450 ) or along a diameter ( 460 ). The at least one stabilizing wheel ( 420 ) at the rear ( 7 ) has a stabilizing wheel ridge ( 330 ) at the perimeter of the at least one stabilizing wheel ( 320 ) at the rear ( 7 ) along the major axis ( 440 ) or minor axis ( 450 ) or along a diameter ( 460 ) with the stabilizing wheel ridge ( 330 ) at the rear ( 7 ) being, in the preferred embodiment, orthogonal to the surface of travel and being concave.