초록 ▼

A manually-powered wheelchair that includes one or more features that enhance the overall maneuverability and stability of the wheelchair, such as centrally mounted drive-wheels and an anti-tip system. Other embodiments may include at least one of an adjustable anti-tip system that may be selectivel

A manually-powered wheelchair that includes one or more features that enhance the overall maneuverability and stability of the wheelchair, such as centrally mounted drive-wheels and an anti-tip system. Other embodiments may include at least one of an adjustable anti-tip system that may be selectively located to several locations on the frame; a positive stop device attached to either the mounting bracket, frame, or the anti-tip system for limiting movement of the anti-tip system and the frame relative to each other; a resistance device attached to the frame and the anti-tip system for increasing resistance between the frame and the anti-tip system when the user leans backwards in the wheelchair; a wheel lock system engaging at least one of the drive wheels below the wheel's axis of rotation; and a tilt prevention device for selectively preventing any rotation of the wheelchair frame and anti-tip system relative to each other.

대표청구항 ▼

What is claimed: 1. A manually powered anti-tip wheelchair, comprising: a frame, the frame providing structural support for a seat; a pair of drive wheels, each of the pair of drive wheels having an axis of rotation; at least one front wheel mounted to a portion of the frame; at least one anti-tip

What is claimed: 1. A manually powered anti-tip wheelchair, comprising: a frame, the frame providing structural support for a seat; a pair of drive wheels, each of the pair of drive wheels having an axis of rotation; at least one front wheel mounted to a portion of the frame; at least one anti-tip assembly, comprising: (i) a pivot arm, the pivot arm including a wheel; (ii) a drive wheel attachment point for attachment of at least one drive wheel to the anti-tip assembly; and (iii) a frame attachment point, separate from and located rearward of the drive wheel attachment point, adapted to rotatably mount the anti-tip assembly to the frame, the at least one drive wheel and the pivot arm thereby being mounted to the frame, wherein the at least one drive wheel and pivot arm wheel are both adapted to contact a ground surface when the wheelchair is in use, wherein the at least one drive wheel and pivot arm wheel each support a portion of the weight of the frame of the wheelchair when in contact with the ground surface, and wherein the frame may rotate relative to the anti-tip assembly while the at least one drive wheel and pivot arm wheel remain in contact with the ground surface; and a stop device mounted on one of the pivot arm or the frame, the stop device selectively contacting the other of the pivot arm or the frame to limit the movement of the frame and pivot arm relative to each other, the stop device positioned to permit the frame to tilt back into a predetermined stable tilted position with the at least one front wheel in a raised position in such a manner that a user may sit in the seat of the wheelchair with the at least one front wheel engaging the ground surface, tilt the frame back into the predetermined stable tilted position, and operate the wheelchair with the at least one front wheel in the raised position. 2. The manually powered anti-tip wheelchair of claim 1, wherein said stop device is mounted to the frame and engages the anti-tip subassembly to limit the movement of the frame and anti-tip subassembly relative to each other. 3. The manually powered anti-tip wheelchair of claim 2, wherein the frame further comprises a plurality of separate stop device attachment points for attaching said stop device. 4. The manually powered anti-tip wheelchair of claim 1, wherein said stop device is mounted to the anti-tip assembly and engages the frame to limit the movement of the frame and anti-tip assembly relative to each other. 5. The manually powered anti-tip wheelchair of claim 4, wherein the anti-tip assembly further comprises a plurality of separate stop device attachment points for attaching said stop device. 6. The manually powered anti-tip wheelchair of claim 1, wherein said drive wheel attachment point of the anti-tip assembly is located on the pivot arm. 7. The manually powered anti-tip wheelchair of claim 1, wherein said drive wheel attachment point of the anti-tip assembly is connected with the pivot arm. 8. The manually powered anti-tip wheelchair of claim 1, wherein said at least one front wheel is a caster wheel. 9. The manually powered anti-tip wheelchair of claim 1 further comprising a resistance device, the resistance device engaging with the frame and the anti-tip assembly to resist the movement of the frame and anti-tip assembly relative to each other. 10. The manually powered anti-tip wheelchair of claim 9, wherein said resistance device is mounted to the frame and engages the anti-tip assembly to resist the movement of the frame and anti-tip assembly relative to each other. 11. The manually powered anti-tip wheelchair of claim 9, wherein said resistance device is mounted to the anti-tip assembly and engages the frame to resist the movement of the frame and anti-tip assembly relative to each other. 12. The manually powered anti-tip wheelchair of claim 9 wherein said resistance device includes at least one spring. 13. The manually powered anti-tip wheelchair of claim 9 wherein said resistance device comprises a gas pressurized spring. 14. The manually powered anti-tip wheelchair of claim 1 further comprising a wheel lock including a wheel engaging element selectively moveable to engage at least one of the pair of drive wheels below the axis of rotation of said at least one of the pair of drive wheel. 15. The manually powered anti-tip wheelchair of claim 1 wherein the frame includes multiple, discrete anti-tip assembly attachment points to allow for attachment of the anti-tip assembly at different locations on the frame. 16. The manually powered anti-tip wheelchair of claim 1 wherein the anti-tip assembly includes multiple, discrete frame attachment points to allow for attachment of the frame at different locations on the anti-tip subassembly. 17. The manually powered anti-tip wheelchair of claim 1 wherein the anti-tip assembly includes multiple, discrete drive wheel attachment point for attachment of at least one drive wheel at different locations on the anti-tip subassembly. 18. The manually powered anti-tip wheelchair of claim 1 further comprising a wheel lock including a wheel engaging element selectively moveable to engage at least one of the pair of drive wheels below the axis of rotation of said at least one of the pair of drive wheel; and wherein the frame includes multiple, discrete anti-tip assembly attachment points to allow for attachment of the anti-tip assembly at different locations on the frame. 19. A manually powered anti-tip wheelchair, comprising: a frame, the frame providing structural support for a seat; a pair of drive wheels, each of the pair of drive wheels having an axis of rotation; at least one front wheel mounted to a portion of the frame; at least one anti-tip assembly, comprising: (i) a pivot arm, the pivot arm including a wheel; (ii) a drive wheel attachment point for attachment of at least one drive wheel to the anti-tip assembly, wherein the at least one drive wheel attaches directly to the pivot arm via the drive wheel attachment point; and (iii) a frame attachment point, separate from and located rearward of the drive wheel attachment point, adapted to rotatably mount the anti-tip assembly to the frame, the at least one drive wheel and the pivot arm thereby being mounted to the frame, wherein the at least one drive wheel and pivot arm wheel are both adapted to contact a ground surface when the wheelchair is in use, wherein the at least one drive wheel and pivot arm wheel each support a portion of the weight of the frame of the wheelchair when in contact with the ground surface, and wherein the frame may rotate relative to the anti-tip assembly while the at least one drive wheel and pivot arm wheel remain in contact with the ground surface; and at least one wheel lock including a wheel engaging element selectively moveable to engage at least one of the pair of drive wheels below the axis of rotation of the at least one of the pair of drive wheels. 20. The manually powered anti-tip wheelchair of claim 19, wherein the frame includes multiple, discrete anti-tip assembly attachment points to allow for attachment of the anti-tip assembly at different locations on the frame. 21. A manually powered anti-tip wheelchair, comprising: a frame, the frame providing structural support for a seat; a pair of dhive wheels, each of the pair of drive wheels having an axis of rotation; at least one front wheel mounted to a portion of the frame; at least one anti-tip assembly, comprising: (i) a pivot arm, the pivot arm including a wheel; (ii) a drive wheel attachment point for attachment of at least one drive wheel to the anti-tip assembly, wherein the at least one drive wheel attaches directly to the pivot arm via the drive wheel attachment point; and (iii) a frame attachment point, separate from and located rearward of the drive wheel attachment point, adapted to rotatably mount the anti-tip assembly to the frame, the frame having multiple discrete anti-tip assembly attachment points to allow for attachment of the anti-tip assembly at different locations on the frame, the at least one drive wheel and the pivot arm thereby being mounted to the frame, wherein a portion of the at least one drive wheel and pivot arm wheel are both adapted to contact a ground surface when the wheelchair is in use, wherein the at least one drive wheel and pivot arm wheel each support a portion of the weight of the frame of the wheelchair when in contact with the ground surface, and wherein the frame may rotate relative to the anti-tip assembly while the at least one drive wheel and pivot arm remain in contact with the ground surface; and a stop device mounted on one of the pivot arm or the frame, the stop device selectively engaging the other of the pivot arm or the frame to limit the movement of the frame and pivot arm relative to each other. 22. A manually powered anti-tip wheelchair, comprising: a frame, the frame providing structural support for a seat; left and right drive wheels, each of the drive wheels having an axis of rotation; at least one front caster mounted to a portion of the frame; a pair of anti-tip assemblies, comprising: (i) a pivot arm having front and rear ends; (ii) a rear caster wheel mounted to the pivot arm proximate the rear end of the pivot arm and the pivot arm further having an associated one of the drive wheels mounted to the pivot arm at a drive wheel attachment point proximate the front end of the pivot arm; and (iii) a frame attachment point, located on the pivot arm between the rear caster wheel and the drive wheel attachment point, adapted to rotatably mount the pivot arm and the associated one of the drive wheels to the frame; (a) wherein the associated one of the drive wheels and the rear caster wheel are both adapted to contact a ground surface when the wheelchair is in use; and (b) wherein the frame may rotate relative to the pivot arm while the associated one of the drive wheels and the rear caster wheel remain in contact with the ground surface; and a stop device mounted on one of the pivot arm or the frame, the stop device selectively engaging the other of the pivot arm or the frame to limit the movement of the frame and the pivot arm relative to each other, the stop device positioned to permit the frame to tilt back into a predetermined stable tilted position with the at least one front caster in a raised position in such a manner that a user may sit in the seat of the wheelchair with the at least one caster engaging the ground surface, tilt the frame back into the predetermined stable tilted position, and operate the wheelchair with the at least one front caster in the raised position. 23. The manually powered anti-tip wheelchair of claim 22, wherein the at least one caster is raised high enough off of the ground surface while the frame is in the predetermined stable tilted position that the at least one front caster clears an obstacle that is about six inches high as the manually powered anti-tip wheelchair is operated on the ground surface toward the obstacle so that the drive wheels contact the obstacle. 24. The manually powered anti-tip wheelchair of claim 22, wherein the at least one caster is raised high enough off of the ground surface while the frame is in the predetermined stable tilted position that the at least one front caster clears an obstacle as the manually powered anti-tip wheelchair is operated on the ground surface toward the obstacle so that the drive wheels contact the obstacle. 25. The manually powered anti-tip wheelchair of claim 23 further comprising a wheel lock including a wheel engaging element selectively moveable to engage at least one of the drive wheels below the axis of rotation of the at least one drive wheel. 26. A manually powered anti-tip wheelchair, comprising: a frame, the frame providing structural support for a seat; a pair of drive wheels, each of the pair of drive wheels having an axis of rotation; at least one front wheel mounted to a portion of the frame; at least one anti-tip assembly, comprising: (i) a pivot arm, the pivot arm including a wheel; (ii) a drive wheel attachment point for attachment of at least one drive wheel to the anti-tip assembly, wherein the drive wheel attachment point comprises a location directly on the pivot arm or directly on a pivot arm bracket connected to a projecting end of the pivot arm; and (iii) a frame attachment point, separate from and located rearward of the drive wheel attachment point, adapted to rotatably mount the anti-tip assembly to the frame, the at least one drive wheel and the pivot arm thereby being mounted to the frame, wherein the at least one drive wheel and pivot arm wheel are both adapted to contact a ground surface when the wheelchair is in use, wherein the at least one drive wheel and pivot arm wheel each support a portion of the weight of the frame of the wheelchair when in contact with the ground surface, and wherein the frame may rotate relative to the anti-tip assembly while the at least one drive wheel and pivot arm wheel remain in contact with the ground surface; and a stop device mounted on one of the pivot arm or the frame, the stop device selectively contacting the other of the pivot arm or the frame to limit the movement of the frame and pivot arm relative to each other, the stop device positioned to permit the frame to tilt back into a predetermined stable tilted position with the at least one front wheel in a raised position in such a manner that a user may sit in the seat of the wheelchair with the at least one front wheel engaging the ground surface, tilt the frame back into the predetermined stable tilted position, and operate the wheelchair with the at least one front wheel in the raised position.