Abstract: A vehicle is disclosed having a pair of drive wheels, at least one ground-engaging front wheel connected to the frame forward of the drive wheels and at least one ground-contacting anti-tip wheel mounted to the vehicle rearward of the drive wheels. The drive wheels and anti-tip wheels are mounted on common suspension arms, pivoted to the frame of the vehicle behind the drive wheels and resiliently suspended, so that the anti-tip wheels move up and down in response to movements of the drive wheel suspension.

Abstract: A powered vehicle has a rear frame assembly and a front frame assembly that are pivotally attached to one another, and can be pivoted from a normal fully-extended operating position to a folded position in which the frame assemblies are positioned substantially adjacent to one another, effectively reducing overall vehicle length to about half. One or more latch members lock the front and rear frame assemblies in the fully-extended, normal operating position, and they may be used to lock the frame assemblies in the folded position. The seat support structure may be integrated with the front and rear frame assemblies such that pivoting the frame assemblies toward the folded position collapses the seat support. The steering tiller may also be collapsible toward the front frame assembly. The rear wheels may be mounted on a transaxle that is pivotally mounted on the rear frame assembly. An extendable handle may be provided to assist in the folding operation and to tow the collapsed vehicle on its anti-tip rollers.

Abstract: An active anti-tip system is provided for a wheelchair having a main structural frame and a drive assembly. The anti-tip system includes at least one anti-tip wheel, a suspension arm assembly pivotally mounting the anti-tip wheel to the main structural frame, a pendulum mount for coupling the drive assembly to the main structural frame and intermeshing gears for conveying the motion of the drive assembly to the suspension arm assembly. The pendulum mount causes the drive assembly to traverse in a substantially horizontal path in response to torque input from the drive assembly. The motion of the drive train assembly is converted to pivot motion of the suspension arm by the intermeshing gears. The pivot motion of the suspension arm assembly causes the anti-tip wheel to be raised for curb/obstacle climbing and effectively lowered for pitch stability.

Abstract: A powered vehicle has a rear frame assembly and a front frame assembly that are pivotally attached to one another, and can be pivoted from a normal fully-extended operating position to a folded position in which the frame assemblies are positioned substantially adjacent to one another, effectively reducing overall vehicle length to about half. One or more latch members lock the front and rear frame assemblies in the fully-extended, normal operating position, and they may be used to lock the frame assemblies in the folded position. The seat support structure may be integrated with the front and rear frame assemblies such that pivoting the frame assemblies toward the folded position collapses the seat support. The steering tiller may also be collapsible toward the front frame assembly. The rear wheels may be mounted on a transaxle that is pivotally mounted on the rear frame assembly. An extendable handle may be provided to assist in the folding operation and to tow the collapsed vehicle on its anti-tip rollers.

Abstract: A curb-climbing rear wheel drive power wheelchair is disclosed having a pair of drive wheels, at least one ground-engaging idler wheel connected to the frame forward of the drive wheels and at least one anti-tip wheel mounted above ground aft of the drive wheels. Each drive wheel and an associated drive assembly are mounted to a motor support bracket that is pivoted to the frame of the wheelchair. The drive assembly is mounted such that its motor is angled upward and rearward from the bracket. The anti-tip wheel is attached to one motor support bracket such that pivoting of the motor support bracket causes vertical displacement of the anti-tip wheel.