Electric drive for wheel chairs
OwnerHarold Cragginventor
Life of this patent
Estimating the term…
Abstract
In a wheelchair, battery operated electric driving means for driving two wheels each mounted on a wheel plate connected to the wheelchair frame. For each driven wheel a motor is carried on the wheel plate and drive is transmitted to a pinion fixed on the wheel through a pivotal gear carrier carrying one or two idler gears in constant mesh with the fixed pinion, but movable into or out of mesh with a motor driven pinion on controlled pivotal movement of the gear carrier.
Claims16
Electric driving means for a wheelchair comprising a wheel plate, an electric motor mounted on said wheel plate and operable by a battery through control means, drive transmitting means on said wheel plate coupled to the electric motor and including an output shaft carrying a driven pinion, a rotatable wheel supported on said wheel plate and carrying a fixed pinion, mounting means for mounting said wheel plate on a frame member of the wheelchair, and a gear carrier mounted for pivotal movement relative to said fixed and driven pinions between a first extreme position, a neutral position, and a second extreme position, the gear carrier including first idler gear means for transmitting drive from the driven pinion to the fixed pinion when the gear carrier is in said first extreme position and second idler gear means having a drive transmission ratio different to that of said first idler gear means for transmitting drive from the driven pinion to the fixed pinion when the gear carrier is in said second extreme position.
In a wheelchair having a frame supporting a pair of castor wheels, a paid of drive wheel assemblies, and a battery, the improvement wherein each of said drive wheel assemblies comprises
- a support,
- an electric motor on said support and operable by said battery through a control means,
- drive transmitting means coupled to the electric motor and having an output shaft carrying a drive pinion,
- a drive wheel rotatably mounted on said support and carrying a fixed pinion, and
- gear transmission means on said support for coupling said drive pinion to said fixed pinion, said gear transmission means including a gear carrier mounted for pivotal movement relative to said fixed and drive pinions between a first extreme position and a neutral position, the gear carrier including at least one idler gear means for transmitting drive torque from the drive pinion to the fixed pinion when the gear carrier is in said first extreme position, and said carrier being moved by a rotatable eccentric engaging a cam bush on said gear carrier.
Dependencies are inferred from the claim text.