1. Technical Field
This invention relates to upright wheelchairs that are used to move handicapped or injured persons. The wheelchairs are chair configurations with two large drive wheels and usually a pair of secondary multi-directional support wheels.
2. Description of Prior Art
Prior Art devices of this type have relied on a variety of different designs for hand driven actuation of the main drive wheels through a variety of structures.
In U.S. Pat. No. 4,274,650 a wheelchair is disclosed having a hand drive assembly consisting of a multiple gear configuration connecting the main drive axle via an intermediate gear to a hand drive gear. The drive assembly is used on a standard wheelchair configuration so that the user can propel the chair forward by rotation of cranks associated with the drive mechanism.
In U.S. Pat. No. 4,506,901 shows a hand-propelled chariot having a seat configuration with a chain drive with inner-connected gears on the drive axle and a hand crank. The user sits in the chair and cranks the handle driving the chair and inner-connected drive axle moving the chair forward. Each drive axle wheel is independently actuated for maximum maneuverability.
U.S. Pat. No. 3,249,368 discloses a device that supports the uses in an upright i.e. standing position on a multiple wheeled frame. The user has a pair of poles that he or she uses to push himself and the attached wheeled frame forward.