Alternately-Propelled Mechanical Wheelchair (APMW) is a modified wheelchair that incorporates a superior braking system and eliminates complete hand-to-rail contact when moving forward. By incorporating a clutch system engaged by air cylinders, the user can apply a relatively small amount of force to travel further than a traditional wheelchair. The APMW is designed for a range of users, including children of eight years and older, people of diminished upper body capacity, and individuals seeking an easier mode of transportation.
The APMW consists of a drive system similar to that seen on a mountain bike. It incorporates a main drive gear that is connected to a bicycle chassis by means of a chain. The chassis is attached to the drive shaft, which consists of a male gear on each side. Two handles are mounted on a guide rail on each side of the user. The right handlebar consists of a brake lever and a twist-shifter. When the handles are moved in a forward motion, a main air cylinder pumps oil along a tube and allows two secondary cylinders to engage the female gear into the male gear. As a result of this engagement, the rotating shaft rotates the wheels. Each wheelchair wheel consists of a clutch bearing, which is a one-way bearing that allows for freewheel motion when the clutch is not engaged. As a result, the user no longer has to use his hands to propel and stop the wheelchair. The total cost for parts and supplies for the prototype is approximately $ 827.