U.S. Patent 5,326,121 Fisher July 5, 1994

A safe, efficient, human powered vehicle for on and off road use. The preferred embodiment has four wheels and seats two operators side by side. The vehicle incorporates several features which drastically reduce the energy required to propel such a vehicle and optimizes the energy produced from the operators. Each operator is provided with an independent foot pedal and drive mechanism. Each independent drive mechanism has multiple speeds which are independently controlled by each operator. The invention allows each operator to provide power to both rear wheels simultaneously. The drive train includes a simple, lightweight, energy efficient freewheel mechanism which acts as a differential and allows each rear wheel to rotate at different speeds when turning corners. This differential mechanism saves energy by eliminating tire skid which occurs when both rear wheels rotate at the same speed during a turn. The suspension system is energy efficient. Both the front and rear suspension systems keep each wheel parallel to the other wheels throughout the suspension travel. The suspension design reduces energy loss due to toe change, bump steer, and the like. The vehicle incorporates a unique braking control mechanism which increases maneuverability and control of the vehicle. The vehicle’s four wheel design provides increased stability and safety over