US Patent 10105568 Stair climber apparatuses and methods of operating stair climber apparatuses

Stair climber apparatuses have a control circuit that controls the speed and torque of an electric motor and controls an output torque direction of the electric motor. The control circuit controls the speed of the electric motor and the output direction of the electric motor to maintain a constant speed of travel of a plurality of stairs in a downward direction along an inclined support when an operator is stepping on the plurality of stairs in an upward direction. When a change in output torque direction of the electric motor torque is required to maintain the constant speed of travel of the plurality of stairs in the downward direction along the inclined support, the control circuit controls the speed of the electric motor down to a zero speed. Methods are for operating the stair climber apparatuses.