Abstract: A power wheelchair is provided having one or more anti-tip wheels for stabilizing the movement of the frame about the drive wheels. An anti-tip wheel is attached to the end of a suspension arm which is pivotally attached to the frame of the wheelchair. A spring resiliently supports the anti-tip wheel in a neutral position relative to the ground upon which the drive wheels of the wheelchair normal ride. A retaining system selectively fixes position of the anti-tip wheels relative to the frame. The retaining system employs a plurality of teeth, with one portion disposed in combination with said suspension arm, and at least one other tooth disposed for engaging said one portion to provide unidirectional retention of the position of said suspension arm relative to the frame. The engagement of the teeth to lock the position of the suspension arm may be responsive to the torque generated by the motor.

Abstract: A personal mobility vehicle is steered by handlebars. A lever is mounted on the handlebars and rotatable in either of two opposite directions by the hands holding the handlebars. A potentiometer connected to the lever comprises a wiper on a resistive track, centered by a spring. The track has a central null area formed by material of lower resistance, so that the output voltage is constant. When the lever is moved away from the centered position, the wiper moves along the track and the output voltage rises or falls. A controller controls the speed and direction of the vehicle in response to the output voltage of the potentiometer. When the wiper is on the null area, the controller stops the vehicle. The size of the null area facilitates ensuring the centered position coincides with the null area, so the vehicle stops when the lever is released.

Abstract: An electric scooter is disclosed that has a propulsion system switchable between two modes, one of which allows a higher maximum speed than the other. The mode is selected by a user operated button so constructed that the high-speed mode is selected only while the user continues to operate the switch. A steering angle sensor and a tilt switch-are provided, which prevent the user from selecting the high-speed mode while steering sharply or while going down or across steep slopes.

Abstract: An electric scooter is disclosed that has a propulsion system switchable between two modes, one of which allows a higher maximum speed than the other. The mode is selected by a user operated button so constructed that the high-speed mode is selected only while the user continues to operate the switch. A steering angle sensor and a tilt switch are provided, which prevent the user from selecting the high-speed mode while steering sharply or while going down or across steep slopes.