Abstract: A scrub head includes a first disc scrub member, a movable support having first and second positions, and a movable disc scrub member. The first disc scrub member is rotatable about a first vertical axis. The movable disc scrub member is rotatable about a second vertical axis and is connected to the movable support. The movable disc scrub member is configured to move relative to the first disc scrub member along first and second orthogonal axes of a horizontal plane, which is transverse to the first and second vertical axes, between first and second positions respectively corresponding to the first and second positions of the movable support.

Abstract: A rider surface maintenance vehicle with variable dynamic braking, in contrast to a mechanically-engaged braking system that uses a brake cable. A brake pedal engages a sensor that encodes the pedal position as an electronic signal. The electronic signal, along with the vehicle velocity, determines a machine deceleration rate, or braking rate, either by calculation, lookup table, or a combination of the two. The braking rate may be tuned so that the of the brake mimics or approximates the feel of a conventional mechanically-engaged brake that uses a brake cable. During stopping, once the vehicle passes below a threshold velocity, a parking brake is automatically engaged. The braking rate is converted to a duty cycle, and the braking is preferably accomplished by pulse width modulation (PWM) of an electrical load applied in parallel to the motor.

Abstract: A scrub head includes a first disc scrub member, a movable support having first and second positions, and a movable disc scrub member. The first disc scrub member is rotatable about a first vertical axis. The movable disc scrub member is rotatable about a second vertical axis and is connected to the movable support. The movable disc scrub member is configured to move relative to the first disc scrub member along first and second orthogonal axes of a horizontal plane, which is transverse to the first and second vertical axes, between first and second positions respectively corresponding to the first and second positions of the movable support.