Abstract: A device for dampening the vibration of a rotating disc during the machining of the faces thereof has a spring member having a wide base portion and two arms extending from the ends of the base. At the face end of each arm is a pad mounted to pivot about an axis perpendicular to the axis of the arm. A dampening device in accordance with this invention has eye shields without requiring that the eye shield be removed.

Abstract: An external drive assembly is provided which conveys rotational movement to a shaft, and the shaft is adapted to be positioned substantially coaxial with the axis of the wheel hub of a motor vehicle. An adjustable drive member extends from the distal end of the shaft to the center of an adapter hub attachable to the wheel hub. Adjustable lug adapter legs are provided in which one end of each of such legs is adapted to attach to the threaded studs of an automobile wheel hub and the other end of each of the legs is provided with a cylindrical pin adapted to fit within one of a plurality of bores spaced around the peripheral edge of the adapter hub to retain the adapter leg within the adapter hub.

Abstract: An electrically operated drive assembly for turning a motor vehicle disc brake rotor while the rotor is still on the vehicle includes a portable stand or base having a combination electric motor and adjustable drive shaft assembly pivotally mounted thereon. The end of the drive shaft is selectably releaseably retained on a lug adapter mechanism that is retained on the motor vehicle wheel lugs. The drive shaft assembly includes a right angle bend that allows the entire drive assembly to be positioned to one side of the motor vehicle wheel hub and rotor assembly. This arrangement allows a mechanic to have open access to a separate portable brake lathe which is mountable on the vehicle brake caliper mounting bosses. The drive assembly turns the brake rotors at a predetermined speed which is suitable for combined operation with a portable brake lathe.

Abstract: A method of measuring the runout between a gauge and the axis of rotation of a wheel to which the gauge is mounted in each of two orthogonally related planes uses measurements of the angle between the axis of rotation of the wheel and the axis on which two or more angle sensors are pendulously supported at two or more rotational positions of the wheel and measurements of the angle of rotation of the wheel at each of said rotational positions to derive a runout equation which may be subsequently used to compute the runout at every possible rotational position of the wheel.