Patent ID: 8220806
Filing Date: 2012-07-17
Classification: B24B

Abstract:
1. A surface milling system comprising: a datum device for generating a reference plane; a support frame; a grinder supported by the support frame; at least first, second and third wheels on which the support frame is supported; at least first, second and third actuators for raising and lowering the first, second and third wheels relative to the support frame, the first actuator being adapted to raise and lower the first wheel, the second actuator being adapted to raise and lower the second wheel and the third actuator being adapted to raise and lower the third wheel; a first receiver corresponding to the first actuator for detecting the reference plane; a second receiver corresponding to the second actuator for detecting the reference plane; a third receiver corresponding to the third actuator for detecting the reference plane; and wherein data from the first, second and third receivers is used to control the first, second and third actuators such that the support frame is maintained at a constant position relative to the reference plane even when the support frame moves across a surface of varying elevation, wherein the datum device is not carried by the support frame such that the support frame is movable with respect to the datum device.