摘要 |
An apparatus for measuring and controlling the force exerted on a disc by a rotating pad. More specifically, the present invention relates to an apparatus for controlling the forces exerted by a plurality of polishing pads used for polishing the surfaces of rigid computer memory discs. The spring mechanism that provides the load force to a free sliding shaft which transmits the force to the polishing member is fitted with a suitable transducer, such as a strain gauge, which senses the axial force transmitted down the sliding shaft to the polishing pads by way of the force/strain relationship of the spring mechanism. The strain sensed by the transducer is converted to an electrial signal which is conducted to the input of a closed loop, feedback control servo system which maintains the desired contact force of the pads on the disc and, at the same time, maintains an equality of forces on each side of the disc.
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