Patent ID: 7364493

Claim:
An apparatus for grinding or polishing an optic, the apparatus comprising: a shell adapted to be bent into desired bending profiles, the shell having a top surface and a bottom surface configured for grinding or polishing the optic thereto; a plurality of torque actuators attached to the top surface of the shell at an outer edge thereto, the plurality of torque actuators further coupled to each other by cables, whereby the plurality of torque actuators apply bending moments to the edge of the shell; a tensioning system attached to the top surface of the shell at the outer edge thereto, the tensioning system applying further bending moments to the edge of the shell; and a control system for computing the desired bending profiles using the known structural parameters and controlling each of the torque actuators and the tensioning system according to the desired bending profiles for bending the shell to the desired bending profiles; wherein the tensioning system includes at least one force actuator attached to the edge of the shell; and a plurality of tensioning flexures linked to each other at a location distal from the edge of the shell, at least two tensioning flexures attached to the edge of the shell at spaced locations spaced apart from each other and at least one tensioning flexture attached to the at least one force actuator.