Patent ID: 8714434

Claim:
A weight balancer; comprising: an operation plate for putting an alignment object; a plurality of load cells installed in the lower portion of the operation plate; a controller which receives a detection signal generated from the load cell and analyses the information of the alignment object to generate a control signal; an operation force driver which receives the control signal from the controller to control an operational pressure of each of a plurality of pressure supply lines; and a plurality of leveling cylinders and balancing devices which are connected to the pressure supply lines to control a location or pose of the operation plate so as to correspond to a size of the operational pressure controlled by the operation force driver, wherein the operation plate includes an upper plate and a lower plate between which a plurality of slide contact parts are arranged, and an upper surface of an edge beam is stuck to the bottom surface of the edge of the upper plate, wherein the upper plate is transitionally slidable with respect to the lower plate, and wherein a plurality of gap maintaining shafts attached in the edge beam are projected toward a side surface of the lower plate so that a distance between the side surface of the lower plate and the edge beam is maintained to be variable but to be greater than projected lengths of the gap maintaining shafts.