Patent ID: 7839584

Claim:
An X-Y displacement unit for positioning a surgical microscope along orthogonal X and Y directions, the X-Y displacement unit comprising: a frame; a first stepper motor and a second stepper motor each mounted on the frame; a first threaded spindle extending in the X direction through a housing of the first stepper motor, the first threaded spindle being driven by the first stepper motor in the X direction; a second threaded spindle extending in the Y direction through a housing of the second stepper motor, the second threaded spindle being driven by the second stepper motor in the Y direction; a first carriage connected to the first threaded spindle for travel with the first threaded spindle in the X direction; a second carriage connected to the second threaded spindle for travel with the second threaded spindle in the Y direction; a first elastomeric damper arranged to receive the first threaded spindle, the first threaded spindle being connected to the first carriage via the first elastomeric damper such that no direct connection exists between the first threaded spindle and the first carriage; and a second elastomeric damper arranged to receive the second threaded spindle, the second threaded spindle being connected to the second carriage via the second elastomeric damper such that no direct connection exists between the second threaded spindle and the second carriage.