Patent ID: 8823220

Claim:
A positioning system for positioning a positioning unit along a longitudinal axis, the positioning system comprising: a linear guide arrangement for enabling a linearly guided motion parallel to said axis, the positioning unit being operatively connected to said guide arrangement, a motor comprising a moving motor member operatively connected to said linear guide arrangement and an elongated stationary motor member extending parallel to said axis, the moving motor member being adapted to move along the stationary motor member for providing motion parallel to said axis; and a force transmission arrangement operatively connecting said moving motor member to the positioning unit, wherein the force transmission arrangement is arranged to provide a semi-rigid engagement between said positioning unit and said moving motor member, said semi-rigid engagement being rigid in a direction parallel to said axis for instantaneous transmission of a linear force, and being resilient in directions other than said direction parallel to said axis, whereby transmission to the positioning unit of forces arising from thermal expansion of the motor is reduced or eliminated, wherein the positioning unit and the moving motor member, respectively, are operatively connected to the linear guide arrangement by at least two guide engaging carriages, and wherein the positioning unit is attached to the guide engaging carriages by rigid or resilient positioning unit holders.