Mechanical apparatus

摘要

The precision drive arrangement comprises a spherical ball 260 within which there is housed an electric motor 271 having an axial hollow drive shaft 261 through which a elongate rectilinear member is adapted to extend with a driving interaction between the motor and the elongate member. An annular mounting collar for the spherical ball has an internal part-spherical surface complementary to the spherical surface of the ball and contiguous with the ball surface. Relative rotational movement between the ball and the collar is permitted except in a direction about the axis of the motor drive shaft.