Backlash compensating assembly

A nut assembly comprising:

• a first nut portion having a threaded bore;
• a second nut portion having a threaded bore and coupled to the first nut portion to prevent relative rotation but permit movement in an axial direction;
• a substantially rigid sleeve rotatable with respect to the first and second nut portions, the sleeve having one end engaging the first nut portion and an opposite end engaging the second nut portion, one of the ends of the sleeve provided with at least one ramped surface engaging at least one complimentary ramped surface provided on one of the first and second nut portions;
• and
• means for biasing the sleeve to rotate with respect to the first and second nut portions such that said ramped surfaces slide relative to each other to move said one nut portion in an axial direction with respect to the other nut portion.

An apparatus comprising:

• a threaded drive shaft;
• a nut assembly threadedly engaged with the drive shaft so as to move axially upon rotation of the drive shaft, the nut assembly comprising:
• a first nut portion with a bore threadedly engaged with the drive shaft;
• a second nut portion with a bore threadedly engaged with the drive shaft, the bore of the first nut portion being axially aligned with the bore of the second nut portion, the first and second nut portions coupled to prevent relative rotation but permit relative movement in an axial direction;
• a rotatable member disposed between the first and second nut portions, the rotatable member having at least one cam surface engaging the first nut portion wherein relative rotation of the member and the nut portions cams the first nut portion away from the second nut portion to take up backlash between the threads of the nut portions and the drive shaft;
• and
• means for biasing the member to rotate with respect to the first and second nut portions.