Device for adjusting the tension of a pulling element

Apparatus for adjusting an effective length of a pulling element comprising:

• a first mounting frame, said first mounting frame having an aperture adapted to receive an end portion of a first section of said pulling element;
• a second mounting frame, said second mounting frame having an aperture adapted to receive an end portion of a second section of said pulling element, said first mounting frame being arranged for sliding motion with a housing supporting said second mounting frame, said first mounting frame being constrained against rotation relative to said housing by at least one lateral projection engaging a sliding surface between said first mounting frame and said housing;
• a spindle comprising a rigid body having a first end and a second end, the first end comprising an elongate threaded portion having a longitudinal axis defining an axial direction, the second end comprising a substantially disk-shaped portion, the elongate threaded portion including overhauling threads engaging corresponding overhauling threads on said first mounting frame, the substantially disk-shaped portion having a first surface comprising an end adapted to engage a bearing surface on said second mounting frame, the substantially disk-shaped portion having a second surface opposite the first surface, the second surface adapted to engage a friction surface on said second mounting frame, the disk-shaped portion being mounted to the second mounting frame for rotation with sufficient axial backlash to enable the threaded spindle to move between a first position in which the end of the substantially disk-shaped portion engages the bearing surface and the second surface is spaced-apart from the friction surface to allow rotation of the spindle, to a second position in which the end disengages the bearing surface and the second surface engages the friction surface to prevent rotation of the spindle;
• and
• an elastic member exerting a force in the axial direction, which moves said first mounting frame toward said second mounting frame and simultaneously causes the spindle to rotate to reduce the effective length of the pulling element as said pulling element moves from a tensioned to an un-tensioned state.