Slider for adjusting the position of the dual axles of a semi-trailer

In a system for adjusting the position of the dual rear axle assembly of a semi-trailer of the type having a track extending longitudinally along the bottom thereof which is provided with a longitudinal array of apertures;

• a slidable carriage, supporting a dual rear axle assembly having wheels at each end of its axles;
• said carriage being mounted on said track for sliding motion along said track to a desired position;
• and pin means affixed to said carriage, said pin means being extendable into said apertures to fix the position of said carriage with respect to said track and being retractable to permit sliding of said carriage along said track;
• the improvement comprising the combination therewith of:
• braking means for holding said semi-trailer fixed while leaving said wheels free to roll along the ground;
• controllable carriage-positioning means having a proximal and a distal and being affixed to said semi-trailer and acting between said track and said carriage for selectively adjusting the longitudinal position of said carriage along said track as said wheels thereof roll along the ground said controllable carriage-positioning means comprising a control cable having position-control switch means at the distal end thereof, which switching means are operative from beside said semi-trailer to control the position of said carriage;
• and
• pin-control means affixed to said carriage for retracting said pin means to free said carriage for sliding motion during said adjusting of said carriage position, and for selectively extending said pin means into said apertures when said carriage is in said desired position said pin-control means comprises said control cable having pin-control switch means at the distal end thereof and operable from a position beside said semi-trailer to control said pin means.