Sliding door closed loop cable closure system with balanced cable tension and varying diameter pulleys

A sliding door opening and closing system for a vehicle including a vehicle frame;

• at least one track mounted on the vehicle frame;
• a sliding door supported by the track and movable along the track between a closed position and an open position;
• and a closed loop cable closure system mounted on the vehicle frame and including a cable drive with a front cable drive pulley having a large diameter cable groove and a small diameter cable groove mounted on the vehicle frame for rotation about an axis, a rear cable drive pulley having a large diameter cable groove and a small diameter cable groove mounted on the vehicle frame for rotation about an axis, a motor that drives the front and rear cable drive pulleys in one direction to open the sliding door and in another direction to close the sliding door, a front cable that extends from the front cable drive pulley to the sliding door, a rear cable that extends from the rear cable drive pulley to the sliding door, a fixed idler roller mounted on the vehicle frame and spaced from the rear cable drive pulley, a spring biased roller mounted on the frame between the rear cable drive pulley and the fixed idler roller and spring biased into contact with the rear cable to apply tension to the rear cable and wherein the fixed idler roller and the spring biased roller are mounted in positions which provide a cable tension when the rear cable is driven by the large diameter cable groove that is substantially equal to the cable tension when the rear cable is driven by the small diameter cable groove.

A sliding door opening and closing system for a vehicle including a vehicle frame;

• sliding door tracks attached to the vehicle frame;
• a sliding door supported by the sliding tracks and guided by the sliding door tracks between a closed position and a fully open position;
• and a closed loop cable closure system mounted on the vehicle frame and including a cable drive with a front cable drive pulley having a large diameter cable groove and small diameter cable groove mounted on the vehicle frame for rotation about an axis, a rear cable drive pulley having a large diameter cable groove and a small diameter cable groove mounted on the vehicle frame for rotation about an axis, a motor that drives the front and rear cable drive pulleys in one direction to open the sliding door and in another direction to close the sliding door, a front cable that extends from the front cable drive pulley to the sliding door and is driven by the small diameter cable groove on the front cable drive pulley when the sliding door is in the forward portion of the sliding door track and is driven by the large diameter cable groove on the front cable drive pulley when the sliding door is in the rear portion of the sliding door track, a rear cable that extends from the rear cable drive pulley to the sliding door and is driven by the small diameter cable groove on the rear cable drive pulley when the sliding door is in the forward portion of the sliding door track and is driven by the large diameter cable groove on the rear cable drive pulley when the sliding door is in the rear portion of the sliding door track, a first fixed idler roller mounted on the vehicle frame and spaced from the front cable drive pulley, a first spring biased roller mounted on the frame between the front cable drive pulley and the first fixed idler roller and spring biased into contact with the front cable and wherein the first fixed idler roller and the first spring biased roller are mounted in positions which provide a cable tension when the front cable is driven by the large diameter cable groove on the front cable drive pulley that is substantially equal to the cable tension when the front cable is driven by the small diameter cable groove on the front cable drive pulley, and a second fixed idler roller mounted on the vehicle frame and spaced from the rear cable drive pulley, a second spring biased roller mounted on the frame between the rear cable drive pulley and the second fixed idler roller and spring biased into contact with the rear cable and wherein the second fixed idler roller and the second spring biased roller are mounted in positions which provide cable tension when the rear cable is driven by the large diameter cable groove on the rear cable drive pulley that is substantially equal to the cable tension when the rear cable is driven by the small diameter cable groove on the rear cable drive pulley.