Collapsible track undercarriage for installation and tensioning
View Patent ↗A track frame or undercarriage is made to support a rubber track on suitable guide rollers. A tensioning roller is provided as one of the guide rollers on the interior of the track and is mounted on a pivoting bracket. The pivoting bracket moves the tensioning roller to a working position for creating tension in the track. An actuator provides a known force on the pivoting bracket to move the tensioning roller to its working position, using a controlled pressure applied to the actuator. Drive sprockets for the track are mounted onto a drive case that is mounted to the frame through pivoting linkages such that the drive case and the drive sprocket can be held in a working position and retracted away from the track. The position of the tensioning roller is maintained within set limits of retractions during use, by providing a stop to limit the amount that the tensioning roller can retract.
1. A drive track support for a vehicle comprising a support frame extending in fore and aft direction, a plurality of guide rollers on the support frame for guiding an endless track, said guide rollers including a moveable tension roller positioned to move at an acute angle relative to the fore and aft direction to create a tension in an endless track on the guide rollers along a vector at an acute angle relative to the fore and aft direction;
wherein there is a track drive wheel for driving the endless track at an end of the track frame opposite from the tension roller, a drive case having an output shaft mounting and driving the track drive wheel, and a linkage for moveably supporting the drive case relative to the track frame to permit the drive case and track drive wheel to move to a retracted position reducing tension on the endless track.
2. The drive track support of claim 1 , wherein said tension roller is mounted on a bracket, a pivot for connecting the bracket to the track frame, and a control actuator for moving the bracket about the pivot to provide the tension with a force acting along the vector.
3. The drive track support of claim 2 , wherein said control actuator comprises a hydraulic actuator, and a hydraulic circuit providing a known, substantially uniform pressure to the actuator to maintain a known tension in the endless track.
4. The drive track support of claim 3 , wherein said hydraulic circuit has a pressure relief valve to control maximum pressure exerted on the actuator.
5. The drive track support of claim 2 and a stop member to limit the amount the bracket can move about its pivot in a direction for releasing tension in the endless track.
6. The drive track support of claim 1 , wherein said drive case is supported in a releasable fixed position for driving the endless track with the track drive wheel, and a bracket for releasably holding the drive case in its fixed position, and being releasable to permit the drive case to move to its retracted position.
7. The drive track support of claim 1 , wherein said linkage supporting said drive case comprises a pair of pivoting linkages, said pivoting linkages each having first ends pivotally mounted to the support frame, and second ends pivotally mounted to the drive case.
8. A drive track support for a vehicle comprising:
a support frame for supporting and mounting an endless track frame for the vehicle;
a track drive wheel for driving an endless track;
a drive case having an output shaft mounting and driving the track drive wheel; and
a linkage for moveably supporting the drive case relative to the endless track frame to permit the drive case and the track drive wheel to move to a retracted position reducing tension on the endless track;
wherein the linkage supporting the drive case comprises a pair of pivoting linkages, the pivoting linkages each having first ends pivotally mounted to the support frame, and second ends pivotally mounted to the drive case.
9. The drive track support of claim 8 , wherein the drive case is supported in a releasable fixed position for driving the endless track with the track drive wheel, and further comprising a bracket for releasably holding the drive case in its fixed position, and being releasable to permit the drive case to move to its retracted position.
10. A support frame for supporting and mounting an endless track frame for a vehicle, the support frame extending in fore and aft direction, guides on the support frame for guiding an endless track, including a guide roller, a drive on the endless track frame to drive the endless track in a path around the endless track frame, an arm pivoted to the support frame at one end and having the guide roller mounted at an opposite end, the arm being movable from a working position to a retracted position, an actuator to move the arm between its retracted position and working position, the guide roller engaging the track to create a tension in the track with the arm in its working position;
wherein said actuator comprises a hydraulic actuator, and a hydraulic circuit providing a known, substantially uniform pressure to the hydraulic actuator to maintain a known tension in the track; and
a removable stop member to limit the amount the arm can pivot about its pivot from its working position toward its retracted position, said stop being removable to permit the arm to move to its retracted position;
wherein there is a track drive wheel for driving the track on the support frame at a position spaced from the guide roller, a drive case having an output shaft, a track drive wheel drivably mounted on the output shaft, and a linkage for moveably supporting the drive case relative to the support frame to permit the drive case and track drive wheel to move to a retracted position reducing tension on the track.
11. The support frame of claim 10 , wherein said drive case is supported in a releasable fixed position for driving the endless track with the track drive wheel, and a bracket for releasably holding the drive case in its fixed position, and being releasable to permit the drive case to move to its retracted position.
12. The support frame of claim 10 , wherein the arm is pivotally mounted on a support bracket, the removable stop comprising a removable pin carried on the arm, the pin engaging a portion of the support bracket as the arm moves from its working position toward its retracted position.