Cable drum cable tensioner and methods in a movable barrier system
A movable barrier system for operating a movable barrier may include a torsion tube configured to rotate and a cable drum comprising a cable connectable to the movable barrier. The cable drum may be configured to rotate relative to the torsion tube. The movable barrier system may further include a sensor configured to detect the angular displacement or a force between the torsion tube and the cabled drum and send a signal when the angular displacement or the force changes. The movable barrier system may further include a controller in communication with the sensor and configured to stop rotation of the torsion tube in response to the signal.
1 . A movable barrier system for operating a movable barrier comprising:
a torsion tube configured to rotate;
a cable drum on the torsion tube, the cable drum configured to rotate relative to the torsion tube;
a cable disposed on the cable drum and configured to connect to the movable barrier;
a sensor which detects an angular displacement between the rotation of the torsion tube and the rotation of the cable drum or a force between the torsion tube and the cable drum and sends a signal when the angular displacement or the force changes; and
a controller in communication with the sensor and configured to stop rotation of the torsion tube in response to the signal.
2 . The movable barrier system of claim 1 , wherein the sensor is configured to detect the angular displacement and configured to send the signal when the angular displacement exceeds a threshold.
3 . The movable barrier system of claim 1 , further comprising an anchor assembly and a displacement coupler, the anchor assembly comprising an anchor and a bearing, the anchor being coupled to the torsion tube in a manner that the anchor, the bearing, and the torsion tube rotate with an about equal angular velocity, and the displacement coupler configured to oppose rotation of the cable drum when the cable drum rotates relative to the anchor, the bearing, and the torsion tube.
4 . The movable barrier system of claim 2 , wherein the sensor is configured to send an initial signal to the controller to rotate the torsion tube, the initial signal being transmitted from the sensor to the controller unless the angular displacement exceeds the threshold.
5 . The movable barrier system of claim 1 , wherein the signal is further configured to communicate at least one angular displacement value to the controller.
6 . The movable barrier system of claim 3 , further comprising a track, the track being coupled to the cable drum in a manner that the track rotates with an about equal angular velocity as the cable drum, and the sensor configured to determine the angular displacement based on a position of the sensor and the track.
7 . A movable barrier system for operating a movable barrier comprising:
a torsion tube configured to rotate in a first direction;
a cable drum on the torsion tube, the cable drum configured to rotate in the first direction and a second direction and configured to rotate relative to the torsion tube in a manner that changes an angular displacement between the torsion tube and the cable drum;
a cable disposed on the cable drum and configured to connect to the movable barrier;
a displacement coupler configured to oppose rotation of the cable drum in the second direction when the cable drum rotates relative to the torsion tube; and
a sensor which communicates a signal to a controller when the angular displacement between the rotation of the torsion tube and the rotation of the cable drum or a force between the torsion tube and the cable drum changes.
8 . The movable barrier system of claim 7 , further comprising a mechanical limit configured to cause the cable drum to rotate in the first direction with an about equal angular displacement as the torsion tube.
9 . The movable barrier system of claim 7 , further comprising an anchor assembly, the anchor assembly comprising an anchor and a bearing, the anchor being coupled to the torsion tube in a manner that the anchor, the bearing, and the torsion tube rotate with an about equal angular velocity, the bearing being configured to allow the cable drum to rotate in the second direction.
10 . The movable barrier system of claim 7 , wherein the sensor is configured to communicate the signal when the angular displacement exceeds a threshold.
11 . The movable barrier system of claim 9 , wherein the displacement coupler further comprises a spring coupled to the cable drum and the anchor assembly.
12 . The movable barrier system of claim 7 , further comprising a motor configured to cause the torsion tube to rotate in the first direction.
13 . The movable barrier system of claim 9 , further comprising at least one set screw securing the anchor to the torsion tube.
14 . A method for operating a movable barrier in a movable barrier system, the method comprising:
providing a torsion tube and a cable drum, the cable drum being positionable on the torsion tube;
rotating the torsion tube and the cable drum in a first direction with an about equal angular velocity;
allowing the angular velocity of the cable drum to decrease in a manner that an angular displacement between the rotation of the torsion tube and the rotation of the cable drum increases; and
selectively communicating a signal from a sensor to a controller to stop movement of the movable barrier when the angular displacement reaches a threshold.
15 . The method of claim 14 , further comprising;
determining the angular displacement with the sensor; and
communicating the signal with the sensor when the angular displacement reaches the threshold.
16 . The method of claim 14 , further comprising:
providing an anchor assembly and a displacement coupler, the anchor assembly comprising an anchor and a bearing;
coupling the anchor to the torsion tube in a manner that the anchor, the bearing, and the torsion tube rotate with an about equal angular velocity; and
coupling the displacement coupler to the cable drum and the anchor in a manner that the displacement coupler is configured to oppose rotation of the cable drum in a second direction when the cable drum rotates relative to the torsion tube, the second direction being opposite the first direction.
17 . The method of claim 15 , further comprising communicating an initial signal from the sensor to the controller to rotate the torsion tube, the initial signal being transmitted from the sensor to the controller unless the angular displacement reaches the threshold.
18 . The method of claim 14 , further comprising communicating with the signal at least one angular displacement value to the controller.
19 . The method of claim 14 , further comprising:
providing an anchor assembly comprising an anchor and a bearing, the anchor being coupled to the torsion tube in a manner that the anchor, the bearing, and the torsion tube rotate with an about equal angular velocity;
coupling a track to the cable drum in a manner that the track rotates with an about equal angular velocity as the cable drum; and
configuring the sensor to determine the angular displacement based on a position of the sensor and the track.
20 . The movable barrier system of claim 1 , wherein the sensor is positioned on the cable drum and is configured to send the signal, the signal indicating the cable drum is rotating at a different angular velocity than the torsion tube.