Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.

Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.

Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.

Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.

Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.

Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.

Abstract: A movable barrier operator includes an absolute position detector which provides a unique value for each position of the barrier along its path of travel. The absolute position detector employs multiple binary serial streams and one multiple clock stream. After the first five cycles of the clock stream, the binary streams can be decoded by a processor to produce an absolute position. Every clock edge produces a new absolute position along the path of travel.

Abstract: A method of programming a controller for a movable barrier operator includes enabling and disabling an input device within a predetermined period of time, a predetermined number of times. This sequence of short activations of an input device, such as a switch on a wall unit, puts the controller in a learn mode or a programmed state. Thereafter, the controller is responsive to learn any of the various routines that can be programmed for the movable barrier operator, such as transmitter code, limits of travel, force settings, and so on.

Abstract: A jack shaft garage door operator for opening and closing a movable garage door has a drive containing an electric motor. A rotatable jack shaft is connected to the drive unit to be driven thereby. A pull-up cable drum is connected to and driven by the jack shaft. A pull-up cable extends from the drum about which it is wound and connects to a bottom part of the garage door to raise the door. A pivoting arm is mounted near the jack shaft and provides tension to the cable. A shaft lock hub mounted on the jack shaft is engaged and locked by the arm if the tension in the cable drops. A stop is mounted on the garage door for engagement by the movable arm in the event that the door is opened without the cable being drawn in the cable drum.

Abstract: An adjustable limit switch mechanism for controlling the operation of an electric motor of a garage door opener over a selected range of movement including a motor driven threaded shaft supporting at least one switch actuator which is adjustably positionable and restrained from rotary movement while being axially translated by rotation of the shaft. A limit switch is mounted adjacent the threaded shaft so as to be actuated as the switch actuator is translated axially on the shaft.

Abstract: A chain guide is provided for the otherwise unsupported upper run of the endless roller chain of a motor-driven garage door operator. With the chain loop in a vertical plane, the chain guide takes the form of a trough having at its bottom an upstanding central ridge which supports the chain by its rollers and with the links clear of contact with the floor and sides of the trough. The chain guide is supported indirectly by the trackage of the door operator, being mounted upon the fixed rail spacer of one form and carried upon the movable trolley of the other.

Abstract: A jack shaft garage door operator for opening and closing a movable garage door has a drive containing an electric motor. A rotatable jack shaft is connected to the drive unit to be driven thereby. A pull-up cable drum is connected to and driven by the jack shaft. A pull-up cable extends from the drum about which it is wound and connects to a bottom part of the garage door to raise the door. A pivoting arm is mounted near the jack shaft and provides tension to the cable. A shaft lock hub mounted on the jack shaft is engaged and locked by the arm if the tension in the cable drops. A stop is mounted on the garage door for engagement by the movable arm in the event that the door is opened without the cable being drawn in the cable drum.