Patent ID: 8004224

Claim:
A safety device for a movable barrier to stop or initiate a reversing movement during closing or opening of the barrier, the barrier being actuated by a motor and being movable along an operational travel path, the device comprising: a first and a second part, the second part rotatably connected to the first part and being rotatable relative to the first part along a rotational travel path limited to less than 360 degrees, the first part being fixed relative to a movement of the movable barrier, the second part being joined to the motor of the movable barrier and being independently rotatable with respect to the action of the motor of the movable barrier; a detecting means for detecting along the rotational travel path the relative position of first and second parts; a processing unit for processing data detected by the detecting means and for generating position data defining a positional relationship between the first and second parts that correlate to position of the movable barrier along the operational travel path, the processing unit being able to utilize the generated position data for controlling the motor when the generated position data indicates a position of the movable barrier along the operational travel path exceeding a predetermined safety position; wherein the first part comprises a cavity, the second part being kinematically connected to the movable barrier and coaxially connected with rotational movement to the first part in the cavity.