Continuous thread tension indicating drive roller

Claim 1

A YARN MOVING APPARATUS ADAPTED FOR INDICATING SIMULTANEOUSLY THE TENSION IN THE YARN, SAID APPARATUS COMPRISING: A YARN MOVEMENT CONTROL ROLL; AN ELECTRIC MOTOR OPERATIVELY CONNECTED TO SAID TOLL, TO CONTROL THE SPEED OF THE SAME, THE FRAME OF SAID MOTOR AND SAID DRIVING ROLL BEING JOINTLY SUSPENDED THROUGH AN ESSENTIALLY FRICTIONLESS CONTACT, ON A STATIONARY SUPPORT FOR FREE OSCILLATION ABOUT AN AXIS COINCIDENT WITH THE AXIS OF THE MOTOR; AND INDICATOR MEANS RIGIDLY CONNECTED TO THE FRAME OF THE MOTOR FOR JOINT OSCIALLATION THEREWITH WHEREBY TO INDICATE DEVIATIONS OF THE MOTOR FRAME FROM AN ASSUMED ZERO POSITION AS A RESULT OF VARIATIONS IN THE TORQUE IMPOSED ON THE ROLL, SAID INDICATOR MEANS COMPRISING: (A) A PHOTOCELL ARRANGEMENT, INCLUDING A BEAM OF LIGHT, SUPPORTED IN A FIXED POSITION RELATIVE TO THE FRAME OF THE MOTOR; AND (B) A THREAD-LIKE ELEMENT WEIGHTED TO MAINTAIN AND ESSENTIALLY CONSTANT VERTICAL POSITION, SAID THREAD-LIKE ELEMENT BEING SUPPORTED FOR EFFECTIVELY INTERRUPTING SAID BEAM OF LIGHT WHEN THE POTOCELL ARRANGEMENT IS IN THE NULL POSITION AND FOR PASSING SAID LIGHT BEAM THROUGH WHEN THE INDICATING DEVICE, TOGETHER WITH THE MOTOR, HAVING DEVIATED FROM SAID NULL POSITION.