Abstract: This invention relates to a film winding and rewinding machine characterized by a single unidirectional motor being used in cooperation with a pair of electrically-actuated clutch/brake units and a suitable power train to actuate the take-up reel in either direction. It also encompasses an automatic mechanism responsive to the tail end of the film leaving the hub of the supply reel to shut off power to the motor and stop the take-up reel in both the FORWARD and REVERSE modes. It further envisions using the drag of the friction brake in whichever of the clutch/brake units is actuated into its clutch mode to apply a variable tension to the film coming off of the reel functioning in the capacity of the supply reel.

Abstract: This invention relates to an improvement upon the film winding and rewinding apparatus forming the subject matter of my copending application Ser. No. 666,187 filed Oct. 29, 1984, by a replacement of its former manually-shifted electrochemical reversing system for changing from a so-called "A-wind" to a "B-wind" with an electromagnetic one employing a pair of electromagnetic clutches on parallel counterrotating output shafts operatively linked together with a belt and pulley power transfer mechanism which cooperates with the clutches to impose a drag upon the supply reel regardless of which direction it is being turned by the power supplied to the take-up reel. The invention also encompasses an electromechanical circuit in which an idler spool responsive to the tension in the film passing between the supply and take-up reels actuates a potentiometer which, in turn, lessens the drag on the supply reel as the tension increases.