Opposed arm web accumulator

A web accumulator comprising:

• a base,
• first and second axle arranged with their axes in parallelism and journaled for turning relative to said base, the axes of the axle shafts being spaced from each other along a common centerline,
• first and second arms fastened to said axle shafts, respectively, for swinging in spaced apart parallel planes in response to turning of said axles shafts, said arms extending in generally opposite directions from the respective shaft axes,
• first and second wheel means fastened to said first and second axle shafts, respectively,
• a flexible member formed in a closed loop around both of said wheel means and engaged with said wheel means for turning said wheel means and the arms with said axle shafts concurrently through the same angle in response to translation of said flexible member resulting from one axle shaft being driven rotationally,
• a torque arm fastened to one axle shaft and having a curved profile surface whose radius of curvature about the axis of said axle shaft varies over the length of the surface,
• a force producing actuator,
• a flexible element connected between said actuator and said curved surface for said flexible element to be maintained in tangential contact with said curved surface at points along said surface having radii of different lengths as said torque arm is rotated due to tension developed in said flexible element resulting from actuation of said actuator, rotation of said torque arm driving said one axle shaft rotationally to cause said one arm to swing through an angle away from one side of said centerline and the other arm to swing away through a corresponding angle from the other side of said centerline until the arms attain a predetermined maximum angle,
• changes in the moment of force defined by the length of the radius at the point of tangency times the tension in the flexible element causing the torsional force on the axle shaft and first and second arms to vary in correspondence with the angle of the arms with respect to said centerline,
• a web infeed roller rotatable on the first axle shaft and web outfeed roller rotatable on the second axle shaft,
• a series of spaced apart additional rollers supported on each arm, the rollers on one arm extending from the plane in which the one arm swings toward the plane in which the other arm swings, the ends of the rollers opposite from the arm on which they are supported being free to provide for a web being looped around rollers on opposite arms in succession from said web infeed roller to said web outfeed roller such that the maximum length of web accumulated in said accumulator occurs when arms are swung to their said maximum angle.