Method and apparatus for making double groove pulleys

A machine for forming a pulley having a plurality of pulley grooves of given cross section from a pulley blank in the form of a cup, each groove being defined by pulley wall means connected through the root of the groove and each groove being separated from an adjacent groove by a land, comprising axially movable members for engaging said blank adjacent opposed axial ends thereof, means to axially advance at least one of said axially movable members toward the other to a final apposition at which they define a die cavity, first and second rotatably mounted roll die means, said first roll die means including a first forming roll translatable toward the longitudinal axis and the outer sidewall of the cup along a path defined by a first imaginary line connecting a center of rotation of said forming roll and said longitudinal axis and having a periphery adapted to roll form the periphery of the blank to a desired configuration, said second roll die means having a second forming roll positioned between said axially movable members, being translatable away from the longitudinal axis and toward the inner sidewall of the cup along a path defined by a second imaginary line connecting the center of rotation of said second roll die means and said longitudinal axis, and having a periphery adapted to complement the periphery of said first roll die means and to roll form the periphery of the blank to said desired configuration, said first and second imaginary lines being at an angle of greater than 0.degree. with respect to each other, means to establish relative rotation between said pulley blank and said forming rolls, first roll die moving means to advance said first roll die means from a retracted position toward said longitudinal axis to its forming position at which it defines a die cavity corresponding to further portions of a desired configuration, second roll die moving means to advance said second roll die means away from said longitudinal axis toward the inner sidewall of the cup and to said forming position at which it and said first roll die means together define said further portions of said desired configuration.