Stacking wheels with superimposed retarder action

Claim 1

In combination with a thermoplastic film converting machine having a working surface and a work station disposed therealong, means at the input end of said working surface for receiving a supply web of thermoplastic film to be treated, draw roll means for controllably moving said supply web from said supply to said work station, thermal treating means disposed at said work station for intermittently sealing and severing said thermoplastic web at spaced locations along the length of said web to prepare thermoplastic film products therefrom, product conveyor means for removing thermoplastic film products from said thermal treating means and conveying said products to a product receiving station, and a product receiving station disposed at the output end of said conveyor means for receiving thermoplastic film products; corrugating wheels disposed along said conveyor means between said thermal treating means and said product receiving station for transferring said thermoplastic film products from said conveyor means to said product receiving station, said corrugating wheels comprising: a. a first and second plurality of disc means disposed in spaced relationship along respective first and second generally parallelly disposed mounting shafts, with said first and second plurality of disc means being arranged in spaced staggered relationship along said mounting shafts, each of said mounting shafts being arranged for axial rotation and having drive means for imparting controlled rotation thereto, said first mounting shaft being disposed above the plane of said product conveyor means and said second shaft being disposed below said product conveyor plane, and with the peripheral edges of said first and second plurality of disc means overlapping to present a generally sinusoidal transverse profile; b. said drive means being arranged to impart rotary motion to said mounting shafts in timed relationship to the movement of thermoplastic film products therethrough, with said drive means normally rotating said mounting shafts to drive said disc means at a peripheral rate generally equal to the linear speed of said conveyor means, and with speed control means arranged to intermittently and momentarily retard the rotational velocity of said mounting shafts and said disc means at a point in time generally coincidential with the passage of the trailing edge of each thermoplastic film product through said disc means and to thereafter restore said normal rotational velocity upon completion of passage of each thermoplastic film product through said disc means.