Patent ID: 7204883

Claim:
A feed unit for strip wrapping material comprising: a gumming device acting on the strip; means by which to support the gumming device; a gumming roller and a transfer roller forming part of the gumming device, rotatable about horizontal and parallel axes, each roller being carried and driven by a respective drive shaft, and engaging one with another along an area of tangential contact coinciding with a straight line generator common to the two rollers in such a way as to create a trough between their respective cylindrical surfaces, extending adjacent to the area of tangential contact and serving to hold a predetermined quantity of an adhesive substance; a circuit, through which to circulate a fluid controlling the temperature of at least the gumming roller or of the transfer roller of the gumming device, said circuit comprising: an inlet duct and an outlet duct admitting and releasing the fluid, a flow branch, associated with at least one of the two rollers, which departs from the respective inlet duct and passes through a first duct extending along the respective drive shaft, through a first valve element, then through a second duct extending along the roller associated to the drive shaft and including a plurality of annular chambers formed within the selfsame roller, and a return branch which departs from the annular chambers and passes through a third duct extending along the selfsame roller, through a second valve element, then through a fourth duct extending along the selfsame drive shaft and terminating at the outlet duct.