Patent ID: 7976656

Claim:
A method of gumming a web of wrapping material in a filter tip attachment machine, using a gumming device that comprises: a gumming roller and a transfer roller rotatable about axes disposed horizontal and parallel one with another, turning in opposite directions and engaged in mutual contact at a zone of tangency coinciding with a shared straight line generator, thereby creating a trough between the respective cylindrical surfaces of the rollers at the zone of tangency, in which to hold a predetermined quantity of adhesive; a feed circuit delivering the adhesive to the trough; a drive mechanism by which the rollers are set in rotation about their respective axes; a control unit to which the feed circuit and drive mechanism are interlocked; and a gumming station at which the gumming roller revolves tangentially to the web of wrapping material, including the steps, implemented in an event of the machine being affected by a stoppage, of: suspending delivery of the adhesive; distancing the web of wrapping material from the gumming roller; reversing the directions of rotation of the rollers, respectively, relative to the direction of rotation during normal operation, such that the trough is emptied gradually of adhesive.