Patent ID: 6948292

Claim:
A machine for making filter bags ( 1 ) containing an infusion product, the machine comprising the following, arranged in succession: a unit ( 53 ) for preparing and feeding the materials used to make the filter bags ( 1 ), in which: a web ( 17 ) of filter paper bearing a layer of heat-activated glue, a continuous thread ( 31 ) and a row of tags ( 6 ) are fed in coordinated fashion and associated with each other, the filter paper web ( 17 ) and the thread ( 31 ) moving continuously through the feed unit ( 53 ), while the tags ( 6 ) and the thread ( 31 ) are associated with each other in rhythmical sequence at the ends of thread portions ( 7 ) which: lie lengthwise relative to the filter paper web ( 17 ); have a predetermined length; and are delimited at their ends by first loops ( 10 ) made in the thread ( 31 ) itself; a metering assembly ( 54 ) which places charges ( 19 ) of the infusion product on the filter paper web ( 17 ); a forming unit ( 55 ), a dividing unit ( 56 ) and a cutting unit ( 57 ), in the forming unit ( 55 ), the web ( 17 ) of filter paper being folded onto itself in such a way as to form a tube ( 34 ), inside which the metering assembly ( 56 ) places charges ( 19 ) of the infusion product, the tube ( 34 ) then being gradually closed by sealing it along its longitudinal edges ( 18 ); in the dividing unit ( 56 ), pairs of sealed transversal joins ( 4 , 5 ) being made in the tube ( 34 ) upstream and downstream of each tag ( 6 ), these transversal sealed joins ( 4 , 5 ) dividing the tube ( 34 ) into a succession of substantially flattened containment chambers ( 2 ) containing corresponding charges ( 19 ) of the infusion product; in the cutting unit ( 57 ), the tube ( 34 ) being cut into successive lengths, lying flat and lengthwise and each constituting the containment chamber ( 2 ) of a filter bag ( 1 ).