Patent ID: 7748201

Claim:
A form-and-seal unit for producing aseptic sealed packages of a pourable food product from a tube of packaging material filled with the food product and fed along a vertical path, the unit comprising: two spaced apart guides; two forming assemblies movable along the spaced apart guides; each forming assembly comprising a pair of jaws having sealing means for sealing the tube of packaging material and movable between an open position and a closed position in which the sealing means cooperate with the tube of packaging material; a forming flap carried by each jaw and having a respective half-shell forming portion, the forming flaps of each pair of jaws being movable between a withdrawn position in which they do not cooperate with the tube and a forward position in which the respective half-shell forming portions surround the tube in the closed position of the respective jaws to form a cavity of predetermined volume a fixed cam formed as a flat plate; cam-followers carried by the forming flaps, the cam-followers contacting and moving along respective work profiles of the fixed cam during operation of the unit to control approach movement of the forming flaps from the withdrawn position to the forward position; the work profiles of the fixed cam comprising a first pair of work profiles and a second pair of work profiles which differ in size from one another, the work profiles forming the first pair of work profiles being spaced apart from one another in a width-wise direction of the fixed cam, the first pair of work profiles being offset from the second pair of work profiles in a thickness direction of the flat plate forming the fixed cam, with the first pair of work profiles being contacted by the cam followers of two forming flaps of a first type to control the approach movement of the two forming flaps of the first type towards each other and towards the tube, the second pair of work profiles being contacted by the cam followers of two forming flaps of a second type, which differ in size relative to the two forming flaps of the first type, to control the approach movement of the two forming flaps of the second type towards each other and towards the tube.