Patent ID: 7305808

Claim:
A packaging machine comprising: a cylindrical chute; means for bending an elongated bag-making film into a tubular form around said chute by mutually overlapping side edges of said film; a heater unit for longitudinally sealing said mutually overlapping side edges of said film; heater driving means for moving said heater unit between a sealing position at which said heater unit contacts said film and a retracted position at which said heater unit is separated from said chute; a motor for moving said heater unit between a work area that includes said sealing position and said retracted position and a non-work area that is farther removed from said chute than said work area; and a force-controlling air cylinder for controlling compressive force with which said heater unit at said sealing position compresses said film against said chute by having air of a specified pressure supplied thereto; wherein said force-controlling air cylinder and said heater unit are affixed to one end of an elongated arm member and said heater driving means includes a heater-moving air cylinder which serves to move said arm member.