Abstract: A method for forming a top seal on a carton being conveyed along a processing path on a form, fill and seal packaging machine using a top sealer including opposing sealing jaws is provided. The carton includes top fin panels configured for sealing to one another to form a top seal. The method includes actuating a first control valve to provide communication between a first pressurized fluid source and a first port of an actuator for moving the actuator toward a first position. The actuator is operatively connected to the sealing jaws to move the sealing jaws in a clamping direction while moving toward the first position. A second control valve is actuated to inhibit fluid escape from the actuator through a second port of the actuator to inhibit movement of the sealing jaws in the clamping direction.

Abstract: An apparatus for effecting closure of an open end of a carton blank by placing portions of the carton blank into overlying relationship to one another is provided. The apparatus includes a cam that rotates about an axis of rotation and a cam lever that is operatively connected to the cam. The cam lever is used to convert rotating motion of the cam into linear motion to define a first stroke distance. A pressure pad is mounted for movement toward and away from the portions of the carton blank. The pressure pad is capable of being moved in response to input provided by the cam to define a second stroke distance. An air spring is mechanically linked to the cam lever and the pressure pad such that the air spring absorbs a portion of the first stroke distance.