Abstract: An adjustable drive mechanism for reciprocating a pair of sealing jaws in a packaging apparatus and controlling the stroke length includes a drive belt operatively connected to move the carriage and jaws in the up and down direction. A movable pulley assembly interconnects the drive belt ends and is attached to a working arm oscillated by a linkage arrangement. The linkage arrangement includes a rocker oscillated with a crank and connecting rod. A control link pivotally connected to the rocker completes the linkage and deflects to allow raising of the working arm and driving the sealing jaws on a downward draw stroke. The upper end of the control link constitutes an adjustable pivot to vary the degree of movement imparted by the working arm to the drive belt. The adjustable pivot is carried by an annular adjustment ring mounted within an annular guide groove of a mounting plate.

Abstract: A door mechanism for controlling flow of loose products, such as potato chips, from a scale hopper in a packaging machine comprises a hinged door, a spring biasing the door towards its closed position, an arm attached to the door, a cam follower carried by the arm, and a cam acting in combination with the cam follower to force the door open against the influence of the spring. The cam is mounted independently of the scale hopper and the cam follower is not in contact with the cam while product is being weighed in the scale hopper. When weight has been made, the cam is rotated in response to signals generated by the weighing scale. The profile of the cam is such as to rapidly open and close the door for dumping and provides smooth vibration-free operation. The slope of the cam lobe portion during opening of the door provides an uplifting scale restoring force so that the scale is immediately returned to zero weight in readiness for the next cycle.