Packaging machine for production of bags of tubular material

Claim 1

IN A PACKAGING MACHINE OF THE TYPE IN WHICH A SERIES OF FILLED AND SEALED MERCHANDISE PACKAGES ARE FORMED FROM A TUBE OF HEAT-SEALABLE MATERIAL DRAWN OVER A FILLING PIPE THROUGH WHICH THE MERCHANDISE IS INTRODUCED INTO THE TUBE: A PAIR OF HEATED JAWS ON OPPOSITE SIDES OF THE TUBE AND MOVABLE TOWARD AND AWAY FROM EACH OTHER IN A DI-RECTION TRANSVERSE TO THE LONGITUDINAL AXIS OF THE TUBEE BETWEEN A CLOSED AND OPEN POSITION, SAID JAWS WHENN CLOSED FORMING A TRANSVERSE SEAL ON SAID TUBE, A PNEUMATIC PISTON-CYLINDER ARRANGEMENT FOR EFFECTING SAID TRANSVERSE MOVEMENT OF SAID JAWS, AND MEANS FOR MOVING SAID JAWS BACK AND FORTH IN A LONGITUDINAL DIRECTION WHEN SAID JAWS ARE IN CLOSED CONDITION FOR ADVANCING THE TUBE THROUGH THE MACHINE, SAID MEANS INCLUDING A VERTICALLY MOVABLE POST, A PLATFORM MOUNTED ON THE UPPER END OF SAID POST, A PAIR OF SPACED-APART VERTICAL WINGS CARRIED BY SAID PLATFORM SAID WINGS BEING ARRANGED ON OPPOSITE SIDES OF THE TUBULAR MATERIAL AND EACH OF SAID WINGS CARRYING A PNEUMATIC PISTON-CYLINDER DEVICE, A PAIR OF LEVERS PIVOTALLY MOUNTED INTERMEDIATE THEIR ENDS ON EACH OF SAID WINGS, ONE END OF ONE OF SAID LEVERS BEING PIVOTALLY CONNECTED TO ONE OF SAID JAWS AND THE CORRESPONDING END OF THE OTHER LEVER BEING PIVOTALLY CONNECTED TO THE OTHER JAW, AND A LINK PIVOTALLY CONNECTED BETWEEN THE OPPOSITE END OF EACH OF SAID LEVERS AND SAID PISTON-CYLINDER DEVICE, SAID LEVERS AND LINKS BEING SO ARRANGED THAT UPON MOVEMENT OF THE PISTONCYLINDER DEVICE IN ONE DIRECTION SAID LINKS TEND TO BECOME ALIGNED AND CLOSE SAID JAWS AND UPON MOVEMENT OF SAID DEVICE IN THE OPPOSITE DIRECTION SAID LINKS MOVE OUT OF ALIGNMENT AND OPEN SAID JAWS.