Method and machine for making tubular container bodies

Claim 1

AN APPARATUS FOR FORMING A TUBULAR CONTAINER BODY FROM A BLANK OF RELATIVELY THIN FLEXIBLE SHEET MATERIAL HAVING A SEAL FORMING MATERIAL ON A SIDE MARGINAL PORTION WHICH IS ADAPTED TO BE OVERLAPPED WITH THE OPPOSITE SIDE MARGINAL PORTION SO AS TO FORM A LAPPED SEAM, SAID APPARATUS COMPRISING AN ELONGATE CYLINDRICAL FORMING MANDREL DISPOSED IN A GENERALLY HORIZONTAL POSITION, A BLANK SUPPLY MAGAZINE ADJACENT AN ENTRANCE END OF THE MANDREL, MEANS FOR FEEDING SUCCESSIVE BLANKS FROM THE SUPPLY MAGAZINE, A BLANK ADVANCING CONVEYOR HAVING MEANS THEREON FOR ENGAGING THE TRAILING EDGE OF EACH SUCCESSIVE BLANK AND FOR ADVANCING THE SAME TO SAID MANDREL, MEANS ALONG THE BLANK FEED CONVEYOR FOR BENDING A SIDE MARGIN OF EACH SUCCESSIVE BLANK TO IMPART THERETO A SLIGHT CURVATURE, AN OVERHEAD CONVEYOR MOUNTED ON END SUPPORTS WHICH ARE DISPOSED AT OPPOSITE ENDS OF SAID FORMING MANDREL WITH THE BOTTOM RUN OF THE CONVEYOR TRAVELING IN A GENERALLY PARALLEL PATH IMMEDIATELY ABOVE THE TOP SURFACE OF THE MANDREL, SPACED BLOCKS ON SAID OVERHEAD CONVEYOR HAVING OUTWARDLY FACING CURVED SURFACES CONFORMING GENERALLY TO THE CURVATURE OF SAID MANDREL AND MEANS RESILIENTLY MOUNTED ON SAID BLOCKS FOR ENGAGING THE TRAILING EDGE OF EACH SUCCESSIVE BLANK AS IT IS ADVANCED TO THE LEADING END OF THE BLANK FEED CONVEYOR AND FOR ADVANCING SAID BLANK ALONG THE TOP SURFACE OF SAID MANDREL, THE CURVED FACES OF SAID BLOCKS SERVING TO PRELIMINARILY SHAPE EACH SUCCESSIVE BLANK AND START THE FOLDING THEREOF ABOUT THE TOP SURFACE OF THE MANDREL, HEATING MEANS ADJACENT THE MANDREL FOR ACTIVATING THE SEAL FORMING MATERIAL ON THE BLANK, SHAPING ROLLS MOUNTED ADJACENT THE OPPOSITE SIDES OF THE MANDREL FOR PROGRESSIVELY FOLDING THE SIDE PORTIONS OF EACH BLANK ABOUT THE MANDREL SO AS TO OVERLAP THE SIDE MARGINS OF THE BLANK AND FORM THE SAME INTO A TUBE, MEANS ASSOCIATED WITH THE MANDREL FOR BRINGING THE OUTERMOST SIDE MARGIN OF THE BLANK INTO LAP SEAM FORMING ENGAGEMENT WITH THE INNERMOST MARGIN THEREOF BY ENGAGING SAID OUTERMOST MARGIN AT A PLURALITY OF LONGITUDINALLY SPACED POINTS AND APPLYING PRESSURE SIMULTANEOUSLY ALONG THE LENGTH OF THE SEAM, MEANS FOR STRIPPING THE TUBE FROM THE MANDREL AND MEANS FOR IMMEDIATELY PRESSING THE WALLS OF THE TUBE TO GIVE THE TUBE A TEMPORARY, GENERALLY ELLIPSOIDAL CROSS SECTION AND THEREAFTER RELEASING THE SAME TO PERMIT IT TO ASSUME A FINAL CYLINDRICAL SHAPE WITH A SUBSTANTIALLY UNIFORM DIAMETER.

Claim 2

AN APPARATUS FOR FORMING A TUBULAR CONTAINER BODY FROM A BLANK OF RELATIVELY THIN FLEXIBLE SHEET MATERIAL HAVING A SEAL FORMING MATERIAL ON A SIDE MARGINAL PORTION WHICH IS ADAPTED TO BE OVERLAPPED WITH THE OPPOSITE SIDE MARGINAL PORTION SO AS TO FORM A LAPPED SEAM, SAID APPARATUS COMPRISING AN ELONGATE CYLINDRICAL FORMING MANDREL DISPOSED IN A GENERALLY HORIZONTAL POSITION, A BLANK SUPPLY MAGAZINE ADJACENT AN ENTRANCE END OF THE MANDREL, MEANS FOR FEEDING SUCCESSIVE BLANKS FROM THE SUPPLY MAGAZINE, A BLANK ADVANCING CONVEYOR HAVING MEANS THEREON FOR ENGAGING THE TRAILING EDGE OF EACH SUCCESSIVE BLANK AND FOR ADVANCING THE SAME TO SAID MANDREL, MEANS ALONG THE BLANK FEED CONVEYOR FOR BENDING A SIDE MARGIN OF EACH SUCCESSIVE BLANK TO IMPART THERETO A SLIGHT CURVATURE, AN OVERHEAD CONVEYOR MOUNTED ON END SUPPORTS WHICH ARE DISPOSED AT OPPOSITE ENDS OF SAID FORMING MANDREL WITH THE BOTTOM RUN OF THE CONVEYOR TRAVELING IN A GENERALLY PARALLEL PATH IMMEDIATELY ABOVE THE TOP SURFACE OF THE MANDREL, SPACED BLOCKS ON SAID OVERHEAD CONVEYOR HAVING OUTWARDLY FACING CURVED SURFACES CONFORMING GENERALLY TO THE CURVATURE OF SAID MANDREL AND MEANS RESILIENTLY MOUNTED ON SAID BLOCKS FOR ENGAGING THE TRAILING EDGE OF EACH SUCCESSIVE BLANK AS IT IS ADVANCED TO THE LEADING END OF THE BLANK FEED CONVEYOR AND FOR ADVANCING SAID BLANK ALONG THE TOP SURFACE OF SAID MANDREL, THE CURVED FACES OF SAID BLOCKS SERVING TO PRELIMINARILY SHAPE EACH SUCCESSIVE BLANK AND START THE FOLDING THEREOF ABOUT THE TOP SURFACE OF THE MANDREL, HEATING MEANS ADJACENT THE MANDREL FOR ACTIVATING THE SEAL FORMING MATERIAL ON THE BLANK, SHAPING ROLLS MOUNTED ADJACENT THE OPPOSITE SIDES OF THE MANDREL FOR PROGRESSIVELY FOLDING THE SIDE PORTIONS OF EACH BLANK ABOUT THE MANDREL SO AS TO OVERLAP THE SIDE MARGINS OF THE BLANK AND FORM THE SAME INTO A TUBE, MEANS ASSOCIATED WITH THE MANDREL FOR BRINGING THE OUTERMOST SIDE MARGIN OF THE BLANK INTO LAP SEAM FORMING ENGAGEMENT WITH THE INNERMOST MARGIN THEREOF BY ENGAGING SAID OUTERMOST MARGIN AT A PLURALITY OF LONGITUDINALLY SPACED POINTS AND APPLYING PRESSURE SIMULTANEOUSLY ALONG THE LENGTH OF THE SEAM, MEANS FOR STRIPPING THE TUBE FROM THE MANDREL AND MEANS FOR IMMEDIATELY PRESSING THE WALLS OF THE TUBE TO GIVE THE TUBE A TEMPORARY, GENERALLY ELLIPSOIDAL CROSS SECTION AND THEREAFTER RELEASING THE SAME TO PERMIT IT TO ASSUME A FINAL CYLINDRICAL SHAPE WITH A SUBSTANTIALLY UNIFORM DIAMETER.