US 4,734,088 AGranted

Apparatus for making bags

AssigneeWindmoller & Holscher

InventorsFritz Achelpohl, Helmut Simon

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Abstract

Apparatus for severing bags from a two-ply web of thermoplastic material. The apparatus includes web guide rollers defining a nip, and a plurality of peripheral grooves in the guide rollers in which upper and lower air directing tubes are positioned to guide a web as it passes downstream of the feed rollers. A continuously transversely moving severing knife is provided downstream of the feed rollers and below the plane defined by the moving web. A pair of welding jaws are provided adjacent the cutting knife to grip the web in a plane below the web movement plane to weld the plies of the web together and to deflect the web into position for providing a transverse cut therein by means of the severing knife. A pivot lever is provided to pivot downstream ends of the lower air directing tubes in a downward direction to prevent interference between the downwardly deflected web and the downstream ends of the air directing tubes. A set of clamping jaws is provided on the opposite side of the severing knife from the welding jaws in order to securely hold the web during the cutting operation.

Claims15

Dependent claims

Apparatus for making bags from a two-ply web of thermoplastic material by transversely cutting the web at longitudinally spaced intervals, said apparatus comprising:

a frame;
feed means supported by said frame for intermittently moving web in a web movement direction and in a web movement plane;
welding means supported by said frame for welding together the two plies of thermoplastic material when the web is stopped, the welding being accomplished along a weld line extending transversely to the direction of web movement;
cutting means supported by said frame for severing a bag from the web along a cutting line spaced downstream from and substantially parallel to said weld line, said cutting means including a severing knife positioned below the web movement plane and supported and guided for movement in a transverse direction relative to the web movement direction;
said welding means being operable to deflect the stopped web downwardly toward the severing knife a distance sufficient to weld the plies of the web and to enable the severing knife to sever the web in a transverse direction relative to the web movement direction,
clamping means positioned on an opposite side of said severing knife from said welding means for clampingly engaging the web while welding thereof only takes place by said welding means,
carrying means for carrying said severing knife, and
convex beam means positioned below an upper run of said carrying means for carrying said severing knife in upward and downward directions relative to the web movement plane to cause cutting of the web to take place along a predetermined length of the severing knife.

5 more elements

Apparatus for making bags from a two-ply web of thermoplastic material by transversely cutting the web at longitudinally spaced intervals, said apparatus comprising:

a frame;
feed means supported by said frame for intermittently moving a web in a web movement direction and in a web movement plane;
welding means supported by said frame for welding together the two plies of thermoplastic material when the web is stopped, the welding being accomplished along a weld line extending transversely to the direction of web movement;
cutting means supported by said frame for severing a bag from the web along a cutting line spaced downstream from and substantially parallel to said weld line, said cutting means including a severing knife positioned below the web movement plane and supported and guided for movement in a transverse direction relative to the web movement plane;
said welding means being operable to deflect the stopped web downwardly toward the severing knife a distance sufficient to weld the plies of the web and to enable the severing knife to sever the web in a transverse direction relative to the web movement direction;
carrying means for carrying said severing knife;
and
convex beam means positioned below an upper run of said carrying means for carrying said severing knife in upward and downward directions relative to the web movement plane to cause movement of said severing knife toward and away from the plane of the web to thereby avoid having the same cutting portion of said severing knife from continuously cutting the web.

5 more elements

Dependencies are inferred from the claim text.