Undulating Plastic Film Supporting and Aligning Apparatus

Abstract

Apparatus for vertically supporting and maintaining a web of plastic film horizontally aligned in applications such as machines that form the plastic film into bags and fill them. Separate coplanar consecutively spaced plates are aligned with and extend through a web normal traversing plane. One of the plates has a peak edge extending out of the web normal traversing plane in a first direction, whereas another has a peak edge extending out of the web normal traversing plane in a second opposite direction. The peak edges define an undulating plastic film travel path between a web upstream location and a web downstream location. The web of film is tensioned between the upstream location and the downstream location and travels along the continuous undulating path. The film flexibly bends over the peak edges as a result of the tension and is thereby supported and maintained aligned.

What is claimed is: 
     
         1 . An apparatus for supporting and maintaining a web of film aligned along a web normal traversing plane comprising:
 a first plate having a first undulating shaped edge;   a second plate having a second undulating shaped edge;   wherein said first undulating shaped edge is proximate to and a mirror image of said second undulating shaped edge, thereby forming an undulating gap therebetween;   wherein an upstream opening at one terminal end of said undulating gap and a downstream opening at an opposite terminal end of said undulating gap communicate with said undulating gap and are aligned with one another along the web normal traversing plane;   wherein the web of film is received and traverses through said undulating gap from said upstream opening to said downstream opening; and,   wherein the web of film is tensioned between said upstream and downstream openings while traveling through said undulating gap, whereby the web of film is supported on said first and second plates and remains aligned with the web normal traversing plane.   
     
     
         2 . The apparatus of  claim 1  wherein said first and second undulating shaped edges include peaks or valleys extending outside of the web normal traversing plane. 
     
     
         3 . The apparatus of  claim 2  wherein said peaks or valleys are circular shaped. 
     
     
         4 . The apparatus of  claim 3  wherein four peaks or valleys are provided between said upstream and downstream openings. 
     
     
         5 . The apparatus of  claim 2  wherein said peaks or valleys are sinusoidal shaped. 
     
     
         6 . The apparatus of  claim 5  wherein four peaks or valleys are provided between said upstream and downstream openings. 
     
     
         7 . The apparatus of  claim 1  wherein said first and second plates are planar shaped. 
     
     
         8 . The apparatus of  claim 7  wherein said first and second plates are bent parallel to said web normal traversing plane and thereby form longitudinally extending stiffening ribs. 
     
     
         9 . The apparatus of  claim 1  wherein a dancer bar assembly is provided upstream from said undulating gap upstream opening whereby said web of film is tensioned. 
     
     
         10 . The apparatus of  claim 9  wherein said web of film is formed into bags and a bag opening and closing assembly is provided downstream from said downstream undulating gap opening whereat said bags are selectively opened and closed. 
     
     
         11 . The apparatus of  claim 1  wherein said undulating gap has a width sufficient to snugly and freely receive the web of film therethrough. 
     
     
         12 . The apparatus of  claim 1  wherein said first and second undulating shaped edges are coplanar. 
     
     
         13 . The apparatus of  claim 1  wherein said first and second undulating shaped edges are in planes parallel to one another. 
     
     
         14 . The apparatus of  claim 1  wherein at least one of said first and second undulating shaped edges includes a peak extending outside of the web normal traversing plane and the web of film flexibly bends thereover as a result of said tension. 
     
     
         15 . The apparatus of  claim 1  wherein said first undulating shaped edge includes a peak extending outside of the web normal traversing plane and said second undulating shaped edge includes a valley extending outside of the web normal traversing plane, and the web of film flexibly bends over said peak as a result of said tension. 
     
     
         16 . The apparatus of  claim 1  wherein said first undulating shaped edge includes a plurality of peaks extending outside of the web normal traversing plane and said second undulating shaped edge includes a plurality of peaks extending outside of the web normal traversing plane, and the web of film flexibly bends over said peaks as a result of said tension. 
     
     
         17 . An apparatus for supporting a web of film traveling from an upstream location along a web normal traversing plane to a downstream location, said apparatus comprising:
 a plurality of separate consecutively spaced plates aligned with and extending through the web normal traversing plane;   wherein said plates are coplanar;   at least one of said plates includes a peak edge extending out of the web normal traversing plane in a first direction;   at least one of said plates includes a peak edge extending out of the web normal traversing plane in a second direction opposite said first direction;   wherein said peak edges define an undulating plastic film travel path extending between the upstream location and the downstream location;   wherein said web of film extends along said undulating path over said plates peak edges; and,   wherein the web of film is tensioned between the upstream location and the downstream location while traversing along said undulating path, whereby the web of film is supported by said plates.   
     
     
         18 . The apparatus of  claim 17  wherein the web of film flexibly bends over said peak edges as a result of said tension. 
     
     
         19 . The apparatus of  claim 18  wherein a dancer bar assembly is provided along and tensions said web of film. 
     
     
         20 . The apparatus of  claim 17  wherein a first plurality of said plates include a peak edge extending out of the web normal traversing plane in a first direction and a second plurality of said plates include a peak edge extending out of the web normal traversing plane in a second direction opposite said first direction, and wherein said first plurality of plates are located between the second plurality of plates. 
     
     
         21 . The apparatus of  claim 20  wherein the web of film flexibly bends over said peak edges as a result of said tension. 
     
     
         22 . The apparatus of  claim 21  wherein a dancer bar assembly is provided along and tensions said web of film. 
     
     
         23 . The apparatus of  claim 17  wherein a dancer bar assembly is provided upstream from said plurality of plates whereby said web of film is tensioned, and wherein said web of film is formed into bags and a bag opening and closing assembly is provided downstream from said plurality of plates whereat said bags are selectively opened and closed. 
     
     
         24 . The apparatus of  claim 17  wherein a dancer bar assembly is provided along and tensions said web of film. 
     
     
         25 . An apparatus for supporting a web of film traversing along a plane from a web upstream location to a web downstream location, said apparatus comprising:
 a first element having a peak edge extending outside of said traversing plane;   a second element having a peak edge extending outside of said traversing plane;   wherein said first element peak edge and said second element peak edge together define an undulating travel path extending between the upstream location and the downstream location;   wherein said web of film extends along said undulating travel path over said peak edges; and,   wherein the web of film is tensioned between the upstream location and the downstream location while traversing along said undulating travel path, whereby the web of film is supported by said elements.   
     
     
         26 . The apparatus of  claim 25  wherein said first element peak edge and said second element peak edge are coplanar. 
     
     
         27 . The apparatus of  claim 25  wherein said first element peak edge and said second element peak edge are consecutively spaced. 
     
     
         28 . The apparatus of  claim 25  wherein said first element peak edge and said second element peak edge are in planes parallel to one another. 
     
     
         29 . The apparatus of  claim 25  wherein said first and said second elements are on opposite sides of said traversing plane. 
     
     
         30 . The apparatus of  claim 25  wherein the web of film flexibly bends over said peak edges as a result of said tension.