Vertically Positioned Horizontally Traversing Plastic Film Bags Opening, Filling and Closing Apparatus Including Vertically Moving Supporting Conveyor

Abstract

In an automated machine that forms a vertically positioned and horizontally traversing web of plastic film into bags, the apparatus opens, fills and closes the bags and provides slack in the bag walls to close the bag. The bag upper longitudinal edge portions are separated at a bag opening and closing assembly for thereby opening and filing a bag with material. While the bag is being filled, the bag is supported on a conveyor. The conveyor is raised vertically toward the opening and closing assembly while the bag is being closed for thereby providing slack in the bag walls. The conveyor horizontally conveys the filled bag under while a gripping and pulling assembly pulls the bag longitudinal portions into a heat sealing assembly whereat the bag walls are fused together and sealed closed. The bag is thereafter conveyed away therefrom and the conveyor is again placed in its lower position.

What is claimed is: 
     
         1 . An apparatus for opening, filling and closing vertically positioned plastic film bags traversing horizontally from an upstream location to a downstream location wherein said bags include a pair of parallel proximate longitudinal edge portions defining a bag opening therebetween leading to a bag cavity vertically therebelow, said apparatus comprising:
 a bag opening and closing assembly whereat said pair of longitudinal edge portions are separated from one another thereby opening a bag leading into its bag cavity;   a bag supporting surface positioned vertically below said bag opening and closing assembly and being selectively vertically moveable between a lower position and an upper position;   wherein, while said bag is open, material is placed in said bag though said opening and said bag is vertically supported on said supporting surface in its lower position;   wherein said bag is closed by moving said separated longitudinal edge portions towards one another; and,   wherein, while said bag is being closed, said supporting surface is moved vertically upwardly from its lower position to its upper position thereby providing slack in said bag walls.   
     
     
         2 . The apparatus of  claim 1  wherein said supporting surface comprises a conveyor and wherein, after said bag is closed, said conveyor conveys said filled bag away from said bag opening and closing assembly. 
     
     
         3 . The apparatus of  claim 1  wherein, while said pair of longitudinal edge portions are being separated from one another and said bag is being opened, additional longitudinal edge portions are pulled into the bag opening and closing assembly from at least one of said upstream and downstream locations and, while said pair of longitudinal edge portions are being moved towards one another and the bag is being closed, said additional longitudinal edge portions are pulled out of said bag opening and closing assembly towards at least one of said upstream and downstream locations. 
     
     
         4 . The apparatus of  claim 3  wherein a dancer bar assembly is provided at said upstream location and provides tension in said longitudinal edge portions and pulls said additional edge portions out of said bag opening and closing assembly while said bag is being closed. 
     
     
         5 . The apparatus of  claim 3  wherein a gripping and pulling assembly is provided at said downstream location and pulls said additional edge portions out of said bag opening and closing assembly while said bag is being closed. 
     
     
         6 . The apparatus of  claim 5  wherein said supporting surface comprises a conveyor and wherein said gripping and pulling assembly further pulls said longitudinal edge portions out of said bag opening and closing assembly to a plastic film heat sealing assembly while said conveyor conveys said filled bag away from said bag opening and closing assembly to under said heat sealing assembly. 
     
     
         7 . The apparatus of  claim 6  wherein, at said heat sealing assembly, said bag walls are heat fused to one another and the bag is sealed closed and, thereafter, said bag is conveyed away from said heat sealing assembly and said conveyor is placed in its lower position. 
     
     
         8 . The apparatus of  claim 3  wherein said additional longitudinal portions at said upstream location extend through a pair of upstream clamping members and said additional longitudinal portions at said downstream location extend through a pair of downstream clamping members and wherein, while said bag is in its closed position, said upstream and downstream clamping members allow said additional longitudinal portions to traverse therethrough and, while said bag is in its open position, said upstream and downstream clamping members clampingly grip and prevent said additional longitudinal portions to traverse therethrough. 
     
     
         9 . The apparatus of  claim 8  wherein said clamping members are rubber rollers and wherein, while said bags are being opened and closed, said rollers guide said additional longitudinal edges as they traverse therethrough. 
     
     
         10 . The apparatus of  claim 1  further comprising a pair of horizontally extending guide bars positioned vertically between said bag opening and closing assembly and said bag supporting surface and positioned on opposite sides of said bag whereat said guide bars horizontally support said bags. 
     
     
         11 . The apparatus of  claim 10  wherein said bag supporting surface is joined with said guide bars and said supporting surface and guide bars are vertically moveable between said upper and lower positions in unison. 
     
     
         12 . The apparatus of  claim 11  further comprising a pneumatic cylinder coupled to one of said supporting surface and guide bars for thereby selectively vertically moving said supporting surface and guide bars. 
     
     
         13 . The apparatus of  claim 11  wherein said supporting surface comprises a conveyor and wherein, after said bag is closed, said conveyor conveys said filled bag away from said bag opening and closing assembly. 
     
     
         14 . The apparatus of  claim 1  wherein said bags traverse along a normal traversing plane and said bag opening and closing assembly comprises:
 a first gate on one side of said normal traversing plane selectively moveable between a closed position adjacent said normal traversing plane and an open position at a distance away from said normal traversing plane; 
 a second gate on the other side of said normal traversing plane opposing said first gate and selectively moveable between a closed position adjacent said normal traversing plane and an open position at a distance away from said normal traversing plane; 
 wherein each said first and second gates include a longitudinal channel receiving one of said bag longitudinal edge portions therethough; 
 wherein said longitudinal channels allow said bag edge portions to traverse therethrough when said gates are in their closed position and clampingly grip said bag edge portions when said gates are away from their closed position; and, 
 wherein, when said gates are in their open positions, said bag longitudinal portions are gripped and separated from one another for thereby opening and filling the bag and, when said gates are in their closed positions, said bag longitudinal portions are released and allowed to longitudinally traverse through their respective longitudinal channel. 
 
     
     
         15 . The apparatus of  claim 14  wherein each said longitudinal channel is formed between a leading gate plate and a selectively moveable clamp bar, said clamp bar being moveable away from said leading gate plate when said gate is in its closed position thereby opening said longitudinal channel and allowing said bag edge portion to traverse therethrough, and being moveable against said leading gate plate when said gate is away from its closed position thereby closing said longitudinal channel and clampingly griping said bag edge portion therebetween. 
     
     
         16 . The apparatus of  claim 15  wherein one or more springs move said clamp bar against said leading gate plate when said gate is away from its closed position. 
     
     
         17 . The apparatus of  claim 14  wherein, while said gates are being moved from their closed positions to their open positions, additional longitudinal edge portions are pulled into said bag opening and closing assembly from at least one of said upstream and downstream locations and, while said gates are being moved from their open positions to their closed positions, said additional longitudinal edge portions are pulled out of said bag opening and closing assembly towards at least one of said upstream and downstream locations. 
     
     
         18 . The apparatus of  claim 17  wherein a dancer bar assembly is provided at said upstream location and provides tension is said longitudinal edge portions and pulls said additional edge portions out of said apparatus while said gates are being closed. 
     
     
         19 . The apparatus of  claim 17  wherein a gripping and pulling assembly is provided at said downstream location and pulls said additional edge portions out of said apparatus while said gates are being closed. 
     
     
         20 . The apparatus of  claim 17  wherein said additional longitudinal portions at said upstream location extend through a pair of upstream clamping members and said additional longitudinal portions at said downstream location extend through a pair of downstream clamping members and wherein, while said gates are in their closed positions, said upstream and downstream clamping members allow said additional longitudinal portions to traverse therethrough and, while said gates are in their open positions, said upstream and downstream clamping members clampingly grip and prevent said additional longitudinal portions to traverse therethrough.