Apparatus for Pulling Vertically Positioned Horizontally Traversing Plastic Film Bag Walls and Heat Fusing the Walls and Closing the Bag
In an automated machine that forms a vertically positioned and horizontally traversing web of plastic film into bags and fills the bags with material, after the bags are filled, a pair of gripping fingers clampingly grip and pull the bag upper longitudinal edge portions into a sealing gap between a pair of heat seal bars whereat the bag walls are heat fused together and the bag is sealed closed. A pair of clamp bars below the heat seal bars clampingly engage the bag walls after they are pulled into the gap and prior to heat sealing. The filled bags are linked along their longitudinal edge portions with perforations therebetween. The bags are severed from one another at a perforation when the gripping fingers pull the bag walls into the gap. The gripping fingers are carried on and are moved longitudinally with a pair of belts located vertically above the gap.
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1. Field of the Invention
The present invention relates to the field of automated machines that form a vertically positioned and horizontally traversing web of plastic film into bags and fill the bags with material. More particularly, the present invention relates to an apparatus that grips and pulls the bag upper longitudinal edge portions into a gap between a pair of heat seal bars whereat the bag walls are heat fused together and the bag is sealed closed.
2. Background
Automated machines that form a web of plastic film into bags and fill them with material are today commonly known and used. Some of these machines also utilize a plastic film web that is situated vertically and fed into the machine horizontally. Examples of such machines are shown in: U.S. Pat. No. 2,853,842; U.S. Pat. No. 2,885,846; U.S. Pat. No. 3,241,290; U.S. Pat. No. 3,359,703; U.S. Pat. No. 3,597,895; U.S. Pat. No. 3,699,746 U.S. Pat. No. 3,753,332; and, U.S. Pat. No. 4,617,785.
Although the prior known machines are satisfactory, a need exists for a machine that forms a vertically positioned horizontally fed web of plastic film into bags and fills the bags with material and which has a relatively high output, takes a relatively small footprint, and is more efficient and reliable.
SUMMARY OF THE INVENTIONThe present invention overcomes disadvantageous of prior automated plastic film bag forming and filling machines and provides additional advantageous and benefits as described hereinbelow.
In one form thereof the present invention is directed to an apparatus for heat seal closing vertically positioned plastic film bags which include a pair of plastic film walls having upper terminal longitudinal edge portions and wherein the longitudinal edge portions are proximate and parallel to one another. The apparatus includes a pair of elongate parallel heat seal bars defining a longitudinally extending heat sealing gap therebetween and selectively moveable into the heat sealing gap adjacent one another. A pair of gripping fingers are provided which define a gripping gap therebetween and are selectively moveable into the gripping gap adjacent one another. The gripping fingers are selectively moveable longitudinally along the longitudinally extending heat sealing gap. In operation, the bag terminal edge portions are placed in the gripping gap, the gripping fingers are moved adjacent one another and thereby clampingly grip the bag terminal edge portions, the gripping fingers are moved longitudinally along the heat sealing gap thereby pulling the bag walls within the heat sealing gap, and the heat seal bars are moved into the heat sealing gap engaging the bag walls therebetween whereby the bag walls are heat fused to one another and the bag is sealed closed.
Preferably, a pair of elongate parallel clamp bars are provided vertically below the heat seal bars. Each clamp bar is positioned on opposite sides of the heat sealing gap and are selectively moveable into the heat sealing gap adjacent one another. The clamp bars are thereby moved adjacent one another and clampingly engage the bag walls after the bags walls are pulled into the heat sealing gap and prior to the heat seal bars engaging the bag walls.
Also preferably, the heat seal bars and gripping fingers are located downstream from a bag opening assembly whereat the bags are opened and filled with material. The bags are preferably linked to one another at their upper terminal longitudinal edge portions and a weakened attachment line is provided in the longitudinal edge portions between each bag and wherein, when the bag is pulled by the gripping fingers, the bag being pulled into the heat sealing gap is severed from an upstream bag at the weakened attachment line. The weakened attachment line can be a perforation.
Further preferably, each gripping finger includes a raised contact face, a raised gripping rib and a relief gap therebetween. When the pair or gripping fingers are moved adjacent one another, the respective contact faces oppose each other, the raised gripping ribs oppose each other and the relief gaps oppose each other, and the bag terminal edge portions are clampingly gripped between the raised gripping ribs.
The gripping fingers are preferably located vertically above the heat seal bars. At least one drive belt is selectively moveable along the longitudinally extending heat sealing gap, and the gripping fingers are carried on the belt and are thereby selectively moveable longitudinally along the longitudinally extending heat sealing gap. A pneumatic cylinder is coupled to each of the gripping fingers and are actuated for thereby selectively moving the gripping fingers into the gripping gap adjacent one another.
The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of the embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout several views. Although the exemplification set out herein illustrates embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSReferring initially to
Referring now also to
The process of forming and filling of the plastic film bags is diagrammatically depicted and generally shown in
The web of plastic film 36 comprises an elongate web of plastic film which has been folded along a longitudinal central fold line 44 and which thereby defines a pair of plastic film walls 46L, 46R extending between the film fold line 44 and respective longitudinal edges 48L, 48R. The plastic film web 36 is, therefore, U-shaped as viewed in cross section (
After the plastic film web 36 is unwound/removed from the roll 38, it travels into the machine 10 through an opening 50 in the end tube member 30R, over the dancer bar assembly 18, and then through the perforation and sides seal assembly 20. At the perforation and sides seal assembly 20, the web walls 46L, 46R are severed along a vertical separation 52 extending from the longitudinal central fold line 44a distance of about 1 to 2 inches below the longitudinal film edges 48L, 48R. This distance is diagrammatically depicted with a short-long dash line 54. The edges formed along the plastic film walls 46L, 46R at the vertical separation 52 are simultaneously heat sealed/fused to one another thereby creating bag fore side seal edges 56F and bag aft side seal edges 56A. As the web 36 travels through the perforation and sides seal assembly 20, the vertical separations 54 and resulting fore and aft side seal edges 56F, 56A are formed at a desired distance from one another for thereby forming bags 58 defining a cavity 60 between the severed walls 46L, 46R. The bags 58 hence have a height equal to the length of the vertical separation 52 and a width equal to the distance between their fore side seal edge 56F and their aft side seal edge 56A.
The longitudinal edge portions 62L, 62R of the respective plastic film walls 46L, 46R which are located above the short-long dash line 54 remain separated from one another and, hence, define a bag opening 64 therebetween into the bag cavity 60. Also, at the perforation and sides seal assembly 20, the longitudinal edge portions 62L, 62R are both perforated along a perforation line 66 which is vertically aligned with the vertical separation 52. The perforation lines 66 extend from above the vertical separation 52, essentially, from the short-long dash line 54 to the plastic film longitudinal edges 48L, 48R. The perforation lines 66 essentially form vertical weakened attachment lines which are used downstream for separating the bags 58 from the web 36 after the bags have been filled and prior to heat sealing them closed.
After the perforation and sides seal assembly 20, the web 36 formed bags 58 travel through the undulating edge film guiding and supporting assembly 22 to the opening and closing assembly 24. At the bag opening and closing assembly 24, the longitudinal edge portions 62L, 62R above a bag 58 and between a pair of perforation lines 66 are separated from one another for thereby exposing the bag opening 64 and, as shown in
After the bag at the opening and closing assembly 24 has been filled and closed, the vertically moving and horizontally conveying assembly 28 conveys it under the bag pulling and sealing assembly 26 while, simultaneously, the pulling and sealing assembly 26 pulls the longitudinal edge portions 62L, 62R therein. As the longitudinal edge portions 62L, 62R are pulled into the pulling and sealing assembly 26, they are separated from the upstream bag 58 web 36 at the perforation line 66 therebetween. At the pulling and sealing assembly 26, the bag film walls 46L, 46R are heat sealed/fused to one another along a closure line 324 (
As further described herein below, the vertically moving and horizontally conveying assembly 28 cooperates with the opening and closing assembly 24 and the pulling and sealing assembly 26 and functions to vertically support and move and horizontally convey the bags while they are being filled, closed, heat sealed closed and, finally, removed from the machine 10. The undulating edge film guiding and supporting assembly 22 receives the plastic film longitudinal portions 62L, 62R therethrough and functions to support/carry the bags 58 and maintain the plastic film longitudinal portions 62L, 62R horizontally aligned as the web travels into the opening and closing assembly 24. The dancer bar assembly 18 functions to maintain tension in the plastic film longitudinal portions 62L, 62R extending between the roll 38 and the opening and closing assembly 24 as the longitudinal portions 62L, 62R travel through the perforation and sides seal assembly 20 and the undulating edge film guiding and supporting assembly 22.
The plastic film roll supporting and feeding apparatus 16 includes a carriage 70 slidingly captured between vertical side beams 72L, 72R which are attached to the end member 30R, and is thereby vertically movable. A threaded rod 74 is, at its lower end thereof, threadingly coupled to the carriage 70. The upper end of the threaded rod 74 extends through the upper horizontal tube of the end member 30R and a crank handle 76 is coupled thereto. Accordingly, the carriage 70 is selectively vertically adjustable by turning the crank handle 76 and causing the threaded rod 74 to be received or extended from the carriage 70 relative to the end frame 30R.
A carriage arm 78 is attached to and extends out from the carriage 70. A roll supporting disk 80 and a shaft drive unit 82 are mounted on and are supported by the arm 78. The drive unit 82 is coupled to and rotatably drives the supporting disk 80 about the vertical axis 40, in a clockwise direction as viewed from the top, as indicated by arrow 84 (
An upper roll stabilizing arm 86 is pivotally coupled to the upper horizontal tube of the end member 30R so as to pivot about a horizontal axis as indicated by arrow 88 (
As should now be appreciated, successive plastic film rolls 38 can be placed on the supporting disk 80 by pivotally lifting the stabilizing arm 86 and boss 90 as indicated by arrow 88. Also, by turning the crank handle 76 the vertical height of the plastic film roll 38 sitting on the supporting disk 80 can be adjusted for horizontally aligning the plastic film web 36 and its longitudinal edge portions 62L, 62R with the machine assemblies 18, 20, 22, 24, 26 and 28.
As mentioned herein above, the dancer bar assembly 18 functions to maintain tension in the plastic film longitudinal portions 62L, 62R of the web 36 extending between the roll 38 and the opening and closing assembly 24 as the longitudinal portions 62L, 62R travel through the perforation and sides seal assembly 20 and the undulating edge film guiding and supporting assembly 22. The dancer bar assembly, as shown in
An L-shaped dancer bracket 110 is secured to the shaft 92 and rotates therewith about the vertical axis 104. L-shaped dancer bracket 110 includes a roller arm 106 extending perpendicular from the shaft 92 and a spring arm 108 extending perpendicular from the shaft 92 and, also, generally perpendicular from the roller arm 106.
An upstream concave shaped film guide roller 112 is rotatably secured to the terminal end of the roller arm 106 and freely rotates about a vertical axis 114 relative to the roller arm 106. Hence, the roller 112 also rotates/is movable along with the roller arm 106 about the vertical axis 104. Roller 112 can be rotatably secured to the arm 106 as, for example, shown with a shoulder bolt 116 extending therethough and being threadingly secured to the arm 106. Roller 112 is preferably made of rubber, nylon or other suitable material adapted to engage the plastic film web 36. Roller 112, as best seen in the elevation view of
A downstream convex shaped film guide roller 122 is rotatably secured to the lower terminal end of the dancer bar shaft 92, coaxially with the shaft 92, and freely rotates about the vertical axis 104 relative to the shaft 92. Hence, although roller 122 rotates about its axis 104, it is fixed/stationary relative to the upstream roller 112 which rotates/moves with the dancer bracket arm 106.
Roller 122 can similarly be rotatably secured to the shaft 92 as, for example, shown with a shoulder bolt 124 extending therethough and being threadingly secured to the shaft 92. Roller 122 is also preferably made of rubber, nylon or other suitable material adapted to engage the plastic film web 36. Roller 122, as best seen in the elevation view of
As best seen in
A rotational sensor 136 is mounted with a bracket 138 to the upper frame bracket 94 adjacent the upper terminal end of the dancer bar shaft 92. Sensor 136 is coupled with the upper terminal end of the shaft 92 with a magnetic or mechanical coupling 140 and, hence, provides an output signal representative of the rotational position of the shaft 92 about the vertical axis 104. As mentioned herein above, the output signal from the dancer bar sensor 136 is used to selectively energize the supporting and feeding assembly drive unit 82 and to thereby unwind the plastic film roll 38 and advance/deliver additional plastic film web 36 into the machine 10.
In operation, as best seen in
Additionally, it has also been found that, because upstream guide roller 112 is concave shaped and downstream guide roller 122 is convex shaped and by maintaining tension on the web longitudinal edge portions 62L, 62R, the web edge portions 62L, 62R remain horizontally aligned over the guide rollers 112, 122 with the web walls 46L. 46R extending/hanging therebelow. It has also been found that such horizontal alignment is best maintained with the upstream movable roller 122 being concave shaped and the downstream stationary roller 122 being convex shaped.
After the dancer bar assembly 18, the web 36 travels through the perforation and sides seal assembly 20. The perforation and sides seal assembly 20, as shown in
A vertically positioned heat seal backer plate 154 is mounted on the assembly housing 144 adjacent to and spaced from the heat seal bar 146. Accordingly, a plastic film web receiving vertical gap 156 is provided between the heat seal bar 146 and the backer plate 154. The plastic film web 36 is received through the vertical gap 156 and freely traverses therethrough when the heat seal bar 146 is retracted as shown in
To assist in the separation of the side seal edge 56F from the side seal edge 56A and assure that a consistent and complete vertical separation 52 is provided between the bags 58, one or more air nozzles 158 are provided on the assembly housing 144 adjacent to and downstream from the heat seal bar 146 and backer plate 154. See
A perforation knife subassembly 160 is provided vertically above and aligned with the heat seal bar 146 and backer plate 154. Subassembly 160 includes a pneumatic cylinder 162, a perforation knife 164 and a web and knife guide block 166. The pneumatic cylinder 162 includes a piston rod attachment block 168 which is rectangular shaped and is slidingly received through a horizontal slot 170 extending through the guide plate 172 (not shown in
A pair of mounting wings 176 are secured to and extend perpendicularly in opposite directions from the perforation knife 164. The mounting wings 176 are secured to the pneumatic cylinder attachment block 168 with fasteners (not shown). Perforation knife 164 is thereby carried on and movable with the attachment block 168 while being restrained from rotating about the longitudinal/travel axis 174. The perforation knife 164 includes a plurality of horizontally projecting vertically aligned needles 178 having a sharp tip 180 and a stem 182. Spaces 184 are thereby formed between the needle stems 182. The perforation knife 164 and, hence, the needles are vertically oriented, aligned in the same plane with the heat seal bar 146 and perpendicular to the web 36 travelling through the vertical gap 156.
The guide block 166 includes a vertical web slot 186 extending horizontally therethrough in a plane parallel with the web 36. The web slot 186 is defined between an inner surface 1861 and an outer surface 1860. The inner surface 1861 is coplanar with the heat seal backer plate surface 154S. An opening 188 at the lower end of the block 166 leads to the web slot 186. Accordingly, as diagrammatically shown in
The guide block 166 also includes a vertical knife slot 190 extending horizontally therethrough in a plane perpendicular with the web 36. Vertical knife slot 190 is, therefore, also perpendicular to and crosses the vertical web slot 186. Knife slot 190 is adapted to slidingly receive and guide the perforation knife 164 perpendicularly across the web slot 186, as shown in
In operation, the perforation lines 66 are preferably formed simultaneously with the vertical separations 52 (
As the web 36 travels through the perforation and sides seal assembly 20 and while it is between the dancer bar assembly 18 and the bag opening and closing assembly 24, the undulating edge film guiding and supporting assembly 22 functions to maintain the web 36 horizontally aligned and to support/carry the bags 58 to the bag opening and closing assembly 24. Undulating edge film guiding and supporting assembly 22 includes a pair of horizontally aligned/coplanar plates 192L, 192R which are secured to the machine frame plate 100 with vertically extending studs 194L, 194R and fastener bolts 196. Plates 192L, 192R are thereby spaced from and hang below the machine frame plate 100. Plates 192L, 192R are made of steel or other suitably hard material and are relatively thin, i.e., 1/16 inch to ¼ inch, in relation to the web walls 46L, 46R film thickness which is typically less than 100 mil.
The outside longitudinal edges of plates 192L, 192R are bent perpendicular thereto and form respective longitudinally extending stiffening ribs 198L, 198R. The inside longitudinal edges 200L, 200R of plates 192L, 192R have an undulating shape as viewed from the top. As used herein, “undulating” means a smooth wavelike shape relative to the longitudinal normal traversing plane along which the plastic film web 36 travels from an upstream location to a downstream location and which is depicted in
Edges 200L, 200R are provided with at least one peak and/or valley relative to the web longitudinal normal traversing plane 202, although a plurality of peaks and valleys are preferred. In the most preferred embodiment of machine 10, edges 200L, 200R are provided with four peaks and/or valleys relative to the web longitudinal normal traversing plane 202, as shown in
Referring now more particularly to
As should now further be appreciated, the folds/bends causing the tensioned web 36 to align with and vertically “grip” the undulating plates edges 200L, 200R occur at the peaks of the undulating edges 200L, 200R which are displaced relative to/which extend out of the web longitudinal normal traversing plane 202. Accordingly, the valley portions of the plates 192L, 192R can be eliminated. That is, the valley portions 192L-V and 192R-V depicted by cross-hatching in
In both embodiments of
Through experimentation it has further been found that the plates 192L, 192R need not be coplanar and, in fact, function equally as well, if not better, when they are located in parallel planes to one another and are vertically offset as depicted in
There are times when tension in the web 36 cannot be provided and/or is not desired such as when machine 10 is being serviced and when the plastic film web 36 is initially being threaded therethrough. In this regard, as shown in
As mentioned hereinabove, after traversing through the undulating edge film guiding and supporting assembly 22, the web 36, which was previously formed into bags 58 linked by the longitudinal edge portions 62L, 62R, travels to the bag opening and closing assembly 24 whereat the longitudinal edge portions 62L, 62R are separated for opening and filling the bags 58 and are then brought back together/adjacent one another and closing the bags 58. The bag opening and closing assembly 24, as more particularly shown in
An upstream crossbeam 224U and a downstream crossbeam 224D are fixed to the underside of the frame plate 100 and extend vertically downwardly therefrom and perpendicular to the web normal traversing plane 202. Crossbeams 224U, 224D each include a notch 226 which open downwardly and through which the web longitudinal edge portions 62L, 62R are received. Longitudinal crossbeams 227L, 227R are similarly fixed to the underside of the frame plate 100 and extend vertically downwardly therefrom. Longitudinal crossbeams 227L, 227R, however, are parallel to the web longitudinal edge portions 62L, 62R and extend between and perpendicular to the upstream and downstream crossbeams 224U, 224D.
Sliding gates 220L, 220R include respective gate plates 228L, 228R extending between the upstream and downstream crossbeams 224U, 224D. Upper and lower gate bearings 230U, 230L are rotatably secured to the upstream and downstream crossbeams 224U, 224D. Gate plates 228L, 228R are positioned between the upper and lower gate bearings 230U, 230L and are thereby slidingly supported on the upstream and downstream crossbeams 224U, 224D. Gate plates 228L, 228R are, thus, movable perpendicularly towards and away from the web normal traversing plane 202. Leading gate closure and film guide plates 232L, 232R are secured to the gate plates 228L, 228R and extend perpendicularly downward therefrom along the gate plates 228L, 228R inner edge. As best seen in
The sliding gates 220L, 220R each include a respective clamp bar 238L, 238R slidingly mounted on a respective gate plate 228L, 228R and, together with a respective gate closure and film guide plate 232L, 232R, forming a clamp/gripper having a respective longitudinal channel 240L, 240R wherethrough the respective web longitudinal edge portions 62L, 62R are received (
Importantly, the overall length of the rods 242 and width of their respective clamp bars 238L, 238R (from the rubber longitudinal strip 250 at the clamp bars gripping/clamping face to the rod stops 246) is shorter than the distance between the gate closure and film guide plates 232L, 232R and their respective longitudinal crossbeams 227L, 227R when the gates 220L, 220R are in their closed positions as seen in
The bag opening and closing assembly 24 further includes a pair of upstream opposing rubber rollers 252L, 252R carried on the upstream crossbar 224U and adapted to receive and guide the web longitudinal edge portions 62L, 62R therebetween. Pneumatic cylinders 254, also carried on the upstream crossbar 224U, are coupled to the rollers 252L, 152R and are adapted to selectively: extend and firmly compress the rollers 252L, 252R against each other at a high pressure to prevent rotation thereof and thereby pinch/clamp the web longitudinal edge portions 62L, 62R therebetween and prevent longitudinal movement thereof (rollers “clamped position”); extend and compress the rollers 252L, 252R against each other at a low pressure and allowing rotation thereof to thereby lightly grip and allow movement of the web and to thereby guide the web longitudinal edge portions 62L, 62R traversing therebetween (rollers “guiding position”); and, relax and/or retract the rollers 252L, 252R to thereby freely allow movement of the web longitudinal edge portions 62L, 62R therethough (rollers “released position”).
Similarly, a pair of downstream opposing rubber rollers 256L, 256R are carried on the downstream crossbar 224D and are adapted to receive and guide the web longitudinal edge portions 62L, 62R therebetween. Pneumatic cylinders 254, also carried on the downstream crossbar 224D, are coupled to the rollers 256L, 156R and are adapted to selectively: extend and firmly compress the rollers 256L, 256R against each other at a high pressure to prevent rotation thereof and thereby pinch/clamp the web longitudinal edge portions 62L, 62R therebetween and prevent longitudinal movement thereof (rollers “clamped position”); extend and compress the rollers 256L, 256R against each other at a low pressure and allowing rotation thereof to thereby lightly grip and allow movement of the web and to thereby guide the web longitudinal edge portions 62L. 62R traversing therebetween (rollers “guiding position”); and, relax and/or retract the rollers 256L, 256R away from each other to thereby freely allow movement of the web longitudinal edge portions 62L, 62R therethough (rollers “released position”).
Referring now more particularly to
When the gates have reached their fully open position as shown in
The bag pulling and sealing assembly 26 includes a heat sealing subassembly 258 for heat sealing/fusing the bag film walls 46L, 46R to one another between the fore and aft side seal edges 56A, 56F and a gripping and pulling subassembly 260 for pulling the web longitudinal edge portions 62L, 62R into the heat sealing subassembly 258. After the bag 58 has been filled, closed and the web longitudinal edge portions 62L, 62R released, the vertically moving and horizontally conveying assembly 28 conveys it to the bag pulling and sealing assembly 26 while, simultaneously, the pulling and gripping subassembly 260 grips and pulls the web longitudinal edge portions 62L, 62R into the heat sealing subassembly 258.
The bag heat sealing subassembly 258 includes a pair of elongate horizontally disposed heat seal bars 262L, 262R extending parallel with the web 36 and adapted to travel in a horizontal plane, opening and closing in a direction perpendicular to the web 36 toward and away from the normal horizontally straight web traversing plane (depicted by the long dash line 202 in
The heat seal bars 262L, 262R are carried on a respective carrying block 266L, 266R. A pair of horizontally positioned pneumatic cylinders 264L, 264R are mounted on the heat seal assembly housing 265 (
A pair of horizontally positioned slide guide bars 268L. 268R are slidingly received through respective horizontally positioned cylindrical support members 270L, 270R. The cylindrical support members 270L, 270R include flanges 267 and are, thereby, mounted on the heat seal assembly housing 265. The pair of slide guide bars 268L are coupled to the carrying block 266L longitudinally upstream and downstream from the pneumatic cylinder 264L. Similarly the pair of slide guide bars 268R are coupled to the carrying block 266R longitudinally upstream and downstream from the pneumatic cylinder 264R. Accordingly, the carrying blocks 266L, 266R and the heat seal bars 262L, 262R thereon are maintained in their horizontal orientation while also being extendable and retractable by their respective pneumatic cylinder 264L, 264R as shown in
Horizontally disposed clamp bars 272L, 272R are mounted on respective carrying blocks 266L, 266R vertically below and parallel with respective heat seal bars 262L, 262R and the web 36 normal traversing plane 202. As best seen in
As should now be appreciated and shown in
After a bag 58 is conveyed under the heat sealing subassembly 258 and the plastic film walls 46L, 46R thereof are received in the gap 284 as shown in
The gripping and pulling subassembly 260 includes a drive belt unit 286 mounted on the end tube member 30L and rotatably driving the drive toothed belt pulleys 288L, 288R. Drive pulleys 288L, 288R are coupled with respective driven toothed belt pulleys 290L, 290R with respective toothed belts 292L, 292R. The driven pulleys 290L, 290R are rotatably supported on the machine upper beams 34L, 34R and are located adjacent the bag opening and closing assembly 24. As best seen in
A carriage 294 extends horizontally perpendicular to the web 36 longitudinal normal traversing plane 202 and between the toothed belts 292L and 292R. Carriage 294 is clamped onto and is secured to the toothed belts 292L, 292R and is thereby adapted to travel longitudinally along the web 36 normal traversing plane 202 between the drive pulleys 288L, 288R and the driven pulleys 290L, 290R. Preferably, carriage 294 is secured to the lower longitudinally extending bands of the toothed belts 292L, 292R thereby placing it vertically closer to the heat sealing subassembly 258.
A pair of gripping fingers 296L, 296R are coupled to respective pneumatic cylinders 298L, 298R which are, in turn, mounted on and carried by the carriage 294. Gripping fingers 296L, 296R are thereby also carried on and travel with the carriage 294 between the drive pulleys 288L, 288R and the driven pulleys 290L, 290R, while also being selectively movable toward and away from the web 36 longitudinal normal traversing plane 202 for thereby selectively clamping therebetween/gripping the longitudinal edge portions 62L, 62R of the web 36. Gripping fingers 296L, 296R and pneumatic cylinders 298L, 298R are sometimes collectively referred to herein as a “gripper” 296. Gripping fingers 296L, 296R include respective gripping faces 300L, 300R opposing each other and forming a web receiving gap 302 therebetween when the pneumatic cylinders 298L, 298R are retracted. Gripping finger faces 300L, 300R are each provided with a rear raised contact face 304 and forward raised gripping ribs 306. As best seen in
In operation, during or after the bags 58 have been opened and filled with bulk material 68 and while the downstream opposing rollers 256L, 256R are compressed and prevent longitudinal movement of the web longitudinal edge portions 62L, 62R, the toothed belts 292L, 292R are driven for thereby moving the gripping fingers 296L, 296R adjacent the bag opening and closing assembly 24 whereat the web longitudinal edge portions 62L, 62R of the bag under the bag opening and closing assembly 24 extend partially downstream beyond the downstream opposing rollers 256L, 256R. The web longitudinal edge portions 62L, 62R extending partially beyond the rollers 256L, 256R is thereby received in the web receiving gap 302 between the gripping fingers 296L, 296R. Pneumatic cylinders 298L, 298R are then extended moving the gripping fingers toward the web 36 longitudinal normal traversing plane 202 and against each other thereby clamping/gripping the web longitudinal edge portions 62L, 62R between the gripping finger forward raised gripping ribs 306. The gripping fingers 296L, 296R are then advanced downstream towards the heat sealing subassembly 258 as the filled bag 58 under the opening and closing assembly 24 is closed and another bag 58 is delivered thereunder and again opened. At that point, as the next bag is being opened, the clamp bars 238L, 238R are again pushed against their respective gate closure and film guide plates 232L, 232R thereby closing the film receiving channels 240L, 240R and firmly gripping the web longitudinal edge portions 62L, 62R therebetween and thereby stopping further advancement of the web 36 beyond the opening and closing assembly 24. See
As mentioned hereinabove, the vertically moving and horizontally conveying assembly 28 cooperates with the opening and closing assembly 24 and the pulling and sealing assembly 26 and functions to vertically support and move and horizontally convey the bags while they are being filled, closed, heat sealed closed and, finally, removed from the machine 10. As best seen in
Vertical posts 312R, 312L are slidingly received through couplings 316 which are secured to the machine horizontal lower beams 32L, 32R and upper beams 34L, 34R and are thereby all vertically movable therethrough. A bag guide bar 319L is secured to the vertical posts 312L and extends horizontally longitudinally parallel and on one side of the web 36 longitudinal normal traversing plane 202. Similarly, a bag guide bar 319R is secured to the vertical posts 312R and extends horizontally longitudinally parallel and on the other side of the web 36 longitudinal normal traversing plane 202. Vertical posts 312R. 312L are joined to one another with a horizontal plate 318. A pneumatic cylinder 320 is secured to the machine lower beams 32L, 32R and is coupled to the horizontal plate 318. Accordingly, by extending and retracting pneumatic cylinder 320, the horizontal plate 318 and vertical posts 312L, 312R along with the conveyor 310 and bag guide bars 319L, 319R are movable in unison vertically up and down as indicated by arrow 322.
The operation of the vertically moving and horizontally conveying assembly 28 is depicted in
With the conveyor 310 still in its lower position, the filled bag 58a is conveyed out of the machine 10 and bulk material 68 is dropped into the bag 58b, as diagrammatically depicted in
Thereafter, simultaneously: the pinch rollers 252L, 252R and 256L, 256R are relaxed thereby freeing the longitudinal edge portions 62L, 62R for movement; the conveyor 310 is moved upwardly as shown in
The filled bag 58b and web 36 upstream therefrom is then conveyed further downstream, as shown in
Next, bag 58b is conveyed further downstream and, simultaneously, the longitudinal edge portions 62L, 62R are pulled fully into the heat sealing subassembly 258 thereby also severing the longitudinal edge portions 62L, 62R of the bag 58b from the longitudinal edge portions 62L, 62R of bag 58c at the perforation line 66. The heat sealing assembly 258 then heat seals/fuses closed the bag walls 46L, 46R of bag 58b as described hereinabove along a heat seal/closure line 324, and the process is repeated.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.
Claims
1. An apparatus for heat seal closing vertically positioned plastic film bags comprising a pair of plastic film walls having upper terminal longitudinal edge portions, said longitudinal edge portions being proximate and parallel to one another, said apparatus comprising:
- a pair of elongate parallel heat seal bars defining a longitudinally extending heat sealing gap therebetween and selectively moveable into said heat sealing gap adjacent one another;
- a pair of gripping fingers defining a gripping gap therebetween and selectively moveable into said gripping gap adjacent one another;
- wherein said gripping fingers are selectively moveable longitudinally along said longitudinally extending heat scaling gap; and,
- wherein said bag terminal edge portions are placed in said gripping gap, said gripping fingers are moved adjacent one another and thereby clampingly grip said bag terminal edge portions, said gripping fingers are moved longitudinally along said heat sealing gap thereby pulling said bag walls within said heat sealing gap, and said heat seal bars are moved into said heat sealing gap engaging said bag walls therebetween whereby said bag walls are heat fused to one another and said bag is sealed closed.
2. The apparatus of claim 1 further comprising a pair of elongate parallel clamp bars vertically below said heat seal bars, each clamp bar positioned on opposite sides of said heat sealing gap and selectively moveable into said heat sealing gap adjacent one another, and wherein said clamp bars are moved adjacent one another and clampingly engage said bag walls after said bags walls are pulled into said heat sealing gap and prior to said heat seal bars engaging said bag walls.
3. The apparatus of claim 2 wherein said heat seal bars and gripping fingers are located downstream from a bag opening assembly whereat said bags are opened and filled with material.
4. The apparatus of claim 3 wherein said bags are linked to one another at their upper terminal longitudinal edge portions and a weakened attachment line is provided in the longitudinal edge portions between each bag and wherein, when said bag is pulled by said gripping fingers, said bag being pulled into said heat sealing gap is severed from an upstream bag at said weakened attachment line.
5. The apparatus of claim 4 wherein said weakened attachment line comprises a perforation.
6. The apparatus of claim 4 wherein each said gripping finger comprises a raised contact face, a raised gripping rib and a relief gap therebetween, and wherein, when said pair or gripping fingers are moved adjacent one another, said respective contact faces oppose each other, said raised gripping ribs oppose each other and said relief gaps oppose each other, and said bag terminal edge portions are clampingly gripped between said raised gripping ribs.
7. The apparatus of claim 6 wherein said gripping fingers are located vertically above said heat seal bars.
8. The apparatus of claim 6 further comprising at least one drive belt selectively moveable along said longitudinally extending heat sealing gap, and wherein said gripping fingers are carried on said belt and are thereby selectively moveable longitudinally along said longitudinally extending heat sealing gap.
9. The apparatus of claim 6 wherein a pneumatic cylinder is coupled to each of said gripping fingers and are actuated for thereby selectively moving said gripping fingers into said gripping gap adjacent one another.
10. The apparatus of claim 1 wherein said heat seal bars and gripping fingers are located downstream from a bag opening assembly whereat said bags are opened and filled with material.
11. The apparatus of claim 10 wherein said bags are linked to one another at their upper terminal longitudinal edge portions and a weakened attachment line is provided in the longitudinal edge portions between each bag and wherein, when said bag is pulled by said gripping fingers, said bag being pulled into said heat sealing gap is severed from an upstream bag at said weakened attachment line.
12. The apparatus of claim 11 wherein said weakened attachment line comprises a perforation.
13. The apparatus of claim 1 wherein said bags are linked to one another at their upper terminal longitudinal edge portions and a weakened attachment line is provided in the longitudinal edge portions between each bag and wherein, when said bag is pulled by said gripping fingers, said bag being pulled into said heat sealing gap is severed from an upstream bag at said weakened attachment line.
14. The apparatus of claim 13 wherein said weakened attachment line comprises a perforation.
15. The apparatus of claim 1 wherein said gripping fingers are located vertically above said heat seal bars.
16. The apparatus of claim 1 wherein each said gripping finger comprises a raised contact face, a raised gripping rib and a relief gap therebetween, and wherein, when said pair or gripping fingers are moved adjacent one another, said respective contact faces oppose each other, said raised gripping ribs oppose each other and said relief gaps oppose each other, and said bag terminal edge portions are clampingly gripped between said raised gripping ribs.
17. The apparatus of claim 1 further comprising at least one drive belt selectively moveable along said longitudinally extending heat sealing gap, and wherein said gripping fingers are carried on said belt and are thereby selectively moveable longitudinally along said longitudinally extending heat sealing gap.
18. The apparatus of claim 17 wherein said gripping fingers are located vertically above said heat seal bars.
19. The apparatus of claim 17 wherein each said gripping finger comprises a raised contact face, a raised gripping rib and a relief gap therebetween, and wherein, when said pair or gripping fingers are moved adjacent one another, said respective contact faces oppose each other, said raised gripping ribs oppose each other and said relief gaps oppose each other, and said bag terminal edge portions are clampingly gripped between said raised gripping ribs.
20. The apparatus of claim 1 wherein a pneumatic cylinder is coupled to each of said gripping fingers and are actuated for thereby selectively moving said gripping fingers into said gripping gap adjacent one another.
Type: Application
Filed: Sep 21, 2015
Publication Date: Mar 23, 2017
Applicant: Rethceif Enterprises, LLC (Ossian, IN)
Inventor: Chris Allen Honegger (Bluffton, IN)
Application Number: 14/860,307