US3676977A

US3676977A - Bag applicator method and apparatus

Info

Publication number: US3676977A
Application number: US73034A
Authority: US
Inventors: Harry Edward Rothmann; Walter Ruf
Original assignee: ST Regis Paper Co
Current assignee: Stone Container Corp
Priority date: 1970-09-17
Filing date: 1970-09-17
Publication date: 1972-07-18
Anticipated expiration: 1989-07-18

Abstract

This invention relates to a method and apparatus for applying bags to a bag filling machine and is characterized by apparatus for picking up a single bag from a stack of empty bags and positioning and holding the empty bag in a preselected position, and then transporting the bag to a bag opening and filling station wherein the sides of the bags are collapsed to cause the front and rear faces of the bag to buckle, and then they are pulled outwardly and a filling spout is introduced into the bag for discharging a quantity of material while means for settling and compacting the material in the bag are operating, and thereafter the bottom of the bag is elevated, and the bag is transported to a bag closing and sealing device.

Description

United States Patent Rothmann et al.

[54] BAG APPLICATOR METHOD AND- APPARATUS [72] Inventors: Harry Edward Rothmann, Valhalla;

Walter Rut, Spring Valley, both of NY.

[73] Assignee: St. Regls Paper Company, New York, NY.

[22] Filed: Sept. 17, 1970 [21] Appl.No.: 73,034

[52] US. Cl ..53/24, 53/63, 53/126, 53/188 [56] References Cited UNITED STATES PATENTS 2,853,842 9/1958 Vredenburg ..53/126X 51 July 18,1972

3,417,543 12/1968 Jones ..53/126 Primary Examiner-Travis S. McGehee AttorneyRaymond J. McElhannon [5 7] ABSTRACT This invention relates to a method and apparatus for applying bags to a bag filling machine and is characterized by apparatus for picking up a single bag from a stack of empty bags and positioning and holding the empty bag in a preselected position, and then transporting the bag to a bag opening and filling station wherein the sides of the bags are collapsed to cause the front and rear faces of the bag to buckle, and then they are pulled outwardly and a filling spout is introduced into the bag for discharging a quantity of material while means for settling and compacting the material in the bag are operating, and thereafter the bottom of the bag is elevated, and the bag is transported to a bag closing and sealing device.

14 Claims, 13 Drawing figures PATENTED JUL18I972 3,6763 SHEET 18F 8 INVENTORS f/w/ Mr mi PATENTED JUL] 8 I972 SHEET 5 OF 8 y Mme) fame Emma/w M9059 Fur SHEET 8 OF 8 I N VEN TORS BAG APPLICATOR METHOD AND APPARATUS This invention relates to bag filling equipment and more particularly to bag applicator apparatus, and it is particularly adapted among other possible applications for use with a pinch bottom style gusseted stepped-end, open mouth, multiwall industrial shipping bag. Such bags are generally closed by sealing a folded-over top portion of the bag by reactivation of a factory pre-applied hot melt adhesive. It should be understood, however, that this device is not limited to this style container, but can also be used with other types of open mouth shipping bags including sewn open mouth, taped over sewn and plastic bags which may be flat or gusseted, for example.

The present invention involves a novel combination of features combined in such a way as to afford a very efficient solution to many of the difficulties encountered with the prior art, as will become apparent as the description proceeds.

In view of the foregoing, this invention contemplates the provision of new and improved bag applicator apparatus which includes means for picking up a single bag from a stack of empty bags and positioning and holding the empty bag in a preselected position, and means for transporting the bag from the preselected position to a bag opening and filling station. In addition, means are provided for gripping and holding the bag in preparing for opening and filling and means are provided for introducing a filling spout into the open bag. Further,

7 means are provided for discharging a quantity of material into the bag and for settling and compacting the material contained in the bag. Means are included for elevating and positioning the bottom of the filled bag and for conveying the filled bag to a closing and sealing device.

There has thus been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and.

in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described more fully hereinafter. Those skilled in the art will appreciate that the conception on which this disclosure is based may readily be utilized as the basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that this disclosure be regarded as including such equivalent constructions as do not depart from the spirit and scope of the invention.

One embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a perspective view of bag applicator apparatus constructed in accordance with the concept of this invention,

FIG. 2 is an enlarged perspective view of a pick-off assembly for picking up a single bag from a stack or magazine of empty bags;

FIG. 3 is an enlarged perspective view similar to FIG. 2, but showing the bag partially removed from the stack of empty bags;

FIG. 4 is an enlarged perspective view of a plate and hinged gate arrangement for holding an empty bag in position prior to transit to a filling station;

FIG. 5 is an enlarged perspective view of a transporting assembly for carrying an empty bag to a filling station;

FIGS. 69 are a series of enlarged plan views showing the sequence of operations for opening the mouth of the empty bag in the filling station prior to filling;

FIG. 10 is an enlarged perspective view of a filling station showing the top of bag in engagement by a gripper mechanism;

FIG. 1 I is an enlarged perspective view of a filling station;

FIG. 12 is an enlarged perspective view of a filling station showing the feeder arrangement; and

FIG. 13 is an enlarged perspective view showing the conveying means for carrying the filled bag to a bag sealing apparatus.

In the illustrated embodiment, a bag applicator constructed according to this invention comprises a magazine indicated generally at 10, FIG. 1, for holding a stack of empty bags I2. As best seen in FIGS. 1-3, a frame 14, supporting two vacuum cups 16, is mounted for vertical movement so that at the bottom of its descent the cups are in contact with the base of the magazine 10 on which the empty bags 12 are horizontally stacked with their upper edges disposed towards the center line of the machine. A flexible chain 18 is attached to a fluid or air cylinder and piston assembly 20, FIG. 1, for raising or lowering the frame. The motion of the frame is arrested at the instant of contact with a first bag 22 in the stack, regardless of the stacks height. The controlling fluid cylinder and piston assembly always reciprocates between the full limits of its stroke, and as it starts its descent stroke it actuates a switch which opens a valve to supply vacuum to the vacuum cups, in a suitable manner. As the fluid cylinder and piston assembly reaches the limit of its stroke in the direction of descent, it actuates another switch (not shown) which reverses a valve (not shown) controlling its fluid supply, thereby causing reversal of the stroke and lifting of the first bag 22 from the stack. Travel of the fluid cylinder and piston assembly to the full limit of its opposite stroke causes contact with a switch (not shown) which engages a valve (not shown) controlling a fluid or air cylinder and piston assembly 24, FIG. 2, that causes the vacuum cup frame 14 to rotate through an arc of from a position as seen in FIG. 2 to a position as seen in FIG. 3, and then to a position as seen in FIG. 4. This rotation presents the empty bag 22 in an erect or upright position against a flat plate 26, FIG. 4, which forms part of a holding frame for the empty bag. This motion actuates another switch (not shown) which engages a valve (not shown) for controlling a fluid or air cylinder piston assembly 28, FIG. 1, thereby swinging a hinged gate 30 about 90 from its position as seen in FIG. 2 to its position as seen in FIG. 4. In its position as seen in FIG. 4, the gate 30 serves to contain and support the empty bag in an upright position. Closing of the gate actuates a switch (not shown) which causes release of the vacuum in the vacuum cups 16, thereby releasing the bag so that it drops a short distance, as indicated by the arrow 31, FIG. 5, until the bottom edge thereof contacts a ledge or stop 32, FIG. 1, so positioned as to accurately determine the vertical location of the empty bag preparatory to subsequent operations. At this time the vacuum cup frame 14 returns to its original position in readiness for the next cycle of operation.

As seen in FIG. 1, a electric motor 34, incorporating a magnetic clutch and brake, is mounted on the apparatus. The clutch, being normally engaged, through a chain drive 36, FIG. 11, drives two horizontally disposed transport V-belts 38, FIGS. 4 and 5, in a manner such as to act as a means of transport for the bag 22 in an opening and filling station indicated generally at 40, FIGS. 10-13. The transport belts 38 are mounted on transport belt frames 42 which are mounted for horizontal movement inwardly and outwardly from the center line of the machine, as by means of a fluid or air cylinder and piston assembly 44, FIGS. 4 and 5, provided for the purpose. The path of the bag throughout its movement into and out of the machine is along this center line. At the start of the automatic sequence the transport belts 38 are outwardly disposed from the center line and are thus in their open position. Closure of the gate 30 actuates the fluid cylinder and piston as sembly 44 to cause the transport belts 38 to move inwardly as indicated by the arrows 46, FIG. 5, and engage the empty bag 22. From that step, the bag is transported by the belt until the leading edge thereof makes contact with a switch 48, FIGS. 6-9, in the opening and filling station 40 which simultaneously releases the transport belt clutch and engages the brake, thereby causing the bag to come to an abrupt stop in juxtaposition to two sets of gripper mechanisms or pads 50 so disposed as to grip the sides of the empty bag 22 by closing on each other, as indicated by arrows 52, FIG. 7, at the top portion of the sides of the bag. Actuation of the gripper mechanism 50 is also initiated by the switch 48 which senses the presence of the bag in the opening and filling station. Upon closing, the gripper mechanism actuates a switch (not shown) which in turn actuates a valve (not shown) for controlling the fluid cylinder and piston assembly 44, FIGS. 4 and 5, thereby causing the transport belt frames 42 to open or shift outwardly as indicated by the arrows 53, FIG. 8, and simultaneously a fluid or air cylinder and piston assembly 54, FIG. 10, causes frames 56 supporting the gripper mechanisms to move toward each other as indicated by the arrows 58, FIG. 8. This action tends to narrow or collapse the empty bag sideways, and to cause the front and rear faces of the bag to buckle." Spring loaded vacuum cups 60 are mounted on the front and rear transport belt frames 42, respectively, FIGS. 610, to open the faces of the bag in opposite directions from each other to form an essentially round opening of the bag top. The vacuum cups are driven into contact with the front and rear faces of the bag respectively by fluid or air cylinder and piston assembly 62, FIG. 10, controlled by a valve (not shown) energized by the switch 48 which senses the presence of the bag. That is, the bag top is opened to present a desirable round opening preparatory to insertion of a product filling tube or spout by means of the vacuum cups 60 acting on the front and rear faces of the bag in cooperation with the opening action of the transport belt frames and the buckling action of the gripper mechanism, as seen in FIG. 9.

A product filling tube 64, FIG. 10, previously supported at a level above that of the bag is, by contact of the transport belt frames with a switch, (not shown) so mounted as to be actuated by these frames in their open position causing it to be lowered into the open mouth of the bag, and at a convenient point in its descent causes, through another switch, (not shown) to open a dump valve (not shown) for releasing the contents of a suitable material storage device well-known in the art.

The opening movement of the transport belt frames 42 causes a set of bag settling arms or heaters 66 to move forward, as indicated by arrow 68, FIG. 11, to straddle the filled or filling bag and oscillate it, as indicated by the arrow 70, FIG. 12, in a manner so as to alternately compress and release the sides of the bag to form it into an essentially cylindrical shape which is the most efficient shape for the retention of bulk material in such a container and for providing the optimum advantage in bag size. It will be appreciated that most, if not all, prior art packaging machines utilizing product settling or compacting features, derive the settling or compacting by vibration, generally of a low frequency high-amplitude displacement, in an up and down motion or by rapidly striking the front and rear faces of the package. Neither of these methods physically form a container to allow the product to settle efficiently but rather cause the product itself to move, and thus by repeated impact cause the container to bulge. According to the present invention the bag is at rest during the opening and filling phase and hence the beater mechanisms may be actuated the instant the bag stops and withdrawn prior to the restarting phase. They are operated during the interim dwell period to form the bag in such a manner as to rapidly materially increase the cubic volume of the bag for the most efficient retention of the product.

The beater action, the dwell of the filling spout within the bag, the opening position of the transport belt frames and the gripper frames are controlled by a suitable adjustable timing device well-known in the art. Upon completion of the optimum dwell time for the filling function, the filling spout is withdrawn from the bag, thereby actuating a switch (not shown) which causes the fluid cylinder and piston assembly 54, FIG. 10, to move the gripper mechanism or pads 50 to their positions as seen in FIG. 7 and causing actuation of a switch (not shown) which energizes a valve (not shown) to cause a fluid or air cylinder and piston assembly 72, FIGS. 11 and 12, to raise an elevator conveyor assembly 74 so constructed as to move between vertical limits defined by the length of the empty bag and the optimum elevation of a closing and sealing machine conveyor 76, FIG. ll, to provide the best support for the foreshortened filled bag during closure and sealing operations. Simultaneously, with the retraction of the grippermechanism and actuation by the same switch, the fluid cylinder and piston assembly 44, FIGS. 4 and 5, moves the transport belt frames 42, and thereby the transport belts 38 toward each other as seen in FIG. 7 to engage the bag top which is taut and straightened because of the efficient settling action of the oscillating beaters. This portion of the bag is flattened because it is above the level of the material contained in the bag. It will be appreciated that the bag top has remained at the same elevation throughout the entire opening and filling operation. Accurate control of the level and attitude of the bag is particularly important when applying pinch bottom bags or other style bags using adhesive closure systems, as any tendency towards deformation would tend toreduce the area of adhesive contact and thereby weaken the seal. Simultaneously, the heaters or settling mechanisms 66, FIGS. l I and I2, are withdrawn to their original positions behind the path of the bag. After the transport belts 38 are securely closed on the taut and flattened bag top, the gripper pads 50 are caused to be released and moved back to their positions as seen in FIG. 6, and this in turn actuates a switch (not shown) which releases the transport belt drive motor brake and re-energizes the clutch, thereby causing both the transport belts 38 and the elevator-conveyor 74 to run so that the filled bag is discharged to the closing and sealing machine conveyor 76. It will be appreciated that when the transport belts close they also engage a new empty bag positioned for such engagement in the interim period by the pick-off mechanism described hereinbefore.

It will also be appreciated that for certain installations a multiplicity of stacks of empty bags could be provided on a conveyor which is programmed to advance an adjacent stack of bags to the pick-off position upon exhaustion of a prior stack of bags, thereby providing uninterrupted automatic operation over an extended period of time.

It will thus be seen that the present invention does indeed provide an improved bag applicator apparatus which is superior in simplicity, economy and efficiency as compared to prior art such devices.

Although a particular embodiment of the invention is herein disclosed for purposes of explanation, various modifications thereof, after study of the specification, will be apparent to those skilled in the art to which the invention pertains.

What is claimed and desired to be secured by letters patent I. Bag applicator apparatus comprising means for picking up a single bag from a stack of empty bags, means for positioning and holding said empty bag in a preselected position, a bag opening and filling station, means for transporting said bag from said preselected position to said bag opening and filling station, means for detecting the presence of said empty bag at said bag opening and filling station and to stop it thereat, means for gripping and holding said bag in preparation for opening and filling, means for opening said bag, means for introducing a filling spout into the opened bag, means for discharging a quantity of material into the open bag, means for settling and compacting the material contained in the bag, means for elevating and positioning the bottom of the filled bag, and means for conveying said filled bag to a closing and sealing device.

2. Bag applicator apparatus according to claim I wherein said means for picking up a single bag from a stack of empty bags comprises a magazine for holding said stack of empty bags, a frame support mounted adjacent said magazine, vacuum cups carried by said frame, and means for vertically reciprocating said frame support.

3. Bag applicator apparatus according to claim 2 wherein said means for vertically reciprocating said frame support comprises a fluid cylinder and piston assembly, and a flexible chain connecting said fluid cylinder and piston assembly to said frame support for vertically reciprocating said frame support.

4. Bag applicator apparatus according to claim 1 wherein said means for positioning and holding said empty bag in a preselected position comprises a vacuum cup frame, vacuum cups carried by said vacuum cup frame for engaging said empty bag, and means for rotating said vacuum cup frame through an arc of about 90 degrees.

5. Bag applicator apparatus according to claim 4 wherein said means for positioning and holding said empty bag in a preselected position further comprises a flat plate disposed adjacent said preselected position, and a hinged gate which is swingable to contain said empty bag against said flat plate.

6. Bag applicator apparatus according to claim 1 wherein said means for transporting said bag from said preselected position to said bag opening and filling station comprises belt frames, two horizontally parallel V-belts mounted on said frames, means for moving said V-belts between a first position spaced apart and a second position closely spaced one from the other to hold said bag therebetween.

7. Bag applicator apparatus according to claim 6 wherein said belts are driven by an electric motor through a magnetic clutch and brake means, said clutch means being normally engaged for driving said belts and said brake means being engageable when said bag reaches said bag opening and filling station.

8. Bag applicator apparatus according to claim 1 wherein said means for gripping and holding said bag in preparation for opening and filling comprises a pair of gripper frames, gripper pads mounted on said gripper frames for engaging opposite sides of said bags respectively, to collapse the bag sideways and to cause the front and rear faces of the bag to buckle.

.9. Bag applicator apparatus according to claim 6 wherein said means for opening said bag comprise spring loaded vacuum cups mounted on said transport belt frames for opening the front and rear faces of the bag in opposite directions one from the other.

10. Bag applicator apparatus according to claim 1 wherein said means for settling and compacting the material contained in the bag comprises beaters mounted adjacent said filling station for alternately compressing and releasing the sides of the bag during filling.

11. Bag applicator apparatus according to claim 1 wherein said means for elevating and positioning the bottom of the filled bag comprises an elevator conveyor mounted adjacent said filling station and fluid cylinder piston assembly for raising and lowering same.

12. Bag applicator apparatus according to claim 1 wherein said means for conveying said filled bag to a closing and sealing device comprises an extension of the means for transporting said bag from said preselected position to said bag opening and filling stations.

13. Bag applicator apparatus comprising a magazine for holding said stack of empty bags, a vacuum cup frame mounted adjacent said magazine, vacuum cups carried by said frame for engaging an empty bag, a fluid cylinder and piston assembly, and a flexible chain connecting said fluid cylinder and piston assembly to said frame for vertically reciprocating said frame, a flat plate, means for rotating said vacuum cup frame though an arc of about 90 to bring said bag into engagement with said plate, a hinged gate which is swingable to retain said empty bag against said flat plate, a bag opening and filling station, belt frames, two horizontally disposed parallel V-belts mounted on said frames respectively, means for moving said V-belts between a first position spaced apart and a second position closely spaced one from the other to hold said bag therebetween, means for detecting the presence of said empty bag in said bag opening and filling station and to stop it thereat, a pair of gripper frames, gripper pads mounted on said gripper frames for engaging opposite sides of said bag respectively, to collapse the bag sideways and to cause the front and rear faces of the bag to buckle, spring loaded vacuum cups mounted on said transport belt frames for opening the front and rear faces of the bag in opposite directions from each other, means for introducing a filling s out into the o ened bag, a beater mounted ad acent said illing station or alternately compressing and releasing the sides of the bag during filling, an elevator conveyor disposed adjacent said filling station and means for raising and lowering same, means for conveying said filled bag to a closing and sealing device including an extension of the means for transporting said bag from said preselected position to said bag opening and filling station.

14. Method of applying a bag to a bag filling device comprising the steps of picking up a single bag from a stack of empty bags, positioning and holding said bag in a substantially vertical position with the opening thereof directed upwardly, gripping the upper portion of the bag between two belts for transporting the bag to a bag opening and filling station, engaging the opposite sides of said bag to collapse the bag sideways and to cause the front and rear faces of the bag to buckle, engaging the front and rear faces of the bag with vacuum cups for opening the front and rear faces of the bag in opposite directions one from the other, introducing a filling spout into the opened bag, alternately compressing and releas-

Claims

1. Bag applicator apparatus comprising means for picking up a single bag from a stack of empty bags, means for positioning and holding said empty bag in a preselected position, a bag opening and filling station, means for transporting said bag from said preselected position to said bag opening and filling station, means for detecting the presence of said empty bag at said bag opening and filling station and to stop it thereat, means for gripping and holding said bag in preparation for opening and filling, means for opening said bag, means for introducing a filling spout into the opened bag, means for discharging a quantity of material into the open bag, means for settling and compacting the material contained in the bag, means for elevating and positioning the bottom of the filled bag, and means for conveying said filled bag to a closing and sealing device.

2. Bag applicator apparatus according to claim 1 wherein said means for picking up a single bag from a stack of empty bags comprises a magazine for holding said stack of empty bags, a frame support mounted adjacent said magazine, vacuum cups carried by said frame, and means for vertically reciprocating said frame support.

9. Bag applicator apparatus according to claim 6 wherein said means for opening Said bag comprise spring loaded vacuum cups mounted on said transport belt frames for opening the front and rear faces of the bag in opposite directions one from the other.

13. Bag applicator apparatus comprising a magazine for holding said stack of empty bags, a vacuum cup frame mounted adjacent said magazine, vacuum cups carried by said frame for engaging an empty bag, a fluid cylinder and piston assembly, and a flexible chain connecting said fluid cylinder and piston assembly to said frame for vertically reciprocating said frame, a flat plate, means for rotating said vacuum cup frame though an arc of about 90* to bring said bag into engagement with said plate, a hinged gate which is swingable to retain said empty bag against said flat plate, a bag opening and filling station, belt frames, two horizontally disposed parallel V-belts mounted on said frames respectively, means for moving said V-belts between a first position spaced apart and a second position closely spaced one from the other to hold said bag therebetween, means for detecting the presence of said empty bag in said bag opening and filling station and to stop it thereat, a pair of gripper frames, gripper pads mounted on said gripper frames for engaging opposite sides of said bag respectively, to collapse the bag sideways and to cause the front and rear faces of the bag to buckle, spring loaded vacuum cups mounted on said transport belt frames for opening the front and rear faces of the bag in opposite directions from each other, means for introducing a filling spout into the opened bag, a beater mounted adjacent said filling station for alternately compressing and releasing the sides of the bag during filling, an elevator conveyor disposed adjacent said filling station and means for raising and lowering same, means for conveying said filled bag to a closing and sealing device including an extension of the means for transporting said bag from said preselected position to said bag opening and filling station.

14. Method of applying a bag to a bag filling device comprising the steps of picking up a single bag from a stack of empty bags, positioning and holding said bag in a substantially vertical position with the opening thereof directed upwardly, gripping the upper portion of the bag between two belts for transporting the bag to a bag opening and filling station, engaging the opposite sides of said bag to collapse the bag sideways and to cause the front and rear faces of the bag to buckle, engaging the front and rear faces of the bag with vacuum cups for opening the front and rear faces of the bag in opposite directions one from the other, introducing a filling spout into the opened bag, alternately compressing and releasing the sides of the bag for settling and compacting the bag during filling, elevating and positioning the bottom of the filled bag and conveying said filled bag towards a bag closing and sealing device.