US 3595139 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
United States Patent Richard C. Adams West Harrington, 11.1.;
Thomas J. Monahan, Swansea, Mass.; George A. Picotte, Johnston, 11.1.
 Inventors 2|1 Appl. Nb. 842,972
 Filed July 18, 1969  Patented July 27, 1971  Assignec G. T. Schjeldahl Company Northfield, Minn.
 APPARATUS FOR NESTING BAGS Primary Examiner-Wayne A. Morse, Jr. Attorney-Orrin M. Haugen ABSTRACT: Apparatus for loading a series of bags onto a mandrel in nested relationship with each bag in the series being disposed inside of its next succeeding neighbor in the series, the apparatus handling the bags accomplishing the operation with both positive loading and positive release, with the release being accomplished at substantially the same point in each cycle. The apparatus includes a delivery means such as a first conveyor which delivers the individual bags to be loaded in series relationship onto a second conveyor. The second conveyor has a plurality of pickup means for releasably engaging the surface of each bag, and thereafter transporting these engaged bags in stable disposition to a predetermined discharge point. The second conveyor means is provided with means to open the bag relatively widely so as to permit the bottom of the next preceding bag to be received within the walls of the widely opened top.
APPARATUS FOR NESTING BAGS The present invention relates generally to an apparatus for loading a series of individual bags ontoa mandrel with the bags being loaded thereon in nested relationship. In the application of bags or groups of bags to a specific end use, it is frequently desirable to provide these bags to the customer in prenested relationship. Nested bags or groups of nested bags are particularly desirable for use in retailsupermarkets and the like wherein space requirements are limited, and wherein convenient access tobags during a sequence of transactions is required. Y
In the past, various means and techniques have been provided for loading bags onto a mandrel in nested relationship. These techniques have frequently been cumbersome and time-consuming, and may also require, in many instances, separate and distinct operations for the formation of the bags, per se, and for the loading of the bags onto a mandrel the bags being arranged in series nested relationship. In the present invention, means are provided for a continuous operation of bag formation, and loading of the bags as formed onto a mandrel in nested relationship. I
The apparatus of the present invention is particularly adapted for use in the treatment of film materials, particularly heat weldable film materials. suchas polyethylene, polypropylene and the like. The nesting of bags formed from thin flexible films in difficult due to the extreme flexibility of these products. In other words, the individual bags, being thin, flimsy, and flexible, are difficult to handle, manipulate, and otherwise transfer into any sort of ordered relationship. This problemis compounded when it is proposed to load a series of individual film bags onto a mandrel in nested relationship, particularly because of the inability of these flexible films to follow a distinct predictable and reproducible pattern of motion.
In accordance with the present-invention, meansare provided for rigidly securing, handling, and retaining the individual bags as they are moved from a'delivery point at the terminal end of a first conveyor, thefirst conveyor preferably including means for forming the bag, and from this delivery point, the bags are carried onto a mandrel and arranged thereon in nested relationship. The apparatus of the present invention is particularly useful in connection with bags formed with the bottom seals thereof forming or comprising'folded gussets. The folded gusset permits expansion of the opening existing between the opposed front and rear sidewalls so as to provide a widely opened top for nesting loading. If desired, means may be provided to cuff the individual bags or individual groups of bags.
Therefore, it is a principal object of the present invention to provide an improved means for the handling of film bags and for the loading of these bags serially onto a mandrel in nested relationship.
It is a further object of the present invention to provide an improved technique for the handling of a series of individual film bags in an in-line process wherein the bags are formed serially in one station, and thereafter serially transferred to a loading station wherein they are loade'donto a mandrel in series nested relationship, one to another.
It is still a further object of the present invention to provide an improved apparatus for the loading of a plurality of bags serially onto a mandrel in nested relationship, one to another, particularly wherein the bags are initially grasped or gripped, and while moving, the open top of the bag is'expanded or extended so as to provide a wide opening between the opposed front and near sidewalls of the bag, thus permitting the nesting of a substantial number of bags serially on a single mandrel.
It is yet a further object of the present invention to provide an improved technique for the continuous pickup, transporting, and ultimate loading of a film bag onto a loading mandrel, the bag being picked up at the discharge end of a separate conveyor, and transferred without risk of ripping or tearing of the bag surface as it is finally loaded on the loading mandrel.
Other and further objects of the present invention will become apparent to those skilled in the art of bag making and handling upon a study of the following specification, appended claims, and accompanying drawing wherein:
FIG. 1 is a perspective view of the loading apparatus of the present invention, and illustrating, in particular, the disposition of the bags as they are being picked p by the loading apparatus;
FIG. 2 is a view similar to FIG. 1, and showing the disposition of the bag immediately upon being picked up by the loading apparatus of the present invention;
FIG. 3 is a view, also similar to FIG. I, and showing the disposition of thebag as it appears upon being loaded onto the loading mandrel;
FIG. 4 is a top plan view of a'component utilized in the loading conveyor, this being a rack means which is supported by a pair of endless belts, and which retains the pickup pin members which releasably engage the film bag from an initial pickup disposition to a bag supporting disposition, and finally to a release disposition;
FIG. 5 is a vertical sectional view taken along the line and in the direction of the arrows 5 5-5 of FIG. 4;
FIG. 6 is a detail view of the individual appear duringthe engaging of a film bag;
FIG. 7 is a view similar to FIG. 6, and showing the pickup pins during the sequence of operation, immediately after the pickup pin has entered the hole formed in the bag;
,FIG. 8 is a view similar to FIGS. 6 and 7, and showing the disposition of the pickup pins as the bag is being held in a bag supporting disposition;
FIG. 9 is a view similar to FIGS. 6 and 7, and illustrating the disposition of the upper portion of the bag as they bag structure is being received on the loading mandrel;
FIG. 10 is a view similar to FIGS. 6 and 7, and illustrating the disposition of the bag as it is being released from the pickup pins, FIG. 10 showing the disposition of the bag immediately subsequent'in time to the disposition shown in FIG.
pickup pins as they FIG. 11 is a detail elevational view showing the disposition of the individual pickup pins relative to one another, and illustrating the staggered axes;
FIG. 12 is a perspective view of a bag formed in a style particularly adaptable for usein the apparatus of the present invention;
FIG. 13 is a detail view of a cutting bar and welding bar utilized in the bag forming portion of that apparatus shown in FIG. 1;
FIG. 14 is a top plan view of a rack means similar to the rack means illustrated in FIG. 4, and illustrating a modified form of cam follower means; and
FIG. 15 is a'vertical sectional view taken along the line and in the direction of the arrows 15-15 of FIG. 14. In accordance with the preferred modification of the present invention, and with particular reference being made to Figures 1, 2 and 3, it will be seen that the apparatus generally designated 10 includes a first conveyor means 1 1, a second conveyor means 12 arranged in continuation with the first conveyor means 11, along with n a nesting or loading station generally designated 13. As has been previously indicated, the individual bags to be stacked or nested are formed in the first conveyor means 11, and discharged therefrom into the second conveyor means 12, and ultimately loaded in nested relationship in the nesting station 13.
Referring now to the details of the first conveyor means, it will be seen that this first conveyor means has a bed or other defined axis of travel for the film 15 which is moved therethrough. As will be seen from the drawings, film 15 is heat-weldable film in tubular form or configuration. In moving the film 15 through the apparatus, a pair of draw rolls l6 and 17 are ositioned to form a nip zone for delivering drive energy for iEItermittent motion of the film web 15. Power is provided f r the draw rolls from a suitable power source, not shown,(it being understood that the draw rolls are conventional in the art and as such are well known and commercially available.
As the film web moves through the first conveyor means, an inwardly folded gusset is formed as at 19 and 20, this gusset being formed by conventional plows of the type used in the film handling art, and may be, for example, of the style shown at 21 and 22 in FIG. I. Preformed gussetted tubing, which is available commercially may be used if desired. At this station, a pair of punch assemblies generally designated 23 and 24 are provided for forming holes in the walls of the bag. Specifically, the assemblies contain four punches, designated 25, 26, 27 and 28. These punches are also conventional in the art, and may be, for example, of the type disclosed and claimed in the copending application of Maurice E. Blais, Ser. No. 617,377, filed Feb. 20, 1967, now US. Pat. No. 3,465,634. As can be seen from a study of the punches 23 and 24, the punching axis of the punching heads is disposed orthogonally to the machine direction of the film web, and this permits a greater ease of handling of the film during the punching operation. The holes formed in the bag at this station are shown in some detail in FIG. 12, a first pair of holes formed by the punch being shown at 30-31, and a second pair of holes formed by the punch 26 is shown at 32-33.
With attention continuing to be directed to FIG. 1, and with attention also being directed to FIG. 13, it will be seen that the welding and cutter bar assembly generally designated 35 comprises a reeiprocable moving arm or bracket 36 which is resiliently coupled by means of springs 37 and 38 to a bar plate assembly including a shoe member 39 and a welding bar member 40. The welding bar member 40 carries a heated tip 42, and also carries, in spaced relationship thereto, a blade or shear member 43 which is adapted to cut the film at a point adjacent the weld. Suitable pads are provided for the heated tip 42 and the shear 43, as shown at 44 and 45 respectively. As an alternative, a transversely moving flying knife may be employed to perform the cutting operation.
As indicated in FIG. 1, as the film moves through the conveyor means 11, and while at dwell, it is punched at the punching stations 23 and 24, and is welded to form a sealed bottom wall, and is also severed adjacent the bottom wall by means of the welding and cutter bar assembly 35. Upon being severed, so as to form the bag structure shown in FIG. 12, the bat is supported by the short conveyor assembly generally designated 50, which has an idler roll as at 51, and a drive roll as at 52, these rolls being spanned by one or more endless belts or webs 53. Preferably, and as is conventional in the art, a plurality of spaced belts are utilized to form the web 53. It will be appreciated, for purposes of operation, that the speed of the conveyor is adjusted so as to match the speed provided by the draw rolls l6 and 17, the drive of conveyor 50 preferably being intermittent so as to carry the individual bags, as formed, to a predetermined axial or machine direction disposition.
Upon discharge from the first conveyor means 11, the individual bags are picked up and moved along the second conveyor means 12. As will be shown herein, the second conveyor means has a pickup means for releasably engaging and spreading the gripping surfaces of the bag, and when transported a suitable distance, the individual bags are released and deposited at the nesting station 13.
With particular attention being directed to FIGS. 1 and 2 of the drawings, it will be seen that the leading edge of the individual bags, as they leave the first conveyor means, are supported, if required, by a suitable resting table or surface 60-60. The leading edges of the bags are engaged by the individual pickup pins while the bags are in substantially the disposition shown in FIG. 1.
Turning now to the details of the second conveyor means, this portion of the apparatus includes two superimposed pairs of endless belts or chains, the first pair including endless belts 62 and 63, the second pair including the belts 64 and 65. As is indicated, each of the endless belts has an inner span which lies adjacent the axis of the conveyor system, and an outer span which is removed from that axis. The individual endless belts are capable of supporting racks of the type shown in FIGS. 4 and 5, these racks, in turn, being provided with axially rotatable pickup pins which are adapted to engage the appropriate surfaces of the individual bag members, the engaging surfaces being, for purposes ofthis application, referred to as "gripping surfaces." If desired, guide supports may be utilized to control the disposition of the individual endless belts or chains as they move along their individual spans. Also, if desired, a center support rod or the like may be employed for assisting the support of the center portion of the individual bags, thus preventing or eliminating a droop situation from occurring and the possible interference with the returning racks on the lower span.
If desired, for purposes of uniformity, a pressure member, such as a cantilevered or hanging sheet may be employed to compress the leading edge of the individual bags as they approach the pickup area, thus presenting a more uniform surface for ultimate pickup by the individual pins.
For a better understanding of the structure of the racks and pickup pins, particular attention is directed to FIGS. 4 and 5 of the drawings, wherein this structure is shown in detail. The individual racks are shown generally at 70, each rack including a lateral support bar or channel 71, along with a pickup pin assembly generally designated 72 at each end thereof. The system further includes a locking bar assembly shown generally at 73, the combination of the pickup pin assembly and locking bar being designed for Geneva drive rotational motion.
Referring now to the pickup pin assembly 72, this assembly includes an upper flanged drive plate 75 which has a bore formed centrally therein, for accommodating the pickup pin retaining shaft 76. Shaft 76 is suitably journaled in bearing 77 in order to accommodate free motion thereof. At the base of rod 76, a bore is formed which accommodates the shank portion 78 of the pickup pin generally designated 79, the pickup pin 79 being further provided with a bag supporting portion 80. It will be appreciated that the angular disposition of the bag supporting portion of the pin 79 assists in holding the upper edge of the bag taut, particularly as is shown in FIG. 3. Any suitable means may be employed to couple the pin 79 to the shaft 76. The upper surface of the flanged drive plate 75 is provided with four individual studs or pins designated 81, 82, 83, and 84, each of these pins being disposed so as to make contact with the surface of cam plate 85, and thus provide 90 of arcuate motion for the shaft 76 upon each cam-striking event. It is this arrangement which provides for the intermittent Geneva drive.
Referring now to the locking bar assembly 73, this assembly includes an upper resiliently biased locking lug or plate 86, biased plate 86 being carried and journaled for rotation with supporting shaft 87. Plate 86 is further 15 provided with a stud 88 which is effectively cammed into the disposition shown in phantom is FIG. 4 by cam 89, thus permitting intermittent arcuate rotation of the drive plate 75, the rotation being followed in time by an intermittent locking of the drive plate 75, the return rotation being accomplished by spring member 36a. It is this intermittent rotation and locking which permits the bag supporting portion of the pickup pin 79 to perform its function in the entire operation.
Attention is now directed to FIG. 6 of the drawings, with continued attention being directed to FIGS. 2, 4 and 5. Thus, as the individual bag unit is being discharged from conveyor means 11, and being held in approximately the disposition shown in FIG. 2, the racks 70 are approaching the surface of the individual bags, both from the upper surface and the lower surface, so as to effectively engage both the opposed front and rear sidewalls of the bag. As is indicated in FIG. 6, the pickup pin is arranged in the picl up" disposition with the bag supporting axis being disposed generally parallel to the axis of the second conveyor means, and with the tip portion thereof extending in the direction of travel of the system. It If is while it is in this position, that it effectively "rocks into engagement with the holes formed in the bag as shown in FIG. 12 at 30 and 31. With the pin 79 effectively engaging the bag, and with the simultaneous release of the welding and cutting bar assembly 35, the bag is permitted to advance along the extent of the second conveyor means. Immediately upon leaving the initial pickup disposition, a situation such as is illustrated in FIG. 7 occurs, with the bag supporting portion 80 of the pin 79 underlying the gusscted portion of the bag member as shown in FIG. 12, the pin extending through the holes 30 and 31. It will be apparent at this point, that similar pickup pins are provided for the mated bores 32, 33, as well as for bores 30A, 31A, 32A and 33A respectively. In other words, the bag is supported at four corners, or at four corner areas of the open top portion.
Immediately upon leaving the pickup station, and upon achieving a slight advance along the machine direction, the individual bag supporting portions 80 of pickup pin 79 are advanced, or rotated 90 from the pickup disposition, to achieve the position shown in FIG. 8. This disposition is retained until the system reaches or encounters the unloading or discharge station further downstream.
Particular attention is now directed to FIG. 9 of the drawings, again, with attention continued on FIGS. 2, 4 and 5; FIG. 9 illustratingthe arrangement of the bag as it is approaching the nesting station, for ultimate unloading onto the parallelly disposed tongues 90 and 91. The base of the individual tongues 90 and 91 are each provided with an abutment surface 92.
Attention is now directed to FIG. 3 of the drawings, with continued attention being directed to FIG. 9. It will be seen that as the bottom wall 93 of the bag approaches abutment surface 92, cams 95 and 96 which are similar to cams 85 and 89 in structure, are contacted so as to open the locking bar assembly, and permit 90 of arcuate motion of the pickup pin 79, whereupon the disposition shown in FIG. is achieved. The disposition shown in FIG. 10 is held by the bag, and with the pickup pins in the release disposition, the bag is readily removed from the second conveyor means and thus deposited securely onto the nesting station such as is defined by the tongues 90 and 91.
Attention is now directed to FIG. 11 of the drawings wherein the staggered axes for the individual pickup pin assemblies is illustrated. The purpose of staggering these axes is to permit the individual pins to initially pickup" the forward or leading edge of the bags, and thereafter extend or diverge these surfaces for depositing on the nesting station. If the axes were not staggered, interference between the tips of the pins could be expected, and furthermore, interference with the holes and pins could occur, with the individual pins passing through more holes than would otherwise occur with the staggered axes.
Although the present assembly has been shown with a gripping means formed from a pair of coaxial bores, it will be appreciated that a bag could be picked up by other means, such as, for example, a bore formed through only one surface of the bag, this being, of course, necessarily the outer surface. In addition, the structure has been shown with inwardly folded gussets 19 and formed in the bag structure. As will be appreciated, the bag structure may conveniently utilize outwardly folded gussets for equal purposes.
Attention is now directed to FIGS. 14 and 15 of the drawings wherein a modified form of rack means is illustrated. The rack means generally designated 100 comprises a frame member 101 which has a generally square cross section, and which is provided with suitable means for coupling to the endless belt devices. The rack 100 is provided with laterally positioned or mounted pickup pin drive means generally designated 102 and 103, these drive means including a cam member or index star 194 and a retaining or locking member 105. Member 105 is preferably square in its configuration in order to suitably hold or retain the members in predetermined stable disposition. The assemblies are further provided with pickup pins having a shank portion 106 along with a bag supporting tip portion m7. Preferably, the pins are orthogonal to the vertical axis in order to assist, aid, or otherwise retain the bag surfaces in taut form. Thus, when a bag is being held on the pin, the angular disposition appears to assist in maintaining the bag in predetermined taut form.
Arranged on opposite front and rear surfaces of the frame 101 are resilient flexible blades 108 and 109, these blades being secured at one end to the frame 101, and being free to flex in cantilever fashion at the other end. The ends flex in response to rotation of the cam follower or index star 104, and may assume the disposition shown generally in phantom at 110. The oppositely disposed flat surface of member maintain or retain the bag supporting pins in proper predetermined disposition.
In order to provide a reasonable basis for cammed intermittent rotation, the cam followers or index stars as shown at 104 are preferably formed of molded nylon, molded tetrafluoroethylene, or other similar materials which do not require lubrication. A convenient cam for driving the index star assembly may include a central pin or the like which con stitutes the support shaft for the cam, the cam element being a simple bearing or bushing element which is mounted on the central pin. Of course, other cam or index star driving devices could be utilized, s such as, for example, stationary posts, rods, or the like.
It will be appreciated that the structure shown herein is for purposes of illustration only, and mechanical equivalents of the specific examples shown may be utilized by those skilled in the art.
What we claim is:
1. Apparatus for nesting bags having an open top, opposed end walls, opposed front and rear sidewalls, and a bottom wall, said apparatus comprising:
a. first conveyor means having bag treatment means for forming a plurality of gripping surfaces on opposed surfaces of said sidewalls and at points adjacent the edge surfaces of said sidewalls and adjacent the open top, and being arranged to deliver said bags with gripping surfaces to a discharge station;
b. second conveyor means with a central axis and with pickup means for releasably engaging and spreading said gripping surfaces, said second conveyor means being disposed generally intermediate said discharge station and a nesting station, and being arranged to transfer bags engaged by said pickup means to said nesting station;
c. a nesting station comprising a tongue means with an axis generally coincidental with the central axis of said second conveyor means, and with a forward abutment surface disposed generally transversely of said central axis; and
d. release actuation means responsive to the axial position of said pickup means arranged to release said pickup means from said gripping surfaces as the forward motion of the bag retained by said pickup means is restrained by contact with said abutment surface.
2. The apparatus for nesting bags as defined in claim l. being particularly characterized in that means are provided along said first conveyor to form folded gussets on opposed end walls of said bags, and punch means are disposed laterally of said first conveyor for forming holes through at least the opposed lateral edge surfaces of said bags, and wherein said pickup means comprises hook means for engagement with the holes formed in said opposed lateral edge surfaces.
3. The apparatus for nesting bags as defined in claim 1 being particularly characterized in that means are provided along said first conveyor toform inwardly folded gussets of said opposed end walls, and punch means are disposed laterally of said first conveyor for forming holes through at least the opposed lateral edge surfaces of said sidewalls adjacent each lateral edge thereof and adjacent the open top of said bag, and wherein said pickup means comprises hook means for engagement with the holes formed in said opposed lateral edge surfaces.
4. The apparatus for nesting bags as defined in claim 3 being particularly characterized in that a pair of punch means are disposed along each lateral edge of said first conveyor means for forming superimposed holes through both the sidewall and its adjacent gusset portion only.
5. The apparatus as defined in claim 4 being particularly characterized in that each pair of punch means disposed along one lateral edge of said first conveyor is arranged to form laterally spaced holes through opposed sidewall-gusset portion pairs of said bags.
6. The apparatus as defined in claim 1 being particularly characterized in that said pickup means comprises a pickup pin having a shank portion and a bag supporting portion, the bag supporting portion having an axis disposed generally parallel to but spaced outwardly from the axis of said second conveyor.
7. The apparatus as defined in claim 6 being particularly characterized in that said pickup pins are supported by a pair of racks arranged in oppositely disposed relationship to a bag within said second conveyor means, the racks being spaced from and having an axis generally transverse to the axis of said second conveyor.
8. The apparatus as defined in claim 6 being particularly characterized in that:
a. the axis of the shank portion of each pickup pin is disposed generally normal to both the axis of said bag supporting portion and the axis of said second conveyor; and
b. means are provided to dispose the bag supporting portion of said pickup pin in a plurality of arcuately spaced stable dispositions, including; 1. a pickup disposition with the bag supporting axis being disposed generally parallel to the second conveyor axis and with the tip thereof extending in the direction of travel;
2. a bag supporting disposition with the bag supporting axis being disposed generally transversely to the second conveyor axis; and
3. a release disposition with the bag supporting axis being disposed generally parallel to the second conveyor axis, and with the tip thereof extending oppositely to the direction of travel.
9. The apparatus as defined in claim 7 being particularly characterized in that each of said racks is supported by pairs of endless belts disposed generally adjacent the lateral edge of the bags, and with each of said pairs of belts having a span adjacent the axis of said second conveyor and a span remote from the axis of said second conveyor and with belt-carrying wheels at the end of each span.
10. The apparatus as defined in claim 9 being particularly characterized in that said pickup pins engage the hole formed in the bag surface as the endless belt approaches the span adjacent the axis of said second conveyor and while the bag support portion of the pickup pin is rotating arcuately toward a disposition generally parallel to the axis of said second conveyor.
11. The apparatus as defined in claim 10 being particularly characterized in that means are provided for disposing the bag support portion of said pickup pin in a plurality of arcuately spaced stable dispositions, including;
1. a pickup disposition with the bag supporting axis being disposed generally parallel to the second conveyor axis and with the tip thereof extending in the direction of travel;
2. a bag supporting disposition with the bag supporting axis being disposed generally transversely to the second eonveyor axis; and
3. A release disposition with the bag supporting axis being disposed generally parallel to the second conveyor axis, and with the tip thereof extending oppositely to the direction of travel.
12. The apparatus as defined in claim 8 being particularly characterized in that Geneva drive means are provided for rotating said shank portions, the drive means including a plurality of cams disposed along the path of travel of said shank portion and a plurality of cam followers coupled to said shank portion and arranged for axial rotation therewith.
13. The apparatus as defined in claim 12 being particularly characterized in that:
a. first cam means are provided for disposing said bag supporting portion ina bag pickup disposition as the pin enters the holes formed in the bag;
b. second cam means are provided for rotating said bag supporting portion to a bag supporting disposition immediately after picking up the bag; and
c. third cam means are provided for rotating said bag supporting portion to a release disposition as the bottom wall of the engaged bag approaches the abutment surface of said nesting station.
14. The apparatus as defined in claim 9 being particularly characterized in that the span adjacent the axis of the second conveyor diverges angularly from the plane of the tongue as the span position approaches the abutment member to spread the opposed front and rear sidewalls to permit a plurality of bags to engage said tongue.