AU427408B2 - Apparatus for nesting bags - Google Patents

Description

27 093 71 The present invention relates generally to an apparatus for loading individual bags onto a mandril, the bags being loaded in nested relationship. In the appli- cation of bags or groups of bags to a specific end use, it is frequently desirable to provide these bags to the customer in pre-nested relationship. Nested bags or groups of nested bags are particularly desirable for use in retail supermarkets and the like, wherein space re- quirements are limited, and wherein convenient access to bags during a sequence of transactions is required. In the past, various means and techniques have been provided for loading bags onto a mandril in nested relationship. These techniques have frequently been cumbersome and time consuming, and may also require, in many instances, a separate operation for the formation of the bag, per se, and thereafter the loading of the already formed bag onto a mandril in nested relationship with a group of bags. In the present invention, means are provided for a continuous operation of bag formation, and loading of the bags onto a mandril in nested relation- ship. The apparatus of the present invention is partic- ularly adapted for use in the treatment of film materials, particularly heat weldable film materials such as poly- ethylene, polypropylene and the like. The nesting of bags formed from thin flexible films is 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.

4 274 08

27 093 /7i This nrcbler. is comcuned T.hen it is Frcposea

to load individual film bags onto a andril in nested

relationship, particularly becuase of the inability of

these flexible films to follow a distinct pattern of

motion.

In accordance with one aspect of the present

invention, means are provided for rigidly securing, handling, and

retaining the individual bags as they are moved from the

conveyor which preferably includes the means for forming

the bag, and ultimately onto a mandril in nested relationship.

The apparatus is particularly useful in connection with

and from this delivery point, the bags are carried onto a

mandril 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 side walls 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.

The present invention may provide an improved

means for the handling of film bags and for the loading

of these bags serially onto a mandril in nested relationship.

Further, within the scope of the present invention

there can be provided 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

4274 08

27 093/71 scries n's edc relations: in,

one to another.

The presecnt invention ;:ay ue embodied in an

improved apparatus for the loading of a plurality of bags

serially onto a mandril in nested relationship, one to another,

particularly wherein the bags are ihitially grasped or gripped,

and while moving, the open top of the bag i: expanded or

extended so as to provide a wide opening between the

opposed front and rear side walls of the bag, thus per-

mitting the nesting of a substantial number of bags ser-

ially on a single mandril.

In another aspect the present invention may

provide an improved technique for the continuous pick-up,

transporting; and iltimate loading of a film bag onto

a loiding mandril, 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 mandril.

The invention will now be further described, by

way of example, with reference to the accompanying drawings,

of which:-

Figure 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 up by the loading apparatus;

Figure 2 is a view similar to Figure 1, and showing

the disposition of the bag immediately upon being picked

1 4 427408

27 093 17' up by the loading apparatus of the present invention; Figure 3 is a view, also similar to Figure 1, and showing the disposition of the bag as it appears upon being loaded onto the'loading mandril; Figure 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 pick-up pin members which releasably engage the film bag from an initial pick-up disposition to a bag support- ing disposition, and finally to a release disposition; Figure 5 is a vertical sectional view taken along the line and in the direction of the arrows 5-5 of Figure 4; Figure 6 is a detail view of the individual pick- up pins as they appear during the engaging of a film bag; Figure 7 is a view similar to Figure 6, and showing the pick-up pins during the sequence of operation, immediately after the pick-up pin has entered the hole formed in the bag; Figure 8 is a view similar to Figures 6 and 7, and showing the disposition of the pick-up pins as the bag is being held in a bag supporting disposition; Figure 9 is a view similar to Figures 6 and 7, and illustrating the disposition of the upper portion of the bag as the bag structure is being received on the loading mandril; Figure 10 is a view similar to Figures 6 and 7, and illustrating the disposition of the bag as it is being released from the pick-up pins, Figure 10 showing the disposition of the bag immediately subsequent in time to the disposition shown in Figure 9;

27. 093/71 Figure 11 is a detail elevational view showing the disposition of the individual pick-up pins relative to one another, and illustrating the staggered axes; Figure 12 is a perspective view of a bag formed in a style particularly adaptable for use in the apparatus of the present invention; Figure 13 is a detail view of a cutting bar and. welding bar utilized in the bag forming portion of that apparatus shown in Figure 1; Figure 14 is a top plan view of a rack means similar to the rack means illustrated in Figure 4, and illustrating a modified form of cam follower means; and Figure 15 is a vertical sectional viewtaken along the line and in the direction of the arrows 15-15 of Figure 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 con- veyor means 11, a second conveyor means 12 arranged in continuation with the first conveyor means 11, along with 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

4 27 4 08 which is 27. 09 3 71 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 16 and 17 are positioned to form a nip zone for delivering drive energy for inter- mittant motion of the film web 15. Power is.provided for 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 15 moves through the first conveyor means, an inwardly folded gusset is formed as at 19 and 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 Figure 1. Pre-formed 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 co-pending application of Maurice E. Blais, Serial No. 617,377, filed February 20, 1967, now Patent 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 Figure 12, a first

S093 .7 pair of holes formed by lhe punch 25 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 Figure 1, and with attention also being directed to Figure 13, it will be seen that the welding and cutter bar assembly generally designated 35 comprises a reciprocably 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 respectively. As an alternative, a transversely moving flying knife may be employed to perform the cutting operation. As indicated in Figure 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 Figure 12, the bag 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. As will be apprecia d, :r purposes of operation, that the speed of the conveyor 50 is adjusted so as to match the speed provided by the draw rolls 16 and 17, the drive of conveyor 50 preferably being intermittent so as to carry the individual bags, as formed, to a pre- determined 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 pick-up 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 Figures 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 pick-up pins while the bags are in substantially the disposition shown at Figure 1. Turning now to the details of the second conveyor means, this portion of the apparatus includes two super- imposed pairs of endless belts or chains, the first pair including endless belts 62 and 63, the second pair in- cluding 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

4274 08

27. 093 7 Figures 4 and 5, these racks, in turn, being provided with axially rotatable pick-up pins which are adapted to engage the appropriate surfaces of the individual bag members, the engaging. surfaces being, for purposes of this 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 pick-up area, thus presenting a more uniform surface for ultimate pick-up by the indiv- idual pins. For a better understanding of the structure of the racks and pick-up pins, particular attention is directed to Figures 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 pick-up 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 pick-up pin assembly and locking bar being designed for Geneva drive rotational motion.

27. 09 3/71 Referring now to the pick-up pin assembly,72, this assembly includes an upper flanged drive plate which has a bore formed centrally therein, for accommod- ating the pick-up 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 pick-up pin generally designated 79, the pick-up pin 79 being further provided with a bag supporting portion 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 Figure 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 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 journalled for rotation with supporting shaft 87. Plate 86 is further provided with a stud 88 which is effectively cammed into the disposition shown in phantom in Figure 4 by cam 89, thus permitting intermittent arcuate rotation of the drive plate 75, the rotation being followed in time by an inter- mittent locking of the drive plate 75, the return rotation

-11- 427 4 08

27. 09 3 71 being accomplished by spring member 86a. It is this intermittent rotation and locking which permits the bag supporting portion 80' of the pick-up pin 79 to perform its function in the entire operation. Attention is now directed to Figure 6 of the drawings, with continued attention being directed to Figures 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 Figure 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 side walls of the bag. As is indicated in Figure 6, the pick-up pin is arranged in the "pick- 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 is while it is in this position, that it effectively "rocks" into engagement with the holes formed in the bag as shown in Figure 12 at 30 and 31. With the pin 79 effectively engaging the bag, and with the simult- aneous release of the welding and cutting bar assembly the bag is permitted to advance along the extent of the second conveyor means. Immediately upon leaving the initial pick- up disposition, a situation such as is illustrated in Figure 7 occurs, with the bag supporting portion 80, of the pin 79 underlying the gussetted portion of the bag member as shown in Figure 12, the pin extending through the holes 30 and 31. It will be apparent at this point, that similar pick-up pins are provided for the mated

-12- 427 4 08

2 0 317' 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 pick-up station, and upon achieving a slight advance along the machine direction, the individual bag supporting portions of pick-up pin 79 are advanced, or rotated 900 from the pick-up disposition, to achieve the position shown in Figure 8. This disposition is retained until the system reaches or encounters the unloading or discharge statibn further downstream. Particular attention is now directed to Figure 9 of the drawings, again, with attention continued on Figures 2, 4 and 5; Figure 9 illustrating the 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 Figure 3 of the drawings, with continued attention being directed to Figure 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 con- tacted so as to open the locking bar assembly, and permit of arcuate motion of the pick-up pin 79, whereupon the disposition shown in Figure 10 is achieved, The disposition shown in Figure 10 is held by the bag, and with the pick- up pins in the release disposition, the bag is readily removed from the second conveyor means and thus deposited

-13- 427408

27T0 93 71 Securely onto the nesting station such as is defined by the tongues 90 and 91. Attention is-now directed to Figure 11 of the drawings wherein the'staggered axes for the individual pick-up pin assemblies is illustrated. The purpose of staggering these axes is to permit the individual1 pins to initially !'pick- up" the forad or leading edge of the bags, 49d 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 wit,~ the staggered axes. Although the present assembly has been shown With a gripping means formed from a pair of coaxial bores, it ill 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 20 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 Figures 14 and of the drawings wherein a modified form of rack means is illustrated. The rack means generally designated 100 ,comprises a frame roember 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

-14- -4-4.274 0.9

27 093/71 is provided with laterally positioned or mounted pick- up pin drive means generally designated 102 and 103, these drive means including a cam member or index star 104 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 pick-up pins having a shank portion 106 along with a bag supporting tip portion 107. 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 105 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

S2 7.4 08

9 3' pin or the like which toistitutes 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,

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.

-16- 4-27 4 08

27.09 3/71 CLAIMS DEFINING THE IN';ENTION ARE AS FOLLOWS.-

1. Abparatus for nesting bags havip an open top opposed end .alls, opposed front and rear side walls, and a bottom v:all, said apparatus comprising: first conveyor means having bag treatment means for forming a plurality of gripping surfaces on opposed surfaces of said side walls and at points adjacent the edge surfaces of said side walls and adjacent the open top, and being arranged to deliver said bags with gripping surfaces to a discharge station; elongated second conveyor means with pick-up means for releasably engaging the bags at said discharge station 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 pick-up means to said nesting station; a nesting station comprising a tongue means adjacent the end of the second conveyor and with an axis extmding generally in a plane intersecting the longitudinal ,axis of the second conveyor for nesting the bags, and with a forward abutment surface disposed generally transversely of said central axis; and

release actuation means responsive to the location of said pick-up means at a predetermined position along the second conveyor and arranged to release said pick-up means from said gripping surfaces as the forward

motion of the bag retained by said pick-up means is 'restrained by contact with said abutment surface.

1 2. he apparatus for nesting bags as defined in

4 27 A 08

27 093 71 Claim 1 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 pick-up 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 to form 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 side walls adjacent each lateral edge thereof and adj.acent the open top of said bag, and wherein said pick- up 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 side wall and its adjacent gusset portion only. .The apparatus as defined in Claim 4 being part- icularly 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 side wall-gusset portion pairs of said bags.

427408

6. The apparatus ss ned in Claim 1 bqing particularly characterized in that the bag treatment means is arranged to provide 7rirpin surfaces comprising at least one punched hole; and said pick-up nmns comprises a pick-up pin having a -shank portion and a bag supporting portion, the bag supporting portion having an axis disposed generally parallel to but spaced transversely outwardly from the longitudinal axis of said second conveyor.

7. The apparatus as defined in Claim 6 being partialarly characterised in that a plurality of said pick-up pins are provided and supported by a pair of racks arranged in oppositely disposed relqtionship 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.

427 4 08

27' 093 71 8. The apparatus as defined in Claim 6 being particularly characterized in that:

the axis of the shank portion of each

pick-up pin is disposed generally normal to both the axis of said bag supporting portion and the axis of said second conveyor; and means are provided to dispose the bag supporting portion of said pick-up pin in a plurality of arcuately spaced stable dispositions, including; a pick-up 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; a bag supporting disposition with the bag supporting axis being disposed generally transversely to the second conveyor axis; and

20 4 27 4 08

Claims (2)

1. 27 093 /71 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. The apparatus as defined in Claim 9 being particularly characterized in that said pick-up 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 pick-up 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 pick-up pin in a plurality of arcuately spaced stable dispositions, including:

   a pick-up 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;

   27 093171 a bag supporting disposition with the bag supporting axis being disposed generally trans-

   versely to the second conveyor axis; and 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: first cam means are provided for disposing said bag supporting portion in a bag pick-up disposition as the pin enters the holes formed in the bag; second cam means are provided for rotating said bag supporting portion to a bag supporting dis- position immediately after picking up the bag; and third cam means are provided for rotating said bag supporting portion to a release disposition as the bottom wall of the e(gaged bag approaches the abut- ment surface of said nesting station.

   4274 08

   27 09 3 71 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 side walls to permit a plurality of bags to engage said tongue.

   Apparatus for nesting bags substantially as herein

   described with reference to the accompanying drawings.

   DATED this 24th day of July, 1972.

   G.T. SCHJELDAHL COMPANY

   By their Patent Attorney

   GRIFFITH, HASSEL FRAZER.

   23 j4 7 4 08

   2?7 O3! 7

   72 76FlE '9 79 71

   31 8

   rlC 7

   FIE 8 FI3

   ILlE

   1 25 4 27 4 08

   2 7 19'7

   rug" I

   FIVIgf

   111712?

   rIE-ij

   42 74 C"S
2. 2.09 3/71

   13

   1 29 42 740 8

   2"1 og.3j T

   L2

   kFlW2,

   4 27 4 0-