US3783580A

US3783580A - Close fitting article packaging system

Info

Publication number: US3783580A
Application number: US00295949A
Authority: US
Inventors: V Raudys
Original assignee: Union Carbide Corp
Current assignee: Viskase Corp
Priority date: 1972-10-10
Filing date: 1972-10-10
Publication date: 1974-01-08
Anticipated expiration: 1991-01-08
Also published as: FR2202006B1; JPS5236477B2; NL173376C; DE2350590A1; NL7313879A; AR196283A1; GB1446561A; BE805845A; AU6115373A; CH585123A5; SE404784B; FR2202006A1; JPS4972082A; AU475948B2; BR7307829D0; IT996799B; CA1000247A; NL173376B

Abstract

Stacked wicketed flexible bags are air-opened sequentially one at a time at a packaging station, product being packaged is directed into each bag under a pendant product-contoured guide which shapes and holds the bag upper ply and the closely fitted product filled bag is pulled from the wicket.

Description

United States Patent 91 Raudys [In 3,783,580 [451 Jan. 8, 1974 [75] Inventor:

[ 1 CLOSE FITTING ARTICLE PACKAGING SYSTEM Vytas Andrew Raudys, Chicago, 111.

[73] Assignee: Union Carbide Corporation, New

York, NY.

22 Filed: 0ct.l0,1972

21 Appl.No.:295,949

' [52] US. Cl 53/29, 53/189, 53/385 [51] Int. Cl B65b 43/36 [58] Field of Search 53/29, 386, 385, 53/189, 190, 35, 36, 191

[56] References Cited UNITED STATES PATENTS 1/1970 Burford 53/386 X 4/1970 Noyes et a]. 53/385 X 3,590,553 7/1971 Formo 3,715,857 Fronczak 53/189 X Primary Examiner -Travis S. McGehee Assistant Examiner-Horace M. Culver Attorney-Paul A. Rose et al.-

[57] ABSTRACT Stacked wicketed flexible bags are air-opened sequentially one at a time at a packaging station, product being packaged is directed into each bag under a pendant product-contoured guide which shapes and holds the bag upper ply and the closely fitted product filled bag is pulled from the wicket. I

8 Claims, 9 Drawing Figures PATENTEDJAR emu SHEET 2 0F 3 CLOSE FITTING ARTICLE PACKAGING SYSTEM The present invention relates to a method and apparatus for sequentially opening flexible packaging bags one at a time from a stacked supply of bags, filling each opened bag with a close fitted product to be packaged and removing the close fitted product filled bag from atop the stacked supply to permit opening and filling of the next bag, and more particularly to a method and apparatus for close fitted bag filling operations which includes opening the bags automatically with an air stream, guiding products to be packaged into the opened bags under a pendant product-contoured guide means which shapes and holds the upper ply of each bag being filled while holding the stacked supply of bags by pressure on a wicket having legs which pass through holes in the lower ply of each bag in the stack down into wicket sockets in the apparatus, and removing the close fitted product filled bag from atop the stacked bag supply by pulling it against the wicket legs to shear the bag material from the wicket holes through the bag lower ply open edge. Industry has long sought to automate, insofar as possible, packaging operations involved in preparing products for the market. To the exent that'a multiplicity or series of products are alike as to size, shape and weight, fuller automation of the packaging technique is attainable. In copending application Ser. No. 173,960 filed Aug. 23, 1971 and assigned to the same assignee as this application, there is described a semiautomatic method and apparatus for packaging food products, particularly meat articles, where the products to be packaged, while not exactly alike in a series as to size, weight, and shape, are sufficiently similar in these respects to be packaged one at a time in bags of the same size and material from a bag supply source. The basic technique in the aforesaid copending application involes air opening the bags one at a time, filling each opened bag with an article to be packaged through expandable guide means which intrude into the open bag and accommodate to the size and shape of a product being packaged while holding the stacked supply of bags to be filled by pressure on a wicket having legs which extend through holes in the lower ply of each bag in the stack down into sockets in the apparatus, and sequentially removing each product filled bag from atop the stacked bag supply by pulling it from the wicket. In subsequent packaging process steps not part of the invention of the aforesaid copending application nor of the present invention, air is evacuated or expressed from the product filled bag to draw it tightly down about the product and a closure of one sort or another is applied about the bag neck. The complete package article may then be beat shrunk. The packaging techniques described in the above mentioned copending application Ser. No. 173,960, it has been found on experience, are readily implemented and practiced advantageously using the so-called arc mouth, arc lipped flexible bag disclosed in copending application Ser. No. 162,376 filed July 14, 1971, in combination with the outboard spanning shouldered wickets described in copending application Ser. No. 246,629 filed Apr. 24, 1972, both of which applications are also assigned to the same assignee at this application. These bags and wickets in such use make for orderly air opening of the topmost bag only, in a stack of bags, loading each open bag to its bottom with the article being packaged, and removal of each article containing bag from the wicket and from atop the bag stack without undesired incidental production of bag scraps, random tearing, or chunking of the bag lip material. Horizontal edge restraining elements, which are a feature of the outboard spanning shouldered wicket, restrain the bag lower ply at bag edge portions outboard of the bag wicket holes during the bag inflation and filling operations. At the termination of the filling step the force of the product bottoming in the bag pulls the bag lower ply from under the bag edge restraining elements of the wicket, allowing the bag to precess up onto the wicket shoulders, where bag wicket hole edge tearing stresses are concentrated on the wicket legs.

In the aforedescribed technique, as well as in other known techniques, the bags being filled are of a fully open cross section and the volume greater than the product being packaged and are thus said to be slack filled. Slack filling techniques followed by air removal, closure and shrinking, while necessarily and satifactorily used in the packaging of articles varying in a series somewhat as to size, shape and weight, are not economical of bag material and are not necessarily imposed in th packaging of closely similar articles in a series. Slack filled bags are indeed unsatisfactory to the point of unacceptability if the bags are imprinted with or otherwise bear brand names, trademarks, ingredients information, packers identification or other indicia, since the air removal drawdown and shrinking operations, will, it can be readily appreciated, effect wrinkling, creases, overlaps and the like distortion of the bag film, weakening the adhesion of any imprinting which may have been applied, and in any case, almost invariably rendering such indicia partially or totally unreadable and useless.

With respect to the wickets used, for reasons of manufacturing economy, standardization of bulk bag packaging modes, part interchangeability, reduction of spare parts stocks, and ease of operation, it is highly desirable to have the wickets made uniform. In this regard, it is desirable that the span between wicket legs and the span or spacing between wicket bag edge restraining element s be made to respective uniform dimensions to accommodate as broad as possible a range of wicketed stacked bag width dimensions. Other problems, however, arise if the bag widths are too great or too small relative to preselected uniform wicket leg and bag edge restraining element spacings. When the wicket leg and bag edge restraining element spacings are too wide or large relative to bag width, the comparatively wide span of the bag edge restraining elements bearing on the upper surface of the lower ply of the topmost bag of the bagstack holds down too much of the lower ply, and the height of the inflated bag mouth opening, and thus the clear opening area available for filling, is adversely reduced and rendered undesirable, if not unsuitable for close fitting filling of the bag with normally square or round cross section shape products. On the other hand, when the wicket leg spacing is too narrow or small relative to the bag width, the comparatively narrow span of the bag edge restraining elements bearing on the upper surface of the lower ply of the topmost bag of the bag stack permits the inflated bag mouth to whip about from the effects of the inflation air stream, a condition patently objectionable for facile bag filling with close fitting product.

The clear opening area available for product insertion into an inflated bag mouth is, of course, affected by the extent to which the wicket bag edge rstraining elements hold flat the lower ply of the bag being filled, and, for as long as the bag lower ply edge is under the restraining elements, by the height of the wicket shoulders and the spacing between the wicket legs. Where the bags are large in opening relative to the cross section of the product being bagged as is the case in slack filling, the ratio of clear opening area to obstructed area is not too critical. With smaller bag sizes, however, even in slack filling operations, the otherwise available area of bag mouth opening which is obstructed by the wicket shoulders and legs makes the filling step difficult and cumbersome. In close fitted filling operations any degree of obstruction in maximum attainable clear opening area creates problems and lessens operational efficiency.

Up to the time of the present invention then, even with the inventions and advances hereinabove described, no completely satisfactory method and apparatus has been available to industry for the reliable and efficient semiautomatic packaging of I products into close fitting flexible bags.

With this then being the state of the art, the present invention was conceived and developed to provide for the adaptation of semiautomatic packaging systems generally and more particularly the packaging system of copending application Ser. No. 173,960, to the very close fitted packaging of a series of products of substantially uniform size, shape, and weight.

The invention also provides a technique for modifying the shape of an air opened bag mouth to conform to a close approximation of the cross section of a product being introduced into the bag in high speed semiautomatic packaging syte'ms.

The present invention further provides for an initial release of each air opened bags lower ply from beneath the hold down or restraining elements of the wicket, towards implementation of the bag mouth shaping operation and to facilitate introduction of the product being packaged into the bag.

A still further attainment of the invention is the provision of a packaging technique which permits the use of smaller flat width bag size for a given size and shape of product than heretofore possible with known means of automatic and semiautomatic packaging systems.

Another and important attribute of the invention is that it resolves the clear opening area problem discussed hereinabove, so that the clear opening area of the inflated bag mouth is maximized, permitting more case and operating flexibility in shaping the bag opening for the introduction of highly close fittd articles being packaged, and the benefits provided in this respect by the invention increase relatively as required bag width is decreased.

These and other features, attributes, and objects of the invention will be the more readily appreciated from the ensuing description and the drawingswherein:

FIG. 1 is a side elevational view showing apparatus according to the invention, mounted on a typical bag opening apparatus, at the initiation of a packaging operation,

FIG. 2 is a side elevational view of apparatus according to FIG. 1 showing a packaging operation in progress,

FIG. 3 is a sectional view of the apparatus taken along section line 3-3 of FIG. 1,

FIG. 4 is a partial plan view showing a detail of a flapper guide mounting,

FIG. 5 is a side elevational view of the FIG. 4 detail,

FIG. 6 is a free body plan view detail showing the relationship between a holding wicket and an inflated s,

FIG. 7 is a side elevational view of the FIG. 7 detail,

FIG. 8 is a free body diagrammatic sectional view showing two positions, relative to a wicket, of a blown open bag to be filled, and

FIG. 9 is a free body diagrammatic sectional view illustrating the clear opening area phenomena relative to two sizes of bags on a wicket.

In a first step, the lower ply of the uppermost bag is restrained firmly for air inflation of the uppermost bag only, by bag edge restraining means applied outboard of the wicket holesln a second step, a product contoured guide is advanced to the opened bag mouth to engage the inside of the inflated upper ply to thereby transfer and raise the bottom ply from under the restraining means to the narrowly spaced wicket shoulders innermost portion, concurrently as the bags mouth is shaped and immobilized by the product contoured guide. In a third step, the product guide is advanced further to fully expand the inflated bag to the extent the advancing product shape demands. In a final step, the product is advanced to the bag bottom and the bag lower ply is torn from the wicket legs. In general, the present invention comprehends, in apparatus for continually sequentially blow opening and filling flattened flexible arc mouth, arc lipped packaging bags from a stacked supply of such bags held by a wicket having legs extending through holes in the lower plies of the bags, a bag edge restraining element bearing vertically on the upper surface of the lower ply of the topmost bag of the stacked supply of bags, a horizontal center portion arranged to transmit vertical force to said edge restraining element, and an upwardly extending shoulder between each wicket leg and said center portion, the improvement of a close product filling bag filling guide attachment conprising, in combination, a guide shoe having an undersurface and an oversurface both contoured generally to conform to the upper surface of an article being packaged and having a leading edge and a trailing edge; a guide shoe suspension rod having an upper end, and a lower end connecting to the oversurface of the guide shoe in a manner to dispose the leading edge of the guide shoe at an elevation lower than the trailing edge thereof when said suspension rod is vertically pendant, hanger means connected to the suspension rod adjacent the upper end thereof, horizontally pivoted to swing in a vertical plane extending longitudinally centrally of the stacked supply of bags from a first position in which the suspension rod is substantially vertical and the leading edge of the guide rod is out of engagement with a blown open bag atop the stacked supply of bags, towards and into a second position in which the lower end of the suspension rod has swung through an upward arc, the leading edge oversurface of the guide shoe is in engagement with the underside of the upper ply of said blown open bag, the blown open bag has been advanced from under the bag edge restraining element of the wicket, moved upward onto shoulder portions of the wicket legs, and is held under intermediate stretched expansion by the wicket legs and the guide shoe, towards and into a third position in which the blown open bag held between the wicket legs and the guide shoe is' under ultimate stretched expansion; resilient means biasing the hanger means against movement from said first position towards said second and third positions; at least one protrusion extending upwardly from the oversurface of the guide shoe adjacent the leading edge thereof disposed to engage the open edge of the upper ply of the blown open bag and to advance the lower ply of said bag from under the edge restraining element of the wicket in the course of the movement of the hanger means from said first position towards said second position; and a mounting bracket supporting the hanger means on said apparatus.

In a specific embodiment of apparatus according to the present invention, the guide shoe is contoured to define an inverted U-shape arcuate cross section in a vertical plane transverse to the longitudinal axis of the apparatus.

The hanger means may advantageously connect to the guide shoe suspension rod through an adjustable holding means whereby the length of the suspension rod extending between the hanger means and the guide shoe may be varied to selectably raise and lower the height of the guide shoe relative to the apparatus.

The adjustable holding means described hereinabove may comprise a threaded sleeve and a clamping nut threadedly engaged with threads on the upper end of the guide shoe suspension rod.

In certain embodiments of apparatus according'to the invention, the resilient means biasing the hanger means against movement from said first position towards said second and third positions may advantageously comprise a coil spring coaxially mounted on a rotatable shaft attached to said hanger means, said shaft being that upon which the hanger means is pivotally moveably mounted.

A preferred embodiment of apparatus according to the present invention comprises two protrusions affixed to and extending upwardly and outwardly from the oversurface of the guide shoe adjacent the leading edge thereof, arranged one on each side of the connection point of the guide shoe to the guide shoe suspension rod, disposed to engage the open edge of the upper ply of the blownopen bag at two'contact points and to advance the lower ply of said bag from under the bag edge restraining of the wicket in the course of the movement of the hanger means from said second position towards said third position. v

With reference to the drawings, a packaging station provided with apparatus according to the present invention is shown generally at 11 and comprises a frame 13 pivotally mounting a housing 15 by means of trunnions 17 disposed at the rear or aft end of the apparatus which, as shown, is to the right in FIG. 1. Housing 15 mounts a blower 19 having an air discharge towards the fore end of the apparatus through a duct 21 and the housing 15 upper surface forms a platen 23 for supporting and facilitating manipulation of a product such as a meat article, to be bagged at the packaging station. The fore end of frame 13 supports a bagging platform 25, to the left as illustrated in the drawings FIGS. 1 and 2, upon which a supply of bags 27 is placed for use in the packaging operation. Bagging platform is provided at its aft end with a wicket socket boss 29 having a wicket sockets 31 drilled or otherwise formed in parallel relationship to each other at paired spacings to accommodate the legs 35 of assorted widths of a wicket 33. Stacked bags 27 are loaded onto thebagging apparatus and secured thereto by a wicket 33 of proper size to fit holes provided in the bag lower plies at the open end and to match the appropriate wicket socket pair in socket boss 29'.

Uninflated flat stacked bags 27 are disposed as shown on the bagging apparatus with open ends towards the aft end of the apparatus and closed ends towards the fore end, supported by the bagging platform 25. Each bag has an upper ply 37 and a lower ply 39 and may be formed for instance from flattened plastic or the like tubing. 'A bag style which is particularly suitable for use with the present invention is made by continual arcuate cutting across a flattened extruded polyethylene or the present invention comprises a horizontal bearing element 43 extending transversly of the longitudinal axis of the stacked supply of bags 27, connecting to bag edge restraining elements 45 extending from respective ends of the horizontal bearing element and upwardly extending shoulder members 47 connecting the respective edge restraining elements 45 each to a wicket leg.

35. The wicket illustrated is the subject of copending application Ser. No. 246,629, supra. Otherstyles of wickets can be successfully adapted to use with the present invention, it being necessary only that the wicket design include upwardly extending shoulder members and bag edge restraining means in one form or another consistent with the criteria established herein in respect of the present invention. The socalled outboard spanning shouldered wicket, however, as illustrated in the drawings, is most preferred, as will be appreciated from the ensuing discussion. In the illustrated embodiment, as in the case of practically all wickets which may be used with the present invention, all of the wicket members and elements are connectedly and integrally formed from a single piece of suitably heavy gauge wire or rod stock, usually some kind of metal such as steel. I

The air duct 21, shown in detail in FIGS. 4 and 5 of the drawings, directs a stream of bag opening air towards the open end of the topmost bag 49 of the stacked supply of bags 27 through a nozzle end 51 formed by an upwardly sloping duct bottom panel 53, duct sides 55 and a flapper guide 57 which is pivotally mounted between the duct walls in an opening which registers in assembly with a similar opening 59 in the fore end of the platen 23. The flapper guide 57 is somewhat narrower, at least for part of its length, than the opening 59 in which it is disposed and defines slots 61 through which part-of the air stream flows upwardlytowards the underside of the upper ply 37 of the inflated topmost bag 49. Flapper guide 57 also extends toward the force end of the apparatus beyond the nozzle end 51 sufficiently to intrude into the blown open topmost bag 49 when the machine is in operation to deflect the inflation air stream downward and maintain pressure onthe bag bottom. Flapper guide 57, as

shown, is formed of a flat material similar to the material of the platen 23, stainless steel sheet for instance, and is provided with turned down side edges 58 which are pivotally attached to the duct sides 55. Mounted in this manner, the flapper guide 57 can oscillate pivotally on its mountings which may be for instance hinge bolt assemblies 63 as shown in FIGS. 4 and 5 drawings. A stop 62 intruding into the duct 21 from one side 55 thereof is disposed beneath a side edge 58 of the flapper guide to limit the upward movement of the fore end of the flipper guide to a desired point within the inflated bag clear opening area.

Fixedly attached to housing and surmounting platen 23 at one side thereof is a rigid frame 65 to provide for support and mounting of the bag filling guide attachment according to the present invention. In the illustrated embodiment the frame 65 is made of heavy gauge sheet metal, stainless steel for example, formed to define a box member as viewed sectionally in FIG. 3 of the drawings, and having an extended side 65a to facilitate attachment to housing 15 by means of bolts 67 for example. Further attachment means for mounting frame 65 on the housing 15 may also comprise bolts 67 as shown holding the bottom of the frame onto the platen 23.

An angle bracket 85 is attached in cantilever fashion atop frame 65 with suitable mounting means such,as bolts 87, with a vertical leg 850 depending as shown just off the longitudinal centerline of the apparatus. The vertical leg 85a of bracket 85 is drilled to provide a bearing hole for a hanger assembly. A suspension rod hanger assembly comprising a shaft 89, a sleeve bearing 91, and a rod holder 93 is pivotally mounted in the bearing hole in vertical leg 85a and held in place by a spring housing 87 secured to the end of shaft 89 with a set screw 110. A suspension rod 99 is secured by means of threaded engagement in holder 93 and a lock nut 101, and the entire assembly is thus pivotally moveable in a vertical plane extending longitudinally centrally of the apparatus. A coil spring 103 is disposed concentrically in spring housing 87, having an extension of one end coil held in a recess of the housing 87 rear wall and an extension of the other end coil engaged in a recess in the inside face of vertical leg 850. Spring 103 is biased to maintain a rearward directed force on the suspension rod hanger assembly so that at rest the rod holder 93 is spring held against a stop 105 protruding from the outer face of vertical leg 85a of bracket 85.

A guide shoe 107 subtends and is attached to the lower end of suspension rod 99. In a preferred embodiment, guide shoe 107 is affixed to its suspension rod so that when the rod is plumb relative to the apparatus, its foremost or leading edge is at an elevation lower than its aft or trailing edge so as to present a guie shoe undersurface contact area for the product being packaged. A pair of protrusions 109 extend upwardly and outwardly from the oversurface of guide shoe 107 adjacent the leading edge thereof arranged one on each side of the connection point of the guide shoe to its suspension rod 99.

To operate the apparatus of the present invention, the bag filling guide attachment is mounted and secured to housing 15 as shown in the drawings and hereinbefore described. Slotted mounting holes in bracket 85 may be provided to permit selective fore and aft adjustment of the guide shoe 107, its suspension rod 99 and the hanger components to accommodate various lengths of product to be packaged and, towards the same purpose, the height of the guide shoe relative to platen 23 may be selectively adjusted to suit product height. The guide shoe 107 itself is contoured to approximate the upper surface shape of the product. In the illustrated embodiment the product 20 shown is a generally circular cross section meat article, a bologna for instance, and the guide shoe is contoured to an inverted U-shaped semicircular or arcuate cross section and secured to suspension rod 99 so that its undersurface makes intimate contact with an upper surface portion of each article being packaged.

The packaging machine shown is bag-loaded by rotating housing 15 upward and back on its trunnions 17 to make the wicket socket boss 29 accessible, wicketed stacked bags 27 are placed on bagging platform 25 with wicket legs 35 in place in the wicket sockets 31 and the housing is rotated back down to its operating position with a pressure foot 52 projecting downward from duct bottom panel 53 at the nozzle end 51 of air duct 21 bearing upon the horizontal bearing element 43 of wicket 33, thus holding the stacked wicketed bags in place.

When the blower 19 is started, air flow from nozzle end 51, and to some extent from slots 61, lifts the upper ply 37 of topmost bag 49 and the bag inflates to the cross sectional shape shown as BAG SHAPE A in FIG. 8 of the drawings with its lower ply 39 still secured under the edge restraining elements 45 of wicket 33. The packaging operatornow manually guides and di rects a product 20, which has arrived on the platen 23 by one means or another, beneath guide shoe 107 into contact with the undersurface thereof and pushes the product forward towards the bag during which action guide shoe 107 swings forward away from its initial or first position and towards the fore end of the machine. As the forward arcuate movement of the guide shoe proceeds towards and into what for convenience of description may be called an intermediate or second position, its oversurface leading edge engages the underside of the upper ply 37 of inflated topmost bag 49, and the protrusions 109 engage the upper ply bag edge and the bag is pulled forward and upward so that its lower ply is freed from under the edge restraining elements 45 of wicket 33. The inflated bag, which has now been moved up on to the shouldermembers 47 of wicket 33, is held there under intermediate stretched expansion between the guide shoe in its second position and the wicket legs 35 through holes 41 in its lower ply 39, and assumes the cross sectional configuration shown as BAG SHAPE B in FIG. 4 of the drawings. As the guide shoe 107 swings further forward in an arc from the second or intermediateposi'tion towards and into a final or third position, its leading edge progresses upward and its trailing edge follows arcuately, so that at or near the end of the movement to its third or final position, it assumes a substantially horizontal attitude, with the inflated bag held between the wicket legs and the guide shoe now under ultimate stretched expansion, at which point the product 20 is pushed all the way into the inflated topmost bag 49 against the closed end or bottom thereof with, if desired, sufficient force to tear the bag loose of the wicket shoulder members 47, shearing through the bag lower ply from holes 41 to the bag open edge, Alternatively the product filled bag may be grasped by the packaging operator, and torn from the wicket. In either case, the now bagged product is advanced-to the next step, whatever it may be, in the packaging oeration. As soon as the rear end of the product 20 clears from under the leading edge of guide shoe 107 in this operation, the coil spring 103 will automatically return the guide shoe, its suspension rod, and

hanger componentry to their initial or first position. As soon as the product filled topmost bag 49 is removed from atop the stack, the next bag down becomes the new topmost bag and is immediately inflated to the configuration of BAG SHAPE A as shown in FIG. 4 of thedrawings and with the guide shoe again in its original or first position, the machine is inreadiness for repetition of the packaging operation sequence hereinabove described.

During the hereinabove described operational sequence, the product 20 moves forward into the inflated topmost bag 49 sliding on the upper surface of the flapper guide 57 which extends or intrudes at its force end slightly into the bag thus acting in conjunction with the guide shoe 107 to facilitate entry of the product into the close fitting bag in a sort of double shoehom fashion.

FIG. 9 of the drawings illustrates the clear opening area phenomenon discussed hereinbefore. AREA W, shown shaded, represents the extent to which maximum attainable clear opening area is obstructed by the shoulders 47 and upper ends of wickets legs 35 connecting to the shoulders of a given wicket 33 being used. The unshaded portion of the opening in each bag shown is the clear opening area. That the given wicket 33 obstructs maximum attainable clear opening area to a greater extent with small bags than with large bags is evident from a comparison of the BAG X by BAG Y shapes illustrated. In the case of BAG'X, the larger bag, the maximum clear opening area attainable is dimin ished by approximately 15 percent while in the case of BAG Y, the smaller bag, the diminution of maximum attainable clear opening area is approximately 40 percent. Without the method and apparatus of the present mention, the close fitted insertion of product into either bag shown, BAG X or BAG Y, is hindered, the more so in the case of BAG Y, Reference to FIG. 8 of the drawingsin the light of FIG. 9, makes for ready appreciation of the solution to the clear opening area problem provided by the present invention.

Numerous alternative structures are possible and particularly useful in givensituations.Flat articles, such as bacon sides for instance, will advantageously take rectangular cross sectional guide shoes. The apparatus as shown and described can also be readily adapted to fully automated packaging operations, obviating the need for a human operator.

Many other alternative modes within the spirit of this invention will undoubtedly suggest themselves to persons familiar with the art in the light of the foregoing disclosure and it is therefore intended that this description be considered as illustrative only and not construed in any limiting sense.

What is claimed is:

I. In an apparatus for continually sequentially blow opening and filling flattened flexible arc lipped packaging bags from a stacked supply of bags held by a wicket having legs extending clear of the upper plies of the bags through holes in the lower plies of the bags, a bag edge restraining element bearing vertically on the upper surface of the lower ply of the topmost bag of the stacked supply of bags, a horizontal center portion arranged to transmit-vertical force to said edge restraining element, and an upwardly extending shoulder between each wicket leg and said center portion, the improvement of a close product fitting bag filling guide attachment comprising, in combination,

a guide shoe having an undersurface and an over surface both contoured generally to conform to the upper surface of an article being packaged, and having a leading edge and a trailing edge;

a guide shoe suspension rod having an upper end, and a lower end connecting to the oversurface of the guide shoe in a manner to dispose the leading edge of the guide shoe'at an elevation lower than the trailing edge thereof when said suspension rod is vertically pendant;

hanger means connected to the suspension rod adjacent the upper end thereof, horizontally pivoted to swing in a vertical plane extending longitudinally centrally of the stacked supply of bags from an ini-- tial position in which the suspension rod is substantially vertical and the leading edge of the guide shoe is out of engagement with a blown' open bag atop the stacked supply of bags, towards and into. a final position in which the lower end of the suspension rod has progressed through an upward arcuate locus, the leading edge oversurface of the guide shoe is in engaement with the underside of the upper ply of said'blown open bag, and said blown open bag is held in stretched expansion between the guide shoe and the wicket sholders; resilient means biasing the hanger means against movement from said initial position towards said I final position;

at least one protrusion extending upwardly from the oversurface of the guide shoe adjacent the leading edge thereof disposed to engage'the open edge of the upper ply of the blown open bag and to advance the lower ply of said bag from under the bag edge restraining element of the wicket in the course of the movement of the hanger means from said initial position towards said final position; and a mounting bracket supporting the hanger means on said apparatus. 2. An apparatus improvement according to claim 1 wherein the guide shoe is contoured to define an inverted U-shape arcuate cross section in a vertical plane transverse to the longitudinal axis of said apparatus.

3. An apparatus improvement according to claim 1 wherein said hanger means connects to the guide shoe suspension rod through an adjustable holding means whereby the length of said suspension rod extending between the hanger means and the guide shoe may be varied to selectably raise and lower the height of the guide shoe relative to the apparatus.

4. An apparatus improvement according to claim 3 wherein the adjustable holding means comprises a threaded sleeve and a clamping nut threadedly engaged with threads on the upper end of the guide shoe suspension rod. I

5. An apparatus improvement according to claim 1 wherein the resilient means biasing the hanger means against movement from'said initial position towards said final position comprises a coil spring coaxially mounted on a rotatable shaft attached to said hanger means, said shaft being that upon which the hanger means is mounted.

6. An apparatus improvement according to claim 1 comprising two protrusions affixed to and extending upwardly and outwardly from the oversurface of the guide shoe adjacent the leading edge thereof, arranged one on each side of the connection point of the guide shoe to the guide shoe suspension rod, disposed to engage the open edge of the upper ply of the blown open bag at two contact points and to advance the lower ply of said bag from under the horizontal center portion of the wicket in the course of the movement of the hanger means from said initial position towards said final position.

7. A method for continually sequentially filling blown open bags with closely fitting products, one at a time, from a stack-of flattened flexible bags held on a wicket which has legs extending clear of the upper plies of the bags through holes in the lower plies of the bags, a bag edge restraining element bearing vertically on the upper surface of the lower ply of a bag atop the stacked supply of bags, a horizontal center portion disposed to transmit bag restraining vertical force to said bag edge restraining element, and an upwardly extending shoulder between each wicket leg and said center portion, which method includes the steps of applying a distributed area force to the undersurface of the upper ply of a blown open wicket held bag,

directing said force upwardly and in a direction of product advance into the bag until the bag lower ply is removed from under the edge restraining element, up into the wicket shoulders and held in an intermediate stretched expansion between the force application area and the wicket while concurrently advancing a product towards the blown open bag,

continuing the application and direction of said force until the blown open bag is held in an ultimate stretched expansion between the force application area and the wicket while concurrently advancing the product into the blown open stretched bag,

advancing the product completely into the bag, re-

moving the force, and

tear removing the filled bag from the wicket.

8. The method of claim 7 in combination with the step of applying a supplemental force to the open edge of the upper ply of the blown open bag in the direction of product advance.

' a: a w

Claims

1. In an apparatus for continually sequentially blow opening and filling flattened flexible arc lipped packaging bags from a stacked supply of bags held by a wicket having legs extending clear of the upper plies of the bags through hOles in the lower plies of the bags, a bag edge restraining element bearing vertically on the upper surface of the lower ply of the topmost bag of the stacked supply of bags, a horizontal center portion arranged to transmit vertical force to said edge restraining element, and an upwardly extending shoulder between each wicket leg and said center portion, the improvement of a close product fitting bag filling guide attachment comprising, in combination, a guide shoe having an undersurface and an over surface both contoured generally to conform to the upper surface of an article being packaged, and having a leading edge and a trailing edge; a guide shoe suspension rod having an upper end, and a lower end connecting to the oversurface of the guide shoe in a manner to dispose the leading edge of the guide shoe at an elevation lower than the trailing edge thereof when said suspension rod is vertically pendant; hanger means connected to the suspension rod adjacent the upper end thereof, horizontally pivoted to swing in a vertical plane extending longitudinally centrally of the stacked supply of bags from an initial position in which the suspension rod is substantially vertical and the leading edge of the guide shoe is out of engagement with a blown open bag atop the stacked supply of bags, towards and into a final position in which the lower end of the suspension rod has progressed through an upward arcuate locus, the leading edge oversurface of the guide shoe is in engaement with the underside of the upper ply of said blown open bag, and said blown open bag is held in stretched expansion between the guide shoe and the wicket sholders; resilient means biasing the hanger means against movement from said initial position towards said final position; at least one protrusion extending upwardly from the oversurface of the guide shoe adjacent the leading edge thereof disposed to engage the open edge of the upper ply of the blown open bag and to advance the lower ply of said bag from under the bag edge restraining element of the wicket in the course of the movement of the hanger means from said initial position towards said final position; and a mounting bracket supporting the hanger means on said apparatus.

2. An apparatus improvement according to claim 1 wherein the guide shoe is contoured to define an inverted U-shape arcuate cross section in a vertical plane transverse to the longitudinal axis of said apparatus.

4. An apparatus improvement according to claim 3 wherein the adjustable holding means comprises a threaded sleeve and a clamping nut threadedly engaged with threads on the upper end of the guide shoe suspension rod.

5. An apparatus improvement according to claim 1 wherein the resilient means biasing the hanger means against movement from said initial position towards said final position comprises a coil spring coaxially mounted on a rotatable shaft attached to said hanger means, said shaft being that upon which the hanger means is mounted.

7. A method for continually sequentially filling blown open bags witH closely fitting products, one at a time, from a stack of flattened flexible bags held on a wicket which has legs extending clear of the upper plies of the bags through holes in the lower plies of the bags, a bag edge restraining element bearing vertically on the upper surface of the lower ply of a bag atop the stacked supply of bags, a horizontal center portion disposed to transmit bag restraining vertical force to said bag edge restraining element, and an upwardly extending shoulder between each wicket leg and said center portion, which method includes the steps of applying a distributed area force to the undersurface of the upper ply of a blown open wicket held bag, directing said force upwardly and in a direction of product advance into the bag until the bag lower ply is removed from under the edge restraining element, up into the wicket shoulders and held in an intermediate stretched expansion between the force application area and the wicket while concurrently advancing a product towards the blown open bag, continuing the application and direction of said force until the blown open bag is held in an ultimate stretched expansion between the force application area and the wicket while concurrently advancing the product into the blown open stretched bag, advancing the product completely into the bag, removing the force, and tear removing the filled bag from the wicket.