IE39752B1 - Packaging apparatus and process - Google Patents

Abstract

1469994 Packaging in protective atmospheres CVP SYSTEMS Inc 29 May 1974 [29 May 1973] 23893/74 Heading B8C [Also in Division A2] An apparatus for packaging one or more articles 17 in a flexible, substantially gas impermeable bag C, (D) Fig. 22 (not shown), under a protective atmosphere comprises a roller conveyer 84, (302) on which the filled bag is supported in an outer box B, front and rear suction manifolds 132, 134, (324, 326) which can grip the open end of the bag and upon rearward movement of the rear suction manifold 134 open the bag to permit the introduction of snorkels 246 (306) through which the bag is evacuated and provided with its protective atmosphere, flexible pads 142, 186, (344, 368) on the opposed faces of the suction manifolds for temporarily sealing the bag about the snorkels upon forward movement of the rear suction manifold 134 towards the front suction manifold 132, and a heat-sealing member 280 and a back-up pad 148, associated with the suction manifolds, for closing the bag upon withdrawal of the snorkels 246. The front suction manifold 132 is movable from a raised position which permits manual positioning of the bag open end against the rear suction manifold 134, to a lowered position opposite the rear suction manifold. Clamps (198), Fig. 9 (not shown), (372) Fig. 27 (not shown) which are mounted on the rear suction manifold, assist in the retention of the bag until it is also gripped by the front suction manifold. The snorkels 246 which may be mounted for independent movement relative to each other, are linked to the rear suction manifold so that they are always correctly positioned relative to the bag opening. The suction manifolds, the snorkels, the heat sealing member, and the clamps are driven by pneumatic piston and cylinder assemblies, and the apparatus is controlled automatically by a pneumatic and electrical system. The height of the roller conveyer is adjustable. The protective atmosphere may comprise a carbon dioxide and nitrogen mixture at atmospheric, or slightly below, pressure. The carbon dioxide concentration is preferably 50% by volume. The bag (D) may comprise two compartments which are separable along a line of perforation, and be formed of a laminate of nylon and Surlyn (R.T.M.). [GB1469994A]

Description

39759 This Invention relates to an apparatus and satltod for packaging articles, particularly articles of the type vhich are adversely affected by oxygen, in substantially oxygen-free, gas-containing flexible 5 containers, and has especial application to the packaging of fresh neat pieces, such as fresh red meat, ir. flexible containers wherein the meat may be held for extended periods of time without having the bacteria levels on or in the meat exceed acceptable limits and without having 10 a significant adverse affect on the desired colour of the meat.

Zt is well known that there are a great number of materials that are adversely affected by the atmosphere, particularly humidity conditions and the oxygen therein. - 2 - 99752 Such material* include metals, such as precious metals, which undesirably oxidise in air, and a great variety o£ food products, such as fresh fruits and vegetables, nuts, crackers, cured meats, fresh r.eats, including poultry, beef, pork, veal, and lamb.

In the case of food products, the oxygen and tu.m-ldlty conditions have undeslred effects on the food. Particularly in the case of meat, the oxygen in the air supports the growth of bacteria on the surface of the meat, in particular, and the bacteria growth can Increase to such a point that the neat becomes 'spoiled" and/or the fat becomes rancid. There are many machines and processes known for packaging products, such as fresh and cured meats, in a wide variety of vacuumlzed, gas flusl id, and/or sealed containers of various types. Canning, for example, is a well known technique for preserving food products. In order to preserve meat, various curing and preserving techniques have been used to preserve the meat over extended periods. Well known packaging techniques, primarily for consumer purchase include placing the products in flexible bags or containers. Also, vacuumizing the container to substantially eliminate bacteria growth supporting oxygen is well known. Gas flushing with preserving gases, such as carbon dioxide, is also known. It is common to heat seal the thus vacuumlzed or gas flushed container containing sliced bacon or wieners. In essence, the preservation of foodstuffs, including fresh and cured meats, for extended periods of time is a well known and well developed art.

In the preservation of fresh red meat, it must be properly preserved from the time the animal is processed 39752 and shipped from a packing plant at least until its consumption can be predicted. Although one preserving technique is to freeze the meat, probably most of the meat sold through butcher shops and consumed in restaurants is fresh meat, not previously frozen. Freezing is can-sidered to have certain disadvantages in that the colour and taste are often considered to be adversely affected by freezing. Additionally, freezing fresh meat is generally considered to be an expensive operation, requiring expensive freezing and storage equipment and also requiring considerable use of energy during freezing and during storage.

Thus, meat which is shipped fron a packing plant is more conventionally preserved, by refrigeration, at above freezing temperatures, as about 35-50°F., until the food is prepared for serving, as in a restaurant, or until the meat is prepared for consumer purchase, as in a butcher shop.

Most of the meat shipped in bulk from a packing plant is preserved by refrigerating temperatures and not by absence of oxygen. The meat is preserved in this way so the bacteria level on or in the meat or poultry does not exceed levels which would be injurious to human health. Some of the injurious bacteria are aarobic, that is, air or oxygen Is required for growth. The absence of oxygen, however, is generally considered to actually cause discolouration of fresh red meat product and this also is an undesirable result. Some researchers have also considered that excessive concentrations of carbon dioxide cause greying or darkening of the meat, even after relatively short periods of time. Thus, fresh red meat presents two particularly difficult problems for packaging thereof, that is, excessive bacteria growth and meat discolouration. 39752 The bacteria growth and discolouration problems are even more pronounced whan retail butcher shops and restaurants "age" their -Mat for a sufficient period of tine to permit the natural ensynes of for example, beef to break dotm the cells or connective tissue until the beef is particularly tender and palatable. It is generally considered that such natural aging of beef for extended periods of time is highly preferable over artificial tenderisatlon procedures, such as injection with various proteolytic enzymes. One significant problem with natural aging of beef is that the neat ordinarily, even under refrigeration, has considerable discolouration and bacteria or mold growth on the exposed surfaces of the meat. 7Ms is because the "aging" normally takes place in a refrigerated, oxygen-containing room or cooler, resulting in bacteria growth. Before the meat can be consumed, the butcher trims off not only the mold, but also a considerable portion of the meat adjacent the mold growth. As a result, there is a considerable loss in the amount of meat which can be consumed, as compared to the original cut. This leads to increased prices for such meat.

Although various techniques. Including vacuum packaging, have been used at the retail level for preserving smaller amounts of meat, as for consumer packages of meat, bulk shipments of fresh poultry and meat have generally not Involved vacuum packaging of the product. Generally, large bulk shipments of beef or pork have been in refrigerated vehicles. Sane prior art has also suggested the inclusion of an atmosphere of protective gases, such as carbon dioxide, or nitrogen. A significant disadvantage of maintaining 39752 a controlled gaseous atmosphere In a storage compartment, aa In a butcher's cooler or In a vehicle, Is that the controls for maintaining the compartment at the desired conditions of gas level, temperature, and humidity, for example, can be quite expensive and complex. Large pieces of fresh meat have also been packaged in vacuumlzed packages. For example, beef rib sections have been packaged in such a way. One quite well known system Includes placing individual meat pieces into a flexible plastics bag, the bag is vacuumlzed and then a wire clip is placed around the gathered end of the bag. One of the disadvantages of this system is that, with the clipping arrangement, it is difficult to maintain a vacuum because the end of the bag is only gathered and the vacuum is lost. Additionally, the system is principally adapted for packaging individual meat pieces and does not adapt to packaging of larger meat pieces or to bulk packaging a plurality of relatively large pieces of meat. In the case of vacuumlzed bags, the bag is generally taut and subject to splitting or breakage, thereby losing the vacuum and making the meat therein susceptible to undue bacteria growth.

The known equipment often requires seme skill in operation. Such equipment also requires considerable floor space and usually requires a heated tunnel for shrinking the bag around the packaged product. Such heat tunnels are generally placed in a refrigerated room, causing additional undesirable expenses for maintaining the refrigerated room at the desired temperature, to offset heat from the heat tunnel, and at the same time, expenses are required for heating the heat tunnel to the desired level to offset 3 0 7 5 J the temperature of the refrigerated room. Also, in the separate packaging of individual meat plcces, there is a significant disadvantage In that labour expenses are high because each single piece requires 5 a separate vacuuaizing and sealing operation. Individual handling of each swat piece during packaging is clearly tiM and labour consuming and therefore undesirable.

The present invention contemplates the packaging of articles in flexible containers the interloztof which 10 enhance the preservation of the articles being packaged.

It is especially applicable to the packaging of fresh red meat In such a way as to enhance the shelf life thereof without excessive discolouration.

In accordance with the invention char* is prondad IS apparatus for packaging one or more articles in a flexible container having an open end, which apparatus comprises means for supporting the container with said one or more articles therein, means for relaasably gripping the container on 20 opposite sides thereof at the open end, said means being movable between open and closed positions to open and close said open end duct means movable into and out of said open end to conaaunlcate with the interior of the container; and wherein the gripping means carries 23 means for temporarily sealingly closing said open end with the duct means present in said open end and during and after removal of the duct means therefrom, the duct means being connected to means for creating a predetermin- able atmosphere within the container by the passage of gas 30 along the duct means while said open end Is temporarily closed and the apparatus further Including means for hcat- sealing said open end to close the container, - 7 - 9752 The invention may be applied to the bulk packaging of articles, such as fresh red meat and/or poultry in a flexible container with suitable gases for retarding the growth of bacteria, avoiding undesirable discolouration, and enhancing the shelf life of the packaged article*.

Even after being packaged for extended periods of time fresh red meat can have an extremely low bacteria level, far lower than acceptable standards, and yet the colour of the meat is substantially unaffected by the extended storage periods. It will be appreciated that, If the bacteria level is kept low, trinaing losses after natural aging are much reduced.

The interiors of the containers normally contain preserving gases, such as carbon dioxide. In preferred embodiments of the invention carbon dioxide is mixed with an inert gas, for example nitrogen. The proportion of carbon dioxide present does not normally exceed 50% by volume.

According to the invention, a method of packaging one or more articles in a flexible container having an open end comprises supporting the container with said one or more articles therein; gripping the container on opposite sides thereof at the open end and separating said sides from each other to hold said end open; moving duct means into the container through said open end and bringing said opposite sides together to seallngly close the open end around the duct means; applying a vacuum to the duct means to evacuate the container and subsequently feeding a gas to the container through the duct means in an amount 3 8 7 t> J sufficient to inhibit deterioration of the article or articleM, withdrawing the duct means from the container whliti maintaining said open end sealingly closed from the surroundings and thereafter heat-scaling said open end to close the container.

A preferred product of the asthod 0f the invention is a package comprising a flexible container containing one or nore articles and a gas, containing carbon dioxide, at substantially atmospheric pressure, the container being heat-sealed at one end. The carbon dioxide In the container should be at a concentration which substantially inhibits deterioration of the article or articles. Such a package of fresh red beef may be stored at refrigerating temperattires for a period of at least 15 days to prepare the beef for consumption before the colour of the meat is adversely affected or before the bacteria level exceeds an acceptable level. For storage over a period of 15-30 days, temperatures in the range 35°-50°F are recoomended.

The flexible container is preferably in a relaxed, unstretched condition. A preferred form of container, prior to packing of articles therein, comprises first and second substantially flat, coextensive panels of a heat--sealable and flexible plastics material, a heat-seal bottom portion connecting the bottoms of the panels, heat-seal side portions connecting the sides of the panels, a heat-seal portion intermediate the heat-seal side portions, the heat-seal portions defining two distinct and separable compartments with sealed sides and bottoms and open tops, and a perforation along said intermediate seal portion to permit complete separation of the compartments from each other.

In preferred apparatus according to the invention the meana for gripping opposite sides of the flexible container comprises first and second elongate members, usually in the form of manifolds, having cooperating surfaces, passages communicating with the surfaces, whereby a vacuum can be formed thereat, and means for moving the first manifold between a first position at which the manifolds and the surfaces are misaligned, and a second position at which they are laterally aligned. The second manifold can grip one side of the flexible container by means of a vacuum created at the surface thereof while the first manifold is at the second position, and means are provided for moving the manifolds towards and away from each other when the first manifold is in the second position and while the container panels are held against the manifolds by the vacuum created at the surfaces thereof.

The invention will now be described by way of example and with reference to the accompanying drawings wherein: Figure 1 is a Jront elevation view of one preferred embodiment of apparatus according to the invention; Figure 2 is an elevatlonal view of one end of the embodiment of Figure 1; Figure 3 is a rear elevatlonal view of the apparatus of Figure 1; Figure 4 is an elevatlonal view of the other end of the embodiment of Figures 1 to 3; Figure 5 is an enlarged, partially sectioned view taken along the line 5-5 of Figure 1 shoving the apparatus of Figures 1-4, prior to the time that the flexible container is vacuumlzed and sealed. - 10 - 39782 Pigure 6 is a view similar to Figure 5 with the duct means positioned within the flexible container for vacuumizing and addition of gas thereto; Pigure 7 is a partially broken, sectional view taken along the line 7-7 of Pigure 5, particularly showing the manifold members used for holding the open end of the flexible container; Pigure 8 is an enlarged sectional view taken along the line 8-8 of Pigure 7, showing the flexible container holding means in a closed position and with mechanical bag clamping means shown in the Inoperative position; Pigure 9 is a fragmentary, detailed view showing the bag clamping means in the operative position; Figure 10 is an enlarged detailed fragmentary sectional view taken along the line 10-10 of Pigure 1; Pigure 11 is a detailed view showing limit switches mounted on the duct neans, which switches are useful in the sequencing of the apparatus; Pigure 12 is a detailed, fragmentary view showing the start position before commencing the vacuumizing, gas filling and sealing of the flexible container used in our packaging process; Figure 13 19 a view similar to Figure 12, showing the front manifold in the lowered position; Figure 14 is a view similar to Figures 12 and 13, with the rear manifold moved into the forward position for grasping the open upper end of the container; Figure 15 illustrates the next step in the operation of the apparatus wherein the rear manifold is moved rearwardly and the duct means are inserted into the flexible - 11 - 3 9 7 5 2 container; Pigure 16 is a view, similar to Figures 12-15, wherein the front and rear manifolds temporarily seal the upper end of the flexible container, the duct means being inserted into the flexible container for vacuumizing and adding gas to the flexible container; Pigure 17 is a view, similar to Pigure]12-16, again showing the next operating step, wherein the duct means are removed from the flexible container following vacuumizing and addition of gas, and during the heat sealing of the flexible container; Pigure 18 is a view, similar to Pigures 12-17 following the heat sealing and showing completion of the sequencing of the apparatus and thereby completion of the packaging operation; Pigure 19 is an end view of a duct used for vacuumizing and adding gas to the flexible container; Figure 20 is a fragmentary end view of the duct of Figure 19; Figure 21 is a pneumatic flow diagram for the apparatus shown in Figures 1-20; Pigure 21A is an electrical schematic diagram of the electrical controls used in the sequencing of the apparatus; Figure 21B is another electrical schematic diagram showing the motor controls for a vacuum pump, and heat sealer heating element.

Figure 22 is a side elevatlonal, partially sectional view of another and preferred embodiment of apparatus useful for practicing our process; Pigure 2 3 is a fragmentary sectional view taken - 12 - :» :i 7 :> :: • I'.mg ch.- : ! r-.- .'1-2 1 <if Kt<iuv.- rigur«' /4 1 :i rt pi. II-. Vl'-w ■)'. .1 r : IM f - ii".! line or b.iq navlng two .1l»tlnct but -.••im r.>!-! <■ con t i . r. lng sc.'tions; Figure 2Z> i«; a fron' e 1 «-v 11 lon.i! viev ">t •. p." Apparatus e^bod 1 ed in Figure 22 Jurui.; pr vcssiru tr.d using the double bag of Figure 24; Figure 26 is a vlaw of the apparatus •..■f F1 jur*--25 at the tine the bag gripping m.«nl folds /mid the upper end of the bag In the open position lor r^ceivinq the due r-e3ns therein; Figure 27 i3 a detai Levi view shoving a pru!'«-ri t* i frr-- !-f wechani ,-al bag ~ 1 a.-r.ping Figure 28 Is a plan view of the b.r: c' >.~p .n.j rr.e^ns -.*rbodled m Figure 2? in the o ptrritlve to.; it: or.: and Figure 29 is a front e levationai view o: *h er.ccii.T-erst of Figure 22 wherein the duct r.oar..-; >;-r- show-in the operative position in a joubie ba-J riT.t.i mer, pa.-. u!arly illustrating the feature of pos : r_: on i r..'; tne Juc*" • at r.f :-;rer.t levels in the preferred er-.bod i.T.ent. deferring to F igurej1 - 2?, ^ne pr-ir -^rt--: j pp->r a • u generally 5>">, useful for practicing cur puc'tag . p.g proce^.-is shown. The apparatus 50 generally lnclu.ioi. >. pac:'<a support fr ar?e, general:'/ 52, a bag gripping isse.~hly general iy ">4, a vacuur.i sine and gas addinc lusercMy, generally 56 and a heat sealing assembly, ger.er.illy 55. The apparatus SO may be used fnr packaging a laigo . cf articles, particularly those articler. which -ire corw.cn 1 adversely affected by the atmosphere, ?uch as rietals, :r.-preoi-ius met jIs, fruits, veaetables, ;r •;'<( - 3 9 7 5 4 bread and biscuits, because of, tor example, humidity condition* and oxygen.

For purposes of simplicity, it Is to bo understood that our wthod and the apparatus SO, described 5 herein, useful for practicing our »tbod will specifically describe the packaging of fresh meats, such as fresh poultry, fresh veal, fresh pork, fresh lamb and fresh beef, such packaging being one of the principal and most Important uses of our esthod and apparatus. More specifically, the 10 description will hereinafter generally refer to the packaging and processing of fresh cut beef. Also although the invention herein is particularly useful for bulk packaging a plurality of m«at pieces. In a single container, it is to be understood that the apparatus and aathod is also very 15 useful for the packaging of single articles, such as large pieces of beef, e.g., block beef, in a single container.

In the packaging fcf meat pieces M, as seen in Figure 5 and 6, for example, the meat M is contained within ■ a flexible container C. In turn, the flexible container 20 C is contained within a self supporting, rigid outer container or corrugated box B. The structure of the flexible container C is considered important in the process, and certain requirements, particularly for the packaging of fresh red meat, are called for. Although a variety of 25 low gas permeable, heat scalable flexible containers are useful in our process, one preferred bag or flexible container C comprises a laminated, flexible, substantially flat, double panelled, plastics container, having an open upper end and three heat sealed sides. The lamination of 30 each panel comprises nylon bonded to Surlyn (DuPont trademark) , such a lamination being widely used in the meat indus- - 14 - 3 9 7 5 2 try for storage of meat. This material has the desirabl" property of low air or gas permeability and is alco hoat sealable regardless of the presence of blootJ or fat at the heat seal area. In this lamination, the nylon layer is 5 on the exterior ar.d the Surlyn layer is on the Interior so that the heat seal is between the abutting surfaces of the Surlyn layers. In one specific example of this product, the nylon layer has a thickness of about .0177 inches and the thickness of the Surlyn laysr Is in the range of 2 to 10 4 mild.

Another flexible container which has been found to be quite satisfactory is sold under the trademark Maraflex Z 284-400 Freshtuff Primal Meat Bag. This product Ib available from the American Can Company. The oxygen barrier pro-15 perties of the material are *pp:oxia*tely 5-8 milliliters/ meter squared for twenty four hours at 73°F ar.d 50* relartve humidity. The water permeability rate is approximately 2.5 grams per meter squared for twentyfour hours at 100°F and 90%relatlve humidity. Such containers are also heat 20 sealable, even in the presence of fat or blood. A bag having a flat dimension of about 32" x 41" has been found to be suitable for packaging about 50-80 pounds of fr^sh meat. The size of the bag is, of course, variable over a wide range. 25 The container B is desirably made from a conven tional collapsible corrugated box of a selected size.

One of the advantages of our method is that, with the use of the flexible containers C, the boxes B do not require any special interior coating. This is in contrast to prior 30 art corrugated containers which have been used for shlppiny and storage of meat cuts wherein a coated Interior was required and also such containers were not reusable. Sinco - 15 - 39752 the flexible container C Is In contact with the meat In the applicant's Invention, the box B not only does not need an Internal aoistureproof coating, but It is also possible to reuse the box B because the meat does not contact the interior. Avoidance of the interior coating and ability to reuse represent a considerable saving over the meat packaging techniques ut ' ~ coated containers.

Referring to Figures 1-4, the apparatus SO includes a main frame, generally 60, located above, below and to the rear of the package support frame 52. The frame 60 supports the package frame 52, the bag gripping assembly 54, the vacuuming assembly 56, and the heat sealing assembly 58. The frame 60 includes a rear frame which might Include a cabinet, generally 62, and an overhead frame assembly, generally 64. The apparatus 50 is movably supported by four caster wheels 66 mounted on the lower portion of the frame 60.

The main frame 60 includes a welded base 68 which Is constructed of hollow tubular frame members formed in a generally rectangular shape. The frame base 68 includes a pair of end pieces 70 and spaced front and rear •ecti«x»« 72 and 74. An Intermediate tubular frame section 76 is positioned substantially parallel and intermediate the frame sections 72, 74 and rigidly secured, as by welding, to the inner faces of the opposite frame end pieces 70. The main frame 60 Includes an upright frame section 78 which extends upwardly from and is fixed to the base 68 and provides rigid support for the overhead frame assembly 64, as well as for the rear frame 62. The base 68 also Includes a pair of longitudinal, spaced end frame sections 80 which project upwardly from the base 68 and - 16 - 3076a rigidly Interconnect with the upright section 78. A pair of spaced, frontwnrdly projecting transversa frame sections 82 also project upwardly from th* bane 68 and interconnect with the upright frame section .'8. The 5 frame sections 80 and 82 assist in rigidly supporting thi: upright frame section 78 and thereby the overhead frame assembly 64 in a substantially rigid condition.

The package support frame 52 is vertically movable relative to th« main frame 60. The box B containing the 10 meat M is supported on the packaqe support frame 52 and specifically rests on a longitudinally positioned roller conveyor assembly 84. The conveyor assembly 84 includes i longitudinally elongated frame 86 having side mentor* B3 which rotatably carry a plurality of transversely posit i>>nr<. 15 roller members 90 which support the box 9 and its contents.

The vertical level of the conveyor frame 86 is adjustable by an adjusting assembly, generally 92. The assembly 92 Includes a pair of crossing members 94 which are pivotally interconnected at 96. The upper end of one 20 cross member 94 is pivotally connected to one side 36 of the conveyor frame 86 while the lower end of the other cross member 94 is pivotally interconnected to the base 66 at 98. The lower end of the cross member 94 which is pivotally connected to the side 88 of the frame 86 Includes 25 a transverse support 100 which is slidably mounted on the upper portions of the front frame section 72 and of the intermediate frame section 76 of the base 68. A threaded member 102 is rotatably mounted on the underside of the frano H'-. A threaded nut 104 engages the threaded member K'2. The 30 upper end of the cross member 94, which is pivoted to the base 68, is also pivotally connected to the nut 104. A handle - 17 - 7 8 :i 106 la rigidly secured to the threaded member 102. When the handle 106 la rotated, the non-rotatable nut 104 is longitudinally and selectively moved in forward or reverse direction along the elongated threaded member 102. With this movement, the '.-rossing members 94 create a scissors type of action to vertically raise or lower the conveyor assembly 84 to the desired level.

Referring particularly to Figure 3, the rear frame 62 is rigidly connected to the main upright frame section 78. The rear frame 62 includes a pair oi upright, side caoinets 108 and 110 for enclosing a pressurised carbon dioxide tank 112, on one side of the frame 60, and • pressurised nitrogen tank 114, on the opposite side of the frame 60. An intermediate lower cabinet 116 contains a pair of pressure accumulators 118 and 120 on opposite sides. One accumulator 118 is for accumulating pressurized carbon dioxide therein and the other accumulator 120 is for storing pressurised nitrogen therein. The purpose of the carbon dioxide tank 112 ana accumulator 118 as well as the purpose of the nitrogen tank 114 and nitrogen accumulator 120 will be hereinafter described in greater detail.

The base 68 also supports a laterally positioned lower cabinet 122 which contains a vacuum pump 124. The purpose and operation of the vacuum pump 124 will also be hereinafter described in greater detail. Again, referring in particular to Figures 1-4, the overhead frame assembly 64 is generally positioned over the conveyor assembly 84 and over the base 68. The open space between the conveyor assembly 84 and the overhead frame 64 is provided for receiving the box B with its contents therein. This basic geometry of the apparatus 50 is important in packaging articles in - 18 - n o 7 y:: large quantities in relatively heavy packages as It supports such packages In a position suitable for vacuumizing and gas addition, and heat sealing operations per for.■'•■d by the apparatus. 5 The overhead frame assembly 64 generally includes a front welded frame section 126, a rear welded frame section 128, and a pair of opposed side welded frame sections 130. The frame sections 126, 128 and 130 comprise a p'urailt of longitudinal, transverse, and upright frame members which 10 are welded together to fora a rigid overhead support frame assembly 64.

The various frames and cabinets, as shown and described, in the case of meat processing are constructed of stainless steel panels and frame members so as to bo 15 readily washed down after use. Similarly, all motors and electric controls are waterproof or splash proof for the same reason .

Referring particularly to Figures 5, 6 and 7, the bag gripping section 54 is shown most clearly. The bag 2o gripping section 54 includes an elongate front manifold, generally 132, and an elongate rear manifold, generally 134, which cooperates with the front manifold 132 to hoi.', the open upper end of the flexible container C in the desired position during the vacuumizing, gas filling, and heat sealing 25 of the flexible container C. Both the front manifold 132 and the rear manifold 134 are substantially parallel with each other and have their longitudinal axes aligned with the longitudinal axis of the apparatus 50 itself. The front manifold 132 is movable in a substantially vertical direction 30 while the rear manifold 134 is movable in a substantially horizontal direction In a manner to be hereinafter described. - 19 - 397 52 The front manifold 132 includes an elongate, rigid support section 136 having longitudinal, interconnected passageways 138 located internally and extending substantially the length thereof. Pas sag €,•*-«* 1interconnect with each of a plurality of Inwardly facing openings 140 which extend substantially along the upper and lower portions of the Inwardly facing wall of the elongated support section 136 of the front manifold 132. The upper and lower walls of the opening* 140 are vertically spaced from each other and are substantially parallel with es-^ clhu. The inwardly facing wall of the front manifold 132 has elongate upper and lower flexible sealing pads 142 adhesively, but re-placeably bonded thereto. The pads 142 each include pad openings 144 which are in substantial alignment with the openings 140 in the metal support section 136. The openings 140 in the support section 136, the pad openings 144, and the passageways 138 define a manifold which connects with a flexible hose 146 which selectively communicates with a vacuum from the vacuum pump 124.

Intermediate tne pads 142, there is provided an elongated, flexible heat seal back-up pad 148 which, like the pads 142, is adh#«iv«ly but replaceably bonded to the inwardly facing wall of the front manifold 132. The back-up pad 148 is flexible to substantially the same degree as the sealing pads 142. The purpose of the flexibility for the back-up pad 148 and for the sealing pads 142 will be described hereinafter in greater detail.

The front manifold 132 is movably supported in a horizontal position and for vertical movement by a pair of fixed, upright guide rods 150 which are rigidly mounted to the front portion 126 of the overhead frame assembly 64. - 20 - 3973 2 Each of the guide rods 150 Is rigidly held in a vertical position by spaced lower and upper supports 152 and 154. As seen best,for example, in Figure 8, a support assembly 156 is rigidly secured to the front face at each end cf the 5 front manifold 132 and i3 slldably received by each of the guide rods 150 to thereby guldably support the front manifold 132, In a substantially horizontal position, for vertical, reciprocal movement. Each support asnerably 156 preferably uses two ball bushings to better assure the appropriate level 10 movement of the manifold 132. Ball bushings, sold under the trademark Thompson, have been found to be particularly satisfactory.

The vertical, reciprocal movement is imparteu to the front manifold 132 by an air cylinder assembly, generis ally 158. The air cylinder assembly 158 is secured at its cylinder end to a support bracket 160 which is fixedly secured to the front portion of the overhead frame assembly 64, as seen best in Figures 1 and 5 Because of slight angular out of vertical movement of the cylinder assembly 20 158 during operation thereof, a pivot connection 162 is provided between the assembly 158 ana the bracket 160. A support member 164 is rigidly mounted centrally of the front portion of the front manifold 132 and a piston rod 166 of the air cylinder assembly 158 is pivotally secured thereto by 25 a pin 168 to permit slicht relative movement therebetween.

At the appropriate signal, to be hereinafter described, the air cylinder assembly 158 is activated by air pressure to selectively move the front manifold 132 downwardly or upwardly, as needed. 30 The rear manifold 134, as disclosed previously, is - 21 - 39752 selectively reciprocally movablo forwardly and rearwardly. The rear manifold 134 Includes an elongate, rigid support section 170 which Is substantially parallel with the front manifold 132. The opposite ends of the support section 170 include support brackets 172, as seen best in Figures 5-7, rigidly mounted thereon. The support brackets 172 are rigidly secured to the faces of the support section 170 by bolts 174. The support section Includes Internal passageways 176 which extend for substantially the entire length of the support section *170. The passageways 176 interconnect with a plurality of frontwardly opening openings 178, which extend through spaced upper portion 180 and lower portion 182 of the elongated support section 170. A hollow space 164 is defined between the spaced upper and lower portions 180 and 182.

Upper and lower pads 186 are adhesively, but replaceably bonded to the outer face of the elongated support section 170 and are constructed of the same flexible material and in a manner similar to the flexible pads 142 which are similarly bonded to the front manifold 132. The pads 142 and 186 are made of foamed rubber. The pads 186 are bonded to both the upper and lower portions 180 and 182. Pad openings 188 are provided in the pads 186 and are in alignment with the openings 178 in the support section 170 The pad openings 188, the openings 178, and the passageways 176 define a manifold which interconnects with a flexible hose *.90 which selectively interconnects to the vacuum pump 124. Zn order that the manifolds 132 and 134 properly grip the flexible bag C, the pad openings 188 are longitudinally and vertically offset from tha pad openings in the front manifold when the manifolds are aligned as shown In Figure 6. - 22 - U97B2 The rear manifold 134 i« mounted for nubst^n-tlally horizontal movemrnt by two pairs of spaced pivot •irms 192 which are eacn pivotately »«cured to or« ot trm support bracket* 172. 'l'ho lower cndn t mo arms 192 ire each pivotally secured ai 196 to ,,,H' o1 lllv' i>i<icJcrc» 17'.'., *hn. the upper ends of the arms 192 are pivotally secured at 194 to transverse side lections 130 of the overhead frame 64 With this support arrangement, the rear manifold 134 is supported for movement in forward and reverse directions, while the outer faces of the upper and lower pads 1S6 remain in a substantially vertical position so as to properly align with the front manifold 132 to qrlp a flexible container C, as will be hereinafter described.

Referring to Figure 6, when ♦he front man.fold 132 Is in the lowered position, and when the rear manifold 134 is in the forward position, the manifolds 132 and 134 oooperate to positively hold the open upper end of the flexible container C in a closed condition. The manner of accomplishing this will be described hereinafter in greater detail. Vacuum is selectively applied by the vacuum pump 124 to the openings 188 in the rear manifold 134, the bag or container C being held in place initially by such vacuum. More specifically, the panel of the container C adjacent the rear manifold 134 is initially helri in place against the pad openings 188 by vacuum in the manifold 134. In order to positively hold the front panel of the container C, after manual positioning and after the rear panel is held by vacuum against the rear manifold 134, referring to Figures 8 and 9, a mechanical bag clamp, generally 198 is provided for positively gripping the upper ends of 397 52 both panels of the flexible container C against the upper pad 186 oZ the rear manifold 134.

The bag clamp 198 includes an air cylinder 200 which is pivotally secured by a pivot member 202 to a support arm 204. The support arm 204 Is rigidly secured to ciir support section 170 of the rear manifold 134. A piste rod 206 of the air cylinder 200 Is pivotally connect s at 208 to an arm 210 which, In turn. Is rigidly secured to one half of the hinge clamp 212. The other half of the hinge claap 212 Is rigidly secured co the support section 170, as best seen In Figures 8 and 9. When the air cylinder 200 Is activated, the rod 206 moves from the position of Figure 8 to that of Figure 9 so as to pivot the hinge clamp 212 to the position of Figure 9, and positively hold both sides of the upper end of the container C against the pad 186 until such time as the rear manifold 134 and front manifold 132 move Into proximate relationship, as shown In Figure 6.

It Is also Important, as seen best In Figure 8, that in the closed position, the openings 140 In the front manifold 132 are to be offset, as discussed above, from the openings 178 In the rear manifold 134 so that the vacuums applied against the opposite panels at the upper end of the container C are not In direct opposition. If the openings 140 and 178 are in direct alignment, the front panel of the container C is not under the proper influence of the vacuum in the front manifold 132.

Referring to Figures 5 and 6, the desired forward and reverse movement is imparted to the rear manifold 134 by an air cylinder assembly 214. The cylinder end of the cylinder assembly 214 is pivotally secured at 216 to a bracket 218 which is rigidly secured, as seen in Figure 7, - 24 - 397 02 to the central portion of a longitudinal frame member of the rear section 128 of the overhead frame .issembly 64. The piston rod 220 of the cylinder assembly 214 is pivotally secured at a pivot pin 222 to a crank arm 224. The crank arm 224,1s, at its central portion, pivotally secured to a bracket 226 which is fixedly secured to the rear the rear manifold 134. The lower end of tha crank arm 224 is pivoted to a link 228 at a pivot connection 230. The link 228, in turn, is pivotally secured at 232 to a bracket 234 which is fixed to the central position of the same frame member which carries the bracket 218. As seen in Figure 6, when the air cylinder assembly 214 is activated, the piston rod 220 moves outwardly and pivots the crank ana 224, thereby moving the rear manifold 134 to the full forward position for positively gripping the open upper end of the flexible container C in a fixed position between the manifolds. The link 228, in the position shown in Figure 6 is in axial alignment with the lower section of the arm 224 to thereby act as a stop for the rear manifold 134 in the full forward position against the front manifold 132.

As seen best in Figure 6, the vacuumizing and gas adding assembly 56 is inserted intc the flexible container C for the desired vacuumizing thereof, and gas addition thereto. The assembly 56 Is best shown in Figures 1 and 5-7, and includes a pair of laterally spaced, upright air cylinder assemblies 236. Each of the air cylinder assemblies 236 is of substantially the same construction, so reference will generally be made to only one of the air cylinder assemblies 236. Each air cylinder assembly 236 is pivotally secured at 238 to a support bracket 240 which - 25 - 387 52 is rigidly secured to the inner face of the front frame section 126 of the overhead frame assembly 64.

Each of the cylinder assemblies 236 is located substantially equidistantly from the upright, central axis of the apparatus, as seen best in Figure 1. Each cylinder assembly 236 includes a downwardly extending piston rod 242. The lover end of the cylinder wall of each air cylinder «»•«■> ly 236 Is rigidly connected to an angle member 244 to interconn'9ct the lower ends of each of the cylinder assemblies 236.

The end of each piston rod member 242 is rigidly connected to a hollow duct or snorkel member 246. 2ach snorkel me&ber 246 Includes an enlarged upper flange 248 having a passageway (uot shown) therein interconnected to a flexible hose vhich is selectively connected by suitable valves, to a vacuum or to e gas, as will be hereinafter described. A downwardly extending, elongate, substantially flattened hollow member 252 projects downwardly from the flange 248 and a passageway 254 is defined therein. The passageway 254 interconnects with the passageway in the flange 248.

Referring particularly to Figures 19 and 20, the passaqeway 254 terminates with an open bottom and substantially longitudinal upright slots 256 adjacent the open bottom. The air cylinder assembly 236 is constructed to permit at least the open bottom portions of the hollow members 252, including the slots 256, to project into the interior of the flexible container C so as to properly produce a vacuum therein and to add the desired gas thereto. 26 3 9 7 5 12 In order to properly align each snorkel member 246 within the flexible container C and between the gripping manifold'. li? and 134, a snorkel positioning assembly, generally 258 is provided. The positioning assembly 258 includes a rigid stop member 260 having an upwardly projecting flange 262, the stop 260 being rigidly secured to the upper face of the rear manifold 134. The positioning Assembly 258 further Includes an adjustable stop member 264 which is rigidly secured to the overhead frame o« and project* forwardly therefrom. A forwardly projecting flange 266 has an adjustable threaded stop 268 on a rear upright flange 270 and an adjustable threaded stop 272 on a front upright flange. The angle member 24 4, secured to the air cylinder assembly 236, has a support 2 74 mounted thereon. The support 274 has a rear downwardly projecting flange 276 and a front downwardly projecting flange 278 spaced from the re.ir flange 27f>. The rear flange 276 is positioned intermediate the threaded stops 268 and 272.

As best seen in Figure 5, when the rear mar.ifold 134 is in the full back position, the rear flange 276 on the support 274, secured to the air cylinder assembly 236, engages the roar stop 268. When the rear manifold 134 is moved to the full forvard position, as seen best in Figure 6, the flange 262 of the stop 260 moves away from engagement with the front flange 278, and the rear flange 276 on the support 274 engages the front threaded stop 272 so as to properly align each snorkel member 246 above the open upper end of the flexible container C and intermediate the manifolds 132 and 134. The air cylinder assexbly 236 moves forwardly, as the flange 262 on the rear manifold 134 engages the angle member 244 to push the vacuumizing assembly 56 3 0 7 0 2 to the forward position. The positioning assembly 258 assures that the snorkels 246, which pivot about the pivot point 2 38, are properly positioned at all times relative to the substantially horizontally movable 5 rear manifold, particularly for insertion into the flex ible container C.

Referring to Figures 5-7 the heat sealing assembly 58 includes a heating member comprising a tubular heating rod 282 positioned centrally therein. A heat seal bar 10 280, preferably of aluminium for heat transfer purposes, is movable from a rear position, as shown in Figure 5, within the hollow portion 184 of the rear manifold 134 to a full forward, heat sealing position as seen in Figure 17. The heat seal bar 280 is then in alignment with the 15 heat seal back up pad 148 positioned on the front manifold 132.

The heat seal bar 280 is movable relative to the rear manifold 134 by a pair of air cylinder) 284.

Each of the air cylinders 284 is rigidly mounted, as best 2Q seen in Figure 7, on the tear wall of the rear manifold 134 Preferably, a threaded connection 286 is provided therebetween. Movable piston rods 288 are riqidly interconnected at spaced positions to the heat seal bar 280.

Each of the cylinders 284 is positioned substantially 25 equidistantly on opposite sides of the central upright axis of the apparatus 50, as best seen in Figure 7. When air pressure is applied to the cylinders 286, the heat seal bar 280 selectively moves forwardly or rearwardly towards or away from the heat sealing position, as will be described hereinafter In greater detail, when in the full forward, - 28 - 3 9 7 5:: f>ea I lng position the rear sectioi. 128 through thf link and arm 224 eng.iges the m.«nlfold ! 1-1 to offset the fore.- of the air cylinder 284.

Apparatus 3<*"i omborilo<l in I'Ujurrr; ^2-JR is of j similar construction to th^t of the apparatus SO of Figures 1-20. The apparatus 300, like the Apparatus 50, Includes a package support frame, generally 302, a bag gripping section, generally 304, a vacuumizing and gas adding assembly, generally 306, and a heat ssaiing assembly, 10 generally 308. The apparatus 3CO includes several preferred structural and operative advantages to be hereinafter descr ibed.

As in the embodiment of Figures 1-20, the articles to be packaged, such as neat pieces M, are placed within a flexible container D. The flexible container D as shew. most clearly in Figures 24 and 25, is desirably constructed of the same heat sealable, gas impermeable material as the container C. The flexible container D is alsc substantJally planar as seen in Figure 24 and includes a sealed bottom 310 and sealed sides 312. The seal-.; 3 10 i. . ar.d 312 are preferably heat seals. An intermediate hcjI section 314, which may be a single relatively wide se.ii or two, separate but closely positioned seals, is positioned between the sides 312 to thereby define a pair of completely separate bag sections 316 having ocn upper ends. The bag n, preferably includes perforations 318 centrally of t!ic intermediate seal or seals 314 to define net only separate, inseparable bag sections. As will be hereinafter described, the bag D, having the sections 316 nay be advantageously . used, for example, by lower volume butcher shops or restaur ants, since the double section baq D permits one section ts - 29 - 397 52 be separated from the other section and the contents therein used while the other bag section is not disturbed and may be held for even longer periods of tine without affecting the controlled interior thereof and exposing ^ the interior to the atmosphere.

In describing the embodiment of Figures 22-29, reference will be made specifically to the storage of meat pieces M within the double section bag D, as best seen in Figures 25 and 29. The apparatus 300 operates in substant-10 lally the sane way as the apparatus SO, and the frame is of substantially the same construction and includes an upright support frame 320 to which an overhead frame assembly 322 is rigidly secured. Also, the bag support rame 302 is of substantially the same construction as the 15 conveyor assembly 84 of the embodiment 50.

The bag gripping section 304 includes a vertically reciprocal front manifold 324 and a forwardly and rearwardly movable rear manifold 326. The opposite ends of the front manifold 324 are each guldably supported for vertical 20 movement by bearing members (not shown) mounted at each end thereof and having the same construction as in the embodiment 50. As in the embodiment 50, the bearings are slidably guided by fixed upright rode (not shown) which are fixed to the overhead trame assembly S22. The desired vertical reciprocal 25 movement Is Imparted to the front manifold 324 by an air-cylinder assembly 332.

The air cylinder assembly 332 is pivotally secured at 334 to che overhead frame assembly 322, while the piston rod 336 thereof is rigidly secured at Its outer end to a 30 support bracket 338 which is fixedly secured to the central - 30 - 39752 portion of the front manifold 324. Passageways 340 are provided in the front manifold 324 and the passageways i-io corwiunIcatc with vacuum openings 342 in spaced upper an<! lower flexible sen ling pads 344 on the front manifold 324.

The rear manifold 32<> 1 ;s • iuld.il.ly nupi*)r*«'d for forward and rearward movement by i p.nir of swl.stunt 1 111 y upright pivot arms 348, pivotally secured at their upper ends to the overhead frame assembly 322. The lower ends of the pivot arms 348 are pivoted to a pair of brackets ISO, which are secured to the opposite ends of the rear manifold 326.

The motive force for moving the rear manifold 326 to the forward position is of somewhat different construction from the assembly used for the apparatus SO. An air cylinder 352 is positioned in a substantially verticjl position and is p /otaily jecured. above the rear manifold 326, at a pivot connection with the uprignt support ir*at J2u The piston rod 356 of the air cylinder 352 is pivotally secured to a toggle linkage 358. The toggle linkage 358 includes a front link 360 and a rear link 362. As seen in Flaure 23, two toggle linkages are ua*>d ond interconnected by a tie bar 363. Each rear lit»k 362 is pivctaliy secured at its rear end to a bracket 364 which is fixed to the upright frame 320 and at its forward end to the tie bar 363. The front link 360 is also pivotally secured to the tie bar 363 along the same axis as the rear link 362 while the forward end thereof is pivotally secured to a bracket 366 which is rigidly secured to the roar wall of 'h. rear manifold 326.

The rod 356 is rigidly secured to the central portion of the bar 363. As seen in Figure 22, when the air 39752 cylinder 352 is activated,the links 360 and 362 of «ach toggle mechanism 358 are moved into substantially axial alignment with each other to thereby positively engage the rear manifold 326 against the front manifold 324, 5 as in the embodiment 50. The rear manifold 326, as seen in Pigure 22, also includes upper and lower flexible sealing pads 368 which generally align with the vertically spaced sealing pads 344 on the front manifold 324. A hollow space 370 is defined in the rear manifold 326 10 between the spaced sealing pads 368.

The bag clamping mechanism, generally 372, for the embodiment 300 is somewhat different from the bag clamping mechanism used in the apparatus 50. Referring to Figures 27 and 28, a pair of bag clamping mechanisms 372 15 are laterally spaced &._ong the rear manifold 326 and operate to mechanically hold or clamp the upper edges of the bag 0 in a fixed position against the upper sealing pads 368 after the bag D has been manually positioned and before the bag D is under control of the vacuum provided in the 20 manifolds 324 and 326. Each bag clamping mechanism 372 ' includes an air cylinder assembly 374, which is pivotally secured, at its cylinder and, to a pivot member 376 which, in turn, is secured to a support bracket 378. The bracket 378 is rigidly secured to the rear wall of the rear mani-25 fold 326. A piston rod 380 of the air cylinder assembly 374 is pivotally secured at 382 to a clamping plate 384. The clamping plate 384 is pivotally secured tp a bracket 386 at a pivot connection 388, and the clu^inc plats 384 includes a downwardly extending portion which is movable 30 into position against the bag 0 to hold the upper edges of the bag D against the upper sealing pad 368 of the rear - 32 - manifolo 326. As with the embodiment 50, the l>ag clamps 372 act to hold the front bag panol In place, the rear bag panel being under the influence of the vacuum in the rear manifold 326.

The vacuumizing and gas addition assembly 30G of the apparatus 300 has significant advantages over that of the apparatus 50. The assembly 3G6 includes an upright air cylinder assembly, generally 390. As best seen in Figure 25 , the air cylinder assembly 390 is pivotally carried by a support 392 at a pivot connection 394. The support 392 is fixedly secured to the front of the overhead fraae assembly 322. The lower end of the air cylinder of assembly 390 is rigidly secured to a cross support 396 at a central portion thereof. In order to provide stability for the cross support 396, the opposite ends thereof, wi^ the air cylinder assembly 390 positioned substantially intermediate thereof, have a pair of upright support rods 3!S secured thereto. Tne. rods 398 are pivotally sp<•'ir'v! at their upper end* by pivot connections 400 to a pair of support brackets 402 which arc secured to tne overheat', frame 322. The pivot connections 400 are coaxial with : pivot connection 394 for the upper end of the ;iir cylinder issembly 390. The lower ends of the rods 398 are rigidly secured to the opposite ends of the cross support 39b. The rods 398, cross support 396, and the cylinder of the air cylinder assembly 390 generally define a pivoted frame.

The lower end of a piston rod 404 of the cylinder assembly 390 is rigidly secured to a cross plate 406 which Is positioned below and substantially parallel to the crops support 396. The cross plate 406, is reciprocal® betveer. 39752 raised and lowered positions.

Tho cross plate 406 has laterally spaced apertures therein for vertically slldably carrying a pair of snorkel assemblies, generally 408, at the opposite ends thereof. Each anorkel assembly 408 projects downwardly and includes a substantially flattened hollo*: p»«mber 410 having an upper flange 412 unitarily fixed thereon. Each flange 412 includes a passageway (not shown) therein which communicates with a central hollow passageway in the hollow member 410. The passageways in the flanges seaiably interconnect with a flexible hose (not shown) for selective communication with a vacuum source or pressurized gas.

In order to properly guide the snorkel assemblies 408 for upward and downward movement, the upper side of each flange 402 has a guide rod 416 fixed thereto and projecting upwardly therefrom in substantial alignment with the upright axis of the hollow member 410. Each guide rod 416 la slldably received by a bearing member 418 which is rigidly secured to the upper side of the cross plate 406, in a position intermediate the air cylinder assembly 390 and one of the support rods 398, in closer proximity to the rod 398. The upper end of each guide rod 416 Includes a stop or positioning flange 420 which is rigidly secured thereto.

As seen, the snorkel assemblies 408 are vertically and slldably carried by the cross plate 406 and are lnsertable into the flexible container 0. When the lower end of the hollow ataber 410 of the snorkel engages a meat piece M, that snorkel assembly 408 stops its downward descent. As Indicated best in Figure 29, even though one u ti 7 :»:: of the snorkel assetnblies 408 stc,?s, the other snorkel assembly 408 continues its downward movenient until it also engager a meat piece M stored within the container D. The arrangement is considered to have significant S advantages over the snorkel assembly used in the embodiment of apparatus SO for better assuring proper evacuation. In the snorkel assembly 408, the flexible bag D, during evacuation, is far less likely to collapse around and block the vacuum openings 422 provided in the hollow saefcers *iG 10 because these openings are relatively central of the containers. In this way. the desired vacuum in the flexible containers is more readily attainable to subatanf • -■'.1 ly remove all the air therefrom.

The apparatus 300 also includes a snorkel ^ positioning assembly, generally 424, for aligning the snorkel assemblies 408 relative to the rear manifold, at all times, particularly for insertion and withdrawal of the assemblies into the container D. The positioning assembly 424 provides a more positive snorkel positioning and is preferred over the positioning assembly 258 used s.n the embodiment 50. The positioning assembly 4 24 include-, a generally upright rod 426 which is rigidly mounted in n vertical position on the upper wall of the rear manifold 326. The upper end of the upright rod 426 is pivotally 25 secured to an arm 428 at a pivot connection 430. The arm 428 also pivotally connects with a linkage having a front link 432 and a rear link 434. The front link 432 and rear link 434 are positioned in a generally upwardly angled direction. The rear link 434 is civoted at its rear end JO to a bracket 436 secured to tne uprignt support fraaa 320. The front link 432 is pivoted at its front end to a support - 35 - 397 52 bracket 438 which la mounted on the underside of the cross support 396.

When the rear manifold 326 is moved to the full forward position, as seen In Figure 22, the upright red 426 also moves forwardly thereby pivoting the arm 428. The arm 428 pivots the links 432 and 434 Into axial alignment as seen in Figure 22, to thereby positively position the snorkel assemblies 408 at the required location above the opening between the manifold* 324 and 326, which initially hold the bag D open, for insertion and withdrawal of tha snorkel assemblies 408 into and from the bag 0.

The heat sealing assembly 308 for the apparatus 300 has substantially the sue structure *s the hast scaling assembly for the embodiment aO. Therefore, the heat sealing assembly 308 will not be described other than by reference to the embodiment 50.

The operation of both embodiments of our packaging apparatus, described above, that is, the apparatus 50, Illustrated in Figures 1-20 and the embodiment 300 illustrated in Figures 22-29, will be descriNed in conjunction with a description of our packaging aathod. For purposes of simplicity in description of the operation, reference will more generally be made to the apparatus 50 embodied in Figures 1-20. At times in this description, where there is a significant difference in operation as between the two embodiments, reference will be specifically made to the apparatus 300 embodied in Figures 22-29. Also, in describing the sequencing of the equipment, the various controls used will be described and reference will be made to the pneumatic flow diagram of Figure 21 and the electric diagrams of Figures 21A and 21B. Also, various limit switches, not previously described, will be located and discussed in describing the oper- - 36 - 30?^a dtlon and the packaging aat> A.

T/eferring first to Figures 1,2 and 5, the operator of the apparatus 50 first places a flexible container C (or double section flexible container 0) Into an open, 5 substantially rigid box B. Generally, at a separate station, the product to be packaged, such as neat pieces M, are placed, as seen In Figure 5, in the flexible container C or D. When the desired quantity of meat has been placed into the container the box B and its contents are transferred 10 to the packaging apparatus and placed on the conveyor assembly B4. The box is moved along in the direction of its longitudinal axis into a position where its opposite ends are substantially equally spaced Inwardly from the opposite ends of the front and rear manifolds 132 and 134. 15 The height of the assembly 84 will have been previously adjusted to the desired level.

When the box B is thus positioned, the open end of the flexible container C is in position to have the upper edges of the flexible container C held against the 20 vacuum openings 188, In the pads 186, in the frontwardly facing rear manifold 134. Preferably, the machine frjjne 60 includes a rear flap hold dewn bar 440 and side flap hold down bar 442 to assist in keeping the rear flaps of the box B out of the operator's way during operation of the 25 apparatus 50 or 300.

At this time, the operator grasps the panels of the container C or D along its seams and along its open upper end and then manually stretches the upper ends of the panels into a substantially wrinkle-free condition, in 30 which the upper edges of the sides are positioned in sub stantial alignment with each other. A vacuum is then beino - 37 - applied to the openings 188 through tht> pM«.r«wfy. 174 and through a hoae 190 which is selectively interconnected with vacuum from the vacuum pump 124. The vacuum pump 124 desirably operates at a vacuum of about 25-29" Hg and this vacuum acts to hold the rear panel of the bag C or D in a substantially wrinkle-free, condition against these vacuum openings 188. The operator has a clear view of the rear manifold 134 because the front aanifold is in a raised position and also the height of the rear manifold 134 is at substantially eye level.

Although the upper edges of the container C or D are desirably positioned in a substantially horizontal position, slight misalignment is not detrimental to the operation. In this regard, it is more important for the opposite panels of tha bag to be in such a position as to assure heat sealing thereof by the heat seal bar 280, which operation will be hereinafter described in greater detail. Three longitudinally spaced bag stops 183 axe preferably mounted on the rear manifold 134 to assist the operator in properly initially positioning the bag C.

Referring to Figure 12, the start of the automatic sequencing operation is shown. As shown, the heat sealing bar 280 is in the back or retracted position, the snorkels 246 are in the raised position, and the front manifold 132 is in the up position.

Once the operator has positioned the container C or D in the described manner against the rear manifold, little further skill is required from the operator, as will be described. This is considered an important feature because - 38 - 397^2 of significant reduction In human error. When the container C Is manually held against the pad openings 188 in the rear manifold 134, referring to Flqure 21, vacuum switch -'43 senses an Increase in t:>u vacuum In 5 the vacuum lines because the openings 188 are closed to the atmosphere. When the switch 443 senses that a vacuum of about 15-18" Hg is reached, the clamp solenoid valve 444 is energized, as shown in Figure 21, to permit pressurized air, at normal plant air prssvur*, to pass to both of the 10 clamp air cylinders 200 of ths embodiment 50, or in the embodiment 300, to the air cylinder assemblies 374. (In this description, the coll of each solenoid valve and the valve itself will be given the setae reference number, for purposes of simplicity.). When this occurs, the 15 clamping mechanisms 198 (or 372) are activated to mechanically clamp both panels and particularly the front panel of the container C or D against the rear manifold, as best seen in Figures 8 and 9,for the embodiment 50 and in Figures 27 and 28, for the embodiment 300. After the clamps have 20 been activated, in addition to their mechanical clamping function, their activation is a signal that the container is properly positioned and sequencing may commence. Thereafter, the operator moves his hands out of the way of the manifolds and the manually operated switch 446, as seen in Figures 25 1 and 21A, is activated. From this time on, the entire sequencing operation for the equipment is completely automatic and little further manual skill is required. One of the few instances where "•ssistance of the operator is called for is when the container C appears to have air pockets, and may 30 require the operator to manually move the panels of the container to substantially eliminate the air pockets; even this - 39 - •A 9 7 5 Ji is generally found only In the embodiment 50, and not In the embodlmont 300.

Activation of the manual switch 446 performs several functions. First, the closing of switch 446 activates the front manifold solenoid valve 440, which, in turn, energizes the drive cylinder assembly 1S8, to permit pressurized air to enter the cylinder assembly 158 and cause the front manifold 132 to nov« downwardly, as Indicated in Figure 12. The manual switch 446 further activates a relay 449, seen in Figure 21A, the purpose of which will be hereinafter described.

As seen best in Figure 10, a limit switch 4SO, mounted on the overhead frame 64, is positioned to be activated by a tripper 451 which is movably mounted on the manifold 132 When this occurs, the front manlfol<J 132 is in the full down position and is generally horizontally aligned with the rear manifold 134 as seen In Figure 13. The normally closed switch 450 is opened when the front manifold 132 is down, to thereby de-activate the elamps to move tnem out of the way when the rear manifold 134 is moved towards the front manifold 132.

Referring to Figure 14, while the snorkels 246 are still in the up position, the rear manifold 134 is moved forwardly, like the deactivation of the clamps, when the limit switch 450 has been activated. The limit switch 450 activates a rear manifold solenoid valve 452 through tine delay switch 452A, as seen in Figure 21A, which nermits pressurized air to be applied to the drive cylinder 214 to move the rear manifold 134 forwardly, as shown. As seen in Figure 21A, when the llrait switch 450 is closed, circuits - 40 - 3 9 7 r< controlled by the time delay relay 454 are affected.

First, a switch 455 Is activcted to energize the vacuum solenoid <56 to apply vacuum to the front manifold.

When the misaligned pad openings 144 and 188 in the front and rear manifolds 132 and 134 engage opposite sides of the container C by means of vacuum in both manifolds, the front section of the container C is under control of the front manifold 132 while the rear section or panel of the container C is under control of the rear manifold 134.

When the delay switch 452A of the relay 45* times oat, the v«1y« 452 close* and the cylinder 214 reverses movement to move the rear manifold 134 rearwardly, as lndlcat^l in Figure 15, while the container is opened because e.ich baq panel Is under the control of the vacuumlzed f»-ont or rear manifold 132 or 134. When the rear manifold 134 reaches the full back position, a limit switch 457 is contacted. The snorkel solenoid valve 4 58 , as seen in Figures 21 and 21A is energized to cause pressurized air to be applied t: the srorkel cylinder assemblies 236 for moving the snorkel? 246 downwardly into the container C, which is opened below the snorkels.

The snorkel positioning assembly 258 (or 424) rsain-tains the snorkels in a pre-deterinined position relative to the rear manifold. The assembly 258 (or 424) is mounted on the rear manifold and pivots the snorkel assembly in response to forward and reverse movement of the rear manifold. This positioning is particularly important in positioning the bottom of the snorkels 246 in aliyned relationship with the open container. The snorkels are positioned substantially intermediate the manifolds 132 and 134 and thereby - 41 - 39752 centrally of the open portion of the container.

The snorkels 246 enter the open upper end of the container C, as generally shown in Figure 15, *hile the rear manifold 134 is spaced back from the front manifold 132. In the embodiment 50, of Figures 1-20, the bottoms of the snorkels 246 are positioned to a predetermined level in the container C, but below the manifolds 132 and 134-The open portions in the bottoms of the snorkels must ba completely within the container C. The vacuum openings of the snorkels sometimes are closed by the panels of the container and the operator may have to manually pull thw panels from the vacuum openings in order to obtain a proper vacuum level.

In the embodiment of Figures 22-29, and as seen best in Figure 29, the snorkels 'float" or move to a level where the bottoms of the snorkels 408 actually engage the surfaces of the meat pieces M. The cylinder 390 moves the cross plate 406 downwardly and ♦•he cross plate 406 carries the snorkel assemblies 408 downwardly. The snor'iwl flanges 412 rest on the cross plate 406. When the bottom of the hollow member 410 strikes the meat M within the container C, further downward movement of that snorkel la stopped even though the cross plate 406 continues its downward descent, together with the other snorkel 403. The other snorkel continues until it also strikes a meat piece. Thus, the hollow members 410 of the snorkel assemblies 408 can extend downwardly into the flexible container to different levels closer to the meat than in the embodiment of Figures 1 to 20, thereby providing better assurance that the desired vacuum level will be reached without manipulation of the container. - 42 - 3 8 7 5 y During the downward descent of the snorkel assemblies, the spacing of the snorkels from .he front and rear manifolds is determined, in the apparatus SO, by the snorkel positioning assembly 258 and, in the embodiment 300, by the positioning assembly 424.

Referring to Figure 11, a trip arm 461 on the snorkel 246 strikes the arm 462 on a limit switch 464, mounted on top of tha rear manifold 134, for signaling whan the anorkals 246 are in the down position. When the switch 464 is so energized, it opens a circuit to de-energize the relay 454 and closes a circuit to energize the coil of a solenoid 466 and open the interior of the snorkels 246 to vacuum, as seen in Figures 21 and 21A.

When the relay 454 has been de-energized, tho normally closed delay switch 452A closes and the solenoid valve 452 is energized again, to move the rear manifold forwardly.

When the rear manifold moves forward the limit switch 457 changes circuits, as seen in Figure 21A, to de-energize solenoid 456 and energize solenoid 460, and thereby cut vacuum to both manifolds 132 and 134. As there is only a fraction of a second involved, residual vacuum holds the container in place until the manifolds are clamped together. Because the pads on the manifolds are flexible, the interior of the bag C is sealed from the atmosphere. The manifolds are in sealing engagement with the bag panels which form around the hollow, passage defining portions of the snorkels. When the container C is effectively sealed from the atmosphere, air is drawn from the container C through the snorkels 246 to remove substantially all the air therefrom and create a vacuum therein. A suitable vacuum level is considered to be in the range of about 25-29" Hg. When the vacuum «witch 468 as seen ir. Figures 21 and 21A, detects a vacuum in the desired range cf about 25-29" Hg, vacuum switch 468 closew. The switch 470 having been closed previously by the relay 449, and the closed vacuum switch 468 cause the colls of the nitrogen solenoid valve 47 2 and of the carbon dioxide solenoid valve 474 to be energized. The awitch 470 also energizes a relay 476 which, in turn, opens the switch 478 and cuts vacuum to the snorkels. With the vacuum cut, pre-deterrained quanti ciaaof carbon dioxide and nitrogen in the accumulators 118 and 120 are charged into the evacuated container C or D.

The amount of carbon dioxide and nitrogen added to the container may vary over a wide range, depending on the material and amount thereof being packaged, and tha size of the container and its closed volume. In practice,ear-h accumulators it capable of receiving a measured volume of gas at a pre-selected pressure. Simply by changing the pretsure level, the amount of gas which is added to the container can vary. In one example, 414 cubic inches of nitrogen and 414 cubic inches of carbon dioxide are added to the bag C per 75 pounds of beef) this provides a 50% concentration of carbon dioxide in the bag. Depending on the various parameters, the added gas can vary over a wide range, such as 2-10 cubic inches per pound of meat product for each of the gases. Although the nitrogen is not considered to have any significant preserving effect on the r._Bat, it is believed that the nitrogen functions to reduce the concentration of the carbon dioxide. If the concentration of carbon dioxide is at too high a level, the meat, such as beef, begins to turn gray or darken, an undesirable condition. Thus, 39702 •he nitrogen, basically an Inert gas, serves tho Important function of providing a concentration of carl.on dioxide at such a level that the meat does not darken from exposure to cf.rbon dioxide over extended periods of 5 time. It is considered an Important feature of the nsthod to maintain th« natural colour of the fresh red meat, even over extended periods of tine, as for thirty to forty-five days.

Carbon dioxide is Important In reducing bacteria iO growth. Bacteria is generally always present on the surface of the meat. In order to reduce the growth of aerobic bacteria, air is flrsc removed, and then, in order to inhibit the growth of the aerobic bai-terl.i, carbon dtoxlde is added. Carbon dioxide also has the Important effect 15 of reducing or inhibiting the growth of anaerobic bacteria. Although vacuumizing is important for greatly reducing the amount of enclosed air, residual air is generally present in the container and without the carbon dioxide, aerobic bacteria, as w>ill as anaerobic bacteria, can grow over extended periods of time. Such growth can be detrimental and cause the bacteria level to Increase beyond accepts 1«-limits when the apparatus SO (or 300) is used In the packaging of food products, as fresh meat. For these reasons, carbon dioxide, at appropriate concentrations, Is important.

It is also important in the aachcxi that, after vacuumizing, th-? pressure In the flexible container Is at substantially atmospheric pressure, or slightly below. In the case of a vacuumlzed container C, the container Is normally tight against the meat. Particularly in large bulk packaging of products, as 50-100 pound packages, a condition - 45 - 39752 in which the container C is taut makes the container susceptible to breakage. Also, if the gas pressure within the container C or D exceeds atmospheric pressure, the container can actually expand and become stretched. 5 A container that is expanded from pressure in excess of atmospheric is also considered undesirable and susceptible to breakage during handling. Thua, the container C should be J . a substantially relaxed condition after complete p«ckaging so aa to b« leas susceptible to breakage, 10 as opposed to a flexible container which is vacuum lied or which is expanded frcn pressure therein.

The vacuum switch 468, when closed, energizes the time delay relay 476, as previously described. The relay 476 includes a delay switch 480 which opens after a time 15 delay sufficient to assure that the desired gases have been added to the container. Opening switch 480 de-energizes the coil of the colenold 458, to cause the snorkels 246 to move upwardly a.~.d out of the container C. A delay switch 482 of the relay 476 also opens to de-energize 20 solenoids 472 and 474 and close off the accumulators to the snorkels and open them to be charged with the desired volume of gases from the carbon dioxide and nitrogen tanks. The pressure regulators 484 control the pressure and thereby volume of gases added to the respective accumulators. 25 As seen in Figure 17, the manifolds 132 and 134 remain in sealing relationship with the sides of the container C so that during the withdrawal of the snorkels 246, the sealing of the open upper end of the container C is substantially unaffected because of the double, rear 30 flexible sealing pads and the gaseous atmosphere in the container remains substantially the same. Also, since the - 46 - 'J 9 7 i> ^ gas In tha container C or 0 Is at substantially the same pressure as the atmosphere, there is no tendency either for air to enter,or for the gas to leave the container C.

When the snorkels 246 have reached their full up position, limit switches 486 are held in a closed position. A delay relay 488 it* energized by the closing of the Halt switches 486. Also, this energizes the heat seal bar solenoid valve 492 to cause pressurized air to operate the air cylinders 284 to wove the heat bar 280 forwardly to the heat sealing position. The bar 280 heats thy adjacent panels to provide the heat seal 494 on the container C or D. The relay 488 alsc includes a delay switch 496 which is timed to open when the desired amount of heating has occurred. The opening of this switch de-energizes the solenoid 492 and the heat seal bar 280 retracts.

At this time, the entire vacuumizing gas adding and ,ieat sealing cycle having a variable duration, such as about 15-2 5 seconds, Is complete and the front manifold 132 returns to the up or start position. When the front manifold 132 moves upwardly, the limit switch 450 opens ar.d the rear manifold 134 moves rearwardly because the solenoid valve 452 is de-energized. The container C and box B are moved away from the apparatus for sealing of the flaps and the apparatus is ready for a new cycle.

In the foregoing description, it Is to be understood that only the more important aspects of the sequencing have been described, and there may be other sequencing operations occurring which are not herein described, but which are schematically shown.

Freferably, a water supply 495 may be provided for flushing the various lines with water, as seen in Figure 21. When the switch 496s ia manually closed, the solenoid valve 498 Is energizod causing rinse water to clean the lines.

Referring to Figure 21B, the electrical schematic for the vacuum pump motor SOO is shown. The fusing and grounding thereof is shown. The lines 502 and 504 are the some as lines 502 and 504 in the electrical schematic of Figure 21A.

The thus packaged meat may be stored at refrigerating temperatures as about 35-50°F. for periods of time as much as forty-five days without adversely affecting the fresh red colour of the fresh meat and without unduly Increasing the bacteria count, whether aerobic or anaerobic bacteria are involved, beyond acceptable levels for human consumption.

One Important result of the «stbo4 is that the packaged meat product permits natural tenderisation to occur without mold growth. As an example, a beef rib, packaged as above, may Le stored at a temperature of about 41°F. for fifteen to thirty days, and the meat la tender and tasty. The aging or tenderization time can be significantly decreased by storing the meat at a higher temperature, as about 50-59°F. for three to five days, while retaining the red colour of the meat emd maintaining a low bacteria count. Even after opening the package, the shelf life of the meat in a normal atmosphere and at 36°F is approximately ten days. - 48 -

Claims (4)

1. CLAlMSi- X. Apparatus for packaging one or morn articles In a flexible container hjvlnq an open er.d, which apparatus comprises meana for supporting the container with said one or nora articles therein; means for releasably gripping the container on opposite sides thereof at the open end, said means being movable between open and closed positions to open and close said open end duct neins movable into and out of said open end to coaoiunicatc with the interior r.f the container; and wherein the gripping means carrtcs means for temporarily seallngly closing said open end with the duct means present in said open end and during and after removal of the duct means therefrom, the duct means being conrected to means for creating a predetermlnable atmosphere within the container by the passage of gas along the duct means while said open end Is temporarily closed and the apparatus further Including means for heat-sealing said open end to close the container.
2. 2. Apparatus according to Claim * wherein the creating means comprises means for selectively vacuumizing the container and feeding a gas thereto through the duct means, which vacuumizing and feeding means comprises a vacuum source and a gas source, the apparatus including means for sequencing the apparatus to first vacuunize the container and thereafter add gas thereto.
3. 3. Apparatus according to Claim 1 or claim 2 wherein tha supporting means is positioned below the gripping - 49 - 397 34 means and below the duct means. 4. Apparatus according to C^alra 3 wherein the supporting means is vertically adjustable so that the vertical position of the container may be adjusted 5 relative to the duct means. 5. Apparatus according to any preceding Claim wherein the heat-sealing means includes an elongate heat sealing bar and a spaced heat-seal backup mamber. 6. Apparatus according to any preceding Claim wherein 10 the gripping means ccaprlsas a pair of substantially horizontally positioned, elongate members for control1ably gripping opposite sides of the open end while the sides of the container are, adjacent-, said end, in a substantially flattened, wrinkle-free condition. 15 7. Apparatus according to Claim 6 wherein the elongate meicbers comprise spaced vacuum manifolds having a plurality of vacuum openings therein, and means are provided for supplying vacuum to the openings for holding the opposite sides of the open end and maintaining th>- container in the 20 open condition at selected times. 8. Apparatus according to Claim 7 wherein the vacuum openings in one manifold are offset from those of the other manifold when the manifolds are aligned. 9. Apparatus according to any of Claims 6 to 8 wherein 25 the temporary sealing means are mounted on the elongate members and Include spaced upper and lower flexible seal- - 50 - 3 9 7 C, ing members capable of sealing around the duct, means whan the elcmgace ucsfeara jcu juxtaposed In the closed posi tion. 10. Apparatus according to any of Claims 6 to 9 5 wherein the haat-sealing means la supported on the elongate members. 11. Apparatus according to any preceding Claim wherein the duct means comprises a plurality of conduits, the temporary sealing »ean* being adapted to engjge the Jf| conduits to close the interior of the cont.iirpr to the atmosphere when '.he gripping means L* in • lie closed position. 12. Apparatus according to Claim 11 wherein each conduit is movable to a different level in the container. ^ 13. Apparatus according to any preceding Claim in cluding means for moving the duct means in and out of said container and means for positioning the duct means relative to the gripping means prior to movement thereof into the container. 14. Apparatus according to Claim 13 including means permitting the continued movement of the moving means while the movement of the duct means into said container is stopped. 15. Apparatus according to Claim 13 or Claim 14 *5 wherein the positioning means is at least partly mounted on the releasable gripping means. - 51 - 3 9 7 S 2 16. Apparatus according to any of Claims 1.1 to IS, wherein the moving means Includes an air piston and cylinder mechanism. 17. Apparatus according to any preceding Claim including 5 means for clamping both sides of the /lexible container together at Its open end before activation of the releasable gripping means. 18. Apparatus according to Claim 17 wherein said clamping means are mounted on only one of a pair of 10 members comprising the releasable gripping means. 19. Apparatus according to Claim 2 or any Claim appendant thereto including control means for controlling the operation of the apparatus, which control means Includes manually operated means and automatic sequencing means, the manually operated means being operable to commence the operation of the automatic sequencing means, and the automatic sequencing means thereafter being operable to actuate the gripping means , to control the movement of the duct means, activate the means for vacuumizing and feeding a gas to the container and actuate the heat-sealing means without further manual operation. 20. Apparatus according to Claim 19 wherein the releasable gripping meana comprises a pair of vacuum manifolds, wherein the control means comprises a vacuun switch oper- 25 atlve when the vacuum in one of the manifolds is at a preselected level, the apparatus including means responsive 15 20 - 52 - 39752 to the vacuum switch for temporarily clamping both sides of the container at its open end, and wherein the manual means comprises a manual switch for commencing the operation of the automatic sequencing means. 21. Appaittua according to Claim 19 or Claim 20 wherein the gripping means Includes an elongate front vacuum manifold elongate rear vacuum aanifold, the front manifold being movable from a raised position to a lowered position as said manual means commences the operation of the sec/uencing means, and the control means includes limit switch means to detect when the front manifold is in the lowerposition. 22. Apparatus according to Claim 21 including drive means for moving the rear manifold forwardly from a rearward position towards the front manifold, the drive means beini operable in response to the limit switch. 23. Apparatus according to Claim 22 including a time switch actuated by the limit switch, having a delay time during which time the rear manifold moves to secure a container against the front manifold, a vacuum being applied to each manifold to hold a respective side of the container, the switch then being operative to actuate the drive means to return the rear manifold to its rearward position so that the container is held with its end open. 24. Apparatus according to Claim 23 Including a switch for indicating that the rear manifold has returned to its - 53 - rearward position, and raaans for moving said duct means in response thereto. 25. Apparatus according to Claim 24 wherein said sequencing means includes a vacuum switch responsive to a preselected vacuum level in »ald container, for shutting off the vacuumlzlftg means and activating the means for adding a gas to a said container. 26. Apparatus according to Claim 25 including a tine switch for halting the delivery of gas to said container after a predetermined delay tine, drive means responsive to said time switch for withdrawing the duct means out of the container while said container ronalns in the temporarily sealed condition and means for actuating the heat-sealing means after said duct means is withdrawn. 27. Apparatus according to Claim 26 including means for returning the rear manifold to the rearward position, the front manifold to the raised position and for deactuat-ing the heat-sealing means after the heat-sealing operation to complete the cycle of operation. 28. Apparatus for packaging one or more articles substantially as described herein with reference to the accompanying drawings. 29. A method of packaging one or more articles in a flexible container having an open end ccoprising supporting the container with said one or more articles therein; 54 - 39Tb:: gripping the container on opposite sides thereof .u tin? open end and separating said sides from ..-ach other to hold said end open; moving duct m<ans into the container through said open end and bringing said opposite sides together to sealingly ciose the open end around the duct neans; applying a vacuus to the duct means to evacuate the container and subsequently feeding a gas to the container through the duct Beans in an amount sufficient to inhibit deterioration of tha article or articles, withdrawing the duct means from the container while maintaining said open end sealingly closed frcm the surroundings and thereafter heat-seallng said open end to close the container. 30. A method according to Claim 29 wherein the gas fed to the container contains carbon dioxide. 31. A method according to Claim 30 wherein the container is vacuumlzed to 25-29" Hg er.d wherein the carbon dioxide fed to the container is mixed with an inert gas. 32. A method according to Claim 31 wherein the inert gas is nitrogen. 33. A method according to Claim 31 or Claim 32 wherein the concentration of carbon dioxide in the mixture is substantially 50% by volume. 34. A method according to any of Claims 30 to 33 wherein the article or articles comprise one or more primal cuts of red beef. - 55 - 39752 35. A method of preparing fresh red beof for consumption comprising a method according to Claim 34 end Including the step of holding the beef In said container at refrigerating temperatures for at least fifteen days. 36. A method according to Claim 35 wherein the meat Is held at a temperature of 35-50°F for a period of 15-30 days. 37. A method according to Claim 35 oz Claim 36 wherein the beef Is held until natural enzymes have produced a tenderized beef product. 38. A method according to any of Claims 29 to 37 Including the step of Initially placinc the container into a substantially rigid outer case. 39. A method according to any of Claims 29 to 38 including the step of stretching the open ond of the container into a substantially wrinkle-free condition before the gripping step, holding the open end of the container in said substantially wrinkle-free condition by the application of vacuum on the outer surfaces thereof, and wherein the heat-seallng step is accomplished along the open end of the container while the open end is in the substantially wrinkle-free condition. 40. A method of packaging one or more articles in a flexible container substantially as described herein with reference to the accompanying drawings - 56 - :»0 7 it :i 41. The product of a method according to any of Claims 2') to 40. 42. A product according to Claim 4 1 wherein thr flexible* container comprises two distinct and separable 5 compartments.
4. 4 . A flexible container containing one or more articles substantially as described herein with reference to the accompanying drawings. F.R.KELLY A CO. AGENTS FOR THE APPLICANTS. - 57 -