Packaging Machine

Abstract

A form-fill-seal packaging machine having a vertical mandrel around which a web of packaging material is formed into tubing, the tubing being fed downward off the lower end of the mandrel and formed, below the lower end of the mandrel, with transverse seals constituting package end seals at package length intervals. Below the lower end of the mandrel is a nozzle for delivery of the product to be packaged into the lower end of the tubing. The nozzle is formed with means for spreading the tubing flat, this spreading means being provided with a passage for communication between the space in the mandrel thereabove and the tubing therebelow, and presser plates are provided for pressing the opposed walls of the tubing against the spreading means.

Description

BACKGROUND OF THE INVENTION

This invention relates to packaging machines, and more particularly to a vertical form-fill-seal packaging machine.

The invention is particularly concerned with a vertical form-fill-seal packaging machine, particularly for packaging a liquid such as milk, of the general class shown in the Gausman et al. U.S. Pat. No. 3,050,916 in which a web of packaging material is formed into tubing around a vertical mandrel, the tubing being fed downward off the lower end of the mandrel, and formed with transverse seals spaced at package length intervals constituting package end seals, with delivery of metered quantities of the product (e.g., liquid milk) with which the packages are to be filled in the intervals between formation of successive end seals. One of the problems encountered with such machines is that of providing a so-called "soft" package, meaning one which is partially deflated (as opposed to one which is wholly distended by its contents and by air trapped in the package), without interfering with the accuracy of filling of the packages. Another problem encountered with such machines is that of excluding ambient air from the package as is desirable in the packaging of milk or any other product as to which a sterile environment is necessary or desirable.

SUMMARY OF THE INVENTION

Accordingly, among the several objects of this invention may be noted the provision of a vertical form-fill-seal packaging machine of the class described above, particularly for packaging liquid milk in plastic film such as polyethylene, adapted to form soft packages with accurate metering of the product into each package; and the provision of such a machine adapted to exclude outside air from the packages.

In general, a machine constructed in accordance with the invention comprises a generally vertical mandrel around which a web of packaging material is formed into tubing, the tubing being fed downward off the lower end of the mandrel and formed, below the lower end of the mandrel, with transverse seals constituting package end seals at package length intervals, these end seals being formed in a generally vertical plane. Means is provided for delivering the product which is to be packaged to the lower end of the tubing below the lower end of the mandrel. Further, means is provided below the lower end of the mandrel for effecting transition of the cross section of the tubing from the cross section of the mandrel to a flattened cross section generally in the stated vertical plane of the end seals. Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation of a form-fill-seal packaging machine embodying this invention;

FIG. 2 is a side elevation of FIG. 1 with parts broken away;

FIG. 3 is side elevation of the filling system of the machine, on a larger scale than FIG. 1, with parts broken away and shown in section;

FIG. 4 is an enlargement of the lower part of FIG. 3 with parts shown in section;

FIG. 5 is a front elevation of FIG. 4;

FIG. 6 is a horizontal section on line 6--6 of FIG. 4;

FIG. 7 is a side elevation of the parts shown in FIG. 4;

FIG. 8 is a horizontal section on line 8--8 of FIG. 4; and

FIG. 9 is a fragmentary view of the lower part of a nozzle of the machine, partly broken away and shown in section.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first more particularly to FIGS. 1 and 2 of the drawings, there is indicated at 1 a vertical form-fill-seal packaging machine equipped with a liquid dispenser or filler 3 particularly for packaging milk, it being understood, of course, that the invention is adapted for packaging other liquid products. Generally, the packaging machine 1 comprises a base 5 and a frame 7 extending up from the base. At 9 is indicated a tubular cylindrical mandrel which is mounted in vertical position at the front of the frame 7. A supply roll R of a web W of suitable packaging material is mounted at 11 in the frame. The web W is fed from the roll R around guide rollers 12 and 13 to the upper end of the mandrel 9, being formed into tubing T around the mandrel as will be readily understood by those skilled in the art, the tubing being completed by formation thereof with a longitudinal seam such as indicated at L in FIG. 1 by means of a longitudinal sealer 14 located in front of the mandrel. At 15 is indicated a carriage adapted to reciprocate vertically upward and downward toward and away from the lower end of the mandrel. This carries end seal bars indicated at 17 adapted, on each downward stroke of the carriage, to close on the tubing T below the lower end of the mandrel and to form a transverse seal (an end seal) across the tubing while pulling down one package length off the lower end of the mandrel. The bars 17 then open, and the carriage then moves upward for the next cycle, the tubing dwelling in place during the upward movement of the carriage.

The dispenser of filler 3 comprises a product supply tube 19 which extends vertically downward within the mandrel from a product supply reservoir 21 to the lower end of the mandrel (which is open). The product supply reservoir 21 is shown as being in the form of an inverted cone having its upper end supported by an arm 23 on a post 27 extending up from the frame 7, the reservoir being mounted in position directly above the mandrel 9 and coaxial therewith. The tube 19 extends down from the apex of the inverted conical reservoir, which, in the operation of the machine, will constantly contain a supply of liquid, e.g., milk, so as to maintain a head of the liquid in the tube 19. At the lower end of the tube 19 is a hollow cylindrical valve body or bell 29 of larger diameter than the tube 19, having an inwardly directed flange 30 (see FIG. 4) at its upper end surrounding and secured in sealed relation to the lower end of the tube 19. Body 29 forms, in effect, an enlargement of the tube 19 at its lower end. Removably fitted in the lower end of body 29 is a nozzle 31. This nozzle has a cylindric upper section 33 which has a snug fit in the body 29, a cylindric intermediate section 35 extending down from section 33 coaxial therewith and of smaller diameter than section 33, and a lower section 37 of special form in accordance with this invention as will be subsequently described. The upper section 33 has an annular peripheral groove 39 (see FIGS. 4 and 5) receiving an O-ring 41 of suitable rubber or the like for forming a seal between the nozzle and the body. The upper section 33 also has a lower portion of reduced diameter as indicated at 43, providing a downwardly facing shoulder 45. A ring 47 of rectangular cross section of stainless steel material suitably seated in an annular internal groove 49 in body 29 adjacent its lower end surrounds portion 43 and underlies the shoulder 45. This ring 47 is adapted to allow the nozzle readily to be removed from the body 29.

The lower section 37 of the nozzle 31 is formed to constitute a spreader for the tubing T, and has a central portion 51 and two spreader wings 53 flaring outward and downward from the central portion at diametrically opposite sides thereof (see FIG. 9). The space between the two wings is indicated at 55. The central portion 51 and the wings 53 are formed of generally wedge-shaped cross section with flat front and back faces 57 which are inclined toward one another in downward direction (see FIGS. 4 and 7). The wings 53 have vertical outer edges 58, with rounded approaches 59 to these edges, and narrow horizontal lower edges 60.

The nozzle 31 has a relatively large-diameter vertical passage 61 extending down from its upper end through its upper section 33 and its intermediate section 35 and part way down into the central portion 51 of its lower section 37, with a smaller-diameter continuation 63 of this passage down through the latter to its lower end. This provides an upwardly facing shoulder 65 at the lower end of passage 61 constituting an annular valve seat engageable by a valve 67 movable up and down in passage 61. This valve 67 comprises a disk 69 at the lower end of a stem 71 provided on the bottom thereof with a ring 73 of a suitable resilient yieldable material, such as a suitable rubber, engageable with the annular valve seat 65. The valve stem 71 has its upper end secured in the lower end of a rod 75 which extends down through the supply tube 19, and carries a triangular collar 77 which serves to center the valve in the passage 61, the apices of this triangular collar being in sliding engagement with the internal surface of the nozzle 31 in passage 61.

The rod 75 extends up from the valve 67 entirely through the tube 19 and the reservoir 21 and is actuated by an air cylinder 79 mounted above the reservoir on the upper arm 23. In the operation of the machine, a package length of tubing T is pulled downward off the mandrel 9 on each downstroke of carriage 15 with end sealers 17 closed on the tubing. The end sealers form the package end seals when they close on the tubing at the upper end of the carriage stroke, and during each interval between formation of successive end seals the air cylinder 79 is actuated to pull up the rod 75 to open the valve 67. The liquid, e.g., milk, thereupon flows down through the passage 61 and 73 in the nozzle under the head of liquid in the tube 19 and reservoir 21, and the valve 67 is maintained open for a time interval such as to provide for metering out through the nozzle 31 of the quantity of milk desired to fill the package being formed. At the end of the filling time interval, the air cylinder 79 is actuated to drive the rod 75 downward to close the valve 67 by seating of the ring 73 against the valve seat 65 to cut off the flow of milk. The carriage 15 rises with the end sealers 17 open after each downstroke and, after completion of the filling operation, the end sealers 17 are closed and the carriage 15 stroked downward to repeat the cycle.

As shown best in FIG. 3 the mandrel 9 extends down from an upper part 7a of frame 7 having a head 81 at its upper end secured to the bottom of this part of the frame. The product supply tube 19 extends down through the heat 81, the latter closing off the upper end of the mandrel around the supply tube (which extends down from the lower end of the reservoir). At 85 is indicated a line for supplying a gas under pressure to the upper end of the mandrel 9, i.e., to the space 87 in the mandrel around the product supply tube 19. This gas is delivered to line 85 from a main supply line 89 via a pressure gauge 91 and a filter 93. It may be sterilized air or a sterilizing gas such as ethylene oxide. At 95 (see FIGS. 4 and 8) is indicated a four-arm spider arrangement for centering the product supply tube 19 in the mandrel, the arms being designated 96.

The tubing T passes off the lower end of the mandrel 9 (which as herein illustrated is of circular cross section) and thence downwardly in surrounding relation to the bell 29 and the nozzle 31 with its wings 53. The latter constitutes means for spreading the tubing T and effecting transition of its cross section from the circular cross section at the lower end of the mandrel 9 to the flattened cross section indicated at FT in FIGS. 4 and 5 corresponding to the peripheral outline established by the lower edges 60 of the wings 53. Means 97 is provided for pressing the opposed walls of the tubing T against the flat faces 57 of the lower section 37 of the nozzle 31 including its central portion 51 and the two spreader wings 53. As shown best in FIGS. 4-7, this pressing means comprises a pair of presser plates each designated 99 which, as will appear, are spring-biased to press the front and back walls of the flattened tubing T against the front and back faces 57 of the lower section 37 of the nozzle.

Means for mounting the presser plates 99 on the machine 1 is shown to comprise an elongate bracket 101 mounted in vertical position extending downward from a part 7b of the frame 7 of the machine. This part 7b of the frame is at the back of the mandrel 9 as viewed in FIG. 1 from the front of the machine. A rock shaft 103 extends horizontally across the front lower end portion of the bracket 101, being journalled in a pair of spaced bearings 105 on the front of the bracket at its lower end. The shaft 103 extends outward on both sides of the bracket 101 and has a pair of split clamps 107 clamped thereon at its ends. A pair of arms 109 extends radially with respect to the shaft 103 from these clamps forward on opposite sides of the nozzle 31. Bars 111 extend down from arms 109 adjacent their front ends. Bolts 113 extend through the bars 111 adjacent their lower ends parallel to arms 109 and carry eyes 115 of pivot pins 117 extending into holes 119 in the ends of the presser plates 99. A bell crank 121 secured on shaft 103 between the bearings 105 has an upwardly extending arm 123 and a rearwardly extending arm 125. A coil compression spring 127 reacts from a spring seat 129 at the lower end of a screw 131 threaded in a lug 133 on the back of the bracket 101 against the arm 125 of the bell crank to bias shaft 103 to rotate in counterclockwise direction as viewed in FIGS. 3, 4 and 7, and thus biases arms 109 to swing upward and pull the presser plates 99 upward so that they press the opposed walls of the tubing T against the flat faces 57 of the lower section 37 of the nozzle 31 including its central portion 51 and wings 53. Upward movement of arms 109 (and plates 99) is limited by engagement of arm 123 of the bell crank 121 with a screw 135 threaded in bracket 101.

One of the spreader wings 53 of the nozzle 31 is provided with a passage 137 therethrough (see particularly FIG. 9) providing for communication between the space in the tubing T above the wings and the space 55 below and between the wings. A partial plug 139 constituted by a headed pin with a flat at 141 is inserted in the passage to provide a restricted orifice at 143 for said communication. This plug may be removed and replaced with plugs with different flats at 141 for varying the size of the orifice. Thus it constitutes a variable orifice means in the passage 137.

In the operation of the machine 1 as above described, the web W is formed into the tubing T around the mandrel 9 with the longitudinal seam 5 of the tubing at the front of the mandrel, and the tubing is fed downward off the lower mandrel 9 around the lower section 37 of the nozzle constituting the spreading means. As it passes from the lower end of the mandrel to the lower end of the spreading means, its cross section undergoes a transition from the circular cross section of the mandrel (see particularly FIG. 6) to the flattened cross section FT (see FIGS. 4 and 5) in the vertical plane in which the end sealers 17 form the package end seals. In this regard, it will be understood that on each downstroke of the end sealer carriage 15 carrying the end sealers 17, the latter are closed on the tubing and, while pulling the tubing downward one package length increment, act to form a transverse seal across the tubing (forming an end seal for the package being completed and an end seal for the next package to be formed), and the tubing is cut generally midway between the upper and lower edges of the transverse seal to separate the completed package from the tubing. At the end of their downstroke, the end sealers 17 open, and the carriage 15 and the end sealers move upward through a return stroke, during which interval the tubing dwells. The product with which the packages are to be filled (e.g., liquid milk) is delivered into the lower end of the tubing via the product delivery tube 19 and nozzle 31 during the intervals between formation of successive end seals, valve 67 being opened by means of air cylinder 79 for a time interval such as to provide the metered quantity of product to be delivered.

It will be observed that the vertical plane in which the end sealers 17 form the end seals is that diametrical plane of the mandrel 9 which extends transversely in respect to the machine 1 (i.e., from side-to-side). The lower chisel edges 60 of the spreader wings 53 lie generally in this plane, so that the tubing is flattened in this plane in passing downward off the lower end of the mandrel 9 to the carriage 15. The width of the lower end of the spreading means 37 (i.e., the distance between edges 58) corresponds generally to the circumference of the mandrel 9 for the flattening of the tubing. Thus, the lower end portion of the tubing below the spreading means, before delivery of the product thereto, is generally flat, having generally flat opposed front and back walls each having a width approximating half the circumference of the mandrel, with some space at 55 at the top thereof. The portions of the tubing passing downwardly over the converging front and back faces 57 of the spreading means 37 are pressed against these faces by the spring-biased presser plates 99 (which tend to move upward while being angled as shown in FIG. 4 for this purpose), and this in effect seals off the lower portion of the tubing below the spreading means 37 from the portion of the tubing (and the space 55 in the mandrel) above the spreading means except for the orifice 143.

When the product (e.g., liquid milk) is delivered via the nozzle 31 to the tubing below the spreading means 37, it bulges out the tubing, but the upper end portion of the tubing below the spreading means 37 remains flattened out for engagement by the end sealers 17, and the resultant package is accordingly partially deflated so that it is a soft package. The accuracy of delivery of the product to the tubing is maintained despite the spreading out and flattening of the tubing by means 37 and despite the pressing of the opposed walls of the tubing against faces 57 by the presser plates 99 due to the provision of the orifice 143, the size of which is selected (by selection of plug 139) in accordance with the amount of air or gas desired in the finished package.

By maintaining sterilized air in the space 87 in the mandrel 9 via line 85, outside air is excluded from the packages being formed. Only sterilized air from the mandrel may enter a package via the orifice 143. As previously noted, a sterilizing gas such as ethylene oxide may be used instead of sterilized air.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

What is claimed is:

1. A form-fill-seal packaging machine having a generally vertical mandrel around which a web of packaging material is formed into tubing, the tubing being fed downward off the lower end of the mandrel and formed, below the lower end of the mandrel, with transverse seals constituting package end seals at package length intervals, said end seals being formed in a generally vertical plane, means for delivering the product to be packaged to the lower end of the tubing below the lower end of the mandrel, and means below the lower end of the mandrel for effecting transition of the cross section of the tubing from the cross section of the mandrel to a flattened cross section generally in said plane, wherein said transition means is mounted so as to be disposed internally of the tubing and wherein said transition means has a passage providing for communication between the space in the mandrel above the transition means and the tubing below the transition means and having variable orifice means in said passage.

2. A form-fill-seal packaging machine having a generally vertical mandrel around which a web of packaging material is formed into tubing, the tubing being fed downward off the lower end of the mandrel and formed, below the lower end of the mandrel, with transverse seals constituting package end seals at package length intervals, said end seals being formed in a generally vertical plane, means for delivering the product to be packaged to the lower end of the tubing below the lower end of the mandrel, and means below the lower end of the mandrel for effecting transition of the cross section of the tubing from the cross section of the mandrel to a flattened cross section generally in said plane, wherein said transition means is mounted so as to be disposed internally of the tubing, wherein said transition means comprises means extending laterally outward beyond opposite sides of the mandrel below the lower end of the mandrel for spreading the tubing flat, said spreading means having flat faces converging toward one another in downward direction, and having means for pressing opposed walls of the tubing against said converging faces and wherein said spreading means has a passage providing for communication between the space in the mandrel above said spreading means and the tubing below said spreading means, and having variable orifice means in said passage.

3. A form-fill-seal packaging machine having a generally vertical mandrel around which a web of packaging material is formed into tubing, the tubing being fed downward off the lower end of the mandrel and formed, below the lower end of the mandrel, with transverse seals constituting package end seals at package length intervals, said end seals being formed in a generally vertical plane, means for delivering the product to be packaged to the lower end of the tubing below the lower end of the mandrel, and means below the lower end of the mandrel for effecting transition of the cross section of the tubing from the cross section of the mandrel to a flattened cross section generally in said plane, wherein the means for delivering the product comprises a product supply reservoir above the mandrel, a product supply tube extending from the reservoir down through the mandrel adapted to deliver the product to the lower end of the tubing below the mandrel, said transition means being mounted on the lower end of said product supply tube below the lower end of the mandrel so as to be disposed internally of the tubing, wherein said transition means has a passage providing for communication between the space in the mandrel above the transition means and the tubing below the transition means, and having variable orifice means in said passage.

4. A form-fill-seal packaging machine having a generally vertical mandrel around which a web of packaging material is formed into tubing, the tubing being fed downward off the lower end of the mandrel and formed, below the lower end of the mandrel, with transverse seals constituting package end seals at package length intervals, said end seals being formed in a generally vertical plane, means for delivering the product to be packaged to the lower end of the tubing below the lower end of the mandrel, and means below the lower end of the mandrel for effecting transition of the cross section of the tubing from the cross section of the mandrel to a flattened cross section generally in said plane, wherein the means for delivering the product comprises a product supply reservoir above the mandrel, a product supply tube extending from the reservoir down through the mandrel adapted to deliver the product to the lower end of the tubing below the mandrel, said transition means being mounted on the lower end of said product supply tube below the lower end of the mandrel so as to be disposed internally of the tubing, wherein said transition means comprises means extending laterally outward on opposite sides of said product supply tube beyond opposite sides of the mandrel below the lower end of the mandrel for spreading the tubing flat, said spreading means having flat faces converging toward one another in downward direction, and having means for pressing opposed walls of the tubing against said converging faces, wherein said spreading means has a passage providing for communication between the space in the mandrel above said spreading means and the tubing below said spreading means, and having variable orifice means in said passage.

5. A form-fill-seal packaging machine having a generally vertical mandrel around which a web of packaging material is formed into tubing, the tubing being fed downward off the lower end of the mandrel and formed, below the lower end of the mandrel, with transverse seals constituting package end seals at package length intervals, said end seals being formed in a generally vertical plane, means for delivering the product to be packaged to the lower end of the tubing below the lower end of the mandrel, and means below the lower end of the mandrel for effecting transition of the cross section of the tubing from the cross section of the mandrel to a flattened cross section generally in said plane, wherein the means for delivering the product comprises a product supply reservoir above the mandrel, a product supply tube extending from the reservoir down through the mandrel adapted to deliver the product to the lower end of the tubing below the mandrel, said transition means being mounted on the lower end of said product supply tube below the lower end of the mandrel so as to be disposed internally of the tubing, wherein said transition means comprises means extending laterally outward on opposite sides of said product supply tube beyond opposite sides of the mandrel below the lower end of the mandrel for spreading the tubing flat, said spreading means having flat faces converging toward one another in downward direction, and having means for pressing opposed walls of the tubing against said converging faces, wherein the product supply tube has a nozzle at its lower end and said spreading means comprises a central lower portion of the nozzle and two spreader wings flaring outward and downward from said central lower portion of the nozzle at diametrically opposite sides thereof, said central lower portion and said wings being of generally wedge-shaped cross section with inclined flat faces converging toward another in downward direction.

6. A form-fill-seal packaging machine as set forth in claim 5 wherein said pressing means comprises a pair of presser plates and means for biasing said presser plates toward said flat faces.

7. A form-fill-seal packaging machine as set forth in claim 5 wherein one of said spreader wings has a passage providing for communication between the space in the tubing above said wings and the space below and between the wings.

8. A form-fill-seal packaging machine as set forth in claim 7 having a removable partial plug in said passage.

9. A form-fill-seal packaging machine as set forth in claim 7 wherein the nozzle has an annular valve seat therein, and a valve engageable with said seat operable by a rod extending down through the supply tube.

10. A form-fill-seal packaging machine as set forth in claim 9 wherein the nozzle is removably mounted at its upper end in a bell on the lower end of the product supply tube.