- 1 A PACKAGING MACHINE AND FORMER Technical Field The present invention relates to packaging machines and their associated formers, and more particularly but not exclusively to vertical form fill and seal packaging 5 machines and their formers. Background of the Invention Packaging machines such as those described in US Patent No. 4,753,336 receive tubular bag material into which product is delivered. The machine transversely seals and cuts the tubular bag material to form discreet bags. 10 The above mentioned tubular bag material is provided by a former. The former receives bag material in strip form and reconfigures it into a tubular configuration. The size of the tubular bag material is determined by the former. More particularly, bags of a required size are produced with the user of a former designed to produce tubular bag material to suit that particular size bag. is Factories often produce a variety of products, with each of the products frequently being contained in different size bags. Accordingly formers need to be regularly changed to suit different products and different bag sizes. To prolong the life of some packaged products it is necessary to reduce the amount of oxygen within the bag. This is usually achieved by delivering nitrogen to the 20 former and having the nitrogen contained in the bags. To deliver the nitrogen to the former there is provided a separate gas supply line. The above discussed construction of formers suffers a number of disadvantages in that it is difficult and time consuming to replace the formers and their associated gas lines. During replacement of a former the associated packaging machine is unusable. 25 Accordingly there is a piece of expensive apparatus that is lying idle. Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.
-2 Summary of the Invention There is disclosed herein a packaging machine former to engage an upwardly projecting locating spigot of a packaging machine, the spigot including a gas outlet, the former including: 5 a base having a socket to receive the spigot so that the former is located thereby with respect to the machine; a former member over which strip bag material passes to be configured into tubular bag material, the former member providing a generally vertically oriented product passage into which product is deposited for delivery into the tubular bag material; and 10 wherein said base and member provide gas passages that communicate with the socket so to receive a gas from said spigot and deliver the gas to said product passage. Preferably, said gas passages extend to said former member so as to deliver the gas to said product passage. Is Preferably, said former includes a backing member extending downwardly from the base, and wherein said gas passages extend through said backing member to deliver said gas to the interior of the tubular bag material. Preferably, the former is configured to engage a packaging machine having a pair of upwardly extending locating spigots, each spigot providing a gas outlet, and 20 wherein said socket is a first socket, and said base has a second socket, with the sockets being positioned to each respectively receive a respective one of the spigots so as to receive gas therefrom, with the gas passages communicating with each socket. There is further disclosed herein a mounting upon which a packaging former is to rest so as to be supported thereby, and wherein said mounting includes an upwardly 25 extending spigot to received by the former to locate the former with respect to the machine, said spigot including a gas passage to which a gas is for delivery to the former, and a moveable valve member operatively associated with the passage so as to be moveable between a first position closing said passage, and a second position permitting gas to pass through said passage, said moveable valve member being urged to the first 30 position and moved to the second position upon engagement with the former.
-3 There is still further disclosed herein, in combination the packing machine former and packaging machine described above. Brief Description of the Drawings A preferred form of the present invention will now be described by way of 5 example with references to the accompanying drawings wherein: Figure 1 is a schematic front elevation of a packaging machine former and portion of a packaging machine; Figure 2 is a schematic side elevation of the former and packaging machine of Figure 1; to Figure 3 is a schematic front elevation of the former of Figure 1 mounted on the packaging machine of Figure 1; Figure 4 is a schematic side elevation of the former and packaging machine of Figure 3; Figure 5 is a schematic sectioned front elevation of a mounting spigot of the is packaging machine of Figure 1; Figure 6 is a further schematic side elevation of the mounting spigot of Figure 5; and Figure 7 is a schematic sectioned elevation of the spigot of Figures 5 and 6 with portion of the former mounted thereon. 20 Detailed Description of the Preferred Embodiment In the accompanying drawings there is schematically depicted a packaging machine former 10. The former 10 includes a base I1 upon which there is mounted a former member 12 (shoulder) to which strip bag material is delivered to be configured into tubular bag material. Extending upwardly from the upper portions of the former 25 member 12 is a chute 13 terminating at its upper edge with a hollow rim 14. Attached to and extending downwardly from the base 11 is a backing member 32 against which the tubular bag material would pass so that overlapping longitudinal edge portions of the bag material can be engaged by a heater to form a longitudinal seal in the -4 tubular bag material. Typically, the heater is a bar which slides/drags over the bag material. The base 11 includes a pair of sockets 15 that are positioned to engage upwardly projecting spigots 16 of the packaging machine 33. The spigots 16 are gas outlets and s deliver gas to the former 10. Extending from sockets 15 are tubes 17 that communicate with further tubes 18 to distribute a gas such as nitrogen to various internal portions of the vertical passage 20 of the former 10. More particularly product is delivered to the passage 20 to be located internally of the tubular bag material. A tube 34 extends from the tube 17 to an air bleed 10 fitting located on former member 12. This tube 34 can be used to provide an air bearing between the former member 12 and the bag material to reduce friction therebetween. The tube 18 communicates with the rim 14 so as to deliver gas thereto. The rim 14 is provided with a single annular aperture or a plurality of apertures so that the nitrogen is delivered to the upper end of the passage 20. The lower tube 18 15 communicates with the lower end of the chute 13 again to deliver nitrogen thereto. Internally of the base 11 is a passage that communicates with an internal passage of the backing member 32 again to deliver nitrogen to a position internally of the tubular bag material. Accordingly the tubes 17 and 18, rim 14 and backing member 32 provide passages via which a gas such as nitrogen is mixed with the product and contained in the 20 tubular bag material to minimise the amount of oxygen in the bags produced. Each socket 15 includes a cavity 19 that receives an associated one of the spigots 16. Each spigot 16 includes a base 21 having an internal passage 22 that communicates with a tube 23 via which nitrogen is delivered to the spigots 16. Attached to and extending upwardly from the base 21 is a hollow generally cylindrical projection 24 25 providing a generally upwardly extending passage 25. Slidably mounted in the projection 24 is a moveable valve member 26 having a head 27 located above the projection 24. The moveable valve member 26 is urged by means of a spring 28 to its upper most position as illustrated in Figure 5. The head 27 provides an annular recess 29 that cooperates with the passage 25 to 30 release the nitrogen. The annular recess 29 is positioned as shown in Figure 6 allowing -5 the escape of the nitrogen by engagement of the head 27 with the upper surface of the cavity 19. The projection 24 has an upper aperture 30 through which the moveable valve member 26 projects. The aperture 30 is provided by an annular flange 31 that is abutted s by the moveable valve member 26 when the valve member 26 is in its uppermost position to be thereby captively located by the annular flange 31. The above described preferred embodiment facilitates quick removal and mounting of the former 10 on the packaging machine 33 while providing for automatic gas connection. In particular by having the sockets 15 engage spigots 16 correct 1o alignment of the former 10 with respect to the packaging machine 33 is assured.