IE950051A1 - Apparatus and a method for manufacturing a flexible panel - Google Patents

Abstract

Apparatus (1) for manufacturing a flexible panel (2) comprising front and rear walls (5,7) an insulating wall (8) and a backing wall (9) with cavities (15) filled with a non-freezable liquid located between the front and rear walls (5) and (7). The apparatus comprises a main framework (20) which houses a first sealing station (32) for forming longitudinal seams (11) of the panel (2) and a second sealing station (34) located below the first sealing station (32) for forming transverse seams (12) of the panel (2). Dispensing nozzles (35) mounted on the main framework (12) above the first heat sealing station (32) dispense the non-freezable liquid into the cavities (15) after the longitudinal seams (11) are formed and one of the transverse seams (12) is formed. <Fig. 4>

Description

Apparatus and a method for manufacturing a flexible panel The present invention relates to apparatus and to a method for manufacturing a flexible panel of the type which comprises a front wall and a rear wall, both of flexible sheet material, the front and rear walls being joined along at least one seam to form at least one closed sealed cavity therebetween and having fluid sealably contained in each cavity.

Such panels have many uses, one typical use for such panels is for preserving food and drink by keeping the food and drink cool. In such cases, each cavity contains a liquid which is non-freezable at relatively low temperatures, typically down to -18°C. The panel is placed in a freezer for reducing the temperature of the liquid in the cavities to an appropriate temperature typically -15°C to -18°C, and the food and/or drink is then wrapped in the panel. Another use for such panels is to form the panel into a sleeve which may be slipped around a bottle, such as, for example, a wine bottle, a beverage can for chilling the contents therein after the liquid in the panel has been chilled. Such a panel, in general, comprises a plurality of discrete cavities, and in general, the cavities are filled or partly filled with-reins liquid OPEN TO PUBLIC INSPECTION UNDER SECTION 28 AND RULE 23 aTCL-£6=iC 3/07 JNL No.....H OF < f&SOo*< with a relatively low freezing point. This thus permits the liquid to be chilled to a relatively low temperature without freezing, and accordingly, even when chilled the panel remains flexible. In general, the cavities of such panels are formed by spaced apart longitudinally extending seams which forms the sides of the cavities, and the longitudinally extending seams are joined by spaced apart transversely extending seams which form top and bottom seams of each cavity.

The cavities may be of square shape, of rectangular shape and in many cases relatively elongated rectangular shape, particularly, where the panel is to be formed into a sleeve for chilling a wine bottle.

When the panel is formed into a sleeve, the cavities extend longitudinally relative to the sleeve axis.

This facilitates flow of the liquid longitudinally relative to the sleeve axis for accommodating different shapes and sizes of bottles.

Where such panels are used for chilling and/or maintaining food or beverages cooled, in general, the panels as well as comprising front and rear walls within which the cavities are formed, such panels also comprise an insulating wall which is generally attached to and adjacent the rear wall, and a backing wall which is attached to and adjacent the insulating wall. Thus, the insulating wall is sandwiched between the rear wall and the backing wall. The backing wall, in general, is of a foil, for example, a flexible aluminium foil sheet material. The insulating wall is of heat insulating material, typically, a flexible resilient closed cell polyethylene foam sheet material. The front and rear walls are of transparent flexible polythene sheet material. The foil backing wall in general is provided with a plastics coating on the side adjacent the insulating wall so that the longitudinal and transverse seams can be formed by heat welding the walls together along the seams .

Apparatus and methods for producing such panels are know, however, such apparatus and methods, in general suffer from various disadvantages.

There is therefore a need for an apparatus and method for manufacturing such panels.

The present invention is directed towards providing such apparatus.

According to the invention there is provided apparatus for manufacturing a flexible panel of the type comprising a front wall and a rear wall, both of flexible sheet material, the front and rear walls being ί> ft ft « L·· ’ S? joined along at least one seam to form at least one closed sealed cavity therebetween and having fluid sealably contained in each cavity, the apparatus comprising a first sealing station having first heat sealing means for forming at least two spaced apart longitudinally extending seams for forming side seams of each cavity, a second sealing station having a second heat sealing means for forming at least two spaced apart transverse seams extending transversely of the longitudinal seams and between the longitudinal seams for sealably closing each cavity, the first and second sealing stations defining a main path for accommodating the front and rear wall forming sheets of material therethrough, a supply means for supplying the front and rear wall forming sheets of material, an urging means for urging the front and rear wall forming sheets from the supply means and sequentially through the sealing stations, a dispensing means for dispensing the fluid into each cavity after formation of the longitudinal seams and after formation of one of the transverse seams of the cavities, but prior to the formation of the other transverse seam.

Preferably, the first heat sealing means comprises at least two first heat sealing members located in the first sealing station on one side of the main path, the first heat sealing members being spaced apart “ 9500 6 ι transversely of the direction of the main path, and a first anvil being provided on the opposite side of the main path for co-operating with the first heat sealing members for forming the longitudinal seams.

Advantageously, each first heat sealing member is a stationary member.

In one aspect of the invention a pair of first endless belts are provided in the first sealing station, one endless belt being provided on each side of the main path and extending through the first heat sealing station for engaging the adjacent wall forming sheets, the first endless belts being located between the first heat sealing members and the first anvil. Preferably, each endless belt is of heat conducting material and is of a non-stick material, and preferably of teflon material.

In one aspect of the invention each first heat sealing member comprises an elongated first heat sealing bar which is electrically heated, each first heat sealing bar extending parallel to the direction of the main path.

Preferably, the first heat sealing bars are heated by respective electrically powered cartridge heaters located therein.

? In another aspect of the invention a plurality of spaced apart first heat sealing members are provided for forming a plurality of spaced apart longitudinally extending seams, adjacent cavities sharing adjacent seams.

Preferably, the second heat sealing means comprises at least one elongated second heat sealing member located in the second heat sealing station on one side of the main path, the second heat sealing member extending transversely of the direction of the main path, and a second anvil being provided on the opposite side of the main path for co-operating with the second heat sealing member for forming the transverse seams.

Ideally, the urging means comprises a pair of second endless belts, located in the second sealing station, the second endless belts being located on respective opposite sides of the main path for engaging respective adjacent sheets of the front and rear wall forming sheets for urging the front and rear wall forming sheets through the first and second sealing stations, the second heat sealing member being located on one of the second endless belts and being movable therewith, and the second anvil being located on the other of the second endless belts and being movable therewith. •Τι» Preferably, each second endless belt comprises at least one endless chain carrying a plurality of transversely extending slats extending transversely of the chain and of the direction of the main path, the second heat sealing member being located on one of the slats of one of the second endless belts and the second anvil being located on one of the slats of the other of the second endless belts.

Preferably, two second heat sealing members are located substantially adjacent each other for forming adjacent transverse seams of adjacent cavities, and ideally, two second heat sealing members for forming adjacent transverse seams of adjacent cavities are located on the same transverse slat of one of the second endless belts .

Advantageously, each second heat sealing member comprises an electrically powered hot wire element. Preferably, each hot wire element is of substantially flat transverse cross-section. Advantageously, at least one end of each hot wire element terminates in a wiper contact which slidably engages an elongated electrically conductive track for receiving electrical power therefrom. Preferably, each electrically conductive track is stationary and is located in the second sealing station. a 5 ο ο 5 1 In one aspect of the invention a switch means cooperable with the wiper contact of each hot wire element is provided for switching on power to the electrically conductive track in response to the wiper member approaching the track.

Preferably, a timer means is responsive to the switch means for timing a predetermined period of time for switching off electrical power to the electrically conductive track on the timer means having timed the predetermined period of time.

In one aspect of the invention each end of the each hot wire element terminates in a wiper contact for engaging respective electrically conductive tracks, one of the electrically conductive tracks providing a live connection and the other of the electrically conductive tracks providing an earth connection.

In another aspect of the invention each second anvil comprises an elongated strip of heat insulating material, each elongated strip extending transversely of the direction of the main path. Preferably, each second anvil is of silicone rubber material.

Ideally, the second heat sealing members and the second anvils are covered by a heat conductive material with non-stick characteristics for preventing the sheet material sticking to the second heat sealing members and the second anvils.

In one embodiment of the invention the dispensing means comprises a dispensing nozzle. In one aspect of the invention a plurality of dispensing nozzles are provided spaced apart transversely of the direction of the main path, one dispensing nozzle being provided for each of the cavities in a row of cavities extending transversely of the main path.

Ideally, the first sealing station is located upstream of the second sealing station, and the dispensing means is located upstream of the first sealing station, and ideally, the first sealing station is vertically above the second sealing station, and the dispensing means is vertically above the first sealing station.

In one aspect of the invention a sensing means is provided for detecting the level of fluid in each cavity.

In another aspect of the invention the apparatus comprises a framework, the dispensing means, the first sealing station and the second sealing station being mounted in the framework.

Preferably, the urging means urges the front and rear wall forming sheets continuously through the main path.

In a particularly advantageous aspect of the invention the supply means comprises means for supplying four sheets of material, a first sheet to form the front wall of the cavity, a second sheet to form the rear wall of the cavity, a third sheet to form an insulating wall and a fourth sheet to form a backing wall so that the insulating wall is located adjacent the rear wall and the backing wall is located adjacent the insulating wall with the insulated wall sandwiched between the rear wall and the backing wall.

Additionally the invention provides a method for forming a flexible panel of the type comprising a front wall and a rear wall, both of flexible sheet material, the front and rear walls being joined along at least one seam to form at least one closed sealed cavity therebetween and having fluid sealably contained in each cavity using the apparatus according to the invention, the method comprising the steps of urging the front and rear wall forming sheets of material through the main path of the apparatus, forming spaced apart longitudinal seams to form each cavity in the first sealing station, forming spaced apart transverse seams of each cavity in the second sealing station, and >5005 1 on the longitudinal seams being formed and one of the transverse seams being formed, dispensing fluid into each cavity, and then forming the second of the transverse seams for sealably closing each cavity with the fluid contained therein.

Further the invention provides a panel comprising a front wall and a rear wall, both of flexible sheet material, the front and rear walls being joined along at least one seam to form at least one closed sealed cavity therebetween and having fluid sealably contained in each cavity.

Additionally, the invention provides a flexible panel formed using the method according to the invention, the flexible panel comprising a front wall and a rear wall, both of flexible sheet material, the front and rear walls being joined along at least one seam to form at least one closed sealed cavity therebetween and having fluid sealably contained in each cavity.

In one aspect of the invention the panel comprises a plurality of discrete cavities. Preferably, the panel further comprises an insulating wall and a backing wall, the insulating wall being located adjacent the rear wall, and the backing wall being located adjacent the insulating wall so that the insulating wall is $ Ο Ο 5 ? sandwiched between the rear wall and the backing wall.

In one aspect of the invention each cavity contains a non-freezable liquid.

Further the invention provides a sleeve formed from the 5 panel according to the invention, the front wall forming the inner wall of the sleeve.

In one aspect of the invention the sleeve is suitable for locating around a bottle.

In another aspect of the invention the sleeve is suitable for locating around a beverage can.

The invention will be more clearly understood from the following description of a preferred embodiment thereof which is given by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a sleeve according to the invention which has been manufactured from a panel also according to the invention which has been produced on apparatus according to the invention, Fig. 2 is a perspective view of the sleeve of Fig. in use, Fig. 3 is a cross-sectional elevational view of the sleeve of Fig. 1 in use, Fig. 4 is a sectional elevational view of portion 5 of the sleeve of Fig. 1, Fig. 5 is a plan view of part of a sheet comprising a plurality of panels according to the invention formed from the apparatus according to the invention, Fig. 6 is a partly sectional side elevational view of the apparatus according to the invention, Fig. 7 is a plan view of portion of the apparatus of Fig. 6 on the line VII-VII of Fig. 6, Fig. 8 is a sectional end elevational view of the 15 portion of the apparatus of Fig. 7 on the line VIII-VIII of Fig. 7, Fig. 9 is a sectional end elevational view of the portion of the apparatus of Fig. 7 on the line IX-IX of Fig. 7, ί 95 Ο Ο 51 Fig. 10 is a sectional plan view of another portion of the apparatus of Fig. 6 on the line X-X of Fig. 6, Fig. 11 is a sectional side elevational view of 5 part of the portion of the apparatus of Fig. 10, Fig. 12 is an end elevational view of a part of the portion of the apparatus of Fig. 10, Fig. 13 is an end view of another part of the portion of the apparatus of Fig. 10, and Fig. 14 is a block representation of an electrical circuit of the apparatus of Fig. 6.

Referring to the drawings there is illustrated apparatus according to the invention indicated generally by the reference numeral 1 for forming a plurality of flexible panels also according to the invention which are indicated generally by the reference numeral 2, see Fig. 5. Before describing the apparatus 1 in detail, the flexible panels 2 will first be described.

Each flexible panel 2 is of the type which may be formed into a sleeve 3 of the type illustrated in Figs. to 4 for cooling a wine bottle a beverage can or any other such container. The panel 2 comprises a front wall 5 which forms an inner wall 6 of the sleeve 3, a rear wall 7, an insulating wall 8 and a backing wall 9. The backing wall 9 forms an outer wall 10 of the sleeve 3. The front wall 5, rear wall 7, insulating wall 8 and backing wall 9 are secured together along a plurality of spaced apart longitudinally extending welded seams 11 which are joined by spaced apart transversely extending welded seams 12 which are formed by heat welding the walls 5, 7, 8 and 9 together. The longitudinal seams 11 and transverse seams 12 form six elongated rectangular cavities 15 between the front wall 5 and rear wall 7 which are partly filled with a liquid which is non-freezable to a relatively low temperature. In this embodiment of the invention the liquid is a mixture of water, glycol propylene and biocide, which is non-toxic, and which remains liquid at temperatures down to -18°C. Preferably, the liquid is coloured blue.

The front and rear walls 5 and 7 are of transparent flexible sheet polythene material of approximately 105 microns thickness. The backing wall 9 is formed from a sheet of non-elastic aluminium foil which is laminated with a flexible polyester sheet to facilitate heat welding of the backing wall 9 to the adjacent heat ®δ Ο Ο 5 I insulating wall. The heat insulating wall 8 is formed from a flexible sheet of resilient closed cell polyethylene foam material of approximately 1 mm thickness .

To form the panel 2 into a sleeve 3, side edges 16 adjacent the longitudinal seams 11 are heat welded together. This operation is not carried out on the apparatus 1.

Returning now to the apparatus 1, the apparatus 1 10 comprises a main framework 20 which extends vertically upwardly from a ground engaging base frame 21. A supply means for supplying sheets of material for forming the walls 5, 7, 8 and 9 of the panel 2 comprises a sub-framework 22 which extends upwardly from the base framework 21 and is secured by struts 23 extending from the main framework 20. The subframework 22 carries four rotatably mounted spindles 26 for carrying four rolls 27, 28, 29 and 30 from which first, second, third and fourth sheets of material are drawn for forming the front wall 5, the rear wall 7, the insulating wall 8 and the backing wall 9, respectively.

A first sealing station 32 within which the seven longitudinal seams 11 are formed by heat welding as » 5 ii 0 $ γ will be described below is mounted in the main framework 20 and defines part of a main path 33 through which the sheets from the rolls 27, 28, 29 and 30 are urged during forming of the panel 2. A second sealing station 34 is mounted in the main framework 20 below and downstream of the first sealing station 32 for forming the two transverse seams 12, namely, the top and bottom transverse seams 12 of each panel 2. The second sealing station 34 defines a lower part of the main part 33 through which the sheets from the rolls 27, 28, 29 and 30 are urged during forming of the panels 2.

A dispensing means, namely, a plurality, in this case, six dispensing nozzles 35 are mounted above and upstream of the first sealing station 32 for delivering the non-freezable liquid into the cavities 15 of the panel 2 after the longitudinal seams 11 have been formed and the bottom of the two transverse seams 12 has been formed. The dispensing nozzles 35 and their operation are described in detail below.

An urging means for urging the sheet material from the rolls 27, 28, 29 and 30 along the main path 33 through the first and second sealing stations 32 and 34 comprises two pairs of endless belts, namely, a first pair of endless belts 36 located in the first sealing station 32, and a second pair of endless belts 37 and 38 located in the second sealing station 34. The second pair of endless belts 37 and 38 are described below.

The first endless belts 32 are of teflon material, and are located on respective opposite sides of the main path 33, and are carried on rollers 39. The rollers 39 are rotatably mounted in sub-housings 40 and 41 which form part of the first sealing station 32. A drive motor (not shown) drives one of the rollers 39 in each sub-housing 40 and 41 through a drive transmission (also not shown) for driving the respective first belts 36 in the direction of the arrows A. The first endless belts 36 are arranged on the sub-housings 40 and 41 so that they present opposite working surfaces 42 which define the main path 33 through the first sealing station 32. The sheet material from the rolls 27, 28, 29 and 30 is sandwiched relatively tightly between the working surfaces 42 for urging the sheet material along the main path 33 through the first sealing station 32.

A first heat sealing means comprising seven spaced apart first heat sealing members, namely, elongated first heat sealing bars 43 are located in the subhousing 40 and are urged into engagement with an inner surface of the adjacent first belt 36 for forming the longitudinal seams 11 by heat welding. Seven corresponding spaced apart first anvil bars 45 are located in the sub-housing 41 adjacent an inner surface of the adjacent first belt 36 and co-operate with the heat sealing bars 43 for forming the longitudinal seams 11. The heat sealing bars 43 are slidably mounted on pairs of mounting brackets 46 which are in turn mounted to the sub-housing 40 by a carrier framework 47. The heat sealing bars 43 are slidable in the direction of the arrows B and are urged into engagement with the adjacent first belt 36 by compression springs 48 which act between the carrier framework 47 and the heat sealing bars 43. The force exerted by the springs 48 is such as to relatively tightly sandwich the first endless belts 36 and the sheet material from the rolls 27, 28, 29 and 30 between the first heat sealing bars and the first anvil bars 45 so that the sheets from the rolls 27, 28, 29 and 30 are pressed together with sufficient pressure for forming the welded longitudinal seams 11. The pressure of the first heat sealing bars 43 and the first anvil bars 45 on the first belts 36 also facilitates in gripping the sheets between the first belts 36 for urging the sheet material through the main path 33.

Electrically powered cartridge heaters 49 are inserted in bores 50 of the first heat sealing bars 43 for heating the first heat sealing bars 43 to the appropriate temperature for heat welding the sheets to form the longitudinal seams 11, see Fig. 7. The speed of the first belts 36 and the length of the first heat sealing bars 43 is chosen so that the amount of heat delivered to the sheets from the rolls 27, 28, 29 and 30 is sufficient for the purpose of forming good longitudinal welded seams 11, care being also taken to avoid any danger of damaging the sheets during heat welding.

The second endless belts 37 and 38 in the second heat sealing station 34 each comprise a pair of spaced apart endless chains 54 which are carried on sprockets 55.

The sprockets 55 are mounted on shafts 56 which are rotatably carried on the main framework 20. A drive motor (not shown) drives one of the shafts 56 of each second endless belt 37 and 38 through drive transmission (also not shown) for driving the second belts 37 and 38 in the direction of the arrows C for urging the sheets from the rolls 27, 28, 29 and 30 along the main path 33 through the second sealing station 34. The speed of the drive motors (not shown) for driving the first and second belts 36, 37 and 38 is synchronised so that both pairs of belts 36, and 37 and 38 urge the sheets along the main path 33 at the same speed. The chains 34 carry a plurality of transversely '950051 extending slats 57 of aluminium which effectively form the second endless belts 37 and 38.

A second heat sealing means comprising pairs of second heat sealing members, namely, pairs of adjacent hot wire elements 58 of copper and of relatively flat transverse cross-section are mounted on every fourth slat 57 of the second endless belt 37 for forming the transverse seams 12 of the panel 2. The hot wire elements 58 of each pair are located adjacent each other so that one of the adjacent hot wire elements 58 forms the bottom transverse seam 12 of one of the panels 2 and the other of the adjacent hot wire elements 58 forms the top transverse seam of an adjacent panel 2.

Second anvil bars 59 of teflon material are mounted on every fourth slat 57 of the second endless belt 38 for co-operating with the hot wire elements 58 on the second endless belt 37 for forming the transverse seams 12 as the belts 37 and 38 are driven in the direction of the arrows C.

Teflon sheets 60 secured to the second belts 37 and 38 cover the hot wire elements 58 and the second anvil bars 59 for preventing the sheet material sticking to the hot wire elements 58 and the second anvil bars 59 k Μ ® $ $ during welding. The second belts 37 and 38 are arranged relative to each other to provide opposite working surfaces 61 which define the main path 33 through the second sealing station 34. The sprockets 55 are arranged so that the sheet material from the rolls 27, 28, 29 and 30 is tightly clamped between the hot wire elements 58 and the second anvil bars 59 for urging the sheet material from the rolls 27, 28, 29 and 30 through the second sealing station 34 and for providing sufficient pressure for forming the transverse welded seams 12, while at the same time avoiding damage to the sheet material during forming of the welded seams 12.

Electrical power at 12 volts is delivered from a transformer 63 to the hot wire heating elements 58 (see circuit diagram of Fig. 14) through wiper contacts 64 connected to respective ends of the hot wire elements 58, see Figs. 10 and 11. The wiper contacts 64 slidably engage electrically conductive tracks 65 of brass which are carried in elongated carriers 76, which are in turn mounted to the main framework 20 by mountings 66, see Figs. 10 and 11. Electrical power is supplied to the tracks 65 from the transformer 63.

Each pair of hot wire elements 58 is stretched across a mounting strip 68 of electrically insulating and heat insulating material, namely, silicone rubber, which is 650051 secured to the corresponding slat 57. One end of each hot wire element 58 is anchored to an electrical contact 69 which is secured to and electrically insulated from the slat 57 by an insulator mounting 67. The other end of each hot wire element 58 is secured to an electrically conductive tension spring 70 for maintaining the hot wire element 58 taught during fluctuations in temperature of the hot wire element 58. Each tension spring 70 is in turn connected to a contact 71 mounted on a block of insulating material 72 extending from the corresponding slat 57. Wires 73 and 74 connect the electrical contacts 69 and 71 to corresponding respective wiper contacts 64 which are also secured to the corresponding slat 57. The wiper contacts 64 connected to the electrical contacts 69 are earth wiper contacts 64, and accordingly, are secured directly to the corresponding slat 57. The wiper contacts 64 connected to the electrical contacts 71 are live wiper contacts 64 and are electrically insulated by insulating blocks 75 from the corresponding slat 57.

The carriers 76 are of U-shaped cross-section and of electrically insulating material. The electrically conductive tracks 65 are mounted on corresponding elongated strips 78 of electrically insulating resilient plastics material on the inner surfaces of side webs 77 of the carriers 76. The resilient strips urge the tracks 75 into electrical engagement with the wiper contacts 64. At the leading end 83 of the live carrier 76, a micro switch 79 is mounted for engaging the wiper contacts 64 for switching on power to the tracks 65, see Fig. 11. An activating lever 80 of the micro switch 79 extends through a slot 81 between the side webs 77 of the carrier 76 for engaging the wiper contacts 64 as they enter between the side webs 77 of the carrier 76. A timing circuit 82 illustrated in block representation in the circuit diagram of Fig. 14 is responsive to the micro switch 79 being activated for timing a predetermined period of time during which power is delivered to the tracks 65 so that electrical power is delivered to the hot wire elements 58 for a predetermined time sufficient for forming the transverse seams 12, but is switched off before there is any danger of damage to the sheet material from the rolls 27, 28, 29 and 30 by overheating.

The six dispensing nozzles 35 are carried on a mounting bar 85 which is mounted at the top of the main framework 20. The nozzles 35 are spaced apart at appropriate distances for delivering the liquid into the cavities 15. Each nozzle 35 is fed with a feed tube 86 from a reservoir (not shown) of the non-freezable liquid. Delivery tubes 87 from the >500 5 I nozzles 35 extend downwardly into the main path 33 between the first belts 36 for a distance such that the longitudinal seams 11 are formed before the nonfreezable liquid exiting from the tubes 87 commences to enter the cavities 15.

Soft resilient pads 90 of foam rubber are provided on slats 57 of the second belt 38 between the slats 57 which carry the second anvil bars 59. The pads 90 cooperate with the working surface 61 of the second endless belt 37 for slightly deforming the cavities 15 for urging some of the non-freezable liquid out of the cavities 15 prior to formation of the top transverse seam 12 so that the cavities 15 will not be completely filled with the non-freezable liquid. This allows the deformation of the panel 2 and cavities 15 in use, and where the panel is formed into the sleeve 3 deformation of the cavities allows the sleeve 3 to be used with a wide range of shapes of bottles.

A sensing means comprising six photoelectric sensors 88 illustrated in block representation in Fig. 6 monitor each of the cavities 15 to ensure that each cavity has been charged with the non-freezable liquid. On a cavity 15 being detected as not having been charged, the apparatus is deactivated. The sensors 88 are connected to control circuitry (not shown) for deactivating the apparatus 1 in the event of detection of an uncharged cavity.

Rollers 89 are provided at the top of the main framework 20 for directing the sheet material from the rolls 27, 28, 29 and 30 to the main path 33 through the first heat sealing station 32 so that the sheet forming the front wall 5 lies to one side of the dispensing nozzles 35 while the sheet forming the rear wall 7 lies to the other side of the dispensing nozzles 35, and the sheet forming the insulating wall 8 lies next to the rear wall 7 and the sheet forming the backing wall 9 lies next to the insulating wall 8, so that in this way the cavities 15 are formed between the front wall 5 and rear wall 7 in the panel 2 and the insulating wall 8 is sandwiched between the rear wall 7 and the backing wall 9.

In use, with the rolls 27, 28, 29 and 30 mounted on the appropriate spindles 26, and the sheet material from the rolls fed over the rollers 89 and through the main path 33 in the appropriate relationship, power is delivered to the apparatus 1 and the non-freezable liquid is delivered to the dispensing nozzles 35. The first belts 36 and the second belts 37 and 38 are driven continuously for continuously drawing the sheets from the roller 27, 28, 29 and 30 through the main path 33. As the sheets are drawn through the main path 33 in the first sealing station 32 the longitudinal seams 11 are formed by the co-operation of the first heat sealing bars 43 and the first anvil bars 45. The transverse seams 12 are formed by the co-operation of the hot wire elements 58 with the corresponding second anvil bars 59 on the second belts 38 and 37, respectively. The non-freezable liquid is delivered into the cavities 15 on the longitudinal seams 11 being formed and the bottom transverse seams 12 being formed. Any cavity 15 not charged with the non-freezable liquid is detected by the sensors 88 which deactivate the apparatus 1. As the wiper contacts 64 enter the corresponding carrier 76 the wiper contacts 64 activate the micro switch 79 which in turn activates the timing circuit 82. The timing circuit 82 applies power to the tracks 65 of the carrier 76 for powering the hot wire elements 58 until it has timed the predetermined time period. In this embodiment of the invention the timer is set to time a predetermined time period of three seconds, after which the tracks 65 are isolated from the transformer 63. The tracks 65 remain unpowered until the wiper contact 64 of the next pair of hot wire elements 58 enter the carrier 76 and trip the micro switch 79. The soft resilient pads 90 on the slats 57 of the second belt 38 co-operate with the second belts 37 for preventing full filling of the cavities 15 so k850051 that the cavities 15 are only partly filled with the non-freezable liquid. The formed panels 2 are delivered continuously in a continuous formed sheet from the apparatus 1. A guillotine (not shown) is provided at the bottom of the main framework 20 for cutting the continuous formed sheet into the panels 2 between adjacent transverse seams 12 which form the top transverse seam 12 of one panel and a bottom transverse seam 12 of the next adjacent panel 2.

The advantages of the invention are many. A particularly important advantage of the invention is that the apparatus is a continuous apparatus which continuously forms the panels 2. Thus, the need for indexing on the sheets of material on a stop start basis for forming the longitudinal and transverse seams is avoided. Accordingly, the apparatus produces the panels on a continuous basis and has a relatively high output. Additionally, the apparatus produces panels of particularly good quality, since the heat delivered to the sheet material for heat welding the longitudinal and transverse seams can be precisely controlled thereby providing good heat welded seams, while at the same time avoiding damage to the sheet material by, overheating or the like.

While the apparatus has been described for manufacturing a panel with six elongated side by side cavities, the apparatus may be used for manufacturing panels with any number of cavities, and instead of the cavities being of elongated rectangular shape, they may be of square shape or any other desired shape, and a plurality of cavities may be formed longitudinally and transversely. For example, the panel may be provided of a quilted type construction having N rows and M columns of cavities 15, where N and M are whole numbers from one upwards .

It will be appreciated that the number of first heat sealing bars, and their spaced apart relationship will depend on the number and transverse width of the cavities to be formed in each transverse row of cavities across the panel. Likewise, the number of dispensing nozzles and their location will also depend on the number of cavities to be formed in each transverse row of cavities. The number of hot wire elements and their spaced relationship on the second endless belts 37 will depend on the number of transverse rows of cavities to be provided in each panel, and also on the longitudinal length of each cavity. It should be readily apparent to those skilled in the art as to how the first heat sealing bars, the hot wire elements and the dispensing nozzle should be arranged to achieve panels with the desired number, size and location of cavities.

It will also of course be appreciated that in many cases the panels may be formed with only a front wall and a rear wall.

It will also be appreciated that the cavities may be filled with any other fluid or liquid besides a nonfreezable liquid.

Claims (41)

CLAIMS.

1. Apparatus for manufacturing a flexible panel of the type comprising a front wall and a rear wall, both of flexible sheet material, the front and rear walls being joined along at least one seam to form at least one closed sealed cavity therebetween and having fluid sealably contained in each cavity, the apparatus comprising a first sealing station having first heat sealing means for forming at least two spaced apart longitudinally extending seams for forming side seams of each cavity, a second sealing station having a second heat sealing means for forming at least two spaced apart transverse seams extending transversely of the longitudinal seams and between the longitudinal seams for sealably closing each cavity, the first and second sealing stations defining a main path for accommodating the front and rear wall forming sheets of material therethrough, a supply means for supplying the front and rear wall forming sheets of material, an urging means for urging the front and rear wall forming sheets from the supply means and sequentially through the sealing stations, a dispensing means for dispensing the fluid into each cavity after formation of the longitudinal seams and after formation of one of the transverse seams of the cavities, but prior to the formation of the other transverse seam.

2. Apparatus as claimed in Claim 1 in which the first heat sealing means comprises at least two first heat sealing members located in the first sealing station on one side of the main path, the first heat sealing members being spaced apart transversely of the direction of the main path, and a first anvil being provided on the opposite side of the main path for cooperating with the first heat sealing members for forming the longitudinal seams.

3. Apparatus as claimed in Claim 2 in which each first heat sealing member is a stationary member.

4. Apparatus as claimed in Claim 2 or 3 in which a pair of first endless belts are provided in the first sealing station, one endless belt being provided on each side of the main path and extending through the first heat sealing station for engaging the adjacent wall forming sheets, the first endless belts being located between the first heat sealing members and the first anvil.

5. Apparatus as claimed in Claim 4 in which each endless belt is of heat conducting material and is of a non-stick material.

6. Apparatus as claimed in Claim 4 or 5 in which each c ο; · endless belt is of teflon.

7. Apparatus as claimed in any of Claims 2 to 6 characterised in that each first heat sealing member comprises an elongated first heat sealing bar which is electrically heated, each first heat sealing bar extending parallel to the direction of the main path.

8. Apparatus as claimed in Claim 7 in which the first heat sealing bars are heated by respective electrically powered cartridge heaters located therein.

9. Apparatus as claimed in any of Claims 2 to 8 in which a plurality of spaced apart first heat sealing members are provided for forming a plurality of spaced apart longitudinally extending seams, adjacent cavities sharing adjacent seams.

10. Apparatus as claimed in any preceding claim in which the second heat sealing means comprises at least one elongated second heat sealing member located in the second heat sealing station on one side of the main path, the second heat sealing member extending transversely of the direction of the main path, and a second anvil being provided on the opposite side of the main path for co-operating with the second heat sealing member for forming the transverse seams. LH 0 0 5 1

11. Apparatus as claimed in Claim 10 in which the urging means comprises a pair of second endless belts, located in the second sealing station, the second endless belts being located on respective opposite sides of the main path for engaging respective adjacent sheets of the front and rear wall forming sheets for urging the front and rear wall forming sheets through the first and second sealing stations, the second heat sealing member being located on one of the second endless belts and being movable therewith, and the second anvil being located on the other of the second endless belts and being movable therewith.

12. Apparatus as claimed in Claim 11 in which each second endless belt comprises at least one endless chain carrying a plurality of transversely extending slats extending transversely of the chain and of the direction of the main path, the second heat sealing member being located on one of the slats of one of the second endless belts and the second anvil being located on one of the slats of the other of the second endless belts .

13. Apparatus as claimed in any of Claims 10 to 12 in which two second heat sealing members are located substantially adjacent each other for forming adjacent transverse seams of adjacent cavities. Ρ & 5 0 ΰ 5 ΐ

14. Apparatus as claimed in Claim 13 in which two second heat sealing members for forming adjacent transverse seams of adjacent cavities are located on the same transverse slat of one of the second endless belts .

15. Apparatus as claimed in any of Claims 10 to 14 in which each second heat sealing member comprises an electrically powered hot wire element.

16. Apparatus as claimed in Claim 15 in which each hot wire element is of substantially flat transverse crosssection .

17. Apparatus as claimed in Claim 15 or 16 in which at least one end of each hot wire element terminates in a wiper contact which slidably engages an elongated electrically conductive track for receiving electrical power t here from.

18. Apparatus as claimed in Claim 17 in which each electrically conductive track is stationary and is located in the second sealing station.

19. Apparatus as claimed in Claim 17 or 18 in which a switch means co-operable with the wiper contact of each hot wire element is provided for switching on power to the electrically conductive track in response to the wiper member approaching the track.

20. Apparatus as claimed in Claim 19 in which a timer means is responsive to the switch means for timing a predetermined period of time for switching off electrical power to the electrically conductive track on the timer means having timed the predetermined period of time.

21. Apparatus as claimed in any of Claims 17 to 20 in which each end of the each hot wire element terminates in a wiper contact for engaging respective electrically conductive tracks, one of the electrically conductive tracks providing a live connection and the other of the electrically conductive tracks providing an earth connection.

22. Apparatus as claimed in any of Claims 10 to 21 in which each second anvil comprises an elongated strip of heat insulating material, each elongated strip extending transversely of the direction of the main path.

23. Apparatus as claimed in any of Claims 10 to 22 in which each second anvil is of silicone rubber material.

24. Apparatus as claimed in any of Claims 10 to 23 in which the second heat sealing members and the second anvils are covered by a heat conductive material with non-stick characteristics.

25. Apparatus as claimed in any preceding claim in which the dispensing means comprises a dispensing nozzle.

26. Apparatus as claimed in Claim 25 in which a plurality of dispensing nozzles are provided spaced apart transversely of the direction of the main path.

27. Apparatus as claimed in any preceding claim in which the first sealing station is located upstream of the second sealing station, and the dispensing means is located upstream of the first sealing station.

28. Apparatus as claimed in any preceding claim in which the first sealing station is vertically above the second sealing station, and the dispensing means is vertically above the first sealing station.

29. Apparatus as claimed in any preceding claim in which a sensing means is provided for detecting the level of fluid in each cavity. ϊ 95 00 5 1

30. Apparatus as claimed in any preceding claim in which the apparatus comprises a framework, the dispensing means, the first sealing station and the second sealing station being mounted in the framework.

31. Apparatus as claimed in any preceding claim in which the urging means urges the front and rear wall forming sheets continuously through the main path.

32. Apparatus as claimed in any preceding claim in which the supply means comprises means for supplying four sheets of material, a first sheet to form the front wall of the cavity, a second sheet to form the rear wall of the cavity, a third sheet to form an insulating wall and a fourth sheet to form a backing wall so that the insulating wall is located adjacent the rear wall and the backing wall is located adjacent the insulating wall with the insulated wall sandwiched between the rear wall and the backing wall.

33. Apparatus substantially as described herein with reference to and as illustrated in the accompanying drawings.

34. A method for forming a flexible panel of the type comprising a front wall and a rear wall, both of flexible sheet material, the front and rear walls being joined along at least one seam to form at least one closed sealed cavity therebetween and having fluid sealably contained in each cavity using the apparatus of any preceding claim, the method comprising the steps of urging the front and rear wall forming sheets of material through the main path of the apparatus, forming spaced apart longitudinal seams to form each cavity in the first sealing station, forming spaced apart transverse seams of each cavity in the second sealing station, and on the longitudinal seams being formed and one of the transverse seams being formed, dispensing fluid into each cavity, and then forming the second of the transverse seams for sealably closing each cavity with the fluid contained therein.

35. A method for forming a flexible panel, the method being substantially as described herein with reference to and as illustrated in the accompanying drawings.

36. A flexible panel formed on the apparatus of any of Claims 1 to 33, the panel comprising a front wall and a rear wall, both of flexible sheet material, the front and rear walls being joined along at least one seam to form at least one closed sealed cavity therebetween and having fluid sealably contained in each cavity.

37. A flexible panel formed using the method of Claims ϋ* & L 0 Γ, \ 4 34 and 35, the flexible panel comprising a front wall and a rear wall, both of flexible sheet material, the front and rear walls being joined along at least one seam to form at least one closed sealed cavity 5 therebetween and having fluid sealably contained in each cavity.

38. A flexible panel as claimed in Claim 36 or 37 in which the panel comprises a plurality of discrete cavities . 10 39. A flexible panel as claimed in any of Claims 36 to 38 in which the panel further comprises an insulating wall and a backing wall, the insulating wall being located adjacent the rear wall, and the backing wall being located adjacent the insulating wall so that the 15 insulating wall is sandwiched between the rear wall and the backing wall. 40. A flexible panel as claimed in any of Claims 36 to

39. In which each cavity contains a non-freezable liquid. 20 41. A sleeve formed from the panel of any of Claims 36 to 40, the front wall forming the inner wall of the sleeve. .9 5 Ο Ο 5 1

40. 42. A sleeve as claimed in Claim 41 in which the sleeve is suitable for locating around a bottle.

41. 43. A sleeve as claimed in Claim 41 in which the sleeve is suitable for locating around a beverage can