GB2274797A - A method and appartus for forming side flanges on sheet material - Google Patents

Abstract

Apparatus (20) for forming longitudinal extending side flanges (8) on both sides of blank sheets of sheet metal of different widths comprises a main framework (22) which carries secondary frameworks (23) and (30) which form a passageway (25) for accommodating the passage of blank sheets therethrough. Bending rolls (31) to (34) are mounted on opposite sides of the passageway for sequentially forming the side flanges (8). The bending rolls (31) to (34) on one side of the passageway (25) are mounted on a fixed carrier housing (27). The bending rolls (31) to (34) on the other side of the passageway (25) are mounted on a movable carrier housing (28) which is transversely movable on transverse guide bars (44) for transversely adjusting the position of the bending rolls (31) to (34) on the movable carrier housing (28) relative to the bending rolls (31) to (34) on the carrier housing (27) for accommodating blanks sheets of different widths. <IMAGE>

Description

"A method and apparatus for forming side flanges on sheet material@' The present invention relates to a method and apparatus for forming longitudinally extending side flanges adjacent opposite side edges of a longitudinally extending sheet of sheet metal, and the invention also relates to a sheet formed according to the method and apparatus, as well as a method and apparatus for forming a heat insulating panel from the sheet and a heat insulating panel formed according to the method.

Cold stores, are in general, formed from a plurality of panels of heat insulating material. Such panels are generally referred to as insulating panels, and comprise a pair of spaced apart sheets of sheet metal between which is sandwiched heat insulating material.

For strength and rigidity longitudinally extending side flanges are generally formed adjacent opposite side edges of the sheets of sheet metal, and the side flanges extend longitudinally along the length of the sheet metal and inwardly therefrom relative to the panel. Transverse end flanges may also be provided adjacent the end edges of the sheets of sheet metal.

The insulating material may be one of many suitable heat insulating material, for example, expanded polystyrene, expanded polyurethane and the like. In general, where the heat insulating material is of expanded polystyrene the sheets of sheet metal are bonded to a sheet of expanded polystyrene. On the other hand, where the heat insulting material is expanded polyurethane, the two sheets of sheet metal are placed spaced apart in a mould and the polyurethane material in liquid form is pumped into the mould between the sheets of sheet metal. The polyurethane material cures and expands in the mould and adheres to the sheets of sheet metal.

Apparatus and methods for forming such insulating panels are known. Broadly speaking there are two types of processes for forming insulating panels, one a continuous process and the other a batch type process. In the continuous process two sheets of sheet metal are fed through forming apparatus from respective sheet metal rolls. Side flanges are formed on the respective sheets as they are fed through the apparatus. The sheets of sheet metal are bonded to insulating material also fed through the apparatus between the sheets of sheet metal. Insulating panels of the desired length are parted from the laminated sheets of sheet metal and insulating material. The batch process, in general, requires forming the sheets of sheet metal in a break press. Generally, side and end flanges are formed on the sheet metal sheets which have been cut to the appropriate size prior to bending.The side and end flanges are formed in a break press. The formed sheets of sheet metal are generally laminated to a sheet of insulating material.

This it will be appreciated is a relatively slow and tedious method. Where insulating panels of different transverse width are required, the side flanges must be formed on the sheet metal sheets using a break press. Continuous process apparatus are, in general, unsuitable for forming sheet metal sheets of different widths, and on which transverse end flanges are required.

There is therefore a need for a method and apparatus for forming longitudinally extending side flanges adjacent opposite side edges of longitudinally extending sheets of sheet metal of different widths.

There is also a need for a method and apparatus for forming a heat insulating panel.

The present invention is directed towards providing such methods and apparatus as well as a sheet of sheet metal formed according to the method and apparatus, and a heat insulating panel formed according to the method and apparatus.

According to the invention there is provided apparatus for forming longitudinally extending side flanges adjacent opposite side edges of longitudinally extending sheets of sheet metal material where the respective sheets are of different transverse width, the apparatus comprising a framework forming a longitudinally extending passageway for accommodating the sheets, a pair of main bending means located in the framework on respective opposite sides of the passageway for forming the side flanges, one of the main bending means being movable transversely of the passageway for accommodating sheets of different width, moving means for moving the movable main bending means transversely of the passageway, and drive means for feeding the sheet through the passageway.

In one embodiment of the invention the movable main bending means is mounted on a carriage, the carriage being slidable on guide means extending transversely of the passageway.

In another embodiment of the invention the guide means comprises a pair of spaced apart, parallel, elongated guide bars extending transversely of the passageway, the guide bars being engageable with corresponding bores in the carriage.

In a further embodiment of the invention the moving means comprises a pair of spaced apart, parallel, elongated lead screws extending transversely of the passageway, the lead screws being operatively engageable with the carriage for moving the carriage, and drive transmission means for transmitting drive between the lead screws. Preferably, a hand wheel is provided for driving the lead screws.

In one embodiment of the invention each main bending means bends a corresponding side flange through 900 relative to the sheet.

Preferably, each main bending means comprises a plurality of pairs of co-operating bending rolls for engaging the sheet, the pairs of bending rolls being sequentially arranged longitudinally relative to the passageway, the drive means for feeding the sheet through the passageway driving the bending rolls.

In one embodiment of the invention each main bending means comprises a first pair of co-operating bending rolls, one roll of each first pair of bending rolls comprising a bending flange for bending the flange through an angle of approximately 230.

In another embodiment of the invention each main bending means comprises a second pair of co-operating bending rolls, one roll of each second pair of bending rolls comprising a bending flange for bending the flange through a further angle of approximately 230.

In a further embodiment of the invention each main bending means comprises a third pair of co-operating bending rolls, one roll of each third pair of bending rolls comprising a bending flange for bending the flange through a further angle of approximately 230.

In a further embodiment of the invention each main bending means comprises a fourth pair of co-operating bending rolls, one roll of each fourth pair of bending rolls comprising a bending flange for bending the flange through a further angle of approximately 210.

Preferably, the pairs of co-operating bending rolls of respective main bending means are rotatably mounted in respective carrier housings.

Advantageously, the drive means comprises a pair of drive motors, one drive motor for driving the bending rolls of respective main bending means.

Advantageously, the bending rolls of each co-operating pair co-operate with each other for feeding the sheet through the passageway.

Preferably, alignment means are provided in the passageway for aligning each sheet in the passageway.

In one embodiment of the invention first secondary bending means is provided for forming a first transversely extending end flange adjacent one end edge thereof.

In another embodiment of the invention second secondary bending means is provided for forming a second transversely extending end flange adjacent an opposite end edge of the sheet.

Additionally the invention provides a method for forming longitudinally extending side flanges adjacent opposite side edges of longitudinally extending sheets of sheet metal material where the respective sheets are of different transverse width, using the apparatus as claimed in any preceding claim, the method comprising the steps of moving the movable main bending means transversely of the passageway for accommodating the width of the sheet to be fed through the passageway, entering the sheet in the passageway, feeding the sheet through the passageway and the main bending means for forming the side flanges. In one embodiment of the invention the method comprises a step of moving the carriage on the guide means. In another embodiment of the invention the method comprises a step of rotating the hand wheel for moving the carriage.In a further embodiment of the invention the method further comprises the step of forming a first end flange on one end of the sheet by bending the sheet transversely adjacent one end edge thereof between the side flanges.

In one embodiment of the invention the method comprises the further step of forming a second end flange on an opposite end of the sheet by bending the sheet transversely adjacent the said opposite end edge thereof between the side flanges.

Preferably, the method further comprises the step of notching the sheet by removing portion of the side flanges adjacent the ends thereof for facilitating the formation of the end flanges.

Further the invention provides a method for forming a heat insulating panel comprising at least one sheet formed according to the method of the invention, the method comprising the step of affixing a heat insulating material to the said sheet. Preferably, the heat insulating material is affixed between a pair of sheets formed according to the method of the invention.

Further the invention provides a sheet of sheet metal having a pair of side flanges formed according to the method of the invention.

Further the invention provides a heat insulating panel comprising a longitudinally extending sheet of sheet metal comprising longitudinally extending side flanges adjacent opposite side edges thereof, the sheet being formed on the apparatus according to the invention using the method according to the invention, and a sheet of insulating material parallel to the sheet of sheet metal, and secured thereto.

The invention will be more clearly understood from the following description of a preferred embodiment thereof given by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a cut away perspective view of a heat insulating panel according to the invention, Fig. 2 is an end view of the panel of Fig. 1, Fig. 3 is a side view of the panel of Fig. 1, Fig. 4 is a side elevational view of apparatus according to the invention for forming side and end flanges on a sheet metal blank, Fig. 5 is a perspective view of apparatus according to the invention for forming the side flanges of the sheet metal blank, Fig. 6 is another perspective view of the apparatus of Fig. 5, Fig. 7 is a side elevational view of the apparatus of Fig. 5, Fig. 8 is a plan view of the apparatus of Fig. 5 with portion of the apparatus removed, Fig. 9 is a side elevational view of a detail of the apparatus of Fig. 5, Figs. 10(a) to (e) are sectional end elevational views of parts of the detail illustrated in Fig.

9, Figs. ll(a) and (b) are sectional side elevational views of further details of the portion of the apparatus of Fig. 5, and Fig. 12 is a partly cutaway perspective view of the portion of the apparatus of Fig. 5 illustrated in use.

Referring to the drawings and initially to Figs. 1 to 3 there is illustrated a heat insulating panel indicated generally by the reference numeral 1 manufactured using methods and apparatus according to the invention. Before describing the methods and apparatus, the heat insulating panel 1 will first be described. The heat insulating panel 1 is of the type which is typically suitable for use in the construction of a cold store or cold room, (not shown). A plurality of panels 1 are abutted together, side edge to side edge, to form the cold room. The panel 1 comprises a pair of spaced apart identical sheets of sheet metal, namely, an inner sheet 2 and an outer sheet 3 which in use forms an inner and outer surface, respectively, of the wall of the cold room.

An internal sheet 4 of heat insulating material is affixed to and sandwiched between the inner and outer sheets 2 and 3. In this embodiment of the invention the internal sheet 4 is of expanded polyurethane material and is expanded in a mould between the inner and outer sheets 2 and 3. However, the internal sheet 4 may be of expanded polystyrene material, and in which case, the inner and outer sheets 2 and 3 would be bonded to the internal sheet 4. The construction of insulating panels 1 whether provided with an internal sheet 4 of expanded polyurethane material or expanded polystyrene material will be known to those skilled in the art. Longitudinally extending side flanges 8 extend longitudinally adjacent opposite side edges 9 of the sheets 2 and 3 and extend from the sheets 2 and 3 inwardly relative to the insulating panel 1.End flanges 10 extend transversely of the sheets 2 and 3 adjacent opposite end edges 11 and 12 thereof between the side flanges 8. The end flanges 10 also extend inwardly of the sheets 2 and 3 relative to the insulating panel 1. Spaced apart longitudinally, extending parallel reinforcing grooves 15 extend longitudinally of the inner and outer sheets 2 and 3 for reinforcing the insulating panel 1.

Tongues and grooves 16 and 17, respectively, are formed in opposite side edges 18 of the internal sheet 4 of the insulating panel 1 for facilitating abutment of adjacent insulating panels 1 in use.

Referring now to Figs. 4 to 12 apparatus according to the invention indicated generally by the reference numeral 19 for forming the inner and outer sheets 2 and 3 will now be described. The apparatus 19 comprises apparatus 20 also according to the invention for forming the longitudinally extending side flanges 8, and apparatus 21 for forming the transversely extending end flanges 10. The apparatus 20 and 21 are illustrated in block representation in Fig. 4. The apparatus 21 is briefly described below.

The apparatus 20 is suitable for forming the side flanges 8 of inner and outer sheets 2 and 3 of different transverse width to suit panels 1 of different width. The apparatus 20 comprises a framework formed by a main framework 22 and an input secondary framework 23 and an output secondary framework 30 both of which are mounted on the main framework 22. The main and secondary frameworks 22, 23 and 30 form a passageway 25 for accommodating a blank sheet 24 of metal therethrough from which the sheets 2 and 3 are formed, see in particular Fig. 12.

The input secondary framework 23 forms an entry 26 to the passageway 25, and the output secondary framework 30 forms an exit 35 from the passageway 25. In general, the blank sheets 24 from which the sheets 2 and 3 are to be formed are cut to the appropriate length and width to suit the final outer dimensions of the panel 1 prior to being fed into the passageway 25.

The reinforcing grooves 15 are also formed in the blank sheet 24 prior to it being fed into the passageway 25. A platform 29 supported on the secondary frameworks 23 and 30 supports the blank sheets 24 through the passageway 25, see Figs. 5 and 6.

A pair of carrier housings, namely, a fixed carrier housing 27 and movable carrier house 28 are mounted on the main framework 22 on opposite sides of the passageway 25. The carrier housings 27 and 28 carry respective bending means for forming the side flanges 8, each of which comprises a plurality of pairs of cooperating bending rolls, in this case, four pairs of co-operating bending rolls 31 to 34. The pairs of bending rolls 31 to 34 are described in detail below.

The fixed carrier housing 27 is rigidly mounted on a mounting member 39 mounted on the main framework 22.

The movable carrier housing 28 is mounted on a carriage 40 movable transversely relative to the passageway 25 for accommodating sheets 24 of different widths. In other words, the transverse distance across the passageway 25 between the bending rolls 31 to 34 carried on the respective carrier housings 27 and 28 may be varied for accommodating blank sheets 24 of different widths. A pair of spaced apart, parallel guide bars 44 extending transversely of the passageway 25 between the mounting member 39 and a side member 41 of the main framework 22 slidably carry the carriage 40. The guide bars 44 are rigidly mounted in the mounting member 39 and are carried on mounting blocks 42 on the side member 41. The guide bars 44 slidably engage guide bores 45 extending through the carriage 40.Moving means for moving the carriage 40 on the guide bars 44 comprises a pair of spaced apart, parallel lead screws 47 and 48 which extend transversely of the passageway 25 and are rotatably carried in bearings (not shown) in the mounting member 39 and in bearing members 46 on the side member 41 of the main framework 22. Ball nuts (not shown) in bores 49 in the carriage 40 engage the lead screws 47 and 48. A hand wheel 50 fast on the lead screw 47 rotates the lead screw 47. Transmission means comprising a drive chain 52 around sprockets 53 on the respective lead screws 47 and 48 transmit drive from the lead screw 47 to the lead screw 48 and ensures that the lead screws 47 and 48 rotates simultaneously and at the same speed.

Alignment means for aligning the blank sheets 24 in the passageway 25 comprises a plurality of spaced apart upper roller tracks 58 and spaced apart lower roller tracks 59 mounted on the input and output secondary frameworks 23 and 30. The roller tracks 58 and 59 extend longitudinally of the passageway 25 for engaging the reinforcing grooves 15 of the blank sheets 24 as the blank sheets 24 are sequently fed through the passageway 25. The roller tracks 58 and 59 are adjustably and releasably mounted on the secondary frameworks 23 and 30 for accommodating blank sheets 24 of different width and with different numbers and spacings of reinforcing grooves 15. The upper and lower roller tracks 58 and 59 adjacent the sides of the passageway 25 are arranged in pairs and co-operate with each other for engaging the reinforcing grooves 15.The upper roller tracks 58 towards the centre portion of the passageways 25 engage the grooves 15 and co-operate with the platform 29. Each roller track 58 and 59 comprises an elongated channel member 60 carrying a plurality of rotatably mounted rollers 64 for rollably engaging the reinforcing grooves 15, see Figs. ll(a) and (b). Lshaped mounting brackets 65 are provided adjacent the ends of each channel member 60 for releasably engaging transverse members 67 and 68 of the secondary frameworks 23 and 30, respectively. Clamping screws 66 through the mounting brackets 65 clamp the channel members 60 onto the transverse members 67 and 68 at desired locations corresponding to the positions of the reinforcing grooves 15.

Returning now to the pairs of bending rolls 31 to 34, and referring in particular to Figs. 9 and 10, each pair of bending rolls 31 to 34 comprises an upper roll 70 and a lower roll 71. The upper rolls 70 are rigidly mounted on respective shafts 72 rotatably carried in the corresponding carrier housings 27 and 28. The lower rolls 71 are rigidly mounted on respective shafts 73 which are rotatably carried in and extend from the corresponding carrier housings 27 and 28. Drive means comprising a pair of electrically powered drive motors 74 mounted on respective carrier housings 27 and 28 drive the shafts 72 and 73 through transmission means, namely, transmissions gear trains (not shown) mounted in the respective carrier housings 27 and 28. Such gear trains for driving bending rolls will be known to those skilled in the art.The upper and lower drive rolls 70 and 71 co-operate with each other for feeding the blank sheets 24 sequentially through the passageway 25 as the blank sheets engage between the upper and lower rolls 70 and 71. The lower rolls 71 each comprise a solid cylindrical portion 75 which is fast on the corresponding shaft 73. The upper rolls 70 comprise a solid cylindrical portion 76 of identical diameter to the cylindrical portions 75 of the lower rolls 71 which co-operates with cylindrical portion 75 of the lower roll 71 for feeding the sheets 24 through the passageway 25. The cylindrical portions 76 of the upper rolls 70 are rigidly mounted on the respective shafts 72. A bending flange 78 extends from the cylindrical portion 76 of each upper bending roll 70 for forming the longitudinally extending side flanges 8 of the sheets 2 and 3 downwardly relatively to the blank sheets 24 as the blank sheets 24 are fed sequentially through the passageway 25. The bending flange 78 of the upper roll 70 of each first pair of bending rolls 31 extends at an angle of approximately 300 to the rotational axis of the respective upper roll 70, and co-operates with the corresponding lower roll 71 for initially bending the side flange 8 of the blank sheet 24 through an angle of approximately 230. In other words, after the blank sheet 24 has passed through the two first pairs of bending rolls 31, the side flanges 8 make an included angle of approximately 1570 with the blank sheet 24.The bending flange 78 of the upper roll 70 of each second pair of bending rolls 32 extends at an angle of approximately 600 to the rotational axis of the respective upper roll 70, and co-operates with the corresponding lower roll 71 for bending the side flange 8 through a further angle of approximately 230, so that on the blank sheet 24 having passed through the second pairs of bending rolls 32, the side flanges 8 make an included angle of 1340 with the blank sheet 24.The bending flange 78 of the upper roll 70 of each third pair of bending rolls 33 extends at an angle of approximately 850 to the rotational axis of the respective upper roll 70 and co-operates with the corresponding lower roll 71 for bending the side flange 8 of the blank sheet 24 through a further angle of 230 so that on the blank sheet 24 having passed through the third pairs of bending rolls 33, the side flanges 8 make an included angle of approximately 1110 with the blank sheet 24.

The bending flange 78 of the upper roll 70 of each fourth pair of bending rolls 34 extends at an angle of approximately 900 to the rotational axis of the respective upper roll 70 and co-operates with the corresponding lower roll 71 for bending the side flange 8 through a further angle of 210 so that on the blank sheet 24 having passed through the fourth pairs of bending rolls 34, the side flanges 8 make an included angle of 900 with the blank sheet 24. Idler guide rolls 79 and 80 are rotatably carried on shafts 81 and 82, respectively, on the respective carrier housings 27 and 28 adjacent the exit 35 of the output secondary framework 30 for guiding the formed sheets 2 or 3 through the exit 35.

The apparatus 21 for forming the transverse end flanges 10 comprises a support platform 85 onto which sheets with the side flanges 8 formed thereon are fed from the apparatus 21. First and second secondary bending means are provided at respective ends of the platform 85 for forming respective first and second transversely extending end flanges adjacent to respective end edges of the sheet with the side flanges 8 formed thereon. The first secondary bending means is provided by a break press 86 at one end of the platform 85 and the second secondary bending means is provided by a break press 87 at the other end of the support platform 85. The first break press 86 forms the first end flange 10 adjacent the end 11 of the sheet, while the second break press 87 forms the end flange 10 adjacent the end 12 of the sheet.

Provision is made in the break press 86 to accommodate the passage of the sheets 2 and 3 with the side flanges 8 form thereon from the apparatus 20 onto the platform 85 of the apparatus 21. Such break presses 86 and 87 will be well known to those skilled in the art.

In use, the movable carrier housing 28 is moved transversely relative to the fixed carrier housing 27 by the hand wheel 50 until the spacing between the bending rolls 31 to 34 on the respective carrier housings 27 and 28 is at the desired spacing to provide sheets 2 and 3 of the desired width with side flanges 8. The appropriate number of upper and lower roller tracks 58 and 59 corresponding to the number of reinforcing grooves 15 in the sheets 2 and 3 are mounted on the secondary frameworks 23 and 30 and are spaced apart to engage the corresponding reinforcing grooves 15. The electrically powered motors 74 on the carrier housings 27 and 28 are activated for driving the upper and lower rolls 70 and 71 of the pairs of bending rolls 31 to 34.A blank sheet 24 cut the appropriate length and width and formed with the reinforcing grooves 15 is fed into the passageway 25 through the entry 26 in the input secondary framework 23 until the portions of the sheet 24 adjacent the side edges 9 are engaged between the rolls 70 and 71 of the pairs of first bending rolls 31 at which stage the pairs of first bending rolls 31 grip the sheet and feed the sheet through the passageway 25 as the sheet 24 is progressively fed through the passageway 25 the side flanges 8 are progressively formed by the pairs of bending rolls 31 to 34. The upper and lower rolls 70 and 71 of each pair of bending rolls 31 to 34 as well as forming the side flanges 8 also grip the sheet for feeding the sheet through the passageway 25.

The sheet with the side flanges 8 formed thereon is fed through the exit 35 of the output secondary framework 30 through the break press 86 and onto the support platform 85. Portions at 89 (see Figs. 1 to 3) of the side flanges 8 at the ends thereof are cut by notching to facilitate bending of the respective ends 11 and 12 of the sheet to form the end flanges 10. Portion of the sheet adjacent the end 12 is fed by hand into the break press 86 and the end 12 of the sheet is aligned in the break press 86. The break press 86 is activated for forming the end flange 10 adjacent the end 12. An end portion of the sheet at the other end 11 thereof is fed by hand into the break press 87 and aligned in the break press 87. The break press 87 is then activated for forming the end flange 10 adjacent the end 11. The formed sheet 2 or 3 is then removed from the apparatus 20.

When two sheets 2 and 3, namely, an inner sheet 2 and an outer sheet 3 have been formed with side flanges 8 and end flanges 10 the sheets 2 and 3 are placed spaced apart in an appropriately constructed timber mould (not shown). Such moulds will be well known to those skilled in the art. Liquid polyurethane is pumped into the mould between the sheets 2 and 3 and expanded therein for forming the internal heat insulating sheet 4 between the inner and outer sheets 2 and 3. The polyurethane expands, and as it cures bonds to the inner and outer sheets 2 and 3. On curing of the polyurethane being completed, the formed heat insulating panel 1 is removed from the mould and ready for use.

Alternatively, if the internal sheet 4 is of expanded polystyrene material, the inner and outer sheets 2 and 3 are bonded to the internal sheet 4 of polystyrene material.

While the apparatus 20 for forming the side flanges has been described as being of a particular shape and construction, the apparatus 20 may be of any other suitable shape and/or construction. Further, it will be appreciated that any means other than a carriage may be provided for transversely moving the movable bending means. Needless to say any other suitable bending means besides bending rolls may be provided and where bending rolls are provided more or less bending rolls may be provided.

It will or course be appreciated that other suitable alignment means besides roller tracks may be used, and indeed, in certain cases, the alignment means may be dispensed with.

Claims (32)

1. Apparatus for forming longitudinally extending side flanges adjacent opposite side edges of longitudinally extending sheets of sheet metal material where the respective sheets are of different transverse width, the apparatus comprising a framework forming a longitudinally extending passageway for accommodating the sheets, a pair of main bending means located in the framework on respective opposite sides of the passageway for forming the side flanges, one of the main bending means being moveable transversely of the passageway for accommodating sheets of different width, moving means for moving the moveable main bending means transversely of the passageway, and drive means for feeding the sheet through the passageway.

2. Apparatus as claimed in Claim 1 in which the moveable main bending means is mounted on a carriage, the carriage being slidable on guide means extending transversely of the passageway.

3. Apparatus as claimed in Claim 2 in which the guide means comprises a pair of spaced apart, parallel, elongated guide bars extending transversely of the passageway, the guide bars being engageable with corresponding bores in the carriage.

4. Apparatus as claimed in Claim 2 or 3 in which the moving means comprises a Fir of spaced apart, parallel, elongated lead screws extending transversely of the passageway, the lead screws being operatively engageable with the carriage for moving the carriage, and drive transmission means for transmitting drive between the lead screws.

5. Apparatus as claimed in Claim 4 in which a hand wheel is provided for driving the lead screws.

6. Apparatus as claimed in any preceding claim in which each main bending means bends a corresponding side flange through 900 relative to the sheet.

7. Apparatus as claimed in any preceding claim in which each main bending means comprises a plurality of pairs of co-operating bending rolls for engaging the sheet, the pairs of bending rolls being sequentially arranged longitudinally relative to the passageway, the drive means for feeding the sheet through the passageway driving the bending rolls.

8. Apparatus as claimed in Claim 7 in which each main bending means comprises a first pair of co-operating bending rolls, one roll of each first pair of bending rolls comprising a bending flange for bending the flange through an angle of approximately 230.

9. Apparatus as claimed in Claim 7 or 8 in which each main bending means comprises a second pair of cooperating bending rolls, one roll of each second pair of bending rolls comprising a bending flange for bending the flange through an angle of approximately 230.

10. Apparatus as claimed in any of Claims 7 to 9 in which each main bending means comprises a third pair of co-operating bending rolls, one roll of each third pair of bending rolls comprising a bending flange for bending the flange through an angle of approximately 230.

11. Apparatus as claimed in any of Claims 7 to 10 in which each main bending means comprises a fourth pair of co-operating bending rolls, one roll of each fourth pair of bending rolls comprising a bending flange for bending the flange through an angle of approximately 210.

12. Apparatus as claimed in any of Claims 7 to 11 in which the pairs of co-operating bending rolls of respective main bending means are rotatably mounted in respective carrier housings.

13. Apparatus as claimed in any of Claims 7 to 12 in which the drive means comprises a pair of drive motors, one drive motor for driving the bending rolls of respective main bending means.

14. Apparatus as claimed in any of Claims 7 to 13 in which the bending rolls of each co-operating pair cooperate with each other for feeding the sheet through the passageway.

15. Apparatus as claimed in any preceding claim in which alignment means are provided in the passageway for aligning each sheet in the passageway.

16. Apparatus as claimed in any preceding claim in which first secondary bending means is provided for forming a first transversely extending end flange adjacent one end edge thereof.

17. Apparatus as claimed in Claim 16 in which second secondary bending means is provided for forming a second transversely extending end flange adjacent an opposite end edge of the sheet.

18. Apparatus for forming longitudinally extending side flanges adjacent opposite side edges of a longitudinally extending sheet of sheet metal, the apparatus being substantially as described herein with reference to and as illustrated in the accompanying drawings.

19. A method for forming longitudinally extending side flanges adjacent opposite side edges of longitudinally extending sheets of sheet metal material where the respective sheets are of different transverse width, using the apparatus as claimed in any preceding claim, the method comprising the steps of moving the movable main bending means transversely of the passageway for accommodating the width of the sheet to be fed through the passageway, entering the sheet in the passageway, feeding the sheet through the passageway and the main bending means for forming the side flanges.

20. A method as claimed in Claim 19 in which the method comprises a step of moving the carriage on the guide means.

21. A method as claimed in Claim 20 in which the method comprises a step of rotating the hand wheel for moving the carriage.

22. A method as claimed in any of Claims 19 to 21 in which the method further comprises the step of forming a first end flange on one end of the sheet by bending the sheet transversely adjacent one end edge thereof between the side flanges.

23. A method as claimed in Claim 22 in which the method comprises the further step of forming a second end flange on an opposite end of the sheet by bending the sheet transversely adjacent the said opposite end edge thereof between the side flanges.

24. A method as claimed in Claim 22 or 23 in which the method further comprises the step of notching the sheet by removing portion of the side flanges adjacent the ends thereof for facilitating the formation of the end flanges.

25. A method for forming longitudinally extending side flanges adjacent opposite side edges of a longitudinally extending sheet of sheet metal, the method being substantially as described herein with reference to and as illustrated in the accompanying drawings.

26. A method for forming a heat insulating panel comprising at least one sheet formed according to the method of any of Claims 19 to 25, the method comprising the step of affixing a heat insulating material to the said sheet.

27. A method as claimed in Claim 26 in which the heat insulating material is affixed between a pair of sheets formed according to the method of any of Claims 19 to 25.

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

29. A sheet of sheet metal having a pair of side flanges formed according to the method of any of Claims 19 to 25.

30. A longitudinally extending sheet of sheet metal comprising longitudinally extending side flanges adjacent opposite side edges thereof, the sheet being substantially as described herein with reference to and as illustrated in the accompanying drawings.

31. A heat insulating panel formed according to the method of any of the Claims 26 to 28.

32. A heat insulating panel substantially as described herein with reference to and as illustrated in the accompanying drawings.