Title of Invention	AN INSULATING PANEL FOR A CONDITONED AIR-DISTRIBUTION DUCT
Abstract	An insulating panel (2) for a conditioned-air distribution duct (1), said insulating panel (2) comprising at least one insulating core (3) based on mineral wool, preferably on rock wool, and possibly comprising an exterior layer (4) for example based on a thin skin of aluminium, characterized in that on one exterior face it has a plurality of marks (5) that are straight and oblique with respect to a longitudinal direction of said panel, said marks forming two sets of opposing inclinations oriented at an angle γ with respect to said longitudinal direction.

Title of Invention

AN INSULATING PANEL FOR A CONDITONED AIR-DISTRIBUTION DUCT

Abstract

An insulating panel (2) for a conditioned-air distribution duct (1), said insulating panel (2) comprising at least one insulating core (3) based on mineral wool, preferably on rock wool, and possibly comprising an exterior layer (4) for example based on a thin skin of aluminium, characterized in that on one exterior face it has a plurality of marks (5) that are straight and oblique with respect to a longitudinal direction of said panel, said marks forming two sets of opposing inclinations oriented at an angle γ with respect to said longitudinal direction.

Full Text	The present invention relates to an insulating panel for a duct for distributing conditioned air, said insulating panel comprising at least one insulating core based on mineral wool, preferably on rock wool, and possibly comprising an exterior layer for example based on a thin skin of aluminum. The present invention relates more specifically to the manufacture, in buildings, of ducts for transporting and distributing conditioned air. Such ducts generally have a metal structure made up of a self-supporting framework and of metal sheets arranged between the members of this framework, and on the inside of this duct, insulation made from insulating panels. The manufacture of these ducts for transporting and distributing conditioned air entails the incorporation of changes in direction to the duct, so as to distribute air to various points. The prior art discloses a method for manufacturing insulating ducts whereby the direction-change angle is broken down into a great many angles of smaller magnitude. Thus, according to that method, the change in direction is very gradual and the intrinsic parameters of the air stream are modified only slightly as the stream gradually progresses through the change in direction. The purpose of the invention is to make it possible to reduce the head losses generated in the changes in direction produced according to the method of the prior art, while at the same time making the changes in direction easier to produce. The subject of the present invention is therefore an insulating panel for a duct for distributing conditioned air according to claim 1. This insulating panel comprises at least one insulating core based on mineral wool, preferably on rock wool, and possibly comprises an exterior layer for example based on a thin skin of aluminum. This panel also has, on an exterior face, a plurality of marks that are straight and oblique with respect to a longitudinal direction of said panel, said marks forming two sets of opposing inclinations oriented at an angle ? with respect to said longitudinal direction. Said angle y is preferably substantially between 82.5° and 52.5° and more preferably still is substantially equal to 67.5°. Said exterior face of the panel also preferably has a plurality of transverse straight marks oriented at right angles to said longitudinal direction and, also as a preference, a plurality of longitudinal straight marks oriented parallel to said longitudinal direction. Said oblique straight marks, and possibly said transverse straight marks and/or said longitudinal straight marks are preferably embodied at least near the longitudinal edges and preferably across the entire surface of the exterior face. Said oblique straight marks, and possibly said transverse straight marks and/or said longitudinal straight marks are preferably embodied on the surface of the exterior face of the exterior layer of the panel. In an alternative form, said transverse straight marks and/or said longitudinal straight marks intersect said oblique straight marks at points where longitudinal straight marks of opposing inclination intersect. The oblique, transverse and straight guide marks- thus make insulating ducts easier to manufacture and allow a saving in time and an increase in accuracy when marking out and cutting on site. The marks are designed to coincide on the four faces of the duct once the necessary cuts have been made, without any offset, provided, however, that the interior measurements are multiples of 5 cm. The present invention also relates to a distribution duct having a substantially parallelepipedal cross section, said panel being made from at least one insulating panel according to the invention. Said duct preferably has a main longitudinal axis P and at least one change of direction at an angle P, altering the main longitudinal axis P into a downstream axis P', P", said angle (3 being substantially between 30° and 60° and preferably substantially equal to 45°. The present invention also relates to a method for manufacturing a distribution duct with a substantially parallelepipedal cross section using at least one insulating panel according to the invention. According to this manufacturing method, said duct has a main longitudinal axis P and at least one change of direction at an angle p, altering the main longitudinal axis P into a downstream axis P', P", said angle P being substantially between 30° and 60° and preferably substantially equal to 45°. The method according to the invention thus makes it possible to produce a number of configurations with a significant reduction in head losses by comparison with the configurations of the prior art. Within the meaning of the present invention, "configuration" is used for any non-straight duct resulting from a change in direction of its main axis with or without division of the air flow (for example: elbow with an angle greater than 90° or equal to 90°, inflection, single branch at a right angle with or without a change in cross section of the main duct, double branch at right angles, etc.). A branch is the name given to a configuration that branches the air flow flowing through the network, altering the direction of part of the circulating flow (single or "y" branch) or altering the direction of all the circulating flow (double or "breeches" branch). To ensure adequate distribution, the upstream branch of a branch piece is always the one with the largest cross section. Within the meaning of the present invention, "transverse direction" means a direction oriented at right angles to the overall longitudinal direction of the duct. According to a first alternative form of embodiment of the invention, said change in direction is achieved by cutting each of the faces of said duct from a flat panel. In this first alternative form, the faces of the duct that are parallel to the plane containing said change in direction each have more than four sides in this plane and preferably have six sides or eight sides. According to a second alternative form of embodiment of the invention, said change in direction is achieved by completely sectioning a duct into a primary downstream portion and possibly a secondary downstream portion, and possibly rotating said primary portion or the secondary portion about its main axis. According to this second alternative form of the invention, said sectioning is preferably performed on two faces parallel to the plane containing said change in direction at an angle ß, with respect to a transverse direction of these faces, and on the other two faces, in a transverse direction of these faces. The cutting according to the first alternative form or the sectioning according to the second alternative form is preferably performed using a cutting instrument having two blades situated in the same plane, the cutting edges of the respective blades being directed at opposing inclinations and the first cutting edge being shorter in height than the second cutting edge in the overall cutting or sectioning direction. With the earlier method of construction, to manufacture a configuration (elbow, fork, etc.), openings were made in the face of the panel that remained inside the duct (because that was the only way to bend it to the desired curvature). The interior of the duct therefore had irregularities, even if these faces were covered with a strip. These irregularities subjected the air passing through the duct to numerous changes in direction, creating turbulence and therefore giving rise to head losses. Advantageously, the method according to the invention makes it possible to eliminate these irregularities and therefore to reduce the head losses down the duct. Furthermore, it makes it possible to avoid dust, dirt, etc. produced by these irregularities from being deposited. Advantageously also, the method according to the invention gives better rigidity to the configurations than the earlier method, because it uses, from its start point, a straight duct, the strongest part of the network. Advantageously finally, the method according to the invention makes it possible to significantly reduce the number of offcuts of insulating material used, and the total area of these offcuts, thus making upkeep of the site easier and allowing savings on material. The present invention also relates to a cutting instrument for cutting at least one insulating panel according to the invention, this instrument having two blades situated in the same plane, the cutting edges of the respective blades being directed at opposing inclinations and the first cutting edge being shorter in height than the second cutting edge in the overall cutting direction. In an alternative form, said blades are directed at an angle 5 with respect to a guide surface. In a preferred version ? = d. As a preference, the first cutting edge has a height shorter than the total thickness of the panel and the second cutting edge has a height greater than the total thickness of the panel. The cutting instrument according to the invention gives a clean and precise cut, at the inclination suited to the formation of the configurations, hence giving a perfect join between the cut pieces that make up the configurations. These pieces remain closely assembled using adhesive, giving a perfect join equivalent to that using two straight sections. The present invention will be better understood from studying the detailed description below of some non- limiting exemplary embodiments and the attached figures: • Figure 1 illustrates a profile view of a straight tubular duct for producing a change in direction at an angle ß; • Figure 2 illustrates a profile view of a tubular duct of figure 1 after the change in direction at the angle p has been produced; • Figure 3 is a table illustrating the differences in head loss between the changes in direction produced according to the method of prior art and according to the method of the invention for two types of duct section: 30 x 30 cm and 39 x 32 cm; • Figure 4 illustrates a front view of a marked panel ready to be cut to produce two changes in direction in order to achieve a change in direction at right angles according to the first alternative form of the method according to the invention; • Figure 5 illustrates a front view of a panel ready to be marked out and cut to produce two changes in direction to achieve a change in direction at right angles according to the second alternative form of the method according to the invention; • Figure 6 illustrates a perspective view of a panel according to the invention for producing a tubular duct; • Figures 7, 8 and 9 illustrate the production of a tubular duct from the panel of figure 6 bent at right angles along four longitudinal edges, figure 9 being a view of the detail of figure 8; • Figure 10 is a perspective view of the operation of cutting a tubular duct to produce a change in direction according to the second alternative form of the method according to the invention; • Figure 11 illustrates a view in cross section of a panel while work is being done on the exterior edge of the panel using a cutting instrument according to the invention; • Figure 12 illustrates a view in cross section of a panel while work is being done on the lower edge of the panel using a cutting instrument according to the invention; • Figure 13 illustrates a partial perspective view of a tubular duct before work is done on the edge of the panel using a cutting instrument according to the invention; • Figure 14 illustrates a front view of a first version of the cutting instrument according to the invention with straight blades, and figure 15 illustrates a front view of a second version of the cutting instrument according to the invention, with inclined blades; • Figures 16 to 18 illustrate the production of a change in direction at an angle a, the supplementary angle of the angle ß, not a right angle, in a tubular duct according to the second alternative form of the method according to the invention; • Figures 19 to 21 illustrate the production of a change in direction at an angle a, the supplementary angle of the angle ß, a right angle, in a tubular duct according to the second alternative form of the method according to the invention, figure 21 being supplemented by a table explaining the separations D1 between the main duct and the secondary portion as a function of the minimum length A1 of the primary portion; • Figures 22 to 25 illustrate the production of a change in direction achieving a deviation without a change in the overall orientation of a tubular duct according to the second alternative form of embodiment of the method according to the invention, figure 25 being supplemented by a table explaining the separations D2 between the main duct and the secondary portion as a function of the minimum length A2 of the primary portion; • Figures 26 to 28 illustrate the production of a change in direction achieving a simple branch at a right angle a in a tubular duct according to the second alternative form of embodiment of the method according to the invention, without a change in the cross section of the main duct; • Figures 29 to 34 illustrate the production of a change in direction achieving a simple branch at a right angle a in a tubular duct according to the second alternative form of embodiment of the method according to the invention, with a reduction in the cross section of the main duct; and • Figures 35 to 41 illustrate the production of a change in direction achieving a double branch at two right angles a in a tubular duct according to the second alternative form of embodiment of the method according to the invention. It is emphasized that, in order to make them easier to understand, the figures are not drawn strictly to scale. It is also emphasized that the directions front-rear are to be understood with respect to the direction in which the air flows, considering that the duct is manufactured starting from the source of the air flow. The present invention relates to the production of conditioned-air distribution ducts (1) of substantially parallelepipedal cross section, like the one illustrated in figures 1 and 2, using at least one insulating panel (2) comprising at least one insulating layer (3) of mineral wool, and preferably of rock wool, said duct (1) having a main longitudinal axis P. The insulating duct (1) is intended to convey a conditioned-air flow F, the upstream side of the duct being connected to at least one conditioned-air source (not illustrated) and the downstream side of the duct being connected to at least one conditioned-air distribution outlet (also not illustrated). The air flow F is oriented substantially along the main axis P. The minimum conditions for manufacturing and assembling tubular duct systems with glass wool core for the forced circulation of air at negative or positive pressure ranging up to 500 Pa and maximum speeds of 10 m/s are defined in a standard. The CLIMAVER PLUS and SISTEMA CLIMAVER METAL ducts made by SAINT GOBAIN ISOVER are suited to the implementation of the present invention and meet the standard because they allow pressures ranging up to 800 Pa and maximum speeds of 18 m/s. The duct (1), which is intended to be placed in a metal duct (not illustrated) to form a duct for transporting conditioned air, will be described in greater detail below. The present invention relates more particularly to a method of producing a configuration of duct, so as to achieve at least one change in direction at an angle a or its supplementary angle ß, altering the main longitudinal axis P to a downstream primary axis P' or to a secondary downstream axis P", that is to say involving a single change in direction or a change in direction with a split of the air flow. This is needed because, when installing conditioned-air conveying ducts in a building, only in very exceptional circumstances can the duct be perfectly straight along its entire length, with no change in direction either relative to the horizontal or relative to the vertical between the conditioned-air source and the discharge opening; in the vast majority of cases, manufacture in a building of a duct for transporting and distributing conditioned air dictates changes in direction of the duct and therefore in its insulation, so that the air can be distributed to various contiguous rooms and to rooms on different floors. In the prior art, it is explained that, in order to achieve a change in direction in a distribution duct, it is preferable to break this change in direction down into a great many straight sections arranged in such a way that their respective main axes are separated from the one before and the one after by just a few degrees. In this way, it was thought that the air flow passing along inside the duct would then suffer the least possible modification to its intrinsic properties. Now, it has surprisingly been found that the opposite is in fact true: to alter the intrinsic properties of the air flow passing along inside the duct as little as possible it is preferable for the change in direction to be broken down into the smallest possible number of straight sections and for these sections to be arranged in such a way that their respective main axes are separated from the one before and from the one after by the largest possible angle. However, right angles and acute angles (angles smaller than 90°) are to be forbidden. Thus, according to the invention, said angle (3 is substantially between 30° and 60° and preferably substantially equal to 45°. By way of example, when the head losses in a right- angled elbow of 30 x 30 cm cross section are 8 Pa for a duct manufactured according to the method of the prior art with an air speed of 7 m/s, they are just 5 Pa for a duct manufactured according to the method of the present invention with the same cross section and the same air speed. Figure 3 illustrates the measurements of head loss (in Pa) taken on four types of right-angled elbow (Tl to T4) of square cross section 30 x 30 cm for Tl and T2 and of rectangular cross section 39 x 32 cm for T3 and T4 as a function of the speed of the air flow (in m/s), Tl and T3 being produced using the method of the prior art and T2 and T4 being manufactured according to the method of the present invention. This figure shows that the head losses in an elbow of given cross section manufactured using the method of the present invention (curve T2 in broken line and open circles; curve T4 in broken line and open squares) are lower than those of the elbow with the same given cross section manufactured using the method of the prior art (curve T1 in continuous line, solid triangles; curve T3 in continuous line, solid diamonds), irrespective of the speed of the flow inside the elbow. The method according to the invention makes it possible to eliminate the irregularities formed at the interior surface of the duct when a configuration is produced using the method of the prior and thus makes it possible to reduce the head losses through the duct which would otherwise be generated by these irregularities. Manufacture of the various configurations of duct network begins with the marking-out, on the panel, of the various pieces that will then be cut out and assembled using a small number of lightweight and easy- to-handle tools. The method for manufacturing the configurations according to the invention has two alternative forms of embodiment and of use of the panel (2) according to the invention. In the first alternative form of embodiment of the method according to the invention, said change in direction C is achieved by cutting each of the faces of said duct (1) from a flat panel (2) like the one illustrated in figure 4. In this first alternative form, the faces of the duct which are parallel to the plane containing said change in direction C each have more than four sides in this plane, and preferably have six sides for a single change in direction or eight sides for a double change in direction allowing, ultimately, the direction to be changed through a right angle. In this way, the insulation is even better sealed at the direction change. In the second alternative form of embodiment, the change in direction C is achieved by completely sectioning, that is to say cutting right through, an upstream duct (1) dividing it into a downstream primary portion (1') and possibly a downstream secondary portion (1") if the change in direction is a double one and, also, possibly rotating the primary portion (1') or the secondary portion (1") about its axis. The duct (1-1'-1") is made from a panel (2) like the one illustrated in figure 5. It should be noted that the first alternative form of the method according to the invention produces about 1.5 m2 of off cuts to manufacture two 90° elbows of 30 x 35 cm (approximately), these being illustrated by shading in figure 4, whereas the second alternative form produces no offcuts to manufacture the same two configurations. Figures 1 and 2 schematically depict this second alternative form of embodiment of the method using a straight portion to obtain a change in direction through an angle a. According to this embodiment, the starting point is a tubular duct (1) of rectangular cross section, on four of faces of which four straight marks (20, 20', 20", 20'') are made, in the traditional way, and taking suitable measurements, on the four faces of the duct, which straight marks, in the case of the lines or marks (20, 20") make an angle ß with respect to a transverse line of the face in question at the corner of the duct and which, in the case of the lines (20', 20'") are parallel to said transverse line on the face concerned. The angle ß is the supplementary angle of a, that is to say that a + ß = 180°. The cuts along the marking lines (20', 20"') are made at right angles to the relevant face of the duct, but the cuts along the marking lines (20, 20") are made at an angle ? = 90° - ß. These cuts make it possible to produce a downstream primary duct portion (1') in the tubular duct (1). To obtain the duct (1-1') elbowed at an angle a as illustrated in figure 2, all that is required is for the primary portion (1') to be turned through 180° and the rear edges of the downstream primary portion (1') to be positioned against the front edges of the upstream tubular duct (1). The duct (1-1') then forms an obtusely angled elbow, in other words an elbow angled at an angle a greater than 90°, to give rise to a change in direction of the air flow F. Figure 6 illustrates a panel (2) for producing the tubular duct (1) according to the first or second alternative form of embodiment of the method according to the invention. This panel (2) comprises at least one insulating layer (3) made of mineral wool and preferably of rock wool and has a substantially parallelepipedal and flat shape. It also comprises an exterior layer (4), which will be on the outside of the tubular insulating duct (1) when the latter is formed, and possibly an interior layer (4'), which will be on the inside of the tubular duct (1) when the latter has been formed. The exterior layer (4) is intended to be brought substantially into contact with the metal wall of conditioned-air transport duct. The exterior layer (4) has, on its exterior face, a plurality of marks (5) that are straight and oblique with respect to the longitudinal edges (8) of said panel, said marks forming two sets of lines, one set being inclined at an angle ? = 90° - ß with respect to said longitudinal edges (8) and the other set being oriented at an opposite angle of -? with respect to said longitudinal edges (8). The exterior layer (4) also has a plurality of transverse straight marks (6) oriented at right angles to said transverse edges (9) and a plurality of longitudinal straight marks (7) oriented in the direction of the longitudinal edges (8). The straight marks (5, 6, 7) thus allow the sheet (2), and therefore the tubular body (1) to be sized, so as to make it easier to facilitate the marking-out prior to cutting and the cutting. These marks (5, 6, 7) are therefore used both to facilitate the marking-out and to facilitate the movement of the cutting tool when making the cuts. The marks (5) have been illustrated on just one face of the duct (1) in figure 2 to make this figure easier to read, but they are obviously present on all the faces of the duct (1). Figures 7, 8 and 9 illustrate an exemplary embodiment of a duct (1) made from a single sheet (4) bent along four longitudinal edges at right angles, according to the second alternative form of embodiment of the method according to the invention. As can be seen in figure 7, the four pieces of the panel that are intended to form the faces of the duct each have a straight longitudinal edge and an opposite longitudinal edge shaped as a step, in other words rebated with a rebate of a depth equal to the edge face of the piece it will accommodate after the bending at 90°, and of a thickness equal to half the thickness of said edge face. One of the pieces also has an extension of the exterior layer that will be clipped over the top of the other piece, as can be seen in figure 9. For certain panels, sealing is done using a strip of fabric impregnated with plaster and adhesive or using a self-adhesive aluminum tape. The ducts are particularly well sealed, air leaks to the outside of the duct being negligible provided that this has been manufactured and assembled correctly. The transverse connecting of elements to form the network of ducts is done by placing the surfaces of two duct portions in the same plane, clipping the rebate of one of the portions to the (unrebated) other one, and sealing the coupling using a self-adhesive tape. The transverse edges (9) of the elements for connection are shaped to form a "male" section and a "female" section. At these transverse edges, the density of the glass wool is far higher, and this increases the rigidity of the connection and improves the assembly. The cutting of the panels (2), either in the flat state or once formed into a duct, can be done using a circular saw connected to an extraction system. The circular saw will be provided with a device allowing the cutting angle to be inclined, so as to allow cuts to be made at right angles, at 22.5° with respect to the vertical and at 45°, or even at other angles. In a preferred form of the invention, the panels (2) are cut, either in the flat state, or once formed into a duct, using a special cutting instrument (10) illustrated first of all in figure 10 in respect of the implementation of the second alternative form of the invention. This instrument (10), illustrated in detail in figures 11 to 15, has a guide surface (12) intended to slide along the surface of the panel (2), a handle (14) and two blades (15, 16) situated in the same plane and each having a cutting edge (17, 18) . These cutting edges (17, 18) are oriented in this plane at opposite inclinations with respect to the guide surface (12). The first cutting edge (17), that of the first blade (15), is oriented backwards with regard to the direction of cutting and is shorter in height than the second cutting edge (18), that of the second blade (16), which is oriented forwards; however, the two blades (15, 16) do not touch. The first cutting edge (17) is shorter in height than the total thickness of the panel (2) and the second cutting edge (18) has a height greater than the total thickness of the panel (2). Thus, as can be seen in figure 11, when cutting begins, when the first blade (15) is about to cut into the exterior surface (7), it will cause this surface to be pushed in towards the core of the panel before correctly cutting this surface, and as can be seen in figure 12, when the second blade (16) then goes to cut into the interior surface (4') it too will push this surface in toward the core of the panel before correctly cutting this surface. No delamination can therefore occur when cutting the panel, because the angle of attack of the cutting edges is always acute, on each side of the panel. The instrument (10) according to the invention also allows the cutting of a panel (12), even when this panel is already made into a duct, as can be seen in figure 13. By virtue of the arrangement of the blades 15, 16) and of their respective cutting edges (17, 18), it is possible to begin to cut a duct at a corner without causing any burring or delamination. In a first version of the invention, illustrated in figure 14, the cutting instrument (10) has straight blades (15, 16), that is to say blades oriented at right angles to the guide surface (12) . This version makes it possible to make straight cuts, such as the cuts (20 and 20") in figures 1 and 2. In a second version of the invention, illustrated in figure 15, the cutting instrument (10) has inclined blades (15, 16), that is to say blades oriented at an angle 5 with respect to the guide surface (12) . This version makes it possible to make inclined cuts, such as the cuts (20' and 20"') in figures 1 and 2. In this case, ? = d. It is possible to anticipate for the blades (15, 16) to be equipped with a system allowing their inclination with respect to the guide surface (12) to be adjusted or for the blades (15, 16) to be removable and to collaborate with a rail formed in the guide surface (12), a plurality of rail types dictating different blade inclinations. The constructions of the changes in direction using the second alternative form of the method according to the invention will be described hereinafter. However, the making of changes in the direction (elbows or any other type of configuration) characterized by pure (circular) curves will be avoided, given that these require even more cuts of the interior coating of the duct, thus weakening the configuration and possibly damaging the glass wool if the cut is not executed correctly. a. Elbows at angles a greater than 90° (figures 16 to 18) . To produce an elbow at an angle a greater than 90°, the cutting line is marked on the exterior surface (4) of the duct (1) using the marks (5), as illustrated in figure 16, and the cut is made using a tangential circular saw, or preferably using the instrument (10), along the imaginary plane passing through the duct at right angles to the main axis P and passing through this cutting line. Cuts inclined at P° are preferably made first, before those perpendicular to the surface (4) of the duct. As can be seen in figure 17, the duct is turned on itself through 180° and then positioned so that its axis P' intersects the axis P of the upstream duct, as can be seen in figure 18. As it is not possible to produce a male-female nested joint or to use rebates to clip together the two parts that make up the elbow, a bead of adhesive is applied along the edges that are to be connected, this being done in proximity to the lower edge of the duct. The connecting region is then sealed, on the outside and around the periphery, using a self-adhesive aluminum tape. The tape will maintain the shape and rigidity of the connection, both inside and out. To reduce head losses, it is advisable to provide deflectors in elbows with an angle a of less than 135°. The sheet that holds the deflectors or fins in place inside the duct will be secured using self-tapping screws and washers fitted from the outside. b. Elbows at angles a of 90° (figures 19 to 21) To produce an elbow at an angle a of 90°. An angle of 22.5° with respect to an imaginary perpendicular section is marked on the exterior surface (4) of the duct (1) as illustrated in figure 19, and a line is drawn. The same line is then drawn on the opposite face and these two lines are joined by transverse lines drawn across the two remaining faces. The exterior surface (4) of the panel comprises a template made of marks (5) making it easier to draw the lines that will act as cutting lines. A tangential circular saw or preferably the instrument (10) is used to cut the duct along the lines, paying particular attention to the inclination of the cut (perpendicular to the surface of the duct in the case of the lines at an angle of 22.5° and inclined by 22.5° in the case of the transverse lines) . This then gives the first of the three pieces that will form the elbow: the main duct (1). At a distance of more than 15 cm away from the first sectioning operation, the same operation is performed again, but at an angle of -22.5° with respect to an imaginary perpendicular section. This then gives the three duct portions (1, 1', 1"). The intermediate piece of the duct formed by the primary portion (1') is then turned on itself through 180° as illustrated in figure 20, to form the elbow, and the three portions (1, 1', 1"') are connected in such a way that their respective axes (P, P', P") intersect in pairs at the respective connections at a 45° angle as illustrated in figure 21. The angle a between the most upstream axis P and the most downstream axis P" is 90°. Quite particular attention will be paid to the precision with which the 22.5° angle is measured, otherwise elbows of less than 90° (closed elbows) or of more than 90° (open elbows) will be obtained. In this case, there is no need to provide deflectors. The pieces are sealed as explained in the previous section. The table of figure 21 explains the separations D1 between the main duct (1) of the secondary portion (1") as a function of the minimum length A1 of the primary portion (1'). c. Inflections (figures 22 to 25) An inflection is a deviation in the direction of the duct that is sometimes needed to avoid obstacles in the straight path of the duct. The cross section of the duct is kept constant over its entire course. The method for producing an inflection is very similar to the method for producing a 90° elbow. To produce an inflection, a 22.5° angle with respect to an imaginary perpendicular section is marked on the exterior surface (4) of the duct (1) as illustrated in figure 22, and a line is drawn. The same line is then drawn on the opposite face and these two lines are joined by transverse lines drawn on the remaining two faces. The exterior surface (4) of the panel comprises a template made of marks (5) making it easier to draw the straight lines that will act as cutting lines. A tangential circular saw or preferably the instrument (10) is used to cut the duct along the lines, paying particular attention to the inclination of the cut (perpendicular to the surface of the duct in the case of the lines at an angle of 22.5° and inclined by 22.5° in the case of the transverse lines) . This then gives the first of the three pieces that will form the inflection: the main duct (1). At a distance of more than 20 cm away from the first sectioning operation, the same operation is performed again, but at an identical angle of +22.5°. This then gives the three duct portions (1, 1', 1"). The intermediate piece of the duct formed by the primary portion (1') is then turned on itself through 180° as illustrated in figure 23, to form the inflection, and the three portions (1, 1', 1") are connected in such a way that their respective axes (P, P', P") intersect in pairs at angles of 45°, as illustrated in figure 24. The most upstream axis P and the most downstream axis P" are therefore parallel. Quite particular attention will be paid to the precision with which the 22.5° angle is measured, otherwise there will be a loss in parallelism between the most upstream axis P and the most downstream axis P". There is no need in this case to provide the deflectors. The pieces are sealed as explained in the previous section. The table of figure 25 explains the separations D2 between the main duct (1) and the secondary portion (1") as a function of the minimum length A2 of the primary portion (1'). d. Single branches at a right angle a without a change in cross section of the main duct (figures 26 to 28) To produce a single branch at a right angle a without changing the cross section of the main duct, a 45° angle with respect to an imaginary perpendicular section is marked on the exterior surface (4) of the duct (1) as illustrated in figure 26, and a line is drawn. The same line is then drawn on the opposite face and these two lines are joined by transverse lines drawn on the two remaining faces. The exterior surface (4) of the panel comprises a template made of marks (5) making it easier to draw the straight lines that will act as cutting lines. A tangential circular saw or preferably the instrument (10) is used to cut the duct along the lines, paying particular attention to the inclination of the cut (perpendicular to the surface of the duct in the case of the lines at an angle of 45° and inclined by 45° in the case of the transverse lines) . This then gives the first section of the piece that will form the branch. At a distance of more than 5 cm away from the first sectioning operation, the same operation is performed again, but at an angle of 22.5° with respect to an imaginary perpendicular section. This then gives the three duct portions (1, 1', 1"). The final piece of the duct formed by the secondary portion (1") is then turned on itself through 180° as illustrated in figure 27 to form the branch, and the three portions (1, 1', 1") are connected in such a way that their respective axes (P, P', P") intersect in pairs at angles of 45°, as illustrated in figure 28. The angle a between the most upstream axis P and the most downstream axis P" is 90°. Quite particular attention will be paid to the precision with which the 45° and 22.5° angles are measured otherwise branches of less than 90° (closed branches) or of more than 90° (open branches) will be obtained. There is no need in this case to provide deflectors. The parts are sealed as explained in the previous section. e. Simple branches at a right angle a with a change in cross section of the main duct (figures 29 to 34) To produce a simple branch at a right angle a with a change in the cross section of the main duct, use is made of three straight portions. The first portion constitutes the main portion (1), illustrated in figure 30, the second portion constitutes the primary portion (1')* illustrated in figure 29, of width BK, and will also be used to manufacture the secondary portion (1"), and the third portion constitutes the tertiary portion (1"'), also illustrated in figure 29, of width AK. The first step is to draw an imaginary longitudinal line passing through the intersection of the curves of radius r1 = AK and r2 = BK on the exterior surface of the main portion (1) as illustrated in figure 30. The connection between the continuation of the main portion into the tertiary portion and the branch passes through this line. From this line, there is measured off, on one side, the reduced width aK of the tertiary portion (1"') at the intersection, that is transferred onto the tertiary portion (1"') as illustrated in figure 33, and on the exterior surface, on the other side, a straight line inclined by 22.5° with respect to an imaginary perpendicular section is drawn in order thus to obtain the measurement of the reduced width bK of the primary portion (1') that is transferred onto the primary portion (1') as illustrated in figure 31 as a straight line inclined by 22.5° with respect to an imaginary perpendicular section. Once the measurement aK and bK have been transferred across, the interior points are joined by two straight lines inclined at 45° as far as the longitudinal ends of the portions. On the primary portion (1'), at a distance of more than 15 cm away from the first sectioning operation, the second sectioning operation is performed at an angle of 22.5° with respect to an imaginary perpendicular section, to form the second portion (1"), the primary portion having then to be turned through 180° on itself, as for a right-angled elbow (cf. point b). On the primary portion (1'), the measured value bK of this segment needs to be transferred onto the main duct (1) illustrated in figure 32, then the width bK needs to be transferred, on a straight line inclined at 22.5°, with respect to a transverse line of the main duct (1). To form the branch, the four portions (1, 1', 1", 1"') are connected in such a way that the respective axes (P, P', P") of the portions (1, 1', 1") intersect in pairs at an angle of 45° and that the axes of the main portion (1) and of the tertiary portion (1"') are parallel, as illustrated in figure 34. The angle a between the most upstream axis P and the most downstream axis P" of the branch is 90°. Quite particular attention will be paid to the precision with which the 45° and 22.5° angles are measured, otherwise a branch of less than 90° (closed branch) or of more than 90° (open branch) will be obtained. The is no need in this case to provide deflectors. The pieces are sealed as explained in the previous sections. f. Double branches at two right angles a (figures 35 to 41) The elbows of the branches in this figure, commonly known as a "breeches" connection, are produced as described in section b above. Each branch (left, right) is thus formed of a primary portion (1') and of a secondary portion (1"), the left and right secondary portions (1") coming respectively from the left and right primary portions (1'). The two 90° elbows (left, right) may have different downstream cross sections, the sum of which is greater than the cross section of the main duct, their height having nonetheless to be identical to that of the main portion. The first step consists in drawing a longitudinal line passing through the intersection of the curves of radius r1 = AL and r2 = BL, as illustrated in figure 36, AL and BL representing the respective widths of the interior cross sections of the left and right branches, as illustrated in figure 35. The connection of the two branches passes through this line. From this line, there is drawn, on each side, two straight lines inclined by 22.5° in order thus to obtain the measurements aL and bL that are transferred onto the branches, as illustrated in figure 39. Once the measurements aL and bL have been transferred across on two straight lines inclined by 22.5° on each branch, the interior points are joined using two straight lines inclined at 45° as far as the ends of the branches. The difference between the values of these segments needs to be transferred onto the main duct (1), illustrated in figures 37 and 38, and constitutes the separation between the two primary portions (1') inclined at 22.5° and the main duct (1). It will be easy to check that, if the sum of the interior cross sections of the branches is equal to the interior cross section of the main duct, this difference takes the value 0, and the edges of the pieces need merely to be cut at 45° in the region of connection of the branches. It is advisable for this cut to be made first, before the cuts corresponding to aL and bL. As before, it is of course necessary to surround the exterior part of the connections with self-adhesive tape and to bond the interior part of the connections of the duct. WE CLAIM: 1. An insulating panel (2) for a conditioned-air distribution duct (1), said insulating panel (2) comprising at least one insulating core (3) based on mineral wool, preferably on rock wool, and possibly comprising an exterior layer (4) for example based on a thin skin of aluminum, characterized in that on one exterior face it has a plurality of marks (5) that are straight and oblique with respect to a longitudinal direction of said panel, said marks forming two sets of opposing inclinations oriented at an angle J with respect to said longitudinal direction. 2. The insulating panel (2) as claimed in the preceding claims, wherein said angle 7 is substantially between 82.5° and 52.5° and preferably substantially equal to 67.5°. 3. The insulating panel (2) as claimed in either of the preceding claims, wherein said exterior face also has a plurality of transverse straight marks (6) oriented at right angles to said longitudinal direction. 4. The insulating panel (2) as claimed in any one of the preceding claims, wherein said exterior face also has a plurality of longitudinal straight marks (7) oriented parallel to said longitudinal direction. 5. The insulation panel (2) as claimed in any one of the preceding claims, wherein said oblique straight marks (5), and possibly said transverse straight marks (6) and/or said longitudinal straight marks (7) are embodied at least near the longitudinal edges and preferably across the entire surface of the exterior face. 6. The insulating panel (2) as claimed in any one of the preceding claims, wherein said oblique straight marks (5), and possibly said transverse straight marks (6) and/or said longitudinal straight marks (7) are embodied on the surface of the exterior face of the exterior layer (4). 7. The insulating panel (2) as claimed in any one of the preceding claims wherein said transverse straight marks (6) and/or said longituidinal straight marks(7) intersect said oblique straight marks (5) at points where longitudinal straight marks (7) of opposing inclination intersect. 8. A distribution duct (1) having a substantially parallelepipedal cross section, the duct being made from at least one insulating panel (2) as claimed in any one of the preceding claims. 9. The distribition duct (1) as claimed in the preceding claim, wherein said duct (1) has a main longitudinal axis P and at least one change of direction C at an angle ß, altering the main longitudinal axis P into a downstream axis P', ?', said angle ß being substantially between 30° and 60° and preferably substantially equal to 45°. 10. A method for manufacturing a distribution duct (1) with a substantially parallelepipedal cross section using at least one insulating panel (2) as claimed in any one of claims 1 to 7. 11. The manufacturing method as claimed in the preceding claim, wherein said duct (1) having a main longitudinal axis P and at least one change of direction C at an angle ß, altering the main longitudinal axis P into a downstream axis P', P", said angle ß being substantially between 30° and 60° and preferably substantially equal to 45°. 12.The manufacturing method as claimed in claim 11, wherein said change in direction C is achieved by cutting each of the faces of said duct from a flat panel (2). 13. The manufacturing method as claimed in the preceeding claim, wherein the faces of the duct that are parallel to the plane containing said change in direction C each have more than four sides in this plane and preferably have six sides or eight sides. 14. The manufacturing method as claimed in claim 11, wherein said change in direction C is achieved by completely sectioning a duct (1) into a primary portion (1') and possibly a secondary portion(1"), and possibly rotating said primary portion (1') or said secondary portion (1") about its main axis. 15. The manufacturing method as claimed in the preceding claim, wherein said sectioning is performed on two faces parallel to the plane containing said change In direction C at the angle 0, measured with respect to a transverse direction of these faces, and on the other two faces in a transverse direction of these faces. 16. The manufacturing method as claimed in any one of claims 10 to 15, wherein said cutting or said sectioning is performed using a cutting instrument (10) having two blades (15, 16) situated in the same plane, the cutting edges (17,18) of the respective blades (15,16) being directed at opposing inclinations and the First cutting edge (17) being shorter in height than the second cutting edge (18) in the overall cutting or sectioning direction. 17. The manufacturing method as claimed in claim 16, wherein said cutting instrument (10) has blades (15,16) directed at an angle 5 with respect to a guide surface (2). 18. The manufacturing method as claimed in claim 17, wherein ? =d. 19. The manufacturing method as claimed in claim 16, wherein said cutting instrument has a first cutting edge (17) and a height shorter than the total thickness of the panel (2) and the second cutting edge (18) has a height greater than the total thickness of the panel (2). An insulating panel (2) for a conditioned-air distribution duct (1), said insulating panel (2) comprising at least one insulating core (3) based on mineral wool, preferably on rock wool, and possibly comprising an exterior layer (4) for example based on a thin skin of aluminium, characterized in that on one exterior face it has a plurality of marks (5) that are straight and oblique with respect to a longitudinal direction of said panel, said marks forming two sets of opposing inclinations oriented at an angle γ with respect to said longitudinal direction.

Full Text

The present invention relates to an insulating panel
for a duct for distributing conditioned air, said
insulating panel comprising at least one insulating
core based on mineral wool, preferably on rock wool,
and possibly comprising an exterior layer for example
based on a thin skin of aluminum.
The present invention relates more specifically to the
manufacture, in buildings, of ducts for transporting
and distributing conditioned air. Such ducts generally
have a metal structure made up of a self-supporting
framework and of metal sheets arranged between the
members of this framework, and on the inside of this
duct, insulation made from insulating panels. The
manufacture of these ducts for transporting and
distributing conditioned air entails the incorporation
of changes in direction to the duct, so as to
distribute air to various points.
The prior art discloses a method for manufacturing
insulating ducts whereby the direction-change angle is
broken down into a great many angles of smaller
magnitude. Thus, according to that method, the change
in direction is very gradual and the intrinsic
parameters of the air stream are modified only slightly
as the stream gradually progresses through the change
in direction.
The purpose of the invention is to make it possible to
reduce the head losses generated in the changes in
direction produced according to the method of the prior
art, while at the same time making the changes in
direction easier to produce.
The subject of the present invention is therefore an
insulating panel for a duct for distributing
conditioned air according to claim 1.
This insulating panel comprises at least one insulating
core based on mineral wool, preferably on rock wool,
and possibly comprises an exterior layer for example
based on a thin skin of aluminum. This panel also has,
on an exterior face, a plurality of marks that are
straight and oblique with respect to a longitudinal
direction of said panel, said marks forming two sets of
opposing inclinations oriented at an angle ? with
respect to said longitudinal direction.
Said angle y is preferably substantially between 82.5°
and 52.5° and more preferably still is substantially
equal to 67.5°.
Said exterior face of the panel also preferably has a
plurality of transverse straight marks oriented at
right angles to said longitudinal direction and, also
as a preference, a plurality of longitudinal straight
marks oriented parallel to said longitudinal direction.
Said oblique straight marks, and possibly said
transverse straight marks and/or said longitudinal
straight marks are preferably embodied at least near
the longitudinal edges and preferably across the entire
surface of the exterior face.
Said oblique straight marks, and possibly said
transverse straight marks and/or said longitudinal
straight marks are preferably embodied on the surface
of the exterior face of the exterior layer of the
panel.
In an alternative form, said transverse straight marks
and/or said longitudinal straight marks intersect said
oblique straight marks at points where longitudinal
straight marks of opposing inclination intersect.
The oblique, transverse and straight guide marks- thus
make insulating ducts easier to manufacture and allow a
saving in time and an increase in accuracy when marking
out and cutting on site.
The marks are designed to coincide on the four faces of
the duct once the necessary cuts have been made,
without any offset, provided, however, that the
interior measurements are multiples of 5 cm.
The present invention also relates to a distribution
duct having a substantially parallelepipedal cross
section, said panel being made from at least one
insulating panel according to the invention.
Said duct preferably has a main longitudinal axis P and
at least one change of direction at an angle P,
altering the main longitudinal axis P into a downstream
axis P', P", said angle (3 being substantially between
30° and 60° and preferably substantially equal to 45°.
The present invention also relates to a method for
manufacturing a distribution duct with a substantially
parallelepipedal cross section using at least one
insulating panel according to the invention.
According to this manufacturing method, said duct has a
main longitudinal axis P and at least one change of
direction at an angle p, altering the main longitudinal
axis P into a downstream axis P', P", said angle P
being substantially between 30° and 60° and preferably
substantially equal to 45°.
The method according to the invention thus makes it
possible to produce a number of configurations with a
significant reduction in head losses by comparison with
the configurations of the prior art.
Within the meaning of the present invention,
"configuration" is used for any non-straight duct
resulting from a change in direction of its main axis
with or without division of the air flow (for example:
elbow with an angle greater than 90° or equal to 90°,
inflection, single branch at a right angle with or
without a change in cross section of the main duct,
double branch at right angles, etc.).
A branch is the name given to a configuration that
branches the air flow flowing through the network,
altering the direction of part of the circulating flow
(single or "y" branch) or altering the direction of all
the circulating flow (double or "breeches" branch). To
ensure adequate distribution, the upstream branch of a
branch piece is always the one with the largest cross
section.
Within the meaning of the present invention,
"transverse direction" means a direction oriented at
right angles to the overall longitudinal direction of
the duct.
According to a first alternative form of embodiment of
the invention, said change in direction is achieved by
cutting each of the faces of said duct from a flat
panel.
In this first alternative form, the faces of the duct
that are parallel to the plane containing said change
in direction each have more than four sides in this
plane and preferably have six sides or eight sides.
According to a second alternative form of embodiment of
the invention, said change in direction is achieved by
completely sectioning a duct into a primary downstream
portion and possibly a secondary downstream portion,
and possibly rotating said primary portion or the
secondary portion about its main axis.
According to this second alternative form of the
invention, said sectioning is preferably performed on
two faces parallel to the plane containing said change
in direction at an angle ß, with respect to a
transverse direction of these faces, and on the other
two faces, in a transverse direction of these faces.
The cutting according to the first alternative form or
the sectioning according to the second alternative form
is preferably performed using a cutting instrument
having two blades situated in the same plane, the
cutting edges of the respective blades being directed
at opposing inclinations and the first cutting edge
being shorter in height than the second cutting edge in
the overall cutting or sectioning direction.
With the earlier method of construction, to manufacture
a configuration (elbow, fork, etc.), openings were made
in the face of the panel that remained inside the duct
(because that was the only way to bend it to the
desired curvature). The interior of the duct therefore
had irregularities, even if these faces were covered
with a strip. These irregularities subjected the air
passing through the duct to numerous changes in
direction, creating turbulence and therefore giving
rise to head losses.
Advantageously, the method according to the invention
makes it possible to eliminate these irregularities and
therefore to reduce the head losses down the duct.
Furthermore, it makes it possible to avoid dust, dirt,
etc. produced by these irregularities from being
deposited.
Advantageously also, the method according to the
invention gives better rigidity to the configurations
than the earlier method, because it uses, from its
start point, a straight duct, the strongest part of the
network.
Advantageously finally, the method according to the
invention makes it possible to significantly reduce the
number of offcuts of insulating material used, and the
total area of these offcuts, thus making upkeep of the
site easier and allowing savings on material.
The present invention also relates to a cutting
instrument for cutting at least one insulating panel
according to the invention, this instrument having two
blades situated in the same plane, the cutting edges of
the respective blades being directed at opposing
inclinations and the first cutting edge being shorter
in height than the second cutting edge in the overall
cutting direction.
In an alternative form, said blades are directed at an
angle 5 with respect to a guide surface.
In a preferred version ? = d.
As a preference, the first cutting edge has a height
shorter than the total thickness of the panel and the
second cutting edge has a height greater than the total
thickness of the panel.
The cutting instrument according to the invention gives
a clean and precise cut, at the inclination suited to
the formation of the configurations, hence giving a
perfect join between the cut pieces that make up the
configurations. These pieces remain closely assembled
using adhesive, giving a perfect join equivalent to
that using two straight sections.
The present invention will be better understood from
studying the detailed description below of some non-
limiting exemplary embodiments and the attached
figures:
• Figure 1 illustrates a profile view of a straight
tubular duct for producing a change in direction at an
angle ß;
• Figure 2 illustrates a profile view of a tubular
duct of figure 1 after the change in direction at the
angle p has been produced;
• Figure 3 is a table illustrating the differences
in head loss between the changes in direction produced
according to the method of prior art and according to
the method of the invention for two types of duct
section: 30 x 30 cm and 39 x 32 cm;
• Figure 4 illustrates a front view of a marked
panel ready to be cut to produce two changes in
direction in order to achieve a change in direction at
right angles according to the first alternative form of
the method according to the invention;
• Figure 5 illustrates a front view of a panel ready
to be marked out and cut to produce two changes in
direction to achieve a change in direction at right
angles according to the second alternative form of the
method according to the invention;
• Figure 6 illustrates a perspective view of a panel
according to the invention for producing a tubular
duct;
• Figures 7, 8 and 9 illustrate the production of a
tubular duct from the panel of figure 6 bent at right
angles along four longitudinal edges, figure 9 being a
view of the detail of figure 8;
• Figure 10 is a perspective view of the operation
of cutting a tubular duct to produce a change in
direction according to the second alternative form of
the method according to the invention;
• Figure 11 illustrates a view in cross section of a
panel while work is being done on the exterior edge of
the panel using a cutting instrument according to the
invention;
• Figure 12 illustrates a view in cross section of a
panel while work is being done on the lower edge of the
panel using a cutting instrument according to the
invention;
• Figure 13 illustrates a partial perspective view
of a tubular duct before work is done on the edge of
the panel using a cutting instrument according to the
invention;
• Figure 14 illustrates a front view of a first
version of the cutting instrument according to the
invention with straight blades, and figure 15
illustrates a front view of a second version of the
cutting instrument according to the invention, with
inclined blades;
• Figures 16 to 18 illustrate the production of a
change in direction at an angle a, the supplementary
angle of the angle ß, not a right angle, in a tubular
duct according to the second alternative form of the
method according to the invention;
• Figures 19 to 21 illustrate the production of a
change in direction at an angle a, the supplementary
angle of the angle ß, a right angle, in a tubular duct
according to the second alternative form of the method
according to the invention, figure 21 being
supplemented by a table explaining the separations D1
between the main duct and the secondary portion as a
function of the minimum length A1 of the primary
portion;
• Figures 22 to 25 illustrate the production of a
change in direction achieving a deviation without a
change in the overall orientation of a tubular duct
according to the second alternative form of embodiment
of the method according to the invention, figure 25
being supplemented by a table explaining the
separations D2 between the main duct and the secondary
portion as a function of the minimum length A2 of the
primary portion;
• Figures 26 to 28 illustrate the production of a
change in direction achieving a simple branch at a
right angle a in a tubular duct according to the second
alternative form of embodiment of the method according
to the invention, without a change in the cross section
of the main duct;
• Figures 29 to 34 illustrate the production of a
change in direction achieving a simple branch at a
right angle a in a tubular duct according to the second
alternative form of embodiment of the method according
to the invention, with a reduction in the cross section
of the main duct; and
• Figures 35 to 41 illustrate the production of a
change in direction achieving a double branch at two
right angles a in a tubular duct according to the
second alternative form of embodiment of the method
according to the invention.
It is emphasized that, in order to make them easier to
understand, the figures are not drawn strictly to
scale.
It is also emphasized that the directions front-rear
are to be understood with respect to the direction in
which the air flows, considering that the duct is
manufactured starting from the source of the air flow.
The present invention relates to the production of
conditioned-air distribution ducts (1) of substantially
parallelepipedal cross section, like the one
illustrated in figures 1 and 2, using at least one
insulating panel (2) comprising at least one insulating
layer (3) of mineral wool, and preferably of rock wool,
said duct (1) having a main longitudinal axis P. The
insulating duct (1) is intended to convey a
conditioned-air flow F, the upstream side of the duct
being connected to at least one conditioned-air source
(not illustrated) and the downstream side of the duct
being connected to at least one conditioned-air
distribution outlet (also not illustrated). The air
flow F is oriented substantially along the main axis P.
The minimum conditions for manufacturing and assembling
tubular duct systems with glass wool core for the
forced circulation of air at negative or positive
pressure ranging up to 500 Pa and maximum speeds of
10 m/s are defined in a standard. The CLIMAVER PLUS and
SISTEMA CLIMAVER METAL ducts made by SAINT GOBAIN
ISOVER are suited to the implementation of the present
invention and meet the standard because they allow
pressures ranging up to 800 Pa and maximum speeds of
18 m/s. The duct (1), which is intended to be placed in
a metal duct (not illustrated) to form a duct for
transporting conditioned air, will be described in
greater detail below.
The present invention relates more particularly to a
method of producing a configuration of duct, so as to
achieve at least one change in direction at an angle a
or its supplementary angle ß, altering the main
longitudinal axis P to a downstream primary axis P' or
to a secondary downstream axis P", that is to say
involving a single change in direction or a change in
direction with a split of the air flow.
This is needed because, when installing conditioned-air
conveying ducts in a building, only in very exceptional
circumstances can the duct be perfectly straight along
its entire length, with no change in direction either
relative to the horizontal or relative to the vertical
between the conditioned-air source and the discharge
opening; in the vast majority of cases, manufacture in
a building of a duct for transporting and distributing
conditioned air dictates changes in direction of the
duct and therefore in its insulation, so that the air
can be distributed to various contiguous rooms and to
rooms on different floors.
In the prior art, it is explained that, in order to
achieve a change in direction in a distribution duct,
it is preferable to break this change in direction down
into a great many straight sections arranged in such a
way that their respective main axes are separated from
the one before and the one after by just a few degrees.
In this way, it was thought that the air flow passing
along inside the duct would then suffer the least
possible modification to its intrinsic properties.
Now, it has surprisingly been found that the opposite
is in fact true: to alter the intrinsic properties of
the air flow passing along inside the duct as little as
possible it is preferable for the change in direction
to be broken down into the smallest possible number of
straight sections and for these sections to be arranged
in such a way that their respective main axes are
separated from the one before and from the one after by
the largest possible angle. However, right angles and
acute angles (angles smaller than 90°) are to be
forbidden.
Thus, according to the invention, said angle (3 is
substantially between 30° and 60° and preferably
substantially equal to 45°.
By way of example, when the head losses in a right-
angled elbow of 30 x 30 cm cross section are 8 Pa for a
duct manufactured according to the method of the prior
art with an air speed of 7 m/s, they are just 5 Pa for
a duct manufactured according to the method of the
present invention with the same cross section and the
same air speed.
Figure 3 illustrates the measurements of head loss (in
Pa) taken on four types of right-angled elbow (Tl to
T4) of square cross section 30 x 30 cm for Tl and T2
and of rectangular cross section 39 x 32 cm for T3 and
T4 as a function of the speed of the air flow (in m/s),
Tl and T3 being produced using the method of the prior
art and T2 and T4 being manufactured according to the
method of the present invention.
This figure shows that the head losses in an elbow of
given cross section manufactured using the method of
the present invention (curve T2 in broken line and open
circles; curve T4 in broken line and open squares) are
lower than those of the elbow with the same given cross
section manufactured using the method of the prior art
(curve T1 in continuous line, solid triangles; curve T3
in continuous line, solid diamonds), irrespective of
the speed of the flow inside the elbow.
The method according to the invention makes it possible
to eliminate the irregularities formed at the interior
surface of the duct when a configuration is produced
using the method of the prior and thus makes it
possible to reduce the head losses through the duct
which would otherwise be generated by these
irregularities.
Manufacture of the various configurations of duct
network begins with the marking-out, on the panel, of
the various pieces that will then be cut out and
assembled using a small number of lightweight and easy-
to-handle tools.
The method for manufacturing the configurations
according to the invention has two alternative forms of
embodiment and of use of the panel (2) according to the
invention.
In the first alternative form of embodiment of the
method according to the invention, said change in
direction C is achieved by cutting each of the faces of
said duct (1) from a flat panel (2) like the one
illustrated in figure 4.
In this first alternative form, the faces of the duct
which are parallel to the plane containing said change
in direction C each have more than four sides in this
plane, and preferably have six sides for a single
change in direction or eight sides for a double change
in direction allowing, ultimately, the direction to be
changed through a right angle. In this way, the
insulation is even better sealed at the direction
change.
In the second alternative form of embodiment, the
change in direction C is achieved by completely
sectioning, that is to say cutting right through, an
upstream duct (1) dividing it into a downstream primary
portion (1') and possibly a downstream secondary
portion (1") if the change in direction is a double one
and, also, possibly rotating the primary portion (1')
or the secondary portion (1") about its axis. The duct
(1-1'-1") is made from a panel (2) like the one
illustrated in figure 5.
It should be noted that the first alternative form of
the method according to the invention produces about
1.5 m2 of off cuts to manufacture two 90° elbows of
30 x 35 cm (approximately), these being illustrated by
shading in figure 4, whereas the second alternative
form produces no offcuts to manufacture the same two
configurations.
Figures 1 and 2 schematically depict this second
alternative form of embodiment of the method using a
straight portion to obtain a change in direction
through an angle a.
According to this embodiment, the starting point is a
tubular duct (1) of rectangular cross section, on four
of faces of which four straight marks (20, 20', 20",
20'') are made, in the traditional way, and taking
suitable measurements, on the four faces of the duct,
which straight marks, in the case of the lines or marks
(20, 20") make an angle ß with respect to a transverse
line of the face in question at the corner of the duct
and which, in the case of the lines (20', 20'") are
parallel to said transverse line on the face concerned.
The angle ß is the supplementary angle of a, that is to
say that a + ß = 180°.
The cuts along the marking lines (20', 20"') are made
at right angles to the relevant face of the duct, but
the cuts along the marking lines (20, 20") are made at
an angle ? = 90° - ß. These cuts make it possible to
produce a downstream primary duct portion (1') in the
tubular duct (1).
To obtain the duct (1-1') elbowed at an angle a as
illustrated in figure 2, all that is required is for
the primary portion (1') to be turned through 180° and
the rear edges of the downstream primary portion (1')
to be positioned against the front edges of the
upstream tubular duct (1). The duct (1-1') then forms
an obtusely angled elbow, in other words an elbow
angled at an angle a greater than 90°, to give rise to
a change in direction of the air flow F.
Figure 6 illustrates a panel (2) for producing the
tubular duct (1) according to the first or second
alternative form of embodiment of the method according
to the invention.
This panel (2) comprises at least one insulating layer
(3) made of mineral wool and preferably of rock wool
and has a substantially parallelepipedal and flat
shape. It also comprises an exterior layer (4), which
will be on the outside of the tubular insulating duct
(1) when the latter is formed, and possibly an interior
layer (4'), which will be on the inside of the tubular
duct (1) when the latter has been formed. The exterior
layer (4) is intended to be brought substantially into
contact with the metal wall of conditioned-air
transport duct.
The exterior layer (4) has, on its exterior face, a
plurality of marks (5) that are straight and oblique
with respect to the longitudinal edges (8) of said
panel, said marks forming two sets of lines, one set
being inclined at an angle ? = 90° - ß with respect to
said longitudinal edges (8) and the other set being
oriented at an opposite angle of -? with respect to
said longitudinal edges (8).
The exterior layer (4) also has a plurality of
transverse straight marks (6) oriented at right angles
to said transverse edges (9) and a plurality of
longitudinal straight marks (7) oriented in the
direction of the longitudinal edges (8).
The straight marks (5, 6, 7) thus allow the sheet (2),
and therefore the tubular body (1) to be sized, so as
to make it easier to facilitate the marking-out prior
to cutting and the cutting.
These marks (5, 6, 7) are therefore used both to
facilitate the marking-out and to facilitate the
movement of the cutting tool when making the cuts.
The marks (5) have been illustrated on just one face of
the duct (1) in figure 2 to make this figure easier to
read, but they are obviously present on all the faces
of the duct (1).
Figures 7, 8 and 9 illustrate an exemplary embodiment
of a duct (1) made from a single sheet (4) bent along
four longitudinal edges at right angles, according to
the second alternative form of embodiment of the method
according to the invention.
As can be seen in figure 7, the four pieces of the
panel that are intended to form the faces of the duct
each have a straight longitudinal edge and an opposite
longitudinal edge shaped as a step, in other words
rebated with a rebate of a depth equal to the edge face
of the piece it will accommodate after the bending at
90°, and of a thickness equal to half the thickness of
said edge face. One of the pieces also has an extension
of the exterior layer that will be clipped over the top
of the other piece, as can be seen in figure 9.
For certain panels, sealing is done using a strip of
fabric impregnated with plaster and adhesive or using a
self-adhesive aluminum tape.
The ducts are particularly well sealed, air leaks to
the outside of the duct being negligible provided that
this has been manufactured and assembled correctly.
The transverse connecting of elements to form the
network of ducts is done by placing the surfaces of two
duct portions in the same plane, clipping the rebate of
one of the portions to the (unrebated) other one, and
sealing the coupling using a self-adhesive tape. The
transverse edges (9) of the elements for connection are
shaped to form a "male" section and a "female" section.
At these transverse edges, the density of the glass
wool is far higher, and this increases the rigidity of
the connection and improves the assembly.
The cutting of the panels (2), either in the flat state
or once formed into a duct, can be done using a
circular saw connected to an extraction system. The
circular saw will be provided with a device allowing
the cutting angle to be inclined, so as to allow cuts
to be made at right angles, at 22.5° with respect to
the vertical and at 45°, or even at other angles.
In a preferred form of the invention, the panels (2)
are cut, either in the flat state, or once formed into
a duct, using a special cutting instrument (10)
illustrated first of all in figure 10 in respect of the
implementation of the second alternative form of the
invention. This instrument (10), illustrated in detail
in figures 11 to 15, has a guide surface (12) intended
to slide along the surface of the panel (2), a handle
(14) and two blades (15, 16) situated in the same plane
and each having a cutting edge (17, 18) . These cutting
edges (17, 18) are oriented in this plane at opposite
inclinations with respect to the guide surface (12).
The first cutting edge (17), that of the first blade
(15), is oriented backwards with regard to the
direction of cutting and is shorter in height than the
second cutting edge (18), that of the second blade
(16), which is oriented forwards; however, the two
blades (15, 16) do not touch. The first cutting edge
(17) is shorter in height than the total thickness of
the panel (2) and the second cutting edge (18) has a
height greater than the total thickness of the panel
(2).
Thus, as can be seen in figure 11, when cutting begins,
when the first blade (15) is about to cut into the
exterior surface (7), it will cause this surface to be
pushed in towards the core of the panel before
correctly cutting this surface, and as can be seen in
figure 12, when the second blade (16) then goes to cut
into the interior surface (4') it too will push this
surface in toward the core of the panel before
correctly cutting this surface. No delamination can
therefore occur when cutting the panel, because the
angle of attack of the cutting edges is always acute,
on each side of the panel.
The instrument (10) according to the invention also
allows the cutting of a panel (12), even when this
panel is already made into a duct, as can be seen in
figure 13. By virtue of the arrangement of the blades
15, 16) and of their respective cutting edges (17, 18),
it is possible to begin to cut a duct at a corner
without causing any burring or delamination.
In a first version of the invention, illustrated in
figure 14, the cutting instrument (10) has straight
blades (15, 16), that is to say blades oriented at
right angles to the guide surface (12) . This version
makes it possible to make straight cuts, such as the
cuts (20 and 20") in figures 1 and 2.
In a second version of the invention, illustrated in
figure 15, the cutting instrument (10) has inclined
blades (15, 16), that is to say blades oriented at an
angle 5 with respect to the guide surface (12) . This
version makes it possible to make inclined cuts, such
as the cuts (20' and 20"') in figures 1 and 2. In this
case, ? = d.
It is possible to anticipate for the blades (15, 16) to
be equipped with a system allowing their inclination
with respect to the guide surface (12) to be adjusted
or for the blades (15, 16) to be removable and to
collaborate with a rail formed in the guide surface
(12), a plurality of rail types dictating different
blade inclinations.
The constructions of the changes in direction using the
second alternative form of the method according to the
invention will be described hereinafter.
However, the making of changes in the direction (elbows
or any other type of configuration) characterized by
pure (circular) curves will be avoided, given that
these require even more cuts of the interior coating of
the duct, thus weakening the configuration and possibly
damaging the glass wool if the cut is not executed
correctly.
a. Elbows at angles a greater than 90° (figures 16
to 18) .
To produce an elbow at an angle a greater than 90°, the
cutting line is marked on the exterior surface (4) of
the duct (1) using the marks (5), as illustrated in
figure 16, and the cut is made using a tangential
circular saw, or preferably using the instrument (10),
along the imaginary plane passing through the duct at
right angles to the main axis P and passing through
this cutting line. Cuts inclined at P° are preferably
made first, before those perpendicular to the surface
(4) of the duct.
As can be seen in figure 17, the duct is turned on
itself through 180° and then positioned so that its
axis P' intersects the axis P of the upstream duct, as
can be seen in figure 18.
As it is not possible to produce a male-female nested
joint or to use rebates to clip together the two parts
that make up the elbow, a bead of adhesive is applied
along the edges that are to be connected, this being
done in proximity to the lower edge of the duct. The
connecting region is then sealed, on the outside and
around the periphery, using a self-adhesive aluminum
tape. The tape will maintain the shape and rigidity of
the connection, both inside and out.
To reduce head losses, it is advisable to provide
deflectors in elbows with an angle a of less than 135°.
The sheet that holds the deflectors or fins in place
inside the duct will be secured using self-tapping
screws and washers fitted from the outside.
b. Elbows at angles a of 90° (figures 19 to 21)
To produce an elbow at an angle a of 90°. An angle of
22.5° with respect to an imaginary perpendicular
section is marked on the exterior surface (4) of the
duct (1) as illustrated in figure 19, and a line is
drawn. The same line is then drawn on the opposite face
and these two lines are joined by transverse lines
drawn across the two remaining faces.
The exterior surface (4) of the panel comprises a
template made of marks (5) making it easier to draw the
lines that will act as cutting lines.
A tangential circular saw or preferably the instrument
(10) is used to cut the duct along the lines, paying
particular attention to the inclination of the cut
(perpendicular to the surface of the duct in the case
of the lines at an angle of 22.5° and inclined by 22.5°
in the case of the transverse lines) . This then gives
the first of the three pieces that will form the elbow:
the main duct (1).
At a distance of more than 15 cm away from the first
sectioning operation, the same operation is performed
again, but at an angle of -22.5° with respect to an
imaginary perpendicular section. This then gives the
three duct portions (1, 1', 1").
The intermediate piece of the duct formed by the
primary portion (1') is then turned on itself through
180° as illustrated in figure 20, to form the elbow,
and the three portions (1, 1', 1"') are connected in
such a way that their respective axes (P, P', P")
intersect in pairs at the respective connections at a
45° angle as illustrated in figure 21. The angle a
between the most upstream axis P and the most
downstream axis P" is 90°.
Quite particular attention will be paid to the
precision with which the 22.5° angle is measured,
otherwise elbows of less than 90° (closed elbows) or of
more than 90° (open elbows) will be obtained.
In this case, there is no need to provide deflectors.
The pieces are sealed as explained in the previous
section.
The table of figure 21 explains the separations D1
between the main duct (1) of the secondary portion (1")
as a function of the minimum length A1 of the primary
portion (1').
c. Inflections (figures 22 to 25)
An inflection is a deviation in the direction of the
duct that is sometimes needed to avoid obstacles in the
straight path of the duct. The cross section of the
duct is kept constant over its entire course.
The method for producing an inflection is very similar
to the method for producing a 90° elbow.
To produce an inflection, a 22.5° angle with respect to
an imaginary perpendicular section is marked on the
exterior surface (4) of the duct (1) as illustrated in
figure 22, and a line is drawn. The same line is then
drawn on the opposite face and these two lines are
joined by transverse lines drawn on the remaining two
faces.
The exterior surface (4) of the panel comprises a
template made of marks (5) making it easier to draw the
straight lines that will act as cutting lines.
A tangential circular saw or preferably the instrument
(10) is used to cut the duct along the lines, paying
particular attention to the inclination of the cut
(perpendicular to the surface of the duct in the case
of the lines at an angle of 22.5° and inclined by 22.5°
in the case of the transverse lines) . This then gives
the first of the three pieces that will form the
inflection: the main duct (1).
At a distance of more than 20 cm away from the first
sectioning operation, the same operation is performed
again, but at an identical angle of +22.5°. This then
gives the three duct portions (1, 1', 1").
The intermediate piece of the duct formed by the
primary portion (1') is then turned on itself through
180° as illustrated in figure 23, to form the
inflection, and the three portions (1, 1', 1") are
connected in such a way that their respective axes
(P, P', P") intersect in pairs at angles of 45°, as
illustrated in figure 24. The most upstream axis P and
the most downstream axis P" are therefore parallel.
Quite particular attention will be paid to the
precision with which the 22.5° angle is measured,
otherwise there will be a loss in parallelism between
the most upstream axis P and the most downstream axis
P".
There is no need in this case to provide the
deflectors.
The pieces are sealed as explained in the previous
section.
The table of figure 25 explains the separations D2
between the main duct (1) and the secondary portion
(1") as a function of the minimum length A2 of the
primary portion (1').
d. Single branches at a right angle a without a
change in cross section of the main duct
(figures 26 to 28)
To produce a single branch at a right angle a without
changing the cross section of the main duct, a 45°
angle with respect to an imaginary perpendicular
section is marked on the exterior surface (4) of the
duct (1) as illustrated in figure 26, and a line is
drawn. The same line is then drawn on the opposite face
and these two lines are joined by transverse lines
drawn on the two remaining faces.
The exterior surface (4) of the panel comprises a
template made of marks (5) making it easier to draw the
straight lines that will act as cutting lines.
A tangential circular saw or preferably the instrument
(10) is used to cut the duct along the lines, paying
particular attention to the inclination of the cut
(perpendicular to the surface of the duct in the case
of the lines at an angle of 45° and inclined by 45° in
the case of the transverse lines) . This then gives the
first section of the piece that will form the branch.
At a distance of more than 5 cm away from the first
sectioning operation, the same operation is performed
again, but at an angle of 22.5° with respect to an
imaginary perpendicular section. This then gives the
three duct portions (1, 1', 1").
The final piece of the duct formed by the secondary
portion (1") is then turned on itself through 180° as
illustrated in figure 27 to form the branch, and the
three portions (1, 1', 1") are connected in such a way
that their respective axes (P, P', P") intersect in
pairs at angles of 45°, as illustrated in figure 28.
The angle a between the most upstream axis P and the
most downstream axis P" is 90°.
Quite particular attention will be paid to the
precision with which the 45° and 22.5° angles are
measured otherwise branches of less than 90° (closed
branches) or of more than 90° (open branches) will be
obtained.
There is no need in this case to provide deflectors.
The parts are sealed as explained in the previous
section.
e. Simple branches at a right angle a with a
change in cross section of the main duct
(figures 29 to 34)
To produce a simple branch at a right angle a with a
change in the cross section of the main duct, use is
made of three straight portions. The first portion
constitutes the main portion (1), illustrated in figure
30, the second portion constitutes the primary portion
(1')* illustrated in figure 29, of width BK, and will
also be used to manufacture the secondary portion (1"),
and the third portion constitutes the tertiary portion
(1"'), also illustrated in figure 29, of width AK.
The first step is to draw an imaginary longitudinal
line passing through the intersection of the curves of
radius r1 = AK and r2 = BK on the exterior surface of
the main portion (1) as illustrated in figure 30. The
connection between the continuation of the main portion
into the tertiary portion and the branch passes through
this line.
From this line, there is measured off, on one side, the
reduced width aK of the tertiary portion (1"') at the
intersection, that is transferred onto the tertiary
portion (1"') as illustrated in figure 33, and on the
exterior surface, on the other side, a straight line
inclined by 22.5° with respect to an imaginary
perpendicular section is drawn in order thus to obtain
the measurement of the reduced width bK of the primary
portion (1') that is transferred onto the primary
portion (1') as illustrated in figure 31 as a straight
line inclined by 22.5° with respect to an imaginary
perpendicular section.
Once the measurement aK and bK have been transferred
across, the interior points are joined by two straight
lines inclined at 45° as far as the longitudinal ends
of the portions.
On the primary portion (1'), at a distance of more than
15 cm away from the first sectioning operation, the
second sectioning operation is performed at an angle of
22.5° with respect to an imaginary perpendicular
section, to form the second portion (1"), the primary
portion having then to be turned through 180° on
itself, as for a right-angled elbow (cf. point b).
On the primary portion (1'), the measured value bK of
this segment needs to be transferred onto the main duct
(1) illustrated in figure 32, then the width bK needs
to be transferred, on a straight line inclined at
22.5°, with respect to a transverse line of the main
duct (1).
To form the branch, the four portions (1, 1', 1", 1"')
are connected in such a way that the respective axes
(P, P', P") of the portions (1, 1', 1") intersect in
pairs at an angle of 45° and that the axes of the main
portion (1) and of the tertiary portion (1"') are
parallel, as illustrated in figure 34. The angle a
between the most upstream axis P and the most
downstream axis P" of the branch is 90°.
Quite particular attention will be paid to the
precision with which the 45° and 22.5° angles are
measured, otherwise a branch of less than 90° (closed
branch) or of more than 90° (open branch) will be
obtained.
The is no need in this case to provide deflectors.
The pieces are sealed as explained in the previous
sections.
f. Double branches at two right angles a (figures
35 to 41)
The elbows of the branches in this figure, commonly
known as a "breeches" connection, are produced as
described in section b above. Each branch (left, right)
is thus formed of a primary portion (1') and of a
secondary portion (1"), the left and right secondary
portions (1") coming respectively from the left and
right primary portions (1'). The two 90° elbows (left,
right) may have different downstream cross sections,
the sum of which is greater than the cross section of
the main duct, their height having nonetheless to be
identical to that of the main portion.
The first step consists in drawing a longitudinal line
passing through the intersection of the curves of
radius r1 = AL and r2 = BL, as illustrated in figure 36,
AL and BL representing the respective widths of the
interior cross sections of the left and right branches,
as illustrated in figure 35. The connection of the two
branches passes through this line. From this line,
there is drawn, on each side, two straight lines
inclined by 22.5° in order thus to obtain the
measurements aL and bL that are transferred onto the
branches, as illustrated in figure 39.
Once the measurements aL and bL have been transferred
across on two straight lines inclined by 22.5° on each
branch, the interior points are joined using two
straight lines inclined at 45° as far as the ends of
the branches. The difference between the values of
these segments needs to be transferred onto the main
duct (1), illustrated in figures 37 and 38, and
constitutes the separation between the two primary
portions (1') inclined at 22.5° and the main duct (1).
It will be easy to check that, if the sum of the
interior cross sections of the branches is equal to the
interior cross section of the main duct, this
difference takes the value 0, and the edges of the
pieces need merely to be cut at 45° in the region of
connection of the branches. It is advisable for this
cut to be made first, before the cuts corresponding to
aL and bL.
As before, it is of course necessary to surround the
exterior part of the connections with self-adhesive
tape and to bond the interior part of the connections
of the duct.
WE CLAIM:
1. An insulating panel (2) for a conditioned-air distribution duct (1), said
insulating panel (2) comprising at least one insulating core (3) based on
mineral wool, preferably on rock wool, and possibly comprising an exterior
layer (4) for example based on a thin skin of aluminum, characterized in that
on one exterior face it has a plurality of marks (5) that are straight and
oblique with respect to a longitudinal direction of said panel, said marks
forming two sets of opposing inclinations oriented at an angle J with respect
to said longitudinal direction.
2. The insulating panel (2) as claimed in the preceding claims, wherein
said angle 7 is substantially between 82.5° and 52.5° and preferably
substantially equal to 67.5°.
3. The insulating panel (2) as claimed in either of the preceding claims,
wherein said exterior face also has a plurality of transverse straight marks (6)
oriented at right angles to said longitudinal direction.
4. The insulating panel (2) as claimed in any one of the preceding
claims, wherein said exterior face also has a plurality of longitudinal straight
marks (7) oriented parallel to said longitudinal direction.
5. The insulation panel (2) as claimed in any one of the preceding claims,
wherein said oblique straight marks (5), and possibly said transverse straight
marks (6) and/or said longitudinal straight marks (7) are embodied at least
near the longitudinal edges and preferably across the entire surface of the
exterior face.
6. The insulating panel (2) as claimed in any one of the preceding claims,
wherein said oblique straight marks (5), and possibly said transverse straight
marks (6) and/or said longitudinal straight marks (7) are embodied on the
surface of the exterior face of the exterior layer (4).
7. The insulating panel (2) as claimed in any one of the preceding claims
wherein said transverse straight marks (6) and/or said longituidinal straight
marks(7) intersect said oblique straight marks (5) at points where longitudinal
straight marks (7) of opposing inclination intersect.
8. A distribution duct (1) having a substantially parallelepipedal cross
section, the duct being made from at least one insulating panel (2) as
claimed in any one of the preceding claims.
9. The distribition duct (1) as claimed in the preceding claim, wherein said
duct (1) has a main longitudinal axis P and at least one change of direction C
at an angle ß, altering the main longitudinal axis P into a downstream axis P',
?', said angle ß being substantially between 30° and 60° and preferably
substantially equal to 45°.
10. A method for manufacturing a distribution duct (1) with a substantially
parallelepipedal cross section using at least one insulating panel (2) as
claimed in any one of claims 1 to 7.
11. The manufacturing method as claimed in the preceding claim, wherein
said duct (1) having a main longitudinal axis P and at least one change of
direction C at an angle ß, altering the main longitudinal axis P into a
downstream axis P', P", said angle ß being substantially between 30° and 60°
and preferably substantially equal to 45°.
12.The manufacturing method as claimed in claim 11, wherein said change in
direction C is achieved by cutting each of the faces of said duct from a flat
panel (2).
13. The manufacturing method as claimed in the preceeding claim, wherein
the faces of the duct that are parallel to the plane containing said change in
direction C each have more than four sides in this plane and preferably have
six sides or eight sides.
14. The manufacturing method as claimed in claim 11, wherein said change
in direction C is achieved by completely sectioning a duct (1) into a primary
portion (1') and possibly a secondary portion(1"), and possibly rotating said
primary portion (1') or said secondary portion (1") about its main axis.
15. The manufacturing method as claimed in the preceding claim, wherein
said sectioning is performed on two faces parallel to the plane containing said
change In direction C at the angle 0, measured with respect to a transverse
direction of these faces, and on the other two faces in a transverse direction
of these faces.
16. The manufacturing method as claimed in any one of claims 10 to 15,
wherein said cutting or said sectioning is performed using a cutting
instrument (10) having two blades (15, 16) situated in the same plane, the
cutting edges (17,18) of the respective blades (15,16) being directed at
opposing inclinations and the First cutting edge (17) being shorter in height
than the second cutting edge (18) in the overall cutting or sectioning
direction.
17. The manufacturing method as claimed in claim 16, wherein said cutting
instrument (10) has blades (15,16) directed at an angle 5 with respect to a
guide surface (2).
18. The manufacturing method as claimed in claim 17, wherein ? =d.
19. The manufacturing method as claimed in claim 16, wherein said
cutting instrument has a first cutting edge (17) and a height shorter than the
total thickness of the panel (2) and the second cutting edge (18) has a height
greater than the total thickness of the panel (2).

An insulating panel (2) for a conditioned-air distribution duct (1), said
insulating panel (2) comprising at least one insulating core (3) based on mineral
wool, preferably on rock wool, and possibly comprising an exterior layer (4) for
example based on a thin skin of aluminium, characterized in that on one exterior
face it has a plurality of marks (5) that are straight and oblique with respect to a
longitudinal direction of said panel, said marks forming two sets of opposing
inclinations oriented at an angle γ with respect to said longitudinal direction.

Documents:

1912-kolnp-2004-abstract.pdf

1912-kolnp-2004-claims.pdf

1912-kolnp-2004-correspondence.pdf

1912-kolnp-2004-description (complete).pdf

1912-kolnp-2004-drawings.pdf

1912-kolnp-2004-examination report.pdf

1912-kolnp-2004-form 1.pdf

1912-kolnp-2004-form 18.pdf

1912-kolnp-2004-form 2.pdf

1912-kolnp-2004-form 26.pdf

1912-kolnp-2004-form 3.pdf

1912-kolnp-2004-form 5.pdf

1912-KOLNP-2004-FORM-27-1.pdf

1912-KOLNP-2004-FORM-27.pdf

1912-kolnp-2004-reply to examination report.pdf

1912-kolnp-2004-specification.pdf

1912-kolnp-2004-translated copy of priority document.pdf

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Patent Number

236200

Indian Patent Application Number

1912/KOLNP/2004

PG Journal Number

41/2009

Publication Date

09-Oct-2009

Grant Date

07-Oct-2009

Date of Filing

14-Dec-2004

Name of Patentee

SAINT GOBAIN ISOVER

Applicant Address

18 AVENUE D'ALSACE, F-92400 COURBEVOIE

Inventors:

#	Inventor's Name	Inventor's Address
1	NAVARRO NIEDERCORN GABRIEL	C/CARLOS IV, N°21, 1°A, E-28037 MADRID, ESPAGNE

PCT International Classification Number

F16L 59/02

PCT International Application Number

PCT/FR2003/001854

PCT International Filing date

2003-06-18

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	U 0201601	2002-06-24	Spain
2	U 0201600	2002-06-24	Spain