Section of a smoke exhaust pipe of the two-concentric tube type and its manufacturing method

Description

Technical field of the invention

[0001] The present invention relates to the general field of chimney sweeping.

[0002] It relates more particularly to a section of conduit for the creation of a conduit intended, on the one hand, for the evacuation of combustion products generated by a heating appliance, and, on the other hand, for the supply of combustion air to this heating appliance. State of the art

[0003] The optimal operation of certain heating appliances, particularly sealed appliances such as stoves or boilers, requires an air supply, known as “combustion air”.

[0004] To achieve this supply of combustion air, an interesting solution consists of using a combustion product evacuation duct made up of a juxtaposition of sections of ducts, fitted one after the other, and each composed of two concentric tubes: (i) an inner tube, forming a central chamber ensuring the actual evacuation of combustion products from the heating appliance, and (ii) an outer tube, defining with the inner tube opposite, an annular peripheral chamber for the flow of combustion air coming from outside, towards this heating appliance.

[0005] Conventionally, sections of concentric smoke ducts, insulated or not, are assembled mechanically, either by welding, which does not allow their subsequent disassembly, or by screwing, their disassembly then requiring a tool, and the result being unattractive.

[0006] Current solutions are therefore not optimal in the face of growing aesthetic requirements, and also due to technical constraints linked in particular to the processes for painting the outer metal tube, incompatible with plastic materials (such as polypropylene for example) which sometimes make up the inner tube. Sections of smoke ducts of the prior art are known from documents US 4,781,402 A, DE 10 2017 207053 A1, and US 3,872,780 A.

[0007] There is therefore a need to propose other assembly solutions between the inner tube and the outer tube constituting such sections of smoke ducts. Presentation of the invention

[0008] In order to remedy at least some of the aforementioned drawbacks of the state of the art, the present invention proposes a section of smoke duct intended for producing a smoke evacuation duct comprising - a central chamber intended for evacuating the combustion products generated by a heating appliance, and - an annular peripheral chamber intended for supplying combustion air to this heating appliance, which section of flue is of the type with two concentric tubes separated by an annular space and comprises - an outer tube delimited by an outer surface and an inner surface, and - an inner tube delimited by an outer surface and an inner surface, which section of flue comprises centering means for centering said inner tube in said outer tube and making said inner and outer tubes concentric with respect to a central axis, and which section of flue comprises assembly means for assembling said inner tube with said outer tube, this section of flue being characterized in that said assembly means comprise stop structures integral with the outer tube, and blocking structures integral with the inner tube, which stop structures and which blocking structures are capable of being placed in abutment against each other,by a rotational movement of said concentric tubes relative to each other, around said central axis, so as to obtain axial locking of said tubes relative to each other in both axial directions.

[0009] The assembly means between the two tubes are thus hidden, which provides an excellent aesthetic result.

[0010] According to another preferred characteristic, the stop structures and the locking structures are capable of being offset relative to each other so as to allow axial movement of the two tubes relative to each other in both axial directions, to allow unlocking of the two tubes after their assembly.

[0011] The invention thus provides a simple solution which allows the inner tube of the concentric conduit to be easily assembled and disassembled without tools.

[0012] Other non-limiting and advantageous characteristics of the section of smoke duct according to the invention, taken individually or in all technically possible combinations, are the following: The smoke duct section comprises: (a) at least one first stop structure secured to the outer tube adapted to cooperate with at least one first blocking structure secured to the inner tube, forming at least one pair of first stop structure and first blocking structure, which at least one pair of first stop structure and first blocking structure is arranged so that, when said first stop structure and said first blocking structure cooperate by bearing, an axial blocking of the two tubes is obtained relative to each other, in a first axial direction, and (b) at least one second stop structure secured to the outer tube adapted to cooperate with at least one second blocking structure secured to the inner tube, forming at least one pair of second stop structure and second blocking structure,which at least one pair of second stop structure and second blocking structure is arranged so that, when said second stop structure and said second blocking structure cooperate by bearing, they obtain axial blocking of the two tubes relative to each other in the second axial direction. The centering means comprise, at least for one of them, at least two cylinder portions arranged in the same plane and centered on said central axis, which cylinder portions are separated by openings, and which cylinder portions are delimited by two edges in an arc of a circle, one oriented inwards, called the inner edge, and the other oriented outwards, called the outer edge, at least one of which constitutes one of said stop structures. In this case, preferably, the centering means are integral with the outer tube and comprise a concave part of said cylinder portions, intended to cooperate with the outer surface of the inner tube, which cylinder portions are extended by lateral fixing tabs, for their fixing on the inner surface of the outer tube. The locking structures each consist of a locking surface of a locking tab secured to the outer surface of the inner tube. The locking tabs can then be carried by a clamping collar which encircles the inner tube; and the locking surface of the locking tabs preferably extends in a plane perpendicular to said central axis. The dimensions of the locking tabs are adapted to allow their passage through the openings which separate the cylinder portions from the centering means. Preferably, the section of flue comprises locking tabs, some of which cooperate with the outer edge of said centering means and others of which cooperate with the inner edge of said centering means.

[0013] According to yet another feature, at least one of said locking tabs has elasticity in the axial direction, which locking tab comprises a locking lug adapted to cooperate with an edge of said lateral fixing tabs, so as to come to be positioned between the two lateral tabs of a cylinder portion of the centering means, by the elasticity of said locking tab, during said rotational movement of said concentric tubes relative to each other.

[0014] The present invention also relates to a method for manufacturing a section of smoke duct for producing a smoke evacuation duct, which section of smoke duct comprises - an outer tube delimited by an outer surface and an inner surface, and - an inner tube delimited by an outer surface and an inner surface, which section of flue comprises centering means for centering said inner tube in said outer tube and making said inner and outer tubes concentric with respect to a central axis, the method consisting of: providing an outer tube whose inner surface comprises stop structures, providing an inner tube whose outer surface comprises locking structures, and pressing said stop structures against said locking structures, by a rotational movement of said concentric tubes relative to each other, around said central axis, so as to obtain axial locking of said tubes relative to each other in both axial directions.

[0015] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. Detailed description of the invention

[0016] In addition, various other characteristics of the invention emerge from the appended description given with reference to the drawings which illustrate non-limiting embodiments of the invention and where: [ Fig. 1 ] is a schematic view of the end of a section of flue pipe according to the invention; [ Fig. 2 ] is a schematic view in longitudinal section of the smoke duct section, according to section plane 2-2 of the figure 1 ; [ Fig. 3 ] is an enlarged view of detail A of the figure 2 ; [ Fig. 4 ] is a schematic perspective view of the section of flue still according to section plane 2-2 of the figure 1 ; [ Fig. 5 ] is an enlarged view of detail B of the figure 4 ; [ Fig. 6 ] is a schematic perspective view of a clamping collar provided with locking tabs, constituting the means for locking the section of smoke duct of the figures 1 to 5 ; [ Fig. 7 ] is a schematic perspective view illustrating a step in the assembly of the inner tube in the outer tube, for the manufacture of the section of flue of the figures 1 to 5 ; [ Fig. 8 ] is a schematic perspective view illustrating a subsequent step in the assembly of the inner tube in the outer tube, for the manufacture of the flue section of the figures 1 to 5 ; [ Fig. 9 ] is a schematic perspective view illustrating a stage in the disassembly of the two inner and outer tubes, after their assembly. The figures 1 to 5illustrate a possible embodiment of a section of flue duct 1 according to the invention, which can be assembled by fitting together with other sections of identical or similar ducts, to form a flue duct for housing.

[0017] The concentric flue thus formed may, for example, be intended to extend within a technical duct between a sealed heating appliance such as a stove or boiler, and an external outlet, for example constituted by a roof terminal.

[0018] The section of flue duct 1 is of the type comprising (i) a central chamber C, for the evacuation via the external outlet of the combustion products generated by the heating appliance, and (ii) a peripheral chamber P, surrounding the central chamber C, for the supply of combustion air to the heating appliance from said external outlet.

[0019] For this, the section of smoke duct 1 comprises two tubes concentric with respect to a central axis 1a, namely: - an outer tube 2 delimited by an outer surface 21 and an inner surface 22, and - an inner tube 3 delimited by an outer surface 31 and an inner surface 32.

[0020] The inner surface 32 of the inner tube 3 delimits the central chamber C intended for the passage of the combustion products generated by the heating appliance. The inner surface 22 of the outer tube 2 and the outer surface 31 of the inner tube 3 together delimit the peripheral annular chamber P intended for the passage of the combustion air of the heating appliance.

[0021] The outer tube 2 may be made of metal, for example stainless steel; and the inner tube 3 may be made of metal or plastic material, for example polypropylene.

[0022] The flue section 1 comprises centering means 4 for centering the inner tube 3 in the outer tube 2 in order to make them concentric with respect to the central axis 1a, as well as assembly means 5 for assembling the inner tube 3 with the outer tube 2, detailed below.

[0023] The flue section 1 further comprises two ends 11 and 12, one of the male type and the other of the female type, to allow assembly by fitting with an identical or similar flue section, or with the heating appliance or the external outlet equipment. One of these two ends (in this case the end marked 12) comprises a clamp 13 intended to secure the fitting.

[0024] As detailed below, the assembly means 5 for assembling the inner tube 3 with the outer tube 2 comprise stop structures 51 secured to the outer tube 2, and locking structures 52 secured to the inner tube 3. And these stop structures 51 and locking structures 52 are arranged to be able to be pressed against each other, by a rotational movement of the two concentric tubes 2 and 3 relative to each other, around the central axis 1a, so as to obtain axial locking of said tubes 2, 3 relative to each other, in both axial directions. In addition, the corresponding rotational movement is reversible so as to allow an offset of the stop structures 51 and the locking structures 52, after assembly, to disassemble / disassemble the two tubes 2 and 3.

[0025] The centering means 4 and the assembly means 5 are here arranged near one of the ends 11 of the section of smoke duct 1, in the peripheral annular chamber P.

[0026] The centering means 4 are adapted to center the inner tube 3 in the outer tube 2 in order to make them concentric; and they also comprise the stop structures 51 of the assembly means 5.

[0027] The centering means 4 are here integral with the outer tube 2. They comprise two cylinder portions 41 arranged in the same plane and centered on the central axis 1a, extended on the sides by lateral fixing lugs 42.

[0028] The cylinder portions 41 are delimited by two arcuate edges 51 which constitute the aforementioned stop structures 51 of the assembly means 5.

[0029] One of these arcuate edges 51a (called outer edge 51a) is oriented outwards, that is to say towards the end 11 of the section of smoke duct 1 nearby; and the other of these arcuate edges 51b (called inner edge 51b) is oriented inwards, that is to say towards the central part of the section of smoke duct 1.

[0030] The two arcuate edges 51a, 51b which constitute the stop structures 51 extend in a plane which is perpendicular to the central axis 1a.

[0031] The concave parts 41' of the two cylinder portions 41 are centered on the central axis 1a and they extend over a virtual cylinder whose diameter corresponds, within clearance, to the diameter of the external surface 31 of the internal tube 3.

[0032] The two cylinder portions 41 are arranged diametrically opposite relative to the central axis 1a; they are separated by openings 6, also diametrically opposite.

[0033] The free end 43 of the fixing lugs 42 is secured to the inner surface 22 of the outer tube 2 by welding.

[0034] The fixing lugs 42 are delimited by free edges 42a and 42b which extend the circular arc edges 51a, 51b of the cylinder portions 41, and which also extend in a plane perpendicular to the central axis 1a.

[0035] The locking structures 52 of the assembly means 5 each consist of a locking surface 52 of a locking tab 53 secured to the outer surface 31 of the inner tube 3 by means of a clamping collar 54.

[0036] The clamp 54 with its two locking tabs 53 is shown in isolation on the figure 6. It comprises a screw-nut type clamping means 55 for clamping it around the inner tube 3. The two locking tabs 53 extend towards the outside of the clamping collar 54, in a diametrically opposite manner; they can be made in one piece with the clamping collar 54 or be added and secured for example by welding.

[0037] Once the clamping collar 54 is mounted on the periphery of the inner tube 3 and fixed by the clamping means 55, each locking tab 53 extends in a plane perpendicular to the central axis 1a. And the two locking tabs 53 extend in different planes, separated by a distance which corresponds to the distance between the arcuate edges 51a, 51b of the cylinder portions 41. The two locking tabs 53 extend cantilevered from the clamping collar 54 which carries them; and these locking tabs 53 have elasticity in the axial direction.

[0038] In this way, it is understood that the locking surface 52 of one of the locking tabs 53 is adapted to cooperate with one of the circular arc-shaped edges 51a, 51b of one of the cylinder portions 41, and that the locking surface 52 of the other locking tab 53 is adapted to cooperate with the other of the circular arc-shaped edges 51a, 51b of the other cylinder portion 41.

[0039] The dimensions of the locking tabs 53 are adapted to allow their passage through the openings 6 which separate the cylinder portions 41 from the centering means 4.

[0040] On the figures 3 , 5 And 6 in particular, we note the presence of a locking lug 56 which extends from the end of the locking tabs 53, each in the direction of the plane in which the other locking tab 53 extends. The locking lugs 56 can extend at 90° relative to the plane of the locking tabs 53, or at a slightly less significant angle.

[0041] The sides of the locking lugs 56 are provided at an angle, converging towards each other from the end of the locking tab 53 to facilitate the locking operation, as explained later in the description.

[0042] Once the outer tube 2 is fitted with the centering means 4, and the inner tube 3 is fitted with the clamping collar 54 equipped with the locking tabs 53, the inner tube 3 is inserted into the outer tube 2, for example by the end marked 11, in the manner illustrated in the figure 7 .

[0043] During this insertion, the inner tube 3 is guided concentrically to the outer tube 2 by the two concave parts 41' of the cylinder portions 41 of the centering means 4.

[0044] Before the clamping collar 54 with its locking tabs 53 reaches the centering means 4, the locking tabs 53 are positioned in the axis of the openings 6; and when the clamping collar 54 with its locking tabs 53 reaches the centering means 4, one of the locking tabs 53 passes through one of the openings 6 and comes to be located in the plane of the inner edge 51b of the cylinder portions 41; the second locking tab 53 comes to be located in the plane of the outer edge 51a of the cylinder portions 41.

[0045] The operator can then rotate the inner tube 3 relative to the outer tube 2 around the central axis 1a, as illustrated in the figure 8 .

[0046] The locking lugs 56 of the locking tabs 53 then come into abutment against the opposite free edge 42a, 42b of the lateral fixing tabs 42 of the cylinder portions 41. A rotational force allows the locking lugs 56 to pass the level of this free edge 42a, 42b of the lateral fixing tabs 42, thanks to the axial elasticity of the locking tabs 53, this passage being further facilitated by the slanted shape of the sides of the locking lugs 56.

[0047] An extension of the rotational movement allows the locking tabs 53 to come into position opposite the cylinder portions 41, so that the locking structures 52 cooperate with the stop structures 51a, 51b.

[0048] It is understood that one of the stop structures 51a cooperates by pressing with a first locking structure 52, to obtain axial locking of the tubes 2 and 3 relative to each other, in a first axial direction, and that the other stop structure 51b cooperates with the second locking structure 52 to obtain axial locking of said tubes 2, 3 relative to each other in the second axial direction.

[0049] The two tubes 2 and 3 are thus assembled and locked. The locking lugs 56 located between the lateral fixing lugs 42 of the cylinder portions 41 prevent involuntary disassembly of the two tubes 2, 3.

[0050] To ensure optimum concentricity of the two tubes 2 and 3, after assembly, an additional, removable centering means 7 can be positioned at the other end 12 of the section of flue duct 1.

[0051] As can be seen on the figure 1, this additional centering means 7 can be constituted by a metal wire shaped into a triangle so that it allows three “branches” to be produced which tighten onto the inner tube 3, and the angles of which can substantially make contact with the inner wall 22 of the outer tube 2, while leaving a clearance allowing the assembly by fitting the sections of conduit together.

[0052] The disassembly of the two tubes 2 and 3 is carried out by a reverse rotation movement, as illustrated in the figure 9 , after removal of the additional centering means 7. The locking lugs 56 are deactivated by applying an additional rotational force at the level of their passage on the free edges 42a, 42b, opposite, of the lateral fixing lugs 42.

[0053] As implementation variants: the flue section 1 may comprise a centering / assembly device 4, 5 as described above, at each of its ends. the flue section 1 may comprise a centering means and a clamping collar equipped with a single locking tab 53 (or several locking tabs located in the same plane), at each of its ends. In this case, the locking tabs 53 cooperate either with the inner edges 51b of the cylinder portions 41, or with their outer edges 51a. only one of the locking tabs 53 may be equipped with a locking lug 56. the centering means 4 may be integral with the inner tube 3 and the locking tabs 53 integral with the outer tube 2. the centering means 4 may each consist of more than two cylinder portions 41 with lateral fixing tabs 42.

[0054] The present invention provides a solution with a good aesthetic appearance and allows the two tubes of the concentric conduit section to be mounted and dismounted without tools.

[0055] The assembly allows the concentricity of the tubes to be maintained and provides a fixed point to control longitudinal movements, particularly in the event of different expansions of the 2 tubes (metal and plastic).

[0056] The present invention also makes it possible to carry out surface treatments of the outer metal tube, such as liquid paint, powder paint or copper plating for example, these treatments being incompatible with the plastic materials (polypropylene type) which sometimes make up the inner tube.

[0057] It should be noted that, in these figures, the structural and / or functional elements common to the different variants may have the same references.

Claims

1. Section of smoke duct (1) for assembling a smoke exhaust duct comprising - a central chamber (C) intended for exhausting combustion products produced by a heating appliance, and - an annular peripheral chamber (P) intended for providing combustion air to that heating appliance, said section of smoke duct (1) being of the type of two concentric tubes separated by an annular space and comprising - an outer tube (2) delimited by an outer surface (21) and an inner surface (22), and - an inner tube (3) delimited by an outer surface (31) and an inner surface (32), said section of smoke duct (1) comprising centering means (4) for centering said inner tube (3) inside said outer tube (2) and making said inner tube (3) and outer tube (2) concentric with respect to a central axis (1a), and said section of smoke duct (1) comprising assembling means (5) for assembling said inner tube (3) with said outer tube (2), said assembling means (5) comprising stopping structures (51) fixed to the outer tube (2) and blocking structures (52) fixed to the inner tube (3), characterized in that said stopping structures (51) and said blocking structures (52) are able to be pressed against each other by a rotating movement of the concentric tubes (2, 3) relative to each other around said central axis (1a), in order to obtain an axial locking of the tubes (2, 3) relative to each other in the two axial directions.

2. Section of smoke duct (1) according to claim 1, characterized in that said stopping structures (51) and said blocking structures (52) are able to be offset relative to each other so as to allow an axial movement of said tubes (2, 3) relative to each other in the two axial directions.

3. Section of smoke duct (1) according to anyone of claims 1 or 2, characterized in that it comprises: - at least one first stopping structure (51a) fixed to the outer tube (2) and able to cooperate with at least one first blocking structure (52) fixed to the inner tube (3), forming at least one pair (51a, 52) of first stopping structure and first blocking structure, said at least one pair (51a, 52) of first stopping structure and first blocking structure being arranged so that, when said first stopping structure (51a) and said first blocking structure (52) cooperate by being pressed against each other, an axial blocking of said tubes (2, 3) relative to each other in a first axial direction is obtained, and - at least one second stopping structure (51b) fixed to the outer tube (2) and able to cooperate with at least one second blocking structure (52) fixed to the inner tube (3), forming at least one pair (51b, 52) of second stopping structure and second blocking structure, said at least one pair (51b, 52) of second stopping structure and second blocking structure being arranged so that, when said second stopping structure (51b) and said second blocking structure (52) cooperate by being pressed against each other, an axial blocking of said tubes (2, 3) relative to each other in the second axial direction is obtained.

4. Section of smoke duct (1) according to anyone of claims 1 to 3, characterized in that said centering means (4) comprise, at least for one of them, at least two cylinder portions (41) situated in a same plane and centered with respect to the central axis (1a), said cylinder portions (41) being separated by openings (6), and said cylinder portions (41) being delimited by two edges (51a, 51b) arranged in an arc of a circle, one (51a) being oriented to the outside, the so-called outer edge (5a), and the other one being oriented to the inside, the so-called inner edge (51b), at least one of them forming one of said stopping structures (51).

5. Section of smoke duct (1) according to claim 4, characterized in that said centering means (4) are fixed to the outer tube (2) and comprise a concave part (41') of said cylinder portions (41) that is intended to cooperate with the outer surface (31) of the inner tube (3), said cylinder portions (41) being extended by lateral fixing brackets (42) for fixing them on the inner surface (22) of the outer tube (2).

6. Section of smoke duct (1) according to anyone of claims 4 or 5, characterized in that each one of said blocking structures (52) consists of a blocking surface (52) of a blocking bracket (53) fixed to the outer surface (31) of the inner tube (3).

7. Section of smoke duct (1) according to claim 6, characterized in that said blocking brackets (53) are fixed to a clamping ring (54) which surrounds the inner tube (3).

8. Section of smoke duct (1) according to anyone of claims 6 or 7, characterized in that said blocking surface (52) of the blocking brackets (53) extends in a plane perpendicular to the central axis (1a).

9. Section of smoke duct (1) according to anyone of claims 6 to 8, characterized in that the dimensions of said blocking brackets (53) are arranged so as to allow their passing through said openings (6) which separate the cylinder portions (41) of the centering means (4).

10. Section of smoke duct (1) according to anyone of claims 6 to 9, characterized in that it comprises blocking brackets (53), some of them cooperating with the outer edge (51a) of the centering means (4), and others cooperating with the inner edge (51b) of the centering means (4).

11. Section of smoke duct (1) according to anyone of claims 6 to 10 depending on claim 5, characterized in that at least one of the blocking brackets (53) is elastic in the axial direction, said blocking bracket (53) comprising a blocking ergot (56) arranged for cooperating with an edge (42a, 42b) of the lateral fixing brackets (42), in order to position between the lateral brackets (42) of a cylinder portion (41) of the centering means (4) by means of the elasticity of the blocking bracket (53) during the rotating movement of said concentric tubes (2, 3) relative to each other.

12. Method of manufacturing a section of smoke duct (1) for assembling a smoke exhaust duct, said section of smoke duct (1) comprising - an outer tube (2) delimited by an outer surface (21) and an inner surface (22), and - an inner tube (3) delimited by an outer surface (31) and an inner surface (32), said section of smoke duct (1) comprising centering means (4) for centering said inner tube (3) inside said outer tube (2) and making said inner tube (3) and outer tube (2) concentric relative to a central axis (1a), then - provide an outer tube (2), the inner surface (22) thereof comprising stopping structures (51), - provide an inner tube (3), the outer surface (31) thereof comprising blocking structures (52), characterized by the step of pressing said stopping structures (51) against said blocking structures (52) by a rotating movement of the concentric tubes (2, 3) relative to each other around said central axis (1a) so as to obtain an axial locking of said tubes (2, 3) relative to each other in the two axial directions.