DK2131134T3 - A method for placing a sealing plate on an end of a tubular member - Google Patents

Description

Description terial of which, by capillarity, runs along the channels and reaches all the contact zones between the plate and the [0001] The present invention relates to an original tubular element; the following cooling enables solidifica- method for applying a metal plate to an end of a tubular tion of the molten metal, guaranteeing joint stability and element, also made of metal, with the aim of closing a seal. head thereof. [0014] The presence of a ring of fusible material, the [0002] The need to perform the above operation is fre- same for all plates, guarantees absolute constancy and quentand, in accordance with specific needs, the method repeatability of the result, independently of the position used is the one which seems most appropriate to the assumed in the heating kiln. particular case; for exam pie, it may be necessary to guar- [0015] In all the known solutions described above, the antee a liquid or a gas seal coupling, or it may not. junction line between the plate and the tubular element [0003] In the field of thermal sanitary plants for bath- is on the flanks thereof; if the fixing is done by welding, rooms and the like, the use of heating radiators is known, the aesthetic result is not appealing even after lapping, which are constituted by a pair of manifolds, arranged while with the heat-welding paste or the ring of fusible vertically, mutually parallel and interconnected by a plu- material the situation is improved, although the line is still rality of conduits, arranged perpendicular at different visible as it is highlighted by the subsequent enamelling, heights. [0016] The need to realise a step in the plate means [0004] The upper and lower ends of the vertical man- that the plate must have a total thickness which is suffi- ifolds are closed by relative plates having profiles which cient to leave, at the edge thereof, an adequate residual correspond to the section of the manifolds themselves, thickness; in practice, these plates have a thickness of which are preferably semi-oval. in the region of 3.5 mm. DE3936251 which represents [0005] The plates can be solid or can afford, in a central the preamble of claim 1 discloses a refrigerant receiver zone thereof, a threaded collar for connection of the ra- for use in motor vehicle air conditioner, which has a tu- diator to the water line of the heating plant. bular body, in which an annular seating is afforded atone [0006] In the above-cited case, it is obvious that the of its open ends, the seating being defined by an upper joint between the plate and the end of the manifold must and a lower projection made by means of electromag-be one that ensures liquid seal. netic forming.

[0007] A first known method comprises welding the [0017] DE3936251 also discloses a bottom closure plate to the tubular element, with the drawbacks which with an obliquely inclined perimeter which gives the clo- this leads to in terms of time and costs for the use of sure a truncoconical conformation, with the peripheral specialised personnel, needed not only for the welding, edge of the bottom closure being clamped between the but also for the following lapping and seal control oper- lower and the upper projection. ations. [0018] The aim of the present invention is to provide a [0008] A further known method includes realising, in method for applying a closing plate to the end of a tubular the edge of the plate: a small step destined to define a element, which enables obtaining a mechanically stable rest for the tubular element and for centring, with respect joint without the use of any extra material, and which at to the tubular element, the plate itself, thanks to its partial the same time guarantees an aesthetically improved reinsertion in the mouth of the tubular element. suit with respect to what can be obtained with traditional [0009] Between the contact zones of the plate and the methods. end of the tubular element, before mounting a special [0019] A further aim of the invention relates to the pro- heat-welding paste is manually applied, which paste, fol- viding of a valid method even where a sealed coupling lowing a suitable heat treatment, makes the fixing unre- is to be achieved, by predisposing special operating movable as well as guaranteeing a seal against leaks. and/or enactment stages which are similar to those in [0010] The result of the operation, in particular in rela- thepriorart. tion to the seal, depends on a correct spreading of the [0020] Astillfurtheraimoftheprocessconsistsin being paste over the whole contact perimeter. defined by simple and rapid actuation stages, which can [0011] In order to obviate the limits of the above solu- be realised with constant results, using equipment having tion, the applicant filed a PCT/EP application, contained costs and independently of the ability of the PCT/EP2007061948, relating to a "Plate couplable to an personnel doing the operations. opening edge provided in a tubular element, and a meth- [0021] A further aim of the invention is to provide a od for constraining the plate to the edge." method which can be used both with solid plates and with [0012] The above application relates to a plate inter- plates having a threaded central sleeve. nally provided with a first annular channel in which a ring [0022] The characteristics of the method of the inven- of low-fusion point brazing material is blocked; further tion will better emerge from the following description, in annular channels are arrayed spoke-fashion from thefirst accordance with what is set out in the claims and with annular channel and extend towards the edge. theaidoftheaccompanyingfiguresofthetablesofdraw- [0013] After mounting the plate on the tubular element ings, in which: there is a stage of heating which fuses the ring, the ma- figure 1 is an exploded perspective view of a portion wards the inside in order to form the above-men- of a tubular element and two different plates to be tioned perimeter rest step 13 (figure 3). alternatively coupled thereto; [0028] An annular lip 11 is thus defined externally on figure 2 is a front view of the same pieces of figure the annular seating 12, which lip 11 is slimmer than the 1, which highlights constructional aspects of the border of the tubular element 1 (see also figure 3). plates and a stage of the method relating to the tu- [0029] In a preferred embodiment of the method, a bular element; stage of rounding the edge 110 of the annular lip (figure 4) is included in the preparation of the tubular element 1. figures 3 and 4 illustrate, in large-scale, correspond- [0030] The realisation of the plate 2,20 involves shaping axial sections of the tubular element, following ing it (in plan view) such as to obtain a profile which is realisation of successive operating stages of the complementary to the profile of the annular seating 12 method; (figure 1), with a cutting action such that the perimeter surfaces 22 which result have an oblique inclination, thus figure 5 illustrates, in a similar view to preceding fig- determining a truncoconical conformation of the plate 2, ures 3 and 4, the following stage of insertion of the 20 (figure 2), the thickness S of which must be equal to plate into the tubular element; the depth P of the annular seating 12, at least over a certain width of the relative perimeter edge 23. figure 6 illustrates, in a similar view to figure 5, the [0031] The plate 2, 20 is preferably fashioned from a following stage of mechanical blocking of the plate flat metal sheet having a constant thickness S, which is to the element. equal to the thickness S of the depth P of the seating 12.

[0032] In order to obtain the plate 20 in which the [0023] With reference to the figures of the drawings, 1 threaded sleeve 21 is afforded, the stage of realisation denotes a metal tubular element, for example a metal includes drawing, perforating and tapping operations, tubular element 1 which is of the type used in a thermal apart from the operations described above. radiator for installation in a bathroom, and is applicable [0033] Sealing means 30 are associated to the plates to one of the two vertical manifolds, to which reference 2, 20 of the embodiment, which sealing means 30 are was made in the preamble hereto. destined to guarantee liquid seal of the coupling between [0024] The ends of the tubular element 1 are destined the plates 2, 20 and the tubular element 1; the sealing to be sealedly closed by metal plates which can be solid, means 30, not illustrated in detail, are advantageously as in a first embodiment denoted by 2, or, in a second of the type described in the patent application mentioned embodiment denoted by 20, can afford a sleeve 21 in a herein above, and comprise a ring 31 of low-fusion point central zone thereof, which sleeve 21 is internally thread- brazing material, schematically denoted by broken lines ed for connecting the radiator to the water line of the in figure 2. heating plant (figure 1). [0034] Thering31 is fixed by friction force to an annular [0025] The method of the present invention concerns channel 32 (visible in the plate 20 in figure 2) connected stages which involve both the preparation of the end of to other channels developing spoke-fashion towards the the tubular element 1 and the realisation of the plate 2, edge (not illustrated). 20 and stages which relate to mutual assembly thereof. [0035] The stages of the method for application of the [0026] The preparation of the end of the tubular ele- plate 2, 20 to the tubular element 1 comprise: ment consists in realising, in the mouth 10 thereof, an annular seating 12 having a predetermined depth P inserting the plate 2, 20 in the annular seating 12, shaped to define a perimeter rest step 13 in a relative such that the perimeter cut surfaces 22 exhibit rebottom situated internally of the tubular element 1. spective converging inclinations in a vertex located [0027] According to the invention, the annular seating externally on the tubular element 1 (figure 5); 12 is obtained by means of successive operations of cold plastic deformation, in particular: fashioning the annular lip 11 in order to superpose it on the perimeter cut surfaces 22 and obtaining, in calibrating (denoted by C in figure 2) an inside of the this way, a mechanical blocking of the plate 2, 20 to tubular element 1, starting from the mouth 10 and the tubular element 1 (figure 6). going down to a predetermined depth L (see figure 2 again); [0036] On conclusion of this last operation, as already mentioned, the plate 2, 20 is unremovably fixed to the moulding the annular seating 12, having the same tubular element 1 and, should the coupling not require shape as the calibrated internal section of the tubular further seal characteristics, the application might be con- element 1 and having uniformly larger dimensions sidered complete. than the calibrated internal section, such that the [0037] In the specific case, however, that a seal is remoulding action causes material to be pressed to- quired, the method comprises a supplementary stage, using the sealing means 30.

[0038] With reference to the described example, this stage consists in heating the tubular element-plate assembly to a temperature above the fusion temperature of the ring 31, for a predetermined time, followed by a cooling of the assembly in order to obtain a new solidification of the metal of the ring 31, distributed in the contact zones between the plate 2, 20 and the tubular element 1.

[0039] The sealed coupling between the plate 2, 20 and the tubular element 1 can obviously be realised, alternatively to what has been described, by a bead of heatwelding paste, mentioned in the preamble, distribution, in preparation, between the contact zones.

[0040] From the above the positive characteristics of the described method clearly emerge, which characteristics enable the aims indicated in the preamble to be fully attained.

[0041] Firstly, the plate is unremovably fixed merely by mechanical action, entirely contrary to all the known solutions, thanks to the snug fit created by the profiling of the annular lip of the tubular element.

[0042] Further, the conformation of the seating, and consequently the plate, locates the joint line between the two parts in the head of the tubular element, thus in a much less visible zone than on the flank; this leads to obvious benefits from the overall aesthetic point of view.

[0043] Further, the joint line lies on a plane, so that any lapping or sanding operations which might be desired to further reduce the visibility of the line are evidently very simple and effective.

[0044] The described method enables easily obtaining couplings with or without seal, according to needs.

[0045] With the method of the invention, the need to realise the step in the edge of the plate is eliminated and, consequently, the plate can be slimmer; by way of example, metal sheeting of 2 mm thickness can be used instead of the 3.5 mm thickness required for prior-art plates.

[0046] Considering that the above-mentioned plates, in the cited technical sector, are produced in very high numbers, it can be understood how the ensuing savings are of not inconsiderable entity.

[0047] All of the stages of the method are simple and rapid to actuate, with an absolute repeatability in terms of results, by equipment having contained costs, without the need to use specialised personnel.

[0048] The proposed method is advantageous, in general, for all cases in which the application of a metal plate for closing the head of a metal tube is required; in the particular technical sector of the described example, the fact that all the coupling stages of the plate are the same both when the plate is solid and when it is provided with a threaded central sleeve is much appreciated.

[0049] Flowever the above description is intended to be of non-limiting nature, and any modifications to detail in the actuation of the described stages are considered to fall within the ambit of protection thereof, as set out in the following claims.

Claims (5)

A method of placing a closure plate (2, 20) on one end of a tubular member (1), comprising: realizing an annular seat (12) in a mouth (10) of the tubular member (1), which is annular seat (12) has a predetermined depth (P) and is shaped so as to define a resting circumference (13) at a bottom thereof situated internally of the tubular member (1); realizing the plate (2, 20), with a plane profile complementary to a profile of the annular seat (12), wherein circumferential cutting faces (22) of the profile are inclined inclined to obtain a cone-shaped formation of the plate (2, 20) and wherein a thickness (S) of the plate is substantially equal to the depth (P) of the annular seat (12), at least relative to a predetermined width of a circumferential edge (23) thereof; inserting the plate (2, 20) into the annular seat (12) so that the circumferential cutting faces (22) of the profile exhibit respective slopes in parallel with a point located externally of the tubular element (1); forming an annular lip (11) of the tubular element (1) located externally of the seat (12), to overlay the annular lip (11) onto the circumferential cutting surfaces (22), thereby providing a mechanical blockage of the plate (2) , 20) to the tubular member (1); characterized in that the step of realizing the annular seat (12) consists in successive plastic cold deformation operations of the tubular member (1), and in that the plastic cold deformation operations comprise: calibrating an inside of the tubular member (1) beginning from the mouth (10) and reaches a predetermined depth (L); forming the annular seat (12) having the same shape as the calibrated inner portion of the tubular member (1) and having uniformly larger dimensions than the calibrated inner portion of the tubular member (1) so that the forming action causes some material being intercepted and pressed against an inside of the tubular member (1) to form the aforementioned circumferential step (13). A method according to claim 1, characterized in that sealing means (30) are associated with the plate (2, 20) and subsequently activating the step of forming the sealing means (30) to realize a sealed coupling between the plate (2, 20). ) and the tubular member (1). Method according to claim 1, characterized in that, in the step of realizing the annular seat (12), it comprises a rounding of the edge (110) of the annular lip (11). Method according to claim 1, characterized in that actions for providing an internal threaded sleeve (21) in a central zone of the plate (2, 20) are included in the step of realizing the plate (2, 20). Method according to claim 4, characterized in that the actions for defining the threaded sleeve (21) comprise acts of pulling, perforating and threading.