Radiator made of stamped steel plate, particularly for domestic heating systems

Abstract: The radiator comprises a plurality of radiator elements (10), each of which is formed by a pair of oppositely arranged heads (11-11') that are connected by a plurality of pipes (12). Each head, formed by oppositely arranged and electrically welded half-shells, is provided with cylindrical fittings (13-13') for the electrically welded coupling of the pipes (12). In order to facilitate electric welding of the pipes (12) to the fittings (13), the pipes (12) have a different diameter with respect to the fittings (13).

Description: The present invention relates to a radiator made of a stamped steel plate, particularly for domestic heating systems. EP-A-0477522 discloses a radiator having the features as specified in the preamble of claim 1. In other known radiators of this type, the heads of each element have cylindrical fittings for the connecting pipes; these fittings have the same inside and outside diameter as the pipes, which are butt-joined to said fittings and connected by means of welding beads formed with various electric welding methods. Owing to the limited thickness of the plate used for the heads and the pipes, typically between 8 and 15 tenths of a millimeter, the positioning of the end of the pipes with respect to the fittings of both heads is highly critical, since said pipes must be perfectly axially aligned with the respective fittings essentially to ensure correct execution and tightness of the electric weld but also for aesthetic reasons, since an axial offset between the pipes and the respective head fittings, although slight, can be easily noticed and is perceived as a discontinuity that shows poor workmanship. This considerably complicates the processes for mass-production of said radiators, forcing accurate checks of the gauging of the fittings and of the pipes and of their mutual positioning, entailing considerable production downtimes, use of specialized labor, and high production rejection. A principal aim of the present invention is to eliminate these and other drawbacks and to provide a radiator made of stamped steel plate that can be manufactured with simplified processes that do not require, in particular, accurate checking of the mutual positioning of the pipes and of the head fittings and are therefore economically advantageous and adapted for mass-production. Within the scope of this general aim, the invention also has the further object of providing a radiator that has a pleasant aesthetic appearance and does not require any resumption of the production process after electric welding. According to the present invention this object is achieved by providing a radiator made of stamped steel plate having the specific features stated in claim 1. Essentially, the invention is based on the concept that the pipes used to connect the heads of each radiator element have a different diameter with respect to the fittings provided on said heads; in particular, the outer diameter of the fitting is greater than the inner diameter of the pipe or alternatively the outer diameter of the pipe is greater than the inner diameter of the fitting such that the pipe cannot be fitted over or respectively into the fitting; the invention is also based on the concept of providing the ends of the pipes, or respectively of the fittings, with tapering circular arc-like coupling regions that provide butt-joining between said pipes and said fittings. The invention will become apparent from the following detailed description and with reference to the accompanying exemplifying drawings, wherein: figure 1 is a front view of a radiator formed by a set of radiator elements produced according to the present invention; figure 2 is a sectional view, taken along the plane II-II of figure 1; figure 3 is a sectional view, taken along the plane III-III of figure 2; figure 4 is an enlarged-scale detail view of the joint section referenced by the circle IV in figure 3; figures 5 and 6 are respectively a sectional view and an enlarged sectional view, similar to figures 2 and 4 respectively, of a different embodiment that provides the same advantages. In figure 1, the symbol RT designates a radiator, typically for domestic heating systems, provided by arranging side by side and mutually connecting a plurality of radiator elements, generally designated by the reference numeral 10. Each radiator element 10 is made of stamped steel plate and comprises two heads 11-11' which are connected by a plurality of pipes, typically a set of three pipes 12, which are arranged side by side and parallel to each other. Each head 11 is formed by respective symmetrical half-shells such as 11a-11b which are juxtaposed and electrically welded along respective centerlines S. Cylindrical fittings 13-13' are provided on the heads to connect the ends of the pipes 12, which are in turn electrically welded to said cylindrical fittings. According to the invention and for the specified purposes, the inside and outside diameters of the pipes 12 are different from the corresponding inside and outside diameters of the cylindrical fittings 13. In particular, in the embodiment of figures 1 to 4, the inside and outside radii r 1 -r 2 of the pipes 12 are greater than the corresponding radii r' 1 -r' 2 of the fittings 13 and differ by an amount that is equivalent to 50 to 90% of the thickness "d" of the plate of the pipes and of the fittings, so that the pipe 12, by having an inside diameter that is smaller (by 50 to 10%) than the outside diameter of the fitting 13, cannot be fitted over said fitting. In order to facilitate the electrically-welded butt-joining of the pipes 12 to the fittings 13, the ends of said pipes are provided with tapering circular arc-like connecting regions 12a (figure 4) that act as an abutment for the end of the respective fitting 13. The embodiment of figures 5 and 6, which obviously achieves equal advantages, differs from the embodiment of figures 1 to 4 in that in this case the outside and inside diameters of the pipes 112 of the radiator elements 100 are chosen so that they are smaller than the corresponding outside and inside diameters of the fittings 113 of the heads 110-110' of said elements. In this case, too, the respective outside and inside radii r 1 -r 2 of the pipes and the radii r' 1 -r' 2 of the fittings differ by an amount that is 50 to 90% of the thickness "d" of the plate, so that the outside diameter of the pipe 112 is in any case greater than the inside diameter of the corresponding fitting 113 to prevent the pipe from entering the fitting. Furthermore, according to this embodiment, the end of each fitting 113 is provided with a tapering circular arc-like connecting region 113a that acts as an abutment for the end of the pipe 112. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims: Radiator (RT;100) made of a stamped steel plate, particularly for domestic heating systems, which comprises a plurality of radiator elements (10;110), each element being formed by a pair of oppositely arranged heads (11-11') that are connected by a plurality of pipes (12;112), characterized in that each head, formed by oppositely arranged electrically welded half-shells, is provided with cylindrical fittings (13-13';113) for the electrically welded coupling of said pipes (12;112); and in that the pipes (12;112) that connect the heads (11-11') have a different diameter with respect to the fittings (13;113) provided on said heads, the outer diameter of the fitting (13) being greater than the inner diameter of the pipe (12) or alternatively the outer diameter of the pipe (112) being greater than the inner diameter of the fitting (113) such that the pipe cannot be fitted over or respectively into the fitting. Radiator according to claim 1, characterized in that the pipes (12) that connect the heads (11-11') have larger inside and outside diameters than the corresponding inside and outside diameters of the fittings (13) provided on said heads. Radiator according to claims 1 and/or 2, characterized in that the ends of the pipes (12) that connect the heads (11-11') have tapering circular arc-like connecting regions (12a) that act as an abutment for the end of the respective fitting (13). Radiator according to claim 1, characterized in that the pipes (112) that connect the heads (111-111') have inside and outside diameters that are smaller than the corresponding inside and outside diameters of the fittings (113) provided on said heads. Radiator according to claims 1 and/or 4, characterized in that the end of each fitting (113) of the heads (111-111') is provided with a tapering circular arc-like connecting region (113a) which acts as an abutment for the end of the respective pipe (112). Radiator according to any one or more of claims 2-5, characterized in that the outside and inside radii (r 1 -r 2 ) of the pipes (12-112) are greater, or respectively smaller, than the corresponding outside and inside radii (r' 1 -r' 2 ) of the fittings (13-113) of the heads (11-111) by an amount that is between 50 and 90% of the thickness (d) of the plate that forms said pipes and said heads.

Inventors: GUBBINI AMULIO, PARPAIOLA PIER ANTONIO, GUBBINI, AMULIO, PARPAIOLA, PIER ANTONIO
Applicants: T D A TECNOLOGIE D AUTOMAZIONE, T.D.A. TECNOLOGIE D'AUTOMAZIONE S.R.L.
Application year: 1995
Main classification: F28F9
IPC codes: F28D1, F28F9