Patent EA-005062-B1 (EA)
Title: Method for producing a head element for heaters and head element made by said method
IPC: B21D53/04
Filed: 2002-06-12
Abstract: 1. Method for producing head elements for heaters, characterized in that it includes: preparing of a piece of a sheet metal (1); deep drawing said sheet metal piece (1) to obtain a hollow molded piece (2), defined by a base wall (3), sides (4,5,14,15) joined to and surrounding the base wall and forming an open side (6); cutting the sides (4,5,14,15) along the open side (6), to define a hollow body (8) with an edge (9), which is uniform and extends around said open side (6); making a lateral through aperture (12) on two opposite sides (4,5) to obtain apertured opposite sides; providing connection means (25) around each lateral through aperture (12); making of at least one notch (16), on the apertured opposite sides (4,5), along said edge (9); introducing at least two cores (18) into said edge (9) matching areas (19) without said at least one notch (16); stamping a flange (17) extending around each of said at least one notch and included between said cores (18), so as to close the sheet metal around said cores (18) and in the area of said edge (9), thus widening said notches (16); removing said cores (18) from the hollow body; welding of said edge (9) along said flange (17) of said widened at least one notch (16), so as to obtain a series of holes (21) separated from each other. 2. Method, according to claim 1, characterized in that the fastening means (25) are obtained, on each lateral through aperture (12) by welding a threaded ring (26) around the lateral through aperture (12). 3. Method, according to claim 1, characterized in that the fastening means (25) are obtained on each lateral through aperture (12) by pressing outwards a circular crown (27), extending around each lateral through aperture (12), so as to form a protruding edge (31) on each of said apertured sides (4,5). 4. Method, according to claim 3, characterized in that a threaded ring (38) is placed inside the seat defined by said protruding edge (31). 5. Method, according to claim 3, characterized in that said outward pressing is obtained by inserting a flat core (28) into said hollow body (8), through the open side (6), before the holes (13) are made, with said flat core (28) being equipped with a floating element (29), which is situated to match each lateral through aperture (12) and is pushed outwards alternately in opposite directions, thus causing the forming of the protruding edge (31) on said circular crown (27), while on the outer part of the hollow body (8) a die (30) is situated, to strike against the hollow body (8) and form the protruding edge 31 from outside. 6. Method, according to claim 1, characterized in that two notches (16), spaced from each other, are made on each of said apertured opposite sides (4,5), along said edge (9), to create three free areas (19), and three cores are introduced into said edge (9) positioned to match said free areas (19). 7. Method, according to claim 1, characterized in that the drawing of said metal sheet (1) in order to obtain said hollow molded piece (2) includes a series of subsequent steps. 8. Method, according to claim 1, characterized in that the coupling of the tubular elements (23) with said head element is obtained according to the following steps: a small cylinder (24) is inserted into each hole (13), said small cylinder (24) having a groove made along its circumference, into which a ring (34) of fusible material is inserted; the head of each tubular element (23) to be connected is fitted on the part of the small cylinder (24) protruding from the relative hole (13); the connection area between each tubular element (23) and the head element near the holes (13) and the ring (34) of fusible material is heated thus welding the head element and tubular elements (23) by brazing. 9. A method according to claim 1, wherein said apertured sides (4,5) are larger than the other non-apertured sides. 10. A method for producing head elements for heaters, characterized in that it includes: preparation of a piece of a sheet metal (1); deep drawing of said sheet metal (1) to obtain a hollow molded piece (2), defined by a base wall (3), sides (4,5,14,15) joined to and surrounding the base wall (3) and delimiting an open side (6); cutting the sides (4,5,14,15) near said open side (6), to define a hollow body (8) with an edge (9), which is uniform and extends around said open side (6); making a lateral through aperture (12) on each two opposite sides (4,5) to obtain two apertured opposite sides; making at least one notch (16), on each of said apertured opposite sides (4,5), along said edge (9); introducing at least two cores (18) into said edge (9) in areas (19) without said at least one notch (16); pressing a flange (17) extending around said notches and included between said cores (18), so as to close the sheet metal around said cores (18) and in the area of said edge (9), thus widening said notches (16); removing said cores (18) from the hollow body; welding said edge (9) along said flange (17) of said widened at least one notch (16), so as to obtain holes (21) separated from each other; providing fastening means (25) on each lateral through aperture (12) on each of said apertured opposite sides (4,5). 11. A method, according to claim 10, characterized in that the fastening means (25) on each lateral through aperture (12) are obtained by welding a threaded ring (26) around the lateral through aperture (12). 12. A method according to claim 10, wherein said apertured sides (4,5) are larger than the other nonapertured sides. 13. Head element for heaters, made in a single hollow body (8), defined by a base wall (3), sides (4,5,14,15) joined to and surrounding the base wall (3), at least two holes (13) turned toward the inside of said hollow body (8), with at least one lateral through aperture (12) made on two opposite sides (4,5) defining two apertured sides, characterized in that: said body (8) is obtained from a single part of a deep-drawn metal sheet; said holes (13) are delimited by a press-shaped edge (9) of an open side (6), opposite to said base wall (3) of said hollow body (8), with notches (16) made on said edge (9) and widened by pressing, so as to define pressed flanges (17), which surround the notches (16) and are welded to each other to separate said holes (13); and fastening means (25) are provided on each lateral through aperture (12). 14. Head element, according to claim 13, characterized in that the fastening means (25) on each lateral through aperture (12) are constituted by a threaded ring (26) fastened to a relative apertured side (4,5). 15. Head element, according to claim 13, characterized in that the fastening means (25) on each lateral through aperture (12) include a circular crown (27), surrounding the lateral through aperture (12) drawn outwards to form a protruding edge (31). 16. Head element, according to claim 15, characterized in that a threaded ring (38) is placed inside the seat defined by said protruding edge (31). 17. Head element, according to claim 13, characterized in that notches (16), spaced apart and surrounded by the molded flanges (17), are made on each of said apertured opposite sides (4,5), along said edge (9), to delimit three holes (13). 18. Head element, according to claim 13, characterized in that said apertured sides (4,5) are larger than the other non-apertured sides.