METHOD OF JOINING CONNECTION PLATES

Abstract: The present invention relates to a method of securing connection tags to electrical conductors in thermal foils and the like in which a contact plate is riveted in place near a hole passing through plastic layers (1, 2) and a metal part (3). In this method the contact plate (9) is riveted in place near a hole (4) passing through the plastic layers and a metal foil (3) arranged adjacent to the layers (1, 2), by means of a hollow rivet (6) which is passed through the hole. On the opposite side of the hole the rivet has been bent around an upset (8) at the lower edge of the hole, the hole (4) having been made with the aid of a mandrel (5), suitably hot and at least partly conical in shape, so that the upper edge of the hole is flanged to a recessed sealing surface for the rivet (6), the central part has been formed to an exposed cylindrical metal contact surface (7) against the rivet (6), and the lower side to a sealing upset (8), preferably reinforced at the edge, increasing the contact pressure and hermetically sealing the area around the contact surface.

Description: METHOD OF JOINING CONNECTION PLATES . Technical field The present invention relates to a method of securing electrical connection tags to electrical conductors in printed circuits in thermal foils and the like, in which a contact plate is riveted in place near a hole passing through plastic layers and a metal part. Background Art A problem with thermal foils and other components having printed circuits is that the electrical conductors are extremely thin which makes it difficult to attach contact plates and similar contact members without risk of damage, sparking, poor contact, etc. Summary of the Invention The object of the invention is to provide a method for solving this and other associated problems, and is characterised in that the contact plate is riveted in place near a hole passing through the plastic layers and a metal foil arranged adjacent to the layers, by means of a rivet, preferably a hollow rivet, which is passed through the hole and bent on the opposite side around an upset at the lower edge of the hole, the hole being made with the aid of a mandrel, suitably hot and at least partly conical in shape, so that the upper edge of the hole is flanged to a recessed sealing surface for the rivet, the central part is formed to an exposed cylindrical metal contact surface against the rivet, and the lower side to a sealing upset, preferably reinforced at the edge, increasing the contact pressure and hermetically sealing the area around the contact surface. A reliable and easily applied contact to the contact plate is thus obtained from the metal foil, and such a thermal foil can easily be applied in a floor with flooring on top with negligible risk of damage to the thermal foil or the flooring. In a preferred embodiment a ring with protrusions directed axially downwards is applied between the contact plate and the upper plastic layer, said ring being pressed through the layer into contact with the metal foil during riveting. This provides better electrical contact between contact plate and metal foil. The ring is suitably coated with electrically conducting paint. Drawings The invention will be described in more detail with reference to the accompanying drawings in which Figure 1 shows a hole produced in what is to become a metal foil, Figure 2 shows application of a hot mandrel, Figure 3 removal of the mandrel, Figure 4 application of the contact plate and Figures 5 and 6 the arrangement of an intermediate ring provided with protrusions. Description of the Drawings Figure 1 shows two plastic layers 1, 2 with a metal foil 3 located between them. A hole 4 (diameter Dl) is produced in these three layers 1-3 by means of punching, for instance. The plastic layer 1 may have a thickness of 0.05 mm, for instance, and the layer 2 a thickness of approximately 0.1 mm. The foil 3 is approximately 0.01 mm thick. Figure 2 shows flanging of the hole 4 by means of a conical or partly conical mandrel 5 (temperature 100-300°C). Flanging is performed to a diameter D2 and the ratio D1.D2 is chosen so as to ensure crack-free flanging and suitable fit to the hollow rivet applied subsequently. Figure 3 shows how the mandrel 5 has been removed, the flange hole (D2) thus having been shaped to provide a recessed sealing surface for the hollow rivet 6. The central part has been formed to an exposed metal contact surface 7 against the rivet 6. A sealing upset 8, reinforced at the edge, is formed on the lower side of the hole, increasing the contact pressure and hermetically sealing the area around the contact surface 7. Figure 4 shows how a contact plate 9 has been riveted in place by means of the hollow rivet 6 which has also been bent around the upset 8 on the lower side, thereby producing an electrically conducting connection between metal foil, hollow rivet and contact plate, which is also protected against oxidization. Figure 5 shows the alternative embodiment with a studded ring 10 between the contact plate 9 and the metal foil 3, where the entirely or partially axially directed studs are pressed through the upper layer of plastic 1 into contact with the metal foil 3. The ring 10 is suitably filled with electrically conducting paint, for example mixed with graphite, which fills any cavities and eliminates deformations when applied. Figure 6 shows more in detail the embodiment according to the invention with a studded ring 10 filled with electrically conducting paint, for example mixed with graphite, inserted between the contact plate 9 and plastic foil 1. 3 denotes a metal foil and contact between the plate 9 and foil 3 is ensured in the manner described above. A layer of glass fibre or the like may be applied on the finished plastic foil to protect the foil and the flooring on top of the foil. The method according to the invention can be varied in many ways within the scope of the appended claims.

Claims: CLAIMS; 1. A method of securing connection tags to electrical conductors in printed circuits in thermal foils and the like in which a contact plate is riveted in place near a hole passing through plastic layers 1, 2 and a metal part 3, characterised in that the contact plate 9 is riveted in place near a hole 4 passing through the plastic layers 1, 2 and a metal foil 3 arranged adjacent to the layers, by means of a rivet, preferably a hollow rivet 6, which is passed through the hole and bent on the opposite side around an upset 8 at the lower edge of the hole, the hole 4 being made with the aid of a mandrel 5, suitably hot and at least partly conical in shape, so that the upper edge of the hole is flanged to a recessed sealing surface for the rivet 6, the central part is formed to an exposed cylindrical metal contact surface 7 against the rivet 6, and the lower side to a sealing upset 8, preferably reinforced at the edge, increasing the contact pressure and hermetically sealing the area around the contact surface. 2. A method as claimed in claim 1, characterised in that between the contact plate 9 and the upper plastic layer 1 a ring 10 with protrusions directed axially downwards is applied, said ring being pressed through the layer into contact with the metal foil during riveting. 3. A method as claimed in claim 2, characterised in that the ring 10 is coated with electrically conducting paint 4. A method as claimed in any of the preceding claims, characterised in that a protective layer of glass fibre, for instance, is applied on the finished thermal foil to protect the thermal foil and to facilitate laying flooring on top of the foil in the case of electrically heated floors, for instance. AMENDED CLAIMS [received by the International Bureau on 16 Apri l 1993( 16.04.93) ; original claims 1 -4 replaced by amended claims 1-4 ( 1 page) ] CLAIMS: 1. A method of securing connection tags to electrical conductors in printed circuits in thermal foils and the like in which a contact plate is riveted in place near a hole passing through plastic layers 1, 2 and a metal part 3, characterised in that the through-hole (4) in the plastic layers (1, 2) is flanged by means of a mandrel (5), suitably hot and at least partly conical in shape, so that the upper edge of the hole is flanged to a recessed sealing surface for the rivet (6), the central part is formed to an exposed cylindrical metal contact surface (7) against the rivet (6), and the lower side to a sealing upset 8, preferably reinforced at the edge, increasing the contact pressure and hermetically sealing the area around the contact surface, and in that the contact plate 9 is riveted in place near the through-hole 4 in the plastic layers (1, 2) and a metal foil (3) arranged adjacent to the layers, by means of a rivet, preferably a hollow rivet (6), which is passed through the hole and bent on the opposite side around an upset at the lower edge of the hole. 2. A method as claimed in claim 1, characterised in that between the contact plate (9) and the upper plastic layer (1) a ring (10) with protrusions directed axially downwards is applied, said ring being pressed through the layer into contact with the metal foil during riveting. 3. A method as claimed in claim 2, characterised in that between the contact plate (9) and the upper plastic layer (1) a ring (10) is applied, said ring being coated with electrically conducting paint and provided with protrusions directed axially downwards, which are pressed through the layer into contact with the metal foil during riveting. 4. A method as claimed in any of the preceding claims, characterised in that a protective layer of glass fibre, for instance, is applied on the finished theπnal foil.

Inventors: KATONA SANDOR, KATONA, SANDOR
Applicants: KATONA SANDOR, KATONA, SANDOR
Application year: 1992
Main classification: H01R4
IPC codes: H01R4, H01R43, H05K1, H05K3