TH23015B - Method for connecting spiral coiled pipes - Google Patents

Abstract

DC60 (16/03/47) This invention describes a method for joining thermoplastic pipes (1) made by spiraling a hollow outline (2) with a predominantly rectangular cross-section. The procedure is characterized by the following steps: cutting the outline (2) at the ends of the pipe along the inside of the side wall, which is then bonded to the nearest rounded edge and to a section (3) that cuts the ends of the outline at a right angle or an obtuse angle (a) of equal size for all ends of the pipes to be joined together; closing the hole in the cut end (3) of the outline and preparing the end surfaces of the pipes along all the rounded edges; positioning the two pipes (1) of their aligned counterparts so that the ends of the cut outline (3) overlap axially; inserting a connecting ring (5) that fits the inner diameter and The outer side of the tube, between two tubes (1), by a welding ring consisting of at least one loop of resistance wire (8) covered by a thermoplastic sheath (7), the alignment of the two tubes (1) with inner root supports (8) and outer root supports (9) around the seam by a welding ring (5), the pressing of the tube ends together, the connection of the resistance wire (6) of the welding ring to a current source (12) to heat the thermoplastic material in the welding ring (5) and in the tube ends to melt the thermoplastic material and create a weld seam, the cooling of the weld seam, the removal of the root supports (8, 9) and other accessories (10, 11) from the welded tubes, and the cutting of the welding ring's connecting wire (13) (Figure 1). This invention describes a method for joining thermoplastic tubes (1) made by spiraling a hollow outline (2) with a predominantly rectangular cross-section. The procedure is characterized by the following steps: Outline cutting. (2) At the ends of the pipes, along the inside of the side walls, which are bound to the nearest rounded edge and to the section (3) that cuts the ends of the outline at a right angle or an obtuse angle (a) of equal size for all the ends of the pipes which are to be welded together, closing the holes in the cut ends (3) of the outline and preparing the end surfaces of the pipes along all the round edges, positioning the two pipes (1) of them that are aligned with each other. To overlap the ends of the cut outline (3) axially, a welding ring (5) is inserted, fitting the inner and outer diameters of the tube between the two tubes (1), with the welding ring consisting of at least one resistance wire (8) covered by a thermoplastic sheath (7), the two tubes (1) are aligned with the inner root supports (8) and outer root supports (9) around the seam with the welding ring (5), the ends of the tubes are pressed together, the resistance wire (6) of the welding ring is connected to a current source (12) to heat the thermoplastic material in the welding ring (5) and in the tube ends, causing the thermoplastic material to melt and form the weld seam, the weld seam is cooled, the root supports (8, 9) and other accessories (10, 11) are removed from the welded tubes, and the welding ring's connecting wire (13) is cut.

Claims (14)

1. The method for joining thermoplastic tubes (1) is made by coiling a hollow outline (2) with a predominantly rectangular cross-section, where the ends of the thermoplastic tubes are prepared by closing the end openings of the hollow outline so that the tubes receive uniformly stepped end faces. After the tubes to be joined are aligned to each other, where the preparation of the tube ends consists of cutting the outline (2) at the ends of the tubes along the inner side of the side wall, which is secured to the nearest preceding coil, resulting in a double-walled end face, and cutting the ends (3) of the outline with a right-angled or obtuse (alpha) cross-section of equal size for all the ends of the tubes to be joined together. A disc-shaped welding ring (5) that fits the inner and outer diameters of the tubes is inserted into the gap between the two tubes (1), in which the welding ring consists of at least one loop of resistance wire (6). Covered with a thermoplastic sheath (7), two tubes (1) are concentrically joined with an inner root support (8) and an outer root support (9) around the seam with a welding ring (5). The ends of the tubes are pressed together and sealed. A resistance wire (6) of the welding ring is connected to a current source (12) to heat the thermoplastic material in the welding ring (5) and the ends of the tubes, causing the thermoplastic material to melt and form a weld seam. The weld seam is cooled, the root supports (8, 9) and other accessories (10, 11) are removed from the joined tubes, and the connecting wire (13) of the welding ring is cut off. 2. The method under claim 1 is characterized by the angle (alpha) at which the outline ends are cut equal to 135°C. 3. The method under claim 1 is characterized by the angle (alpha) at which the outline ends are cut equal to 150°. 4. The method according to claim 1 is made special in that the closure of the hole in the end of the outline (3) is carried out by welding a plastic sheet (15) onto the end of the cut outline (3). 5. The method under claim 4 is characterized by the concave inner corner between the cut end of the outline (3) and the plastic sheet (15) and the end surface of the tube being fed with an extruded thermoplastic mass, and the convex outer corner between the plastic sheet (15) and the end surface of the tube being rounded to a certain degree. 6. The method under claim 1 is made special in that the weld ring (5) is flexible and fits the prepared end face shape of the pipe end when the pipe ends are pressed together. 7. The method under claim 1 is made special in that the weld ring (5) is pre-bent between two pressing plates (19) to the same shape as the ends of the pipes to be welded together. 8. The method under claim 1 is made special in that the pipes (1) are not only compressed together by the force which compresses them, but are also subjected to torsional force so that they are compressed between the ends of the cut outline (3) of the pipe ends. 9. The method according to claim 1 is characterized as follows: the weld ring (5) is produced by pressing out a thermoplastic sheath (7) around a painted resistance wire (6), and by winding the thermoplastic-covered resistance wire (6) into a spiral on a removable coiled tube core (16), by which its core has a diameter corresponding to the inner diameter of the tube (1) and a length corresponding to the width of the thermoplastic sheath (7), and its wings (7) are arranged with radially directed slots (18), by which the spiral sections wrapped around the edges of the weld ring (5) are welded together by a weld through them. 10. The method according to claim 9 is made special in that the connecting wire (13) of the welding ring (5) is drawn either to the outer or inner edge of the welding ring (5). 11. The method under claim 9 is made special in that the connecting ring (5) is assembled by coiling a resistance coil (6,6a) covered with two thermoplastics in a simultaneous spiral on a removable coil core (16). 12. The method according to the right 11 is made special in that one pair of ends of the resistance wire (6,6a) is joined by a coupling method (20) and the opposite pair of ends can be connected to a current source (12). 13. The method under claim 9 is made special in that the resistance wire (6) covered with thermoplastic is folded in two before being coiled on a removable coil core (16). 14. The method according to the information provision 9 is characterized in which the welding ring (5) is coiled by the inner and outer radial outline loops (6), with its connecting wire being brought to the inner and outer edges of the welding ring (5), respectively.