Title of Invention

APPARATUS FOR WELDING CYLINDRICAL ELEMENTS AND TOROIDAL BODIES

Abstract

The invention relates to an apparatus for welding cylindrical elements and toroidal bodies, said apparatus comprising a base (13), an electrode adaptor (14), having a welding electrode (15) attached thereto, a fitting member (1) which is mounted on the base (13) and has the rotatably bearing-mounted electrode adaptor (14) extended therethrough, and a shielding gas chamber (3), which is dismountably mountable on the fitting member (1), around the electrode (15). The shielding gas chamber's (3) accommodation space for elements or bodies (A, B) to be welded is designed in such a way that the elements or bodies (A, B) to be welded constitute a section of the walls defining the shielding gas chamber's (3) gas space and further constitute a partition for dividing the shielding gas chamber for two chamber compartments, one of which, an inner chamber, directs the shielding gas to the interior of the elements or bodies to be welded and the other, an outer chamber (5, 5.1, 5.2), surrounds the eventual weld.

Full Text

Apparatus for welding cylindrical elements and toroidal bodies The invention relates to an apparatus for wdding cylindrical elements and toroidal bodies, said apparatus comprising - abase, - an electrode adaptor, having a welding electrode attached thereto, - a fitting member, which is mounted on the base and has the rotatably bearing-mounted electrode adaptor extended therethrough, and - a shielding gas chamber, which is dismountably mountable on the fitting member, around the electrode This type of welding apparatus is known from the Applicant's published international application WO 99/55486 and from the corresponding patent publication US-6,433,307 Bl. This prior known combination of a welding apparatus and a shielding gas chamber Is described to Include a blocked shielding gas chamber, wefl adapted to welding relatively short pipes. As for welding long pipes, the arrangement is no longer practical. It is an object of the invention to provide an alternative solution, which is also applicable to the welding of long pipes. This object is accomplished on me basis of characterizing features as set forth in the appended claim i. Preferred implementations of the invention are disclosed In the dependent claims. One exemplary embodiment of the invention will now be described in more detail with reference to the accompanying drawing, in which: Rg. 1 shows a welding apparatus of the invention in an axial section, and Fig. 2 shows in an axonometric view a shielding gas chamber included In a welding apparatus of the Invention. The apparatus comprises a schematically depicted base 13 and an electrode adaptor 14, reference being made to the dted international application WO 99/55486 and the patent US-6,433,307 regarding its drive mechanism. The electrode adaptor 14 is provided at least with a rotary drive and, in a preferred case, also with a reciprocating axial motfon, controlled in a manner dependent on the rotary drive. The base 13 is provided with a fitting member 1, having the electrode adaptor 14 extended therethrough. The electrode adaptor 14 is mounted with bearings 2 dietectrically on the fitting member 1. The actual welding chamber for welding long pipes, mains and branches of bypass manifolds is constituted by a component 3. The shielding gas chamber 3 is dismountabiy mountabte on the fitting member 1 around an electrode 15. For this purpose, the fitting member 1 is provided with an inner cylinder ic concentric with the electrode adaptor 14 and the shielding gas chamber 3 is provided with a protruding cylinder element 3cr sized to provide a push fit with the inner cylinder ic. The protruding cylinder element 3c is internally sized to accept a branch pipe B to be welded and the shielding gas chamber 3 is provided with a recess, which is complementary to a main pipe A and which is blocked outwards by the main pipe A. The recess diverges or expands within the range between the blocking point and the cylinder element 3c to define a blocking-point surrounding outer chamber 5, 5.1,5.2 for shielding gas. The elements A and B are sized or dimensioned, such that the main pipe's A major diameter coincides with the outer chamber's 5, 5.1 inner edge to define a smallest possible clearance. At a junction between the main pipe A and the branch pipe 8, i.e. at a weld, the outer chamber 5, 5.1 surrounds the branch pipe B and, at the same time, surrounds the entire weld joint In its lower part, the outer chamber is divided for two compartments 5.1 and 5,2 by means of an element 6 providing a laminar gas flow. As the shielding gas chamber's 3 cylinder element 3c is sized to provide a push fit with the fitting member's 1 inner cylinder, the centre axes of elements to be welded will coincide with the extension of the electrode adaptor's 14 centre axis upon pushing the elements 1,3 within one another, as regards the cylinder portions Ic, 3c thereof. The electrode 15 is secured to the electrode adaptor 14 in a centralized manner and the electrode 15 has its length set at a wdding distance from the junction of the elements A and B, resulting in a welding assembly ready for service. A shielding gas needed In welding is guided inside a body to be welded through a hole 9 and further from the outer end of the branch pipe B to the interior of the branch pipe B, The gas fiiis the inner chamber space and propels the existing inside air out through the main pipe A, The shielding gas external of a weld is delivered through a hole 8 along a pipe 7 into the compartment 5.2, from which the gas progresses in a laminar flow into the compartment 5.1 and 5. The afr, which is propelled ahead of gas, and the gas, which is used during the process, discharge through a hole 4 and by way of gaps between the pipe A and the element 3. The pipe 7 and the hole present in the element 3 are sized In such a way that the pipe 7 functions as a guide to set the elements 1 and 3 always in the same relative position. Retention of the pipe sections A and B, as well as the shielding gas chamber 3 in the same relative position throughout a welding process is secured by means of fastening elements 10,11 and 12. A screw 12 can be used for damping the elements to a position blocking the shielding gas chamber 3. What is essential in the invention is that the elements or bodies to be welded constitute a part of the walls defining a shielding gas chamber and at the same time divide Hie shielding gas chamber for inner and outer compartments. Thus, the shielding gas spaces remain very small, yet the size of elements to be welded and especially the length of the main pipe A are not limited. "fine invention is not limited to the above-described exemplary embodiment as the design and sizing of elements cart be modified in a variety of ways. For example, the shielding gas chamber 3 may consist of a plurality of sections, tfte attachment of which to each other is achieved by means of elements to be welded. In this case, at least one chamber sectton is used to support and align the elements to be welded relative to each other. We claim: 1. An apparatus for welding cylindrical dements and toroidal bodies, said apparatus comprising - a base (13), - an electrode adaptor (14), having a welding electrode (15) attached thereto, - a fitting member (1), which is mounted on the base (13) and has the rotataoiy bearing-mounted electrode adaptor (14) extended therethrough, and - a shielding gas chamber (3), which is dismountabty mountable on the fitting member (1), around the electrode (IS), characterized in that the shielding gas chamber's (3) accommodation space for elements or bodies (A, B) to be welded ts designed in such a way that the elements or bodies (A, B) to be welded constitute a section of the wails defining the shielding gas chamber's (3) gas space and further constitute a partition for dividing the shielding gas chamber for two chamber compartments, one of which, an inner chamber, directs the shielding gas to the interior of the elements or bodies to be welded and the other, an outer chamber (5, 5.1, 5,2), surrounds the eventual weld. 2. An apparatus as set forth in claim 1, characterized in that the fitting member (1) is provided with an inner cyfinder (Ic) concentric with the electrode adaptor (14) and the shielding gas chamber (3) is provided with a protruding cylinder etement (3c) sized to provide a push fit with the Inner cylinder (Ic), 3. An apparatus as set forth in claim 2, characterized in that the protruding cylinder element (3c) is internally sized to accept a branch pipe (B) to be welded and the shielding gas chamber is provided with a recess, which is complementary to a main pipe (A) and which is blocked outwards by the main pipe (A), which recess diverges within the range between said blocking point and the cylinder element (3c) to define said outer chamber (5, S.I, 5.2), 4. Art apparatus as set forth In any of daims 1-3, characterized in that between the fitting member (1) and the shielding gas chamber (3) Is a shielding gas pipe (7), which connects to the outer chamber (5, 5.1, 5.2) and which functions as a guide to set the fitting member (1) and the shielding gas chamber (3) always in the same relative position. 5. An apparatus as set forth In any of daims 1-4, characterized fn that the shielding gas chamber (3) is provided with fastening means (10-12) for securing the elements or bodies (A, B) to be welded in a position blocking the shielding gas chamber (3).

Documents:

4998-delnp-2005-abstract.pdf

4998-delnp-2005-claims.pdf

4998-delnp-2005-correspondence-others.pdf

4998-delnp-2005-description (complete).pdf

4998-delnp-2005-drawings.pdf

4998-delnp-2005-form-1.pdf

4998-delnp-2005-form-18.pdf

4998-delnp-2005-form-2.pdf

4998-delnp-2005-form-26.pdf

4998-delnp-2005-form-3.pdf

4998-delnp-2005-form-5.pdf

4998-delnp-2005-pct-237.pdf

4998-delnp-2005-pct-301.pdf

4998-delnp-2005-pct-304.pdf

4998-delnp-2005-pct-308.pdf

4998-delnp-2005-pct-311.pdf

4998-delnp-2005-pct-373.pdf

4998-delnp-2005-pct-request form.pdf

4998-delnp-2005-pct-search report.pdf