Title of Invention

DEVELOPMENT OF STRIP ELECTRODE GAS METAL ARC WELDING

Abstract Accordingly, there is provided an integrated apparatus for continuous forming of flat strip from standard MIG welding wire and feeding the strip electrode via a modified torch with corresponding contact tip for GMAW. The apparatus also serves as strip wire feeder and feeds the strip through the modified torch. The contact tube of the torch is so designed to allow feeding of consumable strip electrode.
Full Text 2 FIELD OF INVENTION
The invention generally relates to an apparatus and process adaptable to Gas Metal Arc Welding (GMAW), which gives higher deposition rate, improved gap bridge-ability, higher welding speed and better weld quality. More particularly, the invention relates to an integrated apparatus for continuous forming of flat strip from standard MIG welding wire and feeding the strip electrode via a modified torch with corresponding contact tip for GMAW.
BACKGROUND OF INVENTION
There has been a continuous demand for newer welding processes and techniques with improved productivity, better quality in order to bring down the cost of welding. It was demands such as these, which prompted the development of high-performance welding processes with enhanced wire feed speeds and deposition rates. A process is regarded as a "high-performance" welding process if it achieves a deposition rate more than 8 kg/h.
"Tandem" MIG welding is one such high performance MIG welding technique developed to achieve higher productivity. It involves feeding of two electrode wires through the same torch, thus creating two arcs acting on the same weld pool and melting off simultaneously. Though, the tandem MIG gives higher deposition rate and welding speed, there are problems with guiding the torch along curved welding seams, as the geometrical relative positions of the leading and trailing wires have to be maintained with respect to the direction of welding.

3
A relatively new approach to improve the performance of GMA welding is the use of flat strip-wires, which achieves higher deposition rates compared to that of the tandem MIG. The advantages of strip electrode GMA welding over the tandem welding are that, firstly, it requires only one power source, and secondly, setting the welding parameters in this process is considerably easier.
Strip-wire electrodes are produced either by additional rolling of round wires, or by slitting wide strips. Rolled strip-wires have rounded edges, while slit strip-wires tend to be sharp edged. From the wire feed point of view, the, rolled strip-wires are preferable.
However, winding the strip electrode on standard welding spool is difficult and feeding the electrode entails problem due to twisting of the strips.
OBJECTS OF INVENTION
It is therefore an object of the invention to propose an integrated apparatus for continuous forming of flat strip from standard MIG welding wire and feeding the strip electrode via a modified torch with corresponding contact tip for GMAW.
Another object of the invention is to propose an integrated apparatus for continuous forming of flat strip from standard MIG welding wire and feeding the strip electrode via a modified torch with corresponding contact tip for GMAW which ensures consistent transfer of the current from a known power source to the strip electrode wire.

4
A further object of the invention is to propose an integrated apparatus for continuous forming of flat strip from standard MIG welding wire and feeding the strip electrode via a modified torch with corresponding contact tip for GMAW which eliminates the disadvantages of the prior art of forming strip-wire electrodes.
These and other objects and advantages of the invention will be apparent from the ensuing description.
At the outset of the description, which follows, it is to be understood that the ensuing description only illustrates a particular form of this invention. However, such a particular form is only an exemplary embodiment and the teachings of the invention are not intended to be taken restrictively.
SUMMARY OF THE INVENTION
Accordingly, there is provided an integrated apparatus for continuous forming of flat strip from standard MIG welding wire and feeding the strip electrode via a modified torch with corresponding contact tip for GMAW. The apparatus also serves as strip wire feeder and feeds the strip through the modified torch. The contact tube of the torch is so designed to allow feeding of consumable strip electrode.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Figure 1 - Shows an embodiment of the apparatus according to the invention.

5
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Referring now to the drawing, wherein like reference numerals designate identical or corresponding parts throughout the several views. Figure 1 shows the schematic of the integrated apparatus adaptable to Gas Metal Arch Welding system. In this apparatus, a standard MIG welding wire (1) available in 300 mm diameter spool (2) is fed through a guide tube (3) and then it is converted into a flat strip (4) by a rolling cum feeding means (5). The flat strip (4) thus formed is fed through a torch (6). The torch (6) incorporates a contact tube (7) to allow feeding of the strip electrode (4). A standard Constant Voltage type power source (8) is used with reverse polarity connection.
Therefore, the present invention ensures online conversion of the standard MIG welding wire (1) into continuous strip (4) and feeding the strip wire (4) through a modified torch (6) eliminating the need for winding the wire (6) in a separate spool. The torch (6) is specifically modified for feeding strip electrode (4).
The invention further provides an improved torch (6) with a contact tip (7) for accommodating the strip electrode wire (4).
The advantages of the invention can be seen, inter alia, in the fact that the strip electrode wire (4) is fed smoothly through the modified contact tube (7) and a stable arc is produced resulting in good weld bead at higher welding speed and deposition rate.

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The welding system converts a standard 2.0 mm diameter MIG wire (1) into a flat strip (4) and also feeds the strip (4) through the torch (6). A contact tube (7) is designed to allow feeding of strip electrode (4).

7 We Claim
1. An integrated apparatus for continuous forming of flat strip from standard
MIG welding wire and feeding the strip electrode via a modified torch with
corresponding contact tip for GMAW, the apparatus comprising:
- a spool (2) having standard MIG welding wire (1);
- a guide tube (3) for feeding the MIG welding wire (1); and
- a rolling-cum-feeding means (5) for converting the MIG standard
wire (1) into flat-strip wire (4) and simultaneously feeding the flat
strip wire (4) via a modified torch (6), the torch (6) having a
copper contact tube (7) so configured to allow feeding of the strip
wire (4).

2. The apparatus as claimed in claim 1, comprising a constant voltage type
power source (8) with reverse polarity connection.
3. An integrated apparatus for continuous forming of flat strip from standard
MIG welding wire and feeding the strip electrode via a modified torch with
corresponding contact tip for GMAW as substantially herein described and
illustrated with the accompanying drawing.

Accordingly, there is provided an integrated apparatus for continuous forming of flat strip from standard MIG welding wire and feeding the strip electrode via a modified torch with corresponding contact tip for GMAW. The apparatus also serves as strip wire feeder and feeds the strip through the modified torch. The contact tube of the torch is so designed to allow feeding of consumable strip electrode.

Documents:

00173-kol-2007-correspondence.pdf

00173-kol-2007-form-18.pdf

0173-kol-2007-abstract.pdf

0173-kol-2007-assignment.pdf

0173-kol-2007-claims.pdf

0173-kol-2007-correspondence others.pdf

0173-kol-2007-description (complete).pdf

0173-kol-2007-form1.pdf

0173-kol-2007-form2.pdf

0173-kol-2007-form3.pdf

173-KOL-2007-ABSTRACT.1.1.pdf

173-KOL-2007-AMANDED CLAIMS.pdf

173-KOL-2007-AMANDED PAGES OF SPECIFICATION 1.1.pdf

173-KOL-2007-AMANDED PAGES OF SPECIFICATION.pdf

173-KOL-2007-CORRESPONDENCE 1.1.pdf

173-KOL-2007-CORRESPONDENCE.1.3.pdf

173-KOL-2007-CORRESPONDENCE.pdf

173-KOL-2007-DESCRIPTION (COMPLETE).1.1.pdf

173-KOL-2007-DRAWINGS 1.1.pdf

173-KOL-2007-DRAWINGS.pdf

173-KOL-2007-EXAMINATION REPORT.1.3.pdf

173-KOL-2007-EXAMINATION REPORT.pdf

173-KOL-2007-FORM 1.1.1.pdf

173-KOL-2007-FORM 18.1.3.pdf

173-KOL-2007-FORM 18.pdf

173-KOL-2007-FORM 2.1.1.pdf

173-KOL-2007-FORM-27.pdf

173-KOL-2007-GPA.1.3.pdf

173-KOL-2007-GRANTED-ABSTRACT.pdf

173-KOL-2007-GRANTED-CLAIMS.pdf

173-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

173-KOL-2007-GRANTED-DRAWINGS.pdf

173-KOL-2007-GRANTED-FORM 1.pdf

173-KOL-2007-GRANTED-FORM 2.pdf

173-KOL-2007-GRANTED-LETTER PATENT.pdf

173-KOL-2007-GRANTED-SPECIFICATION.pdf

173-KOL-2007-OTHERS.pdf

173-KOL-2007-REPLY TO EXAMINATION REPORT.1.3.pdf

173-KOL-2007-REPLY TO EXAMINATION REPORT.pdf

abstract-0173-kol-2007.jpg


Patent Number 247481
Indian Patent Application Number 173/KOL/2007
PG Journal Number 15/2011
Publication Date 15-Apr-2011
Grant Date 11-Apr-2011
Date of Filing 05-Feb-2007
Name of Patentee BHARAT HEAVY ELECTRICALS LIMITED
Applicant Address REGIONAL OPERATIONS DIVISION (ROD), PLOT NO: 9/1,DJBLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091 HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT NEW DELHI-110049 INDIA
Inventors:
# Inventor's Name Inventor's Address
1 ARASAN RAJA WELDING RESEARCH INSTITUTE, BHEL, TIRUCHY-620014
2 MARIMUTHU SAMIDURAI WELDING RESEARCH INSTITUTE, BHEL, TIRUCHY-620014
3 KANHAIYALAL ROHIRA WELDING RESEARCH INSTITUTE, BHEL, TIRUCHY-620014
PCT International Classification Number B23K9/173,B23K35/02
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA