FIELD OF INVENTION
This invention generally relates to an apparatus for Shielded Metal Arc Welding
for carrying out Shielded metal arc welding through narrow gaps available in the
products for example, header joints and boiler-Down comer nozzle joints. More
particularly, the invention relates to an improved electrode holder adaptable to
narrow gap welding applications in the process of manual metal arc welding.
BACKGROUND OF THE INVENTION
Figure - 1 shows a prior art electrode holder adapted for carrying out manual
metal arc welding. The electrode holder comprises a bottom jaw (1), a top jaw
(02) along with a handle, a pair of jaw cover (03) meant one each for both top
and bottom jaws (01, 02), a spring pad (04) mounted on the bottom jaw (03), a
spring cover (05) fixed to the lower side of the handle, a taper plug (06), and a
nut (07) mounted at the rear side of the bottom jaw (01), a holder cover (08)
made of an insulating material, a handle insulation (09), a spring (10), a pin (11)
used for assembling the top jaw to the bottom jaw and screws (12, 13) for fixing
the holder cover (08) to the bottom jaw and for fixing the jaw covers (03) to the
jaws. The electrode holder is generally, having a power connection means where
a welding cable is connected to the electrode holder, and is further having a
clamping facility and a holding facility with which it is held by the welder and an
electrode is finally clamped on the electrode holder for carrying-out the welding.

According to the prior art process for fabrication of steam generator components,
as shown in figure - 3, a number of tubes are welded sequentially on to a
circular pipe in a number of rows. The tubes are placed close to each other.
Since these tubes are in a row and there are a plurality of rows, the gaps
available for the operator to extend his hand and doing the arc welding are
substantially narrow. The welding through a narrow gap becomes more difficult
when the welding needs to be done in the root and throughout. A typical
application of a narrow gap welding is shown in Figure 2, which illustrates a
welding of a down comer nozzle with the shell. Here the welding has to be
carried out in a narrow gap on a product of high thickness. The gap is narrow
and deep. In the existing electrode holder, the holder lever is protruding outside
at an angle. The protrusion of the lever is around 50-80 mm away from the torch
body. Due to this protrusion, the spring is selected to have a bent design which
is also protruding outside. Thus, the lever movement generates a circular path.
Accordingly, the welder has to exert more force to hold the electrode. While
holding the electrode holder, the welder has to insert his hand with gloves, with
much difficulty, between the lever and the electrode bolder body. Because of the
disadvantages, the holding of the electrode holder, entry in to a narrow gap
including visibility inside the narrow gap get obstructed. All these constraints
make it quite impossible to get a sound weld using these conventional electrode
holders. Further, the cycle time required gets extended, and the error rate during
the welding increases. Additionally, a substantially larger length of the electrodes
gets wasted as they can not be fully exploited inside the deep grooves. The

number of start and stop increases which once again lead to more errors. In an
average, in the prior art process of deep root welding, out of 450mm electrode
length, only 230 mm length normally can be made use of.
Hence there is a need to develop an improved welding electrode holder
adaptable to shielded arc welding through the narrow gaps.
OBJECTS OF INVENTION
It is therefore an object of the invention to propose an improved electrode
holder adaptable to narrow gap welding applications in the process of manual
metal arc welding.
Another object of the invention is to propose an improved electrode holder
adaptable to narrow gap welding applications in the process of manual metal arc
welding, which eliminates the disadvantages of prior art increasing reduction in
the wastage of unused electrodes.
Yet another object of the invention is to propose an improved electrode holder
adaptable to narrow gap welding applications in the process of manual metal arc
welding, which enhances the comfort level of the operator including quality of
welding and production cycle.

SUMMARY OF INVENTION
Accordingly, there is provided an improved welding electrode holder adaptable to
narrow gap welding applications in the process of manual metal arc welding,
comprising an electrode holder body including a bottom jaw forming a first single
component a metallic lever including a top jaw forming a second single
component; the electrode holder body comprising a first through hole, and the
metallic lever having a second through hole, a holding means being inserted
between the first and the second through holes enabling alignment and
synchronized play of the electrode holder. The electrode holder further
comprising a first blind hole configured at a location constituting a middle
position of the holder body of the first single component, wherein a second blind
hole correspondingly configured on the second single component, the first blind
hole being adapted for accommodating a modified spring retainer to allow
mounting a modified compression spring, wherein the second blind hole
accommodating a modified spring retainer to allow mounting of the modified
compression spring; and a modified taper plug disposed on the bottom jaw body,
a modified fastening means provided for connecting the welding cable with the
electrode holder such that an electrode is held between the upper and lower
jaws by the force of the compression spring.
The lever of the improved electrode holder has a shape that reduces the
protrusion of the lever from the holder body, thus making the holder suitable for
narrow gap welding.

The electrode holder of the invention enables the welder to burn maximum
length of electrode, thus minimizing the electrode, reducing the number of starts
and hence ensuring defect free weldments.
The holder cover fixed to the holder body, has a slot which enables the operator
to press down the lever even below the surface level of the holder cover.
The axis of the compression spring disposed between the lever and the holder
body is straight facilitating exertion of a small force to open the jaws-by the lever
for inserting the electrodes.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
1. Figure - 1 Shows an electrode holder of prior art.
2. Figure - 2 Schematically illustrates a prior art process of welding a down
comer nozzle to a shell.
3. Figure - 3 Schematically illustrates a typical process of Header Stubs
welding.
4. Figure - 4 Shows an improved electrode holder with modified handle for
narrow gap welding according to the invention.

5. Figure - 5 Shows a modified lever of the improved electrode holder of
Figure - 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the invention as shown in Figure - 4, the proposed electrode holder
comprises an electrically conducting electrode holder body integral with a bottom
jaw (01). A metallic lever and a top jaw (02) forming a single component. The
jaws (01, 02) have positioning seats for the electrodes. The middle part of the
electrode holder body has a holding means (15) consisting of a hole and a
metallic pin (15) for aligning the top jaw lever (02). The metallic pin (15) is
inserted into a first through hole on both sides of the electrode holder body and
into a second through hole on the metallic lever (02). Atleast two non-metallic
jaw covers (03) are fixed, one each on the top and bottom jaws (01, 02) through
a first pair screws (14). A non-metallic holder cover (08) is fixed to the holder
body using a second pair of screws (16). Exactly at the center of the holder
body, there is a first blind hole for mounting a modified compression spring (17).
This spring (17) is mounted on a modified spring retainer (8) placed on the
bottom jaw body (01). At the center of the top jaw lever (02), there is a second
blind hole for mounting the modified compression spring (17) by placing a
modified spring retainer (18). The top jaw lever (02) further is covered by an
additional non-metallic jaw cover (21) for giving proper insulation. At the right
hand side of the electrode holder, in the bottom jaw body (01), a modified taper

plug (19) and a modified hexagonal nut (20) are used for gripping a welding
cable for connectivity. The electrode is held between the upper and lower jaws
(01, 02) by the force of the compression spring (17).
In this modified design, the gap (H2) between the lever and the holder body has
been reduced by atleast 50% compared to the gap (HI) of prior art: electrode
holder. The protrusion of the lever in this modified electrode holder is only
around 30 to 35 mm including the thickness of the lever, and 20 to 25 mm
without considering the lever thickness. The lever (02) runs parallel to the
electrode holder body. So, the welder is able to easily press the lever (02) and
set the electrodes only with the palm pressure. They need not exert more
energy. The lever (02) goes inside the palm of the welder. So it is very easy for
him to handle the electrode. Since the modified electrode holder is under the
control of the welders palm, there is no obstruction for clear visibility and ease of
accessibility to the deep root of the weld. It becomes easy to get sound welds.
Due to ease of visibility and accessibility, the number of start and stops are
eliminated. A substantially full length of the electrode burning is ensured in a
single start and stop. The stub length at present with this modified design is
around 60mm. Because of unhindered smooth process of welding, the cycle time
is much reduced; production is highly enhanced. Weld repairs are also reduced
to minimum.

WE CLAIM
1. An improved welding electrode holder adaptable to narrow gap welding
applications in the process of manual metal arc welding, comprising :
- an electrode holder body including a bottom jaw (01) forming a first single
component;
- a metallic lever including a top jaw (02) forming a second single
component;
- the electrode holder body comprising a first through hole, and the metallic
lever having a second through hole, a holding means (15) being inserted
between the first and the second through holes enabling alignment and
synchronized play of the electrode holder; characterized by comprising;
- a first blind hole configured at a location constituting a middle position of
the holder body of the first single component (01), wherein a second blind
hole correspondingly configured on the second single component (02), the
first blind hole being adapted for mounting a modified compression spring
(17), wherein the second blind hole accommodating a modified spring
retainer (18) to allow mounting of the modified compression spring (17);
a modified taper plug (19) disposed on the bottom jaw body (01), and a
modified fastening means (20) provided for connecting the welding cable
with the electrode holder such that an electrode is held between the

upper and lower jaws (01, 02) by the force of the compression spring
(17).
2. The electrode holder as claimed in claim 1, wherein the top and bottom
jaws (02, 01) each comprising jaw covers (03) respectively and fixed
thereon via a first pair of screws (14).
3. The electrode holder as claimed in claim 1 or 2, wherein a holder cover
(08) is fixed on the holder body (01) via a second pair of screws (14).
4. The electrode holder as claimed in any of the preceding claims,
comprising an additional jaw cover (21) provided for the top jaw lever
(02), and wherein the additional jaw cover (21) is insulated.
5. The electrode as claimed in any of the preceding claims, wherein the
protrusion of the lever within the electrode holder is maintained between
30 to 35 mm.
6. An improved welding electrode holder adaptable to narrow gap welding
applications in the process of manual metal arc welding, as substantially
described and illustrated herein with reference to the accompanying
drawings.

The invention relates to an improved welding electrode holder adaptable to narrow gap welding applications in the process of manual metal arc welding, comprising an electrode holder body including a bottom jaw (01) forming a first
single component; a metallic lever including a top jaw (02) forming a second single component; the electrode holder body comprising a first through hole, and the metallic lever having a second through hole, a holding means (15) being
inserted between the first and the second through holes enabling alignment and synchronized play of the electrode holder; a first blind hole configured at a location consisting the middle position of the holder body of the first single component (01), wherein a second blind hole corresponding configured on the second single component (02), the first blind hole accommodating a modified spring retainer (18) for mounting a modified compression spring (17), wherein the second blind hole accommodating a modified spring retainer (18) allowing the mounting of the modified compression spring (17); and a modified taper plug (19) disposed on the bottom jaw body (01), and a modified fastening means (20) provided for connecting the welding cable with the electrode holder such that an electrode is held between the upper and lower jaws (01, 02) by the force of the compression spring (17).