Title of Invention

SPECIAL FIXTURE FOR MANUFACTURING OF SEAL WIRE TO BE USED IN FIXING ROOTS OF GAS TURBINE BLADE

Abstract This invention relates to a special fixture for manufacturing of seal wire used in fixing roots of gas turbine blades comprising a pair of special clamps(7)fixed in a block(1),the said clamps are operated by means of pins(12)and spring(9)to hold a job(J)in agroove(G)and are adapted to move vertically up and down and rotatable left and right hand side to grip the job in the groove axially or in inclined position and milling the job to form a groove or or portrusion in it to form a seal wire for the fixing roots of gas turbine blade, the said fixture being additionally arranged with a top clamp(2)in case of high speed feed and deep cut requirement,wherein the resultant force(F)of the clamping grip of the job acts at an angle from the horizontal line, thus enhancing grip on the job through division of the acting (F)into horizontal and downward vertical directions and thus preventing any slippage of the job.
Full Text -2-
FIELD OF INVENTION
This invention relates to development of a special fixture for manufacturing of seal wire used in fixing roots of gas turbine blades. More specifically the present invention relates to modification of special fixture employed to manufacture the seal wire by milling operation.
BACKGROUND OF THE INVENTION
In a gas turbine stationary nozzles discharge jets of expanded gas, usually products of combustion, against the blades of a turbine wheels. To maintain appropriate mechanical energy in a gas turbine to be converted into electrical energy the root of the blades require proper sealing by seal wires. Such seal wires are prepared by milling of round bar.

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In the existing art the round job is held tightly in jaw of parallel vice and milling operation is performed to achieve the desired shape. This process is crude and the desired shape within desired tolerance is very difficult to achieve. As a consequence the job rejection rate is very high due to high risk of slippage of the job falling out of vice and also the seal wire cannot be milled properly within the tolerance limit to prepare the seal wire with desired shape and accuracy of dimensions. The said process therefore is thus time consuming and more material consuming and therefore is not practicable for industrial use.
One of the disadvantage of the existing art is that during milling operation more than half of the diameter of the round job is taken under the parallel vice holding device for safe gripping. So size after milling operation is more than half diameter of the job, as there will be a clearance between the cutter and vice to avoid cut mark on a device.

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The following disadvantages in milling of a round job will occur when the job is held in parallel holding device by taking half of the diameter of the job.
d) clamping will not be proper as the vice will not be capable of gripping
safely and there will be slippage of the job to cause accident.
e) Slippage of job causes rejection of job material.
0 A taper of 0.5 will appear lengthwise after milling operation.
The present invention proposes to remove the above disadvantages of prior art by charging the mode of parallel vice and with provision of a special fixture.
DESCRIPTION OF THE INVENTION
The main objective of the invention is to develop fixture for round job wherein the clamping force acts at an angle from horizontal line instead of parallel gripping. The angular clamping force is divided into two-component force in horizontal and vertical direction thus enhancing the grip and preventing the job from coming out of the fixture.

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Another objective of the invention is to fix a top clamp on the fixture to increase productivity, enhance further safety.
A still another objective of the invention is to develop clamps of various types and dimensions in the fixture which permits safe milling of any round job having diameter less than or greater than 12 mm by easily charging the different types of special clamp.
A still further objective of the invention is to develop a cost effective special fixture with special clamps.
According to the invention there is provided a special fixture for manufacturing of seal wire used in fixing roots of gas turbine blades comprising: a pair of special clamps fixed in a block, the said clamps are operated by means of pins and spring to hold a job in a groove and are adapted to move vertically up and down and rotatable left and right hand side to grip the job in the groove axially

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or in inclined position and milling the job to form a groove or portrusion in it to form a seal wire for the fixing roots of gas turbine blade, the said fixture being additionally arranged with a top clamp in case of high speed feed and deep cut requirement, wherein the resultant force of the clamping grip of the job acts at an angle from the horizontal line, thus enhancing grip on the job through division of the acting force into horizontal and downward vertical directions and thus preventing any slippage of the job.
The present invention will be better understood by the following description with reference to the accompanying drawings in which
Figure 1 represents the acting force by parallel vice of the existing art; when the grip is held less than half of the diameter of the job.
Figure 2 represents another case of the acting force by parallel vice of the existing art, when the grip is held less than half of the diameter of the job.

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Figure 3 represents the acting force of the grip of the clamps at an angle from the horizontal line according to the present invention.
Figure 4 represents the (a) plan view (b) elevationaf view
(c) side view and (d) end view of the fixture for seal wire according to the present invention.
Figure 5 represents the (a) plan view (b) elevational view and (c) end view of the base block body of the fixture
developed according to the present invention.
Figure 6 represents (a) plan view (b) elevational view, (c) end view of top clamp of the fixture according to the present invention.
Figure 7 represents (a) elevational view (b) plan view and (c) cross sectionaf elevationa! view with end view of the key of the fixture attached to the base of the fixture of the present invention.

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Figure 8 represents (a) elevational view (b) plan view of the top clamp screw of the fixture of the invention.
Figure 9 represents (a) elevational (b) plan views of the special clamp of the fixture according to the invention.
Figure 10 represents (a) elevational and (b) side views of the stopper of the fixture according to the invention.
Figure 11 represents (a) actual view (b) plan view of the special washer of the fixture of the invention.
Figure 12 represents an embodiment of the seal wire prepared with male and female parts from a round job of 12 mm diameter.
Figure 13 represents an isometric view of the fixture according to the invention.

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The disadvantages associated with the parallel grip of the round job and the seal wire to be prepared within the tolerance limit has been shown in Figure 1 and 2.
In the existing art if the operator has to make a thickness as (d/2 + 0.1) - 0.2, where d = diameter of a rod, by milling operation, when the round job is held in parallel vice, more than half of the diamter (d/2 + 0.5) is taken under the holding device for safe gripping. So size after milling operation is more than (d/2 + 0.5) as there should be clearance between a cutter and vice to avoid cut mark on a device.
If the round bar is held by taking less than half of the diameter of a job in parallel holding device, the operation will have to face the following adverse
situations.
As shown in Figure 1 gripping will be safe if clamping force passes through axis of cross-section circular area of the round bar. As less than half of the diameter
is taken under vice, clamping would not be proper, vice is not capable of gripping safely as there is definitely slippage of job that causes accident.

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Figure 2 shows another case of gripping of less than half the diameter of a job.
Both in the case of positions of the grips result in slippage of a job, causes rejection of job material and a taper of 0.5 appears lengthwise after milling operation.
Figure 3 shows clearly the inventive concept of the present invention wherein resultant force (F) of the damping grip of the clamps acting at an angle from horizontal line is divided into vertical and horizontal component. The horizontal component provides a horizontal grip of the job and the vertical component acts vertically downward direction to further enhance the grip and at the same time secure the job from any slippage out of the fixture thus preventing any chance of accident and wastage of job material from damage due to slippage and at the same time saving wastage of time after mounting the job in the assembled fixture to hold the job.

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In Figure 3, numeral (4) shows the groove through which the job is to be entered and gripped by the angular grip. This groove (5) according to the concept of the invention is provided and formed in the fixture as shown in Figures 4 (c), 4 (d), 5 (b), 6 (a) and 13.
The top clamp (2) fixed to the fixture by a bolt M 12 x 60 (3) has an hemispherical groove surface as shown in Figures 4 (c) and Figure 6 (a). The resultant clamping force is applied through a special clamp (7) which has basically elliptical cam surface to press a special washer (11) through which the clamping force is transmitted, the special clamp being moved vertically and left and right hand side rotation fitted around a pin 6 x 16 (12).
The top clamp (2) is provided as an added mechanism to the fixture which not only presses round bar downwards by spring plate (8) but also enhance safety further. This top clamp is required when situation arises to enhance productivity coping up with high speed, feed and depth of cut.

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It is to be construed that without the additional top clamp (2) the fixture with special clamp (7) is sufficient to mill the entire length of round bar in one setting. In that case the top clamp is kept aside and milling operation is done alone by the special clamp provision.
The fixture is fixed in the floor table through V shaped grooves at two sides. The entire fixture has splitted block portions (1) to provide a groove and joined in a registered manner through screws M 10 (4), key (5), screws M 12 (6), and bolts (13). A stopper (10) is provided at the base of the block (1) to firmly held two plates (14) to ensure firm interconnections of the fixture and proper grip of the job and to prevent any movement of the inter connected parts of the fixture while a job is operated being held by the fixture.
The special clamp (7) has spherical end portion (S) for hand gripping and the special clamp works in pair through clamp screw (9).

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Figure 12 shows as an embodiment how two jobs (one female and another male) are milled to produce seal wire to seal the roots of gas turbine blade.
The female job (J) of 197.8 mm length taken from bottom corner to top corner of other end, shown at bottom of Figure 12 is held at 15° from the axis of groove (4), the middle portion as shown is milled with radious of curvature of R 10 + 0.2 tolerance. The grip of the job by a couple of special clamp is shown by A-A. The cross sectional view of the milled job is shown at the bottom of Figure 12 by turning the job by the clamps shown in the direction A-A. After milling the job's curvature depth is of 6.0 - 0.2 mm.
Another job (male part) of 1 88 ± 0.2 mm length is shown at the top of Figure 12. The said job is cut lengthwise to maintain a protruded portion of 6.0 - 0.2 mm depth and 14.8 ± 0.2 breadth at the middle of the job. The said two finished parts of the jobs are press fitted to constitute the seal wire at the roots of the blades.

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The reference numerals used to narrate the operation of the fixture device with reference to the drawings are scheduled as follows: -

REFERENCE NUMERALS
DESCRIPTION
QTY
1
BLOCK
1
2
CLAMP
1
3
BOLT M 12 x 60
1
4
SCREW M 10
2
5
KEY
2
6
SCREW M 12
3
7
SPECIAL CLAMP
2
8
SPRING
3
9
CLAMPIING SCREW
2
10
STOPPER
1
11
SPECIAL WASHER
2
12
PIN 0 6 x 16
2
13
BOLTS
3
14
FIXING PLATES
2
G
GROOVE
1
G1
HEMISPHERICAL GROOVE OF TOP CLAMP
1
S
SPHERICAL HAND GRIP OF THE SPECIAL CLAMP
2

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The invention as herein described and illustrated should not be construed in a restrictive manner as various modifications, embodiments and charges are possible within the scope and limit of the invention as defined in the encampured appended claims.

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WE CLAIM
1. A special fixture for manufacturing of seal wire used in fixing roots of gas turbine blades comprising:
a pair of special clamps (7) fixed in a block (1), the said clamps are operated by means of pins (12) and spring (9) to hold a job (J) in a groove (G) and are adapted to move vertically up and down and rotatable left and right hand side to grip the job in the groove axially or in inclined position and milling the job to form a groove or portrusion in it to form a seal wire for the fixing roots of gas turbine blade, the said fixture being additionally arranged with a top clamp (2) in case of high speed feed and deep cut requirement, wherein the resultant force (F) of the clamping grip of the job acts at an angle from the horizontal line, thus enhancing grip on the job through division of the acting force (F) into horizontal and downward vertical directions and thus preventing any slippage of the job.

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2. A special fixture as claimed in claim 1 wherein job is held in a spherical
groove (G) by an angular grip by the special clamps (7).
3. A special fixture as claimed in claim 1, wherein the resulting clamping
force by the special clamps (7) is transmitted through a elliptical cam
surface of the clamp when pressed on a special washer (11).
4. A special fixture as claimed in claim 1, wherein the top clamp (2) is fixed
on the top of the block body (1) by a bolt (3), and press the round bar job
downwards by means of a spring plate (8) through its hemispherical grip
(G1) and thus act to enhance further safety.
5. A special fixture as claimed in the preceeding claims wherein the groove
(G) is maintained in the fixture with splitted block portions (1) and joined
in a registered manner through screws (4 and 6), keys (5) and bolts (13).
4.
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6. A special fixture as claimed in the preceeding claims wherein a stopper
(10) is provided at the base of the block (1) to firmly held two plates (14)
to ensure firm interconnection of the fixture and to prevent any
movement of the interconnected parts of the fixture while the job is being
operated and held in the groove by the special clamps (7) or by the
special clamps (7) and top clamp (2) in combination.
7. A special fixture as claimed in the preceeding claims wherein the special
clamp (7) has spherical end portion (S) for hand gripping of it.
8. A special fixture as claimed in the preceeding claims wherein round bar
jobs are milled to produce seal wires of male and female parts, which are
press fitted to constitute a seal at the roots of the blades of gas turbine.
6.
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9. A spherical fixture as claimed in the preceeding claims wherein by
providing angular grip instead of parallel grip of round job by the special
clamps (7), the jobs are milled in single fixture setting to prevent any
slippage of a job and thus to ensure material and time saving.
10. A special fixture for manufacturing of seal wire used in fixing roots of gas
turbine blades, substantially as herein described and illustrated in the
accompanying drawings.
This invention relates to a special fixture for manufacturing of seal wire used in fixing roots of gas turbine blades comprising a pair of special clamps (7) fixed in a block (1), the said clamps are operated by means of pins (12) and spring (9) to hold a job (J) in a groove (G) and are adapted to move vertically up and down and rotatable left and right hand side to grip the job in the groove axially or in inclined position and milling the job to form a groove or portrusion in it to form a seal wire for the fixing roots of gas turbine blade, the said fixture being additionally arranged with a top clamp (2) in case of high speed feed and deep cut requirement, wherein the resultant force (F) of the clamping grip of the job acts at an angle from the horizontal line, thus enhancing grip on the job through division of the acting force (F) into horizontal and downward vertical directions and thus preventing any slippage of the job.

Documents:

01100-kol-2006-abstract.pdf

01100-kol-2006-claims.pdf

01100-kol-2006-correspondence others.pdf

01100-kol-2006-description(complete).pdf

01100-kol-2006-drawings.pdf

01100-kol-2006-form-1.pdf

01100-kol-2006-form-2.pdf

01100-kol-2006-form-3.pdf

01100-kol-2006-g.p.a.pdf

1100-KOL-2006-ABSTRACT.pdf

1100-KOL-2006-AMANDED CLAIMS 1.1.pdf

1100-KOL-2006-AMANDED CLAIMS.pdf

1100-KOL-2006-AMANDED PAGES OF SPECIFICATION.pdf

1100-KOL-2006-CANCELLED PAGES.pdf

1100-KOL-2006-CORRESPONDENCE 1.1.pdf

1100-KOL-2006-CORRESPONDENCE.1.3.pdf

1100-KOL-2006-DESCRIPTION (COMPLETE).pdf

1100-KOL-2006-DRAWINGS.pdf

1100-KOL-2006-EXAMINATION REPORT.1.3.pdf

1100-KOL-2006-FORM 18.1.3.pdf

1100-KOL-2006-FORM 2.pdf

1100-KOL-2006-FORM 3.1.3.pdf

1100-KOL-2006-FORM 3.pdf

1100-KOL-2006-FORM-27.pdf

1100-KOL-2006-GPA.1.3.pdf

1100-KOL-2006-GRANTED-ABSTRACT.pdf

1100-KOL-2006-GRANTED-CLAIMS.pdf

1100-KOL-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

1100-KOL-2006-GRANTED-DRAWINGS.pdf

1100-KOL-2006-GRANTED-FORM 1.pdf

1100-KOL-2006-GRANTED-FORM 2.pdf

1100-KOL-2006-GRANTED-LETTER PATENT.pdf

1100-KOL-2006-GRANTED-SPECIFICATION.pdf

1100-KOL-2006-REPLY TO EXAMINATION REPORT.1.3.pdf

1100-KOL-2006-REPLY TO EXAMINATION REPORT.pdf

abstract-01100-kol-2006.jpg


Patent Number 247479
Indian Patent Application Number 1100/KOL/2006
PG Journal Number 15/2011
Publication Date 15-Apr-2011
Grant Date 11-Apr-2011
Date of Filing 19-Oct-2006
Name of Patentee BHARAT HEAVY ELECTRICALS LIMITED
Applicant Address REGIONAL OPERATIONS DIVISION(ROD), PLOT NO:9/1, DJ BLOCK 3rd FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091
Inventors:
# Inventor's Name Inventor's Address
1 ANAND KUMAR SHARMA BLOCK-III,BHEL(HEEP) HARIDWAR
2 MAHENDRA KUMAR SHARMA BLOCK-III, BHEL(HEEP), HARIDWAR
3 YOGENDRA PAL SINGH RANA BLOCK-III,BHEL(HEEP),HARIDWAR
PCT International Classification Number B23Q3/06
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA