FIELD OF THE INVENTION

[01] The present invention relates to a common root locator used in turbine blade, more particularly the common root locator, placed in a turbine blade used for milling both the top and bottom surfaces of the turbine blade, so that said locator can be used universally.
BACKGROUND OF THE INVENTION
[02] Background description includes information that may be useful in understanding the present subject matter. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed subject matter, or that any publication specifically or implicitly referenced is prior art.
[03] Steam turbine blades are manufactured in CNC 5 axis milling machines by using milling rectangular flat bars. The metal bar stocks are blank of different rectangular cross sections and lengths. This metal bar is milled before it can be used as turbine blade. The top and bottom surface of the blades have certain radius as per configuration of rotor and stator of the turbine. These ends of the turbine blades are milled by using horizontal milling machine. The dimension of the blade root slots are varied largely. Moreover, during root and shroud milling in horizontal milling machine, the blade is axially located and constrained in ‘X’ direction with the use of root locator placed into the root slot of the blade and restricts motion in direction of axis of the blade and transverse direction of blade axis.
[04] In the prior art, the root locator according to the various slot sizes were manufactured individually and placed with root locator with the help of fasteners. This needs a large inventory of root locator as slot size of blades vary vastly. For example, the slot size of blades may vary from as 15 mm to 50 mm varying with every 0.1 mm etc. The large inventory causes a huge manufacturing cost with other problem as discussed later.
[05] Further, in the conventional art, the root locator and slot lock pieces form an assembly which is placed into the root slot and restricts axial movement of blade. The slot lock piece is having dimension ‘D’, and the required dimension is varies for each different blades. So there is huge manufacturing cost. The other problems are as mentioned below:
[a] high setting time for each stage of blades,
[b] dependency on individual slot lock pieces,
[c] hold up due to possible unavailability of slot lock pieces, and

[d] manufacturing cost of individual root locator is very high.
Hence, there is a need of common root locator to address the above mention problem.
OBJECTS OF THE INVENTION:
[06] The object of the present invention is to overcome the above mentioned drawbacks in the
prior art.
[07] The main object of the present invention is to standardize a universal type root locator to
be placed into the slot of the turbine blade with wide range of the slot dimension.
[08] Another object of the present invention is to provide a common root locator which can be fixed in the slot of turbine blade irrespective of various dimension of the blade root slots.
[09] Still another object of the present invention is to reduce the high setting time of each stage of blades.
[010] Yet another object of the present invention is to provide the blade axis remains horizontal to both the surfaces “A” and “B” of the reference system.
[011] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION:
[012] One or more drawbacks of conventional root locator, for placing root locator in the slot space of the individual turbine blade for milling purpose, are overcome, and additional advantages are provided through the system in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
[013] The present invention is directed to a common root locator, placed in a turbine blade of milling purpose. The common root locator placed in a turbine blade keeping its axis parallel to both surfaces “A” and “B” horizontally, the common root locator comprising : at least one fixed root locator carrier , at least one movable half slot lock piece and at least three grub screws for

adjusting the distance (D) between the movable half slot lock piece and fixed root locator, for fixing the common root locator inside the slot space of the turbine blade; wherein the common root locator placed inside the slot space of the turbine blade located in a reference system for milling both top and bottom surface of the turbine blade.
[014] In the embodiment, the root locator placed in the slot space of the turbine blade is fixed in a reference system for milling both top and bottom surfaces of the blade.
[015] In the embodiment, the assembly is arranged in such a manner that the root locator can be fixed inside the slot of the turbine blade by varying the distance by adjusting the required component fixed in the root locator.
[016] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
[017] it is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
[018] the foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
[019] the illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of apparatus that are consistent with the subject matter as claimed herein, wherein:
[020] Fig 1a: illustrates the root locator (100) having a movable half slot lock (101) and a fixed root locator carries (102) and at least three grub screws (G1, G2 and G3) for adjusting the dimension of the root locator which is placed in the slot space of the turbine blade (300).

[021] Fig 1b: illustrates the root locator (100) having both the ends as the fixed root locator (102) and movable half slot lock (101) along with the three grub screws (G1, G2, G3) for adjusting the distance “D” between both the part of the common root locator (100).
[022] Fig 1c: illustrates the first part of the root locator (101) which is flexible or movable for adjusting the distance “D” between both the root locators by using the screws (G1, G2, and G3). [023] Fig 1d: illustrates the second part of the root locator (100) which is fixed root locator (102) for holding the screws (G1, G2 and G3) used for adjusting the distance between both parts of the root locator (102).
[024] Fig 2a: illustrates an isometric view of the common root locator (100) placed in the slot of the turbine blade with variable slot dimensions.
[025] Fig 2b: illustrates another isometric of view of the common root locator (100) placed in the slot of turbine blade (300).
[026] Fig 3: illustrates the turbine blade (300) with mentioning the slot dimension through an arrow as indicated in the drawings.
[027] Fig 4: illustrates the reference system (Hydraulic fixture fitted in the horizontal milling machine) (400) in which the work-piece i.e. turbine blade (300) is clamped with root and shroud portion. Moreover root of the turbine blade is clamped with angle block (407) , changeable pad at root at bottom (408), the root locator (100), top thrust piece (409) and front thrust piece clamp (406) and further the shroud side of the turbine blade is clamped with angle block (405) and changeable pad (404); shroud locator (401) at back side of turbine blade; top thrust piece (402) and front thrust piece (403).
[028] Fig 5: illustrates the side view of the reference system for clamping the blade. Moreover, the turbine blade axis is placed in the reference system (400), keeping its axis parallel in both the surfaces “A” and “B” horizontally.
[029] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION:
[030] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[031] The drawings illustrate only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be clear to those of ordinary skill in the art having benefit of the description herein.
[032] In the present invention, as shown in the fig-1a, 1b, 1c, 1d, the different views of common root locator and its parts are illustrated here. The common root locator consists of the following parts: a) movable half slot lock piece (101) as shown in fig. 1c, b) fixed root locator carrier (102) as shown in the fig.1d and
c) required at least three grub screws (G1, G2, G3) for adjusting the distance between both movable and fixed root locator as shown in fig. 1a and 1b.
[033] Moreover, during root and shroud milling in horizontal milling machine, the blade is axially located and constrained in ‘X’ direction with the use of slot lock piece or placed into the root slot of the blade and restricts motion in re-direction of the blade as shown in fig. 5. The demonstration of the blade root slots vary largely, wherein the blade is placed in the support structure as mentioned fixture fitted in the milling machine as shown in fig. 4. In the present invention, individual slot lock pieces are not required to be changed for each new slot sites of blades. Rather one single assembly setup of fixed root locator carrier as per shown in fig. 1a and 1b and ensures adjustable distance ‘D’ as shown in the fig. 1a and 1b, by rotating the screws shown in fig 1b. The grub screws G1 and G3, which are fixed in the flexible slot lock piece (101), are rotating in clockwise direction and grub screw G2 which is fixed with fixed part (102) of the root locator, is rotating anti-clockwise direction.
[034] Further, while the support structure is fixed in the horizontal milling machine, as shown in the fig-4 and fig 5. Both the faces end as mentioned top and bottom face, as shown in the fig-4

are milled for the particular radius as per configuration in horizontal milling machine. The main criteria for holding the turbine blades in the fixture fitted in the reference system, is ensuring that,
1. both the top and bottom surfaces of the turbine blade are easily accessible by the tool for milling purpose;
2. turbine blade is clamped hydraulically in the reference system;
3. turbine blade centre axis is aligned in such a way that the blade axis remains horizontal to both the planes ‘A’ and ‘B’ as shown in fig-5;
4. root side of the blade is clamped angled block (407) , changeable pad at root at bottom (408), the root locator (100), top thrust piece (409) and front thrust piece clamp (406) and,
5. The shroud side of the turbine blade is clamped with angle block (405) and changeable pad (404); shroud locator (401) at back side of turbine blade; top thrust piece (402) and front thrust piece (403) as shown in fig-4 and fig-5.
[035] In the present invention, the reference system (400) is as disclosed as clamping reference of a horizontal milling machine for milling both the ends of the turbine blade as shown in fig 4 and fig 5. The distance ‘D’ varies with rotation and fixing of screws and shown in fig.1a and fig.1b. In the present invention, the slot space dimension of turbine blade (300) have been in the range of 15 mm to 50 mm and similarly the dimension “D” in between movable half slot lock piece (101) and fixed root locator (102) of common root locator (100) have been in the range of 15 mm to 50 mm. This ensures the universal working environment of the present invention.
[36] The advantages of the present invention are mentioned as below:
Advantages:
1. The problem of high setting time for each stage of blades is reduced.
2. The dependency on individual slot lock pieces is eradicated.
3. There is no hold up due to possible unavailability of slot lock pieces.

We Claim,
1. A common root locator (100) placed in a turbine blade (300), keeping the axis of
turbine blade parallel to both surfaces “A” and “B” horizontally, fixed in the reference
system, the common root locator comprising :
- at least one movable half slot lock piece (101), at least one fixed root locator carrier (102), and at least three grub screws (G1, G2,G3) for adjusting the distance (‘D’) between the movable half slot lock piece (101) and fixed root locator (102), of the common root locator (100) for fixing said locator inside the slot space of the turbine blade (300); wherein
- the common root locator placed inside the slot space of the turbine blade (300) located in a reference system (400) for milling both top and bottom surface of the turbine blade.

2. The common root locator fixed in the reference system (400) as claimed in claim 1, wherein the reference system (400) incorporates the root of the turbine blade and shroud side of the turbine blade for milling purpose.
3. The common root locator (100) placed in a blade (300) as claimed in claim 1, wherein the dimension “D” in between movable half slot lock piece (101) and fixed root locator (102) of common root locator (100) can be in the range of 15 mm to 50 mm.

4. The common root locator placed in a turbine blade as claimed in claim 1, wherein the
root locator placed in the turbine blade having in the reference system (400), wherein
the root of the turbine blade is clamped with angled block (407) , changeable pad at
root at bottom (408), the root locator (100), top thrust piece (409) and front thrust
piece clamp (406) and wherein,
the shroud side of the turbine blade is clamped with angle block (405) and changeable pad (404); shroud locator (401) at back side of turbine blade; top thrust (402) and front thrust (403).
5. The common root locator placed in a turbine blade as claimed in claim 1, wherein the
root locator (100) having the three grub screws (G1, G2, G3) using for adjusting the
slot space of the root locator by rotating the screws in its unique directions.