FIELD OF INVENTION
The present invention relates to a universal adjustable device for root and shroud milling of steam turbine blades on CNC horizontal machining center. More particularly it relates to a rigid and uniform clamping device for steam turbine blades of all sizes and rhomboid angles while root and shroud machining on CNe horizontal machining center takes place, so that the blade center axis remains completely horizontal.
BACKGROUNP OF INVENTION
Steam turbine blade is a very precise and critical component of Steam turbine system. At present root and shroud milling is carried out by using fixed pads at root and shroud to clamp the blade horizontally.

In this system, different fixed pads are required for each type of blade. Each fixed pad is of a standard height and has to be changed for different blades and this leads to a large inventory, longer cycle time for procuring/manufactuiing of these pads and increased setting time, which results in decrease in productivity. Also maintaining and repairing of such a large number of pads is difficult.
As there is a wide range of blades being manufactured, the frequent changing of pads is cumbersome, time consuming and increases the possibility of error during setting.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a universal adjustable device for root and shroud milling of steam turbine blades on CNC horizontal machining center which eliminates the disadvantages of the fixed Pad system of Prior art.

Another object of the invention is to propose a universal adjustable device for root and shroud milling of steam turbine blades on CNC horizontal machining center, which is able to reduce the inventory of pads required for root and should milling of steam turbine blades.
An yet another object of the invention is to propose a universal adjustable device for root and shroud milling of steam turbine blades on CNC horizontal machining center which is capable of shortening the setting time required for root and should milling of steam turbine blades.
A further object of this invention is to propose a universal adjustable device for root and shroud milling of steam turbine blades on CNC horizontal machining center, which results in improving the productivity of Root and shroud milling of steam turbine blades.

SUMMARY OF INVENTION
Accordingly, there is provided a universal adjustable device for Root and shroud milling of Steam turbine blades on CNC horizontal machining center comprising mainly of:·
a) Base (1)
b) Blade Rest (2)
c) Wedge (3)
d) Bolt (4)
e) Nut (5)
f) Cover Plate (6)
g) Screws - 2 No. (7)
The blade root or shroud is positioned on top of the Blade Rest (2). The Blade Rest (2) can slide only in vertical direction along the slots machined in the Base (1) and it rests on the Wedge (3). The Wedge (3) can move in horizontal

direction in the recess machined in the Base (1). The Blade Rest (2) lies on top of the Wedge (3). The Bolt (4) passes through the Base (1) and the Wedge (3).
For root and shroud milling of a bladel the axis of the blade should lie horizontally. This is controlled by the height of the pads on which the root and shroud rests.
Rotating the Bolt (4) causes the Wedge (3) to move in the horizontal direction. This in turn adjusts the height of the adjustable pad as required. Different rhomboid angles can be accommodated by using a set of Blade Rests (2), one for each angle, which usually five in numbers.
Nut (5) is used to lock the translation of the bolt with respect to the base.
A Cover Plate (6) is then fixed with the help of Screws (7) from the side to completely guard the mechanism from chips and coolant.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Fig.l(a)- Shows three dimensional (3D) isometric view of the universal adjustable device for root and shroud milling of steam turbine blades on CNC horizontal machining center according to present invention.
Fig.l(b) - Shows the 3D isometric view with the cover removed.
Fig.2 - Shows the cross sectional view of the universal adjustable device
according to present invention.
Fig.3 - Shows the universal adjustable device with disassembled parts
according to the invention.
Fig.4(a) - Shows the sketch of a base with slots for guiding the blade rest according to the invention.

Fig.4(b) - Shows an isometric view of the base according to the invention.
Fig.5(a) - Shows the blade rest with keys according to the invention.
Fig.5(b) - Shows an isometric view of blade rest with keys according to the invention.
Fig.6(a) - Shows the sketch of a wedge having a taper surface according to the invention.
Fig.6(b) - Shows an isometric view of the wedge according to the invention.
Fig.7(a) and (b) - Shows the sketch and 3D view of the bolt threaded to the wedge according to the invention.
Fig.8(l) and (b) - Shows the sketch and 3D view of the nut engaged with the bolt according to the invention.

Fig.9(1) and 9(b) - Shows the sketch and 3D view of the cover according to the invention.
Fig.10(a) and 10(b) - Shows the sketch and 3D view of the screw to fix the cover according to the invention.
Fig.ll - Shows the 3D view of the base with standard Pad according to prior art
Fig.12 - Shows the 3D view of a steam turbine blade mounted on the universal adjustable device during root and should milling according to invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Fig.1, Fig. 2 and Fig. 3 (see sheet no.1, 2 and 3) show the universal adjustable device which comprises of a Base (1), a Blade Rest (2), a Wedge (3), a Bolt (4) and Nut (5) along with two Screws (7) and a Cover (6).
Fig.2 shows the universal adjustable device displaying the inner configuration of the wedge (3), Blade rest (2), the bolt (4) and Base (1),
The Blade Rest (2) is guided in the Base (1) with the help of slot e8} and key (l2) mechanism. It rests on the Wedge (3) which in turn lies in the recess (9) of the Base (1).
Fig.4 (a) and Flg.4 (b) shows the Base (1) which has slots (8) to guide tiie Blade Rest (2). There is also present a recess (9) for the Wedge (3) to be placed and a

hole (10) for the Bolt (4) to pass through. Two threaded holes (11) are provided on the side to screw on the Cover (6).
The blade rest has keys (12) on both sides which fit in the slots (8) in the Base (1). The lower portion has a taper surface (13) cut to meet the Wedge (3) at the required angle.
The wedge has a threaded hole (14) to fit the Bolt (4) and a taper surface (15) where the Blade Rest (2) mates with it.
The surfaces of the Blade Rest (2) and the Wedge in contact are at an angle with the horizontal. This allows the height of the Blade Rest (2) to be adjusted by horizontal movement of the Wedge (3).
To accommodate for a change in angle of the blade, the upper surface of the Blade Rest (2) has to be machined in a taper corresponding to the angle. Thus we will have a set of interchangeable Blade Rests (2), one for each angle being machined, which are usually five in number.

The Wedge has a threaded hole in which the Bolt (4) is fitted. Thus by rotating the Bolt (4), it is possible to move the Wedge (3) horizontally.
The Bolt (4) is fitted through the hole in the Base (1) and a Nut (5) is screwed on the Bolt (4) before fitting the Wedge (3). This is then welded to the Bolt (4) so as to lock and prevent any relative motion between the two. This locking prevents the translation of the Bolt (1) and only allows it to rotate in its position.
The Cover (6) is screwed on to the Base (l) with the help of Screws (7). This is done to protect the inner mechanism.
After assembly, it is possible to adjust the height of the pad by turning the Bolt (1) to move the Wedge (3) which adjusts the Blade Rest (2).

WE CLAIM
1. A universal adjustable device for root and shroud milling of steam turbine blades on CNC horizontal machining center comprising;
- at least one base (1);
- at least one blade rest (2);
- at least one wedge (3) having a taper surface (13);
- at least one bolt (4) fitted to the wedge;
- at least one nut (5);
- at least one cover plate (6);
- a plurality of screws (7); Characterized in that,
the blade rest (2) having keys (12) on both side is guided in the slot (8) of the base (1) and rests on the wedge (3) for creating a surface of blade rest (2) at an angle with the horizontal for a tapered machining corresponding to the angle of the turbine blade wherein the bolt (4) is welded to a nut (5) and fitted to the threaded hole of the wedge (3) for

moving the wedge horizontally for adjustment of the height of the blade rest (2).
2. A universal adjustable device as claimed in claim 1, wherein the wedge lies in the recess (9) of the base (1).
3. A universal adjustable device as claimed in claim 1, wherein the lower portion of blade rest (2) has a taper surface (13) for meeting the wedge (3) at the required angle.
4. A universal adjustable device as claimed in claim 1, wherein the cover plate (6) is fitted to the base by the screws (7).
5. A universal adjustable device as claimed in claim 1, wherein a hole (10) is disposed on the wedge (3) for accommodating the bolt (4).

ABSTRACT

A universal adjustable device for root and shroud milling of steam turbine blades on CNC horizontal machining center comprising at least one base (1); at least one blade rest (2); at least one wedge (3) having a taper surface (13); at least one bolt (4) fitted to the wedge; at least one nut (5); at least one cover plate (6); a plurality of screws (7); The blade rest (2) having keys (12) on both side is guided in the slot (8) of the base (1) and rests on the wedge (3) for creating a surface of blade rest (2) at an angle with the horizontal for a tapered machining corresponding to the angle of the turbine blade wherein the bolt (4) is welded to a nut (5) and fitted to the threaded hole of the wedge (3) for moving the wedge horizontally for adjustment of the height of the blade rest (2).