FIELD OF INVENTION
The present invention relates to design and development of a locating system in work
piece adaptors to hold metal blanks of different cross sections in work piece adaptor
(chuck) during machining of bar type steam turbine blades in 5 axis machines.
BACKGROUND OF THE INVENTION
The bar type steam turbine blades are manufactured in 5 axis machines from bar stocks
i.e. blanks of different cross sections. In case of two spindle machines, before loading,
the blanks of pre-defined cross sections are first cut to predefined lengths by band saw
machines and then the end faces of the blanks are machined by face milling in
horizontal milling machines. At one end face a centre drilling is done according to the
size of tailstock centre pin for aforesaid machines.
The blanks are then loaded in part changer/ job changer system. During this, as per
present practice, the blanks are loaded in a job adaptor system which holds the blank
from two corners and a pin of same size as in the tail stock comes from top and holds
the blank from top by inserting itself into the centre hole as machined previously before
loading. It then goes up, blanks are tightened from base in the adaptor by means of a
tightening arrangement, realized by rotating a bolt.
OBJECTS OF THE INVENTION
1. Therefore the object of the present invention is to design and development of a
locating system in work-piece adaptor by ensuring more holding area while the jobs of
different cross sections are held.

2. Another object of the invention is to design and development of a locating system in
work piece adopters to hold jobs of different cross-section in which the centre drilling
operation is avoided before loading in horizontal machining centre.
3. A further object of the invention is that the allowance of material in the blanks along
the length are reduced in such a way that holding remains steady and rigid with
allowance of material in length is reduced effecting saving of material consumption.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig 1 - Previous arrangement where holding of the blank by the 'blank corners'
Fig 2 - Holding arrangement of the present invention.
Fig 3 -Holding arrangement with the blank
Fig 4 - photograph view of the adopter showing part details and centering
Fig 5 - Adaptor body
Fig 6 - Rectangular jaws one number with left hand thread and one number with right
hand thread.
Fig 7 - L-shaped locator plate with marking at centre
Fig 8 - Stud with left hand and right hand thread

DETAILED DESCRIPTION OF THE INVENTION
1. At first the blanks are cut into predefined lengths by band saw machines.
2. The blanks are then machined in horizontal machining centre for face milling of the
end faces. No centre drilling has to be done.
3. The width of the blanks are known. Therefore, as shown in the assembly fig 2 and
fig 4, the bolt for locating is rotated in the L-shaped locator with marking at centre in
such a way that the end face of the bolt for locating, resides at half the distance of
blank width from the centre mark on the L shaped locator plate with marking at centre.
This is done by checking the aforesaid distance by vernier scale. The centre mark in the
L-shaped locator plate with marking at centre, is concentric with the centre of
workpiece adaptor.
4. The nut are then tightened in that position of the locating bolt.
5. The blank is then loaded in the adaptor such that one side of the blank abuts the end
face of the locating bolt.
6. The stud is tightened by means of alien keys to tighten the rectangular jaws from
both sides to hold the blank. Here jaw with right hand thread shall be fastened in the
side of stud with right hand thread and similarly left hand threaded jaw shall be
fastened in the side of stud with right hand thread.
7. The adaptor along with the blank then goes into the machine for machining.
8. Centre drilling in the face of blank towards the tail stock of the machine is then gone
through a centre drilling operation in machine before holding finally by tail stock pin.
9. The machining starts after this.

WE CLAIM
1. A locating system in work piece adaptors to hold metal blanks of different cross
sections comprising:
a L-shaped locator body (3) with nuts (5) and bolt (4) mounted on a work piece
adaptor (1) with jaws (2)
characterized in that the bolt (4) is fixed in the locator body (3) in a position such that
the inner face of the bolt (4) is at half the distance (D) of the width 2D of the blank (6)
from the centre line (C) of the locator body (3) and tightened by the plurality of nuts in
the position wherein the face of the bolt abuts one face of the blank for centering of the
work piece.
2. The locating system as claimed in claim 1 wherein the blank is hold in the adaptor
chuck (1) by a pair of rectangular jaws (2) having a left hand and a right hand screw
threads respectively.
3. The locating system as claimed in claim 1 wherein the half distance (D) of the blank
width (2D) from the centre line (C) of the locator body (3) for pre-location of the bolt
face is measured by a vernier scale.
4. The locating system as claimed in claim 1 wherein the rectangular jaws are
tightened by a stud having a right hand and a left hand threads on the two sides.

ABSTRACT

A locating system in work piece adaptors to hold metal blanks of different cross
sections comprising:
a L-shaped locator body (3) with nuts (5) and bolt (4) mounted on a work piece
adaptor (1) with jaws (2)
characterized in that the bolt (4) is fixed in the locator body (3) in a position such that
the inner face of the bolt (4) is at half the distance (D) of the width 2D of the blank (6)
from the centre line (C) of the locator body (3) and tightened by the plurality of nuts in
the position wherein the face of the bolt abuts one face of the blank for centering of the
work piece.