FIELD OF INVENTION
The present invention relates to the Working Platform adjustable at various heights during Stator Core assembly of Turbo Generators which also involves, pressing & welding. Particularly this invention is related to providing a Safe & steady platform, to perform assembly operations involved in core built up in vertical condition; which takes place in a core pit. This platform can be adjusted & clamped up to the height of six meters with stability, as per requirement to lift weight of machine equipment, man and material.
BACKGROUND OF THE INVENTION
Turbo Generators mainly consists of two parts. One is Stator (Static part) & other is Rotor (Rotating/dynamic part).Turbo Generator Stator has main component known as CORE, which is made of 0.5mm thickness stamping (insulated laminated steel sheets). This Core is manufactured separately outside the stator frame (in case of 250MW, 600MW, 660MW,700MW& 800MW). As the core is manufactured in vertical condition in Core pit, various operations mainly Intermediate pressing (cold/hot pressing), Final pressing, Core bar welding, Compression ring& Spring basket welding; at different heights. So there is

requirement of such platform which is steady & safe for working and can be adjusted at any height as per requirement.
After Stator Core assembly, other activities like Insertion of core into the stator frame takes place in Core pit so the working platform should be in nature which can be dismantled after use.
Since the stator assembly takes place in Core pit; the motorized platform is not feasible due to the space constraint. Due to this space constraint a need was felt for developing a special Working Platform, that can be easily assembled & dismantled as per requirement during Core Assembly.
The stator core assembly is carried out inside the Core pit in vertical direction. Core Pit is a PIT 4.5 meter wide and 6 meter deep from the ground level. Core assembly is carried out by standing inside the bore of core for this purpose one telescopic hydraulic lift is already installed in the pit. There are so many activities which are to be performed around the core for which a working platform is required along with the inner telescopic platform. The scheme for core assembly is shown in the figure-1a of Sheet 1. This consists of 8-bottom supports, Base plate, round support and T&A Plate. Base plate is a plate 250mm thick, 6 meter long and 4.2 meter wide. This plate is paced over the bottom support approx

1.85 meter from the base of pit. There is very small gap left between the plate and wall of core pit (around 150 mm each side). Due to the space constraint it is not possible to install the motorized working platform as available for the other manufacturing area where core is manufactured outside the core pit. But without outer platform core building was not possible. Temporary platform were manufactured but they were not safe. Due to the space constraint it was decided to use the base plate as the base of the platform to be manufactured. The platform should be able to hold its position at various heights; it should travel from the base of core to the top most position of core (Approx 8 meter). For the working at higher levels the platform should be safe & steady in nature and user friendly also. Vertical movements of platform are to be done using over head cranes.
OBJECTS OF THE INVENTION
To provide a special type of working platform around the core at the time of core assembly inside the core pit by resolving the problem of space constraint between base plate and wall of core pit.

An object of the present invention is to provide a Working Platform for Stator
Core assembly which is adjustable at various heights as per
requirement/operations.
Another object is to provide such facility which can be easily assembled & dismantled before &after the Stator Core assembly in Core pit.
Yet another object is to provide safe & steady working condition during Core assembly at various heights which can withstand the weight of man, material & machinery.
A further object is to provide a Working platform that can be used for all types of Turbo Generator Stator Core Assembly, in which the Stator core is manufactured outside the Stator frame & in vertical condition.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The present invention related to the Working Platform to be used for Stator Core
assembly, which comprises of:-a) Side Clamps (1) b) Guide Pipes(2)

c) Platform (3)
d) Locking Bolts(4)
e) Special Screws (5)
f) Locking Nuts(6)
g) Split Pins (7)
The platform should be such that it can accommodate the core inside in vertical condition, it can travel and hold its position at various heights also it should be steady and safe.
For up down movement of platform 4 pipes are provided at 4 corners. These pipes are assembled with special Side-Clamp. This Side clamp is assembled on base plate and it is designed / invented such that it can accommodate the space between pit wall and base plate. Also this clamp should be able to hold the pipe in vertical condition on which the platform can be moved up and down and can be locked at desired height. For holding the platform at desired height, various holes are made in the pipe. A matching pipe of larger diameter having single hole is assembled to the top of working platform. Guide pipe passes through the pipe assembled on platform. Single hole on pipe assembled on platform is matched with the holes provided on guide pipes and the position of platform is locked at desired height by inserting a locking bolt at all the four corners.

Fig.(1a) (see sheet no-1)shows the complete assembly of Working platform that is invented; used for Stator Core assembly.
Fig.(1b) (see sheet no-2), shows the plan view of the complete assembly of Working Platform which shows assembly of Locking bolt (4) with the Platform (3) using locking nut (6) & split pin (7).
Fig.2 (see sheet no-3), shows the Side clamp, this item is to be clamped with Assembly plate on which whole Core assembly takes place.
Fig.3 (see sheet no-4), shows the Guide Pipe, on which Working Platform guides & locked at the required height. This Guide pipe is having various holes, on which the platform is being locked at desired height.
Fig.4 (see sheet no-5), shows the Platform, which is a structure made of welding by grating plate, angles & plates.
Fig.5 (see sheet no-6), shows the Locking bolt that is used for locking of Platform with Guide pipe at desired height.
So this invention is basically related to a Working Platform to work the different heights as per requirement, during Stator Core assembly of Turbo Generator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
Accordingly, there is provided a Working Platform, adjustable at different height for TG core built up, which comprises of:-

Fig. (1a) & (1b) (see sheet no.1& 2) shows the Complete Working Platform, assembled in working condition for Stator core assembly according to present invention. The whole method of clamping/ working of Working platform at different heights is as follows:-1. Fig.2 (see sheet no-3), shows the Side clamp.

Firstly the four Side clamps (1) are to be clamped at Assembly Plate at four corners. The height (H) of Side clamp (1),is selected according to the thickness of Assembly plate. Diameter (ØD1) is according to the step diameter (øD2) of Guide Pipe (2). The side clamps(1) are to be clamped to suit the hole positioning dimensions (A & B), of the Platform (3) with the help of Special screws (5).
2. Fig.4 (see sheet no-5), shows the Platform
After clamping of the Side clamps (1), Platform (3) is to be kept on the top of the side clamps(1) so that that Dimension (A & B) suits to the gap of all four Side Clamps (1).Hole diameter (ØD1) of Side clamps(1) & Hole diameter (ØD5) of Platform (3) becomes concentric.
3. Fig.3 (see sheet no-4), shows the Guide Pipe
After placing of Platform (3), Guide Pipe (2) is to be inserted vertically into Platform (3) that fits to inner diameter of Side clamp (1). Guide pipe (2) 's step dimension (X)& Diameter (ØD2) goes inside the Side camp(1) and stops when it reaches to the diameter (ØD3). All four Guide Pipes(2) are to be inserted in similar manner, so that Guide pipes(2) are now vertically clamped& locked with Side clamps(1).Theses Guide pipes (2) are also

clamped by the Special screws (5) into the holes available at face of Side clamps(1).
4. Now the Platform (3) is to be vertically lifted using crane. Outer diameter (ØD3) of Guide Pipe (2) is according to the inner diameter (ØD5) of the Platform(3).The Platform (3) can move upward & downwards through Guide pipe (2).
5. Fig.5(see sheet no-6), shows the Locking
The Locking bolt (4) is to be used for locking of Platform (3) at desired height as per the requirement. Size (ØD6) of Locking bolts (4) is selected according to the hole size (ØD4) in Platform(3) & Guide pipe(2). Locking Bolts(4) are also locked by Locking nuts(6) & then again restricted by Split Pin (7) to ensure the safe locking of the platform.
6. The provision of locking is manually by the person, already present into the
Platform (3). Inner Diameter (ØD) of Platform(3) is according to Outer
diameter (ØD') of Turbo Generator stator Core (maximum outer diameter i.e.
outer diameter of Spring Basket).

WE CLAIM
1) A working platform (3) for stator core assembly of turbo generator
comprising,

2) The working platform as claimed in the preceding claim, wherein, side clamps (1), clamped at four corners with the assembly plate, to suit the hole positioning dimensions (A & B), of the platform (3), with the help of allen screws (5).
3) The working platform as claimed in the preceding claims, wherein, guide pipes (2) to guide the movement of the platform upward and downward, having plurality of holes for fixing the platform at variable heights.

4) The working platform as claimed in the preceding claims, wherein, locking bolts (4), locking nuts (6), split pins(7) to lock the platform at desired height with the holes in the guide pipes and restrict any movement thereon.
5) A method of assembly of a working platform (3), used for turbo generator stator assembly, wherein, the assembly plate is clamped by side clamps (1) on four corners, accommodating the stator core inside in vertical condition; Placing the platform at the top of the clamps, to suit the dimensions (A & B), while hole diameter D1 of side clamps (1) and hole diameter D5 of platform (3) are concentric;
Insertion of guide pipes (2) vertically in to platform(3), to be clamped & locked with side clamps(l) facilitating upward and downward movement of the platform; Locking of platform at desired height by locking nuts and locking bolts.