FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
PROVISIONAL / COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION:
”A Novel Device for Heat Treatment of Large-size Equipments"
2. APPLICANT:
(a) NAME : Larsen & Toubro Limited.
(b) NATIONALITY : An Indian Company registered under the
provisions of the Companies Act, 1956
(c) ADDRESS : Larsen & Toubro Limited,
L&T House, Ballard Estate, Mumbai- 400001 Maharashtra State, India

3. PREAMBLE TO THE DESCRIPTION:
PROVISIONAL
The following specification describes the invention.

The following specification particularly describes the invention and the manner in which it is to be performed.



Title
A Novel Device for Heat Treatment of Large-size Equipments.
Technical Field
The present invention relates to a device for heat treatment of large-size equipments. More particularly, the present invention relates to a novel device to carry out the heat treatment of large-size equipments in a vertical position and with minimal handling.
Background and Prior Art
In the Aerospace Industry, the fabricated equipments like motor casings needs to be heat-treated to get the required strength of the material by hardening. Manufacturers dealing with such large-size equipments prefer to or rather force to carry out the heat treatment in a vertical position so that the effect of gravity does not affect the shape. For that they typically use either a pit-type furnace or a bell-type furnace.
A pit-type furnace has to be placed in a pit that has to have a huge concrete wall build-up on all sides, so as to withstand the anticipated push from ground-water forces and also to keep the furnace waterproof. The construction therefore necessitates substantial monetary investment.
A bell-type furnace is comparatively less costly. However since the bell of the furnace has to be lifted at least up to two times the height of the job undergoing heat-treatment, i.e. typically as high as 25 to 30


meters, it calls for special-purpose material handling equipment like cranes.
As such therefore, in the above-mentioned context, the fabricators have to either invest huge amounts of money in constructing pit-furnaces or otherwise have to organize logistics and also tackle the risk of lifting large-size structures to very high levels with suitable material handling equipment like cranes.
Drawbacks of Prior Art
1. The furnaces that are used to carry out heat treatment of large-size jobs in vertical position either require very large monetary investment or require special-purpose material handling equipment in high-roof shops.
2. The above drawbacks are compounded by the challenges the prior art furnaces pose with respect to huge construction activities involved, or difficulty and safety risks associated with handling of large-sized equipments that are to undergo the heat treatment.
Objects of the Present Invention
The object of the present invention is to have a suitable device to avoid large monetary investment.
It is a further object of the invention to eliminate requirement of any special-purpose material handling equipment like high-lift cranes in a high-roof shop etc and the associated safety risks.


Description of the Figures of the Present Invention:
Figure 1 shows the front view of the device for heat treatment of the
large-equipments.
Figure 2 shows top view of the device for the heat treatment.
Description of the Present Invention
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the preferred embodiment.
In accordance with the present invention, a furnace is constructed above the ground in such a manner that the job undergoing heat-treatment is vertically positioned on a fixed hearth, and the body and the roof of the furnace splits vertically and like a trolley moves along specified rails thus without requiring any high lifting of the job. The furnace which is split into two halves is closed around the job again using movement along specified rails from two sides of the job; and interlocked and secured in desired position before heat-treatment commences. As such therefore neither does it require any construction of pit etc nor any special-purpose material handling and lifting facilities or a high-roof shop.


Device and method of the Present invention
The device and method of this invention in its preferred embodiment has a construction as depicted in Fig 1 and is explained below.
The furnace consists of two halves (1) and (2) that are provided with suitable wheels (3) attached underneath that can move along the rails (4). The hearth (5) is stationary on the floor (6). The job (7) undergoing heat treatment is placed on the hearth (5) in a vertical position and is secured to the hearth (5) with the help of suitable fixing arrangement (8). The hearth with the job is then positioned firm on the ground. The two furnace halves (1) and (2) are then moved along the rails to close around the hearth and the above-said job; and are interlocked with the help of suitable locking arrangement (9) provided on the halves. The heat treatment is then carried out.


Advantages of the Present Invention
1. No need to make large investments of money in constructing pit-type furnaces for the purpose of heat-treating a flimsy but large-sized job in a vertical position.
2. No any special-purpose material handling equipment is required which is difficult to organize and also have greater safety risks associated with it.
3. No need to have a high-roof shop to house a tall furnace with sufficient space above it for lifting and placing a large-sized job inside the furnace.