FORM 2
The Patents Act 1970 (39 of 1970)
&
The Patent Rules 2003 PROVISIONAL SPECIFICATION
(See Section 10 and rule 13) TITLE OF THE INVENTION:
HARDWARE FREE FIXING SYSTEM FOR A DRAWOUT TO FIX CONVERTIBLE TYPE BREAKER
APPLICANT:
LARSEN & TOUBRO LIMITED
L&T House, Ballard Estate, P.O. Box No. 278,
Mumbai, 400 001, Maharashtra . INDIA.
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

A) TECHNICAL FIELD
[0001] The present invention generally relates to a draw out type air circuit breaker, and more particularly to a draw out type air circuit breaker which is capable of distinguishing accurately a disconnected position, a testing position and a connected position when an air circuit breaker used in a cradle is changed from pushed in/draw out type to fixed type from a cradle
B) BACKGROUND OF THE INVENTION
[0002] Switching devices such as miniature circuit breakers, residual circuit breakers and isolators etc are used in domestic and industrial applications for protection against over currents. Air circuit breaker has been broadly classified into two types based on the type of installation as a fixed and a draw out type. A fixed type breaker is fixedly installed between an electrical power and an electrical load and a draw out type has breaker component moving in and out of a jacket enclosure called cradle so as to get separated from a power terminal and a load terminal in order to facilitate maintenance and secure stability.
[0003] Generally, an air circuit breaker is installed between a load equipment and electric power in order to protect the load equipment such as a motor and a converter, etc. and a line from an abnormal current (a short circuit, a ground fault, an over current) generated at an electric circuit such as a power transmission/distribution line and private power transforming facilities, etc. Particularly, an air circuit breaker is a breaker for extinguishing an arc generated in opening and closing of a contact within the air.
[0004] An air circuit breaker is divided into a fixed type fixedly installed between an electrical power and an electrical load and a draw out type in which a breaker is movable inside an enclosure jacket (cradle) so as to be separated from a power terminal and a load terminal in order to facilitate maintenance and secure stability.


[0005] There is a need to provide fixing system of an air circuit breaker to convert it from a draw-out type to a fixed type. There is a further need to provide the fixing system that gives the user an ease to convert the breaker from one type to another on site without using any tool or device
C) BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The other objects, features and advantages wili occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0007] Fig. 1 shows the schematic front view of fixed air circuit breaker.
[0008] Fig. 2 shows the perspective view of circuit breaker with fixe side plates.
[0009] Fig. 3 shows the perspective view of fixing, side plate.
[0010] Fig. 4 shows the perspective view of arc shield fixing plate.
[0011] Although specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
D) DETAILED DESCRIPTION OF INVENTION
[0012] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.

[0013] The various embodiments of the present invention provide a fixing system of an air circuit breaker so as to convert it from a draw-out type to a fixed type. Fixing side plates are designed such that while converting draw-out air circuit breaker into fixed air circuit breaker type, no screw or rivet fitting is required on breaker component. The fixing system comprises of two side plates and two arch shield mounting plates on each side to support the breaker and arc shield respectively. This gives the user an ease to convert the breaker from one type to another on site without using any tool or device.
[0014] A fixed air circuit breaker mainly comprises of two parts one is moulded breaker with accessories and operating mechanism (component 8 of FIG 2) and second is the arc shield (component 7 of FIG 2) which prevents the arc and ionized discharge gases from escaping directly to the enclosed environment which may affect the breaking capacity of other allied devices housed in the same chamber. Based on the type of installation, the air circuit breaker is selected either as a fixed type or a draw-out plug in type. The draw out type gives an ease of isolation and freedom of maintenance on the circuit breaker while rest of the installation (supply termination) remains intact, on the other hand a fixed type has termination fixed to breaker terminals and the breaker in turn fixed to ground. In case of any change of installation system the with-drawable breaker can be converted to fixed breaker by mounting necessary accessories.
[0015] In this case, the conversion of the breaker from a with-drawable type to fixed type can just be made by two sliding plates on each side which have no mounting requirement on breaker component. In the arc shield fixing plate (component 1 of Fig. 1) the base flange (component 14 of Fig. 4) slides inside the slot of housing on both left (component 6 of Fig. 1) and right (component 5 of Fig. I) and clamps the arc shield assembly on the top by trapping the window of the arc shield inside the C profile (component 15 of Fig. 4), and hence restricts the relative movement in all directions similarly the side plate (component 2 of Fig. 1) slides in beneath the Breaker ears on left (component 4 of Fig. 1) and right (see 3 of Fig. 1) with flanges (component 10 of Fig. 3) and supports the side walls of the breaker against the profile (component 9 of Fig. 3) , it also clamps to the front and back faces of the breaker with flanges (component 12 of Fig. 3) and additionally supports the equipment weight with the flanges (component 13 of Fig. 3) and hence restricts all degrees of freedom for the fixed breaker assembly when the side plates are fastened to ground on the cuts provided (component 11 of Fig. 3).


[0016] Novelty points: No fixing requirements on the functional component such as breaker, switch, or any such draw out type device; Easy conversion of draw out to fixed type plug in device just by adding two (set) of sliding parts; The assembly plates can be used independent of the width of functional component (which means irrespective of breaker frame and number of poles); All the fixing components (assembly plates) are single components, free from any joints like welding or hinge joints.
The detailed description and various embodiments of the invention along with the Claims shall be provided in the Complete Specification.
Dated this the 30th day of March 2009

RAKESH PRABHU Patent Agent,
ALMT Legal,
#2, Lavelle Road, Bangalore-560 001
To,
The Controller of Patents, The Patent Office, Mumbai