FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See Section 10; rule 13)


TITLE OF THE INVENTION Brake Lining Dust Removal System
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Mr. Pradeep Bhilare,
An Indian National of
TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Ho mi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India

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


FIELD OF INVENTION
This invention relates to the brake system of an automobile and more particularly it relates to system for removing dust from brake lining.
BACKGROUND OF INVENTION
All automobiles are provided with brake system to reduce risk of any mishap. Air brake system is one of the commonly used brake systems in Medium and Heavy commercial vehicles (HCV), Utility vehicles (UV) and Light Commercial Vehicle (LCV)s. Air brake circuit mainly consist of a brake pedal, Dual Foot valve, compressor, air tank, multi-circuit protection valve, condensate oil separator, air drier, hoses, brake chamber, automatic slack adjuster and drum brakes. The driver pushes the foot valve treadle down and air pressure flows to the front and rear brake chambers. The brake chamber push rod moves the slack adjusters to rotates the S-cams forcing the brake shoes against the drums. This causes friction that stops the wheels. The driver releases the foot valve treadle and the air in the brake chamber is allowed to exhausted to atmosphere, releasing the brakes. During the braking operation foundation brakes may make irritating noise. Some of the reasons for brake noise are listed below.
1) Brake assembly having uneven strap profile and riveting process which creates more gaps between lining and shoe strap.
2) Brake shoe angle change.
3) Drum run out.
4) Brake lining material dust inside the drum.
5) Metal particles in the linings.
6) Hardness of drum and lining.
7) Shoe hold down spring.
8) Environment condition.

During braking the shoe touches the drum and because of friction the lining rubs the drum and small amount of dust is formed in every brake. As stated above presence of brake lining material dust also creates noise by affecting contact pattern of the lining and drum. By removing the dust from the drum brake, noise can be reduced.
OBJECTS OF INVENTION
> The main object of this invention is to remove brake lining material dust from brake assemblies.
> To improve brake performance as well up to some extent, without adding any special features in the brake system.
STATEMENT OF INVENTION
This invention relates to a brake lining dust removal kit system comprising: a first ducting arrangement connecting exhaust side of an air brake valve for front brakes to air nozzles provided proximal to front brakes; a second ducting arrangement connecting exhaust side of an air brake valve for rear brakes to air nozzles provided proximal to rear brakes; said air nozzle having at least one outlet fixed on a brake assembly dust shield provided on each of said front and rear brakes to blow exhausted air in the gap between brake lining and brake drum.
BRIEF DESCRIPTION OF INVENTION
A system is developed to remove brake lining dust collected on brake drum and brake lining by blowing exhaust air of brake system. For front brakes exhaust of primary circuit used which is exhausted through foot brake valve and for rear brakes exhaust through quick release valve or relay valve of the secondary circuit depending on the design. Required ducting is proposed to carry air from foot brake valve, relay valve or quick release valve to foundation brakes.

BRIEF DESCRIPTION OF DRAWINGS
Fig.l shows general arrangement of brake circuit in accordance with the invention. Fig 2. Shows the nozzle arrangement for applying air to remove dust Fig 3 shows the arrangement of nozzle with brake assembly
DETAILED DESCRIPTION OF INVENTION
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same,
The proposed brake lining dust removal arrangement consists of normal brake circuit in which compressor (1) drying and distribution unit (2) front air tank (3) rear air tank (4) dual treadle valve (5) load sensing valve (6) relay valve (7) hand brake valve(8) quick release valve (9) rear spring brake actuator RH & LH (10 & 11) front brake chamber RH & LH (12 & 13) wheels with foundation brakes inside it (14) and ducting arrangement for front brakes (15) & rear brakes (16) and air nozzle (17).
The ducting arrangement for front brakes (15) & rear brakes (16) can be made up of rubber, plastic or nylon tubes. The diameter of these shall be based on vehicle application & should be chosen in such a way that air will be quickly exhausted from the circuit & should not create any back pressure . The routing of these ducting should be smooth without much of the bends to ensure smooth flow of the exhaust air. The exhaust of dual treadle valve (5) load sensing valve (6) relay valve (7) will have special arrangement to connect one end of the duct & clamp it. The air nozzle (17) will be made up of brass or steel material. The nozzle shall be screwed to dust shields in such a location that it can blow air in the gap between brake lining and drum. The nozzle shall be fit either cam shaft end or pivot end.

Figure 2 shows detailed parts used for nozzle fitment at camshaft end. The nozzle (17) having at least two outlets is fixed on the brake assembly dust shield ((25) using threaded sleeve (20) with the help of nuts (19). Then the duct (15 or 16) is connected to threaded sleeve (20). Clamp (21) is used for clamping duct on sleeve (20). Duct is clamped by bolt (23), spring washer (24) and nut (22). The Figure 3 shows fitment of nozzle in the brake assembly.
In Figure 3, a complete nozzle (17) fitment shows in brake assembly. It can be fitted either cam end or pivot end (Upper or lower side of the brake assembly).
Working:
The compressor (1) driven by engine, fills the air to front air tank (3) & rear air tank (4) to the designed system pressure during normal vehicle running. During braking situation, the brake pedal (18) will be pressed by the driver, which opens up dual treadle valve or foot brake valve (5) which is directly connected to front air tank (3). Now the air flows from dual treadle valve (5) to relay valve/quick release valve (7) giving signal to open air connection between rear air tank (4) to spring brake actuator LH & RH ( 10 & 11) through relay valve (7). The air flows from rear air tank (4) to spring brake actuator RH & LH (10&11) which in turn actuate rear foundation brakes (14). Simultaneously the air from front air tank (3) will flow to front brake chamber RH & LH (12 & 13) through dual treadle valve (5) and front foundation brakes (14) are actuated to apply brake.
When driver releases brake pedal (18) the air supplied to spring brake actuators (10&11) will be exhausted to the atmosphere through relay valve (7) or quick release valve (9) depending on design and air of actuators RH & LH (12 & 13) is released to the atmosphere through dual treadle valve (5).
In the modified brake circuit to remove brake lining dust, front duct (15) is added to connect exhaust of dual brake treadle valve (5) and nozzle (17) to front brake.. A rear

duct (16) is provided to connect exhaust of relay valve (7) or exhaust of quick release valve (9) to nozzle (17) at rear brakes. This exhausted air is blown to front brakes & rear brakes (14) through nozzles (17) as described above which removes brake lining dust. The pressure of the above said blown air will vary depending on intensity of the brake applied and diameter of the ducting arrangement for front brakes (15) & rear brakes (16). Generally, it will be more or less equal to brake application pressure ( ie the pressure supplied to spring brake actuators (10&11) & actuators RH & LH (12 & 13) ) which will vary from 0.5 bar to 7.5 bar ( in case of 8.1 bar vehicle system pressure) based on intensity of the braking, provided diameter of the ducting arrangement for front brakes (15) & rear brakes (16) is same as that of inlet to spring brake actuators (10&11) & actuators RH & LH (12 & 13)

WE CLAIM
1. A brake lining dust removal kit system comprising:
a first ducting arrangement connecting exhaust side of an air brake valve for front brakes to air nozzles provided proximal to front brakes;
a second ducting arrangement connecting exhaust side of an air brake valve for rear brakes to air nozzles provided proximal to rear brakes;
said air nozzle having at least one outlet fixed on a brake assembly dust shield provided on each of said front and rear brakes to blow exhausted air in the gap between brake lining and brake drum.
2. The system as claimed in claiml, wherein said air brake valve for front brakes is a dual treadle vale or foot brake valve.
3. The system as claimed in claiml, wherein said air brake valve for rear brakes is a relay valve or quick release valve.
4. The system as claimed in claim 1, wherein said air nozzle is fixed on said brake assembly dust shield using threaded sleeve and fastening means; and said first and second ducting arrangements are clamped to the respective other ends of said threaded sleeve.
5. The system as claimed in claim 1, wherein said air nozzle can be fitted either at cam
end or pivot end of said brake assembly.
6. The system as claimed in claim 1, wherein said first and second ducting arrangement is made of rubber, plastic or nylon tubes.
7. The system as claimed in claim 1, wherein the pressure of said blown exhausted air depends on intensity of the brake applied and diameter of said first and second ducting arrangement.

8. A vehicular braking system comprising a brake lining dust removal system as claimed in the preceding claims.
9. A brake lining dust removal system as hereinabove described with reference to the accompanying drawings.