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


TITLE OF THE INVENTION
Method of detecting contaminants in a fluid mixture
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatnia Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Asmita Sathaye and Suresh Patil both Indian nationals
of TATA MOTORS LIMITED an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatnia 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 contaminants detection in fluid mixture and more particularly it relates to a method of detecting contaminants in a fluid having different specific gravity.
BACKGROUND OF INVENTION
In automobile industry various types of fluids are used like brake fluid, transmission oil, fuel, refrigerant, engine oil etc. Various assemblies perform their function under specific environment of fluid. It is necessary that all the individual parts of these assemblies should be compatible and have good resistance to fluid in which it is operating.
For the automobile assembly comprising of rubber parts, often show the failures due to excessive swelling of the rubber parts. This could be because of reason that the basic rubber material or rubber grade is not resistant to the type of fluid under which it is to be operated. If in-spite of proper selection of the basic rubber material or rubber grade, failures are observed, then the cause could be because of contamination present in the fluid. If the fluid is contaminated and the selected rubber or rubber grade is not resistant to this contaminated fluid,, rubber material changes its physical & chemical properties. This contamination can adversely affect the system performance & reliability, causing failures like excessive wear, swelling, blockage causing degradation of the performance or malfunctioning.
In the case of brake system or clutch system, similar types of failure of rubber seals occur due to contamination of the brake fluid. This failure occurs due to swelling of
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said rubber seals present in the brake or clutch cylinder systems which are part of brake system or clutch system.
Practically there are chances of brake fluid getting mixed with steering oil due to similarity in their colours, viscosity, appearance or due to the proximity and similarity between the brake fluid reservoir and the power steering reservoir while manually filling the fluids in the reservoirs especially during top-up. Due to this mixing of two fluids in the brake or clutch system ,brake fluid gets contaminated. This can cause severe swelling of rubber seals present in the system. This is because of a special purpose rubber material is used in the brake system or clutch system which is resistant only to pure brake fluid and has very poor resistance to fluid which is contaminated due to mixing of steering oil.
Normally it is observed that the failure of the brake/clutch system is due to damaged /swollen rubber parts. As the rubber seals get damaged /swollen there is possibility of the brake / clutch system getting jammed or malfunctioning of the brake/clutch system..
If the vehicle brake system and clutch system failure is due to contamination of the fluid, then merely replacing the damaged or swollen parts of the brake /clutch system would not solve the problem entirely. There are chances of reoccurrence of the same problems if the same contaminated brake / clutch fluid is used or if proper practice for topping up of the brake fluid / clutch fluid is not followed.
There are various techniques to find out whether brake fluid is contaminated like centrifuging and visual inspection, Infrared spectrometer etc. Drawback associated in these methods is in order to analyze whether brake fluid is contaminated, special type of equipments / techniques are required which are costly.
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The present invention provides the solution to solve the problem from its root by developing the method which is easy, cost effective, which can be done in less time and can be done in house without any special device.
OBJECT OF INVENTION
The main object of the present invention is to provide a method of detecting contamination in the fluid having different specific gravity.
Another object of the invention is to provide a method of detecting contaminants in a fluid which is very simple and cost effective.
Another object of the invention is to provide a method of detecting contaminants in a fluid which can be done in house and comparatively within lesser time.
Another object of the invention is to provide a method of detecting contaminants in a fluid which can be carried out by any common person not having much technical knowledge in other words to provide a user friendly method of detecting contaminants.
Yet another object of this invention is to provide a method which can also be linked to the performance of the parts more particularly rubber components of the system.
STATEMENT OF INVENTION
Accordingly the present invention discloses method of detecting contaminants in the fluid mixture comprising the steps of:
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selecting the first fluid and second fluid for preparing mixture for carrying out the
test;
selecting the resilient member which is having excellent resistance to said first fluid
and low or moderate resistance to second fluid;
mixing the said first fluid and second fluid in various proportions;
immersing said resilient member in said mixture for predetermined time;
mechanical stirring of the said fluid mixture while its being heated for achieving the
homogeneity of said mixture;
monitoring the resilient member at regular interval till it floats in the said fluid
mixture.
BRIEF DESCRIPTION OF DRAWING
In accordance to the present invention,
figure 1 show the schematic diagram of the system used for detecting contaminants.
BRIEF DESCRIPTION OF INVENTION
In accordance with the present invention, method of detecting contaminants in a fluid comprising the step of:
• Selecting the first liquid and second liquid for preparing mixture for carrying out the test;
• Selecting the resilient member (rubber) which is having excellent resistance to said first liquid and low or moderate resistance to second liquid;
• Mixing the said first liquid and second liquid in various proportions;
• Immersing said resilient material (rubber) in said mixture for predetermined time;
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• Mechanical stirring of the said liquid mixture while its being heated for achieving the homogeneity of said mixture;
• Monitoring the resilient material at regular interval till it floats in the said liquid mixture.
Similarly the above steps can be repeated for carrying tests on various combinations of liquids and resilient material.
DETAILED DESCRIPTION OF INVENTION
Referring now to the drawing 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.
figure 1 show the schematic diagram of the system used for detecting contaminants.
In accordance with the present invention, Wherein said first fluid is a brake fluid having specific gravity of 1.048. Said second fluid is a steering oil having specific gravity of 0.847. Said brake fluid sample is mixed with steering oil sample in various proportions. Due to the difference in the specific gravity of brake fluid and steering oil, the specific gravity of the mixture was found to be decreasing with addition of steering oil ,as specific gravity of brake fluid is about 1.048 and that of steering oil is about 0.847. Since these two fluids are not miscible with each other, after some time two separate layers i.e brake fluid at bottom and steering oil at top are formed. However in the brake system, if brake fluid is contaminated with the steering oil, two separate layers are not formed as both the fluids get mixed thoroughly with each other due to rigorous movement of the fluid in the system while the vehicle is in motion and during operation of the brake system In order to simulate this condition in the laboratory and to keep the mixture homogenous, stirrer is used continuously. The type
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of rubber selected for ageing test is such a way that it has excellent resistance to brake fluid but has poor resistance to steering oil.
As the rubber sample has poor resistance to steering oil, it shows swelling in the mixture of brake fluid and steering oil and volume of the rubber increases in very short duration i.e. it gets swollen in the mixture. This indicates that rubber has absorbed steering oil and there is increase in weight and increase in the volume of the rubber. However as soaking period of the rubber in the contaminated fluid enhances, increase in the weight of rubber is not proportional to increase in the volume of the rubber Due to this rubber sample floats in the contaminated mixture after some time.
In accordance with the present invention, method of detecting contaminants in a fluid comprising the step of:
• Selecting the first liquid and second liquid for preparing mixture for carrying
out the test;
•' Selecting the resilient member (rubber) which is having excellent resistance to said first liquid and low or moderate resistance to second liquid;
• Mixing the said first liquid and second liquid in various proportions;
• Immersing said resilient material (rubber) in said mixture for predetermined time.
• Mechanical stirring of the said liquid mixture while its being heated for achieving the homogeneity of said mixture,
• Monitoring the resilient material at regular interval till it floats in the said liquid mixture.
Wherein mixing of said first fluid with second fluid in various proportion and heating along with stirring to achieve homogeneity since first and second fluid is not miscible without stirring , for carrying out tests, method comprising the step of;
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(a)
• Selecting the 70% of first fluid having specific gravity 1.048 and 30% of second fluid having specific gravity of 0.847 to make mixture having specific gravity 0.978
• Immersing said resilient material having specific gravity 1.14 (rubber) in the said mixture having specific gravity of 0.978
• Checking if said resilient material (rubber) till it floats in said mixture or not.
(b)
• Selecting the 75% of first fluid having specific gravity 1.048 and 25 % of second fluid having specific gravity of 0.847 to make mixture having specific gravity 0.995,
• Immersing said resilient material having specific gravity 1.14 (rubber) in the said mixture having specific gravity 0.995,
• Checking if said resilient material (rubber), till it floats in said mixture or not.
(c)
• Selecting the 80% of first fluid having specific gravity 1.048 and 20% of second fluid having specific gravity of 0.847 to make mixture having specific gravity of 0.998,
• Immersing said resilient material (rubber) having specific gravity 1.14 in the said mixture having specific gravity 0.998
• Checking if said resilient material (rubber), till it floats in said mixture or not.
(d)
• Selecting the 85% of first fluid having specific gravity of 1.048 and 15% of
second fluid having specific gravity 0.847 to make mixture having specific
gravity of 1.010.
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• Immersing said resilient material (rubber) having specific gravity 1.14 in the said mixture having specific gravity 1.010,
• Checking if said resilient material (rubber) till it floats in said mixture or not.
(e)
• Selecting the 90% of first fluid having specific gravity of 1.048 and 10% of
second fluid having specific gravity of 0.847 to make mixture having specific
gravity of 1.030.
• Immersing said resilient material (rubber) having specific gravity 1.14 in the said mixture having specific gravity 1.030.
• Checking if said resilient material (rubber) till it floats in said mixture or not.
(0
• Selecting the 95% of first fluid having specific gravity of 1.048 and 5% of
second fluid having specific gravity of 0.847 to make mixture having specific
gravity of 1.028,
• Immersing said resilient material (rubber) having specific gravity of 1.14 in the said mixture having specific gravity of 1.028
• Checking if said resilient material (rubber) till it floats in said mixture or not.
(g)
• Selecting the 100% pure first fluid having specific gravity of 1.048,
• Immersing said resilient material (rubber) having specific gravity of 1.14 in the said 100% pure first fluid,
• Checking if said resilient material (rubber) is floating in said first fluid.
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From the above steps for carrying out tests it is observed that the present invention is able to detect the contaminants even if 5% of second fluid is used in the mixture as rubber sample flaots in the contaminated mixture. In case of 100% of first fluid without contamination, the said rubber material has neither shown floating nor swelling even after long time for example 72 hours.
As rubber sample floating observed from the practical tests carried out in mixture with different percentage of first fluid and second fluid, it is seen that even with very less percentage of contaminant present in the mixture the rubber sample floats in the mixture. Thus if the first fluid is contaminated even by very less quantity of second fluid the contamination in the mixture can be detected easily and efficiently by present invention.
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WE CLAIM
1. Method of detecting contaminants in the fluid mixture comprising the steps of:
selecting the first fluid and second fluid for preparing mixture for carrying out the test;
selecting the resilient member which is having excellent resistance to said first fluid and low or moderate resistance to second fluid;
mixing the said first fluid and second fluid in various proportions;
immersing said resilient member in said mixture for predetermined time;
mechanical stirring of the said fluid mixture while its being heated for achieving the homogeneity of said mixture;
monitoring the resilient member at regular interval till it floats in the said fluid mixture to check said mixture for contamination.
2. The method as claimed in claim 1, wherein said resilient member is a rubber having excellent resistance to said first fluid and low or moderate resistance to said second fluid.
3. The method as claimed in any one of the preceding claims, wherein said first fluid is the brake Fluid.
4. The method as claimed in any one of the preceding claims, wherein said second fluid is the steering oil.
5. The method as claimed in any one of the preceding claims, wherein said mechanical stirring is done by power operated stirrer.
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6. Method of detecting contaminants in the fluid mixture substantially as hereinabove described with reference to the accompanying drawings.