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


"Dust Cover for restricting the dust and dirt ingress in the two way fuel tank pressure valve with air as working medium**
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
INVENTOR
Mr. Sudeep Deepak Sane an Indian national
of TATA MOTORS LIMITED an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention


FIELD OF INVENTION
This invention relates to the plastic dust cover aimed to prevent a two way tank pressure valve operating on air as a working medium from dust ingress.
BACKGROUND OF INVENTION
The dust cover in this invention serves its function of preventing the dust ingress in the lank pressure valve. The valve needs protection from dust/dirt / mud like things. The dust/ dirt/mud must be prevented from entering into the valve, which otherwise may cause a malfunctioning of the valve. The malfunctioning may cause the valve to block or function abnormally, which in turn will affect the allied system malfunctioning. The dust cover is aimed at preventing the ingress of such things into the valve.
OBJECTS OF INVENTION
The above stated dust cover serves its function by preventing the dust entry into the two-way tank pressure valve. The two-way valve stated in this regard needs protection from dust/dirt / mud like things. The dust cover is aimed at preventing the ingress of such things into the valve.
BRIEF DESCRIPTION OF INVENTION
The cover, as stated earlier, provides protection to the valve from dust/ dirt ingress. The cover is made up of plastic. It functions in a simple manner by providing a zigzag air entry path which in turn acts as a passive dust entry restrictor.
BRIEF DESCRIPTION OF DRAWINGS

Fig. 1- shows an application of dust cover
Fig. 2- shows the details of the present invention

Fig. 3 -shows the passage of air ingress into the valve & dust cover shown in cross
sectional view of the present invention
Fig. 4 - shows the front perspective view of dust cover for the valve of the present
invention
Fig. 5 - shows the rear perspective view of dust cover for the valve of the present
invention
DETAILED DESCRIPTION OF INVENTION
In general, certain components are intended to be protected from dust/dirt etc while on field applications. Such components may fail to perform or to serve their intended purpose if they come in contact with dust/dirt. etc. the dust cover intended to be disclosed deals with the valves or pipes or any structure which has to work on air to perform its function.
The Dust Cover can offer a passive inhibition to the dust/dirt entry into the valve or the system. The typical construction of the dust cover ensures that the air entering into the system follows a zig zag path so that the dust gets settled down or gels blocked prior to the concerned entry port.
One such application is shown with the help of images.
The dust cover (]) is preventing the entry of dust/dirt in a two way valve which is intended to operate with air as a medium. Referring to Fig. 2, the two way valve (2) serves the purpose of normal operation of an automobile fuel tank(4) . In common practice the concept of dust cover (1) can be used in various places wherein we have air as a working fluid.
Referring to fig.l which shows vehicle level view of the invention, the detail A reveals a particular zone which encompasses of the fuel tank (4), vehicle undcrbody (5). dust cover( 1) and a two way valve (2).


The area outside the cab of an automobile is often exposed to dust/ dirt etc. the systems which work on air as a working medium, often stand chance of dust ingress. They often need to be protected from the same, as the dust ingress may cause deterioration in performance. The dust cover (1) in this application protects the two way valve (2) from direct entry of dust.
The details of dust cover are shown in the detail A.
The dust cover (1) is very simple in construction. It has two concentric cylinders (10) and (11) with a central zone of one end closed. The two concentric cylinders arc attached to a single face (12), the inner cylinder(lO) being shorter in length than the outer one(l1). The inner and outer cylinder is joined by the ribs (9). The slots for air ingress (8) are provided on the surface (12) (mentioned earlier) between the zone from outer cylinder (11) to inner cylinder (10). The slots are provided on the outer periphery of one end. The other end is open and has an arrangement for snap fitting the valve. The construction of the cover can even vary from circular to square to any other cross sections. For this application, the parent valve has a circular shape, hence the dust cover(l). The parent valve is a two way valve (2) which works within certain predefined pressure cut off settings. This valve lets in or passes out the air from the fuel tank once the pressure limits are reached. This in turn helps in maintaining the pressure in the fuel tank (4) close to atmosphere.
The snap fit arrangement in this case is desired for easy assembly and dis assembly. However any other arrangement can also be used to affix the dust cover to the parent system.
After the valve is snap fitted, the air path is zig-zag, which in turn acts as a passive dust/dirt/mud restrictor. The detail is revealed from Fig.3.

Also if some amount of dust/dirt/mud gets into the cover, it will be prevented from entry into the valve tip, in such a condition some part of air entry slots are stil) open so that the valve functioning does not get hampered. The material for the dust cover construction may be nylon or PU etc. depending on the surrounding conditions. There is no specific material necessary for the part to function.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.
Dated this 30th day of March 2009

Karuna Goleria of DePENNING & DePENNING
TATA MOTORS LIMITED By their Agent & Attorney