Title of Invention	A FILTER FOR A DRYING AND DISTRIBUTION USED IN THE CIRCUIT OF AN AIR BRAKE SYSTEM OF AN AUTOMOBILE
Abstract	A filter for the drying and distribution unit (DDU) used in the circuit of an air brake system of an automobile comprising a porous filter pad for being placed against the air inlet surface of the said cartridge to cover the said surface including the centrally perforated region of the said surface; a retainer disc for being placed against the filter pad, to sandwich the filter pad between the retainer disc and the said surface, said retainer disc having peripherally disposed spaced resilient fins, the air to be filtered passing through the spaces between the fins into the filter pad, transversely to the body of the said pad and then in a right angular direction along the said body to fmally enter the said cartridge at the perforated region, thus increasing the length of flow of air through the filter pad and thereby improving the oil filtering.

Title of Invention

A FILTER FOR A DRYING AND DISTRIBUTION USED IN THE CIRCUIT OF AN AIR BRAKE SYSTEM OF AN AUTOMOBILE

Abstract

A filter for the drying and distribution unit (DDU) used in the circuit of an air brake system of an automobile comprising a porous filter pad for being placed against the air inlet surface of the said cartridge to cover the said surface including the centrally perforated region of the said surface; a retainer disc for being placed against the filter pad, to sandwich the filter pad between the retainer disc and the said surface, said retainer disc having peripherally disposed spaced resilient fins, the air to be filtered passing through the spaces between the fins into the filter pad, transversely to the body of the said pad and then in a right angular direction along the said body to fmally enter the said cartridge at the perforated region, thus increasing the length of flow of air through the filter pad and thereby improving the oil filtering.

Full Text	This invention relates to a coalesving filter and retainer for the drying and distribution unit (DDU) used in the circuit of an airbrake system of an automobile. The DDU performs the following functions: * dries moist compressed air through a desiccant bed mamtains system pressure within a required range * distributes compressed air to different circuits of the brake system and protects and allows functioning of the healthy circuits of the system, in case of partial failure of the system. * stores dried air for the regeneration of desiccant through purging. in addition to the above function, a type inflator and safety valve are also included in the said unit. The compressed air control and distribution function mentioned above is achieved through mechanically actuated valves, which in turn receive appropriate pneumatic signals. The compressed air from the compressor of the air brake system contains oil particles from the compressor lubricating system and is fully saturated with water vapour. When the moist air passes through the desiccant bed of the DDL), the moisture is adsorbed on the desiccant surface, thus drying the air. When the set system pressure is reached, the compressor is cut out or the compressor delivery is directed to atmosphere In this phase a small amount of dried air stored is re-expanded over the desiccant bed in the reverse direction, which removes the adsorbed moisture and expels it to the atmosphere. Consequently, the desiccant bed is dry again, ready for the next charging cycle. The coalescing filter is a pre- filter which removes the oil and other contaminants from the compressor air before it enters the desiccant bed, allowing only air with water vapour to enter the desiccant bed. The oil and contaminants, if not removed, will coat the desiccant surface and adversely affect its capability to adsorb moisture effectively on its surface, significantly reducing the service life of the DDU. The effectiveness of the coalescing filter is therefore very important to the functioning of the DDU. This invention therefore proposes a filter for a DDU which provides a better and more efficient filtering action than that of several filters known to the art. The filter for the drying and distribution unit used in the circuit of an airbrake system of an automobile, according to this invention, comprises a porous filter pad for being placed against the air inlet surface of the said cartridge to cover the said surface including the centrally perforated region of the said surface; a retainer disc for being placed against the filter pad, to sandwich the filter pad between the retainer disc and the said surface, said retainer disc having peripherally disposed spaced resilient fins, the air to be filtered passing through the spaces between the fins into the filter pad, transversely to the body of the said pad and then in a right angular direction along the said body to finally enter the said cartridge at the perforated region, thus moreasing the length of flow of air through the filter pad , thereby improving the oil filtering. This invention will now be described with reference to the accompanying drawings which illustrate by way of example one of various possible embodiments of die filter proposed herein, Fig.l illustrating a DDU in accordance with our invention and showing the said embodiment of the filter in position And Fig.2 separately illustrating the said embodiment of the filter and the desiccant cartridge A porous filter pad F is intended for being placed against the air inlet surface A of the said cartridge C to cover the said surface including the perforated region B of the said surface. The perforated region B has the perforations or openings D through which the air, after passing through the filter pad F, enters into the desiccant cartridge C of the DDU. A retainer disc R is intended for being placed against the filter pad F to sandwich the filter pad between the retainer disc R and the air inlet surface A. The retainer disc has peripherally disposed spaced resilient fins T, the air to be filtered passing through the spaces S between the fins T into the filter pad, transversely to the body of the said pad (as indicated by the arrow H) and then in a right angular direction along the said body (as indicated by the arrow J) to finally enter the said cartridge at the perforated region B (as indicated by the arrow K). in Fig. 2 the filter pad F is shown displaced from the surface A and the retainer ring R for the sake of clarity in the description of their operation. In actual use, the filter pad will be tightly sandwiched between the air inlet surface A of the desiccant cartridge and the retainer R. The spaced resilient fins F of the retainer R are bent at L to keep the filter pad F securely in place without sliding away in use. These fms furnish the requisite grip on the periphery of the filter pad F to retain it firmly in position against vibration forces. The terms and expressions herein are of description and not of limitation, as these do not exclude any equivalents of the features illustrated and described, since various other embodiments of the filter proposed herein are possible without departing from the scope and ambit of this invention. We Claim: 1. A filter for the drying and distribution unit (DDU) used in the circuit of an air brake system of an automobile comprising a porous filter pad for being placed against the air inlet surface of the said cartridge to cover the said surface including the centrally perforated region of the said surface; a retainer disc for being placed against the filter pad, to sandwich the filter pad between the retainer disc and the said surface, said retainer disc having peripherally disposed spaced resilient fins, the air to be filtered passing through the spaces between the fins into the filter pad, transversely to the body of the said pad and then in a right angular direction along the said body to fmally enter the said cartridge at the perforated region, thus increasing the length of flow of air through the filter pad and thereby improving the oil filtering. 2. A filter as claimed in Claim 1 wherein the fins of the retainer are bent at their ends to hold the filter pad securely in place, against vibration forces, without sliding away in use. 3. A filter for the drying and distribution unit (DDU) used in the circuit of an air brake system of an aulomobite substantially as herein described and illustrated. Dated this the 30 th day of 2003

Full Text

This invention relates to a coalesving filter and retainer for the drying and distribution unit (DDU) used in the circuit of an airbrake system of an automobile.
The DDU performs the following functions:
* dries moist compressed air through a desiccant bed mamtains system pressure within a required range
* distributes compressed air to different circuits of the brake system and protects and allows functioning of the healthy circuits of the system, in case of partial failure of the system.
* stores dried air for the regeneration of desiccant through purging.
in addition to the above function, a type inflator and safety valve are also included in the said unit.
The compressed air control and distribution function mentioned above is achieved through mechanically actuated valves, which in turn receive appropriate pneumatic signals.
The compressed air from the compressor of the air brake system contains oil particles from the compressor lubricating system and is fully saturated with water vapour. When the moist air passes through the desiccant

bed of the DDL), the moisture is adsorbed on the desiccant surface, thus drying the air. When the set system pressure is reached, the compressor is cut out or the compressor delivery is directed to atmosphere In this phase a small amount of dried air stored is re-expanded over the desiccant bed in the reverse direction, which removes the adsorbed moisture and expels it to the atmosphere. Consequently, the desiccant bed is dry again, ready for the next charging cycle.
The coalescing filter is a pre- filter which removes the oil and other contaminants from the compressor air before it enters the desiccant bed, allowing only air with water vapour to enter the desiccant bed. The oil and contaminants, if not removed, will coat the desiccant surface and adversely affect its capability to adsorb moisture effectively on its surface, significantly reducing the service life of the DDU. The effectiveness of the coalescing filter is therefore very important to the functioning of the DDU.
This invention therefore proposes a filter for a DDU which provides a better and more efficient filtering action than that of several filters known to the art.

The filter for the drying and distribution unit used in the circuit of an airbrake system of an automobile, according to this invention, comprises a porous filter pad for being placed against the air inlet surface of the said cartridge to cover the said surface including the centrally perforated region of the said surface; a retainer disc for being placed against the filter pad, to sandwich the filter pad between the retainer disc and the said surface, said retainer disc having peripherally disposed spaced resilient fins, the air to be filtered passing through the spaces between the fins into the filter pad, transversely to the body of the said pad and then in a right angular direction along the said body to finally enter the said cartridge at the perforated region, thus moreasing the length of flow of air through the filter pad , thereby improving the oil filtering.
This invention will now be described with reference to the accompanying drawings which illustrate by way of example one of various possible embodiments of die filter proposed herein,
Fig.l illustrating a DDU in accordance with our invention and showing the said embodiment of the filter in position

And
Fig.2 separately illustrating the said embodiment of the
filter and the desiccant cartridge
A porous filter pad F is intended for being placed against the air inlet surface A of the said cartridge C to cover the said surface including the perforated region B of the said surface. The perforated region B has the perforations or openings D through which the air, after passing through the filter pad F, enters into the desiccant cartridge C of the DDU.
A retainer disc R is intended for being placed against the filter pad F to sandwich the filter pad between the retainer disc R and the air inlet surface A.
The retainer disc has peripherally disposed spaced resilient fins T, the air to be filtered passing through the spaces S between the fins T into the filter pad, transversely to the body of the said pad (as indicated by the arrow H) and then in a right angular direction along the said body (as indicated by the arrow J) to finally enter the said cartridge at the perforated region B (as indicated by the arrow K).

in Fig. 2 the filter pad F is shown displaced from the surface A and the retainer ring R for the sake of clarity in the description of their operation. In actual use, the filter pad will be tightly sandwiched between the air inlet surface A of the desiccant cartridge and the retainer R.
The spaced resilient fins F of the retainer R are bent at L to keep the filter pad F securely in place without sliding away in use. These fms furnish the requisite grip on the periphery of the filter pad F to retain it firmly in position against vibration forces.
The terms and expressions herein are of description and not of limitation, as these do not exclude any equivalents of the features illustrated and described, since various other embodiments of the filter proposed herein are possible without departing from the scope and ambit of this invention.

We Claim:
1. A filter for the drying and distribution unit (DDU) used in the circuit of an air brake system of an automobile comprising a porous filter pad for being placed against the air inlet surface of the said cartridge to cover the said surface including the centrally perforated region of the said surface; a retainer disc for being placed against the filter pad, to sandwich the filter pad between the retainer disc and the said surface, said retainer disc having peripherally disposed spaced resilient fins, the air to be filtered passing through the spaces between the fins into the filter pad, transversely to the body of the said pad and then in a right angular direction along the said body to fmally enter the said cartridge at the perforated region, thus increasing the length of flow of air through the filter pad and thereby improving the oil filtering.
2. A filter as claimed in Claim 1 wherein the fins of the retainer are bent at their ends to hold the filter pad securely in place, against vibration forces, without sliding away in use.
3. A filter for the drying and distribution unit (DDU)
used in the circuit of an air brake system of an

aulomobite substantially as herein described and illustrated.
Dated this the 30 th day of 2003

Documents:

536-che-2003-abstract.pdf

536-che-2003-claims duplicate.pdf

536-che-2003-claims original.pdf

536-che-2003-correspondnece-others.pdf

536-che-2003-correspondnece-po.pdf

536-che-2003-description(complete) duplicate.pdf

536-che-2003-description(complete) original.pdf

536-che-2003-drawings.pdf

536-che-2003-form 1.pdf

536-che-2003-form 19.pdf

536-che-2003-form 26.pdf

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Patent Number

198897

Indian Patent Application Number

536/CHE/2003

PG Journal Number

23/2006

Publication Date

09-Jun-2006

Grant Date

21-Feb-2006

Date of Filing

30-Jun-2003

Name of Patentee

M/S. SUNDARAM CLAYTON LIMITED

Applicant Address

JAYALAKSHMI ESTATES, NO.8 HADDOWS ROAD, CHENNAI 600 006

Inventors:

#	Inventor's Name	Inventor's Address
1	NE	NE

PCT International Classification Number

N/A

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA