|Title of Invention||
BREATHING ARRANGEMENT OF BRAKE CHAMBER OF A MOTOR VEHICLE
|Abstract||This invention relates to the unidirectional check valve used in brake actuators in the air brake system. In the conventional system the brake actuators are provided with breather holes to facilitate breathing of air as well as draining of water collected inside the chamber. As the breather holes are exposed to atmosphere, it leads to entry of dust and mud thereby leading to reduced life of internal components. The object of invention is to overcome the aforesaid problem. The solution resides in the unidirectional check valve arrangement, which prevents dust, and mud water entry at the same time facilitates breathing and draining of water.|
Field of invention
This invention relates to the unidirectional check valve used in brake actuators in the air brake system. The brake actuators are fitted very near to the ground and for that matter very much exposed to dusty and muddy environments. In conventional system the brake actuators are provided with breather holes to facilitate breathing of air as well as draining of water collected inside the chamber. As the breather holes are exposed to atmosphere, it leads to entry of dust and mud thereby leading to reduced life of internal components. The object of invention is to overcome the aforesaid problem. The solution resides in the unidirectional check valve arrangement, which prevents dust, and mud water entry at the same time facilitates breathing and draining of water. Prior art
Brake chambers are known to the prior art. However the prior art has the following disadvantages.
1. In the prior art products breathing takes place through the breather hole, which is exposed to atmosphere. These breather holes, at the time of breathing intakes dust and mud depending on the environment. These particles getting inside the brake chamber reduces the life of the internal parts especially the diaphragm.
2. Certain other prior art brake chambers make use of reduced no. of breather holes for breathing and water draining purposes and use bellows for sealing purpose. But these brake chambers also are exposed to dust and muddy environments and thereby prone to dust entry
The inventors have made great effort to provide a device, which meet the requirement of the industry and overcome the problem associated in the prior art.
To achieve the above object according to first aspect and feature of the present invention there is provided a device to improve, efficiency,
According to second aspect and feature of the invention in addition to the first feature the invention comprises a device, which is unique, rugged efficient and economical.
At the outset of the description that follows, it is to be understood that ensuring description only illustrate a particular form of this invention. However, such particular form is only an exemplary embodiment without intending to imply any limitation on the scope of this invention. Accordingly, the description is to be understood as an exemplary embodiment and reading of the invention is not intended to be taken restrictively.
The above and other objects features and disadvantages will be clear from the following description of preferred embodiment taken in conjunction with accompanying drawings.
The foregoing description is outlined rather broadly preferred and alternative feature of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing and modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should realize such equivalent conception do not depart from the spirit and scope of the invention in its broadest form.
This invention relates to the incorporation of unidirectional check valve used in brake actuators in the air brake system. The check valve is constructed in such a way that it integrates the following functions
1. It facilitates breathing of air during actuation of the piston
2. It facilitates draining of water that gets collected inside the chamber
3. It seals the breather hole against dust and water during normal condition Installation of the check valve leads to a problem. The problem being at the time of
return stroke, there are no means to allow air into the chamber so as to neutralize the vacuum generated. The problem is overcome by incorporation of bellows having holes. These holes are normally covered by virtue of the fact that at the normal condition the bellows are in compressed condition, thereby the holes in the bellows are closed. During the period of actuation, the bellows expand resulting in opening of holes, which results in allowing of air into the chamber. Only at the time of actuation of the brake, there is a possibility of dust entering into the chamber and rest of the period there is no possibility of dust entering into the chamber. It has been tested as per dust test standard, wherein it has been found out that there is 70% reduction in the dust formation compared to design without bellows and where in breather holes are normally provided. Brief description of drawings
The accompanying drawings are intended to provide further understanding of invention and are incorporated in and constitute a part of invention. The drawings illustrate an embodiment of invention and together with the description illustrate principle of invention.
The drawings should not be taken as implying any necessary limitation on the essential scope of invention.
The drawings are given by way of non-limitative example to explain the nature of the invention.
For a more complete understanding of the instant invention reference is now made to the following description taken in conjunction with accompanying drawings.
The various features of novelty, which characterize the invention, are pointed out specifically in the claims, which form part of description. For a better understanding of the invention, its operating advantage, specific objects obtained by its use, reference should be made to the drawings and descriptive matter is which there are illustrated and described preferred embodiments of invention.
Referring now to drawings, where like numerals and alphabets designate identical or corresponding parts throughout the referred views,
Figure-1 of the drawings shows in cross section the conventional brake chamber. Figure-2 of the drawings shows in cross section the brake chamber with check valve arrangement.
Figure-3 of the drawings shows the check valve arrangement in two different orientations. Figure-4 of the drawings shows the sealing feature of the check valve arrangement during the return stroke of the brake chamber
Figure-5 of the drawings shows the water draining function of the check valve arrangement.
Detailed description of preferred embodiment of invention
The Brake Chamber consists of a pressure plate (1) with a facility of air inlet connection, (A), Non pressure plate (2), Piston assembly (3), diaphragm (4) clamped between the non-pressure plate and the pressure plate using a clamp ring (5), and a return spring (6). Breather holes B1 and B2 are provided to facilitate breathing. The breather hole (B1) of the chamber facing towards the ground is intended for draining of water. When air pressure is applied through the port (A), the diaphragm(4) deflects and pushes the piston assembly (3) against the return spring (6) in the direction of (D). The counter pressure that develops in the non-pressure side (C) of the brake chamber during
actuation, is neutralized by means of the breather holes provided in the non pressure plate
The breathing arrangement pertaining to this invention and consists of a check valve (V) assembled to the brake chamber and facing towards the ground. The check valve consists of a flap (F) which seals the Non pressure plate breather hole (H) in the normal condition. The check valve (V) is held on to the non-pressure plate (2) my means of the snap lugs (L) provided. Two slots (S) are provided in the snap lugs to facilitate draining of water. When air pressure is applied through the port (A), the diaphragm deflects and pushes the piston assembly (3) against the return spring (6) in the direction of (D). The pressure developed inside the chamber due to the volume change in the non-pressure side (C) of the chamber opens the flaps (F) and airflows out of the chamber denoted by arrow-X. When the air pressure is released, the piston assembly (3) is returned back to the rest position due to the return spring (6). The pressure difference is neutralized by virtue of the air intake into the non-pressure side (C) through the holes (R) provided in the bellow (7). The flap (F) of the check valve remains closed and prevents dust entry into the chamber. The water-draining feature of the check valve is explained in figure-5. Water that enters into the brake chamber flows through the slots (S) provided in the check valve and get collected inside the flap (F) of the check valve. Water gets discharged when the flap opens at the time of actuation ensuring no residual collection of water inside the chamber. The invention has been explained in relation to specific embodiment. It is inferred that the foregoing description is only illustrative of the present invention and it is not intended that the invention be limited or restrictive thereto. Many other specific embodiments of the present invention will be apparent to one skilled in the art from the foregoing disclosure. All substitution, alterations and modification of the present invention, which come within
the scope of the following claims, are to which the present invention is readily susceptible without departing from the spirit of the invention.
The scope of the invention should therefore be determined not with reference to the above description but should be determined with reference to appended claims along with full scope of equivalents to which such claims are entitled.
1. A breathing arrangement for the brake actuator in an air brake system of a motor vehicle, which comprises a unidirectional check valve, which facilitates breathing, prevents dust and mud water entry into the chamber and at the same time facilitates draining of water that gets collected inside the chamber.
2. A breathing arrangement for the brake actuator in an air brake system of a motor vehicle as claimed in claim-1 wherein the check valve has separate provision for entry of water and the water entered is being collected at the bottom of the check valve and being discharged when the flap opens at the time of actuation ensuring no residual collection of water inside the chamber.
3. A breathing arrangement for the brake actuator in an air brake system of a motor vehicle as claimed in claim-1 wherein the holes in the bellows are such that during compressed condition of the bellows the holes are closed and in the expanded condition of the bellows the holes are kept open, allowing atmospheric air to enter into the chamber.
4. A breathing arrangement for the brake chamber in an air brake system of a motor vehicle claimed in claim-1 as described in the complete specification and as illustrated by way of drawings.
|Indian Patent Application Number||626/CHE/2004|
|PG Journal Number||44/2011|
|Date of Filing||01-Jul-2004|
|Name of Patentee||WABCO-TVS (INDIA) LIMITED|
|Applicant Address||NO.29 HADDOWS ROAD,CHENNAI 600 006|
|PCT International Classification Number||B60T13/26|
|PCT International Application Number||N/A|
|PCT International Filing date|