Title of Invention

A DRYING AND DISTRIBUTION UNIT FOR USE IN THE CIRCUIT OF AN AIR BRAKE SYSTEM OF AN AUTOMOBILE

Abstract

A drying and distribution unit for use in the circuit of an air brake system of an autom obile comprising a dryer; a QSPV (quadruple system protection valve); a purge tank; a desiccant cartridge; a non-return valve connecting the air dryer to the QSPV; at least one air inlet port and a plurality of air delivery ports, wherein the components of the QSPV and the dryer body are oriented with respect to each other such that the components are directly attached at the side of the dryer body to substantially minimise overhang of the said QSPV; the purge tank is formed into a purge chamber located within the said body, surrounding the desiccant cartridge; the non-return valve is oriented downwardly from the purge chamber to the QSPV inlet port; and the said air inlet and delivery ports are positioned side by side on the said body

Full Text

This invention relates to a drying and distribution unit (DDU) for use in the circuit of an air brake system of an automobile. The DDU performs the following functions: * dries moist compressed air through a desiccant bed *maintains 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 tyre 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. Such known units (commonly called air processmg units) are "integrated", that is, the components of these units are constructed to achieve specific objectives including air drying function and air distributing functions. However, the known air procetising units have the drawbacks which are set out later herem below. This invention proposes to overcome such drawbacks, by proposing a better and more efficient construction. The drying and distribution unit (DDU) for use m the circuit of an air brake system of an automobile, according to this invention, comprises a dryer; a QSFV (a quadruple system protection valve); a purge tank; a desiccant cartridge; a non-return valve connecting the air dryer to the QSPV; at least one air inlet port and a plurality of air delivery ports, wherein the components of the QSPV and the dryer body are oriented with respect to each other such that the components are directly attached at the side of the dryer body to substantially minimise overhang of the said QSPV; the purge tank is formed into a purge chamber located within the said body, surrounding the desiccant cartridge; the non-return valve is oriented downwardly from the purge chamber to the QSPV inlet port; and the said air inlet and delivery ports are positioned side by side on the said body. This invention will now be described with reference to the accompanying drawings wherein Figs. 1 and 2 illustrate two different views of the known air processing units And Figs. 3 and 4 illustrate, by way of example, two different views of one of various possible embodiments of the DDU proposed herein. Figs. 1 and 2 illustrate a known ah* processmg unit. This consists of an and dryer A, an external purge tank T and a quadruple system protection valve (hereinreferred to as QSPV) commonly used m dual circuit and brake systems m motor vehicles. It will be observed from Figs. 1 and 2 that the QSPV mdicated by Q is spaced from the aur dryer A and that the QSPV and dryer are attached to each other by a flange F, giving rise to an overhang £. Consequently, during movement of the motor vehicle, the flange F QSPV Q experiences vibratory forces, created by such movement and by the overhangmg mass of the QSPV. Such a situation can lead to failure of the flange F and disruption of supply of air to the braking system or malfunctioning of the QSPV. in the known air processing unil, the purge tank T, externally located, is used for storing dry air. This tank is externally connected to the an- dryer A through a pipeline P. In the event of this pipeline being cut or inadvertently disconnected from, or left unconnected to, the air dryer, the desiccant in the air drying portion becomes fully saturated resulting in failure of the air drying operation. Furthermore, the purge air stored in the external purge tank cools to atmospheric temperature. Cold purge air has a reduced c^ability for regenerating the desiccant, resulting in lower drying efficiency. This is yet another disadvantage of the known air processing unit. The plumbing in the known air processing unit is also not satisfactory. Referring to Figs. 3 and 4 illustrating an integrated DDU in accordance with an embodiment of this invention, it will be observed that the QSPV is directly attached at the side of the dryer body at G by orienting the components S of the QSPV and the dryer body, to achieve this configuration. The flange F of the known air processing unit is eliminated. Besides, the total proximity of the QSPV to the dryer body eiiminateB overhang of the former wtti respect to the latter, to a considerable extent. The possibility of vibratory forces being amplified at the QSPV, doe to excessive overhang, virtually does not exist. Equally, flange failure is less likely to occur, because of the robustness of the flange used with considerably reduced overhang from the main body. In the embodiment illustrated, it will also be seen that the purge tank T of the known air processmg unit (Figs.l and 2) which is located outside the dryer is dispensed with. Instead, a purge chamber V, serving the same purpose as the purge tank T, is formed between the dryer-housing H and the desiccant cartridge C. The purge chamber V is thus located within the dryer body (unlike the purge tank T mounted outside the dryer body) and is directly connected to the air dryer purge passage internally, thus dispensmg with the provision of the pipe P of the known air processing unit mounted outside the dryer body. /5U f>i^se. ^*y ATAA.^ C«AJVUCPVW The possibility of the pipe P being cut or inadvertently disconttected from or left unconnected to the air dryer, as in the known au^ processing unit, does not at all arise. The nun-return vaive R is orienled downwardly from the purge chamber V to the QSPV inlet port; and the air inlet portN and delivery ports K are positioned side by side on the said body, thereby simplifymg the plumbing. The bracket for mounting the DDU on the chassis of the vehicle is indicated by M. The terms and expressions in this specification are of description and not of limitation, as these do not exclude any equivalents of the features illustrated and described, but various other embodiments of this invention are possible without departing from the scope and ambit of this mvention. We Claim: LA drying and distribution unit for use in the circuit of an air brake system of an automobile comprising a dryer; a QSPV (quadruple system protection valve); a purge tank a desiccant cartridge; a non-return valve connecting the air dryer to the QSPV; at least one air inlet port and a plurality of air delivery ports, wherein the components of the QSPV and the dryer body are oriented with respect to each other such that the components are directly attached at the side of the dryer body to substantially minimise overhang of the said QSPV; the purge tank is formed into a purge chamber located within the said body, surrounding the desiccant cartridge; the non-return valve is oriented downwardly from the purge chamber to the QSPV inlet port; and the said air inlet and delivery ports are positioned side by side on the said body 2. A drying and distribution unit for use in the circuit of an airbrake system of an automobile substantially as herein described and iliuslraled with reference to Figs. 3 and 4 of the accompanying drawings. Dated this the 30th day of June 2003

Documents:

538-che-2003-abstract.pdf

538-che-2003-claims duplicate.pdf

538-che-2003-claims original.pdf

538-che-2003-correspondnece-others.pdf

538-che-2003-correspondnece-po.pdf

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

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

538-che-2003-drawings.pdf

538-che-2003-form 1.pdf

538-che-2003-form 19.pdf

538-che-2003-form 26.pdf