Title of Invention

MODIFIED CUT OFF VALVE ASSEMBLE IN C3W TYPE DISTRIBUTOR VALVE USED IN RAILWAYSAIR BRAKE SYSTEMS

Abstract ABSTRACT. APPLICATION NO.MAS/1391/97 DATED 25/08/1997 TITLE : MODIFIED CUT OFF VALVE ASSEMBLY IN C3V TYPE DISTRIBUTOR VALVE USED IN RAILWAYS AIR BRAKE SYSTEMS. This invention relates to an improved distributor valve (Type (3U} which is nost critical controlled valve in the entire brake tysteas and governs the very braking functions' in a particular vehicle, be It a locoaotive, a wagon or a coach. The distributor valve in the invention relates to iaproved aodified cut-off valve sub-asseably in the known art of distributor valve.
Full Text

This Invention retates to an Improved "DISTRIBUTOR VALVE' (Type C3W) which is most critical controlled valve In the entire brake systems and governs the very "BRAKING FUNCTIONS' in a particufar vehicle, be it a locomotive, a wagon or a coach.
The operation of the brake on a vehide is Controlled by a triple valve so called because it has three functions- to release the brake, to apply the brake and to hold it at the current level of application.
Typically a triple valve contains a slides valve which detects the changes in the brake pipe pressure and rearranges, the connections inside the valve accordingly. It either recharges the Auxiliary reservoir and opens the brake cylinder exhaust, close the brake cylinder exhaust and allows the Auxiliary reservoir air to feed into ttte brake cylinder or holds the air pressure in the Auxiliary reservoir and brake cylinder at the current level.
A distributor valve performs same function as the triple valve. It is just a sophisticated version. Distributors have the ability to connect an emergency reservoir to the brake system on the vechile and to recharge it. Distributors may also have a partial release facility something not usually available with triple valves.
A mod^n disfcribytor will have :
a quick service feature - where a small chamber inside the distributor is used to accept brake pipe air to assist in the transmission of pressure reduction down the train

a reapplication feature - allowing the brake to be quickly re-applled after a partial release a graduated release feature - allowing a partial miease followed by a holding of the lower application rate
a connection for a variable load valve - allowing brake cylinder pressure to adjust tothe weight of the vehicle chokes (which can be changed) to allow variations in brake application and release times an in shot feature - to give an initial quick application to get the blocks on the wheels brake cylinder pressure limiting Auxiliary reservoir overcharging prevention.
All of these features are achieved with no electrical Control. The Control systems comprise diaphragms and springs arranged in a series of complex valves and passages within the steel valve block. Distributors with ail these features will normally be provided on passenger trains or specialist high speed freight vehides.
Compressed air pressure charges into distributive valve from the brake pipe of the vehicle.
The basic principle of operation of braking system Is as follows:
_ compressed air produced In the locomotive;
_ the compressed air is transmitted through pipes from wagon to
wagon;
the valve receives the compressed air;
the valve stores the compressed air in Auxiliary Reservoir (100 litres
volume) and Control reservoir (6 litres volume)
each time the air brake Is applied the compressed air stored from
Auxiliary Reservoir is drawn.
when the brake Is released the distributor valve once again tops-up
the depleted air storage level in Auxiliary Reservoir to its original level.
So at all times the compressed air is stored in readiness In Auxiliary
Reservoir for subsequent brake application.



«
the fine dust partldes get settled In orifice, charging time will keep increasing and after a period of time due to continuous deposit of fine dust and other Ingress picked up by the compressed air from the pipes, the distributor would malfunction totally since it may not be able to charge its reservoir due to completely blocked JET SOLDC". Due to Improper Installation, improper maintenance practice as well as frequent failure of filter, dusty air manages to get into the valve.
During the periodic Performance - Evaluation of the distributor valve TYPE C3W it has been reported that malfunctioning is due to Control Reservoir not getting charged by the distributor valve. On Investigation it was found that there is no defective component or damage to any part of the distributor other than on "JET SOLEX*. The problem noticed was the deposit of external dust on the orifice and subsequent blockage of this passage which makes the valve inoperative. When the JET SOLEX Is cleaned and the valve Is re-assembled, the performance was observed to be quite satisfactory. Attemptsin en;largement of orifice from 0.42mm to 0.8 mm, not only allow dust to pass through but reduce the charging time to half its stipulated time. So this attempt of modification did not yield the desired performance of ttie valve with respect of charging time
More particularly the Improved "DISTRIBUTOR VALVE" according to the inva^on rdates t» improved 'MODIFIED COT OFF VALVE" sub-assembly In the Distributor Valve already in usage by Railways.
This invention also relates to elimination of the component *JET SOLEX", enlargement of ORIFICE, redesign of few other related components to maintain the specified performance of the vatve after these modifications.
The Cut off Valve Sub-assembly according tx) ttie Invention has been described hereinabove in relation to Railway vehicle. Without departing from the scope and spirit of Invention the said Cut off Valve Sub-assembly is easily adapted for the br^'ng function in a k>comotive, a wagon or a coach.

There is a minor difference In braldng needs of locomotives, coaches and wagons. All these braldng needs involve the usage of distributor valve. Majority of the components are common and also the very design principles behind the vaive operating medianism is common.
For example :
In freight trains carrying heavy pay loads the valve Is designed for longer lengths but travel at lower speeds.
In passenger trains carrying passengers the valve is designed for shorter lengths tnit travel at higher speeds.
All valves have to conform to the stipulations by the Research Designs and Standard Organisation In the Railway industry
The Cut off Valve Sub-assembly according to the Invention provides for the better and desired performance of the valve by adiieving the stipulate! charge rate. This charging rate into the reservoir Is governed by a sub-assembly inside the distributor valve called *Cut off Valve". This Cut off Valve Is designed with modifications as specified herein.
The Cut off Valve Sub-assembly consists of a number of finely machined components^ some bonded with special quality rubber material and assembled Into a compact unit with the help o stainless steel springs.
In this invention to provide the desired performance of distributor valve the Invention related to redesign of whole SUB ASSEMBLY OF CUT OFF VALVE by eliminating the very component JET SOLEX which was playing a major role In the old version. The modified version of the Cut off Valve Sub-assembly has the

enlarged orfice size of 1,6 mm so that does can never get trapped in the passage. With this enlargement dust accumulation problem has been overcome but other modifications are made to maintain the stipulated diarging time of the valve.
In this invention as mentioned above the main modification Is the introduction of choke M6 orifice 1.66 mm size and elimination of component JET SOLEX, spring and spring seats and redesign of certain components. The stopper pluug, valves spring seats are redesigned to suit the requirment of the new orifice. The components drdip and one spring are used as in the oid version without any modification. An additional new spring is part of the new modified version of the invention.
DESCRIPTION OF THE INVENTION WITH REFERENCE TO DRAWINGS:-
Now the invention will be described In detail with reference to the accompanying drawings :-
Bg i tiiustrates the s&dikmsA view (rf Cut crff valve sub assembly in distributor valve wjtii reference numerals according tx> the invention and parts of tiie reference numerals with deso'iption is tabulated below.
Rg 2 A:- illustrates the sectional view of Cut off valve sub assembly in distributor valve of the existing ait witii Jet solex(8) of orifice of 0.42 rmn in diameter.
Fig 2B:- Illustrates the sectional view of an Improved Cut off Valve sub assembly In distributor valve as p^- the invention whidi consists of Qioke(8) of orifice hole of 1.6 mm in diameter In distributive valve whidi governs the rate of air flow from downstream to upstream.
Fig 3 A:- illustrates the enlarged sectional view of the Cut off valve sub assembly In distributor valve in the existing art.

Fig 3 B :- illustrates the enlarged sectional view of the improved Cut off Valve sub assembly in distributor valve as per the invention.
Fig 3 C:- illustrates the sectionall view of guide sub-assembly of Cut off valve assembly as per the invention wherein the movable rubber diaphragm fixed in the said guide sub-assembly moves u or down according to the differential pressure.
FIG 4:- illustrates the enlarged sectional view of Cut off valve assembly as per the invention wherein the floating guide sub assembly with the diaphragm in distributor valve.




diaphragm(12) fixed on guide sub-assembly(13) due tD differentiai pressune across the diaphfagm(12).
If rate of charging into Ctontrol reservoir Is more^ the diaphragm(12) flexes tire guide sub-assembly(13) downwards piKhlng the valve(2) away fn>m Its seat When valve(2) is moved away from its seal; compressed air charges freely via the annular passage provided around the valve(2). The additional free flow of compressed air downstream condensates for the delay In the charging rate of Auxiliary reservoir and builds up Auxiliary reservoir pressure faster until the pr^sure in Auxiliary re^rvoir Is same as pri^sure in Control reservoir.
In case of iarg^^ time lag between charging level of Control reservoir and Auxiliary reservoir, due to higher differential across the diaphragm(12} fixed to floating ginde sub-a8sembty(i3), the latter- moves down to a greater depth forcing the valve(2) to lift off its seat by a greater distance. When this happens, the new spring(6) gets compres^^ nrwre arid consequently exerts a higher downward force on va{ve(3). Wf»n the downward force of new spring(6) reacts a level where it Is more ttian upward force of spring (7) under valve (3), the valve(3) Is also forced to nrtove away from its seat creatirH} an additional free passage for comprised air to flow In ttie annular space provided around tte valve{3). This additional quantity of air passes direcdy into Auxiliary reservoir through the unrestricted annular spaces anound the val^re(2) and valve(3).
This means the charging of two reservoir (Control &. Auxiliary) of dissimilar volumes (such as 6 iitr^ and 200 litres) are charged at the same tjme.
As per the invention, in a Cut off assembly of Distributive Valve for use in railways air braWng systems, the said choke has a hole of atieast of 1.6 mm diameter.
As per the invention, in a Cut off assembly of Distributive V^lve for use in railways air braking systems, wherein the rate (^ charging onto said Auxiliary Reservoir and rate of charging onto said Control reservoir nnovi^ the said dlaphragm(12) due to diflfenential pressure across the diaphragm(12).

As per the Invention, in a Cut off assembly of Distributive Valve for use In railways air braking systems, wherein when the rats of the charging onto said Control reservoir is greater, the said diaphragm(12) flexes the said guide sub-assembly(13) downwards, thereby pushing the said valve (2) away finom its seat; and allowing addltlonai compressed air freely via the annular passage provided around the valve (2), thus compensating for the delay in the charging rate of Auxiliary Reservoir and builds the Auxiliary Reservoir pre^ure faster until the pressure in Auxiliary Reservoir is equal to pressure in Control reservoir.
As per the Invention, in a Cut off assembly of Distributive Valve for use In railways air braking systems, wherein In case of larger time lag between charging level of Control reservoir and Auxiliary Reservoir, due to higher differential acrc^s the diaphragm(12) fixed to floating guide sub-assembly(13), the guide nrioves down to a greater depth forcing the valve(2) to lift off its seat by a greater distarce, thereby increasing the compre^ion further on the said spring (6), which in turn exerts higher downward force on valve (3).
As per the Invention, in a Cut off assembly of Distilbutive Valve for use in railways air braking systems, wherein in case of tinrie lag between charging level of Osntrol reservoir and Auxiliary reservoir, when downward force of spring (6) Is more than upward force of spring (7) under valve(3), the valve (3) Is forced to move away from its seat thus creating an additional free passage for comprsssed air to flow In the annular space provided around valve(3) alongwlth the free passage for compressed air to flow in the annular provided around valve (2).
As per the Invention, In a Cut off assembly of Distributive VSalve for use in railways air braldr^ systenw, wheriein the rate of flow of air tiirxjugh the said hole in the said choke(8) is in reverse from the Qjntrol reservoir in case of slow drop of pressure m the brake pipe due to normal leakage same as rate of leakage.
As per the invention, in a Cut off assembly of Distributive Valve for use In railways air braking systerrs, wherein the size of said choke(8) is such that the

charging time of Auxiliary and Control reservoir is maintained to be approximately the same.
As per the Invention, in a Cut of assembly of Distributive Valve for use In railways air braking systems, when brake is applied by driver the compressed air pressure in the brake pipe is reduced, there is a sudden drop of pressure under the diaphragm(12) (of floating guide sub-assembly(13)} causing it to flex downwards simultaneously isolating the Control reservoir. The drop of pressure only in brake pipe while holding the pressure in Control neservoir unchanged, will cause the Distributive Valve to apply an air brake on the particular vehicle in which it is fixed.
In this invention the principle advantages have been attempted to achieve are ;-
1, Elimination of problem related components JET SOLEX wNch was causing
the field failures. Z The failure due to dust proof operating condition Is overcome in this
version. Instead of a fine orifice of 0.42 mm the new design has been
aimed at further enlarging the orifice sl2s to 1.6 mm so that the dust can
never get trapped in the passage.
3. Interchangeablllty of "Modified Cut off Valve" sub-assembly Into the distributor valve type C3W is possible on the basis df retorfitment
4. RedudSon in the number of field defective and hence consequently will enhance the quality rating of distributor valve.
5. Overall performance of the valve Is totally unaffected and conform to stipulated standards in practice.
Prototype as per the design modification were made and fixed in the valves to judge the perfomance. The resists were in acordance with the stipulated standards.
A few more samples were made using the regular production methods and a large batch of modified valve tested. Even In these cases performane» Is observed to be as per the stipulated stardards.



1. A Cut off assembly of Distributive Valve for use in railways air braking
systems including :
a stopper piug(l),
a guide sub-assembly(13) forcommunicating with the compressed air from brake pipe and fixed above the stopper plug(1),
a movable rubber diaphragm(12} fixed in the said guide sub-8ssembly(13},
a va(ve(2) communicating with Control reservoir vide the said guide sub-assembly(13) and also having annular passages around the valve(2) so as to communicate downstream onto Auxiliary Reservoir,
a valve (3) positioned away from valve (2) with space In-between, communicating with Control reservoir via valve (2) and also having annular passages around the valve so as to communicate downstresam onto Auxillary Reservoir,
a choke (8) having a central hole within which compressed air from brake pipes enters a Distributive Valve ,
a spring (6) exerting a downward force on valve (3),
a spring (7) exerting a upward force on valve (3),
a spring seat (4) supporting the spring (7),and
a cirdip (5) to hold the components.
2. A Cut off assembly of Distributive Valve for use in railways air braking systems as claimed in dalm 1, wherein said choke has a hole of atieast of 1.6 mm diameter.
3. A Cut off assembly of Distributive Valve for use in railways air braking systems as claimed in dalm 1, wherein the rate of charging onto said Auxiliary Reservoir and rate of charging onto said Control reservoir moves the said dlaphragm(12) due to differential pressure across the dlaphragm(12).



7. A Cut Off assembly of Distributive vaive for use m railways air Drawing
systems as claimed in claim 1, wherein the charging time of Control and Auxiliary
reservoir Is maintained equal in irrespective of size of the reservoirs.
8. A Cut off assembly of Distributor Valve for use in railways air braking
systems as claimed In claim 1, wherein when the compressed air pressure In the
brake pipe is reduced by a brake vaive by driver, the sudden drop of pressure
under the said diaphragm of said cylinder sub-assembly causes the diaphragm to
flex downwards simultaneously thus isolating the Control reservoir, holding the
pressure away from the motor brake pipe and causing the distributor to apply the
brake.


Documents:

1391-mas-1997 abstract duplicate.pdf

1391-mas-1997 abstract.pdf

1391-mas-1997 claims duplicate.pdf

1391-mas-1997 claims.pdf

1391-mas-1997 correspondence others.pdf

1391-mas-1997 correspondence po.pdf

1391-mas-1997 description (complete) duplicate.pdf

1391-mas-1997 description (complete).pdf

1391-mas-1997 drawings.pdf

1391-mas-1997 form-1.pdf

1391-mas-1997 form-13.pdf

1391-mas-1997 form-19.pdf

1391-mas-1997 form-26.pdf

1391-mas-1997 form-29.pdf


Patent Number 198053
Indian Patent Application Number 1391/MAS/1997
PG Journal Number 27/2006
Publication Date 07-Jul-2006
Grant Date 21-Mar-2006
Date of Filing 25-Jun-1997
Name of Patentee RAILWAY PRODUCTS(INDIA)LIMITED
Applicant Address HARITA-HOSUR 635 109
Inventors:
# Inventor's Name Inventor's Address
1 TV SIVAPRASAD, HARITA-HOSUR 635 109
PCT International Classification Number B60T13/122
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA