THREE STAGE GAS PRESSURE REGULATOR

REGULATEUR DE PRESSION DE GAZ A TROIS ETAGES

English Abstract

The present invention provides a supplementary pressure regulator that can be
used with conventional single or multi-stage pressure regulators. It may also
conveniently be used with a novel two-stage balanced pressure regulator to
form a three-stage vacuum demand pressure regulation system which may be used
to regulate the pressure of compressed gases used as fuel in engines, such as
natural gas used in natural gas powered vehicles. The pressure regulator of
the present invention is a robust, compact, high flow, low droop, low pressure
drop, low set-point drift and low creep regulator which is suitable for both
OEM and after market use. It is particularly useful in mono-, bi-, and dual
fuel engine applications.

French Abstract

Cette invention concerne un régulateur de pression complémentaire pouvant être employé avec un régulateur de pression traditionnel à un ou plusieurs étages. Ce régulateur de pression complémentaire peut également être combiné à un nouveau régulateur à deux étages d'équilibrage des pressions de manière à former un système de régulation de pression à vide à trois étages; ce système de régulation peut être employé pour contrôler la pression des gaz comprimés utilisés comme combustibles dans les moteurs, tel que le gaz naturel pour les véhicules marchant au gaz. Ce régulateur de pression est robuste, compact et possède un fort débit. Le taux d'incertitude quant à la pression de sortie ("droop") et les risques de chute de pression sont faibles. Toutes ces qualités, ajoutées à une faible dérive de la valeur de consigne et à un faible risque de hausse de pression dans le régulateur ("creep"), en font un appareil adapté au marché d'équipements d'origine ainsi qu'au marché secondaire. Ce régulateur convient particulièrement à des applications sur des moteurs utilisant un ou deux carburants, que ce soit séparément ou en mode mixte.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A pressure regulator comprising

a housing comprised of a first housing member (1102) and a second
housing member (1104);
a diaphragm (1680) disposed within said housing between said first and
second housing members, said diaphragm and said first housing
member defining a first chamber within said housing, and said diaphragm
and said second housing member defining a second chamber within said
housing;
wherein said pressure regulator further comprises
a lever assembly (1630), pivotally mounted on said first housing
member, said lever assembly comprising a lever arm (1632) having first
and second ends, the first end of said lever arm being hingedly
connected to said diaphragm;
valve means located in said first housing member for regulating the flow
of fluid into said housing, said valve means comprising a pintle assembly
(1600) pivotally mounted on said lever and being disposed within an
aperture (1426) in said first housing member; and
spring means (1442) mounted on said first housing member engaging
the second end of said lever arm and acting to urge said valve means
into an open position.
2. A pressure regulator according to claim 1, adapted to regulate and control
the
flow of pressurized fluid to an engine, wherein:
said first housing member has an inlet port (1120) adapted to
communicate with a source of high pressure fluid, and said second
housing member has a reference port (1140) adapted to communicate
with a source of reference pressure;
and wherein said valve means further comprises a valve seat (1410)
adapted to cooperate with said pintle assembly to interrupt the flow of
fluid from said inlet port to said first chamber when the flow of fluid to
said engine is not required.

3. The pressure regulator of claim 1, wherein said first chamber and said
second
chamber are of substantially the same volume.

4. The pressure regulator of claim 5, wherein said inlet port and said outlet
port are
substantially the same size.

5. The pressure regulator of claim 1, wherein said valve means further
includes
means adapted to retain said pintle assembly in a closed position.

Description

WO 96117280 PCItCA95tO0667
- 0 21 99 5 21

THREF S~AGE~ GAS ~'K SSURE REGULATOR
TE~INICAL F~E~ D:
The present invenUon relates to a novel pressure regulator which is particulariy
5 useful as part of a vacuum demand pressure regulation system used to control and
regulate the pressure of c~ u,essed natural gas or propane in eny;.,es fuelled with
these fuels. It may be used as a supplementary pressure reg~ tor with conventional
single or mulU-stage pressure reg~lators or as the third stage of a novel, three-stage
pressure reg~l~tor.
Io BACKGROUND ART:
It is becu",i"g illuieasi~lyl~r co"""on to use so-called ~lle",dle fuels such as
propane or natural gas in intemal combustion enyi"es. Vehicles which are
manufactured to operate on a primary fuel such as gasol;.,e may be converted to
operate on one of two or more alte",dLè sources of fuel such as p,upane or natural
IS gas. In some such conversions the ope,al~r has the abiiity to switch belY:~rn fuel
sourcss depenLli"~ on the avdila~i~i;y and price of these fuels.
Wllile the vehicles which are converted to run on these alte",dle fuels have in
most cases been manufactured with storage tanks for gasoline pumps for moving the
gasoline from the tank to the engine and carburettors or fuel i,.jer~ for introducing
2~ the fuel and the required amount of air for combustion mto the engine it is gerleldll~
ne-e.ss ..y to add to the vehicle being converted the co",ponenls required to store the
altemate fuel, and to move it in the required qud"lilies and at the desired pressure to
the engine of the vehicle.
G~ceous fuels such as p~u~ane and natural gas useful as alte~lldlè fuels are
25 gene,dlly stored in pressurized cylinders in which the gas is colllplessed into a
l-,anageable volume. Ir,~c:dsi,,~ the pressure to the highest level that can safely be

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~ 2 ~


hdndled by a pressurized storage cyiinder i.,~;r~ases the amount of fuel that can be
stored in that cylinder, and exl~nds the ~ la"ce that the vehicie can be driven before
refuelling. Typical storage cylinder pressures range from 2Q00 to 5000 Ibs./in.2. While
the pressure within the storage cylinder in most cases provides the force necess~qry to
5 move the fuel to the engine, intemal combustion e"y;.,es cannot operate at the high
pressures typically found in the storage cyiinder. The pressure of the gas must be
reduced to a levei at which the engine can be operdled safely, and ",ai.,ld;.,ed at a
reiatively co"alant reduced pressure to ensure efflcient ope,~lion of the engine. In
addiLion, it is often desired to provide a vacuum demdlld fuel system for such vehicles,
o in which the fuel is introduced to the engine at subslan~ic.''y the same pressure as the
combustion air. In such a system, the fuel is not forced into the engine by a pump or by
pressure, but is drawn into the engine by a reduction in the pressure of the combustion
air as that air is drawn into the engine. In such a system it is illl~oll~"l to ensure that
the relative pressures of the air and fuel remain consta"l to ensure proper air and fuel
ratio in the engine.
Consequently, the fuel pressure must be regulated as it is reduced to ",ini",i~t:
the effect of those factors-that affect the output pressure from the pressure reg~'qPtion
system, and h ensure that the pressure of the fuel el llel in~3 the engine is consta"t even
as the pressure in the storage cylinder is reduce-~ At the same time, the pressure
20 reg~qtion must permit as much fuel as possible to be removed from the storage
cylinder, and thus must permit the pressure in the storage cylinder to fall as close to the
engine operc.li,,g pressure as possible, whiie still providing the force required to move
the gaseous fuel through the pressure re~ on system and into the engine.


~ WO96117280 0 2 1 9 9 5 2 1 PCTICA95100667

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Conver,tiorlal pressure regu~ators having one or more stages over which the
pressure of the reguiated gas is reduced are well-known and have long been used to
reduce the pressure and regulate the flow of c~ .,essed gases. Some of these
conve"liona! pressure regulators are known as pressure-balancPd regulators. These
typically use various d"dn~e,llenl~ of springs, ~J;aphndyllls and n~achi.,ed parts to
baiancP pressures and fluid flow over the various stages of the regu~ator.
For e~cll"p'~, U.S. Patent No. 2,794,321 issued June 4, 1957 to F.J. Wamer et
al d;sclQses a single stage fuei pressure regu~tor said to be useful in reducing and
regulating the pressure of fuels such as propane for use as fuel in an intemal
lo combustion engine.
Some pressure regulators, such as those cGIlllllGnly used on tanks of
compressed gas such as oxygen or acetylene, are desiy"ed to permit the operator to
adjust the pressure drop across each stage. Others, such as those typically used in fuel
supply systems, are pre-set and permit either no adjustment, or only ~fine tuning", of the
output pressure by the operator, although more e~LenSiVe adjusllllenl~ by aull,o,i,e.l
servics per~or,nel can be made.
The pressure reg~ t~rs of the prior art suffer from a number of disadvallldges
that the supplementary pressure reg~ tor of the present invention is i"lended toovercome.
One of the p,i".,ipal problems assGcialed with pressure reg~ rs of the prior artis referred to as ~droop7, i.e., the degree of u"c~,lai,)ly about the output pressure of the
reg~' tnr. This degree of uncertainty is a function of the fuel flow rate and the pressure
in the storage cylinder. "Droop~ may create problems in the proper opel.l~iGn of an
engine bec~use, for exanl, '~, the fuel injectors co""nonly used on modem vehicles are

W 0 96/17280 0 2 1 9 9 5 2 1 PC~rtCA95/00667

--4-

i-,tencled to operate at a c0l3~1dlll fuel pressure, and the typical carburetion venturi
mixer requires the pressure of the fuel to match the pressure of the air to ensure proper
fuel-air mixture control. Previously proposed solutions to these problems involve the use
of te""~er~lure and pressure sendei~ to detect va.ialions in the fuel lt:"~pe~dlure and
5 pressure and make app,opridLe adju~l."enl-~ to the oper~lion of the engine. The
present invention is intended to overcome or reduce the problem of droopn without
requiring adju~l",enls to the ope,alion of the engine.
Another proble", is Icreep~ the i-,~ ase in pressure within the regulator and
doJ~ l-ed--~ from the regul~tor, when the injector is tumed off or the shut-off solenoid is
~o closed for carburetted engines, i.e. the fuel supply to the engine is inlended to be shut
off. This is sometimes rere~ to as zero-flow rate pressure rise and is caused by
i"~pe"e-t sealing of the reg~lator components incJuding the fuel shut-off so'onoid.
Whiie creep may be reducsd by i-~ asi,~ the sealing forces within the reg~ tor such
an i."_rease often requires modi~c~iions to the structure of the regul-ltor not only to
15 apply these higher forces but also to babnce them, to ensure that the regu~^tor can be
opened easily when the supply of fuel to the engine is to be re~ld. led.
~ Csor ~led with this zero-flow-rate pressure rise is leakaye of fuel from the
reg~ tor to the dl".o:,pl~e.e.
Another pluLle.-~ with reg--'atnrs of the prior art is set-point drift namely the
2~ degree of u..ce.ldi,.ly about and vdlidliol) in the output pressure of the reg-~l tor due to
~J.anges in operdli,-~ te",~erdl.lre or engine fuel or airflow requi.~l..e"l~. Set-point drift
may create problems in the proper operdlion of the engine as, for exdmpe the
carburetion venturi mixer requires the pressure of the fuel to match the pressure of the
air to ensure proper fuel-air mixture control.


WO96/1'7280 0 2 1 9 9 5 2 1 PCI'ICA95/00667

5 --


The flow of fuel from a storage cylinder to a pressure regulator is typically
co~ "ed ~y a so'2n~i cor,l,olled valve that may be mounted on the regl~lqtor itself,
and that may be opened by the ope-dlor of the Yehicle just before the engine's ignition
system is switched on. The solen~-~ con~"ed valve typically opens against the storage
5 cylinder pressure and, as it opens, fuel flows through the resu~at~r to the engine. In
regul~tor asselntl-os of the prior art, it may take several 5ec~nds for full fuel flow to be
available for the engine's fuel injector, and for the desired operdli.,g pressure to be
reached at the fuel injector. Uniess the operalor of the vehicle waits for this interval
before s~;'cl,;,l~ on the ignition, the vehicle may not start properly, or may not start at
o all.
In the spring~Jiaphldylll based reg~ tors of the prior art, the output pressure is
a function of a large number of validb'~s inciuding the input pressure to the reglllator,
the output flow rate, the chalcl~;tt,li~lics and plope.lies of the diapl,,dylll~ inciuding its
area and stretch, the ,e~,ence pressure, the orifice area and shape, the pintle area and
5 shape, the spring rate, and the oper~lill-J le,llpeldllJre. Changes in these vd.iables
result in fluctll~tions in the output pressure, and rPquire the output pressure of such
regulators to be set at a level higher than the optimum level to ensure that there is at all
times a positive fuel flow to the engine. This may resuit in opeldli-lg i-,~ "enc.es and
higher than necPss~-y emission levels. In ad ii;ion, whiie the reg~'Ator may be set to
20 provide optimum idling condilio,)s, the effect of these variables may cause delays in the
retum of the regulator to those optimum co.~ditions after e~tlellded high speed
operalio.), typically leading to stalling of the engine.
Conve.,lional vacuum demalld pressure reg~lation s~ ,-,s are e~ "~ely
sensitive to changes in the rerere"c~ pressure, particularly under idle condilio.ls. Minor


WO96/17280 0 2 1 9 9 5 2 1 PCI/CA9~/00667


varidlions in the rt rerence pressure, unless responded to quickly, can cause an error in
the refert:nce pressure at the regu~tor with respect to air inlet pressure to the engine.
This ,ererence pressure error can cause the carburetion venturi mixer to react poorly
due to a ",is",alch in the pressure of the air and fuel. It can also lead to fuel supply
s shut-off to the engine and possiL'~ engine stalling.
Thus, it is an object of the plesenl invention to provide an improved pressure
regul~tor which is adapted to provide fast response and maximum sensitivity to
changes in the inlet pressure, and which Ir,i"i,r,i~es fluctu~tions in the outlet pressure.
It is also an object of the pr~senl invention to provide an improved pressure
0 reg~ tor adapted to open quickly even against high storage cylinder pressures, thus
allowing the regulator to reach operating pressures almost immediately.
Another object of the preser,l invention is to provide a pressure regulation
system that Illilli.,,i~es the cylinder pressure necess~ry for err,cienl operdlion of the fuel
pressure supply system, and thus pe""iLli"g longer ope,dlion of the vehicle before
5 refuelling.
DISCEOSURE OF THE INVENTION:
The p,eseril invention provides a s~Fle "entary pressure regu'ator that can be
used with conver,lional single or multi-stage pressure re~ tnrs. It may also
conveniEr,lly be used with a novel two stage balanced pressure regulator to form a
20 three-stage vacuum demand pressure regulation system which may be used to regulate
the pressure of compressed gases used as fuel in engines, such as natural gas used in
natural gas powered vehicles. The pressure regulator of the present invention is a
robust, compact, high flow, low droop, low pressure drop, low set-point drift and low


W096/17280 0 2 1 9 9 5 2 1 PCI~/CA95tO()6G7

7 --

creep regulator which is suitable for both OEM and after market use. It is particula
useful in mono-, bi- and dual fuel engine applications.
The improved su~!e.~e~la~y pressure regulator of the present inventi~
S the effect of several of the factors that affect the stability of the outp
pressure of the regulator by providing opli",i~ecl balancing of several of the co~"ponen
of the regulator. The pintle assembly of the s~ !en,~nld~y pressure of the prese
invention is balanced to eli--,i"ate the effect of input pressure which is one of the mc
si~lliricanl contributors to overall droop. The use of a balanced regulator in the prese
invention allows a much smaller regulator to achieve the desired droop level. Small
regulators generally have faster response and are in general cheaper to make th;
larger regulators pelru""i"g the same function.
The supplementary pressure regulator of the present invention provides ftr
transient response to fluctu~tions in the inlet pressure.
The su~,F'en~enlaly pressure regulator of the ,ul~sent ir~vention comp,i~.es
suL~.lanlially hollow body having a sul.:jta"llally pressure-tight dia~ h,ay,-, dispos~
therein. The body is conv~n.e.,lly co,-"l~,i5ed of two body members having wh
asselu~ ~ abutting edges which may be r.1stened logell,er by any conventior
means to form the regulator body. The .liapl)r~y", may conveo-erlly be It:tai"ed
place beh~_r.) the abutting edges of the two body me",l~e-~. The ratio of the surfa
area of the .3;a~cl,,dylll to the interior volume of the regulator is suL,slanlidlly higher th
co,.""only found in pressure regulators of the prior art. One side of the diaphraylll
e~,uosed by means of a rerer~:nce port to a yener~lly co~lanl ,~ference pressure U
may be al",ospl,erio pressure or which in the case of turbo-chalyed engines may
the pressure existing at the point that the air and fuel are mixed The other side of 1


WO 96/17280 0 2 1 9 9 5 2 1 PCT/G~95/OOGC7

8 --

diaphlay"l is exposed by means of a fuel inlet port to a flow of gas at a regulated
pressure that is intended to be relath/ely consta,ll with respect to the ,ererence pressure
and in the case of the prefer,~d el"bodilll6nl is i~ended to be substalllially equal to
that ~ r~nce pressure.
Mounted on the regulator body are shut-off sa' .~o ~ means to open and close
the ~low of pressurized gas from the reglllator inlet to the regulator body, and cranking
and idling sc'sncid means to permit the flow of fuel from the regulator inlet to the engine
during starting and idling colldiliolls. A pressure regulating pintie asser"bly is IJ;~posed
between the gas inlet to the regulator and the regulator body to control the flow of gas
lo through the regl'~-tor, and is connecled to the Jiaphray". to form a pressure regulating
assembly within the regulator body.
The shut-off solenoid means may be inleg,dlly constructed with the pressure
regulating pintle assembly to ensure co""~l6te closing of the regl~lntor when the
regulated fuel supply is shut off and to provide a c~"",a~;t and space-etric;~nl
15 asse,nbly.
The pressure-regulated side of the d;api-"~yl,l is in fluid commu";calioll with the
engine to which the pressure regu~-ted fuel is d;,e~.ted. While the engine is ope.~ti"g,
the fuel inlet to the engine is gen6r~11y at a pressure lower than the regulnted pressure
within the body of the regulator, due to the movement of combustion air to the engine
20 past this fuei inlet.
In a pn:r~r,e~ embodiment of the pr~senl invention the l~f~ ce pressure is
the pressure of the air supply source ~which may be at",oçph~,ic or turbo-ch~r~ecl) and
the fuel pressure at the regulator outlet is i"lended to be sul,~tal,lially equal to that
rer~rellce pressure. In the opeldlion of the engine, combustion air is either drawn or


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~ ~ 02199521
wo 96/17280 Pcr~C~s~/oo667

g

forced into the engine and the flow of air through an inlet venturi results in a lower
pressure at the venturi throat that causes the pressure-regulated gas to flow from the
regulator into the engine.
The diaphragm is rei~ruroP-J by at least one baukilly plate centrally mounted onone side of the cliaphrdylll~ p~e~elably the regulated side. The bacl~i"y plate is pivotally
connected to the pintle valve asse~,lbly which regulates the flow of gas through a pintle
orifice into the chd",l)er of the regulator. As the regulated pressure varies from the
r~ferdrice pressure the Jid~)hldylll moves to the lower pressure side of the regulator.
This movement causes the pintle valve asse,nbly to move within the pintle orifice and
c:hariyes the size of that orifice and the rate at which the pressurized gas flows into the
regulated side of the regulator body. This chanse in flow rate ,~ jlor~s the pressure
baiance within the regulator body. A second baoki,lg plate may be provided on the
rer~rt:nce pressure side of the Jiaph~ylll. The shape of the pintle and of the pintle
orifice may be chanyt:ci to provide for the most er~; n( flow of pressurized gas around
the pintle asser"bly and through the pintle orifice.
While one or two bacl~ plates are used to r~i~lrurce the centre area of the
Jiaph-dy"~ and to provide a means for conne~:li"y the d;3ph,ay"~ to the pintle ass~r"bly
it will be t~"Jer~tood that the baclci"y plates must be surri~ ;anlly smaller in ~lid",eler than
the Jiapl"dy"l to permit proper movement of the Jia~l)ldylll within the regulator body.
Several of the cor"por,ents of the St~ el ltdl y regulator of the preseril
invention have novel desiy"s which permit the regul~or to ach ~vc the objects of the
invention.
The novel pintle assei"bly of the p,~senl invention utilizes an all-metal pintle in
its ~l~fell~d el,.bo.li",ent to ",i"; ~ e fluctu~tions in and drift of the regulator set point

WO96/17280 0 2 1 9 9 5 2 1 Pcrlc~g~/onGfi7


i.e., the p~edele"";"ed output pressure, due to vdlidlion~ in operali"g tel~peralures and
engine fuel and engine air flow rates. In addilion, it incor,uordles an integral solenoid to
seal the pintle orifice dunng zero flow cond;tior,s.
The pintle asse",bly may be connec~ed to the dia~,h,~ylll by means of a
5 lightweight die cast or plastic lever, thus providing a relatively high pintle-to-diaph,ay"l
force ratio, which in the case of the p,~fer,~d el"bolJ~imerit may be in the range of about
6:1. The lever may be connected to the pintle by a suitable pivot means, such as a
spring loaded slip joint. The pintle asselllbly may be conne~;ted to the diapl"~.Jm via a
bloch~ of low friction, low mass r"aterial such as Zytel, which allows relatively easy
lo lateral movement of the d;apl,,dylll with respect to the lever.
The diapi,rdy", backing plates may convt:n'~nlly be formed of aluminium
stampings and thus can be suL~lal,Udlly thinner than those used for regulators of the
prior art.
The ability to use a relatively thin bachiuy plate is ach:~ed through the use of a
Jiaphl~g", stop ring on the interior side of the regulator body, and by incorporating
suitable pivot means such as a spring loaded slip joint between the pintle stem and the
pintle pin. The stop ring conldcl~ the ba-,hing plate and supports the regulator
diaphldg", in its most extreme, or full strike, positiori, which g~nerdlly occurs when the
engine is being fuelled with the primary fuel source, such as gasoli"e. In that situation,
20 there is a full venturi vacuum applied to the dialJhldylll~ but no fuel flowing into the
regulator body to replace the air removed by the vacuum. The dial h~dg~l and backing
plate move to the regulated side of the regulator and contact the stop ring which limits
the displacemeril of the diaphragm while only minimally reducing the volume of the
regulator body.


WO96/17280 0 2 1 99 5 21 PCrlC~9~;lOO~fi7

- 1 1 -

In the case of over,u,essure in the regulator, which may occur in the event of an
engine bach~i,e or upon rapid closing of the throttle, the spring loaded slip joint between
the pintle stem and pivot allows the ~ia,ol,r~y", to bottom out against the lower cover,
thereby siyniricantly reducing the .~il,er,gtl, requirement of the diaph,ay"l lever and
ba.;hi"g plates.
The diapllrag", cavity and cover plate may be des;~ ed to embody an
apprvp,iale safety factor over the. normal op~r~li"g pressure within the regulator which
is typically about 2~ psig.
The supple",enta,l/ pressure regulator of the pr~senl invention provides a shut-lo off solenoid assembly, inciuding a SOIel15i~' piston, which is an integral part of the third-
stage pintle arrangement. The s~lenc.d piston provides a guide for the pintle when it is
in the open position and seals the pintle orifice against the flow of gas when it is in the
closed pos;tion. This novel ~"anyel~)ent permits the use of a lower amp-turn coil, as
explained below, as the pintle return spring provides an o~,po ,;-,9 force to the pressure
15 force which is applied to the sc'en~ ~' piston seal.
The so'~ ns ~ piston is so a"dnged that, when the so'ena. ' is energized and thesolenoid piston is open, it applles no force to the pintle, which is ~,5;.~lained in a
bala"ced pos;lio" by the oppO5;~1y forces of the gas pressure and the regulator springs
of the pintle asse",bly.
When the solenoid is de-eneryi~ed, the force of the springs forces the solenoid
down against the pintle, forcing it to contact the orifice, and thus ~lu~up:. 19 the flow of the
fuel through the pintle orifice. Once the sol~r.c'~; seals off the pintle orifice, the pressure
which acts on the pintle in the open po5ilio n is gone, and the regulator spring provides a

wo 961172~0 0 2 1 9 9 5 2 1 Pcrtc~ss/~oGG7


- 12 -


force, against the sole.lcid closing force, and in the opening ~ ;tiol) of the solenoid,
thereby reducing the magnetic force required to open the sole ~~ i
In some ~r~plioAtiol)s of the pressure regulator, a shut-off sc'EnoirJ assembly
may not be required, and a plug may be used to close the pintle cavity and provide
5 support for the pintle.
The supplementary pressure regulator of the present invention may incG.~or~te
an adjustable orifice, someti"~es rerened to as a power valve, to regulate the flow of
fuel through the regulator outlet~ The power valve may conveniently utilize a threaded
shaft by means of which a valve disc may be moved up and down either manually or by
lo means of a suitably powered motor, within the power valve to adjust the size of the
regulator outlet.
The suppiementary pressure regulator of the present invention may also
inco,l.or~le an idle solen~.~' asser"bly and a cl~"hiny sclenc.d asseu.bly, each of which
may be supplied with fuel directly from the inlet of the s~!~F'~.~"~nla.~ regulator of the
Is ,olese,)l invention by means of a drilling or other aperture from the pintle cavity. Each of
the idle so' nc ~ and cranking s~' n~.~' asser. '~"es may contain sul,slantislly the same
so'e.~ ~' . Both the cranking and idle orifices may be l"acl.;,.ed into the regulator body
to minimize the cost of production. In ad-~iliol" both sc'e~ . cavities are desi!J,.ed for
the ider.lical sr,'e:~o ~ core tube that is used in all ss'en~ tions throughout the
- 20 regulator. This core tube c0~5ist:; of a ..lay,letic flange and stop, and a non-magnetic
sleeve. All three parts, i.e. stop, flange and sleeve, are brazed togetl,er to provide a
suL.~t~lllially gas tight seal ç~p~hle of ~.itl)ctalldi.,g at least about four times the
maximum operating pressure norrnally found in the regulator under norrnal service
c~ iti~


021 99 521
WO 96/17280 PCIICA95100667

- 1 3 -

In some e",bodi",enb of the invention it may not be necess~-y to use an idle
solenoid or a cranking sol~noid or either of them. When either or both of them are not
required the orifice may be sealed with a s~-it.~- 'e plug thus pellllillilly use of a
slal ,dar~liLed regu~tor body for a variety of al-plicz lions~
s While the improved supplementary pressure regulator of the present invention
may be used in associdlion with conve"lional single or multi-stage pressure regl~ators,
it may be most effectively used with the novel two-stage pressure regu'~tor di~closed in
co-pending patent -~F ~3tion No. 2131,108.
The novel two-stage regul~tor d;3closed in that ?~F'i~tion provides first and
o second stages desiy"ed to ",i";."i~e the mass of the dynamic cor"~.o"enl~ to provide
faster response to changes in operating cGnditions in the regulator. Each of the two
stages utilises two counter wound springs to ",in;."ise the spring cor,:,lant and the
height of the spring tower required. All of the dynamic first stage co,~,~oner,l~ with the
eAceplion of the pintle may be constructed of aluminium, or other liglll~ oalerials
IS having a~.pr~p,iala sl.el,ytl, and ll,el"~al conductivity prope,lies.
A rolling did~hr.~ym is used in each of the first and second stages to ma;"l..i" a
cor,al~.,l effective area throughout the entire range of movement of the diaphra53,...
Such a d;a~lt(ay". has greater durability, and allows higher manu~acturing tolerdl,ce
than a flat d;aphf~y"" and to a large extent elin-;i)dtes the hysler~ effect of flat
20 diaph.dy.ns. A diapl,laylll of this configuration has an ~Ycepliol1dlly long oper~lil,y life,
and good cold weather pe,r~-r-,-al-ce and durability.
In that reg~ tor, the first stage spring tower is sealed from the envi,on",ent and
,er~,ei1ced to the pressure in the second stage.


1 ~ 02199521
wo 96117280 pcrlcA9~lon6G7


- 14 -


Each of the first and second stages includes a novel pintle asse~,bly desiy"ed
to eli",indle polerllial leak paths.
The construction of each of the first and second stages of that particular
regulator are sul,~ ,lially idenlical, with the ~;ce~liun of the ar,d,-yer"er,t of the
5 particular pintle seal used, and the details o~ the spring tower construction. A captured
O-ring may be used for the second stage pintle seal since that seal is ex,uosed to a
maximum pressure of only about 170 psig. The second stage spring tower may contain
a pressure adjustment screw which perrnits the adjustment of the pressure in the
second stage and thus the output pressure from the first two stages of that reg~ 'or.
The pressure regulator of the atù~el,lenlio"ed co-pen~li"g at~plicalio" may be
provided with a pressure relief valve which is intended to operale in the event of a
failure of the first regulator stage. The pressure relief valve (~PR\/ ) is provided between
the first and second stages and consi~s of a low mass piston, a PRV spring an~ a PRV
tower. Once a pre-dete"";"ed pressure in the PRV is ,~a~;l,ed and the piston is
displaced and forced wide open, providing i",l"e-l;ale pressure relief.
The two-stage regul?tor provides le",perdlure controlling fluid passayeways to
control the temperature of the regulated gas and to co",~ensale for the heat loss as the
gas e~ "ds. The supp'e nenla~y regulator of the p,~senl invenUon provides
con,,ue,,sdliu,, ~o! fluctuating gas ter"peralures through the use of the oplior,al power
20 valve.
The two-stage pressure regulator di;.closecl in the atur~r,,enlioned co-pending
arplio~liùn requires only minor l),odi~icdlions to be used with the surr e."enlary
pressure regulator of the pr~sent invention and is the basis of the three-stage regulator
design. The regulator body requires some minor machining ~"o~lifi. alions. The most


WO96/17280 () 2 1 9 9 5 2 1 PCT/C~951006C7

- 1 5 -

s;y"iricanl moJirication is that the outlet pass~ge is left undrilled and a new outlet and
O-ring face seal gland is added to the left face. In addition the original mounting screw
localio"s on the left face are no longer used; instead mounting th~:ads are added
a~jacent to the face seal gland. Provision for an oplional coolant solenoid may be
added to the back face; this requires one addilional drill and plug in an appro~.,iale
localion in the regulator body. The first and second stage springs may be replaced with
lower force springs in order to produce the required first and second stage pressure of
60-170 psig and 23-26 psig, I~:spec;tively, for use in ~ssori ~l;on with the sul,,.le "er,ta,y
pressure regulator of the pr~s~nl invention.
o The suppler"euld,y pressure regulator o~ the presenl invention when used with
the two stage regulator provides a three-stage regulator that is much more compact
than regulators of the prior art.
In operation the pressurized gas which may be stored at a pressure of 150 psig
up to 5000 psig passes through a pn.l;..,;l,a~y pressure regulation system which may
15 be that ~ osqd in the arurel,le,-lionecl patent applicalic,n. The pressure of the gas is
reduced to a regulated pressure within a relatively narrow range, which may typically be
about 21 to 28, or more ~,eterdbly 23-26 psig (or such other pressure as might be
chosen and l~,ai.,l~i.,ed by appro~ri~le spring rate 5~1e~,tiûll5).
The natural gas or other fuel flows at this reduced pressure into the passa~GJ~
20 conl16~ y the pressure regulator of the p~s~nl invention and provided the shut-off
solg.lC cl iS open, may flow from there through the pintle orifice to the interior of the
regulator body. If the shut-off solenc-i is closed, it may flow through the cranking
supply passag~ray to the .;ra,1hi"y and idle solenoid ass6" ~blies. The interface
betw~en the - I~I;.lli,l~ry pressure regulation systen1 and the pressure regulator of the


021 99 521
wo 961172~0 Pcrlc~ssloo667


- 16


,,eser,l invention may be des;y"ed to ensure the most er~iu;_r,l movement of gas
between the two regulators.
Under normal operdli-,g cor,dilio"s as the gas starts to flow the sc!e ,~-~ opens
and permits the pintle asse,~,bly to move opening the pintle orifice. To ensure rapid
s oye";.,~ of the pintle, means may be provided to permit the gas to flow directly to the
regulator body to assist in the open;.~ of the pintle by balan~ y the pressure on either
side of the pintle and to provide a positive pressurized fuel flow to the engine.
Under cranking and idling col-ditiol~s fuel flow to the engine is low and sudden
vdridlions or puladlions in the ,e~r~nce pressure may cause a lei-,pordly closure of the
o pintle orifice. Accordingly optional separate cranking and idling assemblies are
provided to accor"",odate those circ-""slances. The C;ldll~ J assembly includes an
electrically cont,-)lled solenoid to that opens to permit fuel to flow directly to the engine
on start-up. The sc'eno.- may be cor,ll.'led ele~t,u,l~ y to puise the cranking
solEn. i~ at the rate needed to deliver fuel at the re~uired rate, such that the output
s pressure from the regulator is maintained at suLst~r,lially the same pressure as the
,efer~nce pressure. As the c,dnl~i"~ sc'-nc ~ receives the fuel from the inlet of the
surF!en~enld,y pressure regulator, its output is not affected by cl)d,)ges occurring at
start-up in the supplementary pressure regulator.
To ensure proper supply of the fuel to the engine in all operdlina~ corldi~ions and
20 regardless of the nature of the first pressure re~ ator the pressure regulator of the
p,eseril invention may be d"dnyed to provide a positive idle fuel flow to the engine to
ensure proper operdlion of the engine under idling conditiolls.
The idle circuit uses a scle. oid assel"bly to provide means to provide a ensure
a consldlll ",eGhan;cally adjustable positive fuel flow to the engine under idle

~I WQ96/17280 0 2 1 9 9 5 2 1 PCTICA9~/0~667
-
- 17--


conditior,s. As this circuit is also sourced from the second stage pressure, its output is
also immune to i"slanlaneous dist~"t.ancss in the third stage output or le~e,ence
pressures.
BRIEF DESCRIPTION OF THE DRAWINGS:
5 Figure 1 is a top, partiaily sectional view of the body of the pressure regulator of the
presenl invention, shown in its p,~r~n~d emiJodi",e"l as the third stage of a three-stage
pressure regulator.
Figure 2 is a perspective view of the outer surface of the body of the pressure reguiator
of the present invention.
0 Figure 3 is a top perspective view of the bo~y of the pressure regulator of the ,c,~sent
invention shown in Figure 2.
Figure 4 is a perspective view of the interior surface of the body of the pressure
regulator of the ~.r~sent invention.
Figure 5 is a perspective view of the interior surface of the bottom cover of the pressure
s regulator of the p, ~sent invention.
Figure 6 is a sectional view taken along line 6-6 of Figure 1.
Figure 7 is a sectiol)al view of the power valve asse",~ly taken along line 7-7 of Figure
1.
Figure 8 is a se~:tiunal view of the idle so'e lO;~ assembly and cranking solenoid
20 assembly, taken along line 8-8 of Figure 1.
Figures 9A and 98 are plan and front views, les,uecli~/ely, of the pintle lever used in the
pintle asse",~ly of the p,~sent invention.
Figures 10A and 10E3 are plan and section views, respectively, of the sliding coupling
used in the pintle asse",bly of the presenl invention.


WO9~117280 0 2 1 9 9 5 2 1 PC'rtCA9~1~0667

-1a-

Figure 11 is a sectional view of the s~F~'e."enl~ry pressure regulator of the present
invention in one preferred embodi-l~el)t as a third staye of a three-stage pressure
regulating system taken along a line generally coi ~esponding to line 6-6 in Figure 1.
Figure 12 Ts a sectional view of an aller--dle er~bod; ~enl of the regulator of the present
5 invention.
Figure 13A is a plan view of a preferred ~liaph,~yll~ a5se~bly used in the embodiment
of Figure 12.
Figure 1 3B is a plan view of an anti-wrinkle ring used in a ~ d diaphragm
asse,..bly of the present invention.
Io Figure 13C is a se~;tiollal view of a prerel,ed cJia~h,dy--. asse-..bly which may be used
in the embodi...enl of Figure 12.
Figure 14 is a sectional view of a p~felled shut-off solenoid assembly which may be
used in the pressure regulator of the ~lesenl invention.
Figure 15A is a partial plan view of the regol~or of Figure 12 shc.~,-;.,g the pressure
15 relief valve, the fuel lemperdlure sensor and third stage shut-off so!enoi~;
Figure 15B is a se-;tional view along line E-E of Figure 15A ShuVJ;.Isl the construction of
the pressure relief valve the fuel te""~6rdlure sensor and the third stage shut-off cavity
of the regu~ator of Figure 12.
Figure 16A is a side el iVdtiOI~ view of the .I;aph,dy", lever asser,.L)ly of the embo.li".enl
of Figure 12.
Figure 168 is a plan view of the .liapli,aylll lever asse",l31y of the e~,l,ocli."enl of Figure
12.
Figure 16C is an end view of the pintle slide coupler used in the prereil~d diaphragm
asse."bly of Figures 13A-13C.


WO96117:~80 0 2 1 9 9 5 2 1 PCT/C~95/00667

19

Figure 17 is a se.;lional view of anulller embodiment of the regu~tsr of the p,eser"
invention taken along a line generally co, l~suoIlding to line 6-6 in Figure 1.

MODES FOR CARRYING OUT THE INVENTION:
s In one of its p,~r~"ed embodiments, the suppiementary pressure regulator of
the pr~sent invention is used in co~llbinaliol- with a balanced two-stage pressure
regulator and may be constructed to receive and support such a pressure regulator.
The construction and operation of the supplementary pressure regulator of the pr~ser,l
invention will be des~ ed with particular r~fer~i)ce to that co,lter"~ulaled use although
lo it will be ~",der:jlood by those skilled in the art that the construction may be modified to
accG"",.od~le the use to which the su~,~!e ,-er,ld"~ pressure regulator of the pl~:selll
invention may be put, and the pressure regulators it will be used with.
Shown in Figure 1 is a partially sectiu"al view of the body 1102 of the pressureregulator of the presenl invention, which is ger.erally desiy..aled as 1100. In this
1~ pref~ d e",bo ii.,.ent of the invention, the reg~ tsr body has an upper surface 1116
which may be ada,.)led to coope,~le with or engage a single or multi-stage pressure
regulator such as the two-stage pressure regulator shown in co-pendi.,-J co-pend;.,g
Canaulia" patent ~ ca~;o,) No. 2,131 108. Rising vertically from the surface 1116 of
the regulator body is a mounting surface 1118 in which are formed a plurality of 20 mounting bosses 1122 which are adapted to permit secure f~ n;.,g of for exampie
the two-stage pressure regl~' tor as des~,ilJed above, to the third-stage body, by any
conve,llional, applup,iale means. Formed within the vertical surface 1118 is a fuel inlet
port in the form of a l,dn~rer passag~ J~dy 1120 through which the gas to be regulated

WO96/l728~ 0 2 1 9 9 5 2 1 rcTlc~95l~o6fi7
-20 -


may pass, from the ~,,i"u;,~al pressure regulator to the interior of the sulu~ emenla,y
pressure regulator of the present invention.
Ananged on the outside surface of the regulator body 1102 are a ,~"l~i"g
solenoid tower 1202 and an idle solenoid tower 1302. In the embodi",e"l of the
invention shown in Figure 1, a c ranhi"!J 501~n~ ' cavity 1204 is formed in the solenoid
tower 1202 and an idle solel1o ~ cavity 1304 is formed in the sc'~no . tower 1302. In
addition there is a shut-off solenoid tower 1402 in which is formed a shut-off solenc.J
cavity 1404 and a pressure adjustment tower 1406. Also a"dnged on the upper
surface 1116 of ths regulator body 1102 is a power valve adjustment tower 1502 and a
lo power valve tower extension (not shown) which has a mounted therein or inleyldlly
asse" b ed therewith a power valve outlet 1506.
In the embodiment shown in Figure 1 the co",l,onents of the cranking, idle and
shut-off scle.)c ~ towers and of the pressure adjustment tower, may be assembled from
the exle,ior surface of the regulator body and affixed to the body by conventional
15 means.
Around the p~,i,uhe,y of the body are mounting lugs 1106, which have in them
apertures 1108 adapled to receive screws bolts or the like (not shown~.
The body 1102 and the bottom cover 1104 of the su~,pl~ml:l,la,y pressure
reg~ tor of the pr~senl invention may be made or ~onned by any conver,lional means
20 such as moulding or casting, and the apertures and cavities formed by conveniiu,)al
machining methods. The body 1102 and the bottom cover 1104 as well as the exterior
cor."~onel,ts of the sa5enoi: and shut-aff towers may conveniently be made of
",alt rials such as metal or plastic.


~ WO96/17280 0 2 1 9 9 5 2 1 pcr/cA9~lon6fi7

-21 -

Shown in Figure 2 is the eAlerior or mounting surface body of a prefe"~d
embod;-"ent of the supplE.nenl~,y pressure reg~ak~r of the p~se~l invention generdlly
desiyllaled as 1102. In this pl~re.l~:d ei"bo-li."~nl of the invention, the regulator body
has an upper surface 1116 which may be ada,~)led to coope, ale with or engage a single
or multi-stage pressure regulator such as the two-stage pressure regulator shown in the
afc,re",el,lio"ed co-pendi"y patent ar,l)lic~ n. Rising ve~lieally from the surface 1116
of the regulator body is a mounting surface 1118, in which are forrned a plurality of
mounting bosses 1122 which are add,l~led to permit secure tdsteni"g of for exa~"r e,
the two-stage pressure regulator as ~esc.iLed above, to the regul~tor body 1102 by
lo any conver,lional, apprupriale means. ro""ed within the vertical surface 1118 is a fuel
inlet port in the form of a l,~nsrer passayvw~y 1120 through which the gas to beregulated may pass, from the pli"~;l ai pressure regulator to the interior of the
sl ~ F 1~ I lel lldl y pressure regulator of the present invention.
Alldllged on the outside surface of the regulator body 1102 are a cranking
sc'sn~ tower 1202 an idle so'~n d tower 1302 a shut-off ~olenci~ tower 1402 and a
third-stage pressure adjustment tower 1406. Also ai~dnged on the upper surface 1116
of the regu'~tor body 1102 is a power valve adJustment tower 1502 and a power valve
tower ekl~naion 1504, which has mounted therein or integrally asser, ~led ll,e,~ h a
power valve outlet 1506.
In this e",bodi."er,l of the invention, the ~rd,.l~i"g S0'9 oid cavity 1204 and the
idle s~le ~ cavity 1304 are fonned as in the ~."bodi"~ent of Figure 1, as is the third-
stage shut-off solsn ~ cavity 1404. The power valve adjustment tower 1502 may beforrned i"tey, d~ with the regulator body 1102 and a, ~nyeJ to enable the insertion and
asse",l,l~r of the power valve from the interior side of the regulntor body 1102.

~ WO 961172~0 0 2 1 9 9 5 2 1 PCI~/CA95/006G7
s -22 -

--
Around the periphery of the body are mounting lugs 1106 which have in ther
apertures 1108 adapted to receive screws bolts or the like (not shown~.
Referring now to Figure 3 there is shown a top ~ s~3eclive view of the body c
the regulator of the prt:senl invention shown in Figure 2. There can be seen in Figure
in addiliori to the cor"~3onersls shown in Figure 2, a fuel te"~per~ re sensor port 111(
adapted to receive an optional, convenlior,al fuel te",l~erdlure sensor assembly (nc
shown). This port may be plugged if a fuel te-"~ lure sensor assembly is not usec
Also shown in Figure 3 is a fuel supply passagavLc,y 1206 which extends through th
regulator body 1102 from the Cldnl~ill9 sclenoid cavity 1204, through the idle solenoi
cavity 1304 to the third-stage shut-off solenoiJ cavity 1404, and which is adapted t
enable relatively small amounts o~ fuel to flow from the ~i,dnki"g and idle solenoi
asseml~'ies to the third-stage shut-off assembly under start-up and idle condilion
respectively.
As ~;srlosed with respect to Figur~ 2 a power value adjustment tower 1502 wit
a tower exten~i~", 1506 may be ill~eyr~lly moulded with the regu~tor body 1102.
Figure 4 shows the lower side of the regnlator body 1102 of Figure 2 and i
particular shows a circu")i~rt,r,lial rim or flange 1150 c3es;~ned to cooper~le with th
bottom cover (shown in Figure 5) to define an interior cavity (as shown in Figure ~
within the regulq~nr body and which, when assen,~ ed with the bottom cover (shown i
Figure 5), en~ages and retains the edges of the regular didphray,., (not shown). Th
regulator body 1102 may have support ribs 1152 which may be integral with an
r~;.,rorce the upper surface 1116 (shown in Figure 2) and a central support rib an
diapl~taylll stop ring 1154. Support ribs 1152 may be used to sl,t:,,yulen the regulato
body 1102, depend;.,g on the ~l~e~y~ll of the Illalelial used to form the regulator bod


WO96117280 0 2 1 9 9 5 2 1 PCr/CA95/0(~667

-23 -

A cranking solenoid passagevL ~y 1206 extends through the surface 1116 to the
c,~nhiny ~ e:loid cavity (shown in Figure 2) and an idle solEnoid passage 1306 passes
through the upper surface 1116 to communicate with the idle sc e~.~ cavity (shown in
Figure 2).
s Mounted within the body are diaphragm lever mounting blocks 1130, adapled to
receive a dia~hr~ylll lever (shown in Figures 9A and 9B) and des~;.ibed in detaii below.
The support ribs 1152, the cëntral support rib and iiaphr~ylll stop nng 1154 and
the diaphr~g", lever mounting blocks 1130 may conv~r. ~ ,lly be made integral with the
regulator body 1102 and moulded or forged as part of the regulator body.
A pintle orifice 1408 commu"icates with the shut-off so enoid cavity, and
provides an inlet means for the gas to be regulated to flow from the shut-off solenoid
assembly 1400 through the pintle orifice 1408 into the cavity 1105 in the body of the
reg~ tor.
An outlet passag~ y 1508, which in the p,~fe.,e i ell~bocii.~ent is a
passa~ y through the power valve asse",bly 1500, provided an outlet means for the
pressure regu~ted gas to flow from the pressure reg~ tor to the engine. Within the
passageJ.a~ 1508 is a power valve index cha"-,el 1510 which prevents r~,lalion of the
flow control disc, des.;, ii ed in more detail with, t re, ence to Figure 7.
Figure 5 shows the boKom cover 1104 of the regulator housing of the regu'ntor
20 of the t,lt:se"l invention, which, togell,er with the regu~-'or body 1102 defines a
generdlly circular interior chamber or cavity 1105 shown in Figure 6. Provided within
the bottom cover is a rerer~nce pressure l~assage~dy 1138 which commu"icates
belu,~:en the interior of the regulator housing through a reference pressure lug 1142
defined within a rere,ence pressure port 1140. Surrounding the pe,i~l,ely of the bottom

W096117280 0 2 1 9 9 5 2 1 PCT/CA9~/OOG67

-24-


cover are mounting lugs 1106 co"espon m,g to those in the regulator body and having
apertures t108 adapted to receive screws, bolts or other like rasleners. In one
p,efer,ed embodiment of the invention, the ~t:r~rl:nce pressure port 1140 (lug 1142?) is
of sulJdlanlially the same size as the outlet passag~vJay 1608.
Figure ~ shows a sectiu~al view of the regulator of the presenl invention taken
along line 6-6 in Figure 1.. Shown in Figure 6 is the assemb'e51 regulator housing 1100
consisli"~ of the upper body 1102 and the regulator bottom 1104 joined through bolts
or other conventional fasteners 1114 pass;.,g through apertures 1108 in lugs 1106.
Between the abutting edges of the body 1102 and the bottom 1104 there may be
10 provided a gasket 1112 to Illaillldi,i a pressure-tight seal in the housing and to provide
means for holding the diaph~!Jm 1680 which logetl,er with the gasket 1112 is gripped
about its circu"~r~,e,-ce by the abutting edges of the body 1102 and the boUom 1104.
As shown in Figure 5, there is a sclenGid tower 1402 having an e~tensio,l 1406
thereon. Within the tower 1402 is a cavity 1404, comm~",;cali"~ with the second-to-third
Is stage passageY~ay 1120 (shown in Figure 1), and the third-stage pintle orifice 1408.
Defining the tlanailion behNeen the cavity 1404 and third-stage orifice 1408 is a collar
1410, shaped to receive the pintle assem~ly 1600, as desc,il~ed in more detail below
and to opli",ke the flow of gas betwcen the cavity 1404 and aperture 1408.
Mounted on the solenoid tower 1402 iS a shut-off ss n~i;J asse",bly 1400,
20 which cor,sisla of a sale.,c-.d oper~led piston 1420, having within its upper end a cavity
1421 adapled to receive and retain a piston retum spring 1422. The solenoid operated
piston 142Q is adapled to move within the cavity 1404. On the lower surface of the
piston 1420is an O-ring 1424 or other sealing means adapl.ad to engage and provide a
pressure-tight seal with the collar 1410. VVlthin the lower end of the piston is an aperture


WO9G/17280 0 2 1 9 9 5 2 1 PCr/C~9S/00667


1426 ad~l~led to receive the upper end of the pintle assembly 1600 desc~ii ed in more
detail below.
The piston 1420 may be operated by a shut-off so'eno:~ 1430 contained within
a solenoid yoke 1432. The screw 1434 fastens the yoke 1432 and shut-off solenoid1430 together fo""i.,g the shut-off assembly 1400 which provides a magnetic flux path
from the top to the bottom of the coil. The re~ulator screw 1434 holds the yoke 1432 to
the solens d piston 1420 and thus both clamps the solenoid coil 1430 and provides a
"aynelic flux path from the top to the bottom of the coil.
Commu";cdli"g with ths cavity 1404 is the passa~JJa~r 1206 from the idle
o solal,oid cavity 1304 and the ~ nl~ g solenoid cavity 1204.
Con~ai"ed within the tower e~ nsion 1406 is a spring cavity 1440 adapted to
receive a third-stage regulator spring 1442 which is adjustably mounted between a
third-stage adjusting screw 1444 and the third-stage regulator piston 1443 which is
co"nedecl to the pin 1636 of the pintle asse,.-~ly 1600. The operdl;"~J pressure of the
regulator may be adjusted by means of a third-stage adjusting screw 1444 which is
provided with an O-ring seal 1448 to ensure pressure-tight ope,alion of the adjusting
screw 1444. There is provision in the tower exter,sion 1406 for a tamper-proof plug
1446 which may be used to prevent ~",deai-~d adjustment of the upper pressure.
As shown in Figure 6, the pintle asse",l,ly 1600 is pivotally mounted on the
pintle lever mounting blocks 1130 (shown in Figure 4).
The pintle assembly 1600 culll~Jl;ses a pintle 1610 pivotally mounted on a pintle
lever asse",bly 1630, which is shown in greater detail in Figures 9A and 9B.
The pintle lever assen,bly is dis.losed in detail in Figure 9A. The pintle leverasse",bly 1630 co"".riaes a pintle lever 1632 having a transverse pivot arm 1634

WO 96/17280 0 2 1 9 9 5 2 1 PCI~/CA9~1OOGG7

- 26 -
. ~
adapted to be pivotally mounted to pintle lever mounting blocks 1130 (shown in Figure
4) by any convenUonal means. At one end of the pintle lever 1632 is a pin 1636 adapted
to engage a co~spondi.~ aperture in the third-stage regulator piston 1443 (shown in
Figure 6). At the other end of the pintle arrn 1632 is ~lia~hl~ylll pin 1638 adapted to
S engage the sliding coupling 1652 shown in Figures 10A and 10B.
On the side of the transverse pivot arrn 1634 opposite the pin 1636 is an
aperture 1640 in the pintle arm adapted to engage the pintle 1610, and bearing-
receiving apertures 1642 which pass through the pintle lever 1632 per,uenLl;cularly to
the aperture 1640.:
o Refeni~g again to Figure 6 the pintle 1610 has an aperture (not shown) in its
lower end through which an axle or bearing enga~ecl in the apertures 1642 may pass.
In this way the pintle is pivotally conne~led to the pintle lever 1630.
The diatances between the pin 1632 and the centre of the pivot arm 1634 and
between the centre of the pivot arm 1634 and the centre of ruldlion of the pintle 1610
as well as the spring cor,sldnl~ of the third-stage regulator spring 1442 and the pintle
leaf spring 1672, are selecled to ensure that the forces exerted by the spring 1442 and
the spring 167Z baid"ce each other at the centre of rolalioll of pivot arm 1634.
The pintle asse,-,bly 1600 co"",.i~es a pintle stem 1612 on which is mounted a
pintle flange 1610, which is adapleci to engage the annular collar 1410 and the O^ring
20 1424 when the pintle is in a closed posilio" to provide a suL~la"li~lly pressure-tight
seal. At the upper end of the pintle 1610 is a pintle head 1616 which is slidably
disposed within the aperture 1426 in the piston 1420. The lower end of the pintle stem
Colll;iill5 a circular groove 1697 which is used to retain the pin 1696. The pintle stem
slides in bea,i"g 1692 and is ~lai"ed by spring 1695 and clip 1696.

0 21 99 5 21
wo 96/17280 PC r/C~95100667

- 27 -

The shape of the pintle 161Q, of the co,-esporldi-,y annular collar 1410 and of
the pintle orifice may be sele~,leci to provide the most eri. ~nt gas flow around the pintle
1610 and through the pintle orifice 1408. This ensures that the pressure losses as the
gas fiows through the regulator may be controlled to the fullest extent possil,le, and
5r~ llkes losses that cannot be controlled or regulated.
The spring loaded slip joint allows the pintle to slide in the pivot bearing 1642 if
the force exerted on the pintle (by the pivot bearing 1642) in the closing direction
exceeds the force of spring 1673, whlch acts as a shoci< aissori er to cushion the
relative movements of the pintle asser"bly 1600 and the dia~h~aylll asse"~bly 16~0.
oThis allows the diapl"~m ba~,hiny piates to contact the lower cover without exerting
high forces on the backing plates, coupler, or lever in the event that excessive pressure
is applied to the third-stage diapHr~y"~ (excessive pressure may be applied during an
engine back-fire, a rapid decrease in fiow der"and, or by an i,ls, "Er blowing in the
outlet).
15The use of the slip joint also lowers the impact loading on the pintle seat when
exposed to the above corldilions, thereby reducing seat wear and the resulting set point
drift Associ~led with it.
Hence, incGr~-o,~lio" of the slip joint reduces set point drift and allows the
bachi"y plates. couple and pintle lever to be lighter, thereby improving t,ansie"t
20response.
The lower end of the pintle lever 1630 engages a sliding coupling 1652 formed
in the upper d;aph, dyl 1) backing piate 16~0 as shown in Figure 10.
A leaf spring 1672 may be mounted to the housing 1102 via screw 1671,
rc"",i"~ a canl~ /cr spring assel"bly. Dene~.1ion of tHe spring upon assembly applies a

~ WO96/17280 0 2 1 9 9 5 2 1 PCT/C~9~0n6fi7

-28 -

force to pintle stem 1612, balanc;ng the force i~ dll~d by spring 1442 at the centre of
rotation provided by the high pressure fuel against the pintle 1610.
The use of leaf spring 1672 permits the major portion of the regulating spring
force to be applied directly to the base of the pintle. A minor portion of the regulating
5 spring force is provided through spring 1442 as a means of adiusting the pressure.
Leaf spring 1672 and coil spring 1442 work in parallel and their forces on the pintle
asse")bly are additive. By applying the majority of the force directly to the pintle the
force that must be applied by spring 1442 is sul~s~anliaDy lower, resulting in siy"iricanlly
lower forces on the lever pivots. Thus, the h~teresis effect due to pivot friction is
lo greatly reduced over that in desiylls which apply the regulating spring force solely to the
lever. In addilio", the leaf spring deflects the jet of gas (exiting from the pintle onfice)
away from the diaphragm thereby reducing or elil"i"~li"g local pressure variations on
the Jidplll~ym and reducing any tendenuy of the Jiaph,ay", to tilt. In acldiliol~ any
debris which may be enl,~pp6d in the gas stream is also di,e-ted away from the
5 d;aph,~y"" thereby prule~li"y the diaph,~y", from pe,furdlion.
One prerer,ed form of a power valve asse",bly 1500 is shown in detail in Figure
7. This asse",~ly provides an adjust-~ e valve to regulate the amount of fuel that enters
the engine at a defined ter"~e,dl.lre and pressure. The ass~",~ly colnp,iaes a power
valve tower 1502 and a power valve tower e~ n:.ion 1504, each of which may be
20 i"ley,dlly forrned with the upper body section 1102 by for e~a"~!.'e moulding or
casting. Within the tower 1502 is a cavity 1503. Disposed within cavity 1503 is a flow
control disc 1510 axially mounted on a threaded adjusting screw 1512. The flow control
disc is urged toward a closed posilion by means of a pre-load spring 1514. Rotation of
the adjusting screw 1~12 causes the flow control disc to move u~ dldl~ or du~".~dly


WO96/l7280 O 2 1 9 9 5 2 1 PCT/CI~g~looG67

- 29 -

within the tower 1502 thus adjusting the size of the opening through which the
pressurized fuel may pass. An end stop screw 1520 prevents the flow control disc 1510
from coming offthe end of the adjustment screw 1512~
The cavity 1503 commu~:~rtes with the NGV outlet 1506 which may in turn be
connected to the engine by conventional means.
The end of the thr~aded shaft contains an O-ring to seal out the boost pressure
and is seated in a taper-bollomed hole to eliminate wobble. An internal spring prevents
the adjusting disc from rocking and prevents the adjusting screw from being pushed out
during high boost pressure~ Rotation o~ the adjusting disc is prevented by indexing
lo grooves in the regulator body. This arrang~",enl is readily ad.d~,lat.'e to stepper motor
operdlior,s.
Referring now to Figure 8, there are shown the cranking solenoid assembiy
1Z00 and the idle soleno ~ asse-"bly 1300. The cranking solenoid assembiy 1200 is
mounted above the c,ankil,g -o'.~n~ ~' cavity 1204 in the housing 1102. Cavity 1204 is in
g~seous communication via the idle supply passag~y 1206, with the third-stage
shut-off so!en. ~l cavity 1404, and the idle scl~noiJ cavity 1304~
The ~dnking s~'~n: asse~,lbly 1200 may co",~,ise any con~ "(ional solenoid
1210 capable of opening sa.'er.~ ~' piston 1212 against the pressures normally
encountered in the regulator. A gas flow passagQ 1214 conne-.b the cranking sc'enoi
cavity 1204 with the third-stage J;dl)hldylll cavity 1105.
The idle solen~-~ asser"~ly 1300 is mounted above the idle soleno:i cavity
1304, which is in gaseous comm~ .on via the idle supply passag~. dy 1206 with the
third-stage shut-off so'snoid cavity 1404 and the c~ dl ,hiny sole, loid cavity 1204.

WO96117280 0 2 1 9 9 5 2 1 PCI'ICA95100667

-30 -
.
The idle solanoi:l asseinLly may co"" -i~e any convenliol1al -~IE.IC ~ 1310
capable of openi"g solenoid piston 1312 against the pressures normally encountered in
the regulator.
A gas flow passage 1314 connecls the idle s~'enc:~ cavity 1304 with the idle
s flow adjustment cavity 1316.
Disposed within the idle flow adjustment cavity 131~ is a lhr~aded idle flow
ad~ustment pin 1318. The idle flow adjustment cavity 1316 is tapel~7d beco",i.,g
ployl~ssively narrow towards the interior of the regu~ntor. The idle flow adjustment pin
1318 has a similarly taperecl end 1320 which is di;.,~osed within the idle flow adjustment
lo cavity to provide an annular passage of a~just~ble size through which gas may flow.
The size of the annular passdye may be adjusted by turning the idle flow adjustment pin
1318 which has a threaded shaft to rotate within a ll"eaded portion of cavity 1316 thus
moving the tapered end portion in or out of the cavity 1316.
The idle flow adjustment pin 1318 regulates idle flow and has an adjustment
15 range of 20-96 SCFH. In ~n~ther e,-,bod;."~r,l of the invention, the idle flow
adjustment pin 1318 could be leplaced by a needlo valve to adjust for low and high idle
flows as required by the engine. The idle flow adjustment pin 1318 consisls of a finely
tl"~aded shaft connected to a tapered pin which may be tapeled at about 1.~ degrees
per side. An O-ring gland is conla;.,ed in the screw head 1319 to provide a seal. The
20 orifice seat may be ",acl,;"ed into the third-stage regulator body to reduce
manufacturing costs.
In Figure 11 the supplementary pressure regulator of the present invention is
shown in one pre~r,t:d embo~;,nent used as a third stage in conjunction with a two-
stage balaoced pressure regulator. The first stage spring tower 600 is shown in an


021 99 521
- ~ wo 961l7280 PC rlcA9~moGG7

- 31 -

exterior plan view and co",p,ises a spring tower cover 502, having an upper wall 5
and side walls 504. Between the upper wall ~03 and the side walls 504 is a shoul506. Details of the construction of the spring tower are d;sclosed in 3fore~"er,lioned
pendi"g Canadido patent applicatio".
The first stage spring tower may contain one or more springs whose sp
constants are selected to give the desired outlet pressures and extend the life of
regulator and its CGII~pone~
The spring tower cover 502 is adapled to be mounted on the base 10C
means of mounting bolts or other fasleni"g "echanis."s not shown.
o Figure 11 shows a seclional view of the second stage spring tower 700, and
su~,p!e.,~enlaly pressure regulator of the p,~senl invention as shown in Figure 6.
second stage spring tower 700 co,~pri~es a spring tower cover 702, which has an u
sur~ace 703 side walls 704 and a lower flange 70~. Between the side walls 704
the upper sur~ace 703 is a shoulder 706. The pressure within the second stage tow
re~elencsd to the third stage outlet pressure which may be dl",Gspheric pressureport or oper;"y in the cover 702 or in some other convenient locdliol,.
Within the second stage spring of the pressure regulator is a second stage F
asse."bly 708. A locking ring 707 is provided to secure the second spring t
assen.bly to the base.
Included within the second spring tower asse,.,bly are first and second h,
springs 710 and 712 ,t:~pe~ /ely which are in the p,ere"~d embod;.uent wou
opposite di.e~lions. The upper ends of ths springs 710 and 712 butt against a s
adjusting end cap 720 which can be ~ ced in a vertical direction by means
adjusting set screw 7~2, thus per-.,itli"g an adJustment of the force exerted b

WO96/17280 0 2 1 9 9 5 2 1 pcrlc~95lolK67


- 32 -


springs 710 and 712 against the pintle assembly 708. The adjusting set screw may
protected against unauthorized adjustment by tamper pl uoti"y 724 using any of sev~
known tamper-proc"i,lg means. The bore of this spring tower is larger than the bore
the co~8,~20n~;ag output char"ber to prevent the ~,iap~"dg,n piston ~rom shea,i"g I
5 diaphragm if the pintle fails.
The use of two cou,nter wound springs in the second stage tower assem
mi"i",i~as tower height and the spring consla(~l. By l";.,;"~i~iny spring rates for a gi~,
spring tower height this spring configuration leads to a lower degree of uncertainty
operali,ly pressure (droopn). Counter w;.,J;.~g of the springs ~,;i,;.~,i~es the risk of
o coils of the adjacent springs beco",i"g i"le,lo-.ked during movemerit of the springs~
As mentioned above, the presence of the rolling convolution provides a numl
of advantages including inc~eased longevity in the working life of the diaphragm, c
allows for greater tolerdnces in manufacturing the dia~,hrdylll. The rolling convolut
also eli."i.,ales the hyslelesis effect oll,en~ris2 found in a flat diaplhrdy", dur
5 operdtional d;s~lace".el)t of the did~l1ldylll. In yet an~"l,er prefer,e~J el"bo~'i",enl a
hatn style dia~hlay", (not shown) with a longer convolution may be used in place c
diapl1ra~u", with a pre-formed convolution. This may be used to ",;.,i",;~e the variatior
the di;d~hldyll~ area which may otherwise occur with ch~nyes in ,~/ositiur, of the pi
assemblies.
~o As shown in Figure 11 the second stage pintle assen,l~ly consists o
d;a~ohray~ " 7~2 gene~ crilly di~posed in a hol i~ ul llal di. ectiol), but having a roll
convolution 711 exte"di"g u~ dldly from the diaphragm 7~2 to provide a modifical
in the behaviour of the d;aph~ ay~

WO96117280 0 2 1 9 9 5 2 1 PCr/C~9~/006fi7

- 33 -
-
The diaphragm 752 is mounted on a lower diaph,dy-,l stop 758 which ha-
doJ.n. aldly turned outer edge 713 and central boss 760 exte"di,lg through the cen
of the diapllr~y"l 752. The d;apii,dy". is reta;-led on the lower iiaphldyl.~ stop
means of a diaph,dy", piston 754 and a locking ring 762. A spring damper 764
5 ,~lai"e i between the locking ring 762 and the upwardly exl~ndi"g outer circum~erer
of the upper Jiaphtaym piston 754. The spring damper 764 bears against the side w;
704 of the spring tower [shown in Figure 4~ but can travel along the walls dur
movement of the second stage pintle asse",bly.
Mounted within the central boss of the lower dia~hld~llll stop is a pintle st,
o 765 which may have a na.,uJlcd central por~ion and a head 76~ which is retained
place in the boss 750 by a pintle retainer 763. At the lower end of the flrst stage pir
ar,dngen~erlt is a valve pintle 770 ll"~dably engaged on the pintle stem 765. Ab
the valve pintle is a moulded rubbe~ seal 774. The siy"ir,cdlilly lower fiuid pressure~
the second stage pressure chd",ber permit the use of a moulded rubber seal with li
s risk of defo"-,dlion of the seal which might uU,er~;sa occur in the p,~se"ce of higl
fluid pressures more co,l",-only encountered in the first stage pressure chamber
desired a Teflon washer can be added betu~n the did~l"ag." 752 and the diapl"
piston 764 to provide enhd-.ce~ p,utectiùn during cold \,~eall,er. The Tefion washer ~
slow down the heat tlans~er to the diaphrdy"~ 752. Altematively the diai-Jl"dy", pisl
754 and the lower dia~ l"ay", stop 758 could be ce-~" - coated to provide s~
enhanced cold weather pe"u""ance. Fl"ll-e-i"or~ the configuration of the spring tov
cl~d",ber (at 714) can be aitered to provide a ~dead gas~ trap between diaphragm 7
and lower stop 758 to enllance cold weather pe. ru, IlldnCl~.


021 99 521
WO 96/17280 PCI'IC~9S100667
, .

- 34 -


Referring again to Figure 11 the fluid under pressùre enters the hous
through the inlet 103 lshown in Figure 1] and may pass through a filter assel"bly s
as that des~ ed in the afw~",e"~ioned co-penJ;.,g applicatio~. The nuid enters the ~
stage of the pressure regulator through the inlet port (not shown~ to a first stage pir
5 chamber, which is essenL-~y at the pressure of the gas storage cylinder. The fl
passes in a controlled Ina,lner through the gap bet~ n the first stage pintle seal
the pintle chamber walls and then to first stage pressure recovery section within
first stage spring tower.
The flow of the fluid through the first spring tower is regulated by the combi~
o force exerted by the regulator springs and the diaph.ayln which tend to move the pil
asse",bly towards an open ~ositiorl wl,ereas the pressure of the fluid in the pit
chamber acting against diaphr~y". 552 tends to move the pintle to a closed posilion.
The flow of the fluid through the second stage ~I,a",ber is regulated by
cG~nti~,ed ~orce exerted by the springs 710 and 712 and the ~liaphr~y"~ which tenc
move the second stage pintle asse,nbly towards an open position. The pressure of
fluid in the pintle char"ber 180 acting against the diapl,,dylll 752 provides an oppos
force which tends to move the second stage pintle to a closed posit;o". The d;api-"~
752 p,~,~/kJes a seal against the escape of the fluid up through the second stage to~A
and perrnits a smooth vertical movement of the second stage pintle belu~ell the clo~
o and fully opened positior,s. The lower dia~.hray", stop 7~8 defines the top wall of
upper portion 216 of the second stage output cl,d",ber.
A ledge 717 is provided in the output cl,alnber 216 to engage outer edge 71
the lower dicl~,llr~ylll stop 7~8 and thereby prevent d;-pl~cel"ent of the second st~
pintle asse,.,bly beyond a set point. The second stage output ch~",ber il,co"uo,~te


021 99 521
WO96/1728n PCl'lCA9~ 0~fi7

e~ ~ 3~i -
spiral ramp (not shown) to further reduce droop. The ramp ~ er~les higher
velo~;ilias and a smoother l,~r,a;tiol~ to the outlet. The ramp may be i-,co".ordted i
the base by using forging techniques which are typically less costly than ,"ach;. .in~. 1
regulated fluid then passes through the output passaye 156 whlch commu";cates v
5 the outlet port 106, shown in [Figure 1].
A removable end cap 780 is provided to enclose the lower portion of the sec~
stage pintle chalnber 180. An O-ring 782 is provided to form a seal betv/e~n
regulator base 100 and the second stage end cap 780.
Figure 12 shows a secliollal view of a second embodi",ent of the regulato
o the p,eseht invention, taken along a line 96llel~11y co"~)orn~i"~ to line 6-6 in Figur~
Shown in Figure 12 is the assEm~led reguiator housing 2100, consialint of an up
body 2102, and a regulator bottom cover 2104. Each of the regulator body 2102;
the bottom cover 2104 are gene.~lly bowl-shaped and may convenien(ly
manufactured of plastic or other li!~l,l.r~ Jllt m~l~rial, in view of the relativ~ly
~5 pressures encountered within the regulator.
Each of the regulator body 2102 and the bottom cover 2104 may hav~
c6hlldlly dia~.osed i"~:~.dly.extend;"~ ridge 2114 and 211~"~s~,ectively, which serv,
al,el,yU,e,. and ,~i.,ro,~e the regulator body and whlch act as a support and stop for
didpllla$~lll asse~"bly 2700. The regul-tor body 2102 n~ay be provided with upwa
to e~ctend;.~s~ support members 2103, which may be integldlly moulded or formed with
regulator body 2104 and which are adapteJ to support a primary or two-stage regulc
The support members 21û3 are adapted to hold the primary reguiator (not shown)
pOâiliOn substantially perpendicular to the mounting surface 2118 to ensun
suL~tahlidlly pressure-tight COhl ,e~;tio" bet~:~cn the two regul?tors. Between


021 99 521
WO 96tl7280 ~CI-/CA9~/OOG67
- 36 -


abutting edges of the body 2102 and the bottom cover 2104 there may be provided
gasket 2112 to maintain a pre5sure-tight seal in the housing, and to provide means ft
holding the outer edges of diaphray", 2680, which, togell~er with the gasket 2112,
gripped about its circumference by the abutting edges of the body 2102 and the bottol
cover 2104. In one preferred embodiment of the invention, the diapl,,~y", 2680 and th
gaslcet 2112 may be integrally moulded in one piece to reduce the number of parts i
and the time required to assemble, the pressure regulator of the present inventiol
Each of the upper body 2102 and the boffom cover 2104 have outer edges adapled I
fit snugly against the corres~ond;-~ outer edge of the other to forrn a su~stantial
pressure-tight seal. Around the circumference of each of the upper body 2102 an
bottom cover 2104 are circul~"elenlial flanges 2106 and 2107, respectively, which ar
ada~ted to receive a ~la""~i~,g band or other means to hold the regulator body 2102 an
the bottom cover 2104 togell-er in a sub-~lal,tially airtight manner.
The regulator body 2102 includes a solena ~' tower 2402, generally circular in cros~
section, with an out\,vardly extending e~le"siol) 2406, as may also be seen, for exampl~
in Figure 15A. The so'enoi~ tower 2402 is adapled to receive the so'~no ~.' assei"bl
2400 and a regulator spring assel"l,ly 2440 as de~-;,ibed in more detail below. Withi
the s~ten~;~' tower 2402 is a cavity 2406, providing an inlet to the regulator of th
,url:sent invention and communicating in one er"bodi."enl with the outlet 1120 of th
primary regll'ator (as shown in Figure 16), and the pintle oriflce 2408. Defining th
llal)siliGIl bet~,veen the cavity 2404 and pintle oriflce 2408 is a collar 2410, shaped t
receive the pintle assembly 2600, as desc,il,ed in more detail below, and to optimiz
the flow of gas between the cavity 2404 and pintle orifice 2408.


WO 96117280 PCIlCA9~i/00667
- 0 2 1 99 5 2 1
- 37 -

As will be des~;,il-ed in more detail with reference to Figure 14, the regulatorthe present invention provides is a shut-off soienoid asse"~bly 2400, which cor"~,i,es
solenoid-ope,aled piston 2420, having within its upper end a cavity 2421 adaptedreceive and retain a piston return spring 2422. The solen -5 operated piston 2420
adapled to move within the cavity 2404. On the lower surfacs of the piston 2420 is;
O-ring 2424 or other sealing means adapted to engage and provide a pressure-tic
seal with the collar 2410. Within the lower end of the piston is an axial aperture 24
ada,oted to receive the upper end of the pintle assembly 1600 cleso,iiJed in more de~
below.
The piston 2420 may be operated by a shut-off solenoid 2430 cor,lai.,ed witl
a solen~ d yoke 243Z. The regulator screw 2434 holds the yoke 2432 to the solenlpiston 2420 and thus both clamps the solenoid coil 2430 and provides a magnetic n
path from the top to the bottom of the coil.
Commu,.icali.lg with the cavity 2406 is a fuei supply passag~ ;3y 2206 from 1
s idle solEn~ ~ cavity 2304 and the cranking solenoid cavity 2204.
The lower section of the pintle orifice 2408 is defined and shaped by an ins
2412 which may be made of metal to provide a durable surface over which the c
may flow, and which may be retained in the regulator body 2102 by (I"~acJs or otl
conve"lional means. Provision of such an insert ma;.,l~:.,s the durable and fo
o retaining surface required to define the pintle orifice while pei-llilling much of
remainder of the regulator to be made of low-cost liyl,l~ hl ",ate~i~ls. The in~2412 and the pintle asse-"bly 2600 are configured to provide the desired characteris
to the gas flow through the regulator as desc, ibed in more detail below.

WO96117280 0 2 ~ 9 9 5 2 1 Pcr/c~gs/00667

- 38 -


Within the tower extension 2406 Is a regulator spring asse" lbly 244(
comprising regulator spring 2442, which has spring caps 2443 at each end thereof. Th
regulator spring 2442 is d;~posed bel-~ecn a regulator piston 2446 and a pin 26
mounted on the pintle asse,-lbly 2600. Spring caps 2443 enga~e the regulator pisto
2446 and the pin 1636 r~spe~ ely. Regulator piston 2446 is ~ posed within the sprin
cavity 2438 and held by regulator spring 2442 against adjusting screw 2450. Adjustin
screw 245û is threadably received at the upper end of cavity 2438; its posilion withi
that cavity may be a~justed by rotating the screw to move it up or down within the cavi~
2438. The oper~lil,g pressure of the regulator may thus be adjusted by the adjustir
screw 2450, which is provided with an O-ring seal 2448 to ensure pressure-tigl
ope.alior) of the adjusting screw 2450. A tamper-proof plug 24~2 may be used in t~
tower extension 2406 to prevent undesi~ ed adjustment of the upper pressure.
As shown in Figure 12, the pintle assell~bly 2600 is a pintle 2610 pivotal
mounted on a pintle lever asse~ ly 2630, which is shown in detail in Figures 16A ar
16B.
The pintle 2610 is shown more clearly in Figure 14, and co,nplises a pintle ste~
26t2 which ",e-~es smoothly into a pintle base 2614, which is ad3pled to interact wP
the insert 2412. A sol ~-oid piston 2420 has an O-ring seal 2424 which provides
s~ la,llially pressure-tight seal betu.een the sc!e..s:~ piston 2420 and the collar 241
when the pintle is in a closed posilion. At the upper end of the pintle 2610 is a pint
head 2616 which is slidably di~posecl within the aperture 2426 in so's:)s d piston 242
Below the pintle base 2614 is a lower pintle stem 2616 to which is fastened a pint
support pin 2618, which rests on, and is sul.polled by, the pintle lever assembly 26
as des~ ibed in more detail below.


WO96/17280 0 2 1 9 9 5 2 1 pcTlc~s~looGfi7

.~ - 39 -

The shapes of the pintle 2610 of the co"~spo"di"~ annuiar collar 2410 and
the pintle orifice insert 2412 may be selected to provide the most efficient gas nc
around the pintle 2610 and through the pintle orifice 2408. This ensures that tlpressure losses as the gas flows through the reg~ tor may be cont,olled to the fulle
extent possible and ~"i"il"kes any pressure losses that cannot be controlled
regttlated.
The pintle lever assembly 2630 is disclQsed in detail in Figures 16A and 16
The pintle lever asse",Lly 2630 co"".,i~es a pintle lever 2632 having pivotally mount~
a~acenl to one end on a mounting pin 2634. At that end of the lever 2632 is a supp~
pin 2636 adapted to engage a co~spondi~lg aperture in spring cap 2443. Mounted
the other end of the pintle ann 2632 is co~pling pin 2637 adapted to engage the slidi
coupling 2652 shown in Figures 168 and 16C.
As shown in Figures 16A and 168 the pintle support lever 2632 has mounl
thereon on the side of a pintle guide assembly 2638 which is adapted to support 1
s pintle support pin 2618i which rests on the pintle guide asse",bly 2638.
As shown in greater detail in Figure 14 the pintle guide asser"bly 2638 incluc
lateral supports 2640 a c~ntral shaft 2642 a spring support 2644, and a spring 26-
Mounted at the bottom of the shaft 2642 are spring hooks 2648. Cor,~sponding sprhooks 2650 are l-:td;lled at the bottom of the sc enoid tower 2402 on either wide of
o pintle orifice 2408 by the insert 2412. Mounted betY.ee.l cor,espol,di.,g pairs of spr
hooks 2648 and 26~0 are pintle support springs 26~2.
The dislances belween the pin 2636 and the centre of the pivot lever pin 26
and betY:een the centre of the pivot arm 2634 and the centre 2618 of the pintle gu
assel,~bly as well as the spring consldl~ts of the regulator spring 2442 the pit

0 2 1 9 9 5 ~ 1
- . wo 96tl7280 PC rlC~95/006~,7
-40 -


support springs 2652 and the spring 2646, are seiected to ensure that the force exerte(
by the springs 2442, 2646 and 2652 balance the force exe~led by high pressure fue
against the pintle 2610.
The spring 2646 pushes upward against the pintle asse~bly 2610 and normall
holds the pintle assembly 2610 away from the pintle lever a5sembly 2630, and permit~
the lever asse",bly to continue moving downwardly even after the pintle base 2614 i!
cG",p'~lely seated in the insert 2412, and the pintle orifice 2408 col,~ l 'y closed
This allows the diapl)layll~ bacl~i"g plates to contact the lower cover without exertin!
high forces on the. backing plates; coupler, or lever in the event that excessive pressun
is applied to the third-stage diapl7,~y",. Such excessive pressure may be applie
during an engine back-fire, a rapid ~lec,ease in flow demand, or by an installer blowin
in the outlet. This permits the use of lighter materials in the construction of the leve
asse",bly 2630.
The use of the spring 2646 also lowers the impact loading on the pintle se~
when e~osecJ to the above co"ditions, thereby reducing seat wear and the resulting s~
point drift associaled with it.
Ir,cor~ o~lion of the spring 2646 reduces set point drift and allows the backin
plates, and pintle lever asse~ ly to be lighter, thereby improving the l~d"a;ent r~a,uOnS~
of the re~'ator.
The lower end of the pintle lever 2632 engages a sliding coupling 26~2 forme,
in the ~upper diaph~;~ylll bachi"g plate 2704 and operdles in the same manner as th~
sliding coupling shown in Figure 10.
The use of pintle springs 2652 permits the major portion of the regulating sprin
force to be applied directly to the base of the pintle 2610. A minor portion of th


02199521
wo 96/l7280 PC rlc~95l~o667

~~ -41 -

regulating spring force is provided through regulator spring 2442 as a means
adjusting the pressure acting u~,~Jardly on the pintle. Springs 2652 and spring Z4
work in parallel and their forces on the pintle assembly are additive. As is the case u
the embodiment of Figure 6, by applying the majority of the force directly to the pin
the force that must be applied by spring 2442 is subslanlially lower than that appliec
convenliol)al pressure regulators, resulting in s;g"irlcal,lly lower forcss on the le
pivots. Thus, the hysteresis effect due to pivot friction is greatly reduced over tha
des;yl ,s which apply the regulating spring force solely to the lever.
Figure 14 shows a section view of the s~ 5 ~ tower of Figure 12, taken at ri
o angles to the section view of Figure 12. As shown in Figure 14 the pintle asse~
2600 is su,upolled not only by the pintle lever asselnbly 2B30 but also by springs 2
which are engaged on spring mounting hooks 2648 and 2650. Thus the downw
force of gas flowing through the pintle orifice 2408 may be balanced against the upw
forces provided by springs 2652, and regulator spring 2442.
An alle",dle and p,~r~,.ecl power valve asser"bly 2500 is shown in detai
Figures 15A and 15B. This asse",bly provides an adjust~hle valve to regulate
amount of fuel that enters the engine at full power, and to ensure that the outlet
turbulent at all flow rates. The power valve assel"bly 2500 is mounted in a power v~
tower 2502 and a power valve tower exlel,~ion 2504, which may be i"le,y,~lly forr
~o with the upper body section 2102 by, for example moulding or casting. V\/lthin
tower 2502 is a generdlly cyl;"dlical cavity 2503. The cavity 2503 communicates
the NGV outlet 2506 which may in tum be con--e~ed to the engine by conventi~
means. D;;.~.osed within cavity 2503 pe",endicular to the longitudinal axis of the ca
is a flow control disc 2510 axially mounted on a ll"~aded adjusting screw 2512

021 99 521
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shown on dl~Y:;n~]. The flow control disc is urged toward a closed pO5itidll by means
a pre-load spring 2514. The upper end of adjusting screw 2512 is ex,uosed through 1
upper end of the power valve assa,-,bly and may be rotated to cause the flow conl
disc to move upwardly or downwardly within the tower 25~2 thus, adjusting the size
the open;ng through which the pressurized fuel may pass. An end stop screw 25
prevents the flow control disc 2510 from coming off the end of the adjustment scr~
2512.
The end of the thr~aded shaft CGntaill5 an O-ring to seal out the boost press~
and is seated in a taper-l~ollol"ed hole to l;."i"ale wobble. An internal spring preve
o the adJusting disc from rocking and prevents the adjusting screw from being pushed ~
during high boost pressure. Rotation of the adjusting disc is prevented by indexi
grooves in the regulator body. This ar,a,,yell~ellt is readily ada~table to stepper mo
oper~liG"~ lmore details and numbers needed in d~w;ng].
Shown in Figure 15B is a sectional view of the solenoid tower 2402 and t
pintle orifice 2408 with the collar insert 2410. Shown in Figure 15B are the spri
mounting hooks 2650 on which the plntle support springs 2652 are mounted.
Also shown In FTgure 15B is a temperature sensor port 2800 which has
U,e,l";;.lor 2801 mounted UI~l~Gn, with the te",peralure sens;.lg end of the thermis
exlendi.,~ into the cavity 2408 in the pressure regulator.
o Also shown in Figures 15A and 15B is the idle supply passa~e~dy 2306 whi
connect~ the idle scl noid cavity 2304 with the third-stage shut-off sc'enDk. cavity 24
and the cranking s~ sno.d cavity 2404.

0 2 1 9 9 5 2 1
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In a ~"allner similar to that of the embo.li",ent of Figure 8, a gas flow passa
connects the idle solenoid cavity in the idle solenoid tower 2302 with the idle fl
adjustment cavity 2316.
At the end of the idle supply passagcuay Z306 is an idle flow adjustment ca
2316~ D.sposed within the idle flow adjustment cavity 2316 is a lh,t:aded idle fl
adjustment regulator (not shown in Figure 15B but similar to that shown in figure 8). l
idle flow adjustment cavity 2316 Is taper~d becoming ployl~jsively narrow towards
interior of the regulator. As shown in Figure 8 the idle flow adjustment pin 1318
Figure 8~ has a similarly ta~6r~d end 1320 (in Figure 8) which is di~posed within
o idle flow adjustment cavity to provide an annular ,uassa9e of adjust~hle size throl
which gas may flow. The size of the annular passage of the enlbodi,l~e,ll of Figure 1
may be adjusted by turning the idle flow adjustment pin 2318 which has a threa~
shaft to rotate within a threaded portion of cavity 2316 thus moving the taper~
portion in or out of the cavity 1316.
Shown in Figures 13A, 13B and 13C is an especi~lly plef~ d diaphra
asse,llbly 2700 which may be used in the enlLodi.llents of the regulator shown in Fig
12.
Th~ l~id,~ Idylll asseh.1~1y 2700 co..~,.ises a Jid~ aylll 2702 which may
made of any convenliol,al ,.~dle.ials whose outer edges are held securely between
~o regulator body 2102 and the bottom cover 2104 (as shown in Figure 12) and inclu
an integral moulded gasket. Above the dia~ dy~l~ is a ~lidlJhlay", bachi"g plate 2
to which is mounted the sliding coupling 26~2 as shown in Figure 12.
Below the diapl"dy,ll is a didph"dy"~ spring 2706 and an anti-wrinkle ring 2
The bac~i"g plate 2704, didph~ay~n spring 2706, and anti-wrinkle ring 2712 are joi

:


Wo96rl7280 0 2 1 9 9 5 2 1 PcrlcAss/oo667

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togell,er by rivets 2714 or other li~ t ra~tener~ that pass through the diaph,~y",
27~2 but still perrnit a s~,l.sl~"li~lly air-tight sepa~dti~,n bel- _an the upper and lower
po,lions of the regulator cavity The d;d~hldylll spring 2706 may co,.,pri,e three or
more fingers extending outwardly from a central hub and adapted to support the anti-
s wrinkle ring in the l"anner des-;, ibed below.
The backi"g plate 27~4 may be a relatively flat ligl,l~ei~l~t piece of metal or
plastic configured with spokes and a continuous outer circ~",r~:r~nce to keep the mass
of the ba~hing plate as lo~,v as possible while ke~p ,5J the central portion of the
diaphrag", 2702 relatively flat and parallel to the central axis of the reg~ tor body.
o Similarly, the anti-wrinkle ring Z712 has a circular outer ririg 271Q of a diameter
greater than that of the bacl~i.,g plate 2704 which is mounted on elevating pins 2716 at
the end of spring fingers 2706. The outer ring raises the diapl,.dylll edges above the
height of the central portion of the diaph~y"~ in the regulators normal or balanced
posilion. If the pressure in the upper portion of the cavity 2105 drops below the
It:rt:,~"ce pressure in the lower portion of the cavity, the central portion of the
diaphl~", will move up to cG",I,ensale for these pressure differencPs. The novelconstruction of the Jia~ dylll of the p,~senl invention keeps the diapl),~g", flat and
improves the operdlion of the regulator.
While in many cases it will be p,~rt:r.~:d to operclle the regulator in a balanced
20 po5;tion, to ",i.,i~ e the outlet pressure of the gas there are circualdnces in which
the regulator may be operdled Tn an unbalanced po-~iliGn to ensure that there is a small
positive outlet pressure from the regulator to the engine.
Shown in Figure 17 is the pressure regulator of Figure 12 ~d~rted to ensure a
positive output pressure from the regulator. Mounted on the bottom cover of the

A Wo 96117280 0 2 1 9 9 5 2 1 PcTIcAgslon6~7
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pressure regulator is a spring tower assembly 2800 co"~,is;-,g a sleeve 2802 mounted
in the bottom cover and held in place by a nut 2804. Within the sleeve 2802 are
counterwound springs 2806 and 2808 ~eta;ned bet~en spring plates 2810 and 2812.
Spring plate 2812 is fastened to the ~liaph,ay", assembly 2700 by rivets 2714 while
S spring plate 2810 is retained within sleeve 2802 and abuts against a spring adjusting
disc 2814 which is ~I,readedl~ received in the sleeve 2802. Rotating the spring
adjusting disc 2814 increases or decr~ases the spring force applied against the
diaph~aylll asse")bly 2700. A tamper-proof cap 2816 may be provided at the end of the
sleeve 2802 O-rings 2818 and 2820 seal the regul~tor against the effects of a~"t-ent
lo pressure.

Representative Drawing