NZ330311A - Cng fuel regulating apparatus for ic engines and gas regulating valve and engine speed governor - Google Patents

Description

330311 Under the provisions of Regulation LJ tha Specification has been ante-datod ' to 19 4k -fa Q Initials omii>miimm»»*iHw>i*itiiw»l WtMINHMMtllHMMMH No: 272065 Date: 4 May 1995 NEW ZEALAND PATENTS ACT, 1953 COMPLETE SPECIFICATION "Fuel Regulating System" We, TRANSPORT FUEL SYSTEMS LIMITED, a company duly incorporated under the laws of New Zealand of 440 Church Street, Penrose, Auckland, New Zealand, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 330311 The present invention relates to a gas regulating system and in particular although not solely to a CNG fuel regulating apparatus for combustion engines.

Gas regulators which are currently known are either too costly or are inefficient at supplying an accurately regulated supply of gas and of fuel to combustion engines. The most common problem is a poor control over the gas output pressure from a fuel regulator over a range of input pressures from a high pressure when the gas supply reservoir is full, to a low pressure when the gas in the gas supply reservoir is mostly depleted. This poor control of the output pressure varies the amount of gas delivered by a regulator as the input pressure varies. Such poor control directly effects, for example, the performance of the engine to which the gas is supplied. The easiest way currently known to overcome this problem is to use at least three stages of pressure reduction, but this is considerably more expensive than a two stage reduction and also much more complex.

It is therefore an object of the present invention to provide a gas regulating system with an accurately regulated gas pressure output through a broad range of gas input pressures.

Accordingly, in a first aspect the present invention consists in a gas supply regulating apparatus for gas from a pressurised reservoir to apparatus requiring such a gas, said gas supply regulating apparatus having or including: (I) an inlet valve for an inlet from said reservoir having a valving element or assembly moveable from a closed seated condition to an open gas flow allowing condition (ii) a first chamber to receive gas via said inlet valve, said first chamber being variable as to volume by first chamber diaphragm, piston or other periphery changing means, there being inlet valve linkage means between said first chamber diaphragm, piston or other periphery changing means and the valving element or assembly of said inlet valve whereby (a) when the volume in said first chamber increases due to an increase in gas pressure therein, said valving element or assembly of said inlet valve increases the restriction of gas flow through said inlet valve into said first chamber, and whereby (b) when the volume in said first chamber decreases due to a decrease in gas pressure therein, 330311 said valving element or assembly of said inlet valve decreases the restriction of gas flow through said inlet valve into said first chamber, (iii) a second chamber to receive gas flow from said first chamber into a first region thereof partitioned from a second region thereof, said means partitioning (the "partition") the two regions of said second chamber being moveable so as to affect the respective volumes of the regions of said second chamber, said first region including (a) a first gas outlet controlled by a first region valving element carried by said partition and movable therewith from a closed seated condition to an open gas flow allowing condition and including (b) a second non valved gas outlet to said second region, said second region including a second region gas outlet, (iv) a third chamber, said third chamber being variable as to volume by a third chamber diaphragm, piston or other periphery changing means, said third chamber being able to receive gas flow from said first region of said second chamber through the controlled said first gas outlet, and via an outlet from said second chamber controlled by a third chamber valving element carried by said third chamber diaphragm, piston or periphery changing means, said third chamber including an outlet to that apparatus requiring gas, and wherein when apparatus requiring gas has no demand for said gas, the pressure in said third chamber is such that said third chamber diaphragm, piston or periphery changing means locates said third chamber valving element such that substantially no gas flow can flow from said second chamber into said third chamber via said outlet from said second chamber, and therefore no gas flow occurs through said inter valve through said first and second chamber into said tliird chamber, and wherein apparatus requiring gas has a low demand for said gas, the pressure in said third chamber is lower than at said no demand, reducing the volume in said third chamber by movement of said third chamber diaphragm, piston or periphery changing means, resulting in a reduction in flow restriction through said third chamber valving element, allowing gas flow through said second non valved gas outlet into said second region and flow from said second 33031 chamber into said third chamber through said outlet from said second chamber, the pressure of said gas in said first chamber being lower than at said no demand, reducing the restriction of flow through said inlet valve allowing said gas flow received through said inlet valve, through said first chamber, at said low demand for gas, the pressure inside said first and second region of said second chamber are equal, keeping said first region valving closed, and wherein when apparatus requiring gas has a medium to high demand for gas, the pressure in said third chamber is lower than at said low demand, reducing the volume in said third chamber by movement of said third chamber diaphragm, piston or periphery changing means, resulting in a further reduction in flow restriction through said outlet from said second chamber, resulting in said flow through said second non valved gas outlet not able to meet the demand from said apparatus requiring gas, resulting in a reduction in pressure in said second region, relative to said first region, causing said partition to displace increasing the volume in said first region, and lifting said i first region valving element from a closed seated condition to an open gas flow allowing condition, allowing ^as flow from said second region to flow through said first gas outlet into said third chamber, and to said apparatus requiring gas via said inlet valve and said first chamber from said reservoir, Preferably a governing passageway is present between said first region and said second region having a governing valve controlling gas flow there through such that when the gas flow out of said apparatus reaches a limit, or a preset engine speed is reached said governing valves open to allow pressure equalization in both regions.

Preferably said first chamber diaphragm, piston or other periphery changing element is a diaphragm having secured to a displacing or displaceable element thereof, a first end of said linkage.

Preferably said first chamber diaphragm is biased by a biasing means, in a direction to decrease the volume of said first chamber.

Preferably said sealable element or assembly of said inlet valve, is a shuttle moveable between limits from a closed seated condition to an open gas flow allowing condition, moveable in a shuttle chamber, said shuttle having a first surface onto which -5 330311 the gas from the pressurised reservoir acts in a first direction, and a second surface onto which the gas from said pressurised reservoir acts in a direction opposite to said first direction, said first and second areas being of equal pressure area such that the • force due to the inlet pressure is substantially zero, and a means of pressure equalizing.

Preferably said pressure equalising means is a passageway through said shuttle, allowing gas flow there through for the gas acting on said first area to a second area chamber.

Preferably said shuttle has secured thereto the distil end of said linkage. Preferably said means partitioning the two regions of said second chamber is a diaphragm, having secured to a displacing region thereof said first region valving element and a means to bias said second chamber diaphragm in a direction to encourage said first region valving element to remain in a closed seated condition. Preferably said means to bias said first chamber diaphragm is a spring. Preferably said means to bias said second chamber diaphragm is a spring. Preferably the flow of gas is also controllable by an external calibrating means linked to third chamber valving element.

Preferably said third chamber diaphragm, piston or periphery changing means is a diaphragm having associated to a displacing/dis ik sable region thereof a third chamber diaphragm linkage member, said linkage ncr. ber communicating the displacement of said third chamber diaphragm to said third chamber valving element, to control the inflow of gas from said outlet from said second chamber.

In a second aspect the present invention consists in a balanced first stage valve for the regulation of gas in or for a gas regulating apparatus comprising, means defining a chamber having a gas inlet and a gas outlet, shuttle means capable of substantially closing gas flow between said inlet and outlet, biasing means to move said shuttle means to a condition not substantially closing said gas flow, and means responsive to the gas outlet pressure (affected by demand for gas outlet) to apply outlet pressure dependent forces on the shuttle to affect its movement, the construction and arrangement being such that the gas pressure on said shuttle in said 330311 chamber is such that one gas pressure x area force on said shuttle is substantially balanced by the opposing gas pressure x area force thereby rendering the shuttle primarily movably by said biasing means and said means responsive to the gas outlet pressure.

In yet a further aspect the present invention consists in an engine speed governing apparatus for governing gas supply to apparatus requiring gas, said engine speed governing apparatus having or including: a chamber to receive gas flow from an inlet into a first region thereof partitioned from a second region thereof, said means partitioning (the "partition") the two regions of said chamber being moveable so as to affect the respective volumes of the regions of said second chamber, said first region including (a) a first gas outlet controlled by a first region valving element carried by said partition and movable therewith from a closed seated condition to an open gas flow allowing condition and including (b) a second non valved gas outlet to said second region, said first gas outlet being to said apparatus requiring gas or some intermediate means, said second region gas outlet being to said apparatus requiring gas or some intermediate means, said second region including a second region gas outlet, (c) a third valve outlet to said second region, the flow of said gas through said third valve outlet controlled by a governing valve which is controlled by said app;iratus requiring fuel, and wherein apparatus requiring gas has a low demand for said gas, the pressure at said first gas outlet and second region gas outlet is low, resulting in a flow through said valving element, allowing gas flow through said second non valved gas outlet into said second region and flow from said second chamber into said apparatus requiring gas or some intermediate means, the pressure inside said first and second region of said second chamber are equal, keeping said first region valving closed, and wherein when apparatus requiring gas has a medium to high demand for gas, the pressure at said first gas outlet and second region gas outlet is lower than at said low demand, resulting in a reduction in flow restriction through said outlet from said second chamber, resulting in said flow through said second non valved gas outlet not able to meet the demand from said apparatus requiring gas, resulting in a reduction 350311 in pressure in said second region, relative to said first region, causing said partition to displace increasing the volume in said first region, and lifting said first region valving element from a closed seated condition to an open gas flow allowing condition, allowing gas flow from said second region to flow through said first gas outlet to said apparatus requiring gas or some intermediate means and wherein when supply of gas through said engine speed governing apparatus exceeds a pre set limit, said governing valve will reduce the flow restriction through said third valve outlet bringing pressures in said first and second regions to an equilibrium, reducing flow through said first outlet and to said apparatus requiring gas.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

One preferred form of the present invention will now be described with reference to the accompanying drawings in which; Figure 1 illustrates a preferred form of the present regulator the regulator being in a state, wherein there is no demand for gas from apparatus requiring gas; Figure 2 illustrates the regulator as illustrated in Figure 1, there being a low demand for gas from apparatus requiring gas; Figure 3 illustrates the preferred form of the invention as shown in Figure 1, there being a high demand for gas from apparatus requiring gas; Figure 4 illustrates a balanced first stage valve, as used for the first stage pressure regulation; Figure 5 illustrates a graph of first stage pressure variation in relation to reservoir pressure variation, for currently known pressure regulators; Figure 6 illustrates the invention with the governing passageway opened; and Figure 7 shows a flow chart of the gas regulating apparatus as connected in use; 330311 Figure 8 illustrates an alternative means of pressure variation in the second camber; Figure 9 illustrates a detailed view of the first gas outlet; Figure 10 illustrates a conventional known valve controlled by outlet pressure; Figure 11 illustrates the speed governing apparatus; Figure 12 is a detailed drawing of the preferred form of the balanced first stage valve of the apparatus of the present invention; Figure 13 is a partial plan view of the balanced first stage valve of Figure 12 of the present invention; Figure 14 is a detailed view of the solenoid controlled valve of the present invention.

In the preferred form of the present invention the gas regulating apparatus is connected or connectable to a gas supply reservoir containing a gas. The apparatus of the present invention may be used for supplying gas for various gas requiring apparatus, however in particular this invention has applications for supplying a gaseous fuel to combustion engines which operate with a manifold vacuum. Most preferably the gas is CNG, however a person skill'ed in the art will appreciate that the gas regulating apparatus of the present invention will be suitable for use with other gases.

Hereinafter the operation and description of the gas regulating apparatus will be described in relation to combustion engines, but a person skilled in the art will realise the application to other gas requiring apparatus.

The gas regulating apparatus receives gas from the gas supply reservoir at a pressure Pr, and delivers the gas to an engine at a pressure Pd, as shown in Figure 7.

The regulator of the present invention is a two stage regulator which is capable of providing a constant pressure gas outlet (Pd) through a large range of gas pressure inputs (Pr). The desired pressure range is approximately from 200 bar down to less than 10 bar, however a person skilled in the art will appreciate that the apparatus can be adapted to be useful through different ranges of gas pressure input.

The gas from the gas supply reservoir at pressure Pr enters into the first chamber 2 through a inlet valve 1 as shown in Figure 1. The first chamber 2 is a 330311 chamber of variable volume, the volume being variable most preferably by a first chamber diaphragm 3. However, alternatively the volume in the first chamber 2 may be varied by use of a piston and cylinder arrangement, or any other suitable means. The flow of gas into the first chamber 2 is determined by the pressure P, inside the first chamber. The design of the inlet valve 1 is shown in more detail in Figure 4, and is shown in Figure 12 in the preferred form.

The inlet valve is a balanced first stage valve consisting of a shuttle 20 which is located inside of a shuttle chamber 22. The shuttle 20 is able to move axially between limits inside the shuttle chamber 22. The shuttle is connected by linkages 24 to the first chamber diaphragm 3 of the first stage chamber 2. The passageway has at least one outlet port 23 into the first chamber 2. The limits of movement of the shuttle 20 are such as to provide a restricted flow path of gas via said chamber shuttle 22 out through the outlet port 23 into the stage chamber 2 and a less restricting flow in at least one other position allowed by the shuttle 20 to provide a less restricted flow of gas through the chamber 22 out through the outlet ports 23 into the first chamber 2.

If the pressure inside the first chamber 2 increases, the volume in the first chamber 2 increases by the movement of the first chamber diaphragm 3. The linkages 24 are arranged such that when expansion of volume of the first chamber 2 occurs, the shuttle 20 is moved inside said shuttle passageway 22 so as to increase the restriction of flow of gas from the gas supply reservoir into the first chamber 2.

To compensate for variations in the gas supply reservoir pressure Pr, the shuttle 20 has been designed so as to operate independently from pressure Pr. This has been achieved by providing a gas pressure communication between the front pressure surface 31 of the shuttle 20 and the back surface 30 of the shuttle 20 as shown in Figure 4. In the most preferred form of the invention this communication has been achieved by providing a shuttle orifice 21 between the two volumes on either side of the shuttle, to ensure that gas of the same pressure as the gas supply reservoir pressure acts on both of the surfaces, 30 and 31. The surface area of the back surface 30 of the shuttle 20 is of a size so as to provide an equal and opposing force to the force resultant of pressure Pr on area 31. A.s the same gas pressure acting on surface 31 acts on surface 30, and as the areas of both surfaces are substantially the same, the force on 83 0311 - 10 the shuttle 20 due to the gas supply reservoir pressure Pr is effectively cancelled. Therefore the only other force acting or able to act on the shuttle 20 is as a result of the pressure of gas P, inside the first chamber 2. Figure 12 is a more detailed view of part of Figure 4 showing the balanced first stage valve in the most preferred form. The balanced first stage valve is connected to a gas supply reservoir or extension thereof using an appropriate connection means 50. This connection means 50 secures to the body of the gas regulating apparatus by for example a screw fitted type arrangement. Alternatively this may be secured thereto by a shrink fit or the like. A shim 51 is located about the perimeter of the connection means 50 at the interface to the gas regulating apparatus body. Most preferably the shim 51 is made of copper, however a person skilled in the art will realise that many other alternative materials may be utilised for such a shim. The nozzle 27 provides the seating against which the sealing pad 52 of the shuttle 20 is able to be seated. Most preferably the sealing pad is made from PETP and the shuttle is of a mild steel. Similarly the nozzle 27 is also a mild steel. 1 Gas in the space acting on the back surface 30 is contained therein by the use of o-rings 53, 54. Preferably the o-rings are made from nitrile. A person skilled in the art will however realise that other suitable means of sealing are available.

The linkages 24 which connect to the shuttle 20 and to the first chamber diaphragm 3 utilise needle roller bearings 55 and 56. A chain link 57 connects the shuttle 20 with the linkages 24. Figure 13 is a plan view of the chain link 27 illustrating it connected to the shuttle 20 and linkages 24. A person skilled in the art will realise the details of such a chain link and how it can be adapted for this present invention.

The inlet valve 1 may additionally include a means to bias to stabilise the shuttle 20. Such a means to bias, may for example be a spring 26 as shown in Figure 4 and is desirable to be included in the inlet valve 1 to stabilise the shuttle and prevent vibration and resonance of the shuttle. A person skilled in the art will be able to determine the spring constant desirable for the spring to have. Likewise there may also exist a means to bias the first chamber diaphragm 3 such as a spring 4, acting in a direction to decrease the volume in said first chamber 2. 330311 The pressure of the gas from the gas supply reservoir is reduced by the inlet valve 1 as it enters the first chamber 2.

The gas in the first chamber 2 at a pressure of P(, is able to flow into the speed governor which includes a first region 5 of a second chamber 5 and 7, through a first passageway 6, connecting the first and second chambers. The second chamber 5 and 7 consist of a first region 5 and a second region 7. The first and second region are most preferably partitioned by a means which is able to vary the volume in each of said first and second region. Illustrated in Figures 1-3, 6 and 11 the partitioning means is a diaphragm. However the variation in volume of the first region and second region 5 and 7 may be achieved by other means such as a piston cylinder arrangement as shown in Figure 8.

In the speed governor of Figure 11 the gas communication between the first region 5 and second region 7 is by means of a second outlet 28 (valved or non-valved) and through a passageway 8 which also is able to connect the second and third chambers. The variation in volume between the first region 5 and second region 7 is inversely proportional. As the volume in the first region 5 increases the volume in the second region 7 is proportionally decreased. The second diaphragm 9 is located between and separates the first region 5 from the second region 7, the total volume of the first region 5 and second region 7 remains constant. The variation in volume in each of the regions 5 and 7 is therefore dependent on the pressure differential between the gas pressure in the two regions 5 and 7.

An alternative arrangement to the use of a diaphragm 9 is the use of two piston cylinder arrangements, each of said first region 5 and said second region 7 having therein one cylinder and piston located therein. A connection between the two piston cylinder arrangements 43 and 44 in each of said first region 5 and said second region 7 ensures there is a communication of volume variation between each chamber. See Figure 8. Although in the preferred form the total volume in the first and second regions remains constant, from the arrangement of Figure 8, it will be realised that the use of pistons 43 and 44 of different diameters will result in a variation of the total volume of the first region 5 and second region 7. This may provide different advantages to the arrangement of the present invention. 330311 There is r.lso a first gas outlet 13 connecting the first region 5 to a third chamber 11. The first gas outlet 13 has a means of restricting the flow there through such as a first region valving element 19 which has a displacement communication with the second diaphragm 9.

The second region 7 has an outlet 12 connected to the third chamber 11 of variable volume as seen in Figure 1. The gas flow through said outlet 12 from said second region 7 is able to be restricted by a third chamber valving element 16. The flow through the outlet 12 from said second region 7 is restricted, proportional to the pressure in the third chamber 11. In the most preferred form of the invention this is achieved by means of a linkage arm 18 connected to a third chamber diaphragm 15. As the pressure in the third chamber 11 the volume therein increases as the third diaphragm 15 moves downwardly. This in turn pivots the linkage arm 18 about pivot 29 to restrict the flow in the outlet from said second chamber 12 by means of valve 16. As the pressure in the third chamber 11 decreases, the third chamber diaphragm 15 moves upwardly, pivoting the linkage arm 18 about pi\tot 29 to provide a less restricted flow of gas through the outlet from said second region 7 by means of valve 16. A person skilled in the art would realise that although the linkage ami 18, connected to the third chamber diaphragm and the pivot 29 is illustrated in a specific manner in the figures, many alternative means to achieve a flow restriction through the second region gas outlet 12, proportional to the pressure in the third chamber 11 exist.

As shown in Figures 2 and 3, the gas outlets 8, 28 and 12 have been arranged in an alternative manner, in which the outlets 8 and 12 have been combined. Both alternative arrangements allow the invention to be performed in a similar manner.

The gas flow leaves the third chamber 11 at a delivery pressure Pd.

At standstill when there is no demand for gas by the engine, the gas from the gas supply reservoir is able to flow through the inlet valve I into the first chamber 2 and through the first passageway 6 into the first region 5 of said second chamber 5 and 7. At this stage the gas is also able to flow through the non valved passageway gas outlet 28 and 8 into the second region 7. At standstill when there is no demand by the engine for gas, the pressure in the first chamber 2, first region 5, and second region 7 is 33031 equal because there is no engine manifold vacuum in the third chamber 11 and to the third chamber diaphragm 15 and hence the valve 16 remains closed.

When the engine is running at idle or low loads (as shown in Figure 2), the manifold vacuum of the engine causes a fourth diaphragm 14 to collapse thus setting the third chamber diaphragm 15 and linkage arm 18 free. As the vacuum increases in the third chamber 11, the volume therein is reduced by movement of the third chamber diaphragm 15 causing the linkage arm 18 to pivot about pivot 29 allowing gas to flow through the outlet 12. Because the demand for gas at idle and low loads is low, the outlet 28 is still capable of passing enough gas to supply the third chamber 11 and keep the pressure in the fust region 5 and second region 7 equal. The spring 10 will ensure that the first region valving element 19 remains seated, not allowing any flow of gas through the first outlet 13. At idle the restriction in flow through outlet 12 can be adjusted by means of an adjustment screw 17.

At medium and full load (as shown in Figure 3) the engine manifold vacuum on delivery pressure (Pd) is high. This causes the volume in the third chamber 11 to be even further reduced by movement of the third chamber diaphragm 15. This in turn reduces the restriction on flow of gas thorough the outlet 12 by the valve 16. At a high gas demand the outlet 28 is not capable of supplying enough gas to the second region 7 which is being demanded by the third chamber 11 and engine. This causes the gas pressure in the second region 7 to become less than the pressure in the first region 5. This reduction in pressure in the second region 7 causes the diaphragm 9 to lift the first region valving element valve 19 from its seat, allowing gas to enter the third chamber 11 through the first outlet 13.

The opening of the first outlet 13 at medium and full engine loads, ensures that sufficient gas is being supplied to the engine from the gas supply reservoir.

It is desirable for the performance of the engine that the regulated pressure Pj is as constant as possible. A conventional first stage valve is as shown in Figure 10.

In conventional first stage valves the regulated pressure P, acts on the diaphragm 32. Ideally the pressure P/ is only depending on the force required to vary the volume in the variable volume chamber, ie. the diaphragm force. The ratios of linkages and lever 33 are constant and do not change with the gas supply reservoir 330311 pressure Pr1. However as shown in Figure 10 there is also a force acting on the sealing pad area 341, and this force does vary with the gas supply reservoir pressure, Pr' and has therefore and effect on the regulated pressure P/. If the gas supply reservoir is full, the pressure Pn' is usually about 200 bar. The regulated pressure P,' has to be higher to counteract for this extra force than if the gas supply reservoir is nearly empty and the pressure therein is only about 15 bar. Figure 5 shows the theoretical variation of regulated pressure as a function of reservoir pressure, for a regulator as shown in Figure 10.

Figure 4 shows the working principle of the balance first stage valve, which overcomes the problem of having a valve, with a flow restriction dependent on gas supply reservoir pressure.

The shuttle 20 of the balanced first stage valve is linked mechanically to the diaphragm by linkages 24 ensuring the shuttle is in positive contact with the diaphragm.

Figure 6 illustrates the engine governor which is required to be present in the apparatus for engines which operate with a manifold vacuum, such as CNG engines, methanol engines and the like. j As explained before, under medium and full load conditions, the diaphragm 9 lifts the first region valving element 19 of its seat, allowing gas to pass through the first outlet 13. To govern the supply of gas to the engine so as to not oversupply the engine with gas the solenoid controlled valve 25 receives a signal from the ignition system, and opens up the governing passageway 35. This allows gas to enter the s xond region 7. This in turn allows the pressures in the first region 5 and second region 7 to equalize shutting off or restricting the first outlet 13 and hence restricting the supply of gas to the engine. The engine speed will drop, and at a certain speed the valve 25 will close the governing passage 35 again. The position of all diaphragms and valves in the apparatus will be an equilibrium at constant engine speeds, supplying a constant quantity of gas from the gas supply reservoir to the engine.

The solenoid controlled valve 25 may alternatively be a valve controlled by mechanical means as, for example, on certain types of diesel engines. • 330311 The restrictions of flow of gas through the gas regulating apparatus will be such as to maintain the engine at a stable engine speed. Figure 11 illustrates an engine speed governing apparatus which may have a different gas supply and first stage reduction to what was described earlier. Figure 14 illustrates the solenoid valve of the present invention in its preferred configuration. In the preferred form the solenoid valves screws into the body of the dual regulating assembly and engages therewith to align the governing passageways 35 of the first region and second region. The solenoid valve of Figure 14 is controlled electrically by an electrical connection 63' which connects to the coil of the solenoid 59'. The solenoid controls the valve stem 60' which in turn controls the flow of gas through the governing passageway 35' by means of control of the valve seats 40' and 61'. The valve spring 62 biases the valve seats to a closed condition, and the electrical current supplied to the solenoid regulates the flow through the governing passageway 35'.

The arrangement of the apparatus ensures that the supply of gas through the inlet valve and through the gas regulating apparatus is independent of gas input pressure and able to remain at a constant pressure over a large range of gas input pressures.1 The engine speed governor of Figure 11 may not necessarily be utilised in the gas regulating apparatus as described in Figure 1. The engine speed governor can be utilised in various other systems and a person skilled in the art will realise its application to other apparatus requiring a governing of gas supply. The engine speed governor of Figure 11 can be utilised independently in other applications, wherein the first gas outlet 13 and passageway 8 from the first and second region deliver gas to a gas demanding apparatus, and the flow of gas through passageway 8 is dependent on the third chamber valving element 16 who's position is dependent on the demand for gas of the gas requiring apparatus.

The gas supply regulator can be easily calibrated for various engine types and various engine demand ranges, by altering the configuration of the first gas outlet and first region valving element, see Figure 9.

Figure 9 illustrates the valving element and outlet, and shows that an insert 40 is easily placed inside the first outlet to reduce the outlet diameter to accommodate 33031 different levels of engine performance. The valving element must also be changed with the insert 40.

The non valved outlet from the first region of said second chamber, also needs to be of a known size. This outlet operates like an orifice, and is able to choke the flow of gas there through at specific flow velocities. This outlet 10 will be calibrated with the use of a choking screw 28 to restrict or open the flow through the passageway 8.

This invention can be used in any application where a pressure reduction of a constant nature is required, including engines with manifold pressure ie. super charged engines (not just manifold vacuum type engines). It also has non engine applications such as pressure regulation and diving apparatus and heat gas supply and the like.

The invention provides the possibility of having therein a governing system which is needed for diesel engines converted to operate using a gaseous fuel. > 330311

Claims (6)

WHAT WE CLAIM IS:
1. An engiiie speed governing apparatus for governing gas supply to apparatus requiring gas, said engine speed governing apparatus having or including: a governor chamber to receive gas flow from an inlet into a first region thereof partitioned from a second region thereof, said means partitioning (the "partition") the two regions of said governor chamber being moveable so as to affect the respective volumes of the regions of said second chamber, said first region including (a) a first gas outlet controlled by a first region valving-element carried by said partition and movable therewith from a closed seated condition to an open gas flow allowing condition and including (b) a second non valved gas outlet to said second region, said first gas outlet being to said apparatus requiring gas or some intermediate means, said second region gas outlet being to said apparatus requiring gas or some intermediate means, said second region including a second region gas outlet, (c) a third valve outlet to said second region, the flow of said gas through said third valve outlet controlled by a governing valve which is controlled by said apparatus requiring fuel, and wherein apparatus requiring gas has a low demand for said gas, the pressure at said first gas outlet and second region gas outlet is low, resulting in no flow through said first region valving element, allowing gas flow through said second non valved gas outlet into said second region and flow from said governor chamber into said apparatus requiring gas or some intermediate means, the pressure inside the first and second region of said governor chamber are equal, keeping said first region valving element closed, and wherein when apparatus requiring gas has a medium to high demand for gas, the pressure at said first gas outlet and second region gas outlel &t said; J<.' w< 3303 i demand, resulting in a reduction in flow restriction through said outlet-from said governor chamber, resulting in said flow through said second non valved gas outlet not able to meet the demand from said apparatus requiring gas, resulting in a reduction in pressure in said second region, relative to said first region, causing said partition to displace increasing the volume in said first region, and lifting said first region valving element from a closed seated condition to an open gas flow allowing condition, allowing gas flow from said first region to flow through said first gas outlet to said apparatus requiring gas or some intermediate means and wherein •when supply of gas through said engine speed governing apparatus or speed of the apparatus supplied gas exceeds a pre set limit, said governing valve will reduce the flow restriction through-said third valve outlet bringing pressures in said first and second regions to an equilibrium, reducing flow through said first outlet and to said apparatus requiring gas.
2. 2. An engine speed governing apparatus as claimed in claim 1, wherein said third valve outlet is a governing passageway present between said first region and said second region having said governing valve controlling gas flow there through such that when the gas flvw out of said engine speed governing apparatus reaches a limit, said governing valve opens to allow pressure equalisation in both regions.
3. 3. An engine speed governing apparatus as claimed in claim 1 or claim 2 wherein the governing valve includes an electronically controlled solenoid valve.
4. 4. An engine speed governing apparatus as claimed in any one of claims 1 to 3 wherein said means partitioning the two regions of said governor chamber is a diaphragm, having secured to a displacing region thereof said first region valving element and a means to bias said governor chamber diaphragm in a direction to encourage said first region valving element to remain in a closed seated condition.
5. 5. An engine speed governing apparatus as claimed in claim 4 wherein said means to bias said chamber diaphragm is a spring. [INTEUJW ij 3 0 APR $33 received. n 330311
6. 6. An engine speed governing apparatus as claimed in any previous claim, adapted for inclusion in a gas supply regulating apparatus for gas from a pressurised reservoir to apparatus requiring such a gas, said gas supply regulating apparatus having or including: (i) a first stage valve for an inlet from said reservoir having a valving element or assembly moveable from a closed seated condition to an open gas flow allowing condition, (ii) a first chamber to receive gas via said first stage valve, said first chamber being variable as to volume by first chamber diaphragm, piston or other periphery changing means, there being first stage valve linkage means between said first chamber diaphragm,-piston or other periphery changing means and the valving element or assembly of said first stage valve whereby (a) wherein the volume in said first chamber increases due to an increase in gas pressure therein, said valving element or assembly of said first stage valve increases the restriction of gas flow through said first ^tage valve into said first chamber, and whereby (b) wherein the volume in said first chamber decreases due to a decrease in gas pressure therein, said valving element or assembly of said first stage valve decreases the restriction of gas flow through said first stage valve into said first chamber, (iii) said engine speed governing apparatus which includes a governor chamber, (iv) a third chamber, said third chamber being variable as to volume by a third chamber diaphragm, piston or other periphery changing means, said third chamber able to receive gas flow from said first region of said governor chamber through the controlled said first gas outlet, and via an outlet from said governor chamber controlled by a third chamber valving element carried by said third chamber diaphragm, piston or periphery changing means, said third chamber including a second diaphragm laid an outlet to that apparatus requiring gas, INTELLECTUAL PROPERTY OFFICL and wherein apparatus requiring gas has no dema id for said^|l^ the pressire in said 3 0 APR 1993 RECEIVED 330311 third chamber is such that said second diaphragm or extension therefrom locates against said third chamber diaphragm, piston or periphery changing means and locates said third chamber valving element in a condition such that substantially no gas flows from said governor chamber into said third chamber via said second outlet region gas outlet from said governor chamber, and therefore no gas flow occurs through said first stage valve through said first and governor chamber into said third chamber, and wherein apparatus requiring gas has a low demand for said gas, the pressure in said third chamber is lower than at said no demand collapsing said second diaphragm and reducing the volume in said third chamber by movement of said third chamber diaphragm, piston or periphery changing means, resulting in a reduction in flow restriction through said third chamber valving element, allowing gas flow through said second non valved gas outlet into said second region and flow from said governor chamber into said third chamber through said outlet from said governor chamber, the pressure of said gas in said first chamber being lower than at said no demand reducing the restriction of flow through said first stage valve allowing said gas flow received through said first stage valve, through said first chamber, at said low demand for gas, the pressure inside said first and second region of said governor chamber are equal, keeping said first region valving closed, and wherein when apparatus requiring gas has a medium to high demand for gas, the pressure in said third chamber is lower than at said low demand, reducing the volume in said third chamber by movement of said third chamber diaphragm, position or periphery changing means, resulting in a fiirther reduction in flow restriction thiough said outlet from said governor chamber, resulting in said flow through said second non valved gas outlet unable to meet the demand from said apparatus requiring gas, resulting in a reduction in pressure in said second region, relative to said first region, causing said partition to displace increasing the volume in said first region, and lifting said first region valving element from a closed seated condition to an open gas flow allowing l intellectual property ; 1 OF N2 I 3 o trc ® j 330311 condition, allowing gas flow from said second region to flow through said first gas outlet into said third chamber from said reservoir. An engine speed governing apparatus substantially as herein described with reference to the accompanying drawings and/or examples. A method of operating engine speed governing apparatus substantially as herein described with reference to and illustrated by the accompanying drawings and/or examples. i END OF CLAIMS INTELLECTUAL PROPERTY OFFICE OF N2. 3 0 APR 1998 RECEIVED