The present invention relates to a valve plates with variable port delivery, in particular for supplying to a device the needed power supply in low and high gas pressure and at low and high temperature measured doses.

More in detail, the invention relates to a valve of the above kind in which, with the combination of fixed and mobile plates - each provided with a dispensing mouth and contained within the inner chamber of the valve body - the effect is obtained of changing the angular space through which it can be supplied, and permitted the discharge of any facility. This valve can be combined with other plate valves or other type of valves, forming combined valves. Examples of combination can be, for example but not limited to, one or more delivery valves and one or more exhaust valves.

In particular, these valves can be advantageously used for supplying a gas expander.

In this case, the valve can permit the supply of high- temperature compressed gas obtained from liquid gas and the consequent discharge of the exhausted expanded gas.

There are many known solutions for the power supply of facilities with measured quantities of gas. These solutions are very different and varied with each other as can be observed by examining what is available on the market and in the technical literature.

Said solutions, however, contribute to solve the problem of supplying controlled amount of gas only partially; in fact, all have drawbacks, to solve which technical solutions have been proposed, said solutions not allowing wide application range.

One of said systems, very used, is based on the metering valves comprising a mushroom shaped shutter, moved by the return springs. The opening of the valves is ensured by a suitable lever or by the direct action of a cam pushing the mushroom shaped shutter to control the metering valve toward the opening.

This action of the lever on the obturator generates a buckling action against the effect of the spring which tends to act in the closure direction of mushroom shaped shutter, as it occurs in the known tappet mechanisms known to those skilled in the art. This system is designated by the trade name of mushroom shaped shutter metering valves, driven in reciprocating motion by tappets with control cams. We take this valve as the reference valve, since the other known systems are in fact attributable to the same.

As already mentioned, in the prior art problems are found not completely solved by current solutions.

In particular, the known systems have a limitation of use in the presence of very high pressure and a temperature which can vary from that of the cryogenic type (for example -200°C, or even lower), up to high temperatures (for example + 400°C, or even higher).

Another limitation arises from the limited speed of intervention. This reduces their technical applicability, mainly because of the continuous reversals present in some known versions.

The inadequate reliability and constant behaviour over time cause important phenomena and not tolerable wearing and the need of frequent adjustments of the valves.

The adjustments operations are made even more necessary because of the considerable accelerations and inertial forces, caused by the inversion of the shutter, necessary to obtain the desired motion of opening and closing of the metering valve.

A system of this type, i.e. the one providing a mushroom- shaped shutter, is also characterized by the ability to operate only in the open state of the shutter or in the closed state of the shutter. This prevents the intermediate states between the two extremes "open" and "closed" states, if not employing complex levers systems, such as the "five-bar system", which does not always allow speed and reliability of the system as required in many technical applications.

A problem inherent in the system using the metering mushroom shaped valve in a reciprocating motion controlled by mushroom shaped tappets with control cams is the pressure of the fluid to be dosed. This system works well only with low pressures, for example atmospheric pressure, or slightly higher pressure. When high pressure is present, the system presents obvious difficulties of operation.

Also the high temperature of the fluid to be dosed is another problem encountered in the known technology. Under high cryogenic temperature known systems work in difficult conditions. Here there are needed technical solutions very difficult to apply and that otherwise fail to cover appropriate temperature ranges and related pressures.

Another limitation in known systems is the facility speed, which must be appropriate to that supply, and not vice versa, as necessary with the known systems. This strongly limits the performance and versatility of the facilities coupled to these valves.

The versatility is achieved even if a system is concerned that can dose the gas with advance and delays supply values adjustable under operating condition, something not possible with the current systems.

It may be made reference to other commercially available systems, but all have the same defects.

The solution according to the present invention has the object to solve, among others, the above mentioned problems.

The new solution substantially solves all the problems inherent in the prior art.

It is therefore specific object of the present invention a plate valve with variable port for the passage of a compressed fluid, said valve comprising an inner chamber having a bottom and being adapted to contain said compressed fluid, inside said inner chamber being provided an upper plate, a lower plate in correspondence with said bottom, and a compensation shaft suitable to connect the upper plate and the lower plate each other and suitable to balance forces generated by said compressed fluid, further, always within said inner chamber, being provided a dispensing plate provided between said lower plate and said bottom,

said lower plate, said dispensing plate and said bottom providing a respective dispensing opening, each dispensing opening having a respective dispensing angular amplitude,

said lower plate being configured in such a way as to be able to rotate with respect to its axis of at least one angular position,

said dispensing plate being configured so as to be adapted to carry out repeated rotations with respect to its own axis independently with respect to the rotation of said lower plate,

said valve being configured so that, during use, when said lower cap is in said at least one angular position, the dispensing opening of said lower plate at least partially overlaps with the dispensing opening of said bottom of the inner chamber, realizing a dispensing channel having a dispensing opening and so that, when said dispensing plate is rotating, to allow the passage of a fluid through said dispensing channel to the passage of the dispensing opening of the dispensing plate in correspondence of said dispensing channel.

Preferably, according to the invention, axes of said upper plate and of said lower plate coincide with the axis of said compensation shaft.

Always according to the invention, said compensation shaft is adapted to rotate with respect to its axis and in that the rotation of said compensation shaft determines the rotation of said lower plate with respect to its own axis.

Furthermore, according to the invention, said upper plate and/or said lower plate is rigidly connected to said compensation shaft.

Still according to the invention, said valve provides a control shaft acting on said dispensing plate to obtain said rotations.

Always according to the invention, said compensation shaft and said control shaft of the dispensing plate are concentrically placed one inside the other.

Furthermore, according to the invention, said valve provides a constant-velocity joint, able to allow small angular adjustments between the shaft compensation axis, the axis of the dispensing plate and the axis of the lower plate.

Further, according to the invention, said dispensing plate is configured in such a way as to be able to perform rotations with a continuous or reciprocating motion, according to one or another rotation direction.

Still according to the invention, said dispensing plate is configured in such a way as to be able to rotate in synchrony with a facility.

Further, according to the invention, each opening of said lower plate, of said dispensing plate and of said bottom of the inner chamber have equal dispensing angular amplitude.

Furthermore, according to the invention, said valve is suitable for feeding a compressed fluid contained within said inner chamber to a facility through said delivery channel.

Still according to the invention, said valve is suitable to discharge a fluid from a facility within said inner chamber through said dispensing channel.

Always according to the invention, said fluid is a liquid or a gas. Finally, according to the invention, said plates are of cylindrical or ovoid shape.

In a particularly preferred embodiment of the valve according to the invention, said plate is provided with a thickness, in such a way that the through hole of the plate of the plate itself contains the gas dose to be transmitted to the cylinder plunger.

Particularly, according to the invention, there are provided one or more recesses realized in a diaphragm, said diaphragm moving only according to the axis of rotation in order to balance the pressure in the lightening volume realized for lightening the plate, an anti-rotation button, without which the diaphragm would rotate and would not allow the synchronization of the filling position of the hole with the fixed position for supplying the facility, a contact and sealing spring , provided on the plate, which in turn is mounted with a thrust bearing and therefore does not rotate but compensates the axial thrust through the compensation shaft , said diaphragm not being able to rotate because of the anti-rotation button, but being able to move along the axis of rotation of the plates, said spring pushing the diaphragm against the lower disc producing the sealing effect.

The invention further concerns an expander comprising at least one valve according to the above, to supply or discharge high pressure and temperature gas obtained from liquid gas.

This new valve receives the gas under pressure in its internal chamber where they are placed, in the preferred embodiment, the upper plate at the top and the lower cap at the bottom.

The two plates, the upper and the lower, are connected by a compensating shaft. For convenience, the bottom and the top plates are mounted, in a preferred solution, in such a way that their axis coincides with that of the compensation shaft.

The upper plate also represents the upper cover of the internal chamber of the valve and compensates the thrust effect of the gas pressure on the lower plate with an equal and opposite thrust directed in the opposite direction with respect to the first one, via the compensation shaft.

The delivery port of the lower plate, the delivery port of the delivery plate and the delivery port on the bottom of the inner chamber, when they are in correspondence, realize the channel which provides the supply of the gas to the facility. In the lower plate, in the delivery plate and in the lower bottom of the inner chamber they are in fact realized the ports/spouts.

The compensation shaft, rotating about its axis, adjusts the position of the delivery port of the lower plate with respect to the delivery port of the lower bottom of the inner chamber.

When the delivery port of the lower plate is fully or partly superimposed to the port on the bottom of the inner chamber and the one present on the delivery plate passes in its movement in front of the delivery port of the bottom of the chamber, the passage of gas occurs, or in general, of the fluid that could be liquid, supplying the facility.

The ports may have an angular delivery dimension equal to each other, or each one may have its own angular amplitude, or two ports can have the same amplitude, while the third one a different amplitude. In a preferred application, but not limited to this, the delivery plate mechanically rotate connected to its own output shaft. The compensation shaft as the preferred solution rotates the lower plate.

The upper plate could also not be keyed onto the compensation shaft. That is, the upper plate may rotate or may not rotate with respect to the compensation shaft. In this case a solution, or other equivalent, may be an appropriate shoulder on the compensation shaft, which would allow in any case compensating the thrusts between the two plates: the lower and the upper plates, through the compensation shaft.

The new solution provides the possibility of a third plate, said delivery plate and advances and delays, provided under the lower retainer.

A delivery port is realized on the delivery plate, with an angular extension depending on the desired delivery behaviour.

By moving forward or backward the port of the lower plate with respect to the delivery port placed on the bottom of the inner chamber, it is obtained the variation of the delivery angle to the facilities.

The main advantage is that such adjustment is possible even during facility operation: the delivery plate is in fact controlled by its own independent axis offset from the compensation axis.

In a preferred embodiment the compensation shaft and the control shaft of delivery plate are concentrically placed one inside the other.

Not necessarily the compensation shaft must be rigidly connected to the lower plate. To resolve any possible contact problems between the lower plate and the delivery plate, it is possible using other systems such as, for example, a known mechanical connection, i.e. a constant velocity joint, or other known possible solutions, which allow small angular adjustments between the axis of the compensation shaft, the axis of the delivery plate and the axis of the lower plate.

If this lower plate is rotated so as to move for example angularly forward, the supply effect is prolungated, for an angular space longer, to supply power the compressed fluid (gas or liquid), to facilities, and vice versa.

On the basis of the combination of the positions of the lower plate of the delivery ports and of the delivery port provided on the bottom of the inner chamber, with the passage of the delivery port of the delivery plate, it is possible delivering the fluid (gas or liquid) for the desired delivery duration of fluid (gaseous or liquid) to the facility. Vice versa, the opposite effect is obtained, with the reduction of the angular space in which it occurs the delivering of the fluid, gas or liquid, to the facility.

The lower plate is provided with the possibility of angular movements and the delivery plate will have the speed of rotation necessary for delivery to the facility, with continuous or reciprocating motion. It is preferred the use of the continuous motion in the same direction to reduce the inertia effects.

Between the lower plate and the hollow groove of the delivery plate it is realized a phase shift angle effect, so that the two plate assembly, namely the lower plate and the adjustment plate, they behave as a plate but only with a useful angular amplitude variable, possibly in function of the shift phase angle imposed, during the facility operation.

The wished position is substantially obtained by angularly moving the lower plate positioned in correspondence of the delivery port from the inner chamber, towards the facility. Angularly moving in the motion direction the lower plate with respect to the neutral position - i.e., the position of the axis of symmetry of the groove provided on the lower plate coinciding with the axis of symmetry of the groove which constitutes the output from the internal chamber - then it is possible prolonging the increase of the angular space of the supplied compressed fluid (gas or liquid) to the facility. The forward displacement of the angle in the motion direction is said closing delay of closure of the delivery of compressed fluid (gas or liquid) to the facility. This angle is measured by geometric degrees.

Conversely, back movement of the angle with respect to the motion direction is said advance of closure of supply to the facility: this angle is measured by geometrical degrees. Similarly, these definitions identify the advance and delay angle to be used as controlled discharge of the plate valve according to the new invention.

It can then be said that this new invention, having a rotary delivery plate in synchrony with the facility and a lower plate remaining substantially stationary, but receiving to this end an advance or delay angle, is a plate valve with variable delivery port.

There is also the application of this plate valve with variable delivery port for discharging on a regular and controlled basis a fluid from a facility. The valve is similar to that described for the dosed supply of a fluid to a facility. It is only necessary varying the ports of the angular apertures of the delivery ports of the lower plate over the bottom of the lowering port of the inner chamber, with respect to the supply valve, dimensioning such angular apertures to the fluid flow rate that must pass through the valve.

The new solution finds advantageous general applications. A preferred application is for the supply and discharge of the gas, at high pressure and temperature, to supply an expander, where this gas is obtained from high pressure gasified liquid gas.

The present invention will be now described, for illustrative but not limitative purposes according to its preferred embodiments, with particular reference to the figures of the accompanying drawings, wherein:

figure 1 is a section view of a plate valve with the variable delivery plate port according to a preferred embodiment;

figures 1a, 1b and 1c, represent the development in plant of the circumferential sections of the two plates of the valve of figure 1 , respectively the lower and delivery plates, and the delivery port placed on the bottom of the inner chamber towards the user from the inner chamber; figures 2a, 2b, and 2c represent the start and end positions of the delivery valve of figure 1 , the lower plate moving forward according to the sense of rotation of the valve with respect to the position shown in figures 1a, 1b and 1c; figure 3 represents, in a further embodiment, a section view of a plate valve according to the invention;

figures 3a, 3b, 3c show an application of the valve according to the invention for dosing the supply of a compressed gas within the packaging of foods or other products to be packaged under a controlled atmosphere; figures 4a, 4b and 4c represent valves which are used in a volume three cylinders expander;

figures 5a, 5b, and 5c and 5d show views of a further embodiment of plate valve according to the invention.

Description of an example of a preferred application of the new invention to an expander supplied by high pressure and temperature compressed gas obtained from liquid gas.

In particular: the description concerns the application of the plate valve in a preferred embodiment with the delivery plate and with variable ports to a gas expander, said gas obtained from liquid gas in which the two valves are combined for convenience, a supply valve and a exhaust valve, in a single valve body 13.

More combined valves, a supply clave and a discharge valve, are used for supplying an expander realized in the example, the application of which can be extended to any number of groups, from only one to a plurality. In an exemplificative embodiment, it can be considered an expander formed by three alternative groups each comprised of piston and connecting rod to the crank shaft. Hub terminal exits from the crankshaft on mechanical energy is placed, recovered in the work process on the supply gas expander.

In figure 1 it is possible observing a section of a plate valve with the variable port delivery plate according to a preferred embodiment of the new invention. By the numerical reference 1 it is indicated the upper plate, connected by means of the compensation shaft 2 to the lower plate 3.

By the reference number 4 it is shown the delivery plate, by the reference number 5 it is indicated the bottom of the inner chamber 7.

By the reference number 6 it is shown the delivery port on the bottom of the delivery plate and the lower plate.

Figures 1a, 1b and 1c, represent the plant development of the circumferential sections 8 of the two plates, the lower 3 plate and the delivery plate 4, and the delivery ort 6 on the bottom 5 of the inner chamber towards the facility from the inner chamber 7. They are so realized to make understanding easier. In Figure 1 it is shown by reference number 13, the angular amplitude of one of the ports 6. Each one of the ports of the elements indicated as lower plate 3, delivery plate 4, and bottom of the inner chamber 5 will have its own delivery amplitude.

The preferred operating condition is that providing the delivery plate

4 in a synchronized movement with the facility, and the lower plate 3 provided with only small movements to change the position of the delivery ports 6 relative to one another as shown in figures 1a, 1 b and 1c, where the delivery port of the lower plate 3 is back from the port of the inner chamber of the valve 5.

Among the lower plate, the delivery plate and the delivery port of the bottom of the inner chamber 5 it is shown that, with the advancement of the overall movement effect represented by the "valve delivery port" the angular amplitude E01 is much less reduced at the maximum angular delivery potential amplitude E00 that would be obtained if the lower port of the delivery plate 3 was in position as the delivery port 6 of the bottom of the inner chamber of the valve 5. Between the figure 1a and figure 1c it is observed the angular amplitude E01 obtained leaving the lower plate in the position between the start delivery position and the final delivery position supply to facilities.

The comparison between the angular amplitude E01 and E00 shows in the example delivery port reduced during the operation of the invention.

Figures 1a, 1b and 1c show how to obtain the variations of angular delivery amplitude adjustable during operation of the new invention that uses the plates in the preferred cylindrical form.

Using other shapes for the inner chamber, the plates can have other shapes, for example ovoid or other, simply using devices known to experts in the field.

In this case, there are variations in speed of the delivery plate obtaining a cam effect. Thus, the slow passage of the delivery port of the lower plate 4 in front of the delivery port of the bottom of the lower plate 3 and the delivery port of the inner chamber 5. The application of other kinematic devices, e.g. but not imitatively, mechanics of ovoid gears, allows to obtain special effects to adjust the passage of the fluid through the new invention. Figures 2a, 2b, and 2c instead represent the delivery start and end positions, moving the bottom plate forward according to the direction of rotation of the valve with respect to the position shown in figures 1a, 1b and 1c, so as to place the port of the delivery plate 3 in a symmetrical position with respect to the width of the port 6 of the delivery port of the inner chamber of the valve 5. Amplitude of adjustment between the delivery start and delivery end is shown in figure 2c by E02.

Comparing the amplitude E01 and the amplitude E02, it is possible observing the adjustable variation that can be obtained by these variations to give suitable advances or delays of the lower plate. As a whole, it is obtained the effect of variable delivery angular amplitude to the facility, and then controlled and variable ports of the valve.

For the use of the valve as exhaust valve from the facility, angular openings 14 of the different ports are adapted angularly, each one with its own port generally indicated by reference number 6, but the principle of the advance and of the delay allows to have the variation of the exhaust port a that can be controlled.

Figure 3 shows how, in a preferred solution, it is obtained by the controlled thrust of the lower plate 3, the plate 3 is connected to the plate 1 by means of the compensation shaft 2, against the delivery plate 4.

The group comprised by the lower plate 3, the compensation shaft 2, and the upper plate 1 is made sliding axially, not carrying the group against a shoulder and leaving a space at the bottom and the possibility of vertical sliding as possibility given by the roller bearings 9 or equivalent, as a self-lubricating sintered bronze bushings or other suitable solutions known from the art, as seen, in the preferred form in figure 3.

Always in Figure 3, the spring 10 is loaded by means of the washer 11 of calibrated thickness or other equivalent means. In this way, the thrust of the spring is discharged onto the lower plate 3. And the plate 3 downloads in a controlled manner a thrust on the delivery plate 4.

In the preferred solution, to obtain the maximum flexibility, the delivery plate 4 assembly is controlled by a brushless motor 12 under frequency control mode.

This solution allows a choice of angle of advance and delay according to the needs and also with a valve function. The lower retainer group 3, the balance shaft 2 and the upper plate 1 is controlled by an analogue frequency control in the brushless motor 12. The two brushless motors are substantially equal as they are correlated with each other for the contacts and the actions and the corresponding reactions.

Even if the first motor, drives the lower retainer 3, retains the stationary lower plate 3 and the other related pieces and impresses only those movements of advance and delay on command. The delivery plate 4 instead rotates according to the needing of the technology program operating the facility by providing a reciprocating motion to the same plate, or, in the preferred embodiment, continuously in the movement direction.

In the preferred embodiment, toothed belts and related pulleys are used for transmitting the control from the motors to the motion axes of the plates. Toothed belts can also be replaced by equivalent devices such as chains or toothed wheels or other types of known transmission means.

A mechanical version equivalent to the use of engines, and which therefore may be an alternative to one or more, or all, the brushless motors, is that of to transmitting the motion to the control of the shaft control pulleys moving the delivery plate 4 using a simple transmission of the main angle. Corner transmission taking the motion from the facility transmitted directly to the valve. Instead, the control of the lower plate 3 assembly, the compensation shaft 2 and the upper plate 1 is controlled by a control changing the position of the assembly also with a direct control, when necessary, to modify advances and delays. Maybe also simply with the action of a lever mechanism.

This plate valves, with the delivery having variable port as explained can be advantageously used not only for supplying the facilities with gas, but also for:

- allowing the discharge of the exhaust gas by the facility itself;

- regulating the supply of liquid and the discharge of liquid;

- combinations of the various applications, supply and exhaust; - either in supply and exhaust mode.

In all cases, the combination of fixed and movable plates, each provided with a delivery port, each one having its angular amplitude or amplitude equal to the others, contained in the inner chamber of the valve body, and the bottom of the delivery port of the inner chamber allows to change the overall angular space along which it can supply a facility or allow the unloading by the facility with the same supply valve performing both functions. This valve can also be combined with other plates or of other type of valves, thus forming valves combined as for example of supply valve combined with the exhaust valve. Examples of combination can be, for example, but not limited to, one or more delivery valves and one or more exhaust valves: all plate valves or at least one plate valve and one other of another type.

By way of example it is presented a preferred application to a facility represented by an expander formed by a system including one or more alternative systems, each one of the plunger and connecting rods and crankshaft type, combined with one another, the movement of which allows the expansion of the gas and the collection of mechanical energy of the expander to a terminal hub and as result of the expansion of the supply gas. The expander can also be of the rotary volumetric type or a flow expander, as one skilled in the art can do receiving the teaching of this invention.

Figure 4a, figure 4b and figure 4c represent for explicative reasons, but not limited to this, a three cylinders volume expander (the volumetric expander is not drawn because known) where from figure 4a it can be observed that a supply valve and a discharge valve can be combined in a preferred embodiment.

This valve is in turn combined putting three other equal side by side as shown by way of example in figure 4a, figure 4b and figure 4c. Said valves could also be combined so as to have a single valve body 13 and the same body common to the three individual valves, combined as it is observed in figures 4a, 4b and 4c. Then it can be observed how the kinematic links are combined.

For a rotary volumetric system, the combination of the valves will be different, but one skilled in the field, once chosen the type of rotary expander, will receive the teaching and will be able to combine the valves as required by the system. All included within the scope of the invention.

In the example of figure 4a, figure 4b, figure 4c, brushless motors are used to have a very flexible application and that can be also inserted in a fully automated system. The use of the mechanical system as shown for single valve can also be applied with a facility including only one element, but also more elements combined with each other.

Obviously the one skilled in the art will be able to modify the facility, the method and to application of the new invention with respect to the expander described above, in order to meet contingent and specific requirements, all however included within the scope of the invention as defined by the claims.

Coming now to make reference to figures 5a - 5d, there is shown a further embodiment of plate valve according to the invention, in which the same numerical references are used for identical or similar parts.

In this particular embodiment of the valve according to the invention, wherein the amount of supply or exhaust gas is dosed with extreme precision. This embodiment is used in applications where a millesimal measuring supply or exhaust of a certain amount of gas is required.

In this case, with an adequate thickness of the plate 3, the supply port 6 of the plate 3 itself contains the gas dose to be transmitted to the cylinder piston.

The effect is obtained by making the supply port 6 filling, so that, as a result of its rotation, when the port 6 is placed in the supply position of the cylinder piston, it transmits only the part of the gas contained within volume of the port 6 of the plate 3 (less the residual volume remaining in the port 6 of the plate 3 and which is taken into account in the calculation of the volume).

In figures 5a - 5d, by the reference number 7 they are indicated one or more hollow grooves realized in the diaphragm, so that it cannot rotate. This diaphragm can move only according to the axis of rotation in order to balance the pressure in the lightening volume realized for lightening of the plate 3.

It is also shown an anti-rotation button 8, without which the diaphragm would rotate and would not allow the synchronization of the supply port 6 position with the fixed supply position of the facility.

A contact and sealing spring 9 is provided on the plate 1 , which in turn is mounted with a thrust bearing and therefore does not rotate but still compensates the axial thrust through the compensation shaft 2.

The diaphragm 10, previously mentioned, does not rotate because of the anti-rotation button 8, but can move along the rotation axis of the plates. The spring 9 pushes the diaphragm 10 against the lower plate, realizing the sealing effect. The contact surfaces, in the preferred embodiment, are of different hardness and chosen so as to obtain self- lubrication of the contact surfaces. With this solution it is achieved the additional advantage that it can be dosed more accurately the amount of gas supplied to the cylinder and piston assembly especially in applications for gas-precision dosages.

The present invention has been described, for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that variations and/or modifications can be made by one skilled in the art, without departing from the relative scope, as defined in the enclosed claims.