Flow controlled piston valve

Piston valve (10) with a hollow housing (13), an inlet (11) and an outlet (12) communicating with the inlet only through the piston valve (10), and a pushbutton (27) that can be moved in and out direction of the housing. A control valve (30) is also arranged in the inner cavity of the housing (13) spaced axially from the valve seat (14), and the opening and closing of the control valve (30) is controlled by the position of the pushbutton.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention is a national stage entry of international application no. PCT/HU2019/050041, filed on Sep. 10, 2019, which claims priority to Hungarian patent application no. P1900114, filed on Apr. 5, 2019.

Not applicable.

NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

REFERENCE TO A SEQUENCE LISTING

Not applicable.

Not applicable.

BACKGROUND OF THE INVENTION

The invention relates to a piston valve that has a hollow housing, an inlet provided in the housing, an outlet communicating with the inlet only through the piston valve, and a pushbutton that can be moved in and out direction compared to the housing, wherein the pushed in and pulled out states of the pushbutton set the closed, respectively open states of the piston valve, which comprises furthermore a valve piston arranged in the hollow interior of the housing and guided for displacement along the longitudinal axis, a valve seat provided on an element extending normal to said longitudinal axis, wherein in an extreme position of the valve piston when it is pressed to the valve seat the piston valve is in closed state.

Valves operated by pressure are required in several applications, e.g. when a water flow should be opened or closed easily and quickly and there is no need for adjusting the flow rate. The operation of widely used taps with rotating arm or having only a single arm can be too complex in given applications or in a slippery area where it is not safe or the opening and closing requires certain degree of skill. In other fields, the large size of such taps excludes their use.

Several solutions have been provided for controlling the opening/closing by a pushbutton. One such solution is represented, for example, by DE 10 2009 008 194, in which it can provide, in addition to opening and closing, a branching of an inlet towards a plurality of outlets. In this solution, by pushing a pushbutton, the angular displacement of a ceramic body in several steps can be caused. The ceramic body has a plurality of openings, and under or above the ceramic body there is another different ceramic body also with openings. Based on the relative positions of such openings, the water flow will be opened or closed or led to different outlets.

A fluid opening and closing and branching off by means of the turning of a ceramic disc can be learned in DE 101 37611. The turning takes place in a similar way as the opening and closing of ball point pens, wherein the turning of a shaped element results in the elevated or sunken position of the writing rod of the ball point pen.

In DE2229612, a flushing valve is described in which the pressing of a pushbutton causes the outflow of a predetermined amount of water, wherein there is a main piston valve and a control piston valve arranged so that the time of the flow state is defined by the time required for a bypass flow path to equalize the pressure differences acting on the main piston valve to push the piston of the control valve to close the flow of water. That design cannot be used for a two-state operation in which the water flow is defined by the on or off state of the pushbutton.

In case of classic valves, a piston can be moved above a valve seat in an axial direction and in a pushed state the flow path is broken and in a pulled state the path is open. This operation does not allow that the change from the closed state to the open state and from the open state to the closed state occur by the repeated pushing of the same handling means.

A drawback of mechanically operated piston valves lies in that the transient processes of the closing and opening operations are determined by how handling takes place, and the force required for the operation is also not independent from the pressure of the fluid.

Furthermore, it is also not indifferent that a handling device, e.g. a pushbutton, can perform only the function of opening and closing, without a further constructional design that allows, by utilizing certain further parameters thereof (e.g. by its turning), performance of further important functions (e.g. the mixing of cold and hot water, or the interconnection of an inlet with a plurality of outlets, or the combination of such functions).

In certain applications it may be required that the opening and closing of a flow path takes place with a certain delay compared to the activation of a handling device.

BRIEF SUMMARY OF THE INVENTION

The object of the invention is to provide a piston valve which can enable the control associated with the valve function with the repeated pushing of a pushbutton, and in which the pushbutton is not connected with direct mechanical connection with the piston that directly operates the valve, thus the user cannot influence the transient processes of the opening and closing steps.

A further task of the invention is to ensure that parameters of the handling device of the piston valve (e.g. its turning) other than the pushing be available for performing other functions without influencing the performance of the main function.

A still further task is to provide a piston valve in which the opening and/or closing of the valve takes place with a delay compared to the operation of the pushbutton.

For solving these tasks, a piston valve has been provided comprising a hollow housing with a longitudinal axis, an inlet provided in the housing, an outlet communicating with the inlet only through the piston valve, and a pushbutton that can be moved in and out direction compared to the housing, wherein the pushed in and pulled out states of the pushbutton set the closed respectively open states of the piston valve that comprises furthermore a valve piston with two opposite end faces and arranged in the hollow interior of the housing and guided for displacement along the longitudinal axis, a valve seat provided on an element extending normal to the longitudinal axis, wherein in an extreme position of the valve piston when it is pressed to the valve seat the piston valve is in closed state, and the inlet is led through a passage into the inner cavity of the housing so that in the closed state of the valve piston a lower portion of the valve piston closes said passage, and according to the invention a control valve is arranged in the inner cavity of the housing in a predetermined axial distance from the valve seat and the opening and closing of the control valve is controlled by the position of the pushbutton, and in the interior of the housing between the valve piston and the control valve and intermediate space is formed and the size of the intermediate space depends on the momentary position of the valve piston, and a shunt flow passage is provided between the two end faces of the valve piston providing a small fluid flow, wherein the cross section of the shunt passage is smaller than the flow cross section of the control valve when being in open state, and above the control valve the inner cavity of the housing defines an upper space between the control valve and the pushbutton, a spring is arranged in the upper space that presses the control valve to its closing direction, and in the intermediate space a further spring is arranged that presses the valve piston to take a closed position, and the housing comprises a passage that interconnects the interior space under the valve seat with the upper space, and between the pushbutton and the valve piston there is no mechanical connection, and the pushbutton controls the valve piston only by utilizing the established fluid flow and the associated pressure patterns.

In a preferred embodiment of the piston valve, a radial groove is provided on the outer surface of the valve piston, and a ring made of a resilient material is inserted in the groove, wherein the width and/or depth of the groove is greater than a size of the ring and the so resulting gap constitutes the shunt passage or at least a portion thereof.

In an alternative or complementary embodiment, along the outer mantle of the valve piston at least one axial cut is provided, and this constitutes said shunt passage or at least a portion thereof.

In a further preferred embodiment, a closing body is fixed to the upper part of the housing, and the control valve has a valve seat made in the lower end of the closing body that has a hollow interior constituting said upper space, and the pushbutton is guided and sealed in the closing body, and the control valve is operated by a shaft lead through the upper space and connected to the pushbutton, and the spring that provides bias to the control valve is arranged around the shaft.

In this case, it is preferred if the valve piston comprises an inner nest receiving and supporting an end of the spring, an outer ring is arranged around the inner nest having an upper face, and in the fully open state of the piston valve this upper face abuts the lower end of the closing body (23).

Further function can be realized if the closing body is fixed in the housing in a sealed way which allows its turning around the longitudinal axis.

Further advantages can be attained if the opening and closing of the piston valve is delayed after pushing the pushbutton by means of adjusting the cross section of said shunt passages.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows the sectional elevation view of a piston valve10controlled and designed according to the invention. The piston valve10has inlet11and outlet12. The inlet11is connected by means of a connection not shown in the drawing to a source of mixed water under pressure, wherein the temperature of the mixed water is determined by the flow rates of the constituting cold and hot water. The outlet12can be connected, for example, to a shower head, also not shown in the drawing, which is under normal atmospheric pressure.FIG. 1shows the piston valve10in closed state when there is no fluid passage between the inlet11and the outlet12.

The piston valve10has a housing13that has a cylindrical hollow body with a valve seat14at its lower portion constituted by an asymmetrically designed separation member extending normal to longitudinal axis15of the housing13, and the separation member has a central opening that communicates with the outlet12. In the interior of the housing13, at the left side in the view ofFIG. 1, a vertical passage16is provided which ends above the valve seat14and it communicates with the inlet11.

In the interior cavity of the housing13in the space above the valve seat14a partially closed valve piston17is arranged that has a bottom part formed as a cylindrical duct on which a groove is provided for receiving a sealing ring18. The valve piston17has a wider cylindrical upper body portion on which an outwardly open groove19is provided in which an O-ring20is inserted with a diameter smaller than the size of the groove19, whereby the valve piston17does not provide a sealed separation between the spaces under and above it. It is noted that the design of the valve piston17is illustrated in detail inFIGS. 5a, 5band 5cin which it can be observed that in addition to the imperfectly closing ring20a pair of axial cuts21,22are provided in an outer mantle44of the valve piston17that constitute respective passages with small cross section that act as shunt passages8between the two end surfaces of the valve piston17. In connection with the valve piston17, the attribute, “partially closed,” designates that the two spaces separated thereby are not hermetically closed from each other, but there is a predetermined degree of fluid passage between them.

Reference is made again toFIG. 1, which shows a closing body23is attached to the upper side of the housing13that has an outer diameter substantially equal to the diameter of the housing13, and the closing body23is designed symmetrically to the longitudinal axis15and extends into the inner cavity of the housing13following a stepwise narrowing section. The closing body23also has a hollow interior with a lower end24that hosts respective sunken nests40and42both under and above the lower end24. Into the lower nest40the upper end of a spring25is inserted that provides a bias to the valve piston17, and into the upper nest42the lower end of a spring26is arranged that provides a bias for a pushbutton27. The pushbutton27is inserted into the central opening of the closing body23and it is guided for axial displacement along the longitudinal axis15. In the central lower portion of the pushbutton27a threaded shaft28is fixed. The lower end of the shaft28is slightly wider and has an outwardly open circular groove into which a sealing ring29is arranged. At the lower end24of the closing body23a recess is formed with conical lower outer surface. The shaft28together with the sealing ring29constitutes a control valve30and its axial displacement is enabled by the sealed guiding of the pushbutton27in the inner bore of the housing13.

The spring26is arranged between the inner surface of the pushbutton27and the central part of the upper surface of the lower end24of the closing body23and presses the pushbutton27in upward direction i.e. outward of the housing13.

The biasing spring25is arranged between the lower nest40of the end24and the valve piston17and presses the valve piston17in lower direction towards the valve seat14. The lower end of the spring25is kept by a nest48formed in the upper face of the valve piston. The nest48is surrounded by a cylindrical ring50which has an upper face52that forms the upper face of the valve piston17.

In the wall of the housing13shown at the right side ofFIG. 1of the drawing, a vertical passage31is provided and its lower end communicates with the inner cavity of the housing13under the valve seat14and in this way with the outlet12, and its upper end communicates with an upper space32defined between the lower surface of the pushbutton27and the lower end24of the closing body23. The diameter of the shaft28is slightly smaller than an axial bore33provided in the central part of the lower end24of the closing body23, therefore in the pushed state of the pushbutton27the aforementioned upper space32communicates with an intermediate space34formed between the lower end24of the closing body23and the valve piston17.

The operation of the piston valve according to the invention is as follows.

In the position shown inFIG. 1the piston valve17is pressed by the biasing spring25to the valve seat14, and the valve is sealed by the sealing ring18. The pressure in the intermediate space34is the same pressure what is present at the inlet11which is higher than the atmospheric one. In the upper space32there is only atmospheric pressure because now the control valve30is in closed state (the pushbutton27is in its upper position), i.e. the pressures in the intermediate space34differs from that prevailing in the upper space32. The atmospheric pressure in the upper space32is caused through the passage31because at the lower end thereof the communication with the outlet12ensures this atmospheric pressure. In this position the overpressure prevailing in the intermediate space34acts on the lowermost surface of the shaft28, whereby this pressure is higher than the bias provided on the control valve30by the spring26, and the control valve30is pressed to its own valve seat46and remains closed. The same overpressure also acts on the upper end of the valve piston17and in addition to the pressure provided by the spring25presses the same to its own valve seat14.

Reference is made now toFIG. 2in which the pushbutton27is shown in pressed position, i.e. its upper end falls in the upper plane of the closing body23and the control valve30is in open state because the sealing ring29is moved away from its valve seat with inclined surface. When the control valve30is opened, a fluid passage opens between the intermediate space34and the upper space32through the axial bore33and owing to the fact that in the upper space32there is only a low (atmospheric) pressure, the fluid with overpressure will flow through the open bore33in the upper space32and the pressure in the intermediate space34will decrease. The pressure difference between the lower and upper surfaces of the valve piston17will push and move the valve piston17in upward direction along the longitudinal axis15against the biasing force of the spring25, whereby under the valve piston17a passage will open for the mixed water towards the outlet12, and that pressure will present itself through the passage31also in the upper space32.

As a consequence of the described pressure distribution the valve piston17will move in upward direction till its abutment, which state is shown inFIG. 3. The upper face of the valve piston17, which is formed by the previously mentioned cylindrical ring50, abuts the lower surface of the lower end24of the closing body23and the volume of the intermediate space34decreases to minimum. The shunt path between the lower and upper faces of the valve piston17gets substantially decreased. The pressure of the fluid flowing from the inlet11presses the valve piston17in upper direction against the biasing force of the spring25and a free flow path is provided between the inlet11and the outlet12. The pressure in the upper space32corresponds substantially to that at the outlet12. The pressure difference between the two opposite faces of the valve piston17keeps it in the open position shown inFIG. 3.

This free flow path can be closed by the lifting of the pushbutton27. Then the control valve30takes the closed position shown inFIG. 4. By the closure of the control valve30the flow path between the upper space32and the intermediate space34(decreased to minimum) above the valve piston17gets broken. The increased pressure under the valve piston17forces the fluid to flow into the intermediate space34, whereby the pressure difference between the upper and lower faces of the valve piston17decreases to zero and the biasing force of the spring25pushes the valve piston17in downward direction until it reaches to position shown inFIG. 1. Then the fluid path gets broken between the inlet11and the outlet12and the valve closes. In the upper space32again the atmospheric pressure will prevail through the passage31.

At this design if the pressure at the inlet11disappears due to any reason, the spring25will push the valve piston17into the lowermost position at which the valve gets closed, and the spring26will similarly close the control valve30. In this way if in the water supply system any problem takes place and the overpressure disappears, the fully closed state will be automatically taken, and when the pressure returns, flow can commence only after the pushbutton27has been intentionally pushed again.

A characteristic property of the solution according to the invention lies in that there is no kind of direct mechanical connection between the pushbutton27with the valve piston17which opens and closes the main flow path, because the valve piston17is moved exclusively by the flow and pressure distribution pattern provided together with the effects of the biasing springs25,26. The speed of the opening and closing transient processes can be controlled in a fine way by the design of the shunt passages8, i.e. the decreased outer sealing of the valve piston17and the size of the cuts21,22and the cross section and length of the passage31.

A specialty of this solution lies in that the cross section of the flow path between the two opposite faces of the valve piston17is determined first by the cross section of the cut21,22and the play between the groove19and the ring20. If the cross section of these passages is changed, i.e. decreased, then fluid can flow only slower between the two opposite faces and the previously mentioned pressure equalization requires a longer time which causes delay in the closing and opening of the valve. There can be field of application in which the start of water flow occurs only with a delay after the pushbutton27has been pressed. The extent of the delay can be adjusted by the change of the aforementioned cross sections of the shunt paths.

A further characteristic of the embodiment described lies in that the operation of the valve does not require the turning of either the pushbutton27or of the closing body23. Therefore, the relative angular position of these elements can be fixed, which provides room and possibility for further control functions. The closing body23is therefore arranged in a sealed way in the housing13but it can be turned around the axis15. Of course, the possibility of the turning is also provided if the relative angular position of the housing13and the closing body23is fixed, and in that case the housing13and the closing body23can be turned together.