A VALVE DEVICE

Abstract: A valve device is intended to communicate with a space (8) for pressurized fluid through a first connection line (6) and allow outflow of pressurized fluid and communication with a pressurized-fluid source, respectively through a second connection line (5). The valve device is arranged to maintain a residual pressure in the pressurized-fluid space but allow supply of pressurized fluid to the space upon application of pressure on the second connection line. The valve device comprises two non-return valve units (9, 10), one of which closes against pressurized-fluid outflow from the space when the pressure therein falls below a certain level whereas the other opens upon said application of pressure on the second connection line. The non-return valve units are located in two different chambers (11, 12) in a body (3) of the valve device. Each of these chambers is accessible from the outside of the body through an opening (13 and 14 respectively) of its own separated from the outer orifices of the connection lines in order to insert and remove, respectively, and possibly also adjust the valve units or parts thereof through theses openings.

Description: A valve device. ■ TECHNICAL FIELD OF THE INVENTION AND PRIOR ART The invention relates to a valve device according to the preamble of claim 1. Such valve devices are known through DE-OS 2 131 805 and 2 261 762. The first one of these publications describes a valve device in which the two valve units are inserted in a common chamber, the opening of which also forms the fluid outflow opening. This means that it for maintenance, change or adjustment of the valve units will be necessary to carry out a disassembly work in a comparatively large scale, since mostly further components are connected to the outflow opening. As a consequence of this it is necessary to cause an interuption in the use of the valve device and the devices connected thereto. This may in the practice involve considerable disadvantages. Furthermore, the valve units according to the German publi¬ cation are comparatively complicated and they are more exactly integrally built up in such a way that the valve seat for the mobile valve member of the second valve unit is made on the mobile valve member of the first valve unit. By that the manufacturing costs are also getting important. Even though the closing pressure of the first valve unit may be adjusted (however, after considerable disassembling work through the outflow line) in such a way as described in the German publi¬ cation, -it would be necessary to completely remove the valve units from the body of the valve device, if it would be requi¬ red to adjust the opening pressure of the second valve unit. A second embodiment of the valve device based on valve members in the form of elastic discs is described in DE-OS 2 261 762. Even though this valve device is constructively more simple it has the same disadvantages as the one according to the first mentioned German publication with respect to the disassembling work required in connection with maintenance etc, and thereto a disadvantage of the demand to a change of the valve means for variation of a closing and opening pressure is added. SUMMARY OF THE INVENTION The object of the present invention is to reduce the disadvan¬ tages mentioned above and accordingly obtain a valve device, which on one hand is of a simple construction and on the other requires a minimum of work in maintenance and disassembling of the valve units, as well as adjustment should be very easy to carry out when the valve units are made adjustable. This object is obtained by the subject matter defined in the characterizing part of claim 1. By that the valve units will be easy to get access to from the outside of the valve body through the openings of the chambers without the necessity to dissembling components attached to the valve device, so that they communicate with the connection lines. The valve device does also become extremely simple, since the valve units are in a constructive way independently of each other located in their chambers. Furthermore, by using the characteristics according to the dependent claims 2-10 further simplifications are obtained with respects to the flow paths of the valve device and accordingly with respect to the very manufacturing of the device. BRIEF DESCRIPTION OF THE DRAWINGS With reference to the appended drawings, below follows a specific description of embodiments according to the invention cited as examples. In the drawings: Fig 1 is a partially longitudinal section through a first embodiment of the valve device and fig 2 is a similar section through a second embodiment. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT (FIG 1) The valve device according to the invention will below first be described as used at a gas bottle 1 schematically indicated. The valve device, which is generally indicated by 2, has a valve body 3 made of one piece ' . This comprises at one of its ends connection means 4, here in the form of a male threaded shaft, for connection to corresponding connection means, e.g. a female threaded bore in the gas bottle. At its other end the body 3 has a bore 5, which is provided with an internal thread for connection to arbitrary components in the form of lines, valves etc. Generally a male threaded sleave or the like will serve as means for connection to the threaded bore 5. The bore 5 will therefore in the practice constitute a connection line which has an outer orifice 23 at the outside of the body 3. The valve device is intended to communicate with the interior of the gas bottle through a connection line 6 with an outer orifice 24 at the outside of the body 3 and allow gas outflow from the interior of the gas bottle schematically indicated by 8 through the connection line 5 and a line portion 7. In a way that will be described more in detail hereafter, the connection line 5, 7 may be brought into communication with the gas source for filling a gas bottle. The connection lines 5, 6 and their orifices may of course be differently shaped, if connection means of another type has to be connected thereto. The valve device 2 is conceived to maintain a residual pressure in the interior 8 of the gas bottle but allow supply of pressurized fluid to this interior when pressure is applied on the lines 5, 7. More in detail the valve device comprises two non-return valve units 9 and 10, one 9 of which closes against gas outflow from the gas bottle when the pressure falls below a certain level whereas the other 10 is intended to open upon application of a sufficient pressure on the line 5, 7. In other words the valve unit 9 guarantees that the pressure in the gas bottle only sinks to a predetermined value at which the valve 9 closes. By that there is no risk of return of impurities, condensate or undesired gas from the environment. By means of the valve unit 10 the gas bottle may be filled as soon as a sufficiently high pressure is applied in the line 5, 7. No complex filling devices are required. Besides the valve device 2 according to the invention a cut-off valve will of course be required. Such a valve may be arranged either between the gas bottle 1 and the valve device 2 or be connected through the connection means or bore 5 of the latter, i.e. in the gas outflow direction downstream of the valve device 2. The non-return valve units 9 and 10 are located in two diffe¬ rent chambers 11 and 12 in the body 3 of the valve device, and each of these chambers is accessible from the outside of the body through an opening 13 and 14, respectively, of their own separated from the outer orifices 23, 24 of the connection lines 5, 6 in order to insert and remove, respectively, and possibly also adjust the valve units or parts thereof through these openings. The openings 13, 14 of the chambers emerge on the outer side of the body 3 of the valve device in substantially opposite directions. . The .connection lines 5, 6 emerge at two opposite ends of the valve device body and the openings 13, 14 of the chambers emerge on the outer side of the body substantially perpendi¬ cularly to the emerging direction of the connection lines 5, 6. The chambers 11, 12 are directed, so that their longitudinal directions are substantially perpendicular to the main flow direction through the valve device body and in the example substantially perpendicular to the longitudinal direction of the valve device body. The valve device comprises two flow paths, to which the connection lines are common. The two chambers 11, 12 for the valve units both form parts of each of these two flow paths. The connection line 6 communicates with a chamber 12 of the valve unit 10, which communicates with the chamber 11 of the valve unit 9 through a line portion 15, said valve unit 9 being arranged to close and open, respectively, the communication between this line portion 15 and its chamber 11. The connection line 5 communicates with the chamber 11 of the valve unit 9 through the line portion 7 and this chamber communicates with the chamber 12 of the valve unit 10 through a second line portion 16, said valve unit 10 being arranged to close and open, respectively, the communication between a second line portion 16 and its chamber 12. Accordingly, the first flow path is formed by the connection line 6, the chamber 12, the line portion 15, the chamber 11 and the connection line 5, 7, whereas the second flow path is formed by the connection line 5, 7, the chamber 11, the line portion 16, the chamber 12 and the connection lines 6. In the first flow path the valve unit 9 is active for closing and opening, respectively, whereas the second valve unit 10 is completely passive, so that there is always a free flow through this chamber 12. In the second flow path the valve unit 10 is active or closing and opening, respectively, whereas the valve unit 9 is completely passive and does accordingly always allow fluid flow through its chamber 11. The chambers 11 and 12 are substantially parallel to each other but mutually displaced perpendicularly to their longitudinal axis in the way illustrated in fig 1. In a region in the central part of the valve device the chambers extend past each other, so that they overlap each other, although they are located at a mutual distance. The connection line 6 and the line portion 15 are formed by a rectilinearly extending channel, preferably achieved by a bore, which traverses the chamber 12. The line portion 7 and the line portion 16 are formed by a rectilinearly extending second channel, preferably here also a bore, which traverses the chamber 11 and emerges into the bore 5. If instead of an in¬ ternal threaded hole 5 a male threaded connection portion would be provided the line 7 could extend all the way to its extre¬ mity and then form the orifice 23. The chambers 11 and 12 may also advantageously be achieved by drilling. Each of the valve units 9 and 10 comprises in the bottom region of the chamber 11 and 12, respectively, a valve seat coopera¬ ting with a mobile valve member 18, which by means of a spring 19 housed within the chamber in question is affected to coope¬ rate with the valve seat 17 in a closing manner. The valve seat 17 may be made in one and the same piece with the valve device body 3 and in this case it will be suitable to carry out an opening 20 in the seat by drilling, but the valve seat 17 may also consists of a separate member, for instance a disc-like one, inserted in the chamber in question. This may be arranged and secured in the chamber in question by means of threads " or other suitable securing means. The valve units 9 and 10 may be non-adj stable, so that they accordingly close and open, respectively, at predetermined pressures. However, it could often be desired to be able to adjust the closing and opening pressure, respectively, for at least one of and generally both valve units 9 and 10, and this may be accomplished by the fact that the spring tension of the spring 19 for the valve unit in question is adjustable by means of an adjustment means 28 located in the chamber 11 and/or 12 in question, e.g. a screw cooperating with a thread on the chamber wall, acting as an abutment for the spring 19, which here is illustrated as a helicoidal compression spring. The channel 6, 15 traverses the chamber 12 straight in front of the spring 19 of the valve unit 10, thus, so that the flow can pass the spring. The channel 7, 16 traverses in a corresponding way the chamber 11 straight in front of the spring 19 of the valve unit 9. The openings 13 and 14 of the chambers 11 and 12 are normally closed by means 22, here in the form of screw plugs. Further above it has been described how the valve device according to the invention may be utilized in connection with a gas bottle. However, the invention is not at all restricted thereto. For example the valve device may be used to assure a residual pressure in pressurized-fluid cylinders, through which considerable saving of energy may be achieved in comparison with the case when the pressure cylinders are evacuated completely during a return movement. In such an application may accordingly a pressurized-fluid cylinder, e.g. an air cylinder, replace the gas bottle schematically indicated at 1 in the drawing and it should be understood that it is of course not necessary that the valve device 2 is applied directly on the cylinder, but there may instead be a line therebetween. In such a case a valve is connected to the connection line 5, 7 by means of which pressurized fluid with a sufficient working pressure may be delivered to the cylinder through the valve unit 10. When the cylinder is evacuated the additional valve connects the connection line 5, 7 with the environment or a suitable receiver, so that accordingly air evacutated from the cylinder passes through the valve unit 9, which assure that a residual pressure is maintained in the cylinder. The valve device according to the invention may also be used in other situations in such pneumatic systems, in which it is desirable to assure a residual pressure in a pressurized-fluid space, but it is desired to be able to supply pressurized fluid to the space. Even though the invention primarily is suited for pressurized fluid in the form of gas hydraulic applications may also be possible. DETAILED DESCRIPTION OF AN ALTERNATIVE EMBODIMENT (FIG 2) The alternative embodiment illustrated in fig 2 is in essen¬ tials very similar to the one described in fig 1 and identical reference number has been maintained as far as possible. In the following only difference between the two embodiments will primarily be explained: In this embodiment the valve chambers 11, 12 are so arranged that they emerge in the same direction on the valve body 3, which in some cases may be of advantage in the accessibility point of view. The valve chambers are laterally and also axially displaced with respect to each other, so that their orifices 13, 14 on the outer side of the valve body are located at different levels. In this embodiment only the valve chamber 12 forms a part of the two flow paths through the valve body. In this embodiment the first flow path is formed by the connection line 6, the chamber 12, the line portion 15, the chamber 11, the line portion 7a and the connection line 5. The line portion 7a emerge into the bottom portion of the connection line 5 made as a hole and extends at an angle. More -exactly the line portion 7a is formed by two bores 25, 26 intersecting each other and worked from the outer side of the valve body, said bores being closed between the intersection point and the outer side of the valve body, e.g. by introducing plugs therein, which have been secured by soldering or in another way. The second flow path through the valve body is formed by the connection line 5, the line portion 16a, the chamber 12 and the connection line 6. The line portion 16a extends in the example at an angle between the bottom of the connection line or the hole 5 and the chamber 12, without traversing the chamber 11 as in the first embodiment. In the first flow path the valve unit 9 is active in order to close and open, respectively, whereas the second valve unit 10 is completely inactive, so that a free flow always takes place through its chamber 12. On the cont¬ rary, the valve unit 10 in the second flow path is active in order to close and open, respectively. Accordingly, when fluid is flowing from the space connected to the line 6 the non- return valve 9 opens, but this closes as soon as the pressure in the space has fallen below a predetermined level. However, when pressurized fluid is supplied to the space through the connection line 5 the non-return valve 10 opens. It has been shown in fig 2 how the closing means or the screw plugs 22 also constitute an abutment for the springs of the valve units. However, means as those indicated by 21 in fig 1 may of course be arranged to allow adjustment of the spring pressure and accordingly the opening and closing pressure of the valves. In fig 2 the connection line or the hole 5 is common to the line portion 7a and the line portion (16a), but it would of course also be possible to make the line portion 7a and the line portion 16a emerge on the outer side of the valve body 3 through separate orifices, which are together or separately connectable to suitable connection means. Thus, in such a case the connection line mentioned in the appended claims would be formed by two separate orifices and line sections in the valve body. Such an embodiment is comprised within the scope of the invention.

Claims: Claims 1. A valve device of the type intended to communicate with a space (8) for pressurized fluid, e.g. the interior of a gas bottle or a pressurized-fluid cylinder, through a first connection line (6), and allow outflow of pressurized fluid and communication with a pressurized-fluid source, respectively, through a second connection line (5) , the valve device being arranged to maintain a residual pressure in the pressurized- fluid space but allow supply of pressurized fluid to the space upon application of pressure on the second connection line, said valve device comprising two non-return valve units (9, 10), one (9) of which closes against pressurized-fluid outflow from the space when the pressure therein falls below a certain level, whereas the other (10) opens upon said application of pressure on the second connection line, c h a r a c t e r i z e d in that the non-return valve units are located in two different chambers (11, 12) in a body (3) of the valve device, and that each chamber is accessible from the outside of the body through an opening (13 and 14, respecti¬ vely) of its own separated from the outer orifices (23, 24) of the connection lines in order to insert and remove, respecti¬ vely, and possibly also adjust the valve units or parts thereof through these openings. 2. A device according to claim 1, c h a r a c t e r i z e d in that the connection lines (5, 6) emerge at two opposite ends of the valve device body and that the openings (13, 14) of the chambers emerge at an angle with the emerging direction of the connection lines, preferably perpendicularly thereto. 3. A device according to claim 1 or 2, c h a r a c t e r i z e d in that it comprises two flow paths and that the chamber (12) for at least one of the valve units forms part of both flow paths. 4. A device according to claim 3, c h a r a c t e r i z e d in that the connection lines (5, 6) are common to the two flow paths. 5. A device according to claim 3, c h a r a c t e r i z e d in that the two chambers (11, 12) for the valve units both form parts of each of these two flow paths. 6. A device according to claim 5, c h a r a c t e r i z e d in that the first connection line (6) communicates with the chamber (12) of the second valve unit, that this chamber communicates with the chamber (11) of the first valve unit through a line portion (15), said first valve unit (9) being arranged to close and open, respectively, the communication between this line portion (15) and its chamber (11), that the second connection line (5, 7) communicates with the chamber (11) of the first valve unit and that this through a second line portion (16) communicates with the chamber (12) of the second valve unit, said second valve unit (10) being arranged to close and open, respectively, the communication between this second line portion (16) and its chamber (12). 7. A device according to claim 6, c h a r a c t e r i z e d in that the chambers (11, 12) are substantially parallel to each other but mutually displaced perpendicularly to their longitu¬ dinal directions. 8. A device according to claim 7, c h a r a c t e r i z e d in that the chambers in a region in the central part of the valve device overlap each other and that on one hand the first connection line (6) and the first mentioned line portion (15), and on the other a portion (7) of the second connection line (5, 7) and the second line portion (16) are formed by rectili¬ nearly extending channels, preferably bores, each of which traverses one respectively of the chambers (11, 12) for the valve units. 9. A device according to any of the preceding claims, c h a r a c t e r i z e d in that each of the valve units (9, 10) in the bottom region of the chamber in question comprises a valve seat (17) cooperating with a mobile valve member (18), which by means of a spring (19) housed within the chamber is affected to cooperate with the valve seat in a closing manner, the pretension of at least the spring for one of the valve units being possibly adjustable by means of adjustment means (21) located in the chamber in question, e.g. a screw, acting as an abutment for the spring. 10. A device according to claim 8 and 9, c h a r a c t e r i z e d in that the channels ( 6 and 15 and 7 and 16, respectively) traverse the chambers straight in front of the springs (19) of the valve units.

Inventors: HEDLUND PER, HEDLUND, PER
Applicants: HEDLUND PER, SVAHN OVE, HEDLUND, PER, SVAHN, OVE
Application year: 1988
Main classification: F16K1
IPC codes: F16K1, F16K17, F17C13