VALVE WITH A HELICAL SPRING AS VALVEMEMBER

Abstract: A valve for closing or controlling a fluid flow, comprising a control element (4), which for controlling the fluid flow provides for a variable passage area through the device. In order to provide a valve having a simple design and a reliable function, the control member of the valve is constituted by a helix (4), the variable passage area being constituted by the area between the convolutions of the helix.

Description: Valve with a herical spring as valvemember The present invention relates to a valve for closing or controlling a fluid flow. Many different constructions of valves for closing or con¬ trolling fluid flows are previously known. The object of the present invention is to provide a new valve which has a larger field of application, is easier and cheaper to manufacture and is in certain respects also better than the previously known valves. In order to comply with this object, the valve according to the present invention is characterized in that the variable passage area is con¬ stituted by the area between the convolutions of a helix. In a preferred embodiment of the valve according to the invention this is provided with means for reducing the pressure drop of the fluid flow when this flows through the area between the convolutions of the helix. In a valve of this kind the generation of vibrations and noise in the valve caused thereby are obstructed, which vibrations can arise at great pressure drops over the helix. The valve can be designed so that the convolutions of the helix directly engages each other when the valve is closed, but especially when the valve is designed as a shut-off valve it is preferred to form the con¬ volutions of the helix from rubber or another material. The characteristic of the valve, i.e. the variations of the passage area in relation to the distance between the ends of the helix, can be given substantially any desired function, for example by forming the helix as a conical helix, or by changing the cross sectional size of the con¬ volutions of the helix at different portions thereof. - UREAU O Pl _ , WIPO Λ In an advantageous embodiment of the invention, the helix is provided in a passage-way ofthe valve body of a tap or ball valve in order to provide in the valve a flow control device which is activated when the valve is opened. Thereby, there is provided a combined shut-off and flow control device for for example water pipe .systems. The invention is described in the following with reference to the accompanying drawings. Fig. 1 is a sectional view of a valve according to the invention. Fig. 2 is a sectional view corresponding to Fig. 1 of an other embodiment of the valve according to the invention. Figs. 3a and 3b show different positions of a valve according to the inventio intended to be used as a flow control device. Fig. 4 shows a valve according to the invention designed as a check valve. Fig. 5 shows a further embodiment of a valve according to the invention designed as a flow control device. Fig. 6 is an axial section of a tap valve includin a valve according to the invention. Fig. 1 is an axial section of a valve according to the invention, the device being connected with a pipe 2. The control element of the valve is constituted by a helix 4 having one end connected with a shoulder 6 of the pipe 2 and supporting at its other end a pressure plate 8. The pressure plate 8 constitutes a flow resistance having a predetermined passage area. The fluid flow through the pipe 2 takes place in the direction of the arrows, and thus, the fluid flows between the convo- lutions of the helix. Thereby, the helix will determine the passage are of the valve in dependency of the area between the convolutions. The flow of fluid through the pipe actuates the pressure plate 8 which is exposed to a greater pressure from the fluid when the fluid flow is in¬ creased, so that the plate 8 is forced to the right which in turn bring about a compression of the helix 4. The compression of the helix 4 provides for a reduction of the passage area between the convolutions of the helix in turn providing for a throttling of the fluid flow. When the fluid flow is reduced, the helix forces the pressure plate 8 to the left in the figure, so that the passage area between the convolutions of the helix is increased and also the fluid flow is thereby increased. /" U 0 The valve according to Fig. 1 is suitable for being used as an auto¬ matic shut-off valve which is actuated at an unusually great flow through the pipe 2, for example because of a pipe fracture down-stream from the flow control device. If such a pipe fracture takes place, the helix 4 will be compressed to a closed position and will be maintained in this position because of the pressure difference in the pipe at each side of the flow control device. Fig. 2 shows an automatic flow control device which is included in a pipe 10. In the pipe 10 there is provided a plate 12 firmly connected with the pipe wall and supporting one end of a helix 14. Radially out¬ side the helix 14, the plate 12 is provided with passage openings 16. At the end opposite to the plate 12, the helix supports a pressure plate 18, which is guided for an axial movement in the pipe 10. The plate 18 is provided with a central inlet opening 20. The plate 12 as well as the plate 18 form flow resistances having predetermined passage areas for reducing the pressure drop over the helix 14. If said pressure drop is too great, there is created vibrations in the helix in turn leading to noise. The flow control device according to Fig. 2 works according to the same principles as the device according to Fig. i. Thus, the flow control device according to Fig. 2 maintains a constant flow in the pipe by the fact that the passage area between the convo¬ lutions of the helix is reduced when the flow and the pressure on the plate 18 increase so that the flow is again reduced and vice versa. Figs. 3a and 3b show a flow control device corresponding to the device of Fig. 2 ' positioned in a pipe 22. Thus, the control device according to Figs. 3a and 3b comprises a plate 24 supporting a helix 26 and being formed with passage openings 28 peripherally outside the helix. At the opposite end in relation to the plate 24, the helix 26 supports a pressure plate 30 having a central passage opening 32. The plates 24 and 30 constitute flow resistances having predetermined passage areas for reducing the pressure drop over the helix 26. The flow control device according to Figs. 3a and 3b differs from the flow control de- vices according to Figs. 1 and 2 by the fact that the helix is conical. -BUREAT * OMPI This fact provides that the control device according to Figs. 3a and 3b obtains an other characteristic than flow.control devices having a cylindrical helix. In a flow control device having a cylindrical helix, the variation of the passage area is proportional to the variations of the length of the helix, while a flow control device having a conical helix has another characteristic. Thus, an increased pressure on the plate 30 of the helix 26 will reduce the distance between the ends of the helix by initially compressing the convolutions having the greatest diameter. Thus, a compression of the helix from the position shown in Fig. 3 initially provides for a relatively rapid reduction of the passage area, as the convolutions having the greatest diameter is force against each other, while in the lower control region, i.e. at small passage areas, there is provided a greater accuracy of the control of the flow. By forming the helix in a suitable way with regard to the diameter of the convolutions and/or the sectional size of the convo¬ lutions at different positions of the length of the helix, it is possib to provide a flow control device having any desired characteristic. The plate 24 is provided with a central opening 33 having a relatively smal diameter which provides for a more even passage of the fluid through the control device and obviates the closing of the flow control device at pressure shocks. Fig. 4 shows a device according to the invention which is designed as a check valve. The valve is provided in a pipe 34 and comprises a plate 36 connected with the pipe and having one end of a helix connected thereto. The other end of the helix supports a plate 40. The plate 36 has a central passage opening 42. The plate 40 has less outer diameter than the inner diameter of the pipe 34 for which reason there is formed an annular passage opening 44 around the plate 40. The flow directions through the valve are shown by means of arrows. Thus, it is apparent that the valve according to Fig. 4 is in all essential respects formed in the same way as the device according to Fig. 1, with the exception that the flow directions through the devices are opposite. A fluid flow through the valve in the directions of the arrow forces the plate 40 to the right according to Fig. 4, so that the helix 38 is retained in an extracted position and the fluid flow takes place between the con¬ volutions of the helix. If the fluid flow takes place in the opposite direction or the fluid flow terminates, the plate 40 is moved to the left in Fig. 4 in dependency of the strength of the helix so that the area between the convolutions is closed and a flow in the opposite direction is thereby obstructed. Dependent on the pretensioning of the helix 38 in the direction of contracted position, it is possible to provide for an opening of the valve at any desired flow in the direction to the right or to provide for a closing at any desired flow in the di- rection to the left in the figure. The flow control device shown in Fig. 5 comprises a valve housing 46 having an annular projection 48 and a locking ring 50 positioned in a groove in the housing. In the housing there is provided a conical helix 52 adapted to control the fluid flow through the control device ac¬ cording to the same principles as described above. At its small end, which is positioned up-stream, the helix 52 is connected with a flow resistance 54 in the form of a washer having a cylindrical edge portion 56, said washer being movable to the left in the housing acainst the action of the helix 52. The passage area of the flow resistance 54 is predetermined by the fact that the resistance is formed with two open¬ ings 57. In addition to the flow resistance 54 having a predetermined passage area the flow control device according to Fig. 5 includes a flow resistance having a variable passage area. The flow resistance having a variable passage area comprises a valve means 58 and a valve seating 62 constituted by a conical element 60. The element 60 is by means of an edge flange 64 fixed between the helix 52 and the projection 48. Thus, the valve means 58 is supported by the washer 54 and is moved together therewith, as the washer 54 is moved more or less to the left according to Fig. 5 dependent on the passage of the fluid through the flow control device. Dependent on the position of the washer 54 and thereby of the valve means 58 in relation to the valve seating 62 the passage area through the flow resistance having a variable passage area will variate. Together the flow resistance having a predetermined passage area and the flow resistance having a variable passage area cooperate for maintaining a substantially constant pressure difference over the helix 52 at different flow rates. Thereby, vibrations of the helix 52 and noise accompanying said vibrations will be quite elimi¬ nated in the valve. In spite of the fact that the flow control device according to Fig. 5 includes an extremely well developed control technique, the device consists of simple elements which in a fast and easy way can be mounted without use of screws or other fastening means requiring time for its mounting. This fact is a great advantage. In mounting a flow control device according to Fig. 5 it is only necessary to position the ele¬ ment 60 with its flange 64 in engagement with the projection 48, po¬ sition the helix with the thick end thereof against the flange 64, position the washer 54 with the valve means 58 positioned thereon inside the helix and finally position the locking ring 50 in the groove in the valve housing. Fig. 6 shows a flow control device of the kind shown in Fig. 5 included in the valve housing 66 of a tap valve 68. The valve housing 66 forms the housing of the flow control device, and thus, the elements forming the flow control device according to Fig. 5 are positioned in the passage opening 70 of the valve means 66. Therefore, the different ele¬ ments of Fig. 6 have the same reference numerals as in Fig. 5 with the addition "a". The valve means 66 is in a conventional way rotatably positioned in the valve housing of the valve 68, and thus, the valve shown in Fig. 6 constitutes a combined closing and flow control valve. The housing of the valve 68 is provided with openings 72 which allow that the flow control device can be made available for service and/or adjustment in the closed position of the valve means 66. In order to prevent fluid flow through the valve 68 if the valve means should by mistake have been so positioned that the fluid flows in the direction from the element 60a to the washer 54a, there is between said washer and the locking ring 50a provided a further washer 72 having a central opening 74. It is recognized, that fluid flow can take place - U ~ m • *7 ■ in the intended direction only when the washer 72 is present, as the washers 54a and 72 thereby are positioned at a distance from each other, but not in the opposite direction, as said washers thereby sealingly engage each other. Also in the embodiments of the device according to the invention de¬ scribed above, a washer of the same kind as the washer 72 can be present. The invention can be modified within the scope of the following claims. For example it can be preferred to provide a valve according to the invention with a control means consisting of a spring thread covered by an elastic material. The flow control device according to the invention is especially well suited for being used in hot water heating systems. To such systems there are connected a number of radiators and in order to provide for a correct functioning of the system .he flow of water to each radia¬ tor has to be adjusted. By providing a valve of the type shown in Fig. 6 in connection with each radiator it is possible to adjust the flow of water to each radiator by positioning a flow control insert in each valve providing for the correct and desired flow through that valve.

Claims: C L A I M S 1. A valve for shutting off or controlling a fluid flow, character¬ ized in that the variable passage area of the valve is constituted by the area between the convolutions of a helix positioned in a valve housing. 2. A valve as claimed in claim 1, characterized by means for reducing the pres-sure drop of the fluid flow at the flowing through the area- between the convolutions of the helix. 3. A valve as claimed in claim 2, characterized in that said means comprises a flow resistance having a predetermined passage area. 4. A valve as claimed in claim 2 or 3, characterized in that said means comprises a flow resistance having a variable passage area. 5. A valve as claimed in claim 3, characterized in that the end of the helix positioned down-stream is non-movably connected with a housing and the end of the helix positioned up-stream is connected with the flow resistance having a predetermined passage area and together therewith is movably arranged in the housing in such a way that the fluid flowing through the housing acts for displacing the flow resistance in a direction for compressing the helix. 6. A valve as claimed in claim 4 and 5, characterized in that the flow resistance having a variable passage area consists of a valve means and a valve seat, said means or said seat being positioned on the flow resistance having a predetermined passage area for being dis¬ placed in a direction for reducing the passage area of the flow resistance having a variable passage area when the flow resistance having a predetermined passage area is displaced in a direction for compressing the helix. 7. A valve as claimed in any of the preceding claims, characterized in that said helix is of conical shape. -B- O .<&,. V7 8. A valve as claimed in any of the preceding claims, characterized in that the helix consists of a thread covered with an elastic material. 9. A valve as claimed in any of the preceding claims, characterized in that the helix is positioned in a passage opening in the valve means of a tap or ball valve for constituting therein a flow control device which is acting when said valve is in its opened position. -BUREAU OMPI

Inventors: DERMAN K, SOEDERBERG R
Applicants: DERMAN K, SOEDERBERG R, SOEDERBERGS ING BYRA, SOEDERBERGS INGENJOERSBYRA AB
Application year: 1978
Main classification: F16K1
IPC codes: F16K1, F16K5, F16K17, F16L55