SHUTOFF VALVE

Abstract: A shutoff valve with a stationary (2) and a movable member (3). The movable member (3) comprises at least one primary means (5), such as the valve disk, and a secondary means (6), such as the valve shaft. When the shutoff valve is activated, the secondary valve means (6) is moved immediately before the valve is opened or closed in the entire lift of the valve and consequently relative to both the stationary member (2) and the primary valve means (5). The primary valve means (5) is not moved until after the latter movement. As a result, the force necessary for activating the valve is a slight force compared to the force necessary in case the primary (5) and the secondary (6) valve means were mutually fixed.

Description: Title: Shutoff valve Technical Field The invention relates to a shutoff valve comprising a stationary and a movable member, where the movable member at least comprises a primary means, such as the valve disk, and a secondary means, such as the valve shaft. Background Art US-PS No. 4,790,346 discloses a shutoff valve with a rotatable valve disk staggered relative to the outlet in such a manner that the sealing applies to different loca¬ tions on the gasket and further such that the valve re¬ quires less opening force. Although the valve disk of such a valve does not communicate continuously with the valve shaft forming the anchoring means in a solenoid, the movement of the anchoring means relative to the valve disk is minimal. US-PS No. 4,449,691 discloses an electromagnet activating a valve, and whereby a spring arrangement reduces the acce¬ leration effects on both the valve seat and the valve disk. Despite the latter measures, the anchoring means does not move a long distance before the valve is activated. Disclosure of Invention The object of the invention is to provide a shutoff valve of the above type, where the amount of energy necessary for activating the shutoff valve is minimized, and where the activating energy is independent of the pressure conditions to a higher degree than previuosly, said pressure condi¬ tions applying on both sides of the valve disk. The shutoff valve according to the invention is character- ised in that immediately before the valve is opened or closed, the secondary valve means is moved through almost the entire lift of the valve and consequently relative to both the stationary valve member and to the primary valve means, and that the primary valve means is not moved until after said movement of the secondary valve means. In this manner it is rendered possible by way of a slight force to supply an amount of energy sufficient for accelerating and consequently for moving the secondary valve means rela- tive to the stationary member and the primary means. Simul¬ taneously, it is possible to achieve a good grip on or in the means activating the valve. An embodiment of the shutoff valve according to the inven¬ tion is characterised in that the primary and the seconda- ry valve means are interconnected through at least one driving means and through at least one carrier means. As a result the driving means can be prestressed during the movement of the secondary valve means relative to the primary valve means. Furthermore the primary valve means and the secondary valve means are rigidly interconnected in the opening or closing moment. According to the invention the primary valve means of the shutoff valve may substantially be made of a neutral or a non-magnetic material, and the secondary valve means may substantially be made of magnetic or magnetizable material, whereby the secondary valve means can be moved by means of a magnet simultaneously with the primary valve means being manufacturable of relatively light materials, such as aluminum. Furthermore according to the invention both the primary valve means and the secondary valve means may substantially be made of a magnetic or magnetizable material, whereby the effect of the driving means can be reduced. According to an advantageous embodiment of the shutoff valve according to the invention the driving means com¬ prises a resilient means, such as a spring, and the carrier means is formed by a flange. Moreover according to the invention, the shutoff valve may be characterised in that the movable member comprises a shaft, a secondary spring, a carrier ring, a valve disk, a valve gasket, a primary spring, a locking ring and a rubber knob, whereby a simple structure of the shutoff valve is obtained. According to an advantageous embodiment of the shutoff valve according to the invention, the secondary spring is less resilient than the primary spring, and the valve is moved by means of a solenoid. Finally the shutoff valve may according to the invention be characterised in that the movement of the secondary valve means before the opening or closing of the valve corresponds to more than approximately 70% of the lift, preferably between approximately 70% and approximately 90% of the lift, especially approximately 80% of the lift. In this manner sufficient energy is stored in the secondary valve means with the result that the primary valve means can open even when subjected to very strong counterpres- sures . Brief Description of the Drawing The invention is described in greater detail below with reference to the accompanying drawing, in which Fig. 1 is a perspective view of a shutoff valve according to the invention, Fig. 2 is a partially sectional view on a larger scale of the shutoff valve of Fig. 1, Fig. 3 illustrates the valve arrangement of Fig. 2, and Fig. 4 in princpiple the position of the anchoring means when the valve is closed and immediately before said valve is being opened. Best Mode for Carrying Out the Invention The shutoff valve is generally designated the reference numeral 1, cf. Fig. 1, and comprises a stationary 2 and a movable member 3, where the movable member 3 in turn com- prises a valve disk 51, a valve shaft 61, a carrier ring 53, a valve gasket 55, at last two torsion springs - a primary 67 and a secondary 65 torsion spring - a rubber knob 69 and a locking ring 66, cf. Figs. 2 and 3. The shaft 61 of the valve is magnetizable, and the primary spring 67 is arranged inside the valve shaft 61, said primary spring 67 usually providing the force keeping the valve closed. The force of the primary spring is such that the valve can be kept closed despite the surface forces caused by the pressure conditions applying on both sides of the closing area of the valve at the same time as the solenoid 40 is capable of opening the valve. The secon¬ dary spring is such that it is capable of ensuring that the primary valve means is kept pressed against the secon¬ dary valve means when the valve is open. The rubber knob 69 is placed inside the primary spring 67 in the shaft 61, said rubber knob dampening the impact effect of the anchoring means inside the solenoid 40 as well as ensuring a release of the valve in connection with a drop in ten¬ sion. The movable members of the valve are formed by the primary means and the secondary means, where the primary means may either be magnetizable or unmagnetizable , and where the secondary means usually is magnetizable. The primary means and the secondary means communicate by way of a spring arrangement in such a manner that the secondary means can be moved relative to the primary means . The movable member of the valve may comprise more than two mutually movable means. By the shutoff valve according to the invention, the dividing line between the primary valve means and the secondary valve means is placed immediately below the valve disk, but it is also possible to place said dividing line at a higher level within the magnetic field. The placing of the dividing line depends on the hammering effect or impuls by which the secondary valve means must be able to influence the primary valve means. The valve may be magnetically, electrically, hydraulicly or purely mechanically activated. The magnetic activation can be carried out by means of a movable magnet or a movable core, optionally a movable coil. Under all circum¬ stances, various ways are provided for optimizing the force/position function by means of lengths of tubes 30, 31, such as steel 31, and inclining surfaces 33 on the anchoring means inside the solenoid, cf. Fig. 4. A low copper consumption is aimed at in connection with the magnetic coil in order to minimize the costs. As to the electric activation a low consumption of power is aimed at both during the activating procedure and during the follow¬ ing maintaining of the open or closed position of the valve. The valve may be hydraulicly activated either by means of oil, air or another fluid. It may also be of interest to minimize the necessary activating power. When the valve is mechanically activated, it may also be of interest to minimize the activating force. The latter can also be achieved by the above hammering effect. The object of all the above measures is to ensure a reason¬ able ratio of often contradicting factors, such as pressure ratios in the valve and activating force, both with respect to costs and size. When testing and classifying valves for for instance gas in connection with gas boilers, the pres¬ sure ratios applying on the input side and the output side of the valve are of interest. The pressures on the input side are usually in the range of 10 mbar to 100 mbar, but the valve according to the invention is capable of operat¬ ing at an input pressure of up to about 600 mbar without increasing the magnetic system. It is possible to ensure a blocking for counterpressures - i.e. on the output side- of about 150 mbar. Provisions also apply to the tension necessary for activating the valve as well as to the tension at which the valve must close, such as in connec¬ tion with a drop in tension. The voltages are alternating current or direct current directly on the magnetic valve. The invention is not limited to the above embodiments but may be varied in many ways without thereby deviating from the scope thereof. Thus a slight movement - substan¬ tially less than 80% of the lift - can also cause an effect.

Claims: Claims 1. Shutoff valve comprising a stationary and a movable member, where the movable member at least comprises a primary means, such as the valve disk, and a secondary means, such as the valve shaft, c h a r a c t e r i s e d in that immediately before the valve is opened or closed, the secondary valve means (6) is moved through almost the entire lift of the valve and consequently relative to both the stationary valve member (2) and to the primary valve means (5) , and that the primary valve means (5) is not moved until after said movement of the secondary valve means . 2. Shutoff valve as claimed in claim 1, c h a r a c ¬ t e r i s e d in that the primary (5) and the secondary valve means (6) are interconnected through at least one driving means and through at least one carrier means. 3. Shutoff valve as claimed in claim 1 or 2 , c h a r¬ a c t e r i s e d in that the primary valve means (5) sub¬ stantially is made of a neutral or a non-magnetic material, and that the secondary valve means (6) substantially is made of magnetic or magnetizable material. 4. Shutoff valve as claimed in claim 1 or 2, c h a r¬ a c t e r i s e d in that both the primary valve means (5) and the secondary valve means (6) substantially are made of magnetic or magnetizable material. 5. Shutoff valve as claimed in one or more of the claims 1 to , c h a r a c t e r i s e d in that the driving means comprises a resilient means, such as in form of a spring (8) . 6. Shutoff valve as claimed in one or more of the claims l to 5, c h a r a c t e r i s e d in that the carrier means is formed by a flange (10) . 7. Shutoff valve as claimed in one or more of the claims 1 to 6 , c h a r a c t e r i s e d in that the movable member (3) comprises a shaft (61), a secondary spring (65), a carrier ring (63) , a valve disk (53) , a valve gasket (55), a primary spring (67), a locking ring (66) and a rubber knob (69). 8. Shutoff valve as claimed in one or more of the claims l o 7, c h a r a c t e r i s e d in that the secondary spring (65) is less resilient than the primary spring (67). 9. Shutoff valve as claimed in one or more of the claims l o 8, c h a r a c t e r i s e d in that the valve is moved by means of a solenoid (40). 10. Shuttoff valve as claimed in one or more of the claims 1 to 9 , c h a r a c t e r i s e d in that the movement of the secondary valve means (6) before the opening or closing of the valve corresponds to more than approximately 70% of the lift, preferably between approximately 70% and approximately 90% of the lift, especially approximately 80% of the lift.

Inventors: HANSEN JOERN HAVGAARD, HANSEN, JOERN, HAVGAARD
Applicants: BM CONTROLS AS, BM CONTROLS A/S
Application year: 1990
Main classification: F16K31
IPC codes: F16K31