STOP VALVE WITH ADJUSTABLE RESTRICTION

Abstract: In a stop valve (1) in which the maximum percentage opening is adjustable, the restriction of the valve is carried out by adjustment of a valve rod (3), on which a valve disc (4) is fixed, which cooperates with a valve seat (5) within the valve body (2) of the stop valve. The valve rod (3) consists of two axially movable parts (6, 7) which are adjustable in relation to each other by means of a driver connection, the most inner part (7) supporting the valve disc (4). In order to facilitate the adjustment and simplify the design the axially extreme valve rod part (6) is cylindric and has external threads (8), which cooperate with threads which are fixed in relation to the valve body. When said valve rod part (6) is rotated it moves in axial direction to or away from said valve seat (5). The axially inner valve rod part (7) is inserted in the cylindric extreme valve rod part (6) and the driver connection consists of a friction arrested screw connection (9) connecting the two valve rod parts.

Description: Stop valve with adjustable restriction. The following invention relates to a stop valve, the maximum percentage opening of which being adjustable, whereat the restriction of the valve is carried out by adjustment of a valve rod, which supports a valve body, which cooperates with a valve seat within the valve house of the stop valve, and whereat the valve rod consists of two axially, in relation to each other adjustable parts, which are adjusted by means of a driver connection, the inner part of those two parts supporting the valve body. A stop valve of this kind is known from e.g. DE 2 506 592, which discloses a two part valve element, which is adjustable by a knob. The adjustment is carried out by turning a valve rod, which is axially immovable, and one end of which is formed with a driver connection, which turns a second valve element via a 6-edge connection, said second valve element having a thread in its upper part. An adjustable stop means is screwed into the valve rod, which stop means decides the maximum open position of the valve element, that is to say the valve disc. A different kind of adjustment of a valve is known from a broschure called "Kombi 3+", published by Metallwerke Neheim Goeke & Co., GmbH (M.N.G.). The adjustment is carried out by closing the valve, setting the scale on zero, removing a protective cover and turning an adjusting ring to the wanted maximum percentage opening. The position is shown on a graduated scale. The object of the invention is to provide a valve, which is easy to adjust to a set position and is of a simple design and consists of a few parts. According to the present invention there is provided a stop valve, in which the axially extreme valve rod part is cylindric having external threads, which cooperate with threads which are fixed in relation to the valve body, so that when rotating said rod part it will travel in direction to or from the valve seat of the valve body, whereat the axially inner spindle part is inserted in the cylindric extreme spindle part and the driver connection consists of a screw connection which connects the two rod parts and is friction arrested. Hereby is achieved a different kind of adjustment from what is taught by the known art. According to the known art the adjustment of the valve is carried out by axial displacement of the valve body in relation to the valve rod, whereby an alteration of the percentage opening is possible only by contacting a stop means. The adjustment of the restricted opening according to the invention is carried out by relative axial displacement of the extreme rod part and the inner rod part, whereby the total valve rod length will be set. The inner rod part supports the valve body. The adjustment of the valve between closed position and maximum restricted position is carried out by rotating the two rod parts simultaneously in relation to valve house. When setting the maximum percentage opening the twist grip is set for the wanted opening rate on the scale. The inner rod part is rotated in this position by a toole until the valve disc contacts the valve seat. When thereafter the twist grip is adjusted to "0", the valve has the wanted restricted percentage opening, that is to say the restricted open position. The extreme rod part is threaded in order to be screwed into the valve body and the inner rod part is screwed into the extreme rod part by means of threads which are opposite (for instance anti clock wise) to the external threads (for instance clockwise) of the extreme rod part. To preset the maximum valve opening is hereby facilitated by that unintentional amendment of the set restriction is prevented when normally operating the valve. It is advantageously that the inner rod part has a neck, where the threads are formed and where a through hole is formed, in which a plug of elastic material is inserted. Unintentional amendments of the restriction is hereby prevented in case a turbulent water flow should effect the valve rod. Further it is an advantage if the inner rod part is provided with a shaped hole, for instance a 6-edged hole, in the end, which is directed towards the outside of the valve body, in which hole a toole can be inserted in order to rotate the inner rod part. The relative position of the two parts is hereby adjusted. The twist grip, which is used for adjustment of the valve, consists of a turning cap, which is securily inserted in the exterior part of the valve rod and which supports an indicating device, which corresponds to a scale on the valve house. In order to avoid unintentional flow of water by that the extreme rod part is totally unscrewed when the adjustment is carried out, a stop collar is formed on this rod part inside of and at a distance from its external threads, which stop collar will contact the corresponding threads of the valve body when the rod part is unscrewed in the direction from the valve body. An embodiment of the invention will be described in the following with reference to the enclosed drawings. Fig. 1 is thereby a longitudinal section of the valve, when it is open. Fig. 2 is a cross section of the valve perpendicular to the section according to fig. 1. Fig. 3 is the same section as the one of fig. 2 when the twist grip is adjusted to a wanted scale reading. Fig. 4 is the same section as shown in fig. 2 where the inner rod part is in closed position of the valve. Fig. 5 is a cross section of the valve according to fig. 2, where the twist grip is in the maximum opening of the valve. The design of the valve is shown in the cross sections according to fig. l and 2. The valve 1 thus includes a valve body 2, in which a valve rod 3 is rotated to move outwards and inwards by means of a screw connection with the valve body and which valve rod supports a valve disc 4 at its inner end. The valve disc 4 cooperates with a valve seat 5 within the valve body. The valve rod 3 consists of two rod parts 6 and 7, which are axially adjustably movable in relation to each other. The inner rod part 7 supports the valve disc 4. The two rod parts are connected with each other by means of a driver connection. The axially extreme rod part 6 is thus cylindric and has external threads 8, which cooperate with threads which are fixed in relation to the valve body. These threads are arranged in a rod house 10, which is inserted in the valve body 2, by means of a screw connection. The rod house 10 is fastened in the valve body 2 by means of the screw connection, so that when the extreme rod part 6 is rotated, it will move axially in relation to the rod house 10 and thus in relation to the valve body 2. Thus the valve rod 6 can take up steplessly different axial positions in relation to the valve rod house 10 and thus to the valve body 2. The inner valve rod part 7 is inserted in the cylindrically formed extreme valve rod part 6 and is adjustable in relation to this one by means of a driver connection. The driver connection consists of a friction arrested screw connection 9, which includes external threads on the inner valve rod part 7 and inside threads in the cylindric extreme valve rod part 6. As can be seen from the drawing, the inner valve rod part 7 has an extention in the form of a neck 11 and this part is the one which is screwed into the cylindric extreme valve rod part 6. A collar 16 is formed by this neck, which collar, when contacting the inner end of the extreme valve rod part 6, will limit the possible practicable length to screw the inner valve rod part 7 into the extreme valve rod part 6. The threads on the extreme valve rod part 6 are preferably right-threaded and the threads on the inner valve rod part 7 and on the cylindrical part of the valve rod part 6 are then left- threaded. It is hereby prevented that the valve rod parts 6 and 7 are rotated in relation to each other when the extreme valve rod part 6 is rotated by the twist grip 13. The twist grip 13 is fastened to the extreme valve rod part 6 and has signs which read the scale on the valve body. It is thus possible to read by the scale how far into the valve body the valve rod 6 is moved by that the turning position of the twist grip in relation to the scale can be decided. The twist grip 13 is turned when normally operating the valve for adjusting or closing the flow rate past the valve element and the valve seat. The percentage opening of the valve can now be set. This is done by that the relative position of the inner valve rod part 7 and the extreme valve part 6 is adjusted. This is accomplished by that the inner valve rod part 7 is rotated in relation to the extreme valve rod part 6. The rotation is accomplished by a toole, which is inserted in a shaped hole 14 in the outer end of the inner valve rod part 7, this hole for instance being a 6-edge hole. When turning the toole and hereby rotating the inner valve rod part 7, the inner valve rod part will amend its axial position in relation to the extreme valve rod part 6, which means that the overall length of the valve rod, that is to say the length of the effecting part of the inner valve rod part 7 and the external valve rod part 6, will be shortened or elongated. This means that when the valve rod part 6 is in its most unscrewed position, the distance between the valve disc and the valve seat 5 will be determined by the relative axially adjusted position of the two valve rod parts 7 and 6. This is shown in figures 3 to 5. It is presumed that in fig. 3 the twist grip is set for a wanted scale position. It is shown in fig. 4 that the inner valve rod part is screwed home until the valve is closed by that the valve disc 4 contacts the valve seat while the twist grip is retained in its set scale position. Hereafter the twist grip is adjusted to maximum opening, see fig. 5. Fig. 1 and fig. 2 show that the inner valve rod part 7 has a transversal hole through the neck where the threads are arranged, and a plug 12 of elastic material is pressed into this hole. The extreme valve rod part 6 is formed with a stop collar 15 above the threads 8, which stop collar stops the extreme valve rod part 6 to be unscrewed out of the valve body. This position thus forms the position of the valve rod part 6, which forms the maximum opening of the valve. The size of the maximum opening is thus decided by the axial position of the inner valve rod part 7 in relation to the extreme valve rod part 6. A preferred embodiment of the invention has been described above but variations hereof are possible. The external valve rod part 6 may for instance be inserted directly in the valve body by means of threads. Further it it possible to arrange the stop position of the extreme rod valve part 6 by other means than the shown stop collar 15.

Claims: CLAIMS 1. Stop valve (1) the maximum percentage opening of which being adjustable, in which the restriction of the valve is carried out by adjustment of a valve rod (3) , on which a valve disc (4) is fixed, which cooperates with a valve sea (5) within the valve body (2) of the stop valve, whereat the valve rod (3) consists of two axially movable parts (6, 7) which are adjustable in relation to each other by means of a driver connection, the most inner part (7) supporting the valve disc (4), c h a r a c t e r i z e d i n that the axially extreme valve rod part (6) is cylindric and has external threads (8) , which cooperate with threads which are fixed in relation to the valve body, so that when said valve rod part (6) is rotated it moves in axial direction to or away from said valve seat (5) , whereat the axial inner valve rod part (7) is inserted in the cylindric extreme valve rod part (6) and that said driver connection consists of a friction arrested screw connection (9) connecting the two valve rod parts. 2. Stop valve as claimed in claim 1, c h a r a c t e ¬ r i z e d i n that a valve rod housing (10) is inserted by means of threads in the side of the valve house (2) , which is opposite to the valve seat (5) , the extreme valve rod part (6) being inserted in this valve rod housing by means of threads. 3. Stop valve as claimed in claim 2, c h a r a c t e - r i z e d i n that the inner valve rod part (7) is connected with the extreme valve rod part (6) by means of threads, which are opposite in relation to the outside threads (8) of the extreme valve rod part (6) . 4. Stop valve as claimed in claim 1 or 3, c h a r a c t e r i z e d i n that the threads (9) of the inner valve rod part (7) are formed on a neck of the rod part, which neck has a transversal through hole, in which a plug (12) of elastic material is inserted. 5. Stop valve as claimed in claims 1-3, c h a r a c t e ¬ r i z e d i n that the end of the neck (11) , which is facing outwards, has a hole (14) , which for instance has six edges, in which hole a toole can be inserted for rotating the inner valve rod part (7) in relation to the extreme valve rod part (6) . 6. Stop valve as claimed in claims 1-5, c h a r a c t e ¬ r i z e d i n that a twist grip (13) is fastened onto the extreme valve rod part (6) , which twist grip has an indicating device, which corresponds to a scale on the valve body or on the valve rod houst (10) . 7. Stop valve as claimed in any of the preceeding claims, c h a r a c t e r i z e d i n that a stop collar (15) is arranged on the extreme valve rod part (6) inside and at a distance from the external threads (8) of said valve rod part, whereby the threads of the valve rod house (10) can be contact by said stop collar when said valve rod part is unscrewed in direction out of the valve house (2) .

Inventors: MOELBAEK JENS JOERGEN, MOELBAEK, JENS, JOERGEN
Applicants: DANFOSS AS, MOELBAEK JENS JOERGEN, DANFOSS A/S, MOELBAEK, JENS, JOERGEN
Application year: 1996
Main classification: F16K1
IPC codes: F16K1