RU2773161C1 - Backflow prevention device, hose coupler for hydrant and hydrant - Google Patents

Abstract

FIELD: hydrants.

SUBSTANCE: claimed group of inventions includes a hose coupling (210) for a hydrant, containing a backflow prevention device (212), which is installed in the internal channel of the hose coupling (210) of the hydrant. The backflow prevention device (212) comprises a return device (214) having a locking body (216), a sealing seat (218) and a return device (220). The return device (220) is designed to pre-stress the locking body (216) into a tight fit against the sealing seat (218). The locking body contains two sealing plates (216', 216'') of essentially semicircular shape, which are pivotally mounted with the possibility of rotation and which, by means of a return device (220), are preliminarily resiliently stressed in such a way that these sealing plates (216'; 216 '') are able to seal against the sealing seat (218) at least in some areas. The claimed group of inventions includes a hydrant with a hose coupling (210) configured to shut off the reverse flow of water through the hose coupling (210) inside the hydrant. The hose coupling according to the invention is distinguished by its compactness and can be reliably used with both underground and aboveground hydrants.

EFFECT: hydrant according to the invention prevents the water from flowing back through its hose coupling into the hydrant and thus into the connected water distribution system.

9 cl, 8 dwg

Description

The present invention relates to a backflow prevention device, a hose coupling for a hydrant, and also relates to a hydrant.

The hydrants are connected to the water distribution system and constitute water intake fittings to enable the fire brigade as well as public and private users to draw water from the water distribution system. The network pressure in the water distribution system is usually approx. 6-9 bar. The hydrants comprise a pipe for supplying water with an inner space and an outer side, this water distribution system usually being connected to the inner space via a section of the inlet to the pipe located on the bottom side. The intake of water from the internal space is carried out through the side pipes.

The problem with the technical solutions according to the prior art lies in the fact that contaminated water from the outside can be pressed, respectively, sucked through the hose coupling into the hydrant and further into the water distribution system.

Publication DE 10 2006 028 854 discloses a backflow prevention device with a cylindrical body and a flange at the first end and an outlet side at the second end. This outlet side is provided with two bayonet catches to create a bayonet locking connection to, for example, one (external) fire hydrant. Inside the body of the backflow prevention device, a vertically movable shut-off valve element is installed, which, under the action of flowing water, rises from the valve seat integrated into the backflow prevention device, and in the closed state of the hydrant, it lies against the valve seat and, thereby, locks the backflow prevention device. Such a backflow prevention device is fitted with its flange onto the outlet of an underground type hydrant and is screwed on.

A problem with such a backflow prevention device of the prior art is that it must be connected via its flange to the outlet of an underground type hydrant, for example by tedious screwing. However, bolts have to be installed and tightened in hard to reach areas. The loosening of these bolts is also complicated by poor accessibility, contamination deposits and, in particular, corrosion, and is time consuming. Appropriate seals should also be provided between the backflow preventer and the outlet, such as a rubber seal between the backflow preventer flange and the hydrant outlet. A further problem with the known backflow prevention devices is that in the installed position in terms of dimensions, for example, in terms of length, diameter, respectively, in general, in terms of dimensions, they form an expansion of excessively large dimensions at the outlet of the hydrant. As a result, for example, problems with the required area arise. Because of this large expansion, the hitherto known backflow prevention devices do not find use in overhead hydrants. Another disadvantage of hitherto known backflow prevention devices is that they can be tampered with, damaged or removed.

Therefore, it is an object of the present invention to provide a backflow prevention device which does not have the disadvantages mentioned above.

This problem is solved by means of a backflow prevention device with the features given in independent claim 1 of the claims. Preferred embodiments of the device, as well as a hose coupling for a hydrant, and a hydrant with such a hose coupling are described in other claims.

According to the present invention, a backflow prevention device is provided, which is intended to be installed in the internal channel of a hydrant hose coupling. Said backflow prevention device comprises a reverse device (backstop device) which comprises a locking body, a sealing seat and a return fixture, said return fixture being designed to resiliently stress the locking body into a sealing fit against the sealing seat.

In this way, a backflow preventer is obtained, which can be inserted through a hose coupling provided with a backflow preventer for most of its length into the outlet of the hydrant. As a result, the backflow preventer substantially extends completely within the outlet of the hydrant and does not protrude from the outlet of the hydrant or only slightly. In this way, in an unexpected and surprising way, the advantage is achieved that the hydrant provided with a backflow preventer remains still compact. In addition, the problems associated with the lack of space are eliminated and the aesthetic perception is not compromised. Likewise, unauthorized manipulation and theft can be prevented.

In one preferred embodiment of the anti-backflow device, the return means comprises at least one compression spring which is oriented in the axial direction of the internal passage of the hose coupling, this compression spring being designed to preload the locking body in a hermetic manner against the sealing seat. Said compression spring securely compresses the locking body against the sealing seat, so that this reverse device is securely locked in an unpressurized state (no water intake). This prevents water, possibly contaminated fire extinguishing water, foreign substances or generally solid or liquid substances from entering the water distribution system through the water supply pipe. As soon as the hydrant is opened, the water pressure applied to the closing body pushes it in the direction of opening, thereby ensuring a reliable intake of water.

In one preferred embodiment of the backflow prevention device, the sealing body is provided at least in some areas with a circumferential seal. This circumferential seal can be placed in a groove provided in a surface area of the locking body.

In one preferred embodiment of the backflow prevention device, said locking body is axially guided by a plurality of ribs provided in the circumferential direction around this locking body. Due to this axial direction, distortion of the locking body is prevented. Thus, the reverse device is always securely closed and opened.

In one preferred embodiment of the backflow preventer, said ribs are integral with portions of the inner channel of the hose coupling. For example, these ribs may be formed by corresponding recesses on the inner perimeter of the inner channel in such a way that the ribs remain. As a result, water can flow out through said corresponding recesses. This production proved to be reliable and economical.

In one preferred embodiment of the backflow prevention device, said locking body converges substantially conically at least in the locking direction. In one example, the sealing seat, at least in the sealing zone, can be shaped to correspond with said conical embodiment of the locking body. In this way, the sealing body or the seal attached to it, with a surface enlarged in the circumferential direction, comes into a hermetic abutment against the sealing seat and can reliably seal said reverse device.

In one preferred embodiment of the backflow prevention device, the locking body comprises at least two partial bodies that are connected to each other, at least one of the partial bodies being provided with a circumferential recess for receiving a seal. In this embodiment, such a seal can be pushed onto said circumferentially extending recess of one of the partial bodies in a conveniently accessible way, for example by elastic deformation of the seal. Both of these partial bodies can then be connected to each other, for example by means of a threaded connection. This circumferential seal is thus held positively between the two partial bodies.

In one alternative embodiment of the backflow preventer, the locking body is integrally formed and provided with a circumferential recess to accommodate the seal. This seal can be inserted into the recess, for example by elastic deformation, and remains securely in place due to its elastic force.

In one preferred embodiment, the backflow prevention device comprises at least one axle, which is connected at one end to the locking body, and at the other end is spring-elastically prestressed to the hose coupling. This embodiment prevents possible misalignment and thus ensures a reliable prestressing of the sealing body against the sealing seat.

In an alternative embodiment of the backflow prevention device, the locking body comprises at least one sealing plate pivotally connected by means of a hinge, which is prestressed spring-elastically by means of said resetting device in such a way that this sealing plate, at least in some areas, can seal against sealing surface. In this alternative embodiment, said reverse device is opened and, accordingly, closed by means of a sealing plate formed, for example, essentially circular, which is spring-elastically prestressed against the sealing surface. Said backflow prevention device according to this embodiment is distinguished by its reliability. In addition, this backflow preventing device is economical to manufacture.

In one preferred embodiment of the backflow prevention device, said at least one sealing plate can seal against the sealing surface with its circumferential portion. In another preferred embodiment of the backflow prevention device, the closing body comprises two sealing plates of substantially semicircular shape. In a further preferred embodiment of the backflow prevention device, these semicircular shaped sealing plates are pivotally hinged in such a way that, accordingly, its semicircular shaped peripheral portion can seal against the sealing surface. Preferably, said resetting device comprises a torsion spring, which, with at least one of its arms, prestresses at least one sealing plate in a resilient manner against the sealing seat. Preferably, the resetting device comprises a torsion spring with two arms, the two arms respectively resiliently prestressing said two sealing plates into a seal against the sealing seat. This preload can thus be applied particularly reliably to both sealing plates of a semicircular shape.

In a preferred embodiment, the backflow prevention device also comprises a base part for pivotally mounting said at least one sealing plate, this base part being able to fit into the inner channel of the hose coupling. Preferably, the base part comprises a flange, which can be hermetically connected with its outer surface to the inner surface of the inner channel of the hose coupling. Thus, the base part can be securely sealed against the inner channel.

The present invention also relates to a hose coupling for a hydrant comprising a backflow prevention device according to any one of claims 1 to 17 for preventing the back flow of water through the hose coupling into the interior of the hydrant. The hose coupling according to the invention can be connected to the water outlet or the outlet of the hydrant, for example by means of a threaded connection, and also allows the connection of the water hose by means of a corresponding coupling on the water hose, for example in the form of a dog clutch. The hose coupling according to the invention is distinguished by its compactness, since it combines both the hose coupling itself and said backflow prevention device. Despite the presence of a backflow prevention device, this hose coupling according to the invention protrudes from the water outlet of the hydrant no more than, for example, conventional hose couplings. Thus, such a hose coupling can be reliably used with both underground and aboveground hydrants.

In one preferred embodiment, said hose coupling is made for threaded connection to the water outlet of the hydrant. In one example, this hose coupling, by means of the male thread provided thereon, can be simply and securely screwed into a mating female thread inside the outlet of the hydrant.

This invention also relates to a hydrant with a hose coupling, made according to paragraphs 18 or 19 of the claims, and designed to block the reverse flow of water through the hose coupling into the hydrant. Said hydrant may be an underground type hydrant or an overhead type hydrant. The hydrant according to the invention prevents the water from flowing back through its hose coupling into the hydrant and thus into the connected water distribution system.

Here it should be clearly indicated that the above-described embodiments can be combined in any way. Excluded are only combinations of such embodiments which, due to the combination, could lead to inconsistencies.

The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the drawings. The drawings show the following.

Fig. 1a is a sectional view of a hose coupling with a backflow preventer in the extended state of the locking body, in the first representation;

Fig. 1b is a sectional view of the hose coupling shown in Fig. 1a with the backflow prevention device in the extended state of the locking body, in the second view;

2a is a sectional view of the hose coupling shown in figs.

Fig. 2b is a sectional view of the hose coupling shown in Fig. 2a with the backflow prevention device in the retracted state of the locking body, in the second view;

Fig. 3a, Fig. 3b is a sectional view of a hose coupling with a backflow prevention device in open and closed state, in another embodiment; and

Fig.4a, Fig.4b is a sectional view of a hose coupling with a backflow prevention device in open and closed state, in the following embodiment.

In Fig.1a-2b shows the hose coupling 10, the respective sectional views. The hose coupling 10 may be threaded to a hydrant outlet (not shown). This hose coupling 10 is provided with a backflow prevention device 12 inside or in its inner passage.

Said backflow prevention device 12 comprises a backflow device 14 which allows water to flow out of the hydrant (in these drawings the direction of water outflow runs from right to left, see also arrows W in FIG. 1a), but prevents the water from flowing back into the hydrant. Thus, water can be taken from the hydrant, however, no water can be let in through the hose coupling 10 into the hydrant, respectively, be sucked through it. Figures 1a, 1b show the hose coupling 10 in a state with the locking body 16 extended, while in Figures 2a and 2b this hose coupling 10 is shown in the state with the locking body 16 retracted.

The images in FIGS. 1a and 1b differ from each other in that the hose coupling 10 is shown from different angles. In this case, FIG. 1b shows the hose coupling 10 of FIG. 1a, however, rotated axially through an angle of 90°. The same relationship of provisions also takes place between Fig.2a and 2b.

The return device 14 comprises a locking body 16, a sealing seat 18 and a return fixture 20 which resiliently prestresses the locking body 16 into a tight seal against the sealing seat 18. In the embodiment shown in FIGS. 1a-2b, the return fixture 20 comprises a compression spring 22 , which is oriented in the axial direction of the inner channel. This compression spring 22 hermetically presses the locking body 16 against the sealing seat 18. To do this, said compression spring 22 is mounted on the axle 24. One end of the axle 24 is connected to the locking body 16. The axle 24 is installed in the thrust (axial) bearing 26 in such a way that this axis 24 can be axially guided. Thrust bearing 26 reliably prevents possible misalignment of axle 24 during its axial movement.

Mounted on the axis 24, the compression spring 22 at one end is adjacent to the flat section of the stop 28, which in turn is rigidly connected to the body of the hose coupling 10. The other end of the compression spring 22 is adjacent to the section of the cap 29, which is connected to the distal end of the axis 24. Compression spring 22 applies a pressing force between the stop 28 and the cap 29 of the axis 24, as a result of which the locking body 16 is prestressed (loaded) to the body of the hose coupling 10.

In the unpressurized state of the hydrant (no water intake), the axis 24 is pressed against the stop 28 (and thus from the body of the hose coupling 10) under the action of the elastic force of the compression spring 22, as a result of which the locking body 16 is pressed against the sealing seat 18 (see Fig. 2a and 2b). The locking body 16 is pushed in in this situation. This locking body 16 is pressed against the sealing seat 18 by the elastic force of the compression spring 22, so that the return device 20 is securely locked in this state. Thus, in an advantageous manner, no water can enter the hydrant from the outside.

In the case of water intake (see FIGS. 1a, 1b), the water presses against the inside of the hydrant surface of the locking body 16. The force exerted by the pressure of the water on the locking body 16 moves it against the elastic force of the spring to the open position. The locking body 16 is extended in this situation. Thus, in this state, water can be reliably drawn from the hydrant.

As soon as the hydrant closes again, the elastic force of the spring will prevail and again force the locking body 16 into a snug fit against the sealing seat 18. This prevents backflow into the hydrant of, for example, fire extinguishing water.

For sealing, the locking body 16 is provided with a circumferential seal 30 designed to positively seal against the sealing seat 18. Said seal 30 may comprise a rubber-based material. In the embodiment shown, the locking body 16 comprises two partial bodies 32', 32'' which are connected to each other. The outwardly facing part body 32' is provided with a circumferential recess into which the seal 30 can be fitted laterally and can be removed accordingly. As soon as both partial bodies 32', 32'' are connected to each other, a form-fitting seal 30 will be held between both partial bodies 32', 32''. Although not shown, said recess can also be made in the other partial body 32'', or such a recess can be formed in both partial bodies 32', 32''. Further, although not shown, the locking body may be integral and provided with a circumferential recess to receive the seal.

The inner channel of the hose coupling 12 is provided with a plurality of ribs S along its perimeter, against which the locking body 16 abuts along its perimeter, at least in some areas. Thereby, the locking body 16 can be reliably guided by the ribs S in the axial direction. These ribs S can be made in one piece with the (material) portions of the inner channel of the hose coupling 10, for example by making corresponding recesses A in the material of the inner channel. Those portions of the inner channel in which material has not been removed thus form corresponding ribs S. There is thus one rib S between adjacent recesses A. In the extended state of the locking body 16, water flows out through the recesses A towards the outlet side, as shown in FIG. 1a direction arrow W. The locking body 16 can converge substantially conically at least in the locking direction, i.e. towards the inside of the hydrant. This closing body 16 can converge essentially conically also towards the outlet side of the hydrant. For example, eddies in the outflowing water can be prevented in this way. As a result, the flow of water can be optimized, for example in terms of optimum water flow rate.

In the idle state of the hydrant, with the retracted position of the locking body 16 (see Fig. 2a, 2b), the outlet side of the hose coupling 10 can be sealed, respectively, protected from the external environment using a plug 34. 36 and the corresponding recesses on the edge of the plug 34 can be engaged with each other in a cam-like connection with each other. The plug 34 may have a prestressing mechanism 38 comprising a stem 40 which, by means of a preloaded compression spring 42, presses against the distal end of the locking body 16. Thereby, the locking body 16 continues to be firmly pressed against the sealing seat 18.

3a, 3b and 4a, 4b respectively show a hose coupling 110; 210 with built-in device 112; 212 prevent backflow in the open and closed state, in the following different implementations. In both embodiments, the device 112; 212 prevent backflow contains a reverse device 114; 214, which blocks the flow of water back into the hydrant while the hydrant is closed. Similarly, in both embodiments, reverse device 114; 214 includes a locking body 116; 216, sealing seat 118; 218 and return fixture 120; 220, which resiliently prestresses the locking body 116; 216 in a tight fit to the sealing seat 118; 218.

Figures 3a, 3b show a sectional view of the hose coupling 110 with the backflow prevention device 112 in the open and closed state, respectively, in another embodiment. In the illustrated embodiment, the locking body 116 is configured as a pivotally hinged sealing plate 116, and the resetting device 120 is configured as a torsion spring 120 or a torsion rod spring (shown schematically) that resiliently prestresses the sealing plate 116 against the body of the hose coupling 110 in this manner that this sealing plate 116 with its peripheral (circumferential) section, at least in some places, hermetically abuts against the sealing surface 118. As soon as the hydrant opens, the force applied in the flow direction to the sealing plate 116 becomes greater than the elastic force of the torsion spring 120 Because of this, the sealing plate 116 moves away from the sealing seat 118 and water flows to the outlet side. As soon as the hydrant is closed again, the torque generated by the torsion spring 120 will take over and the sealing plate 116 will again press against the sealing seat 118. This prevents water from flowing back into the hydrant.

Figures 4a, 4b show a sectional view of the hose coupling 210 with the backflow preventer 212 in an open and closed state, respectively, in another embodiment. In the embodiment shown in these figures, the locking body is in the form of sealing plates 216 including two sealing plates 216', 216'' of a substantially semi-circular shape. These sealing plates 216', 216'' are pivotally connected in such a way that their respective circumferential (circumferential) portion of the semi-circular shape seals against the sealing seat 218. Further, the return device is embodied as one or more torsion springs 220, respectively, torsion rod springs. (represented schematically), each of which, for example, by means of both arms of the torsion spring prestresses the sealing plates 216', 216'' in an airtight manner against the sealing seat 218, for example, by means of both arms of the torsion spring. both sealing plates 216', 216'' are installed. The base part 221 can be inserted into the inner channel of the hose coupling 210. To do this, the specified base part 221 has a flange 223, which, on its outer surface, is hermetically connected to the inner surface of the inner channel of the hose coupling 210, for example, by means of an O-ring. Said backflow prevention device 212 can be removably fixed to the internal channel of the hose coupling 210 by means of a spring retaining ring or an elastic Seger lock ring. Maintenance work can also be simplified.

As soon as the hydrant opens, the force applied in the flow direction to the sealing plates 216', 216'' becomes greater than the torque applied by the torsion spring 220, respectively, the torsion rod spring, whereby the sealing plates 216', 216'' are separated from the sealing plate. saddle 218 (see Fig.4a). Thus, water flows to the outlet side of the hydrant. As soon as the hydrant is closed again, these sealing plates 216', 216'' will again be pressed by the torsion spring 220 against the sealing seat 218, respectively, to prevent the water from flowing back into the hydrant (see Fig. 4b).

Claims (10)

1. Hose coupling (210) for a hydrant, containing a device (212) to prevent backflow, which is installed in the internal channel of the hose coupling (210) and contains a return device (214) having a locking body (216), a sealing seat (218) and a return device (220), moreover, this return device (220) is made with the possibility of preliminary spring-elastic tension of the locking body (216) in a tight fit to the sealing seat (218), wherein said locking body comprises two sealing plates (216', 216'') of essentially semicircular shape, which are hingedly mounted with the possibility of rotation and which, by means of a return device (220), are preliminarily resiliently stressed in such a way that these sealing plates (216' ; 216'') are able to seal against the sealing seat (218) at least in some areas. 2. A hose coupling (210) according to claim 1, wherein said sealing plates (216'; 216'') are configured to seal against the sealing seat (218) with their circumferential portion. 3. Hose coupling (210) according to claim 1 or 2, wherein the sealing plates (216', 216'') of the semicircular shape are pivotally mounted so that the circumferential portion of the semicircular shape of each of them is able to seal against the sealing surface (218). 4. Hose coupling (210) according to any one of claims 1 to 3, wherein the return device has a torsion spring (220) with two arms, each of these two arms resiliently prestressing said two sealing plates (216', 216' ') into a seal against the seal seat (218). 5. Hose coupling (210) according to any one of claims 1 to 4, further comprising a base part (221) intended for rotary installation of said at least one sealing plate (216', 216''), this base part (221 ) is configured to be placed in the inner channel of the hose coupling (210). 6. Hose coupling (210) according to claim 5, wherein the base part (221) has a flange (223) which is configured to be sealed on its outer surface with the inner surface of the inner channel of the hose coupling (210). 7. Hose coupling (210) according to any one of claims 1 to 6, designed to block the reverse flow of water through the hose coupling (210) into the hydrant. 8. Hose coupling (210) according to claim 7, made with the possibility of threaded connection with the water outlet of the hydrant. 9. Hydrant with a hose coupling (210) according to claim 7 or 8, configured to block the reverse flow of water through the hose coupling (210) into the hydrant.

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