HOSE COUPLING FOR A HYDRANT, AND HYDRANT

Abstract

A hose coupling for a hydrant has a ventilation device. The ventilation device has a non-return valve that is received in a receptacle incorporated into an outer flange of the hose coupling.

Claims

1-18. (canceled)

19. A hose coupling (10) for a hydrant, wherein the hose coupling (10) comprises a ventilation device (18), wherein the ventilation device (18) comprises a non-return valve (20), which is accommodated in a receptacle (22) incorporated into an outer flange (24) of the hose coupling (10).

20. The hose coupling (10) according to claim 19, wherein the non-return valve (20) comprises a bushing (26) insertable at least in sections into the receptacle (22) and a valve body (28) inserted at least in sections into the bushing (26) and adjustable in the axial direction of the bushing (26).

21. The hose coupling (10) according to claim 20, wherein the valve body (28) comprises a cylinder section (32), which is inserted at least in sections into the bushing (26) and can be guided therein in the axial direction, and a stop (36) adjoining the cylinder section (32).

22. The hose coupling (10) according to claim 21, wherein the stop (36) projects radially above the cylinder section (32).

23. The hose coupling (10) according to claim 21, wherein the stop (36) is adjustable in a section of the receptacle (22) between the bushing (26) and an end surface (34) of the receptacle (22).

24. The hose coupling (10) according to claim 21, wherein the non-return valve (20) further comprises a ring seal (38) arranged to circumferentially seal the stop (36) from the end face of the bushing (26) facing the stop (36) when the non-return valve (20) is in the closed state.

25. The hose coupling (10) according to claim 24, wherein the ring seal (38) is placed in a section around the cylinder portion (32).

26. The hose coupling (10) according to claim 24, wherein the end face of the bushing (26) facing the stop (36) is formed with a conically shaped sealing surface.

27. The hose coupling (10) according to claim 20, wherein the bushing (26) is cylindrical in shape and is provided at least in sections with an external thread, designed to be accommodated by threading in an internal thread correspondingly incorporated into the receptacle (22).

28. The hose coupling (10) according to claim 21, wherein the stop (36) is provided with at least one projection on a side facing the end surface (34) of the receptacle (22).

29. The hose coupling (10) according to claim 21, wherein the stop (36) is of convex design on a side facing the end surface (34) of the receptacle (22).

30. The hose coupling (10) according to claim 19, wherein the non-return valve (20) further comprises a resilient return element (30) clamped between the bushing (26) and the valve body (28), wherein the resilient return element (30) applies a force to the valve body (28) in a direction to open the non-return valve (20).

31. The hose coupling (10) according to claim 30, wherein the resilient return element (30) resiliently pretensions the valve body (28) relative to the bushing (26) in such a way that the stop (36) abuts an end surface (34) of the receptacle (22).

32. The hose coupling (10) according to claim 19, wherein the ventilation device (18) further comprises a ventilation path (42) between the receptacle (22) and the interior of the hydrant.

33. The hose coupling (10) according to claim 32, wherein the ventilation path (42) comprises a first path (44) extending in the external flange (24) between the receptacle (22) and an external thread (14) of the hose coupling (10), and a second path (46) adjoining the first path (44), the second path (46) being formed as a recess incorporated in the external thread (14) of the hose coupling (10) in the axial direction thereof.

34. The hose coupling (10) according to claim 32, wherein an opening of the first path (44) is inserted eccentrically into the end surface (34) of the receptacle (22).

35. The hose coupling (10) according to claim 19, further comprising a backflow preventer (12).

36. Hydrant, comprising the hose coupling (10) according to claim 19, designed to reduce a difference between the pressure in the interior of the hydrant and the pressure of the outside atmosphere.

Description

[0029] In the following, the present invention is further explained with reference to exemplary embodiments shown in the drawings, wherein:

[0030] FIG. 1 shows a longitudinal sectional view through a hose coupling with a ventilation device and an installed backflow preventer;

[0031] FIG. 2 shows a longitudinal sectional view through a hose coupling with a ventilation device and an installed backflow preventer in a perspective view;

[0032] FIG. 3 shows a longitudinal sectional view through a hose coupling with a ventilation device in a perspective view; and

[0033] FIG. 4 shows an enlarged representation of the ventilation device in a sectional view.

[0034] FIGS. 1-4 each show a longitudinal sectional view through a hose coupling 10 for a hydrant (not shown) in different views. FIGS. 1 and 2 show the hose coupling 10 with a backflow preventer 12 installed, while FIGS. 3 and 4 illustrate the hose coupling 10 in a sectional view without the backflow preventer.

[0035] The hose coupling 10 can be screwed into the outlet of a hydrant (not shown) via a threaded section 14. The side of the hose coupling 10 facing the outside can be provided with claws 16, 16 by means of which a bayonet connection can be made with corresponding sections on, for example, a coupling of a fire hose (not shown). The hose coupling 10 comprises a ventilation device 18, which is designed to substantially equalize a pressure in the interior of the hydrant with respect to the external pressure. The ventilation device 18 comprises a non-return valve 20, which is accommodated in a receptacle 22, which is inserted in an outer flange 24 of the hose coupling 10. The receptacle 22 may be in the form of a blind hole having its axis oriented substantially in the radial direction of the hose coupling 10.

[0036] The non-return valve 20 comprises a bushing 26 that is at least partially insertable into the receptacle 22. The bushing 26 may be threaded into the receptacle 22, for example. The bushing 26 receives a valve body 28, which is adjustable in the axial direction of the bushing 26. Between the bushing 26 and the valve body 28, a spring-elastic return element 30 may be clamped, which may be designed as a compression spring. The return element 30 applies a force to the valve body 28, by means of which the valve body 28 is pressed against an end surface 34 of the receptacle 22.

[0037] The valve body 28 has a cylinder section 32 which is inserted at least in sections into the bushing 26. Here, the outer circumference of the cylinder section 32 is in abutment with the inner circumference of the bore of the bushing 26, so that the entire valve body 28 can be guided or adjusted in the axial direction of the bushing 26 with substantially no play. The valve body 28 is provided with a stop 36 at an end facing the end surface 34 of the receptacle 22. The stop 36 projects radially or mushroom-shaped in relation to the cylinder section 32. Here, the stop 36 is adjustable in a section of the receptacle 22 between the bushing 26 and the end surface 34 of the receptacle 22. Although not shown, the spring element 30 may be omitted. In the condition shown, the hydrant is not pressurized and air can flow from the outside environment through the ventilation device 18 into the interior of the hydrant. As a result, no negative pressure can build up in the interior of the hydrant and reliable drainage of the hydrant is thus ensured.

[0038] As soon as the hydrant is opened, the pressure in the interior of the hydrant increases and exceeds the pressure of the outside atmosphere. As soon as the difference between the pressure in the interior of the hydrant and outside atmosphere exceeds a predetermined threshold, a force is applied to the cylinder body 28 in the opposite direction, with this force exceeding the spring force applied to the cylinder section 28. This displaces the cylinder section 28 a little deeper into the bushing 26 until the stop 36 strikes directly or indirectly with its facing surface against the end surface of the bushing 26, thereby closing off the flow path, whereby the ventilation device 18 as a whole closes off the flow path.

[0039] A ring seal 38 can be provided for reliable sealing between the bushing 26, or end face of the bushing 26, and the stop 36. This ring seal 38 can be clamped in a groove 40 formed circumferentially around the cylinder section 32. The ring seal 38 may further be in surface contact with the stop 36. Further, the end face of the bushing 26 facing the stop 36 may be formed with a conically shaped sealing surface. In this embodiment, the ring seal 38 reliably seals the stop 36 circumferentially with respect to the end face of the bushing 26 facing the stop 36. In this position, a flow path through the bushing 26 is blocked or sealed (not shown). Thus, no water reaches the outside of the hydrant via the ventilation device 18.

[0040] The ventilation device further comprises a ventilation path 42, wherein the ventilation path 42 comprises a first path 44 extending in the external flange 24 between the receptacle 22 and the external thread 14 of the hose coupling 10, and a second path 46 adjoining the first path 44, the second path 46 being formed as a recess entered in the external thread 14 of the hose coupling 10 in the axial direction thereof. Although not shown, alternatively, the second path, for example, adjoining the first path 44, may be formed as a longitudinal bore within the material of the outer rim of the hose coupling 10.

[0041] As previously mentioned, when the hydrant is in the pressure-free condition, a fluid connection opens between the exterior and the interior of the hydrant, allowing ventilation into the interior of the hydrant. This allows outside air to flow through the bore of the bushing 26 along the cylinder body 28 and into the receptacle 22 via the opened annular gap between the bushing 26 and the stop 36. From the receptacle 22, the outside air continues to flow into the interior of the hydrant via the first path 44 and second path 46.

[0042] As soon as the difference between the pressure in the interior of the hydrant and the outside atmosphere exceeds a predetermined threshold value, e.g. by opening the hydrant, the non-return valve 20 closes and this connection is blocked. Thus, no water penetrates to the outside via the ventilation device 18.

[0043] In summary, the non-return valve 20 assumes two states, namely a first state (closing state) in which the stop 36 abuts and seals against the end face of the bushing 26 facing the stop 36 via the ring seal 38, and a second state (opening state) in which the stop 36 abuts with its opposite side against the end surface 34 of the receptacle 22. The first state here is a state in which a difference between the pressure in the interior of the hydrant and outside pressure exceeds a predetermined threshold. The second state is a state in which there is substantially equal pressure between the pressure in the interior of the hydrant and outside atmosphere, or the difference between the pressure in the interior of the hydrant and outside pressure falls below the predetermined threshold value.

[0044] That side of the stop 36 which faces the end surface 34 of the receptacle 22 may be provided with a substantially centrally disposed projection. In the embodiment shown in the figures, the stop is of convex design on the side concerned. In the opened state of the non-return valve 20, the stop 36 thus strikes with its most protruding (axially central) section against the end surface 34 of the receptacle 22. Furthermore, the opening or entrance of the first path 44 is entered eccentrically into the end surface 34 of the receptacle 22. The convex shape of the stop 36 in cooperation with the opening of the first path 44 entered off-center in the end surface 34 of the receptacle 22 prevents this opening from being closed by the stop 36 in the open state of the non-return valve 20, i.e., even if the stop 36 strikes against the end surface 34 of the receptacle 22. In summary, the stop 36 strikes against the end surface 34 of the receptacle 22 with its most protruding (axially central) section, leaving the opening of the first path 44, or its entrance, free. Thus, reliable ventilation of the hydrant is enabled.

[0045] As previously described, the hose coupling 10 may be provided with the backflow preventer 12 to prevent, for example, water from, for example, a fire hose from being forced back and possibly foreign matter from entering the interior of the hydrant. The backflow preventer 12 can be bridged by means of the ventilation device 18. Thus, despite the provision of the backflow pre-venter 12, equalization can be established between the pressure in the interior of the hydrant and the pressure of the outside atmosphere. As soon as the hydrant is pressurized, e.g. by opening the hydrant, the non-return valve 20 closes and water is thus prevented from flowing to the outside via the ventilation device 18.