Device for a valve

Abstract

 A device for a valve in an outlet duct (3b) is disclosed, the valve comprising at least one closing member (5) for closing off the outlet duct (3b) and the closing member (5) being moveable between a closed position and an open position. The device comprises means for damping the closing speed of the closing member. One object is to prevent loud rattling noises in the valve. A further object is to reduce material stresses on said valve. An operating member is also disclosed, which comprises a turning element (10) designed to perform a rotational movement. The operating member comprises means for damping the rotational movement. The object is to afford increased resistance to turning, which gives a better feel. A further object is to reduce the material stresses on said operating member.

Description

TECHNICAL FIELD

[0001] The invention relates to a device for a valve in an outlet duct according to the pre-characterizing part of claim 1. The invention also relates to an operating member according to the pre-characterizing part of claim 18.

BACKGROUND OF THE INVENTION

[0002] Valves with an opening and closing valve cover are used in ventilation systems. When the valve cover is open, air can be emitted through an outlet duct.

[0003] In the use of a ventilation valve, in which the valve cover in an oscillating movement about an axis running transversely to the longitudinal direction of the outlet duct is opened and closed like a door, on closing of the valve a pressure wave occurs in the outlet duct which is then reflected and opens the valve cover again, whereupon it is closed again, a new pressure wave occurs, which is reflected, and the valve cover is opened again, etc. As a result, the valve cover of the valve, either temporarily or continuously, slams to and fro against an end flange contained within the valve. A conventional solution to this problem is to use a closing device for closing the valve, comprising a strong spring or the like, which closes the valve cover with a force sufficient to withstand the said pressure wave. This solution using a strong spring to close the valve cover is also employed on sliding valve covers. A problem with this solution is that the strong closing force causes a loud rattling noise when it closes again. A further disadvantage with the said solution is that the strong closing force causes undue material stresses on the valve.

[0004] Natural draught ventilation relies on the fact that warm air rises, so that the difference between outdoor and indoor temperature determines the quality of the ventilation achieved. Cold weather gives good ventilation, but then a counter-draught also occurs in the outlet duct in which cold air and even frost are entrained so that so-called cold creep occurs. In order to safeguard against cold creep, non-return valves are used (also referred to as cold creep protection) which, by means of a valve cover that is capable of swivelling from a horizontal closed position into a vertical open position, only allow air to escape from the outlet pipe but prevent cold creep. One problem with non-return valves is that they can keep oscillating between the open and closed position, which causes loud rattling noises. A further problem are the undue material stresses that occur when the valve cover slams to and fro.

SUMMARY OF THE INVENTION

[0005] An object of the present invention is to prevent high noise levels in a valve. A further object of the present invention is to increase the service life of a valve and other parts.

[0006] In order to achieve these objects, a device for a valve of the said generic type is characterized in that it comprises means for damping the closing speed of the closing member. The advantage of this solution is that a reduced closing speed is obtained, so that the contact between the closing member and the end flange of the valve is less violent, which means that loud rattling noises are prevented. A further advantage is that the material stresses are reduced, with the result that the service life of the valve and other parts is substantially increased.

[0007] The means of damping the closing speed preferably comprises a viscous, long-life oil applied in a gap between a fixed part and a moving part connected to the closing member. It has been shown that oil having the aforementioned characteristics is eminently suitable for this purpose.

[0008] The moving part is preferably designed to perform a rotational movement about an axis of rotation. It has proved advantageous to have the moving part perform a rotational movement about an axis of rotation, since it can then be readily adapted to existing solutions.

[0009] The fixed part and the moving part preferably each have an essentially cylindrical surface concentric with the axis of rotation, said surfaces being opposed to one another and the viscous, long-life oil preferably being applied axially in a gap between the cylindrical surfaces. The advantage with this solution is that when the surface of the moving part is rotated against the surface of the fixed part, the viscous, long-life oil gives rise to a shear force acting counter to the closing direction, so that the closing speed of the closing member is damped.

[0010] The moving part is preferably to a substantial extent inserted into the fixed part. The advantage of arranging the fixed part and the moving part relative to one another in this way is that it results in a simple design construction.

[0011] The fixed part and the moving part preferably each have an essentially plane surface aligned radially in relation to the axis of rotation, said surfaces being opposed to one another and the viscous, long-life oil preferably being applied radially between the plane surfaces. The advantage of this solution is that when the surface of the moving part is rotated against the surface of the fixed part, the viscous, long-life oil gives rise to a shear force acting counter to the closing direction, so that the closing speed of the closing member is damped.

[0012] The valve is preferably designed to regulate the air flow from an outlet opening in the outlet duct, the closing member being designed to be closed by means of a spring member and being designed to be operated by an operating member comprising the fixed part and the moving part. This embodiment has proved particularly advantageous in the case of kitchen ventilation. One advantage is that the damping means is easily accessible, since the means is situated in the operating member and this is generally easily accessible.

[0013] The fixed part and the moving part are preferably arranged in an opening between the outside and inside of a fan housing. One advantage of this arrangement is that the device is easy to fit to existing kitchen range hoods, since only the turning element needs to be removed.

[0014] In a second embodiment the fixed part and the moving part are arranged inside the control element. One advantage with this arrangement is that the device does not take up any additional space. This embodiment may be used, for preference, in new production.

[0015] In a third embodiment the fixed part and the moving part are arranged between the control element and the valve. The arrangement of the fixed part and the moving part is done for practical and installation reasons and is not dependent upon the design of the operating member, and the design of the valve and this embodiment may be preferable in certain design types.

[0016] In a fourth embodiment the fixed part and the moving part are arranged on the axis of rotation of the closing member. One advantage with this solution is that the damping force occurs in close proximity to that which is being damped, which reduces the risk of excessive play.

[0017] The valve is preferably a non-return valve. This solution may be of particular advantage in the case of natural draught ventilation.

[0018] The non-return valve preferably comprises two closing members, together with two fixed parts and two moving parts, each fixed part and each moving part being arranged on opposite sides of the axis of rotation of each closing member. The advantage with this solution is that, in a non-return valve having two closing members, the closing speed of each closing member is moderated.

[0019] The non-return valve is preferably located in the outlet duct. This arrangement is advantageous in preventing cold creep.

[0020] The invention also provides an operating member of the aforementioned generic type, characterized by means for damping the rotational movement.

DESCRIPTION OF THE DRAWINGS

[0021] The invention will be described in more detail below with the aid of drawings attached, in which:

Fig. 1 shows a schematic exploded sketch of a part of a fan housing, a valve, an outlet duct and an operating member according to a first embodiment of the present invention,

Fig. 2 shows a perspective view of a valve according to Fig. 1,

Fig. 3 shows a cross-section through an operating member according to the first embodiment of the invention according to Fig. 1,

Fig. 4 shows a cross-section through an operating member according to a second embodiment of the invention,

Fig. 5 shows a cross-section through an operating member according to a third embodiment of the invention,

Fig. 6 shows a plan view of a non-return valve according to a fourth embodiment of the invention,

Fig. 7 shows a cross-section through a part of the non-return valve according to the fourth embodiment of the invention,

Fig. 8 shows a schematic sketch of a shock-absorber arranged in a slide valve, and

Fig. 9 shows a schematic exploded sketch of a part of a fan housing, a slide valve, an outlet duct and an operating member according to the first embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0022] As will be seen from Fig. 2, a valve 2 comprises a valve cover 5, and a pipe stub 7, which carries the valve cover 5. Such a valve is shown in EP 0 422 316 which is hereby incorporated by virtue of this reference. The valve cover 5 is pivotally connected by way of a hinge connection to an end flange 8 of the pipe stub 7. The valve cover 5 is furthermore designed so that in the closed position of the valve 2 it covers the opening of the pipe stub 7 in that an outer peripheral part comes to bear against an inner part of the annular surface of the end flange 8. The valve 2 is suitably fixed in its entirety to a fan housing 1, Fig. 1, with the unflanged end of the pipe stub 7 connected to an outlet duct 3b of a central ventilation system. The term fan housing relates to all types of devices in kitchen ventilation including kitchen range hoods. With the valve 2 in an open position, air is led off from the inside of the fan housing 1 through the pipe stub 7 to the outlet duct 3b.

[0023] As will be seen from Fig. 1, 3 and 9, the valve cover is designed to be opened by means of an operating member 9 comprising a turning element 10, a rod 11, a fixed part 12, a moving part 13, and a control element 14. As will be seen from Fig. 1 and 9, the turning element 10, the rod 11, the fixed part 12, the moving part 13 and the control element 14 are arranged, essentially concentrically, around an axis of rotation 17. The turning element 10 is fitted in an opening on the outside 1' of the fan housing 1, the fixed part 12 and the moving part 13 are located in the opening essentially between the outside 1' and the inside 1'' of the fan housing 1, the control element 14 is fixed to the inside 1'' of the fan housing 1, and the rod 11 is placed centrally right through the control element 14 and extends through the fixed part 12 and the moving part 13 to the opening in the outside 1' of the fan housing 1. The turning element 10 is connected to the moving part 13, the rod 11 is concentrically connected to the turning element 10 and via a linkage is connected to the valve cover 5, and the control element 14 is connected to the rod 11. As will be seen from Fig. 1, the fixed part 12 and the moving part 13 each have a cylindrical surface 18,19 essentially concentric with the axis of rotation 17 and in opposition to one another, the moving part 13 being substantially inserted into the fixed part 12 and a film of viscous, long-life oil being applied axially in a gap between the cylindrical surfaces 18, 19. Alternatively, the fixed part 12 may be inserted into the moving part 13. The control element 14 comprises a timer control and a spring member 15, such as a coil spring, although other types of spring may be used.

[0024] In kitchen range ventilation, the valve cover 5 is opened by manually turning the turning element 10 (clockwise), the rod 11 and the moving part 13 being turned synchronously with the turning element 10 so that, via a linkage between the rod 11 and the valve cover 5, the valve cover 5 is opened like a door in a swivelling movement about the axis of rotation 17, which runs transversely to the longitudinal direction of the outlet duct 3b. By means of the timer control, the control element 14 controls the position of the valve cover 5 in such a way that the valve cover 5, via a linkage, is opened into an open position by manually turning the turning element 10 until the timer is switched on, thereby tensioning the spring member 15. The desired time for which the valve cover 5 will be in the open position is adjusted by the timer by turning the turning element 10 to the desired position. When the set time has elapsed, the timer shuts off, with the result that the spring member 15 closes the valve cover 5 under spring force. The viscous, long-life oil that is applied axially between the cylindrical surfaces 18, 19 gives rise to increased resistance between the cylindrical surfaces 18, 19, when turning the moving part 13, especially when closing the valve cover 5. The viscous, long-life oil is of a quality such that under slow movements it generates little resistance and under rapid movements it generates great resistance. When the valve cover 5 is closed with a spring force produced by the spring member 15, the viscous, long-life oil applied axially between the cylindrical surfaces 18, 19 gives rise to a shear force opposed to the spring force as the moving part 13 rotates inside the fixed part 12, thereby damping the closing speed of the valve cover 5. These characteristics give rise to such a strong resistance that the closing speed of the valve cover 5 is damped to a speed conducive to the purpose, so that loud rattling noises are avoided and material stresses are reduced, but the spring force that keeps the valve cover 5 closed is maintained. According to a preferred embodiment the viscous, long-life oil is of the type commercially available under the designation adhering chain oil, adhesive chain oil or wax oil, which is normally used for high-speed drive chains. Other types of chemical compositions having similar characteristics may also be used.

[0025] According to a second embodiment, shown in Fig. 4, the fixed part 12 and the moving part 13 are located inside the control element 14. The fixed part 12 and the moving part 13 each have an essentially plane surface 18, 19 aligned radially in relation to the axis of rotation 17, said surfaces being opposed to one another and the viscous, long-life oil being applied radially between the plane surfaces 18, 19. As in the aforementioned embodiment, the viscous, long-life oil that is applied radially between the plane surfaces 18, 19 correspondingly gives rise to increased resistance between the plane surfaces 18, 19, when turning the moving part 13, especially when closing the valve cover 5. When the valve cover 5 is closed under the spring force generated by the spring member 15, the viscous, long-life oil that is applied radially between the plane surfaces 18, 19 gives rise to a shear force opposed to the spring force as the plane surface 19 of the moving part 13 rotates against the plane surface 18 of the fixed part 12, thereby damping the closing speed of the valve cover 5, so that loud rattling noises are avoided and material stresses are reduced.

[0026] According to a third embodiment, shown in Fig. 5, the fixed part 12 and the moving part 13 are located between the control element 14 and the valve 2. The fixed part 12 and the moving part 13 each have an essentially cylindrical surface 18, 19 concentric with the axis of rotation 17, said surfaces being opposed to one another, the moving part 13 is substantially inserted into the fixed part 12 and a film of viscous, long-life oil is applied axially in a gap between the cylindrical surfaces 18, 19. As in the aforementioned embodiments, the viscous, long-life oil that is applied axially between the cylindrical surfaces 18, 19 correspondingly gives rise to increased resistance between the cylindrical surfaces 18, 19, when turning the moving part 13, especially when closing the valve cover 5. When the valve cover 5 is closed under the spring force generated by the spring member 15, the viscous, long-life oil that is applied axially between the cylindrical surfaces 18, 19 gives rise to a shear force opposed to the spring force as the moving part 13 rotates inside the fixed part 12, thereby damping the closing speed of the valve cover 5, so that loud rattling noises are avoided and material stresses are reduced.

[0027] An alternative to the third embodiment is to locate the fixed part 12 and the moving part 13 on the rod 11 between the control element 14 and the valve 2, instead of locating said parts by the control element. A further alternative to the third embodiment is to connect the fixed part 12 and the moving part 13 to the axis about which the swivelling valve cover is pivotally connected instead of locating said parts by the control element or on the rod.

[0028] In a fourth embodiment the valve 2 consists of a non-return valve according to Fig. 6, which is used in a housing with natural draught and relying on the fact that warm air rises, so that the difference between the outdoor and indoor temperature determined the quality of the ventilation obtained. Cold weather gives good ventilation, but then a counter-draught also occurs in the outlet duct 3b in which cold air and even frost are entrained so that so-called cold creep occurs. The non-return valve is used for protection against cold creep. The non-return valve is normally located inside the outlet duct 3b, but can also be located in connection with the outlet duct. The non-return valve has at least one valve cover 5, but preferably two valve covers 5, as shown in Fig. 6, which are each capable of pivoting about a separate axis of rotation 17 from a horizontal closed position into a vertical open position. The non-return valve only allows air to escape from the outlet pipe but prevents cold creep. As will be seen from Fig. 6 and 7, in each of the valves 2, a fixed part 12 and a moving part 13 each have essentially cylindrical surfaces 18, 19 concentric with the axis of rotation 17, said surfaces being opposed to one another. The pairs comprising a fixed part 12 and a moving part 13 are arranged on opposite sides of the non-return valve on respective axes of rotation 17. Each moving part 13 is substantially inserted into each fixed part 12, and the viscous, long-life oil is applied axially in a gap between the cylindrical surfaces 18, 19. As in the aforementioned embodiments, the viscous, long-life oil that is applied axially between the cylindrical surfaces 18, 19 correspondingly gives rise to increased resistance between the surface 18 of the fixed part 12 and the surface 19 of the moving part 13 when the moving part 13 is turned, thereby damping the closing speed of the valve cover 5, so that loud rattling noises are avoided and material stresses are reduced.

[0029] In a further embodiment a valve operating member is used comprising a turning element 10 mechanically connected to the valve cover 5 in order to control the latter. The turning element 10 also constitutes a part of a rotary flow adjuster for controlling an electric fan. The rotary flow adjuster may have both continuously variable adjustment and be adjusted in various stages. The sensitivity when turning a continuously variable flow adjuster is "coarse" and comparable to the frequency adjustment dial on a cheap radio. In the stepped rotary flow adjuster the point of engagement registers very abruptly. It is desirable to achieve a certain inertia when turning, a "better feel". It has been shown that the viscous, long-life oil is also suited to damping the point of engagement in flow adjusters that are adjusted in different stages as these stages register, and to providing a desirable inertia when turning, both in continuously variable adjustment and with stepped adjustment.

[0030] Various embodiments have been described above, in which the means of damping the closing speed of the valve cover consists of a viscous, long-life oil, but any other damping elements are also feasible. For example, the means may consist of a gear arrangement located on the valve in such a way that it has a transmission ratio which damps the closing speed of the valve cover. The transmission ratio means that the torque on the axis of rotation 17 of the valve due to the spring force is reduced, with the result that the closing speed is reduced. Alternatively, in the case of the slide valve as shown in Fig. 8, a shock absorber, for example, may be used in which a piston damps the closing speed of the valve cover.

Claims

1. Device for a valve in an outlet duct (3b), the valve comprising at least one closing member (5) for closing off the outlet duct (3b) and the closing member (5) being moveable between a closed position and an open position, characterized by means for damping the closing speed of the closing member (5).

2. Device according to Claim 1, characterized in that said means comprises a viscous, long-life oil applied between at least one fixed part (12) and at least one moving part (13) connected to the closing member (5).

3. Device according to Claim 2, characterized in that the moving part (13) is designed to perform a rotational movement about an axis of rotation (17).

4. Device according to Claim 3, characterized in that the fixed part (12) and the moving part (13) each have an essentially cylindrical surface (18, 19) concentric with the axis of rotation (17), said surfaces being opposed to one another, and in that the viscous, long-life oil is applied axially in a gap between the cylindrical surfaces (18, 19).

5. Device according to Claim 4, characterized in that the moving part (13) is substantially inserted into the fixed part (12).

6. Device according to Claim 3, characterized in that the fixed part (12) and the moving part (13) each have an essentially plane surface (18, 19) aligned radially in relation to the axis of rotation (17), said surfaces (18, 19) being opposed to one another, and in that the viscous, long-life oil is applied radially between the plane surfaces (18, 19).

7. Device according to any one of Claims 2 to 6, characterized in that the valve (2) is designed to regulate the air flow from an outlet opening (3a) in the outlet duct (3b), in that the closing member (5) is designed to be closed by means of a spring member (15) and designed to be operated by an operating member (9) comprising the fixed part (12) and the moving part (13).

8. Device according to Claim 7, characterized in that the operating member (9) comprises a turning element (10) connected to the moving part (13), a rod (11) connected to the turning element and connected via a linkage to the closing member (5), and a control element (14) for controlling the position of the closing member (5).

9. Device according to any one of Claims 2 to 8, characterized in that the fixed part (12) and the moving part (13) are arranged in an opening between the outside (1') and inside (1'') of a fan housing (1).

10. Device according to Claim 8, characterized in that the fixed part (12) and the moving part (13) are arranged inside the control element (14).

11. Device according to Claim 8, characterized in that the fixed part (12) and the moving part (13) are arranged between the control element (14) and the valve (2).

12. Device according to any one of Claims 3 to 8, characterized in that the fixed part (12) and the moving part (13) are arranged on the axis of rotation (17) of the closing member (5).

13. Device according to any one of Claims 1 to 12, characterized in that the closing member (5) is capable of swivelling between the closed and the open position.

14. Device according to any one of Claims 1, 2, 3, 4, 5, 6, 12 or 13, characterized in that the valve (2) is a non-return valve.

15. Device according to Claim 14, characterized in that the non-return valve comprises two closing members (5), at least one of these having a fixed part (12) and a moving part (13) connected to the closing member, these parts being arranged on an axis of rotation (17) of the closing member (5).

16. Device according to Claim 15, characterized in that a fixed part (12) and a moving part (13) connected to each closing member (5) are arranged by each closing member (5).

17. Device according to any one of Claims 14 to 16, characterized in that the non-return valve is located in the outlet duct (3b).

18. Operating member comprising a turning element (10) designed to perform a rotational movement, characterized by means for damping the rotational movement.

19. Operating member according to Claim 18, characterized in that said means comprise a viscous, long-life oil applied between at least one fixed part (12) and at least one moving part (13) connected to the turning element (10).

20. Operating member according to Claim 19, characterized in that the moving part (13) is designed to perform a rotational movement about an axis of rotation (17).

21. Operating member according to Claim 20, characterized in that the fixed part (12) and the moving part (13) each have an essentially cylindrical surface (18, 19) concentric with the axis of rotation (17), said surfaces being opposed to one another, and that the viscous, long-life oil is applied axially in a gap between the cylindrical surfaces (18, 19).

22. Operating member according to Claim 20, characterized in that the fixed part (12) and the moving part (13) each have an essentially plane surface (18, 19) aligned radially in relation to the axis of rotation (17), said surfaces (18, 19) being opposed to one another, and in that the viscous, long-life oil is applied radially between the plane surfaces (18, 19).

23. Operating member according to any one of Claims 18 to 22, characterized in that the operating member comprises a timer control and a spring member (15).

24. Operating member according to any one of Claims 18 to 22, characterized in that the operating member comprises a rotary flow adjuster.

Drawing