GB2082289A

GB2082289A - Valve

Info

Publication number: GB2082289A
Application number: GB8121054A
Authority: GB
Original assignee: Gustav F Gerdts KG
Current assignee: Gustav F Gerdts KG
Priority date: 1980-08-14
Filing date: 1981-07-08
Publication date: 1982-03-03
Also published as: ES8301344A1; DE3030747A1; FR2488672A1; GB2082289B; ES504020A0; DE3030747C2; FR2488672B1

Abstract

A valve has a valve spindle (4) carrying on its end, inside the valve casing (2) a closure member (1) and surrounded on its end outside the casing by a valve spring (9) acting on the valve spindle (4). A rocking lever (17) is provided for adjusting the closure member (1) and a bearing member for the rocking lever (17) is held on the valve casing (2). The bearing member comprises a U- shaped member (11) which is arched over the valve spindle (4) and valve spring (9) and is held by its two ends on the valve casing (2). The rocking lever (17) has a fork-like end on the casing side and its two fork arms (18) project laterally between the valve spring (9) and the sides (12) of the U- shaped member (11). A bearing bolt (24) for the fork arms (18) is held in an offset manner with respect to the valve spindle (4) in the said sides (12) of the U-shaped member (11). The fork arms (18) co-operate with a drive member (10) attached to the outer end of the spindle (4), the spring (9) being positioned between the drive member (10) and the valve casing (2). <IMAGE>

Description

SPECIFICATION Valve This invention relates to a valve of the type having a valve spindle carrying on its end, located within the valve casing, a closure member and surrounded on its end outside the casing by a valve spring acting on the valve spindle with a rocking lever for adjusting the stroke of the closure member and a bearing member for the rocking lever held on the valve casing.

Such fittings which are also called quick-action stop valves are used inter alia as blow-off valves on boilers. In order to be able to fit the valve at a particularly advantageous point for foot or hand operation a limited overall height of the valve is particularly advantageous.

The present invention aims to provide a valve of the aforementioned type, whose actuating device has a limited overall height, comprises few inexpensive components and is easy to assemble.

According to the invention, there is provided a valve having a casing; a valve spindle carrying on its end, inside the casing, a closure member and surrounded on its end outside the casing by a valve spring acting on the valve spindle; a rocking lever for adjusting the stroke of the closure member and a bearing member for the rocking lever held on the valve casing; wherein the bearing member comprises a U-shaped member which is arched over the valve spindle and valve spring and is held by its two ends on the valve casing, the rocking lever has a fork-like end on the casing side and its two fork arms project laterally between the valve spring and the sides of the U-shaped member and a bearing bolt for the fork arms is held in an offset manner with respect to the valve spindle in the said sides of the U-shaped member.

The construction of the bearing member as a Ushaped member gives a particularly simple component which presents no problems from the manufacturing standpoint and which also offers good access from two sides to the valve spindle and the parts of the actuating device. Owing to the fact that the rocking lever is mounted laterally on the U-shaped member alongside the valve spring, said lever involves no additional height on the part of the said member. Therefore the overall height can be significantly reduced.

Preferably, the sides of the U-shaped member are adapted to receive means for locking the rocking lever engaging on the fork arms.

According to a preferred embodiment, the locking means comprise a guide pin and the sides of the U-shaped member have seating bores for the guide pin in the vicinity of the fork arms and at right angles to the pivoting direction thereof.

The sides of the U-shaped member are desirably constructed in rod-like manner and in the vicinity of the fork arms have on one side widened portions in which are arranged the seating bores. The sides of the U-shaped member may also have further widened portions in the vicinity of the fork arms in which is held the bearing bolt. By means of these measures, the Ushaped member has a minimum material volume and is therefore light and inexpensive. There is also a further positive influence on the accessibility of the individual parts of the actuating device.

Preferably, the sides of the U-shaped member carry on the inside swing limit stops for the fork arms. This prevents e.g. a disadvantageous locking closed of the valve spring.

If the exit point of the valve spindle from the valve casing is sealed by a stuffing box instead of a bellows or e.g. an O-ring, it is advantageous to use the valve spring as a pressure member for the packing. This leads to an automatic resetting of the stuffing box and also the constructional expenditure and necessary overall height are reduced.

As the pressure acting on the packing is determined by the valve spring and as the permitted or acceptable force for valve operation is decisive for the design thereof, it may occur under unfavourable circumstances, e.g. in the case of water shocks or when the valve is pressure tested with a very high test pressure that the packing is forced out of the stuffing box bearing bore counter to the action of the valve spring, so that a leak occurs at this point.

According to a preferred embodiment of the invention, the casing-side end of the valve spring is supported on a packing for the valve spindle, and a support plate is provided between the valve spring and the packing, the supported plate having a central passage opening for the valve spindle and the sides of the U-shaped member having stroke limit stops for the support plate in front of the end face of said plate remote from the packing. This arrangement provides a reliable remedy in that the forcing out of the packing is prevented by the U-shaped member, this also applying if the valve spring fractures.

The support plate desirably comprises a circular disc which offers the advantage that commercially available, inexpensive parts can be used for the support plate, e.g. a cup spring. Furthermore, for ensuring a permanent support readiness it also requires no protection against torsion, unlike in the case of a strip-like support plate.

A pressure bush may be provided between the support plate and packing, the pressure bush having a spigot engaging into the passage opening of the support plate, whilst between the latter and the stroke limit stops an axial clearance at least equal to the height of the spigot is provided in the fitted state. The pressure bush for the packing also serves for the centering of the circular support plate, whilst it is still possible to laterally insert the plate into its fitting position.

The U-shaped member is desirably provided at its ends with a cover for the valve casing. The casing cover with the spindle passage and the associated packing, together with the U-shaped member and the actuating device can then form a single constructional group.

The web of the U-shaped member may have a central connecting bore for a servomotor. This arrangement provides the possibility of converting the hand or foot-operated valve into a motor operated valve by merely adding parts. The rocking lever is then used for emergency operation if the drive energy for the servomotorfails.

The invention will now be further described, by way of example, with reference to the drawings, in which: Fig. 1 is a longitudinal section through one embodiment of a valve according to the invention; Fig. 2 is a plan view of the valve shown in Fig.

1; Fig. 3 is a side view of the valve shown in Fig.

1;and Fig. 4 shows another embodiment of a valve according to the invention provided with a servomotor.

Referring to the drawings, the valve comprises a closure member 3 which cooperates with a valve seat 1 in a valve casing 2. The valve spindle 4 of the closure member projects through a cover 5 out of the valve casing 2. Within the cover 5, the valve spindle 4 is surrounded by a multilayer packing 6. One end of a valve spring 9 exerts a compressing action on the packing 6 via a pressure bush 7, as well as a support plate 8 comprising a cup spring which has a central passage opening for the valve spindle 4. A driving cap 10 fixed to the valve spindle 4 engages over the other end of the valve spring 9.

A U-shaped member 11 arching over the valve spindle 4 and valve spring 9 is integrally connected at its two ends to the cover 5. The web 14 of the U-shaped member connecting the two U-shaped member sides 12, 13 carries in a central connecting bore 1 5 a guide bush 1 6 (Figs. 1 to 3) for the free end of the valve spindle.

On the casing side a rocking lever 1 7 has a fork-like end, whose two fork arms 1 8, 1 9 project laterally between the driving cap 10 with the valve spring 9 and the two sides 12, 13. The fork arms 18, 19 have driving pins 20 engaging in lateral recesses 21 in the driving cap 10.

In the vicinity of the fork arms 18, 19, the sides 12, 13, constructed in narrow, rod-like manner at their ends, have lateral widened portions 22, 23. A bearing bolt 24 for the two fork arms 1 8, 1 9 is held by its two ends in the widened portions 22.

The other widened portions 23 directed oppositely to the first-mentioned portions 22 have in each case two seating bores 25, 26 into which can be inserted a guide pin 27.

For limiting the maximum opening path of the rocking lever 17, the U-shaped member sides 12, 13 have on the inside swing limit stops 28 and are also provided there with stroke limit stops 29 for the support plate 8.

The assembly of the individual parts in the U shaped member 11 with the cover 5 presents no problems owing to the good lateral accessibility.

Firstly, the packing 6 is placed in the cover 5 and, if necessary, pressed forward. This is followed by the insertion of the pressure bush 7. A verticai spacing corresponding at least to the overall height of the support plate 8 is left between the end face of the pressure bush 7 and the stroke stops 29, so that the plate 8 can be inserted from the side between the stroke stops 29 and pressure bush 7 and can be mounted on a spigot 30 on the bush 7. The valve spring 9 with the fitted driving cap 10 is then inserted in the member 11. After fitting the valve spindle 4 and its guide bush 16, it is merely necessary to place the rocking lever 1 Z with its fork arms 1 8, 1 9 laterally between the sides 12, 1 3 and the driving cap 10 until the driving pins 20 engage in the recesses 21 of the driving cap 10.Finally, the bearing bolt 24 is placed in the fork arms 1 8, 19 and the U-shaped member sides 12, 13. Owing to the fact that the arms 1 8, 1 9 are located laterally alongside the valve spring 9, the overall height of the member 11 can be kept particularly small.

The valve is operated by pivoting the rocking lever 1 7 and by inserting the guide pin 27 in seating bores 25 or 26, the rocking lever 1 7 and with it the closure member 3 can be locked in the closed or open position.

If such high pressures occur in the valve casing 2 that the packing 9 is pressed upwards counter to the action of the valve spring 9, the support plate 8 engages against the stroke limit stops 29 and prevents the pressure bush 7 from being forced completely and the packing 6 from being forced partly out of the cover 5 and permitting a leak to form.

In the construction according to Fig. 4, a bearing bush 31 is inserted and held in the connecting bore 1 5 of the web 14. The bush 31 carries pressure-operated servomotor 32 comprising two wall parts 33, 34, an intermediately secured lifting diaphragm 35 and a ram 36 operated by the same. The latter is mounted in the bearing bush 31 and acts on the free end of the valve spindle.

Thus, by merely replacing the guide bush 1 6 by the servomotor 32, the manually operated valve can be converted into a motor-driven valve with emergency manual operation with minimum expenditure.

Claims

1. A valve having a casing; a valve spindle carrying on its end, inside the casing, a closure member and surrounded on its end outside the casing by a valve spring acting on the valve spindle; a rocking lever for adjusting the stroke of the closure member and a bearing member for the rocking lever held on the valve casing; wherein the bearing member comprises a U-shaped member which is arched over the valve spindle and valve -- spring and is held by its two ends on the valve casing, the rocking lever has a fork-like end on the casing side and its two fork arms project laterally between the valve spring and the sides of the Ushaped member and a bearing bolt for the fork arms is held in an offset manner with respect to the valve spindle in the said sides of the U-shaped member.

2. A valve according to claim 1, wherein the sides of the U-shaped member are adapted to receive means for locking the rocking lever engaging on the fork arms.

3. A valve according to claim 2, wherein the locking means comprise a guide pin and the sides of the U-shaped member having seating bores for the guide pin in the vicinity of the fork arms and at right angles to the pivoting direction thereof.

4. A valve according to claim 3, wherein the sides of the U-shaped member are constructed in rod-like manner and in the vicinity of the fork arms have on one side widened portions in which are arranged the seating bores.

5. A valve according to any preceding claim, wherein the sides of the U-shaped member have a narrow rod-like construction and in the vicinity of the fork arms have widened portions on one side in which is held the bearing bolt.

6. A valve according to any preceding claim, wherein the sides of the U-shaped member carry on the inside swing limit stops for the fork arms.

7. A valve according to any preceding claim, wherein the casing-side end of the valve spring is supported on a packing for the valve spindle, and wherein a support plate is provided between the valve spring and the packing, the support plate having a central passage opening for the valve spindle and the sides of the U-shaped member having stroke limit stops for the support plate in front of the end face of said plate remote from the packing.

8. A valve according to claim 7, wherein the support plate comprises a circular disc.

9. A valve according to claim 7 or claim 8, wherein a pressure bush is provided between the support plate and packing, the pressure bush having a spigot engaging into the passage opening of the support plate, whilst between the latter and the stroke limit stops an axial clearance at least equal to the height of the spigot is provided in the fitted state.

10. A valve according to any preceding claim, wherein the U-shaped member is provided at its ends with a cover for the valve casing.

11. A valve according to any preceding claim, wherein the web of the U-shaped member web connecting the U-shaped member sides has a guide for the free end of the valve spindle.

12. A valve according to any preceding claim, wherein the web of the U-shaped member has a central connecting bore for a servomotor.

13. A valve according to claim 12, wherein a bearing bush is held in the connecting bore and outside the web carries a servomotor in which is mounted a lifting ram arranged to act on the valve spindle.

14. A valve substantially as described herein with reference to the drawings.