GB2095793A - Valves - Google Patents

Abstract

An iris diaphragm valve which is of simple construction and which can be economically manufactured has a flexible sleeve (10) having opposite ends mounted on first and second rings (11 and 12). A third ring (15) surrounds the second ring (12) and is secured thereto by bars (14). Bearing bushes (19) which are secured to a mounting flange around an opening in the base of a hopper, are engaged with U-shaped mountings 13 secured to the first ring (11). The third ring (15) engages bushes 19 and is rotatable relative thereto with ring (12). The second ring (12) is rotated relative to the first ring (11) to open and close the valve by an operating handle (16) extending outwardly thereof. <IMAGE>

Description

SPECIFICATION Valves This invention relates to valves and is more particularly concerned with so-called iris diaphragm valves wherein a flexible sleeve is employed and means are provided for effecting relative rotation of portions of the sleeve.

Such valves are typically used for controlling the flow of particulate material from a hopper or other container.

In a known form of iris diaphragm valve, the flexible sleeve is secured at each end to a circumferential ring. The ring at one end of the sleeve is secured by means of a first clamping ring in a recess in a first casting having an annular mounting flange which is apertured to enable it to be bolted to a corresponding flange around the lower outlet of the hopper or other container. The ring at the other end of the flexible sleeve is disposed in a recess in a second casting which is mounted on the underside of the first casting so as to be rotatable relative thereto. The clamping ring at said opposite end of the sleeve is rotatable with the second casting so that, upon rotation of the latter relative to the first casting, for example by hand, the sleeve can be twisted or untwisted so as to close or open, respectively, the valve.

Whilst the above described type of iris diaphragm valve operate extremely effectively and enable a very precise controi of flow of material from the hopper or other container, it is relatively expensive, particularly compared with a simple sliding plate valve. Additionally, it becomes impracticable to use the above-described iris diaphragm valves for hoppers or other containers having very large diameter outlets because the castings become prohibitively expensive.

It is therefore an object of the present invention to provide an improved form of iris diaphragm valve which is of relatively simple construction and which can be manufactured economically even for large diameter applications.

According to the present invention, there is provided a valve comprising a flexible sleeve having first and second axially spaced sleeve portions, first and second rings to which the first and second sleeve portions are respectively secured, mounting means secured to and extending outwardly from the first ring to enable the latter to be mounted via bolts or the like on a flange or the like around an opening through which the flow of material is to be controlled in use by the valve, a mounting and guide means disposed outwardly of the second ring and connected thereto, and bearing means which are engaged by said mounting and guide means and fixed relative to the first ring and/or to the flange or the like in use, said mounting and guide means being movable relative to the bearing means so as to enable relative rotation between the first and second rings for valve opening and closing purposes.

The valve may be operated manually by providing a suitable operating lever or the like or it may be power operated.

In a convenient embodiment, the mounting and guide means comprises a third ring which is spaced outwardly of the second ring and connected thereto by generally radially extending arms secured to the second and third rings. The bearing means preferably take the form of a plurality of individual bearing members arranged on a pitch circle centered on the axes of the second of the third rings and disposed outwardly of the latter.

Conveniently, each bearing member has a recess therein in which the third ring engages so as to retain the third ring against unwanted axial movement.

Conveniently also, each bearing member is mounted on a respective one of the mounting bolts or the like. It is preferred for each bearing member to be internally screw threaded for screw engagement with the respective mounting bolt whereby the use of separate nuts or the like can be avoided.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an underside plan view of one embodiment of valve according to the present invention shown in a closed condition, and Figure 2 is perspective view of the valve of Fig.

1 shown in an open condition.

Referring now to the drawings, the valve is for controlling the flow of particulate material from a storage container such as a hopper. The valve comprises a flexible sleeve 10 which is formed of coated or uncoated fabric or rubber, and first and second rings 11 and 12, respectively, to which opposite ends of the sleeve 10 are secured. The rings 11 and 12 extend circumferentially with respect to the sleeve 1 0. A plurality of U-shaped mountings 1 3 (in this embodiment 8 are provided) are arranged radially outwardly of the first ring 11.

The free ends of each U-shaped mounting 13 are welded to the first ring 11, suitable slits being provided in the flexible sleeve 10 to accommodate such mountings 1 3. As will be appreciated from Fig. 2, the U-shaped mountings 13 lie in the plane of the first ring 11.

Extending radially outwardly of the second ring 12 are a plurality of connecting bars 14 which are welded at their inner ends to the second ring 12 and at their outer ends to a third ring 1 5 which is arranged in the same plane as the bars 14 and ring 1 2 and is disposed axially with the first and second rings 1 2. Also welded to the second ring 12 is a handle 16. The rings 11, 1 2 and 15, the mountings 1 3 and the connecting bars 14 are ali formed of heavy gauge wire. Thus, it will be appreciated that the assembly of first ring 11 and mounting 1 3 can be readily fabricated in virtually any desired size out of an inherently low-cost material.The same applies to the assembly of second ring 12, connecting bars 1 4 and third ring 15. The handle 1 6 is also formed of a suitably configurated heavy gauge wire 1 7 and a simple push-on plastics sleeve 1 8. The third ring 1 5 is engaged in annular recesses 18 formed in nylon bearing bushes 19. The nylon bearing bushes 1 9 are disposed externally of the third ring 1 5 and are arranged on a pitch circle centred on the axis of the rings 11, 12 and 1 5. Each nylon bearing bush 19 is internally screw threaded for engagement with a respective mounting bolt 20 which passes through a respective one of the U-shaped mountings 13.

In use, the above described valve is mounted on an apertured flange (not shown) surrounding the lower outlet opening of the container. The bolts 20 are engaged with the apertured flange, pass through the respective U-shaped mountings 1 3 and engage with the bushes 1 9. Tightening of the bolts 20 causes the bushes 1 9 to be drawn against the mountings 13 so as to clamp the latter against the underside of the flange. At the same time, this secures the bearing bushes 1 9 relative to the mountings 13 and flange.

At the same time, the third ring 15 5 is held in the desired axial position because of its engagement in the annular recesses 18 of the bushes 19. The construction is such that rotation of the third ring 1 5 about its axis is permitted when the handle is turned. In Fig. 1, the handle 1 6 is shown in a position in which the valve is closed, i.e. a position in which the sleeve 10 is twisted. The handle 1 6 is detachably retained in this position by means of a spring clip 21 formed of a generally U-shaped metal strip which is secured under the head of one of the bolts 20. The spring clip 21 has a lead-in portion 22 which facilitates engagement of the handle 1 6 in the clip 21 but which retains the handle in position.The lead-in portion 22 is inclined so that its inner end lies just in the path of movement of the wire 1 7 over a portion thereof which is engaged with the clip 21. In order to open the valve, the handle 16 is moved in a clockwise direction as viewed in Fig. 1 through 180 degrees until it abuts against a stop 23 secured to that bolt 20 which is diametrically opposite the bolt 20 to which the clip 21 is secured. In this position of the handle 1 6, the second ring 12 has been rotated relative to the first ring 11 so that the sleeve 10 is no longer twisted and, under the weight of material is the container, adopts the configuration shown in Fig. 2 where flow of the material through the valve is permitted.In the above described construction, wire of circular cross section was employed in the fabrication of the rings 11, 12 and 1 5, the mountings 13 and the connecting bars 14.

However, it is to be appreciated that other cross sectional shapes could be used, including tubular sections for large diameter valves and, instead of using metal, plastics material can be used if desired or if necessary.

The fabrication process is inexpensive and permits the fabricated parts of the valve to be manufactured to a high degree of accuracy.

In a modification, intermediate stops may be provided for enabling the valve to be locked in any position between fully open and fully closed.

If desired, and elastomeric sealing ring of Ushaped cross section may be fitted onto the inner diameter of the first ring 11 so that a portion of the ring is disposed between the first ring and the flange to define a flexible gasket between the sleeve 10 and the mounting flange. It is envisaged that such a sealing ring could be used actually to -retain the sleeve 10 on the first ring 11. A similar ring could also be employed to secure the sleeve 10 to the second ring 1 2. However, any desired means may be employed for securing the sleeve 10 to the rings 11 and 12, for example by stitching the sleeve 10, or by welding if the sleeve 10 is formed of a material which can be welded either to itself or to the rings. In the case where the container is itself provided with an internal flexible liner bag, it is envisaged that a sleeve of the liner bag could extend through the valve so as to form a liner protecting the sleeve of the valve.

If desired, the valve described above may be supplied on a disposable hardboard, ply or like annular mounting plate so as to indicate to the customer the method in which the valve is to be mounted on the flange of the container.

In a modification, the valve can be part of the container itself or can have its own backing plate and/or adaptor flange to facilitate mounting on the container.

Claims (9)

1. A valve comprising a flexible sleeve having first and second axially spaced sleeve portions, first and second rings to which the first and second sleeve portions are respectively secured, mounting means secured to and extending outwardly from the first ring to enable the latter to be mounted via bolts or the like on a flange or the like around an opening through which the flow of material is to be controlled in use by the valve, a third ring which is spaced outwardly of the second ring and connected thereto by arms joining the second and third rings and a plurality of individual bearing members arranged on a pitch circle centered on the axes of the second and the third rings and disposed outwardly of the latter, said bearing members being engaged by the third ring and being fixed relative to the first ring and/or to the flange or the like in use, and said third ring being movable relative to the bearing members so as to enable relative rotation between the first and second rings for valve opening and closing purposes.

2. A valve as claimed in claim 1; wherein the first, second and third rings and the arms are fabricated from wire or tube.

3. A valve as claimed in claim 1, wherein each bearing member is an annular bush.

4. A valve as claimed in claim 1,2 or 3 wherein each bearing member has a recess therein in which the third ring engages so as to retain the third ring against unwanted axial movement.

5. A valve as claimed in any preceding claim, wherein each bearing member is mounted on a respective one of the mounting bolts or the like.

6. A valve as claimed in claim 7, wherein each bearing member is internally screw threaded for screw engagement with the respective mounting bolt.

7. A valve as claimed in any preceding claims, wherein the mounting means secured to the first ring comprises a plurality of generally U-shaped mountings, whole arms are secured to the first ring.

8. A valve as claimed in claim 7, wherein the Ushapc I mountings are formed of wire or tube.

9. A valve as claimed in any preceding claim, which is manually operable and has a handle including a configurated wire secured to the second ring.

1 0. A valve substantially as hereinbefore described with reference to the accompanying drawings.