GB2205928A - A valve - Google Patents

Abstract

In a valve which comprises two valve plates (18, 19) having mutually parallel and mutually adjacent rotation shafts which present journal studs (22) mounted in hinge plates (32, 34), at least one of the valve plates (18, 19) is provided with valve setting means in the form of a setting shaft (24) which projects outwardly from at least one of the journal studs (22) and which is provided with a tool-accommodating groove (26), or a setting means, e.g. a cord or the like (50, 52) which acts directly on the valve (18, 19). Each of the valve plates is provided with a journal pin (28) for one end of pivotal arms (30, 31), the other ends of which are movably connected together by means of a bolt (44), which is guided for positive movement in a symmetrically located guide slot in the adjacent hinge plate (32). The pivotal arms (30, 31) transfer position changes caused by the setting means for effecting simultaneous movement of the valve plates. <IMAGE>

Description

A VALVE The present invention relates to a valve.

Valves of this kind are intended primarily for use in ventilation systems, and particularly for guiding the incoming gas to an inlet box of an air diffuser. The valve is usually placed in the inlet sleeve of the inlet box. Simple valve plates which cover the whole of the inlet passage when closed are less suitable for this purpose. It is normally necessary to place such valve plates at some distance from the mouth of the sleeve, normally a distance which corresponds to twice the diameter of the sleeve, therewith increasing the requisite length of the sleeve and thus also the total amount of space required. Consequently, valves of aforesaid kind used for this purpose are often provided with two valve plates which have mutually parallel axes of rotation, and which are provided with setting means for symmetrically changing the positional setting of the valve plates.

One such known valve includes two semi-circular plates or dishes which when closed shut-off a ventilation duct or channel of circular cross-section. Adjacent to the straight sides of respective valve plates, at the peripheral edges thereof, are located right-angled attachment lugs which are provided with holes for journalling the plates. The plates are secured by rivets in fittings provided around the connecting end of a tubular sleeve. Arranged centrally on respective valve plates is an outwardly projecting toothed ring. Located in the centre of respective toothed rings, coaxial with the journalling holes in the attachment lugs, are mounting holes for a valve plate setting means. This setting, or adjusting, means includes a worm drive which engages the toothed rings on respective valve plates.The worm drive is connected to an operating shaft for effecting changes in the positional settings of the valve plates, this shaft extending through the ventilation duct or the sleeve in the direction of their respective longitudinal axes.

This known valve has the disadvantage that the position of the operating shaft, this position being contingent on the construction of the valve, means that complicated movement transmission devices must be connected to the operating shaft of the valveplate setting means when the connecting sleeve is connected laterally to the inlet box. Furthermore, the known valve opens towards the incoming flow, there being thus formed a wide central slot. When the valve is only partially open, the flow concentrates at this slot, or gap, which results in uneven air distribution in the inlet box and necessitates the provision of separate flow-equalizing guide vanes. In addition, the noise generated by this known valve is very troublesome when the valve is only partially open.The valve also has a relatively expensive and mechanically complicated construction and must be manufactured with high precision, so as to eliminate the risk of malfunction in operation.

Another, similar construction includes a centrally located, axially stationary, but rotatable, rod or shaft. The shaft is screw-threaded and carries a screw-threaded element which is connected to the valve plates by means of slewing arms or brackets. The valve plates are also provided with rightangled, outwardly projecting journal plates provided with journal holes, the attachment points of the arms being located outwardly of the rotational axis of the valve plates.

This valve arrangement is encumbered with essentially the same drawbacks as the aforedescribed, namely complicated operating means in the case of laterally connected inlet sleeves and troublesome noise levels when the valve is only partially open. The valve is also of relatively expensive construction and requires the provision of a separate brace or strut with a bearing for stationary attachment of the screw-threaded shaft.

CH-A-598 549 describes and illustrates a butterfly valve comprising pivotal arms which are connected rigidly to the rotation shafts or spindles of the valve plates, the free end of each of the arms being guided along a guide slot or track which extends transversally to the passageway or duct in which the flow of medium is to be controlled. The external mechanism can be located in a different region of the system.

Consequently, it is probable that part of the sleeve forming this passageway must always be caused to project outwards from part of the building incorporating the system, e.g. a ceiling, which is highly disadvantageous. Furthermore, powerful lever forces are required to pivot or slew the valve plates with the aid of the torque which acts directly on the rotation shafts of the plates. It is also likely that the rigidly connected pivot arms will break lose from the shafts and thus render the valve unusable. Furthermore, the guide points, which are separated from one another locally, require a relatively long guide track, the displacement path of which is not proportional in relation to the swinging movements of the valve plates.Finally, the stopping action which is necessary in a given setting position requires the provision of a stable, external locking device of the illustrated kind, which complicates the valve and renders it more expensive.

SE-C-183 592 illustrates a valve setting arrangement which lacks the presence of pivot arms or slewing arms. Consequently, the valve plates are not guided satisfactorily and are not stopped in desired positions.

Consequently, the object of the present invention is to provide a valve of the aforesaid kind which is of simple and operationally reliable construction; which can be manufactured with less precision than prior art valves of this kind and still be equally as effective; which can be fitted readily to both laterally located and axially located connecting sleeves; which provides good flow distribution on the outlet side; which requires only a short installation length; which has low manufacturing and maintenance costs; which has a low noise level; and which constitutes a general step forward in this art.

According to the invention there is provided a valve, comprising two valve plates having substantially mutually parallel and adjacent rotation shafts and provided with plate setting means for effecting proportional, symmetrical and simultaneous changes to the positional setting of the plates via a linkage system which includes two arms one end of which is connected to a respective valve plate and the other end of which is guided by co-operable guide means, the arms having the form of pivot arms whose one ends are pivotally journalled on journals which project outwardly from respective valve plates and which extend substantially parallel with the rotation shafts, and whose other ends are pivotally journalled on a common projection which is movable along a guide positioned substantially perpendicularly in relation to the valve plates when said plates are located in a mutually common plane (closing plane).

In accordance with one particularly advantageous embodiment of the invention, the rotation shafts of respective valve plates may lie substantially in the plane of the blades.

This configuration results in only a comparatively narrow centre gap and in only a low noise level when the valve is partially open.

The invention will now be described in more detail with reference to a preferred non-limiting embodiment thereof and with reference to the accompanying drawings, in which Figure 1 is a plan view of an inventive valve installed in a distribution box; Figure 2 is an end view of the valve illustrated in Figure 1; Figure 3 is a side view of the valve illustrated in Figure 1; Figures 4 and 5 illustrate different views of alternative embodiments of hinge plates or hinge fittings intended for an inventive valve; and Figures 6 and 7 illustrate different examples of inlet boxes provided with valves according to the invention.

Figures 1-3 illustrate a box 10, for instance an infeed box, forming part of a ventilation system and including an inlet sleeve 12 which is connected with a flange 14 in the box 10.

Located in front of the mouth of the sleeve is a valve constructed in accordance with the invention, said valve being generally referenced 16. The valve 16 comprises two substantially semi-circular valve plates 18, 19. Extending along the straight sides of the valve blades are respective semicircular grooves or hollows 20, which continue into rotation shafts 22 projecting outwardly on both sides of the valve plates. The grooves 20 are effective in stiffening respective valve plates. The extension of the grooves into respective shafts 22 impart to the shafts a semi-circular shape which enables the shafts to be readily journalled and rotated.

Arranged on one valve plate 18, on the one rotation shaft thereof, is a valve-blade plate setting or adjusting shaft 24 which is provided with a groove 26 for accommodating a screwdriver or some other suitable tool. The setting shaft connects with the bottom of the groove 20 in the valve plate 18 and is secured, for instance, by means of spot welding. Arranged on one side of the valve plates 18, 19 are journal pins 28 for pivot or slewing arms 30, 31, said journal pins being pressed to a semi-circular shape. Pressing of the semi-circular journal pins continues into the actual valve plate itself.

The rotation shafts 22 are mounted in holes 36 provided in angled hinge plates 32, 34. The angled part of respective hinge plates is provided with holes 38 or receiving/fastening screws or the like. The hinge plates, however, can also be secured by spot welding or in some other way. One hinge plate 32 has an extension 40 in which there is provided a longitudinally extending slot or track 42. Extending through the slot 42 is a bolt 44 which secures together the free ends of the pivotal arms 30, 31, the other ends of which are journalled on the journal pins 28 of respective valve plates.

The extension 40 also has formed therin a recess of cut-out 48, which forms a stop abutment for at least one of the journal pins 28.

Figure 1 also illustrates alternative means for adjusting the setting of the valve plates, said means having the form of wires or cords 50, 52 which are attached in holes 54 in one valve plate 18. The one wire or cord 50 passes through a bushing 56 located closely adjacent the mouth of the sleeve 12 in an angle bracket 58. The other wire or cord 52 passes through a guide means located in front of the valve plate 18, to the left thereof as seen in Figure 1. In Figure 1 this guide means is illustrated schematically in the form of ring 60. The guide means may, also have the form of a throughpassing opening located in a wall of the inlet box 10.

Subsequent to passing through the bushing 56 and the ring 60, the wires or cords 50, 52 can be drawn out from-the inlet box in any desired manner, so as to be readily accessible for changing the setting of the valve. The valve can be closed by pulling on one wire or cord 50 and opened by pulling the other wire or cord 52.

The valve operates in the following manner. A change in the setting of the valve plate 18 by pulling one of the wires 50, 52, or by rotating the setting shaft 24 with the aid of a suitable tool causes the associated pivot arm 30 to move.

The end of the pivot arm remote from the valve plate 18 will therewith be guided positively by the bolt 44 and move along the elongated slot 42. The end of the other pivot arm 31 remote from the valve 19 will be caused to accompany this movement and therewith change the setting of the valve plate proportionally to the setting of the valve plate 18. In the case of the illustrated, preferred embodiment the elongated slot 42 is symmetrically situated and the pivot arms 30, 31 are of mutually equal size. Consequently, the valve plates 18 and 19 will move symmetrically to mutually the same extent.

The pivot arms 30 and 31 may also be given mutually different lengths and/or the slot 42 may be positioned symmetrically, if it is desired to provide for non-uniform flow distribution on the downstream side of the valve.

An advantage is gained when an elastic element 62, for instance, a rubber bush or a number of resilient cup washers is, or are, placed on the bolt 44. The elastic element is effective in urging the pivotal arms against the hinge bracket and acts as a brake to hold the valve plate firmly in its set position.

The recess of cut-out 48 functions as a stop abutment for the journal pins 28 and delimits the opening movements of respective valve plates to a preferably fully open terminal position 18', 19'. The purpose of the stop abutment 48 is to prevent the pivotal arms and the valve plates from adopting or passing a dead-point position, in which pivot arms and valve plates lie in a straight line with one another. It is namely not possible to return the valve plate 19, which lacks position setting means, from such a dead-point position.

When the valve plates 18, 19 of the embodiment illustrated in Figures 1-3 are closed, the plates take a position slightly in front of the mouth of the sleeve 12, e.g. at a distance of 5mm therefrom. This results in an advantageously low noise level of the valve in its closed position.

Figures 4a, b and 5a, b illustrate an alternative embodiment of hinge brackets 32', 34'. These hinge brackets are bent to form a double angle at their attachment end, so that the brackets can be secured to the inner surface of a sleeve or ventilation duct, by means of holes 3-8. The actual attachment part 64 may be sent so as to lie evenly against a round sleeve wall. Such hinge plates or brackets 32'. 34' can be fitted at any selected location on a ventilation duct or sleeve and the positioning of such brackets is not restricted to a location in front of the mouth of a sleeve. In the case of this alternative embodiment, the means for stopping movement of the valve plates are formed by the sides of an inwardly folded flange 66, which is preferably located on the hinge bracket 34' located opposite the pivot arms.

Figures 6 and 7 illustrate different exemplifying applications of the inventive valve. Figure 6 is a sectional view of an elongated inlet box 10 provided with an elongated outlet aperture which faces one or more diffusers, not shown in detail. Two ventilation conduits 72 are connected to the inlet box 10. Located in front of the mouths of the ventilation conduits or ducts is a respective inventive valve 16.

In this case, it is possible to adjust each valve separately to a different setting, in order to obtain mutually different flows in different parts of the inlet box 10. Figure 6 also shows operating wires or cords 50, 52 which extend out through openings 74 to the outside of the air diffuser.

Figure 7 illustrates an inlet box 10 of a ceiling airdiffuser 76 mounted on a ceiling 78. In this case, the extension 40 of the valve 16 continues through the ceiling 78 and into the air diffuser 76. The setting of the valve is changed with the aid of a screwdriver or some other suitable tool which is inserted through the outlet grid of the diffuser or through a separate opening. The extension 40 may advantageously be connected to a separate connecting piece. This enables the inventive valve to be adapted readily to various applications and to different requisite lengths of the setting shaft 40.

The illustrated embodiment includes movement transmission means in the form of two pivotal arms 30, 31 which are guided in a slot 42. It will be understood, however, that other movement transmissiom means may be used, such as a scissor- like arrangement with mutually intersecting, pivotally connected arms, the free ends of which are connected to further mutually pivotally connected arms. The movement transmission means may also comprise two toothed rings arranged to co-act one with the other. The embodiment illustrated in the Figures is preferred, however, since it is more stable and enables the valve to be held securely in a set position by means of the brake element 62.

In the case of the illustrated example, the setting shaft 40 and the setting wires or cords 50, 52 are arranged on one and the same valve plates. They may, however, be arranged on different valve plates. Alternatively, each of the setting wires or cords 50, 52 may be arranged on a respective valve plate. This will avoid pronounced changes in the direction of the wires 50, 52.

Setting shafts may also be provided on more than one of the four rotation shafts 22. By providing, for instance, two setting shafts, one can be held as a reserve for the event of the other shaft being damaged. Furthermore, the setting shaft may be remotely controlled with the aid, e.g., of a servomotor, while the other is manipulated directly in position with the aid of a suitable tool.

Instead of wires 50, 52 other forms of known setting means may be used, such as chains or push-and-pull rods for example, for the purpose of changing the positional setting of one of the valve plates 18, 19.

The invention is not restricted to the illustrate embodiments, since the different components thereof can be varied and modified in any desired manner within the scope of the present invention as defined in the following claims.

The valve plates need not necessarily be semi-circular in shape, but may have any desired shape. so as to conform with an associated ventilation duct. Furthermore, the valve plates may be journalled in any suitable manner for rotation around a pivot axis. For example, the plates may be provided with a through-passing shaft which is attached to one side of the valve plate, or angularly bent attachments with holes for receiving journal pins in accordance with the aforedescribed known construction. This results, however, in impaired properties with regard to flow distribution and noise, in comparison with the aforedescribed inventive embodiment.

The inventive valve will provide a highly favourable flow distribution when the valve is located in an inlet box in front of the mouth of a sleeve. The flow is deflected symmetrically towards both sides, while only a minor part of the flow will pass through the centre gap defined between the valve plates. This provides good flow distribution, particularly in the case of long inlet boxes, without requiring the provision of guide vanes and at low noise levels.

The nut-provided bolt 44 can be replaced with some other type of joining element which passes through the elongated slot 42 and the holes in the pivot arms 30, 31 remote from the valve blades. Such joining elements may, for instance, have the form of a rivet and catch washer, a pop rivet or some other rivet or a cotter pin.

As will be understood, the setting shaft 24 may be provided with any desired setting means and is not restricted to a chisel slot 26. The setting shaft 24 may also be provided with engagement surfaces for accomodating other tools, or may be connected to a rigid or flexible extension shaft provided with a knob or some other form of handle. The setting shaft may also be provided with a radially and outwardly projecting setting arm capable of being manipulated in a desired manner. This arm may, for instance, be connected to cords or the like corresponding to the cords or wires would be located outside the box 10 and the duct 72 respectively. This is particularly benificial when the valve is arranged in a duct system for conveying or contaminated gases, such as flue gases for example.

Claims (11)

1. A valve, comprising two valve plates having substantially mutually parallel and adjacent rotation shafts and provided with plate setting means for effecting proportional, symmetrical and simultaneous changes to the positional setting of the plates via a linkage system which includes two arms one end of which is connected to a respective valve plate and the other end of which is guided by co-operable guide means, the arms having the form of pivot arms whose one ends are pivotally journalled on journals which project outwardly from respective valve plates and which extend substantially parallel with the rotation shafts, and whose other ends are pivotally journalled on a common projection which is movable along a guide positioned substantially perpendicularly in relation to the valve plates when said plates are located in a mutually common plane (closing plane).

2. A valve according to Claim 1, the projection comprising a bolt and the guide a slot.

3. A valve according to Claim 1 or Claim 2,in which arranged in the common journalling region of the pivot arms is a friction brake which is provided with elastic means for regulating the braking and holding force respectively.

4. A valve according to any one of the preceding claims, in which the valve plates have outwardly projecting parts which form the rotation shafts and/or the journals, the said plate parts being preferably pressed to a semi-circular shape corresponding to associated journal holes.

5. A valve according to any of Claims 1-4, in which the rotation shafts and/or the journals are located substantially in the plane of the valve plates.

6. A valve according to Claim 5, the journals comprising journal pins.

7. A valve according to any one of Claims 1-6, in which there are hinge plates which present stop abutments for limiting the opening movement of the valve plates.

8. A valve according to any one of Claims 1-7, in which said valve plate setting means includes a cord or like element which is adapted to move one of the valve plates in its valve closing direction, while another cord or like element is adapted to move one of the valve plates in its valve opening direction.

9. A valve according to any one of Claims 1-8, in which the valve plate setting means comprises an extended part of one of the shafts which extended shaft part is provided with a valve plate setting element.

10. A valve according to Claim 9, the valve setting element comprising a groove in the free end-surface of said extended shaft part.

11. A valve, substantially as hereinbefore described with reference to the accompanying drawings.