GB2283301A

GB2283301A - Valve operator means, eg handwheel, with position indicator

Info

Publication number: GB2283301A
Application number: GB9321977A
Authority: GB
Inventors: John Hardie Carruthers
Original assignee: Crane Ltd
Current assignee: Crane Ltd
Priority date: 1993-10-26
Filing date: 1993-10-26
Publication date: 1995-05-03
Also published as: GB9321977D0

Abstract

The operator means comprises a moveable part (12), which is fixedly connected to a valve stem (34) when in use, a fixed part (14), which is fixedly connected to a valve body when in use, and indicator means (54) which indicate the degree of opening of the valve. At least one part (54) of the indicator means is provided on the fixed part (14), and engagement means (40), are provided on the moveable part (12) so that upon movement therefore, the engagement means (40) engage the said at least one part (54) of the indicator means. This changes the indication of the degree of opening of the valve as displayed by the said at least one part (54) of the indicator means. <IMAGE>

Description

Operator means for a valve The present invention relates to operator means for a valve.

The need for valve operating handwheels incorporating some form of valve position indicator is well established, especially but not exclusively in heating, ventilating, and air conditioning applications. The purpose of such handwheels is to provide a means of showing the valve user the degree of valve opening with respect to the fully closed or fully open reference conditions. Such devices take many forms but generally they do not give a very accurate reading, or else the indication they do give may be somewhat difficult to read. One previous such handwheel is described in SE-B-448 651. This has the disadvantage that the indication it provides may be upside down relative to the position from which the handle may be readily viewed, and also that the position at which the degree of opening of the valve appears, changes.

Alternatively a previously proposed valve for central heating apparatus has a scale on a moveable part, which is covered by a fixed surround. The latter has a notch revealing a small area of the scale on the moveable part, which provides a reading which is somewhat imprecise.

An aim of the present invention is to overcome one or both of these disadvantages.

Accordingly the present invention is directed to operator means for a valve, the operator means comprising a movable part, which is fixedly connected to a valve stem when in use, a fixed part, which is fixedly connected to a valve body when in use, and indicator means which indicate the degree of opening of the valve, in which at least one part of the indicator means is provided on the fixed part, and engagement means are provided on the movable part so that upon movement thereof, the engagement means engage the said at least one part of the indicator means, to change the indication of the degree of opening of the valve as displayed by the said at least one part of the indicator means.

This may have the advantage of ensuring that the degree of opening of the valve is always indicated at one place that does not move relative to the fixed part.

Preferably, the movable part is rotatable relative to the fixed part, so that the indicator means are in the form of a handwheel.

Preferably the said at least one part of the indicator means comprises a wheel which is rotated by the engagement means of the movable part.

Advantageously the engagement means comprises a tooth on the movable part, which may index such a wheel.

In a preferred embodiment the axis of the rotatably movable part is perpendicular to the axis of the valve. This has the advantage that the operator means has the ability to indicate multiple turns to the user viewing it from the side. To effect this, the wheel may be provided with teeth arranged around the axis of rotation of the wheel, constructed and positioned so that the tooth on the said rotatable part engages one tooth of the wheel each time the rotatable part completes a 3600 turn, with successive teeth of the wheel being engaged by the tooth on the rotatable part upon successive rotations of the rotatable part.

Preferably the rotatable part is equipped with a scale. This has the advantage of allowing fractions of a turn of the rotatable part to be measured as well.

The operator means preferably comprises a plastics material.

An example of a handwheel made in accordance with the present invention is shown in the accompanying drawings in which Figure 1 is a side view of such a handwheel; Figure 2 is a top view of the handwheel shown in Figure 1; Figure 3 is an exploded side, sectional view of the handwheel shown in Figure 1; and Figure 4 is an underneath view of the lower part of the handwheel shown in Figure 3.

Figure 1 shows a handwheel 10. The handwheel 10 comprises two plastics parts, an upper part 12 and a lower part 14. Both parts 12 and 14 have a generally circular cross-section. The upper part 12 has a generally mushroom shape whereas the lower part 14 is generally tubular in form. The upper part 12 is so moulded that it has three lugs 16 round its upper periphery spaced apart at approximately 1200 intervals to facilitate a good hand grip. The upper part 12 has a scale 18 from 0 to 9 printed round its lower periphery adjacent to a bottom edge 17.

The upper part 12 of the handwheel 10 is fitted flush with the lower part 14 round its bottom edge 17. A bottom region of the lower part 14 has a smaller diameter than its upper region, with an hexagonal internal crosssection (not shown in Figure 1), which is slightly larger than a fixed hexagonal valve component onto which the lower part 14 of the handwheel 10 is engaged. A flat or curved front plate 20 is situated parallel to the turning axis of the handwheel 10 on the lower part 14 at the intended front of the handwheel 10. This plate 20 is formed with a window 22 through which a digit indicating the degree of opening of the valve, in terms of complete handwheel turns on a scale from 0 to 4, can be seen. Above the window 22 there is a mark 24 adjacent to the top outside edge of the lower part 14, which is used to read off the scale 18 on the upper part 12.The scale 18 thus indicates partial handwheel turns which have been effected. A lug 26 extends downwardly from the bottom edge of the lower part 14, and is formed with a hole by means of which a valve reference tag or disc may be attached.

Figure 2 shows clearly the positions of the three lugs 16 relative to each other.

Figure 3 shows that the upper part 12 has a hollow interior with a hollow central hub 30 extending downwardly from its top. The hollow hub 30 extends below the outside edge 17 of the upper part 12. The bottom of the hollow hub has internal splines 32 which engage external splines round a stem 34 of a valve 35 to enable the upper part 12 to rotate the valve stem 34.

The top of the upper part 12 is sealed with a cap 36. This can be held in position by a piece of wire which can be inserted through recesses 37 (shown in Figure 2) formed in the top of the upper part 12, underneath bridge portions which extend across those recesses, and through a bore (not shown) in the cap 36 thus preventing unauthorised access to a handwheel retaining device (not shown) contained within the hollow hub portion 30. The inside of the upper part 12, adjacent to the outside bottom edge 17 is formed with retaining protuberances 38.

The upper part 12 is also formed with radially extending webs 39 between the hub 30 and its main body. A lower part of one of those webs 39 defines an indexing tooth 40 which extends below the bottom edge 17.

The lower part 14 has a cylindrical extension 42 the diameter of which is such that it fits inside the bottom edge 17 of the upper part 12. This extension is undercut to form a circumferential retaining lip 44. When the upper and lower parts 12 and 14 are brought together, the protuberances 38 snap underneath the retaining lip 44 so as to retain the upper part 12 on the lower part 14 whilst at the same time allowing those two parts to be rotated relative to one another. The lower part 14 has a strengthening diaphragm 45 extending across it at a position generally mid-way between its upper and lower rims. A hole 46 is formed in the centre of the diaphragm 45 to allow the valve spindle 34 to extend through it. The diameter of the hole 46 is sufficient to enable the lower end of the hollow central hub 30 to pass through in a close fit to ensure that the upper part 12 rotates smoothly.

A bottom part of the lower part 14 is in the form of a skirt 48 which on its inside engages a fixed hexagonal or other shaped component 50 of the valve 28. The lower part 14 has a cut away region on its intended front side In the centre of this region, a spigot 52 extends radially outwardly from the skirt 48. A hollow shaft 51 of a wheel 54 is mounted on this spigot 52. The wheel 54 has a flat front circular face 56 bearing numerals. The shaft 51 has bevelled gear teeth 60 round its outside surface. One of the gear teeth 60 projects upwardly through a hole in the diaphragm 45 into the upper interior of the lower part 14.

The cut away region and the wheel 54 are covered by the plate 20 so that the window 22 reveals one of the numbers on the face 56 of the wheel 54 indicative of the degree of opening of the valve in terms of complete turns of the upper part 12.

Figure 4 clearly shows a flat formed in the cut away region and the position of the wheel 54 at the side of the lower part 14 such that it rotates about an axis which is generally perpendicular to the axis of the valve. The engagement of the hexagonal component 50 with the skirt 48 of the lower part 14 can also be seen.

In the illustrated form of the handwheel 10, the upper part 12 is coupled to the lower part 14 in such a manner that relative rotary motion can take place whilst the parts are inhibited from relative axial movement. In the assembled condition the indexing tooth 40 has freedom to rotate within the housing defined above the diaphragm 45. The indexing tooth 40 engages one of the bevel gear teeth 60 on the wheel 54 with each rotation of the upper part 12 of the handwheel 10 thus indexing the wheel 54 through a predetermined angle, being the angular spacing between successive numbers on the face 56, with each rotation.

The window 22 in the plate 20 reveals only one of the numbers on the face 56, being that number which is indicative of the relative opening of the valve in terms of complete turns of the upper part 12. The mark 24 is adjacent to the 0 to 9 scale 18, at a position thereof which is indicative of a fraction of a turn of the upper part 12. Thus the degree of opening of the valve in terms of whole turns and fractions of a turn of the upper part 12 can be observed at a glance.

Numerous variations and modifications to this illustration will readily occur to a reader of ordinary skill in the art without taking it outside the scope of the present invention. For example, the scales could extend around the upper part 12, outwardly thereof, so as to face in the same, intended upward, direction of the top of the upper part 12. Whilst the scale on the face 56 comprises the numbers 0 to 4, the range may be smaller or larger, for example the scale may comprise the numbers 0 to 9. Whilst the engagement between the handwheel 12 and the valve stem 34 in the illustrated construction is by way of splines, other forms of engagement would be possible, for example interengaging flats.

Whilst Figure 1 shows the number on the face 56 and the scale 18 in an upright position when viewed in elevation and the valve axis vertical, depending upon the orientation of the valve to which the handwheel is attached, the numbers on the face 56 and also the numbers on the scale 18 may alternatively be so oriented that when the plate 20 is viewed with the valve to the left in the field of view and the upper part 12 to the right, the mark 24 appears as a decimal point with the whole number on the face 56 appearing upright and correctly placed to the left of the decimal point, and the tenths of a turn number on the scale 18 appearing upright and correctly placed to the right of the decimal point.

Claims

1. Operator means for a valve, the operator means comprising a moveable part, which is fixedly connected to a valve stem when in use, a fixed part, which is fixedly connected to a valve body when in use, and indicator means which indicate the degree of opening of the valve, in which at least one part of the indicator means is provided on the fixed part, and engagement means are provided on the moveable part so that upon movement thereof, the engagement means engage the said at least one part of the indicator means, to change the indication of the degree of opening of the valve as displayed by the said at least one part of the indicator means.

2. Operator means according to claim 1, in which the moveable part is rotatable relative to the fixed part, so that the operator means are in the form of a handwheel.

3. Operator means according to claim 1 or claim 2, in which the said at least one part of the indicator means comprises a wheel which is rotated by the engagement means of the moveable part.

4. Operator means according to claim 3, in which the axis of rotation of the wheel is perpendicular to the axis of the valve.

5. Operator means according to any preceding claim, in which the engagement means comprises a tooth on the moveable part.

6. Operator means according to claim 5 read as appended to claim 3 or 4, in which the said tooth indexes the wheel.

7. Operator means according to claim 6, or to claim 5 read as appended to claim 3 or 4, in which the wheel is provided with teeth arranged around the axis of rotation of the wheel, constructed and positioned so that the tooth on the said moveable part engages one tooth of the wheel each time the moveable part completes a 3600 turn, with successive teeth of the wheel being engaged by the tooth on the moveable part upon successive rotations of the moveable part.

8. Operator means according to any preceding claim, in which the moveable part is equipped with a scale.

9. Operator means according to any preceding claim, comprising a plastics material.

10. Operator means according to claim 1 and substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.