GB2091885A

GB2091885A - Gas meters

Info

Publication number: GB2091885A
Application number: GB8101905A
Authority: GB
Original assignee: United Gas Industries Ltd
Current assignee: United Gas Industries Ltd
Priority date: 1981-01-22
Filing date: 1981-01-22
Publication date: 1982-08-04
Also published as: GB2091885B

Abstract

A domestic gas meter 11 includes means 13 for indicating if the meter is not mounted vertically. When not vertical inaccuracies may occur. An indicator 13 comprises a ball 16 lying in a depression 15 and which escapes from the depression when more than a predetermined tilt angle is experienced. An alternative indicator comprises a tube containing normally separate chemical materials which become mixed by tilting and change colour. The meter may also have a butterfly valve in the inlet or outlet tubes which is gravity-sensitive and closes off or restricts the supply of gas when the meter is tilted. Gas flow may be reduced by a pendulous length of flexible tube with a neck portion at to upper end and weighted at to free lower end. When the meter tilts the tube remains vertical pivoting about the neck. <IMAGE>

Description

SPECIFICATION Gas meters This invention relates to gas meters of the kind in which back-and-forth movements of diaphragms are counted to measure the flow of gas causing said back-and-fourth movements. Such meters may be inaccurate if not mounted substantially vertically.

The invention according to one aspect provides a device for securing to or integral with the meter which indicates when the meter is not vertical or has been out of vertical. According to one embodiment such a device comprises a ball lying in a depression such that the ball rolls out of the depression when the meter is tilted more than a predetermined amount. The device may include a slot into which the ball rolls when it leaves the depression and guide means for guiding and restraining the movement of the ball.

According to another embodiment such a device comprises a tube containing two normally separated chemical materials which become mixed when the tube is tilted and which react chemically to provide a visible indication, e.g. a colour change.

According to another aspect the invention provides means for restricting or cutting off gas flow through the meter when the meter is not correctly upright. The means may comprise a valve operating in an inlet or outlet tube of the meter, which is moved by a gravity-sensitive means, e.g. a pendulum or similar weight. According to one embodiment the valve is a butterfly valve mounted on a rod carrying a pendulum weight. According to another embodiment the valve operation comprises collapsing a flexible tube. The flexible tube may have an annular weight secured to one free end to provide a pendulum effect, the other end of the tube being fixed in the meter. It may have a waisted area which collapses when bending forces are applied between the free end and fixed ends of the tube when the meter is tilted.

Specific embodiments of the invention are shown in the accompanying drawings, in which: Figure 1 is an exterior view of a gas meter incorporating two alternative indicator devices, Figure 2 is a plan view of the interior of one of the devices of Figure 1, Figure 3 is a side section taken on the line A - A of Figure 2, Figure 4 is a diagrammatic representation of a gas flow restrictor in two positions, and Figure 5 is a side view of another form of gas flow restrictor.

Referring first to Figure 1, a domestic dry gas meter 11 is of the kind in which the back-and-forth movements of diaphragms (not shown) are translated into rotations of counters which indicate the total counted in an index compartment 12. If the meter is not mounted substantially vertically, as shown in the drawing, then counter inaccuracies can occur.

On the upper, normally horizontal surface of the index compartment 12 is mounted an indicator 13 for indicating deviation of the surface from a horizontal position in any sense. As seen best in Figures 2 and 3, the indicator 13 comprises a flat cup-shaped housing 14 of moulded plastics material. The bottom interior face of the housing is shaped to provide a shallow central depression 15 in which is seated a ball 16.

Surrounding the depression 15 are a series of gates 17, each defined by converging walls 18 which converge to a size through which the ball may just pass. The bottom face 19 of each gate drops towards the outer circumference of the housing. Between adjacent gates are circumferential slots 20 at a lower level than the gates.

A closure member 22 for the housing, shown only in Figure 3, comprises a central lens 23 through which the depression 15 can be viewed and opaque areas 24 surrounding the lens. The sides of the closure member engage within the outer walls 25 of the housing and have spring fingers 26 which are resiliently deformed while the closure member is pressed into the housing. When the closure member is fully home the fingers drop into openings 27 in the housing. The closure member cannot then be removed without cutting it open.

In use the meter is assembled and transported with the housing 13 secured to or formed integrally with the housing of the index compartment 12. The closure member and ball are kept separately until the actual fitting of the meter in its position of use.

The ball is then dropped into the central depression and the closure member pressed into its latched condition. If then the meter tilts out of its vertical position the ball will run up over the edge of the depression into one of the gates 17 depending on the direction of tilt. The ball will then pass through the gate and become trapped in one of the slots 20.

Inspection through the lens 23 will show that the meter has been tilted and appropriate remedies applied. The angle through which the meter must be out-of-vertical before the ball will run out of the depression is of course determined by the angle of the sides of the depression 15. The ball 16 is preferably made of a plastics material, and may have a luminous or fluorescent coating. Should the meter be disturbed at any time after fitting, the absence of the ball from the depression will indicate to the meter reader that the meter has been registering inaccurately.

A second form of indicator device, alternative to the above described device but shown for convenience on the same meter of Figure 1, comprises a glass tube 30 secured to the front, normally vertical, face of the index compartment 12, positioned so as not to obscure the index reading. The tube contains two chemical materials which are held separate while the tube is vertical but which mix when the tube departs more than a predetermined angle from the vertical. When mixed, a colour change takes place so indicating the fact that the meter has been out-of-vertical. The chemical material may for instance be a liquid normally at the lower end of the tube and a solid or powder at the upper end of the tube.

When the liquid flows into contact with the solid or powder, the colour change takes place, for instance the liquid may turn red.

Additionally or alternatively to indicating present or past tilt of the meter, the invention also provides means for cutting off or restricting the supply of gas while the meter is not vertical. As shown in Figure 1, the gas enters the meter at 31 and leaves it after metering through an exhaust connection 32. Either the entry or exit of gas may be restricted as described hereinafter, although it is preferred that inlet gas should be so restricted.

Figure 4 shows a butterfly valve 34 secured to a rod mounted in bearings to rotate in a tube 35 extending into the meter from the entry connection 31 so as to lead gas into the meter. A pendulum weight 36 is rigidly fixed to one end of the rod outside the tube 35, the attitude of the weight relative to the butterfly valve being such that when the tube 35 is vertical the valve is open sufficiently to pass full gas flow. When the tube 35 is tilted through an angle A, the valve remains held by the weight in the same position which as shown restricts the flow of gas. The valve is designed so that even when fully closed, there is a small leakage of gas therearound, sufficient to maintain pilot lights, but not sufficient to feed a gas fire; for instance.The effect, therefore, is that the meter will only allow a very restricted supply of gas while it is tilted out of the vertical in one plane, for instance movement in or out of the plane of the paper as shown in Figure 1. Gas will return to full supply when the meter is righted. As indicated, the above embodiment only reacts to movement in one plane, but the embodiment of Figure 5 reacts to all tilting motion. The inlet connection 31 has secured to it a flexible sleeve 40 of rubber or plastics material, extending into the gas meter. The lower end of the sleeve is floating, but has an internal annular ring 41 secured to it, the ring being of metal or plastics material and functioning to provide weight at the lower end of the sleeve. Mid-way in its length the sleeve may be waisted at 43.When the meter is tilted in any direction, the weight 41 tends to remain vertically below the upper end of the sleeve like a pendulum. The sleeve therefore is subjected to a bending force between its ends, which tends to collapse the sleeve at its mid-point, so closing off the access 6f gas. The waist 43 determines the location and aids the collapse of the sleeve. A by-pass opening 44 is provided upstream of the waist to ensu;e sufficient gas supply to maintain pilot lights, even when the sleeve is collapsed. When the meter is righted, the sleeve opens up again and full gas supply is again available.

CLAIMS (Filed 12Jan 1982) 1. A device for securing to or formed integrally with a gas meter adapted to be operated when the meter is tilted out of the vertical by a predetermined angle and to provide an indication that the meter is or has been so tilted and/or to limit the flow of gas through the meter while it is so tilted.

2. A device as claimed in claim 1, comprising a depression in which a ball lies in use, such that the ball will roll out of the depression when the meter is tilted through said predetermined angle.

3. A device as claimed in claim 2, including recess means into which the ball rolls when it leaves the depression and guide means for guiding the ball into said recess means.

4. A device as claimed in claim 3, wherein thereis a plurality of recess means and guide means for each recess means.

5. A device as claimed in any of claims 2 to 4, comprising a housing providing said depression, recess means and guide means and a closure member through which the depression may be viewed but not the recess means.

6. A device as claimed in claim 1, comprising a tube containing two normally-separated chemical materials which become mixed when the tube is tilted through said predetermined angle and react chemically to provide a visible and permanent indication of the tilt.

7. A device as claimed in claim 1, comprising valve means in an inlet or outlet tube of the meter, which is operated by a gravity-sensitive means so as to close off the valve means as the meter is tilted to said predetermined angle.

8. A device as claimed in claim 7, wherein said gravity-sensitive means comprises a pendulum weight rigidly secured to rotate with a closure valve plate of the valve means.

9. A device as claimed in claim 7, wherein the valve means comprises a flexible tube secured to the inlet or outlet tube at one end and having a free end to which is secured an annular weight.

10. A device as claimed in claim 9, wherein the flexible tube has a waisted area which collapses when the meter is tilted to said predetermined angle.

11. A device substantially as described hereinbefore with reference to Figure 1 or Figures 2 and 3, or Figure 4 or Figure 5 of the accompanying drawings.

12. A gas meter having a device as claimed in any of claims 1 to 11.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

Additionally or alternatively to indicating present or past tilt of the meter, the invention also provides means for cutting off or restricting the supply of gas while the meter is not vertical. As shown in Figure 1, the gas enters the meter at 31 and leaves it after metering through an exhaust connection 32. Either the entry or exit of gas may be restricted as described hereinafter, although it is preferred that inlet gas should be so restricted.

Figure 4 shows a butterfly valve 34 secured to a rod mounted in bearings to rotate in a tube 35 extending into the meter from the entry connection

31 so as to lead gas into the meter. A pendulum weight 36 is rigidly fixed to one end of the rod outside the tube 35, the attitude of the weight relative to the butterfly valve being such that when the tube 35 is vertical the valve is open sufficiently to pass full gas flow. When the tube 35 is tilted through an angle A, the valve remains held by the weight in the same position which as shown restricts the flow of gas. The valve is designed so that even when fully closed, there is a small leakage of gas therearound, sufficient to maintain pilot lights, but not sufficient to feed a gas fire; for instance.The effect, therefore, is that the meter will only allow a very restricted supply of gas while it is tilted out of the vertical in one plane, for instance movement in or out of the plane of the paper as shown in Figure 1. Gas will return to full supply when the meter is righted. As indicated, the above embodiment only reacts to movement in one plane, but the embodiment of Figure 5 reacts to all tilting motion. The inlet connection 31 has secured to it a flexible sleeve 40 of rubber or plastics material, extending into the gas meter. The lower end of the sleeve is floating, but has an internal annular ring 41 secured to it, the ring being of metal or plastics material and functioning to provide weight at the lower end of the sleeve. Mid-way in its length the sleeve may be waisted at 43.When the meter is tilted in any direction, the weight 41 tends to remain vertically below the upper end of the sleeve like a pendulum. The sleeve therefore is subjected to a bending force between its ends, which tends to collapse the sleeve at its mid-point, so closing off the access 6f gas. The waist 43 determines the location and aids the collapse of the sleeve. A by-pass opening 44 is provided upstream of the waist to ensu;e sufficient gas supply to maintain pilot lights, even when the sleeve is collapsed. When the meter is righted, the sleeve opens up again and full gas supply is again available.

CLAIMS (Filed 12Jan 1982) 1. A device for securing to or formed integrally with a gas meter adapted to be operated when the meter is tilted out of the vertical by a predetermined angle and to provide an indication that the meter is or has been so tilted and/or to limit the flow of gas through the meter while it is so tilted.
2. A device as claimed in claim 1, comprising a depression in which a ball lies in use, such that the ball will roll out of the depression when the meter is tilted through said predetermined angle.
3. A device as claimed in claim 2, including recess means into which the ball rolls when it leaves the depression and guide means for guiding the ball into said recess means.
4. A device as claimed in claim 3, wherein thereis a plurality of recess means and guide means for each recess means.
5. A device as claimed in any of claims 2 to 4, comprising a housing providing said depression, recess means and guide means and a closure member through which the depression may be viewed but not the recess means.
6. A device as claimed in claim 1, comprising a tube containing two normally-separated chemical materials which become mixed when the tube is tilted through said predetermined angle and react chemically to provide a visible and permanent indication of the tilt.
7. A device as claimed in claim 1, comprising valve means in an inlet or outlet tube of the meter, which is operated by a gravity-sensitive means so as to close off the valve means as the meter is tilted to said predetermined angle.
8. A device as claimed in claim 7, wherein said gravity-sensitive means comprises a pendulum weight rigidly secured to rotate with a closure valve plate of the valve means.
9. A device as claimed in claim 7, wherein the valve means comprises a flexible tube secured to the inlet or outlet tube at one end and having a free end to which is secured an annular weight.
10. A device as claimed in claim 9, wherein the flexible tube has a waisted area which collapses when the meter is tilted to said predetermined angle.
11. A device substantially as described hereinbefore with reference to Figure 1 or Figures 2 and 3, or Figure 4 or Figure 5 of the accompanying drawings.
12. A gas meter having a device as claimed in any of claims 1 to 11.