GB2107068A - Gas meters - Google Patents

Abstract

A domestic gas meter includes means for cutting off the gas supply when the meter is tilted more than a predetermined angle from the upright n position. The means may comprise a butterfly valve (34) in the inlet or outlet tube (35) of the meter. A pendulum weight (36) rigidly fixed to rate with the valve holds the valve open when the meter is upright but progressively closes it as the meter is tilted. Another device reduces gas flow by the collapsing of a portion of a pendulous length of a flexible sleeve weighted at its lower end so as to be gravity-sensitive. <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-forth 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 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, Figure 2 is a diagrammatic representation of a gas flow restrictor for the gas meter of Figure 1 in two positions, and Figure 3 is a side view of another form of gas flow restrictor for the gas meter of Figure 1.

Referring first to Figure 1, a domestic dry gas meter (11) is of the kind in which the back-andforth 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.

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 2 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 3 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 of 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 ensure 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

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 limit the flow of gas through the meter while it is so tilted.

2. A device as claimed in claim 1, comprising valve means in an inlet and 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.

3. A device as claimed in claim 2, wherein said gravity-sensitive means comprises a pendulum weight rigidly secured to rotate with a closure valve plate of the valve means.

4. A device as claimed in claim 2, 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.

5. A device as claimed in claim 4, wherein the flexible tube has a waisted area which collapses when the meter is tilted to said predetermined angle.

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

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. 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-forth 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 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, Figure 2 is a diagrammatic representation of a gas flow restrictor for the gas meter of Figure 1 in two positions, and Figure 3 is a side view of another form of gas flow restrictor for the gas meter of Figure 1. Referring first to Figure 1, a domestic dry gas meter (11) is of the kind in which the back-andforth 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. 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 2 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 3 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 of 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 ensure 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

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 limit the flow of gas through the meter while it is so tilted.

2. A device as claimed in claim 1, comprising valve means in an inlet and 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.

3. A device as claimed in claim 2, wherein said gravity-sensitive means comprises a pendulum weight rigidly secured to rotate with a closure valve plate of the valve means.

4. A device as claimed in claim 2, 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.

5. A device as claimed in claim 4, wherein the flexible tube has a waisted area which collapses when the meter is tilted to said predetermined angle.

6. A device substantially as described hereinbefore with reference to Figure 1 in conjunction with Figure 2 or Figure 3 of the accompanying drawings.

7. A gas meter having a device as claimed in any of claims 1 to 6.