GB1604254A

GB1604254A - Gas pressure warning assembly

Info

Publication number: GB1604254A
Application number: GB2556077A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-05-30
Filing date: 1978-05-30
Publication date: 1981-12-09

Description

(54) GAS PRESSURE WARNING ASSEMBLY (71) I, KENNETH EDBROOKE GREGORY a British Subject of 'Sunnymede', 47 Adbolton Grove, West Bridgford, Nottingham, do hereby declare the invention for which I pray that a Patent may be granted to me and the method by which it is to be performed to be particularly described in and by the following statement: This invention is concerned with a bottled gas supply system and is particularly but not exclusively concerned with a supply system for combustible gas, such as that used by campers and caravaners, boat enthusiasts and such like for cooking, heating and lighting purposes.

Such gas bottles contain a hydro-carbon under pressure for example butane or propane; and the pressure of the gas in bottles may be in the order of 25-lb per square inch. It will be appreciated that such pressure is too high for use for heating or cooking purposes and accordingly a gas pressure regulator is fitted to a bottle so as to maintain the pressure of gas at the users locality at a more practical level for example, 11" of water gauge. The disadvantage for such systems is that the user has no means of knowing when the gas remaining in the bottle is almost consumed, so that he does not know when to replace that bottle with a full one.

According to the present invention there is provided a bottled gas supply system including a bottle of liquified gas having an outlet, connection means releasably connected to said bottle outlet and being adapted for connection to an appliance to which gas is to be supplied the connection means including a gas passageway having an inlet communicating with the bottle outlet and an outlet for communication with the appliance, and pressure sensing means for sensing gas pressure within said passage, th the sensing means forming part of an electrical circuit for providing a signal when the sensing means senses a pressure lower than a predetermined pressure, and indicating means arranged for actuation in response to said signal for providing an indication that said predetermined pressure has been reached.

Reference is now made to the accompanying drawings, in which: Figure 1 is a schematic layout of a first gas bottle supply system according to the present invention; Figure 2 is a sectional view of a first coupling according to the present invention; Figure 3 is a sectional view of a second coupling according to the present invention; Figure 4 is a schematic layout of a second warning system according to the present invention.

Referring initially to Figures 1 and 2, the gas bottle supply system includes an electrical circuit including a battery 10 an on/off switch 11, a pressure sensor 12 and an indicating means 14 which may provide an audible and/or visual signal. The battery 10 is received in a battery holder 16 adapted for mounting on a convenient supply surface, such as a wall, and the indicating means 14 is mounted thereon.

The pressure sensor 12 is mounted on a connection power coupling 20 which has a central bore 21 defining a gas passageway and is provided with a nut 22 at one end for releasable connection to an adaptor 24 which in turn is connected to a bottle 26 containing a liquified gas . The adaptor 24 from an outlet for the bottle 26. The coupling 20 is provided at its other end with a threaded portion 28 for reception of the nut 27 of a pressure regulator 29 which in turn is connected to an appliance (not shown) to be supplied with the gas. The coupling is also provided with a bore 30 communicating with the central bore 21. The pressure sensor is threadedly received in bore 30 and then the coupling serves to provide com- munication between the gas source and the pressure sensor.

As seen more clearly in Figure 2, the pressure sensor includes a diaphragm 32 which is acted upon on one side by gas pressure from the gas source. The diaphragm 32 is arranged to operate a push rod 33 which in turn operates a lever 34 arranged to actuate a micro-switch 35.

In use, when the gas source is at a pressure higher than a predetermined pressure, the diaphragm is deflected upwardly and the push rod engages the lever 34 to hold it in a deflected po.

sition. As the pressure falls the diaphragm will move downwardly causing a similar movement of the push rod and lever. Eventually, when the pressure has reached a predetermined pressure, the lever will operate the switch 35 to cause the electrical circuit to actuate the indicating means to provide a warning signal.

The predetermined pressure is chosen to be slightly above gas pressure emanating from the regulator 29 so that a warning signal is given when a predetermind amount of usable gas remains in the source. Since the pressure of the gas source is dependant on the ambient temperature the amount of usable gas remaining in the gas source also varies with the ambient temperature. The lever 34 is therefore made of a bi-metal construction to compensate for change in ambient temperature.

In Figure 3 an alternative construction of pressure sensor 60 is shown. The pressure sensor 60 is screwed into a bore 1 formed in a coupling 2. The bore 1 houses a plunger having a relatively small surface area 8 integral with a piston head 9 having a relatively larger surface area with slides in the bore 1. The pressure in the bore 1 forces the plunger upwards in the bore 1 and provides pressure within the sensor 60. The sensor 60 comprises a metallic casing 3 having an apertured contact ring 4 located above a flexible diaphragm 7. The diaphragm 7 contacts a metallic button 7a which is biassed by a spring 7b into contact with ring 4. The spring 7b abuts against an insulated capping 7d.

When there is pressure in bore 6 the plunger 8/9 forces the diaphragm 7 to lift and raise button 7a out of contact from ring 4. If the pressure in the bore 6 drops so the pressure on the diaphragm will drop, and an electrical connection is made between button 7a and ring 4.

In Figure 4 there is illustrated a schematic layout of a warning system used for detecting when pressure in a liquified CO2 gas supply has fallen below a predetermined amount. Such a CO2 gas supply may be used for dispensing of beer. The coupling 20 is located between a pair of gas regulators 70, 71; regulator 70 serving to reduce supply pressure from 800 psi to 40 psi and regulator 71 serving to reduce supply press- ure from 40 psi to 26 psi. In this system regulator 70 forms the outlet from bottle 70a containing liquified CO2. The pressure sensor 12 is mounted on a bracket 12a mounted on a wall and is connected to connector 20 via a pipe 20a. The electric circuit is similar to that used for the embodiments described in Figures 1 to 3 with the exception that a rectifier and transformer 75 is provided for supplying electricity at 12 volts to the warning circuit from the A/C domestic mains supply.

WHAT WE CLAIM IS : 1. A bottled gas supply system including a bottle of liquified gas having an outlet, connection means releasably connected to said bottle outlet and being adapted for connection to an appliance to which gas is to be supplied the connection means including a gas passageway having an inlet communicating with the bottle outlet and an outlet for communication with the appliance, and pressure sensing means for sensing gas pressure within said passage, the sensing means forming part of an electrical circuit for providing a signal when the sensing means senses a pressure lower than a predetermined pressure, and indicating means arranged for actuation in response to said signal for providing an indication that said predetermined pressure has been reached.

2. A system according to Claim 1, wherein the pressure sensing means comprises a diaphragm which is arranged to be acted upon on one side by gas pressure from said passageway, the diaphragm being arranged to operate switch means for providing said signal.

3. A system according to Claim 2, wherein the diaphragm operates the switch means via an actuating mechanism which is responsive to change in temperature so as to compensate for change in gas pressure caused by the change in temperature.

4. A system according to Claim 3, wherein the diaphragm is arranged to deflect a lever arranged to operate the switch means, the lever being of a bi-metal construction.

5. A system according to any of Claims 2 to 4, wherein the diaphragm is isolated from direct communication with said gas source by a plunger.

6. A system according to any preceding claim, wherein electrical source for the electric circuit is a battery, a battery holder being provided adapted for attachment to a support surface.

7. A system according to Claim 6, wherein the indicating means is mounted on said holder.

8. A system according to any preceding claims wherein the indicating means provides an audible signal.

9. A system according to any preceding claim, wherein the indicating means provide a visual signal.

10. A gas pressure warning assembly substantially as described with reference to and as illustrated in any of the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the lever will operate the switch 35 to cause the electrical circuit to actuate the indicating means to provide a warning signal. The predetermined pressure is chosen to be slightly above gas pressure emanating from the regulator 29 so that a warning signal is given when a predetermind amount of usable gas remains in the source. Since the pressure of the gas source is dependant on the ambient temperature the amount of usable gas remaining in the gas source also varies with the ambient temperature. The lever 34 is therefore made of a bi-metal construction to compensate for change in ambient temperature. In Figure 3 an alternative construction of pressure sensor 60 is shown. The pressure sensor 60 is screwed into a bore 1 formed in a coupling 2. The bore 1 houses a plunger having a relatively small surface area 8 integral with a piston head 9 having a relatively larger surface area with slides in the bore 1. The pressure in the bore 1 forces the plunger upwards in the bore 1 and provides pressure within the sensor 60. The sensor 60 comprises a metallic casing 3 having an apertured contact ring 4 located above a flexible diaphragm 7. The diaphragm 7 contacts a metallic button 7a which is biassed by a spring 7b into contact with ring 4. The spring 7b abuts against an insulated capping 7d. When there is pressure in bore 6 the plunger 8/9 forces the diaphragm 7 to lift and raise button 7a out of contact from ring 4. If the pressure in the bore 6 drops so the pressure on the diaphragm will drop, and an electrical connection is made between button 7a and ring 4. In Figure 4 there is illustrated a schematic layout of a warning system used for detecting when pressure in a liquified CO2 gas supply has fallen below a predetermined amount. Such a CO2 gas supply may be used for dispensing of beer. The coupling 20 is located between a pair of gas regulators 70, 71; regulator 70 serving to reduce supply pressure from 800 psi to 40 psi and regulator 71 serving to reduce supply press- ure from 40 psi to 26 psi. In this system regulator 70 forms the outlet from bottle 70a containing liquified CO2. The pressure sensor 12 is mounted on a bracket 12a mounted on a wall and is connected to connector 20 via a pipe 20a. The electric circuit is similar to that used for the embodiments described in Figures 1 to 3 with the exception that a rectifier and transformer 75 is provided for supplying electricity at 12 volts to the warning circuit from the A/C domestic mains supply. WHAT WE CLAIM IS :

1. A bottled gas supply system including a bottle of liquified gas having an outlet, connection means releasably connected to said bottle outlet and being adapted for connection to an appliance to which gas is to be supplied the connection means including a gas passageway having an inlet communicating with the bottle outlet and an outlet for communication with the appliance, and pressure sensing means for sensing gas pressure within said passage, the sensing means forming part of an electrical circuit for providing a signal when the sensing means senses a pressure lower than a predetermined pressure, and indicating means arranged for actuation in response to said signal for providing an indication that said predetermined pressure has been reached.