GB2592210A

GB2592210A - A U-tube manometer gas pressure gauge

Info

Publication number: GB2592210A
Application number: GB2002267.9A
Authority: GB
Inventors: Gregson Brian
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-02-19
Filing date: 2020-02-19
Publication date: 2021-08-25
Also published as: GB202002267D0

Abstract

The present invention relates to a U gauge manometer comprising: a transparent U-tube 16, 18 to contain a liquid and a scale having a series of numerals linearly arranged along the scale. The scale is positioned adjacent to the arms of the tube to indicate a position along the arms of the tube. A connection at the end of a first arm of the U-tube is provided to connect to a pressure source. A vent is provided at the end of the second arm open to atmosphere. A light source is 24 configured to illuminate the scale and a light source positioned outside the tube and configured to illuminate the interior of the tube. The scale may be placed on sheet of transparent material and light transmitted by total internal reflection through the material to illuminate the scale markings. The whole device may be provided with a foot 36 so it may stand upright.

Description

A U-tube manometer gas pressure gauge

Field of the Invention

The present invention relates to manometer style gas pressure gauges and in particular to an improved gauge with enhanced visibility of the pressure scale.

Background

Manometers to indicate gas pressure as for example in a domestic gas supply typically comprise a liquid in a U-shaped tube, gas pressure being indicated by depression of the level of liquid in a first arm of the tube to which the gas supply is connected, versus that in the other arm, which is open to atmospheric pressure. The pressure is read from a scale provided alongside the tube. Such manometers need to be read when upright and are often used in dark and confined spaces. Conventional U-tube manometers are difficult to use in such circumstances and improvements are needed.

Prior Art

Accordingly, a number of patent applications have been filed in an attempt to resolve the problem or similar, including the following: GB-804424 discloses a pressure indicating instrument comprising a U-tube manometer containing a translucent liquid, an optical projection system for directing light on to one limb of the manometer on both sides of the liquid surface in that limb and a photoelectric cell connected to an instrument for measuring its output, the cell being located so that light from the projection system is focused by the liquid in the limb of the manometer to form an elongated image on the cell the length of which varies with the position of the liquid surface and causes a variation in the output of the cell.

This device is typical of a whole class of designs that aim to improve usability of U-tube manometers by including an electronic readout system. In general such devices 35 are complex to manufacture and are an electronic readout is unnecessary to solve the basic problem of usability for a simple, low-cost device.

US2303121 discloses: In a manometer, the combination of an upright transparent tube having a scale thereon, a relatively opaque conducting liquid pressure responsive to rise in the tube, an electric lamp located inside the tube to illuminate the tube and liquid surface, an electric circuit electrically connected with the lamp and said liquid, and a terminal interposed in said electric circuit extending inside the tube to be engaged by said liquid when elevated a predetermined distance in the tube to close the circuit.

Again, this device is a member of the class of electrical or electronic readout devices, but in this case applies an additional feature, of illumination of the liquid within the tube in order to make readout by eye easier. However, the design of providing a light source inside the tube is inherently unreliable, for example if the manometer is tilted, and unnecessarily complex.

In contrast the present invention provides a simple, improved U-tube manometer with features to allow easy reading of the liquid level by eye.

Summary of the Invention

According to the present invention there is provided a U gauge manometer comprising: a U shaped transparent tube to contain a liquid, a scale having a series of numerals linearly arranged along the scale, the scale being positioned adjacent to the two arms of the tube to indicate a position along the arms of the tube, a connection at the end of a first arm of the U shaped tube to connect to a pressure source, a vent at the end of the second arm open to atmosphere, a light source configured to illuminate the scale, and a light source positioned outside the tube and configured to illuminate the interior of the tube.

In some embodiments the manometer comprises a single light source configured to 35 illuminate both the scale and the interior of the tube.

In some embodiments the manometer comprises a first light source configured to illuminate the scale, and a second light source positioned outside the tube and configured to illuminate the interior of the tube.

In a preferred embodiment a light source may be arranged behind the scale so that the scale glows in order to illuminate the numerals included on the scale. For example a strip of lights, or single strip light may be arranged along the length of the scale.

In an alternative embodiment a light source is mounted externally on the device and directed to illuminate the scale Preferably a light source is an LED. Herein light sources will be referred to as LEDs, though light sources are not limited to LEDs and may comprise other electrically 15 powered light sources.

The device comprises a liquid in use. The device may comprise a liquid filled into and retained within the U shaped tube. The tube may comprise a liquid-tight and gas permeable seal at each end of the tube, to retain the liquid within the tube but to 20 allow gas to move into and out from each end of the tube to cause pressure of gas to move the liquid. Such a seal may comprise a narrow tube, aperture or orifice, optionally adapted to be non-wettable by the liquid, and may comprise a porous material that is non-wettable by the liquid. The liquid may be aqueous or non-aqueous. The liquid is preferably dyed or otherwise configured to be visible through the tube. The liquid may comprise pigment or a fluorescent material.

In some embodiments the scale comprises a partially translucent elongated sheet member having scale markings thereon, and the light source comprises a plurality of light sources, such as LEDs, arranged along the length of the scale and behind the sheet member. In this way the LEDs are arranged to shine through the partially translucent sheet member to illuminate the scale markings and also to illuminate the first and second arms of the tube.

In some embodiments the sheet member comprises a transparent material and the 35 light source comprises one or more sources, such as LEDs, arranged at a first end of the sheet member such that light is transmitted along the sheet member by total internal reflection, as known in the art. In such embodiments the scale markings are configured to couple light out of the sheet member at the markings, so as to illuminate the markings. Such markings may be roughened or indented with respect to the remainder of the front surface of the sheet member, such that light is coupled preferentially out of the sheet at the markings.

In some such embodiments an edge of the sheet member is aligned adjacent to an arm of the tube, and the edge is configured to allow light to couple out of the edge to illuminate the arm of the tube.

In this way a light source at a single location, such as at the base of the manometer, may illuminate both the scale and the arms of the tube, by means of light transmission along the scale sheet member by total internal reflection.

The manometer comprises a body to support the tube, scale and connections, a battery to power the light source(s), and a switch to control the light sources. The manometer may be configured to stand upright on its base, such that the tube and scale are substantially vertical, and the body may have an enlarged region at the base to provide a foot on which the manometer may stand The manometer may comprise a zero adjuster component, arranged to slide along the length of the scale, and having a friction means to retain it in position relative to the scale when not being moved.

Brief Description of Figures

Figure 1 shows a rear isometric view of an embodiment of the invention. Figure 2 shows a front isometric view of the embodiment shown in figure 1. Figure 3 shows a front exploded view of the embodiment shown in figure 1. 30 Figure 4 shows a rear exploded view of the embodiment shown in figure 1.

Detailed Description of Figures

Referring to figures 1 to 4, an embodiment of a U gauge manometer according to the 35 invention comprises: a U shaped transparent tube 10 to contain a liquid, a scale 12 having a series of numerals 14 linearly arranged along the scale, the scale being positioned adjacent to the two arms 16, 18 of the tube to indicate a position along the arms of the tube, a connection 20 at the end of a first arm 16 of the U shaped tube to connect to a pressure source, a vent 22 at the end of the second arm 18 open to atmosphere, a light source 24 configured to illuminate the scale, and a light source positioned outside the tube and configured to illuminate the interior of the tube.

In this embodiment the manometer comprises a single light source 24 configured to illuminate both the scale and the interior of the tube.

In this embodiment the scale 12 comprises a partially translucent elongated sheet member 26 having scale markings 14 thereon, and the light source 24 comprises a plurality of LEDs 28 arranged along the length of the scale and behind the sheet member. In this way the LEDs are arranged to shine through the partially translucent sheet member to illuminate the scale markings and also to illuminate the first and second arms of the tube.

The manometer comprises a housing body 30 to support the tube, scale and connections, a battery 32 to power the LEDs 28, and a switch 34 to control the light sources. The manometer is configured to stand upright on its base 35, such that the tube and scale are substantially vertical, and the body has an enlarged region 36 at the base to provide a foot 38 on which the manometer may stand.

The manometer comprises a zero adjuster component 40, arranged to slide along the length of the scale, and having a friction means to retain it in position relative to the scale when not being moved. The zero adjuster component is operable by means of a button 42 at the rear of the device that may be moved along the length of the device.

The device may be formed from materials as known in the art. The tube may be transparent plastic, the body, scale, connections and zero adjuster may be formed 35 from moulded plastic. The LEDs 28 are provided on a LED strip 44.

Referring to the exploded diagrams in figures 3 and 4, the embodiment may comprise the following components: a housing body 30 comprising a first housing component 46 to retain the U shaped tube and light source, a second housing component 48 that interfits removably with the first housing component to form the base 35 of the device and that accommodates the battery, a control board 50 comprising a battery holder 52, the switch 34 and optionally other components, for example to adjust the brightness of the LEDs (electrical connections between the control board and the LEDS strip 44 are not shown), a switch button 54 to operate the switch, mounted through an aperture in the first housing component, a transparent front fascia 56 to protect the U shaped tube, and a housing closure 58 comprising a hanging tag.

The U shaped tube contains an indicator liquid, such as a red-dyed oil, in use.

The invention has been described by way of examples only and it will be appreciated that variation may be made to the above-mentioned embodiments without departing from the scope of invention. Firstly it will be understood that any features described in relation to any particular embodiment may be featured in combinations with other embodiments.

With respect to the specification therefore, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of the principles of the invention, with variation and implementation obvious and clear on the basis of either common general knowledge or of expert knowledge in the field concerned. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as set out in the accompanying claims.

Claims

Claims 1 A U gauge manometer comprising: a U shaped transparent tube to contain a liquid, a scale having a series of numerals linearly arranged along the scale, the scale being positioned adjacent to the two arms of the tube to indicate a position along the arms of the tube, a connection at the end of a first arm of the U shaped tube to connect to a pressure source, a vent at the end of the second arm open to atmosphere, a light source configured to illuminate the scale, and a light source positioned outside the tube and configured to illuminate the interior of the tube.
2. A manometer according to claim 1 comprising a light source configured to illuminate both the scale and the interior of the tube.
3. A manometer according to claim 1 comprising a first light source configured to illuminate the scale, and a second light source positioned outside the tube and configured to illuminate the interior of the tube.
4. A manometer according to any preceding claim comprising a dyed liquid filled into and retained within the U shaped tube and a liquid-tight and gas permeable seal at each end of the tube, to retain the liquid within the tube but to allow gas to move into and out from each end of the tube to cause pressure of gas to move the liquid.
5. A manometer according to any preceding claim wherein the scale comprises a partially translucent elongated sheet member having scale markings thereon, and the light source comprises a plurality of light sources arranged along the length of the scale and behind the sheet member.
6. A manometer according to any of claims 1 to 4 wherein the sheet member comprises a transparent material and the light source comprises one or more sources arranged at a first end of the sheet member such that light is transmitted along the sheet member by total internal reflection to illuminate the scale markings.
7. A manometer according to claim 6 wherein an edge of the sheet member is aligned adjacent to an arm of the tube, and the edge is configured to allow light to couple out of the edge to illuminate the arm of the tube.
8. A manometer according to any preceding claim configured to stand upright on its base such that the tube and scale are substantially vertical, the body comprising an enlarged region at the base to provide a foot on which the manometer may stand.
9. A manometer according to any preceding claim comprising a zero adjuster component, arranged to slide along the length of the scale, and having a friction means to retain it in position relative to the scale when not being moved.