Apparatus for measuring gas contents in a gas bottle

Abstract

The invention provides an apparatus for measuring the gas content of a gas bottle by weighing it. The apparatus includes a rigid housing with a platform supporting the bottle, a load cell to measure weight, and a microcontroller for data processing. The platform is designed to be placed under one side of the bottle, measuring a fraction of the total weight, which is then processed to calculate the gas content. The apparatus compensates for tilt, offset, and temperature variations to ensure accurate measurements. The microcontroller also allows the user to select tare weights for different gas bottle configurations and adjust the display to show the gas content as a percentage of the total gas remaining. This design provides a simple, low-cost, and portable solution for accurately determining gas bottle contents, making it ideal for use in the gas retail and refilling industry.

Description

APPARATUS FOR MEASURING GAS CONTENTS IN A GAS BOTTLEFIELD OF THE INVENTION

[0001] This invention relates to weighing devices for accurately determining the remaining liquid contents of symmetrical gas bottles using partial load measurement with automatic compensation for load cell offset, tilt, temperature, and tare weight.BACKGROUND OF THE INVENTION

[0002] Existing methods for weighing gas bottles typically require the entire bottle to be placed on a traditional multi-load cell scale, which can be cumbersome and impractical due to the weight of the bottle and correct placement on the weighing apparatus.

[0003] Alternatively, some methods involve pouring hot water over the side of the container to highlight the condensation where the liquid level ends, requiring the gas to run for approximately five minutes. Hence, it becomes cooler inside the container.

[0004] Another approach is to use a temperature strip placed on the side of the bottle to indicate the level of the cold gas, which similarly necessitates running the gas for ten minutes before a reading can be taken and which requires separate indicators for winter and summer conditions and is influenced by the ambient temperature of the environment.

[0005] Another approach is an ultrasonic level checker with a working temperature ceiling of 40 degrees Celsius, which is not recommended for refillable gas bottles, rusty gas bottles, and gas bottles with thick paint layers.

[0006] These ultrasonic devices do not directly weigh an object but interpret ultrasonic signals into equivalent weights. Furthermore, ultrasonic devices are high cost and can be complex to configure correctly for the variety of gas bottle sizes and quick turnover rate for refilling.

[0007] Additionally, some gauges connect to the LPG outlet pipe, measuring the internal pressure of the space in the bottle to estimate the remaining contents. However, all these methods are sensitive to temperature limits and fluctuations, leading to inaccurate readings which do not self-adjust for ambient temperature and do not use the industry standard of measuring LPG by weight; they check the level of the gas within the gas bottle without any compensation for expansion or contraction of the gaseous contents due to ambient temperature fluctuations.

[0008] The present invention at least partially addresses the problem.SUMMARY OF INVENTION

[0009] The invention provides an apparatus for measuring a gas content within a gas bottle, which includes: a housing which extends in an axial direction between an upper end and a base end,a platform extending from the housing at the base end in a direction perpendicular to the axial direction, configured to fit beneath a bottom edge section of the gas bottle, and providing a first load-bearing surface configured to support a portion of the gas bottle's weight and transfer it to the base end, a positioning projection engaged to a side of the housing, configured to abut a side of the gas bottle when the load-bearing platform is positioned beneath the gas bottle and the housing is optimally positioned relative to the gas bottle, a weight sensor positioned at the base end, configured to measure the portion of the weight, a microcontroller within the housing in communication with the weight sensor, configured to calculate the gas content based on the portion of the weight.

[0010] The microcontroller may be further configured to calculate the gas content of the gas bottle based on the portion of the weight and one or more of the following inputs: the angle of inclination between the floor and the bottom edge section of the gas bottle (“tilt factor”), the distance between the housing and an outer circumference of the gas bottle (“offset factor”), the ambient temperature, and the tare weight of the gas bottle.

[0011] The apparatus may include a temperature sensor in the housing configured to measure the ambient temperature and transmit the measurement to the microcontroller.

[0012] The apparatus may include a display positioned at the upper end of the housing, in communication with the microcontroller, and configured to display a reading associated with the gas content.

[0013] Alternatively, or in addition, the apparatus may include a transceiver mounted on or within the housing, in communication with the microcontroller, and configured to transmit a reading associated with the gas content to a receiving device.

[0014] The apparatus may include a user interface positioned at the upper surface of the housing, in communication with the microcontroller, and configured for input from a user of a tare weight or a selection of units of the gas content reading.

[0015] The positioning projection may include a second load-bearing surface configured to support a portion of the gas bottle’s weight and transfer it to the base end.

[0016] The housing may include a slot extending in the axial direction, configured to engage the positioning projection, allowing the projection to move along the slot and abut a gas bottle of any configuration.

[0017] The slot may be configured to fictionally engage the positioning projection, preventing the projection from moving downwardly along the slot, once the projection is in place and abutting the gas bottle.BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention is further described by way of an example with reference to the accompanying drawings in which:Figure 1 is an isometric view from above of an apparatus for measuring a gas content within a gas bottle in accordance with the invention; Figure 2 is an isometric view from below of the apparatus of Figure 1 ;Figure 3 is a view in elevation from a first side of the apparatus;Figure 3a presents a partial cross-sectional view of the apparatus housing;Figure 4 is a view in elevation from a second side of the apparatus;Figure 5 is a view in plan of the apparatus; Figure 6 is a view in under plan of the apparatus;Figure 7 is a partial view in elevation of the apparatus engaged with a gas bottle of a first configuration;Figure 8 is a partial view in elevation of the apparatus engaged with a gas bottle of a first configuration; Figure 9 schematically illustrates the apparatus, showing the electronic components housed within the apparatus.DESCRIPTION OF PREFERRED EMBODIMENTS

[0019] Figures 7 and 8 illustrate an apparatus 10 for measuring gas contents within a gas bottle 12, in accordance with the invention.

[0020] Referring to Figures 1 and 2, apparatus 10 includes a rigid tubular body 14, which extends in an axial direction, between an operatively upper and 16 and an opposed base end 18, and a platform 18, which extends perpendicular to the axial direction.

[0021] The housing 10 is formed with an exterior axially aligned slot 22, which extends between the ends (16, 18). A positioning projection 24 is mounted within the slot and moveable within the slot operatively upwardly or downwardly to position the projection, as will become apparent below.

[0022] A load cell weight sensor 26 is mounted within housing 14 at the base end 18, while a digital screen 28 is positioned at the upper end of the housing, ensuring visibility to the user.

[0023] Referring to Figure 9, apparatus 10 features a microcontroller 30 housed within the housing and electronically connected to the weight sensor 26 and screen 28. The microcontroller, along with the supporting electronic circuitry, is powered by a battery 32.

[0024] As shown in Figures 7 and 8, apparatus 10 measures the gas contents of the bottle (12.1 , 12.2) by weighing it. The process involves lifting one side of the gas bottle and sliding platform 20 beneath a circular base edge 34 of the bottle’s foot ring 42. Positioning the platform beneath only one side, the apparatus measures a fraction (typically half) of the total weight. The microcontroller then processes this partial load measurement, compensating for the partial load and any tilt of the gas bottle due to the platform's positioning. The microcontroller calculates the actual weight of the gas bottle,subtracting the tare weight and accommodating tilt and offset factors, which will be discussed below, to determine the gas contents. This principle effectively enables an accurate weight estimate for symmetrical objects like gas bottles.

[0025] To achieve optimal positioning, with the appropriate lateral or working offset distance (denoted as X in Figures 7 and 8, representing the distance between the outer surface of the main body portion 40 of the bottle and the central axis line of the housing), the positioning projection 24 is adjusted along slot 22 to contact an outer surface 38 of the gas bottle. This ensures the apparatus 10 is accurately aligned relative to the bottle 12, allowing it to measure the gas bottle’s weight with the precision for which the apparatus is designed. In doing so, the positioning projection fulfils one of its primary functions: relative positioning.

[0026] The axial positioning of projection 24 varies depending on the configuration of the gas bottle 12. As illustrated in Figures 7 and 8, bottle 12.1 in Figure 7 features the main body portion 40 with a circumference equivalent to the foot ring 42. In contrast, the bottle 12.2 in Figure 8 has a recessed foot ring with a smaller circumference than the main body portion. In each case, the positioning projection is adjusted to abut the appropriate part of the bottle to accommodate its specific design.

[0027] The apparatus 10 is designed so that, when used with the type of bottle 12.1 shown in Figure 7, the positioning projection 24 extends into the annular recess 44, separating the main body portion 40 from the foot ring 42.This orientation indicates the optimal positioning of the apparatus for this type of bottle.

[0028] For bottle 12.2, shown in Figure 8, the optimal positioning is indicated when the positioning projection is moved up slot 22 into contact with the convex surface of the main body portion 40, where the circumference gradually decreases towards the foot ring.

[0029] It is anticipated that the apparatus will include instructions guiding the user on how to orient the positioning projection 24 for a specific gas bottle configuration. The critical aspect of this positioning is maintaining a working offset distance of 2 to 3 mm from the gas bottle sidewall. When positioned within this range, the lateral offset will be accounted for in the gas bottle content calculation, as described below, ensuring no significant discrepancy between the calculated and actual weight.

[0030] In both examples, the nose-end 46 or the upper-facing load-bearing surface 48 of the positioning projection 24 makes contact with the gas bottle. This contact maintains the rigidity of the apparatus, preserving the perpendicular L shape when the platform is placed beneath the gas bottle.

[0031] By establishing a physical contact point between apparatus 10 and gas bottle 12, the load-stabilizing projection prevents flexing of the apparatus when the gas bottle is positioned atop the platform and weight is applied. Flexing typically occurs at the junction of housing 14 and platform 20, where inward movement could distort the weight measurement. This contact ensures that the partial weight of the bottle is accurately transferred through theapparatus to the base end 18, maintaining force conservation and preventing load loss due to structural deformation. Ultimately, the weight sensor 26 receives the correct partial load measurement, ensuring precise results without distortion from flexing.

[0032] The positioning projection 24 must be easily movable along track 22 by the user but must lock securely in place when positioned and subjected to the weight of the gas bottle 12, preventing downward movement. This is achieved through a specific configuration of the positioning projection and the complementarily formed slot 22, as illustrated in Figure 3a. The positioning projection includes a projecting part 70 that extends from the slot and an engaging part 72, shaped like an anvil, engaging the slot. The engaging part features lateral rails 74.1 and 74.2, which engage with undercut tracks 76.1 and 76.2 running along each side of the track. This configuration creates a frictional engagement between the positioning projection and the track. When a downward force from the gas bottle is applied, the projection tilts forward slightly, causing a misalignment between the rails and tracks, which locks the projection in place.

[0033] The positioning projection 24 becomes particularly significant in the preferred embodiment of the invention, where the platform 20 is constructed from multiple wire elements, designated 50.1 , 50.2, 50.3, and 50.4, that extend in a planar array to form the load-bearing surface. Using wireforms for the platform is advantageous as it reduces the platform's profile, thereby minimising the tilt of the gas bottle 12. However, in this configuration of discrete wire elements, the weight of the bottle may cause the wire-basedplatform to bend, potentially distorting the rigid L-shape of the apparatus and compromising its performance. This underscores the importance of the positioning projection 24. To improve platform rigidity and minimise distortion and lateral flexing, the wire elements can be interconnected or fabricated as a single continuous wireform.

[0034] The radial offset and the overhanging configuration of the gas bottle 12.2 results in the upper-facing load-bearing surface 48 of the positioning projection 24, providing complementary support to the load applied on the platform. This design ensures that the partial weight of the gas bottle is directed perpendicularly through the apparatus's load-bearing surface 10, efficiently transferring the load to the base end 18. Receiving the load perpendicularly is critical to ensure accurate weight transfer, minimise structural deformation, and maintain stability by avoiding shear stresses or lateral forces.

[0035] As outlined above, factors such as tilt, resulting from lifting one side of the gas bottle 12 to position the platform 20 beneath it, and load cell offset, which arises when the load cell 26 is not perfectly aligned with the load, must be addressed in the final calculation to accurately determine the gas content weight (excluding the gas bottle tare). A temperature correction factor must also be applied because the load cell's accuracy varies with temperature. In this example, tilt and offset factors are not directly measured but are instead preprogrammed as averaged values within the microprocessor’s code. In contrast, temperature is a measured parameter, recorded by a temperature sensor 60 and input into the microcontroller for processing.

[0036] The apparatus includes a microcontroller 30 (including processing and volatile and non-volatile memory components), a temperature sensor 60, an amplifier 62, an analogue-to-digital converter 64, and a power regulation circuit (not illustrated), all integrated into a printed circuit board (PCB) 66 mounted within the housing 14. The PCB may also incorporate a transceiver 68, though, in Figure 9, the transceiver is shown separately for clarity of illustration.

[0037] The microcontroller’s memory is preprogrammed with a range of tare weights corresponding to various gas bottle configurations and sizes, along with the associated tilt and offset factors. Using the select button 56, the user can navigate through the available tare weight options displayed on screen 28. Once the correct tare weight for gas bottle 12 is identified, the user confirms the selection by pressing the enter button 58. This action saves the selected tare weight to non-volatile memory, ensuring it is retained even when the device is powered off or the battery is replaced. The user can easily select an alternative tare weight from the preprogrammed options if a different gas bottle is introduced.

[0038] After being amplified and digitally converted, the microcontroller receives temperature measurements from the temperature sensor 60 and weight measurement signals from the load cell 26. The microcontroller is programmed with a suitable algorithm to apply compensation for tilt and offset factors, subtract the tare value, account for temperature variations, and use the partial load measurement principle (doubling the weight measured by theload cell) to calculate the gas content weight in the gas bottle. The resulting calculation is then displayed on the screen 28.

[0039] A simple weight measurement of the gas contents may not be helpful to the user. What is more practical is having this information represented as a percentage of the total gas remaining, enabling the user to estimate, for example, how much longer he can cook before the gas runs out. Using interface buttons 56 and 58, the user can customise how the information is displayed, including selecting the preferred unit (Kgs or Lbs) or choosing whether to display the information graphically on screen 28. By scrolling through the available options and selecting their preference, the user can tailor the display to suit his needs.

[0040] The transceiver can transmit the gas content reading to a user's handheld device or laptop via an appropriate transmission protocol, such as WiFi or Bluetooth. Conversely, the user can interact with the apparatus by inputting tare weight, selecting the gas content display options through their device, and communicating with the apparatus.

[0041] The apparatus 10 provides a simple, low-cost solution that aligns with industry standards by using weight as the sole measure, eliminating the need for temperature or level-based measurements. Its working principle relies on Partial Load Measurement, weighing only half the gas bottle by placing the device under one edge. This design enhances ease of use and portability.

[0042] The apparatus lets users tilt the gas bottle slightly and position it beneath one side, streamlining the weighing process. This feature mainlybenefits weaker or infirm users, removing the need to lift the entire bottle. It is also ideal for weighing gas bottles in confined spaces or enclosures where traditional scales or lifting the bottle fully would be difficult.

[0043] Designed to accommodate any symmetrically shaped gas bottle (see Figures 7 and 8), apparatus 10 simplifies the weighing process for various sizes and forms. It enables users to determine gas bottle contents using the industry-standard weight measure, avoiding the complexities of temperature or pressure-sensitive methods.

[0044] By leveraging weight — the industry standard for gas sales — the compact and portable design of the apparatus makes it a valuable tool for the gas retail and refilling industry.

Claims

CLAIMS1 . An apparatus for measuring a gas content within a gas bottle, which includes a housing which extends in an axial direction between an upper end and a base end, a platform extending from the housing at the base end in a direction perpendicular to the axial direction, configured to fit beneath a bottom edge section of the gas bottle, and providing a first load-bearing surface configured to support a portion of the gas bottle's weight and transfer it to the base end, a positioning projection engaged to a side of the housing, configured to abut a side of the gas bottle when the load-bearing platform is positioned beneath the gas bottle and the housing is optimally positioned relative to the gas bottle, a weight sensor positioned at the base end, configured to measure the portion of the weight, a microcontroller within the housing in communication with the weight sensor, configured to calculate the gas content based on the portion of the weight.

2. An apparatus according to claiml wherein the microcontroller is configured to calculate the gas content of the gas bottle based on the portion of the weight and one or more of the following inputs: the angle of inclination between the floor and the bottom edge section of the gas bottle, the distance between the housing and an outer circumference of the gas bottle, the ambient temperature, and the tare weight of the gas bottle.

3. An apparatus according to claim 1 or 2 which includes a temperature sensor in the housing configured to measure the ambient temperature and transmit the measurement to the microcontroller.

4. An apparatus according to anyone of claims 1 to 3 which includes a display positioned at the upper end of the housing, in communication with the microcontroller, and configured to display a reading associated with the gas content.

5. An apparatus according to anyone of claims 1 to 4 which includes a transceiver on or within the housing, in communication with the microcontroller, and configured to transmit a reading associated with the gas content to a receiving device.

6. An apparatus according to any one of claims 1 to 5 which includes a user interface positioned at the upper surface of the housing, in communication with the microcontroller, and configured for input from a user of a tare weight or a selection of units of the gas content reading.

7. An apparatus according to anyone of claims 1 to 6 wherein the positioning projection includes a second load-bearing surface configured to support a portion of the gas bottle’s weight and transfer it to the base end.

8. An apparatus according to anyone of claims 1 to 7 wherein the housing includes a slot extending in the axial direction, configured to engage the positioning projection, allowing the projection to move along the slot and abut a gas bottle of any configuration.

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