1. Field of the Invention
The present invention relates to devices for measuring the weight of an object, and particularly to a portable airbag scale that calculates the weight of an object based on changes in air pressure measurements.
2. Description of the Related Art
Typical weight scales utilize a variety of complex mechanical elements that must remain in balance and alignment in order to provide accurate measurements. For very fine measurements, such as laboratory-scale measurements, the scales typically cannot be moved easily, as even a small mechanical shock will cause imbalance and misalignment of the weighing mechanisms. For large-scale measurements, such as scales utilized to weigh luggage, the scales are typically large enough that transportation thereof is relatively difficult.
Medium-sized scales, such as typical bathroom scales for measuring the weight of a human being, are readily transportable, but are not particularly accurate. It would be desirable to provide a high-accuracy scale that can also be easily transported without the act of transportation causing imbalances and misalignments leading to inaccuracies in measurement.
Thus, a portable airbag scale solving the aforementioned problems is desired.
The portable airbag scale is a scale that measures the weight of a load based upon a difference between measured air pressure within an inflatable bladder. The difference is measured between a first state, where the load is not positioned on the inflatable bladder, and a second state, in which the load is supported on the inflatable bladder.
The portable airbag scale includes an inflatable bladder having opposed upper and lower walls and at least one sidewall. The lower wall thereof is adapted for positioning on a support surface, such as the floor, and the upper wall is adapted for receiving the load to be weighed. A port is formed through the at least one sidewall for selective inflation and deflation of the inflatable bladder.
A pressure sensor is mounted within the inflatable bladder for measuring the air pressure therein. A controller selectively calculates the weight of the load based upon the difference between air pressure in the inflatable bladder measured when the load is not supported on the upper wall, and air pressure in the inflatable bladder measured when the load is supported on the upper wall. A display is provided for displaying the weight of the load.
These and other features of the present invention will become readily apparent upon further review of the following specification.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
The portable airbag scale 10 is a scale that measures the weight of a load based upon a measured difference in air pressure. As best shown in
Any suitable source of air may be used to inflate the inflatable bladder 12, such as a separate air pump, the user's mouth, or the like. The inflatable bladder 12 may be formed from any suitable type of material capable of supporting such loads as a human being, an article of luggage, or the like without popping or tearing, the material being flexible and durable. The inflatable bladder 12 may be constructed in a manner similar to a conventional airbag.
A pressure sensor 40 is mounted within the inflatable bladder 12 for measuring the air pressure therein. A controller 34 (diagrammatically illustrated in
Pressure sensor 40 is preferably a microelectromechanical system sensor (MEMS), although it should be understood that any suitable type of pressure sensor may be utilized. One such barometric amplified pressure sensor is manufactured as part number BARO-A-4V-MINI-MIL by the All Sensors Corporation of Morgan Hill, Calif. This pressure sensor has an output that is ratiometric to the supply voltage and operates between approximately 4.5 and 5.5 V DC. Operating pressures are between approximately 600 and 1,100 mbar.
Based upon the known inflated volume of the inflatable bladder 12 (and the known interior surface area), a processor 36 can calculate the weight of the load based upon the difference in measured air pressure. The pressure sensor 40 first measures the air pressure within the inflated bladder 12, without the load placed on upper wall 26, and this first measurement is stored in memory 38. At this point, an audible tone, such as a beep, is generated to inform the user that the value is stored in memory 38 and that the system is ready for weighing. Once the load has been placed on upper wall 26, the pressure sensor 40 takes a second air pressure measurement, which may also be stored in memory 38, and the processor 36 calculates the difference therebetween and subsequently calculates the weight of the load based upon this difference.
The weight of the load, which may be displayed selectively in pounds or kilograms, is displayed on display 18, which may be a liquid crystal display (LCD) or the like. The display 18 may be attached to the exterior surface of the inflatable bladder 12, as shown in
The processor 36 may be associated with, or incorporated into, any suitable type of computing device, for example, a personal computer or a programmable logic controller. The display 18, the processor 36, the memory 38, and any associated computer readable recording media are in communication with one another by any suitable type of data bus, as is well known in the art. Examples of computer-readable recording media include a magnetic recording apparatus, an optical disk, a magneto-optical disk, and/or a semiconductor memory (for example, RAM, ROM, etc.).
Additionally, a temperature sensor 42 and a humidity sensor 44 may be further provided for respectively measuring the ambient temperature and humidity. Preferably, the display 18 is divided into three separate display regions, as illustrated in
By utilizing an inflatable bladder, the scale 10 is easily transportable. As shown in
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
Number | Name | Date | Kind |
---|---|---|---|
2954221 | Ernst | Sep 1960 | A |
2998089 | Ernst | Aug 1961 | A |
3123165 | Carson, Jr. et al. | Mar 1964 | A |
3371732 | Stein | Mar 1968 | A |
4002216 | Solow | Jan 1977 | A |
4085810 | Wellman | Apr 1978 | A |
4306629 | Powell | Dec 1981 | A |
4431072 | Stepp | Feb 1984 | A |
4542547 | Sato | Sep 1985 | A |
4782905 | Lam | Nov 1988 | A |
4957286 | Persons et al. | Sep 1990 | A |
5092415 | Asano | Mar 1992 | A |
5129472 | Du et al. | Jul 1992 | A |
5234065 | Schmidt | Aug 1993 | A |
5606516 | Douglas et al. | Feb 1997 | A |
5987370 | Murphy et al. | Nov 1999 | A |
6076853 | Stanley | Jun 2000 | A |
6094762 | Viard et al. | Aug 2000 | A |
6504113 | Gallard et al. | Jan 2003 | B2 |
7459645 | Skinner et al. | Dec 2008 | B2 |
7521638 | Godshaw et al. | Apr 2009 | B1 |
7842892 | Wang | Nov 2010 | B2 |
20020134592 | Gray et al. | Sep 2002 | A1 |
20050082094 | Gebert | Apr 2005 | A1 |
20090084609 | Skinner et al. | Apr 2009 | A1 |
20100300768 | Reiter | Dec 2010 | A1 |
Number | Date | Country |
---|---|---|
3834497 | Apr 1990 | DE |
1176826 | Jan 1970 | GB |
Number | Date | Country | |
---|---|---|---|
20110272197 A1 | Nov 2011 | US |