Gas tank gauge

A device for measuring and indicating the volume of the contents of a tank includes a fixed base. A spring deflectable with to the base is also provided. The spring supports at least a portion of the tank weight. A visible connector is connected to the spring such that movement of the visible indicator is coupled to movement of the spring. Thus, as the deflection in the spring changes with an increase or decrease in the tank weight, the indicator moves to reflect the change in tank weight.

FIELD OF THE INVENTION

The present invention relates to gauges. More specifically, the present invention relates to a gauge that indirectly measures and indicates the volume of the contents of a tank by measuring the tank weight.

BACKGROUND OF THE INVENTION

Many appliances operate using liquid or gas fuel. For example, many home grills operate using liquified propane stored in pressurized tanks. A problem arises, however, because the tanks are often opaque containers. Thus, the volume stored in the tank cannot be visually discerned. While some appliances using such tanks include a pressure gauge, many do not. Thus, in a conventional appliance, there is typically no readily discernable way to determine the volume of the contents of the tank.

A number of inventions have been created to address this problem. Most use a method and device in which a spring is biased against a tilted tank. As the tank empties, the weight decreases and the spring causes the tank to tilt in the opposite direction.

One drawback of this type of system is that no indicator is given and the user is expected to understand the significance of the tilted tank. Also, this type of system is prone to inaccurate readings if the pivot around which the tank tilts sticks or otherwise cannot rotate freely. Additionally, the amount of tilt may inaccurately reflect the quantity contained in the tank if the tank is improperly positioned on the system because the amount of tilt will depend on the length of the moment arm around the pivot.

SUMMARY OF THE INVENTION

The present invention measures and indicates the volume of the contents of a tank. By way of definition, “tank weight” as used herein refers to the weight of the tank plus the weight of the contents of the tank. The device includes a fixed base. It should be noted that the base may be fixed by resting on a horizontal surface or by mounting it to a horizontal or vertical surface. For example, it is contemplated that the base may rest on a ground surface, be mounted to a wall or gas appliance support, or the like. Optionally, the base cooperates with a cover to enclose the tank. The base may further include rollers, optionally retractable rollers, and a handle. Also provided is a spring deflectable with respect to the base. The spring supports at least a portion of the tank weight. Optionally, the spring supports the entire tank weight. In one embodiment, the base is mounted to a wall surface and the spring supports and suspends the tank. While the tank may rest directly on the spring, a cradle attached to the spring may be provided to support and receive the tank.

A visible indicator is connected to the spring such that the indicator moves in some fashion with respect to the fixed base when the spring deflects under the tank weight. The indicator moves between a first position, in which the spring is at a first deflection under a first tank weight when the tank holds a first volume of contents, and a second position, in which the spring is at a second deflection under a second tank weight less than the first tank weight when the tank holds a second volume of contents. In other words, as the tank weight changes, the deflection of the spring changes thereby changing the position of the visible indicator. Optionally, the movement is continuous in that the change in the tank weight may be monitored by a change in indicator position.

For example, in one optional embodiment, the indicator is a band slidably received into the base. The movement of the band is coupled to, and parallel with, the movement of the spring. Thus, the band is received into the base, and thereby at least partially obscured from view by the base, when the spring is at a first deflection under a first tank weight when the tank holds a first volume of contents. Alternatively, the band is raised from inside the base by the spring, and thereby visible, when the spring is at a second deflection under a second tank weight less than the first tank weight when the tank holds a second volume of contents less than the first volume of contents. In other words, as the tank weight changes, the deflection of the spring changes thereby exposing a continuously increasing (or in an alternate embodiment, decreasing) portion of the band.

In another optional embodiment, the base includes a diagonal slot therethrough. As above, the indicator is a band slidably received into the base. In this optional embodiment, however, the band is visible through the slot. As the spring deflects under the tank weight, movement of the band causes the band to either appear increasingly or decreasingly visible through the slot or appear to move across the slot from a first position to a second position.

In yet another optional embodiment, the base includes a slot and the indicator is a pin protruding through the slot. Movement of the pin is coupled to the movement of the spring such that the pin moves between a first position and a second position in the slot when the spring deflected under the tank weight. Thus, the tank weight is indicated by the position of the pin in the slot.

In another optional embodiment, the spring is an leaf spring having two ends, a fixed first end and a second end. In such an embodiment, the indicator is a pivotable pointer, the pointer connected to the second end of the leaf spring such that movement of the pointer is coupled to the movement of the leaf spring. As the spring is deflected by the tank weight, the pointer pivots between a first position and a second position.

DESCRIPTION

Reference is now made to the figures wherein like parts are referred to by like numerals throughout. Referring generally toFIGS. 1–13the present invention is a support for a tank10that measures and indicates the volume of the contents of the tank10.

The tank10used in the present invention may be any tank10known in the art. The typical tank10is metal and includes a valve regulating the release of pressurized tank contents. For the purposes of this invention, the term “tank weight” as used herein refers to the weight of the tank10plus the weight of the tank contents.

The device of the present invention includes a base12. The base12is fixed in some fashion, such as, for example, by resting on a horizontal surface or by mounting it to a horizontal or vertical surface. For example, in one optional embodiment, shown inFIGS. 1–8, the base12rests on a horizontal surface such as the ground, a shelf, or the like. In such an optional embodiment, the base12is a ring. As shown inFIG. 8, the base12optionally cooperates with a tank cover18to enclose the tank10. Such a base12may also optionally include rollers20, such as wheels or casters. As shown inFIGS. 12 and 13, the rollers20may be retractable. In the optional embodiment ofFIGS. 12 and 13, a retracting handle22may actuate extension and retraction of the rollers20.

Alternatively, in an alternate embodiment, shown inFIGS. 9–11, the base12is mounted to a vertical surface such as a wall14, gas appliance or appliance support, or the like. In such an embodiment, the base12is a cantilevered surface such as an L-shaped or U-shaped bracket24.

Referring generally toFIGS. 1–11, a spring26is also provided. The spring26is deflectable with respect to the base12. The spring26may be a coil spring, a leaf spring28, or any other spring. The spring26supports at least a portion of the tank weight. Optionally, the spring26is positioned under the tank10and supports the entire tank weight. It should be noted that one or more springs26could be provided. For example, as shown inFIG. 5, four springs26are provided.

Referring toFIGS. 1–8, the spring26is a coil spring located vertically under a tank10. While the tank10could rest directly on the spring26, a cradle30is provided that receives and supports the tank10. The spring26is a compression spring biased to resist the weight of the tank10.

Turning toFIGS. 9–11, the spring is a leaf spring28mounted to the base12. The leaf spring28includes two ends, one of which is fixed. The arc of the leaf spring28is biased to resist, and thereby supports, the weight of the tank10.

Referring generally toFIGS. 1–11, the device further includes a visible indicator connected to the spring26. The visible indicator moves with the spring26as the spring26deflects with respect to the base12under the tank weight. That is, when the spring26is at a first deflection under a first tank weight when the tank10holds a first volume, the indicator is at a first position. Similarly, when the spring26is at a second deflection under a second tank weight less than the first tank weight when the tank10holds a second volume less than the first volume, the indicator is at a second position. That is, the indicator visibly illustrates the volume of the tank10based on deflection in the spring26caused by the weight of the tank10. Optionally, the movement of the indicator is continuous in that as the tank10increases or decreases in weight, the indicator moves to indicate the change.

More specifically, as shown inFIGS. 1 and 2, in one optional embodiment, the indicator is a band34coupled to the movement of the spring26. The band34moves parallel with the movement of the spring26and is slidably received into the base12. As illustrated inFIG. 1, when the tank10is empty, the spring26raises the band34from inside the base12so that the band34is visible. Alternatively, when the tank10is not empty as shown inFIG. 2, the spring26is deflected and the band34is received into the base12so that the band34is at least partially, if not fully, obscured by the base12from view. In other words, as the tank weight decreases from the state shown inFIG. 2to the state shown inFIG. 1, an increasing (or in an alternate embodiment, decreasing) amount of the band34is visible.

In yet another optional embodiment, shown inFIGS. 3–5, the indicator is again a band34. However, in this optional embodiment, as shown inFIG. 5, the base12includes a diagonal slot36through which the band34is visible. Again, movement of the band34is coupled to the deflection of the spring26. As above, an empty tank10, illustrated inFIG. 3is indicated by the band34being raised by the spring26to be visible though the slot36. Alternatively, as shown inFIG. 4, a tank10that is not empty deflects the spring26and thereby partially, if not fully, obscures the band34from view through the slot36. Thus, as the tank weight decreases, the deflection of the spring26decreases and movement of the band34into the base12causes the band34to either appear increasingly or decreasingly visible through the slot36or appear to move from a first position to a second position in the slot36.

In another optional embodiment, shown inFIGS. 6 and 7, the base12includes a slot36. However, in this embodiment, a pin38protrudes through the slot36. The pin38is coupled to movement of the spring26. The compression of the spring26, as well as the tendency of a coil spring to twist as the coils are compressed and expanded, causes the pin38to move within the slot36. Thus, as the tank weight decreases, the deflection of the spring26decreases thereby permitting the pin38to move from a first position, shown inFIG. 7, to a second position, shown inFIG. 6.

Turning toFIGS. 9–11, in yet another optional embodiment, the spring is a leaf spring28. As described above, the arc of the leaf spring28supports the tank weight. Optionally, the tank10is suspended from the arc of the leaf spring28. The leaf spring28has two ends, a first end that is fixed and a second end. The indicator is a pivotable pointer40connected to the second end such that movement of the pointer40is coupled to deflection in the leaf spring28. As the weight of the tank decreases, deflection of the leaf spring28decreases and the pointer40pivots from a first position, shown inFIG. 10, to a second position, shown inFIG. 11.

While certain embodiments of the present invention have been shown and described it is to be understood that the present invention is subject to many modifications and changes without departing from the spirit and scope of the claims presented herein.