Weighing scales – Preset – Spring support
Reexamination Certificate
1999-07-29
2001-09-04
Gibson, Randy W. (Department: 2859)
Weighing scales
Preset
Spring support
C177S171000, C177S203000, C177S235000, C177S256000, C177S260000, C073S001130
Reexamination Certificate
active
06284987
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to weighing scales, and is more particularly directed to a device for detecting and indicating changes in a small weight that is embedded within a much larger, i.e., heavier, residual weight.
It is difficult for the consumer to measure a small variable weight that is contained within a much larger weight, most of which is a relatively constant residual weight. It is also difficult to monitor and obtain an advance warning of the impending exhaustion of a given variable weight, which can be considered a critical weight.
A weight load can be considered to consist of two or more components, that is, an initial part, a critical part, and an end part. The critical part is typically significantly smaller than either of the other two components, but this is typically the component whose weight is of the most interest. Consequently, any weighing device that detects variations, i.e., gradual depletion, of the critical component should have a more sensitive scale for the critical part than for the other two parts. In many cases, the consumer needs to monitor only the critical part, and the weighing device or scale only needs to read and monitor the critical component, and not the initial or end parts.
A particular example of this is a cylinder of a consumable gas, such as propane or natural gas. The cylinder has an empty or residual weight which does not vary for that cylinder. Also, when completely filled with propane or natural gas, the cylinder has a full or initial weight, which also is a fixed value for that cylinder. The customer is interested in monitoring the weight of the cylinder so that he or she will be aware when the contents have been nearly consumed, and the cylinder is approaching an empty condition. Where the cylinder contains, for example, ten kilograms of propane, the consumer needs to know when it has emptied down to about the final one or two kilograms, which constitute the “critical weight.” Consequently, the weighing scale needs to monitor only for that range of zero to two kilograms, which lies somewhere between the cylinder's residual weight and the cylinder's full or initial weight. Thus, there is a need for a weighing device that monitors the critical part of the load.
There are many other applications as well, where the critical part of the load is embedded within the overall weight of the load, between the residual weight and the initial weight. There may also be a need to monitor the fill, rather than the depletion of a container's contents, in which case the critical weight would be increasing instead of decreasing. The critical weight range can be close to the initial weight instead of close to the residual weight.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a weighing and monitoring technique that avoid the drawbacks of the prior art.
It is another object to provide a weighing scale of simple design which accurately monitors the critical part of the weight load.
It is yet another object to provide a weighing scale that can be adjusted for its range and sensitivity in measuring changes within the critical weight range.
It is a further object to provide a weighing scale of rugged design and which can provide an audible and/or visible alarm.
In accordance with an aspect of the present invention, an embedded weight scale indicates variations in weight of an article wherein the variable weight is embedded within a heavier weight, and where the article has a base residual weight and a variable embedded weight. The scale has a base with first and second upstanding walls and a top pan adapted for supporting the article whose weight is to be monitored. There is a linkage, in this case formed of a pair of long levers and a pair of short levers. The long levers each have a first end pivotally supported on the first wall of the base and a second end, the second ends being joined together by a pivot pin or the like. The short levers each have a first end pivotally supported on the second wall of the base, and each has a second end that is pivotally joined to a midpoint of a respective one of the long levers. The top pan is supported at four points, i.e., at a respective position on each of the long levers and the short levers. There is a counterbalance pivot on said base, and this is preferably customer adjustable, i.e., by turning a wheel or screw. A counterbalance weight lever is joined at its first end to the second ends of said long levers, and this lever extends across the base, over the counterbalance pivot, to a second end. A counterbalance weight is supported on the second end of this counterbalance weight lever. The counterbalance weight lever has a range of movement that corresponds to the range of weight that includes the embedded weight, i.e., the critical weight, of the article.
An adjustable tensioning spring means permits the consumer to adjust the tension between the base and the long levers. Weight indicating means are also provided, including a sensor for sensing variation in the position of the counterbalance weight lever as it moves within its range, i.e., within the critical weight range of the embedded weight.
The weight indicating means may take the form of a potentiometer having a rotary slider, and a lever connecting the slider with the counterbalance weight lever. A gear multiplier or other means can be employed to increase the sensitivity range of the potentiometer.
The adjustable tensioning spring means can employ a spring holder plate affixed to said base, a spring tension adjusting screw on the spring holder plate, and a tensioning spring positioned between the spring holder plate and the second ends of the long levers.
The counterbalance weight may be selectively adjustable in its position on the counterbalance weight lever, so as to adjust the critical weight range. Also, there are stops provided to limit the movement of the counterweight lever, with the positions of the stops being selected to affect the selection of the critical weight range.
As can be understood, the range of counterbalance movement is governed by the height of the unit, and the positions of the stops, whereas the range of the critical weight is governed by the settings of the counterbalance weight, the counterbalance pivot, and the spring.
The above and many other objects, features, and advantages of this invention will become apparent to persons skilled in the art from the ensuing description of a preferred embodiment, which is to be read in conjunction with the accompanying Drawing.
REFERENCES:
patent: 3661222 (1972-05-01), Weickhardt
patent: 3693739 (1972-09-01), Kaloustian et al.
patent: 3773124 (1973-11-01), Bellivant
patent: 3788411 (1974-01-01), Oxley
patent: 3791467 (1974-02-01), Swersey et al.
patent: 3810638 (1974-05-01), Haack
patent: 3869009 (1975-03-01), Kuhnle
patent: 4084650 (1978-04-01), Terraillon
patent: 4319651 (1982-03-01), Robichaud
patent: 4382478 (1983-05-01), Hern
patent: 4399881 (1983-08-01), Theurer et al.
patent: 4524617 (1985-06-01), Krehel et al.
patent: 4715458 (1987-12-01), De Angelis et al.
patent: 4878356 (1989-11-01), Punches et al.
patent: 5031710 (1991-07-01), Parker et al.
patent: 5555764 (1996-09-01), Dybas
patent: 5721400 (1998-02-01), Haraldsson et al.
Japanese Patent Abstract—Title: Display Unit for Capacity of Vessel Such as Thermos; Application No. 54092296; Publication Date: Feb. 18, 1981.
Gibson Randy W.
Trapani Lawrence P.
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