1. Field of the Invention
The present invention is directed to blade tension gauges for band saws and the like.
2. Description of Related Art
In order to cut properly, the blade of a band saw must be pre-tensioned to an adequate degree so that the blade can more easily resist any twisting or sideways movement during cutting. Blades of different sizes require different loads to achieve this state. Loads that are too low do not provide adequate stiffness to the blade. Loads that are too high can cause blade breakage and premature failure. Current practice for many users is to adjust the blade tension “by ear”, that is to apply load until the tension “feels right” in terms of the sound the blade makes and the way it performs. Another practice is to physically push on the blade to deform the blade. The degree of deflection of the blade is used as an indication of the blade tension. Yet another practice is to install a spring in the blade tensioning mechanism. The degree of deflection of the spring as the blade is tensioned provides an indication of the load on the blade. Users simply apply load until the end of the spring lines up with the proper point on a scale marked on the saw. These methods are notoriously inaccurate and make it difficult to consistently set just the right tension for best performance and longest blade life.
Another practice currently in use by users who desire a more accurate reading of blade tension or strain is the use of a special mechanical gauge applied directly to the steel of the blade. Such gauges work by measuring the deflection of a specified length of a section of the blade. Such gauges do give fairly accurate results, but can only be used when the blade is stationary and cannot provide information about the tension in a blade as a band saw is actually running and cutting material. Since they are relatively expensive and somewhat cumbersome to use, many band saw users do not own such a device. Even those who have such a gauge seldom use it as often or diligently as they should to ensure proper operation of their saw.