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Unformatted text preview: Only fives classes of features are distinguished, integral, smoothed, substitute, limited and nominal. In particular for the nominal features, all the seven classes of elements are considered (TTRS classes). GeoSpelling offers to the user the possibility to distinguish clearly the geometric elements manipulated during tolerance specification, tolerance inspection and tolerance analysis activities. The next important point of GeoSpelling is to provide univocal expressions of tolerances on geometry thanks to the characteristic concept. A characteristic represents a linear or angular quantity. Taken into account directly in the expression of the specification, the meaning, based on a mathematical expression, is unique and clearly described for everyone. There is no more interpretation for the designer, the manufacturer and the metrologist. Only five classes of characteristics are useful to express all the parameters needed through the tolerancing process. The characteristics exist, on a feature or between features on a part, or, between features on two different parts. They permit to express geometric requirements on an assembly. They permit also to express constraints between features. They support finally a statistical approach for tolerancing because they are only based on measurable quantities. In summary, GeoSpelling for th...
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- Spring '10
- The Land