One man hand saw for cutting cellular building block - has teeth whose pitch increases progressively from leading blade tip inward

摘要

The Special purpose one man hand saw is used to cut cellular concrete building blocks on site. The blade has a progressively reducing tooth pitch. The teeth at close centres are used to start a cut and those at greater centres to effect the cut proper. The tool, thus, combines starting precision with cutting efficiency. The pitch may be increased progressively from the free blade end to the inboard end with integral handle. Identical cutting bits may be set into each tooth and the pitch may be 1:3 i.e. x1 may be 11 mm and x2 may be 33 mm.