Abstract: A height adjustment mechanism for varying the positioning of a rotating tool on a haft of a machine tool, such as a portable power tool, is in the form of a coupler between the blade and tool arbor. A head of the coupler accepts the tool and connects with a tool drive, the depth of the connection defining the working height or position of the tool. A pair of inter-engaged flanges are mounted upon the shaft of the coupler head, and apply forces to the coupler head and tool drive to maintain the connection depth therebetween and to retain the tool in position. A jam nut further maintains the relative orientation of the flanges.

Abstract: A blade-mounting adaptor for a power tool has a blade-mounting stud on which the blade is mounted at a first end. The blade is mounted upon the stud in a manner such that it is capable of axial motion along the length of the stud when exertion is applied to the blade. The blade is provided with an adjustable pre-set bias force against the axial motion.