Appliance for producing undercuts in holes in steps or other surfaces made of natural and/or ashlar stone

摘要

The invention relates to an appliance for producing undercuts in holes in steps or similar structural parts made of natural and/or ashlar stone, a threaded spindle being arranged perpendicularly on a stand and, at its lower end, carrying a laterally offset drive with an electric motor which is equipped with a holder for a grinding tool. According to the invention, which can be seen from Fig. 2 of the drawing, the drive housing (6) is split axially into two halves (6a, 6b), each of which is provided at the dividing lines with flange rims (7a, 7b), in the mutually facing surfaces of which congruent grooves are provided which, with the drive casing (6) assembled, form channels for the supply of cooling air to the drive (5) and extend obliquely in the dividing plane such that they form an acute angle with the tool-side part of the drive shaft (5a). The drive casing (6) accommodates a switch for the electric motor which can be operated by means of a switch pin (11) which penetrates the drive casing (6) tangentially and projects from the drive casing alternately with one of its two ends, depending on the switch position. IMAGE