Full Title

Single-purpose machines or devices for particular grinding operations not covered by any other main group (tapering, chamfering, or relief cutting of taps or reamers B24B3/20, B24B3/22, grinding screw threads B23G) > for grinding non-circular cross-sections, e.g. shafts of elliptical or polygonal cross-section > for grinding trochoidal surfaces, e.g. in rotor housings of Wankel engines