Abstract: A plurality of boring cutters and honing stones are coaxially arranged on a machining head. A bar member is reciprocatingly inserted and splined within a rotary hollow spindle. Both the end opening surface of the spindle and the end of the bar member are taper-engaged with each other so that the bar member may be disengaged and moved forwardly with respect to the spindle. The machining head is coupled with the end surface of the bar member. When the spindle is taper-engaged with the bar member, a workpiece is bored. When the bar member is moved forwardly to release the taper engagement, the workpiece is honed by reciprocating the bar member and the machining head. Thus, the honing operation can be performed with a rigid structure, and both boring and honing operations can be effected by the same machining head.

Abstract: A honing head comprises a holder having a plurality of radial guide slots angularly spaced from each other and an axial hole, a rough-finishing cone shaft and a finishing cone shaft or a single cone shaft axially slidably received in the hole, and a plurality of rough-finishing and finishing honing stone supports alternately disposed in the guide slots for radial movement therein. The honing stone supports have axially spaced legs having inclined cam surfaces held in abutment with tapered portions of the cone shafts. The honing stone supports are connected to the cone shafts by connectors having one ends fixed to the honing stone supports and second ends slidably received in grooves defined in the cone shafts or the supports and having portions inclined with respect to the axes of the cone shafts in the same direction and at the same angle as the inclination of the tapered portions.