Abstract: The rotary workhead device, which is loaded on the table of a machine tool and onto which a workpiece to be machined is rotatably mounted, is equipped with: a base plate that is attached to the table of the machine tool; two rotary workheads that are provided on the base plate and disposed so that the axes of rotation coincide and the workpiece-fixing parts face each other; a guide means that is provided so as to be capable of moving at least one of the rotary workheads back and forth in the direction of the rotation axes; and an impelling means for impelling the one rotary workhead in a direction that separates or brings together the two rotary workheads. The rotary workhead device applies a tensile force or a compressive force on a workpiece, the respective ends of which are fixed between the two rotary workheads.

Abstract: A grinding method includes the steps of holding a workpiece by a pair of centering members of a pair of spindle equipment, shifting two centering members to one side of a spindle rotational axis, facing a grinding wheel at the other side to the other end portion of the workpiece, grinding the other end portion of the workpiece by the grinding wheel at the other side by rotating a driving pin of the spindle equipment at one side, retracting the grinding wheel at other side and stopping the rotation of the driving pin at one side and also shifting two centering members to the other side of the spindle rotational axis, facing a grinding wheel at one side to one end portion of the workpiece, and grinding one end portion of the workpiece by the grinding wheel at one side by rotating a driving pin of the spindle equipment at the other side.

Abstract: For the machining of a workpiece (18) rotating about a workpiece axis, a first abrasive tool (20), which rotates about a first tool axis, and the workpiece (18) are advanced towards one another, in order to machine a first workpiece face in a first abrasive operation. Further, a second abrasive tool (54), which rotates about a second tool axis (56), is advanced towards the workpiece (18), in order to machine a second workpiece face in a second abrasive operation. The two workpiece faces are designed rotationally symmetrically with respect to the workpiece axis and are arranged adjacently to one another in such a way that a sharp, burr-free, circular transition edge is formed between them. The two abrasive operations are controlled in such a way that they are terminated at the same time.

Abstract: A method and apparatus for a circular grinding of a workpiece having first and second workpiece faces which are rotationally symmetrical with respect to the workpiece axis and which form a circular transition edge between them are provided. The workpiece rotating about its axis and a grinding wheel rotating about a grinding-wheel axis are advanced towards one another. During grinding, an auxiliary abrasive tool, which rotates about an auxiliary-tool axis and has a plane abrasive surface arranged at right angles to the auxiliary-tool axis, is pressed against the workpiece in such a way that the abrasive surface is arranged in a tangential plane to the second workpiece face and touches the second workpiece face along a contact line. The plane abrasive surface projects in the direction of the contact line away from the second workpiece face beyond the transition edge.

Abstract: A blade sharpener comprises a work surface consisting of a single support line. A grinding wheel defines a plane that contains the support line. The grinding wheel is swingable in the grinding wheel plane to a selected position relative to the support line. A blade is supported on the support line in a manner that produces a first cutting surface on the blade cutting edge. The single support line enables mulching blades to be sharpened without having to impart angular motions in space to them as they are fed past the grinding wheel. The grinding wheel is swingable to different positions relative to the support line, thereby enabling the grinding wheel to produce different cutting surfaces on the blades. Swinging of the grinding wheel is achieved by mounting it to a plate that pivots about an axis perpendicular to the grinding wheel plane. A mobile work table having a top plate of finite area is selectively retainable over and removable from the single line support.