Abstract: A method for finishing a valve seat for ball valves, in particular for fuel injection valves in internal combustion engines. The workpiece to be finished and a finishing tool are driven in an opposite direction of rotation, whereby the axes of rotation of the workpiece and the finishing tool are aligned with each other at an angle of from 1°to 10°. The finishing tool rests against the inside surface of the workpiece to be finished over its entire circumference. The surface of the workpiece to be treated is provided with a crowned shape. A finishing stone with a wear-resistant and preferably cone-shaped working surface is employed as the finishing tool, whereby a narrow sealing zone with a convex contour in the longitudinal section is produced in the crowned surface of the workpiece by partial removal of material.

Abstract: An outer surface of a cam on a camshaft extending along a camshaft axis is honed by continuously rotating the camshaft about its axis while holding a grinding stone adjacent the cam with a surface of the stone directed radially inward at the cam surface. Movement of the grinding stone is restricted to displacement in two directions, one direction extending substantially radially of the camshaft axis and the other direction extending generally perpendicular to the one direction. The grinding stone is urged in the one direction extending radially of the axis against the stone to press the cam surface radially inward against the cam surface for contact of the stone surface along a line with the cam surface so that the stone moves in a radial direction as the camshaft rotates. The stone surface is continuously reciprocated in the other direction generally parallel to a plane perpendicular to the radial direction so as to continuously move the contact line between the cam and stone surfaces.

Abstract: An outer surface of a cam on a camshaft extending along a camshaft axis is honed by continuously rotating the camshaft about its axis, holding a grinding stone adjacent the cam with a surface of the stone directed radially inward at the cam surface, urging the grinding stone radially of the axis against the stone and thereby pressing the cam surface radially inward against the cam surface for contact of the stone surface along a line with the cam surface, and continuously displacing the stone surface in a direction generally tangential of the camshaft axis and thereby continuously moving the contact line between the cam and stone surfaces. Thus the contact line between the stone and the cam will move continuously, so that wear will not be concentrated in one location and the stone will not wear to fit in surface contact on the cam. The cam surface includes a part-cylindrical base region coaxial with the camshaft and a lobe region projecting radially outward from and joined to the base region.

Abstract: An apparatus for grinding a metallic workpiece rotating about and centered on an axis and having an annular surface also centered on the workpiece axis has a tool support radially offset from the workpiece axis, continuously rotating about a support axis radially offset from and substantially parallel to the workpiece axis, and having an forwardly axially directed front support face, and an annular grinding tool engaging the workpiece surface, centered on a respective tool axis, and having an axially backwardly directed rear tool face. The tool face is resiliently supported on the support face annularly all around the support and tool axes so that the tool axis can rock relative to the support axis.

Abstract: A grinding apparatus has a tool support radially offset from a workpiece axis, rotatable about a support axis radially offset from and substantially parallel to the workpiece axis, and having a forwardly axially directed front support face formed at the support axis with an axially forwardly projecting centering formation formed a forwardly convex and part-spherical end surface. An annular grinding tool centered on a tool axis has an annular axially forwardly directed grinding surface engaging the workpiece surface and an axially backwardly directed rear tool face axially confronting the front support face and formed centered on the tool axis with an axially backwardly open recess engaging the end surface of the projection and of part-spherical shape complementary to the projection end surface. This tool is spaced from and out of direct contact with the support except at the recess and projection end surface.

Abstract: The grinder, especially a high precision grinder, for a ring bearing which has a race with a curved cross section comprises at least one tool support and at least one tool holder. The tool holder is support in the tool support on two equal feed guide rods. A feed piston cylinder device for a feed and a withdrawal motion is provided. The tool support with the tool holder is oscillatable to and fro about a substantially central oscillation axis through the tool support which provides a tool mounted in the tool holder in the working position with a to and fro pivoting motion rotating substantially about the center of the curved cross section of the race. To minimize disturbing vibration the feed guide rods are held and secured at both ends by at least one crosstie bar. The crosstie bars at both ends of the feed guide bars are mass balanced in regard to the pivoting motion.

Abstract: A honing, superfinishing or superfinished grinding system utilizes a tool rotatable about an axis for superfinishing a surface of a thin wall workpiece whose other surface is directly contacted by a coolant to remove heat directly opposite the machining surface and thereby prevent distortion.

Abstract: A rough-ground camshaft has a shaft extending along and defining an axis and carrying a plurality of axially spaced cams each having a cam surface. This camshaft is finish-ground in system wherein for each cam there is a respective coarse prefinish tool and a respective fine finish tool. Every other cam surface is engaged in one diametrial direction by the respective coarse prefinish tool and in the opposite diametrical direction by the respective fine finish tool, and vice versa for the remaining cams, so that the prefinish tools, like the finish tools, alternate to opposite side of the camshaft axis. The camshaft is rotated about its axis and to start with all of the tools are urged against the respective cams, so that each cam is engaged in one diametrical direction by the respective prefinish tool and in the opposite direction by the respective fine finish tool. This shapes the tools, whereupon the fine finish tools are retracted for prefinishing of the cam surfaces.