Abstract: A cylinder truing hone comprising a plurality of pressure members mounted in circumferentially spaced locations around a driven member for movement radially of the driven member and with pressure surfaces on the pressure members outermost. An axially movable cam on the driven member is in engagement with the pressure members and can move them outwardly. Abrasive coated sheet material extends over the pressure surfaces where it can be pressed into engagement with a cylindrical inner surface by movement of the cam, and a mechanism is provided for changing the portion of the abrasive coated sheet material extending over the pressure surfaces.

Abstract: A hub for a flap wheel assembly adapted to finish an arcuate convex surface. The hub has a central cross section around its axis with a circular periphery of a first diameter, opposite circular end cross sections axially spaced on opposite sides of the central cross section and having circular peripheries of second diameters substantially larger than the diameter of the central cross section, and a peripheral surface comprising a multiplicity of generally straight elongate surface segments extending between the peripheries of the end cross sections across and contacting the periphery of the central cross section with each segment crossing at a different radius of the central cross section from the axis of the hub and being disposed at the same angle with respect to the axis measured about the radius crossed by the surface segment.

Abstract: An abrasive flap wheel assembly including abrasive packets having their inner end portions disposed in recesses in the hub and being attached so that they project at about a right angle to a radius of the hub through the area of attachment between the hub and the abrasive packet to provide a small assembly that facilitates contact between a large portion of the major outer abrasive faces of the packets. Also the outer ends of the pieces of abrasive-coated material in the packets are spaced to provide exposed abrasive-coated end portions for the underlying pieces of abrasive-coated material in the packets.