Abstract: An apparatus for microfinishing an interior cylindrical surface. The apparatus includes a mechanism which holds and rotates the workpiece about an axis. A tool, having radially directed work areas, is positioned within the workpiece and causes a strip of abrasive sheet material, positioned over the work areas, to engage the rotating workpiece. With the abrasive sheet material engaging the rotating workpiece, the tool is axially oscillated.

Abstract: An apparatus for micro-finishing a brake drum braking surface. The invention uses a center of rotation gaged from the unfinished braking surface to properly position the brake drum on the apparatus and position a shoe for engagement with the braking surface A film, having an abrasive surface, is routed over the shoe so that the abrasive surface will contact the braking surface. The brake drum is rotated and the film is urged into contact with the braking surface while the film and the shoe are axially oscillated along the rotational axis of the brake drum. In mounting the brake drum on the micro-finishing apparatus, a mechanism is provided for simulating the mounting forces normally incurred by the brake drum during use.

Abstract: An improved micro-finishing machine is disclosed in which a transfer system is provided to move workpieces into and out of the machine in a path perpendicular to the axes of the machine drive rollers. The transfer system further enables an inprocess size control gauge to be added to the machine to monitor the diameter of the workpieces during micro-finishing. The machine offers greater flexibility by enabling the machine to be easily reconfigured to micro-finish other parts. The transfer system utilizes ejectors that are simple in construction, requiring a minimal number of components.

Abstract: A microfinishing apparatus and method is disclosed particularly useful for microfinishing workpiece surfaces such as are found in journal bearings and cylinder bores. This invention improves over conventional machines and methods wherein coated abrasive tape is brought into contact with a relatively rotating workpiece surface and is pressed against that surface by an elastomeric plastic insert. According to this invention, the insert is made from a relatively rigid substance such as honing material stone. Since the insert is made from a rigid material, the insert surface shape is generated in the workpiece surface and therefore geometry corrections in the workpiece surface can be accomplished. In alternate embodiments of this invention, the rigid inserts have relieved portions or noncylindrical surfaces such that a desired surface profile in the workpiece surface is generated. In another embodiment, one or more flexible inserts are added to the rigid insert enabling the fillet radius area to be microfinished.