Michael Thomas Burr

US Patent:

50957279, Mar 17, 1992

Filed:

Jan 19, 1990

Appl. No.:

7/469777

Inventors:

William J. Westerman - Columbia SC
Michael C. Burr - Lugoff SC
Farin L. Derrick - Columbia SC

Assignee:

Cogsdill Tool Products, Inc. - Camden SC

International Classification:

B21D 3910

US Classification:

72122

Abstract:

A roller burnishing tool is disclosed having inner and outer pluralities of concentrically disposed, precision tapered rolls. A precision tapered annular mandrel is disposed within the inner plurality of rolls and operates to controllably urge the inner plurality of rolls outwardly against a lip of a workpiece inserted between the inner and outer pluralities of rolls. The inner plurality of rolls forces the lip outwardly into contact with the outer rolls, and the pressurized contact of the rolls effects a burnishing action on the surfaces of the lip of the workpiece. In a preferred embodiment, the burnishing tool also includes a pilot stop for receiving an alignment post used to align the workpiece with the burnishing tool. When the burnishing tool engages the alignment post, the pilot assembly and mandrel are forced inwardly, whereby the tapered mandrel causes the inner rolls to be forced outwardly against an inner surface of the workpiece, thereby forcing the portion of the workpiece being machined outwardly against the outer rolls. The pressurized contact of the rolls effects a burnishing action which helps provide a micro surface finish to the surfaces of the workpiece.