George W Ray

US Patent:

48561754, Aug 15, 1989

Filed:

May 18, 1988

Appl. No.:

7/195219

Inventors:

Eugene L. Swensen - Laurel MD
George F. Ray - Rockville MD

Assignee:

USG Interiors, Inc. - Chicago IL

International Classification:

B23P 1904

US Classification:

29460

Abstract:

An elevated floor panel is disclosed in which a lower sheet metal element is formed with a plurality of projections extending from the lower plane of the panel to the upper planar surface. The projections are formed in sequential die drawing operations. In the first die drawing operation, square truncated pyramids of intermediate height are drawn so that the upper surfaces of the intermediate projections provide substantially unworked material. In the second drawing operation, four symmetrically arranged, semispherical projections are drawn from the unworked material at the tops of the preliminary projections. In one embodiment, the tops of the semispherical projections are flattened. In another embodiment, the semispherical projections formed in the second drawing operation are fully curved. In such embodiment, a third operation is performed to produce a flattened extremity.