The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 14, 1997
Filed:
Sep. 29, 1995
Harvey J Kallenberger, Wind Lake, WI (US);
Joseph L Huffman, Mukwonago, WI (US);
Harnischfeger Corporation, St. Francis, WI (US);
Abstract
Apparatus comprising a lower support structure having an upper surface, a circular lower rail which is mounted on the upper surface of the lower support structure and which is centered on a generally vertical axis, an upper structure having a lower surface, a circular upper rail which is mounted on the lower surface of the upper structure and which is centered on the axis, a plurality of rollers which are located between the upper and lower rails and which support the upper structure for rotation relative to the lower structure about the axis, the rollers being rotatable about respective generally horizontal axes intersecting the vertical axis at a common point, one of the rails including an inwardly facing surface defining a portion of a sphere centered on the point, and each of the rollers including an outwardly facing surface which engages the inwardly facing surface and which defines a portion of a sphere centered on the point.