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:
Jun. 11, 1991
Filed:
Aug. 22, 1989
James E Shaffer, Maitland, FL (US);
Consolier Industries, Inc., Riviera Beach, FL (US);
Abstract
A ball screw has a plurality of planar tracks of bearing balls arranged around the inner surface of the nut of a screw and nut machine. The shape of each track is designed to fit around a planar cross-section of the screw threads and each of the plurality of tracks is oriented at different angles with respect to the other tracks. A carrier is placed between the nut and screw and maintains the bearing balls separated from one another. In addition, each of the plurality of tracks are spaced at a fraction of the pitch of the screw thread pitch. By making each track planar, the bearing balls circulate within each track independently of the other tracks. In addition, a technique to design the shape of the track for a given thread shape includes determining the tangential point of each ball along the thread. The tracks may be divided into groups having a forward drive and reverse drive bias and the track may be made larger than the bearing balls to reduce wear at the thread peak.