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:
Nov. 21, 1995
Filed:
Apr. 25, 1994
David A Lange, Bay City, MI (US);
Thomson Saginaw Ball Screw Company, Inc., Saginaw, MI (US);
Abstract
A ball nut and screw assembly has a backdrive control member that travels with the ball nut and has an internal thread complementary to and engaging the helical ball receiving groove on the screw. The backdrive control member is indexable on the screw relative to the ball nut to adjust the load of a spring that is interposed between the control member and ball nut. The spring acts to urge these components apart and thereby determine the frictional drag of the threaded engagement between the control member and the ball screw. The preload of the spring is set by indexing the control member to effect sufficient drag to prevent axial loads on the nut and screw from causing backdrive translation of the nut. The backdrive control member also removes lash from the ball nut and screw assembly under reversing loads at load magnitudes equal to or less than that produced by the load spring.