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:
May. 18, 1999
Filed:
Sep. 04, 1997
Steven L Fletcher, Bristol, VA (US);
Thomas J Keller, Bristol, VA (US);
Dana Corporation, Toledo, OH (US);
Abstract
A method for applying a low friction coating to the cooperating splines of a slip joint that results in precise conformance between the intermeshing splines of the telescoping members includes the initial steps of cleaning, priming, and coating the splines of a tube shaft with a low friction material. Then, the coating on the splines is shaped to precisely conform to internal splines provided on a slip yoke of the slip joint. To accomplish this, an annular die is provided having a generally hollow and cylindrical shape, but tapering from a relatively large diameter upper end to a relatively small lower end. Thus, an inner frusto-conical surface is defined through the center of the die. A plurality of tapered splines is formed on the inner frusto-conical surface of the die that are generally shaped in a complementary fashion to the splines formed on the tube shaft. The die may be provided with a device for heating the die to a desired temperature. The splined end of the tube shaft is then lowered into the die such that the internal splines of the die engage the external splines of the tube shaft. Because the die is heated to a temperature above the melting point of the low friction material coating, the coating on the splines melts and conforms to the profile of the splines of the die. The movement of the tube shaft is continued such that the splines pass completely through the die and are then received in splined end of the slip yoke, which is also aligned with the tube shaft and the die. The tube shaft is then allowed to remain in the slip yoke for a period of time sufficient to allow the coating on the splines to cool and harden in precise conformance with the splines of the slip yoke. Lastly, the tube shaft is retracted from the slip yoke and the die. Alternatively, the die may be raised over the tube shaft, leaving the tube shaft inserted within the slip yoke for shipment and installation.