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. 22, 2001
Filed:
Sep. 12, 1997
Douglas E. Breese, Northwood, OH (US);
Kellie L. Stevens, Holland, OH (US);
Christopher C. Cheney, Bowling Green, OH (US);
Spicer Driveshaft, Inc., Holland, OH (US);
Abstract
A noise reduction structure for an aluminum-based driveshaft tube includes a generally cylindrical member having a predetermined length. The noise reduction structure is disposed within a driveshaft tube in a press fit relationship with the inner surface of the tube. In general, the noise reduction structure is positioned within the driveshaft tube at a location where the amplitude of a standing wave caused by the reflection of the sound waves back and forth along the driveshaft tube is at its maximum value. The length of the noise reduction structure may be about 10% or less of the value of the length of the driveshaft tube. In a first embodiment, the noise reduction structure is formed from a polymeric foam material having a density of less than about 10 lb/ft,. Preferably, the material has a density in the range of about 2 lb/ft,to 10 lb/ft,, and more preferably, in the range of about 3 lb/ft,to 7 lb/ft,. One type of material which is particularly well suited for this invention is a polymeric cushioning foam having a density of about 5 lb/ft,. In a second embodiment, the noise reduction structure is formed from a plurality of relative long cylindrical members that are press fit within the driveshaft tube and are located equidistantly from one another. Each of these cylindrical members is preferably formed from a polyether material having density of at least 1.4 lb/ft,, and most desirably are formed having a density of 1.5 lb/ft,. In a third embodiment, the noise reduction structure is formed from a single elongated cylindrical member that is press fit within the driveshaft tube and is preferably formed from a polyether material having density of at least 1.4 lb/ft,, and more desirably is formed having a density of 1.5 lb/ft,. One or both of the end portions of the driveshaft tube may be formed having a reduced diameter.