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:
Sep. 04, 2007
Filed:
Feb. 04, 2004
Julius I. Pershwitz, Grantham, PA (US);
Thomas R. Berg, Warson Woods, MO (US);
Julius I. Pershwitz, Grantham, PA (US);
Thomas R. Berg, Warson Woods, MO (US);
ASF-Keystone, Inc., Granite City, IL (US);
Abstract
A tuned spring group with load springs, control springs, and a frictional damping arrangement for a railcar truck assembly provides better ride quality, increased resistance to suspension bottoming, and increased hunting threshold speed of a railroad car. Specifically, this tuned damping and suspension arrangement provides a spring group reserve capacity of less than 1.50. Spring assemblies for different car types are tuned such that a reserve ratio less than 1.50 may be achieved. By reducing the spring assembly reserve capacity for a railcar and truck of a standard weight and configuration to less than 1.50, an unexpected result of a decrease in maximum vertical acceleration as the railcar truck assembly approaches a speed of 55 miles per hour is achieved. The decrease in vertical acceleration allows for improved ride quality, increased resistance to suspension bottoming and increased hunting threshold speed of the railcar.