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:
Mar. 15, 1994
Filed:
Apr. 14, 1993
Gary R Gillingham, Prior Lake, MN (US);
James C Rothman, Burnsville, MN (US);
Kelly C Robertson, Rosemount, MN (US);
Marty A Barris, Lakeville, MN (US);
Peter Betts, Prior Lake, MN (US);
Wayne M Wagner, Apple Valley, MN (US);
Donaldson Company, Inc., Minneapolis, MN (US);
Abstract
A muffler-filter apparatus having a particulate trap using filter tubes with high temperature filter materials, like fiber in the form of yarn, woven yarn mat, or a non-woven, random array fiber mat, or various foams. Filter tubes have various structural configurations and are regenerated by axial propagation using ring heaters or stub rod heaters, by heating the entire length of the filter tube with a rod heater or some other full-length heater configuration. For regeneration, exhaust flow is bypassed using various valve configurations including a poppet valve, a shutter valve, or a tubular valve. Filter tube filters may also be self-regenerated by the heat from the exhaust gases as controlled by a throttle valve or on inclusion of fuel additives which lower particulate ignition temperature.