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. 14, 1995
Filed:
Jul. 16, 1993
NGK Insulators, Ltd., , JP;
Abstract
A multi-stage honeycomb heater includes: at least two honeycomb heaters electrically connected with each other and disposed along a stream of fluid; the two honeycomb heaters including furthest upstream honeycomb heater and a an adjacent honeycomb heater which is adjacent to and downstream of the furthest upstream honeycomb heater; each of the two honeycomb heaters having an electrically conductive honeycomb structure the honeycomb structure of the upstream honeycomb heater having slits for adjusting its electrical resistance and/or element for adjusting heat capacity of the honeycomb structure so that the ratio of applied power to heat capacity of the furthest upstream honeycomb heater is larger than the ratio of applied power to heat capacity of the adjacent honeycomb heater. Thus the upstream heater and the downstream heater can give similar temperature increases without a temperature distribution along a flow direction during the engine warm-up. A catalyst composition is coated on the partition walls of the honeycomb structure, and the light-off temperature of the catalyst composition of the upstream honeycomb heater is lower than that of the adjacent honeycomb heater.