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:
Feb. 16, 1993
Filed:
Sep. 30, 1991
Floyd R Emmons, West Hartford, CT (US);
United Technologies Corporation, Hartford, CT (US);
Abstract
The rate of change of cabin air pressure in an aircraft cabin during aircraft ascent and descent is controlled as a function of a ratio which is equal to (P.sub.ld -P.sub.c)/(P.sub.ld -P.sub.a) during descent, and is equal to (P.sub.cc -P.sub.c)/(P.sub.cr -P.sub.a) during ascent, where P.sub.ld is ambient pressure at the aircraft landing site, P.sub.c is cabin pressure, P.sub.a is external aircraft ambient pressure, P.sub.cc is cabin pressure at cruise altitude, and P.sub.cr is ambient pressure at cruise altitude. A set point value for the ratio is computed throughout aircraft ascent and descent, and compared to the ratio to schedule a variable flow area of an outflow valve in order to drive the difference (i.e., the error) between the ratio and the desired value for the ratio to zero. By using an adjustable value for the desired set point, control of cabin pressure rate of change is improved during ascent and descent, since the cabin pressure rate of change is maintained at a reduced, linear rate, thereby providing a more comfortable environment for passengers.