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:
Jun. 19, 1984
Filed:
Jun. 15, 1981
Edward J Falk, St. Louis, MO (US);
Echlin Inc., Branford, CT (US);
Abstract
The invention relates to an improvement in a valve for a tractor air brake system for changing the pressure delivered to air brakes on a tractor rear axle during 'bob tail' operation and particularly to a valve wherein the ratio is changed by communication of control pressure to a second control surface in accordance with the presence of trailer emergency pressure. The improved ratio control valve enables fluid pressure communication to both control surfaces of the ratio valve until a predetermined input pressure is reached so that the 'crack-open' input pressure for both the 'trailer-connected' and the 'bob tail' modes of operation will be the same. Further in accordance with the invention, a blend-back valve is provided which is biased by the available fluid pressure in the tractor reservoir tank so that the maximum available tractor reservoir pressure may always be applied to the tractor rear axle brakes even when the trailer is operating in the 'bob tail' mode.