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:
May. 02, 1989
Filed:
May. 20, 1988
Robert A Biegel, Riverdale, IL (US);
Thrall Car Manufacturing Company, Chicago Heights, IL (US);
Abstract
A railroad freight car comprising a freight-carrying first elongated body supported at one end by a first truck and at the other end by a second truck; each truck having a plurality of wheels and carrying air pressure operated braking apparatus for braking the wheels; the air pressure operated braking apparatus on the first truck including a pressurized air line having an air pressure sensor/changeover valve which governs the braking pressure applied only to the wheels of the first truck; the first truck having a bolster, spring-supported at each end by wheel-containing side frames, whereby the bolster is lowered relative to the frame when the elongated body condition varies from empty to loaded; a base mounting the air pressure sensor/changeover valve to the bolster; and, the valve having an arm responsive to change in height of the bolster relative to the frame to decrease the air pressure to the brake apparatus from a high pressure, when the elongated body is loaded, to a lower pressure when the elongated body has an empty load condition to thereby apply a predetermined high braking force to the wheels when the elongated body is loaded and apply a decreased or lower braking force to the wheels when an empty condition exists.