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:
Aug. 04, 1998
Filed:
Jan. 28, 1997
James A Wood, Spartanburg, SC (US);
Richard J Mazur, Greer, SC (US);
Westinghouse Air Brake Company, Wilmerding, PA (US);
Abstract
A universal unit controls the brakes of a truck of a rail vehicle. The unit includes a service valve, an emergency valve, a variable load relay valve, a release valve, a local control device, a solenoid driver device and a brake assurance device. The service valve when opened provides a first control pressure. The emergency valve when opened provides a second control pressure. In response the control pressures, the variable valve provides to the brake cylinder a load compensated pressure proportional to air spring pressure. The brakes then apply to the wheels of the truck a force that accounts for the load borne by the rail vehicle. The release valve when opened prevents the variable valve from providing the load compensated pressure. The local control device controls the control pressures according to a brake force command signal and a control pressure feedback signal. The solenoid device operates the valves in response to valve command signals received from the local control device. The brake assurance device operates in a standby mode in which the local control device controls the release and emergency valves via the solenoid device or in an intervention mode in which it does not thereby assuring that the release and emergency valves open. This enables the variable valve to provide the brake cylinder with the load compensated pressure and therefore apply the brakes. The brake assurance device assumes the intervention mode in response to a loss of power or to a predetermined set of conditions.