Railway car braking system including piezoelectric pilot valve and associated methods
US6302495A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 4, 1999 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | Jun 4, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16K31/006
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A railway car brake system includes a pneumatic brake cylinder and a relay valve for controlling pressure in the brake cylinder. The relay valve is responsive to a pilot pressure which is generated by a pilot valve connected to the relay valve, the pilot valve including at least one piezoelectric element. The system also includes a controller connected to the piezoelectric element to control the pilot pressure and thereby control braking. The pilot valve releases braking upon loss of power to the at least one piezoelectric element to thereby provide a failsafe release of braking. The pilot valve may also include a first piezoelectric element for controlling fluid flow from a pressure source to the relay valve, and a second piezoelectric element for controlling fluid flow from the relay valve to atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.