Freight brake control valve having an emergency piston slide valve and graduating valve arranged to provide an accelerated brake application function
US4744609A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 14, 1986 |
| Grant date | May 17, 1988 |
| Priority date | — |
| Expiry date | Nov 14, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T15/42
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A freight brake control valve device in which the emergency piston is arranged to operate a pair of slide valves having lost motion therebetween to provide a continuous, local reduction in the brake pipe pressure in response to initial actuation of the emergency piston when a service rate of brake pipe pressure reduction is made, in order to quickly propagate a brake pipe pressure reduction wave along the train and accordingly provide an accelerated application of the train brakes. This accelerated application function in response to a service rate of brake pipe pressure reduction is achieved during movement of the emergency piston toward emergency position, during which movement, the quick-action chamber "breathing" function also occurs, the latter being presently incorporated in the emergency piston slide valve to stabilize the emergency piston following initial actuation thereof, so as to prevent further actuation of the emergency piston to emergency position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.