Protection valve device for spring parking brake systems
AssigneeGeneral Signal Corporation
InventorLawrence Vaughn
Life of this patent
Estimating the term…
Abstract
A protection valve device for a spring parking brake control system has a pipe bracket for connection in a normally pressurized brake pipe, the pipe bracket having connected thereto a protection valve, a charging reset valve and a charging check valve. The protection valve has a chamber at one side of a piston normally pressurized by pressure at a spring parking brake cylinder port and monitors the spring parking brake cylinder pressure to vent fluid from the brake pipe to automatically cause an emergency brake application if such pressure indicates a spring parking brake is applied. The charging reset valve prevents the venting of brake pipe fluid during charging of the brake pipe and spring parking brake system.
Claims16
A protection valve device for connection in a normally charged brake pipe comprising;
- (a) a brake pipe bracket for connection in a brake pipe having charging reset valve means connected thereto for governing venting of fluid from a vent brake pipe port of the pipe bracket,
- (b) protection valve means secured to the pipe bracket for governing the venting of fluid from a port of the charging reset valve means,
- (c) charging check valve means secured to the pipe bracket having a port for delivery of brake pipe fluid to the protection valve means,
- (d) the pipe bracket having passages and ports for connection of the brake pipe to the protection valve means and the charging check valve means respectively, and
- (e) the pipe bracket having passages for connection of the protection valve means and the charging check valve means to a spring parking brake cylinder port.
A protection valve comprising;
- (a) a piston for sensing pressure at a brake pipe port and at a spring parking brake port,
- (b) a protection graduating spring acting on one side of the piston,
- (c) spool charging valve means connected to the piston for initially supplying fluid pressure from a brake pipe when it is being charged to a protection chamber for acting on the piston in opposition to the protection graduating spring, the spool charging valve means being closed after initial movement of the piston as brake pipe pressure increases, and
- (d) bypassing passage means for bypassing the spool charging valve means for further pressurization of the protection valve chamber from the brake pipe to continue movement of the piston in opposition to the protection graduating spring as brake pipe pressure continues to increase until pressure in the chamber is substantially at normal brake pipe pressure.
Dependencies are inferred from the claim text.