초록 ▼

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 el

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.

대표청구항 ▼

[ That which is claimed is:] [1.]1. A railway car brake system comprising:at least one pneumatic brake cylinder;a relay valve for controlling pressure in the at least one brake cylinder responsive to a pilot pressure;at least one pilot valve connected to said relay valve for controlling the pilot pr

[ That which is claimed is:] [1.]1. A railway car brake system comprising:at least one pneumatic brake cylinder;a relay valve for controlling pressure in the at least one brake cylinder responsive to a pilot pressure;at least one pilot valve connected to said relay valve for controlling the pilot pressure, said at least one pilot valve comprising at least one piezoelectric element; anda controller connected to said at least one piezoelectric element for controlling the pilot pressure to thereby control braking.