US 4,586,756 A · Brake control valve system for rail vehicle air brake

Abstract

Brake control valve system for rail vehicle air brake, comprising an emergency brake piston (7) having a first piston chamber (9) loaded by the quick action chamber with a much greater volume than its second piston chamber (8) loaded by the brake line. The effective pressure surfaces of the service brake piston and emergency brake piston are substantially identical. The emergency brake piston controls a first quick action exhaust valve (15) for venting smaller amounts of quick action air per unit of time, as well as a valve device (14) containing a second quick action exhaust for venting larger amounts of quick action air. Valve device (14) is pneumatically connected to the control piston (19) of a high pressure/emergency exhaust valve system (16) which operates only upon emergency braking. Piston (19) contains a nozzle (22) through which pressure remaining in the quick action chamber (10) during emergency braking is evacuated in a predetermined time. Piston (19) controls a high pressure seated valve (17) for connecting an emergency air container (3) to the brake cylinder during emergency braking, and a brake line emergency exhaust seated valve (18) providing large cross-sectioned connection of the brake line to atmosphere during emergency braking.

Brake control valve system for an indirectly operating air rake for rail vehicles, comprising:

(a) a service brake unit (SP);
(b) an emergency brake unit (EP);
(c) a service brake piston (4) forming part of said service brake unit (SP) and having first and second piston chambers (5, 6) located on opposite sides of said service brake piston (4), the first (5) of said chambers being connected to a brake line, and the second (6) of said chambers being connected to an auxiliary air container (2);
(d) an emergency brake piston (7) forming part of said emergency brake unit (EP) for controlling emergency braking, and having first and second piston chambers (8, 9) located on opposite sides of said emergency brake piston (7), the first (8) of said piston chambers being connected to said brake line, and the second (9) of said piston chambers being connected to a control chamber (10) and being switched to said brake line via a filling nozzle (11), said second piston chamber (9) having a volume several times as great as the volume of said first piston chamber (8);
(e) a high pressure/exhaust valve system (16) comprising a control piston (19) for (i) controlling a high pressure valve (17) which connects an emergency air container (3) to a brake cylinder (1) during emergency braking, and (ii) for controlling a brake line emergency exhaust valve (18) which switches said brake line to a vent of large cross-section during emergency braking;
(f) a first channel (26) continuously connecting a first control piston chamber (20) on one side of said control piston (19) to said control chamber (10);
(g) a second channel (27) connecting a second control piston chamber (21) on the other side of said control piston (19) to a valve chamber (28);
(h) a control chamber connecting/exhaust valve system (14) surrounding said valve chamber (28) and comprising
(i) coaxial first and second valve seats (29, 30) forming part of said valve chamber (28) and a common valve closure element (31) within said valve chamber for forming a control chamber connecting valve (29, 31) from said first valve seat (29) at the end of a third channel (29' and said valve closure element (31), said third channel (29') comprising a bore connecting said second piston chamber (9) to said valve chamber (28) through said first valve seat (29), and
(ii) a control chamber exhaust valve (30, 31) from said second valve seat (30) at the end of a fourth channel (43) and said valve closure element (31) with a control chamber exhaust nozzle (12) switched into said fourth channel;
(i) a first mechanical coupling device (33) between said valve closure element (31) and said emergency brake piston (7);
(j) a pulsating brake accelerator (23) operating at every stage of service braking and connected to said control chamber (10) by a brake accelerator inlet nozzle (13) within a fifth channel (51);
(k) a brake accelerator inlet valve device (15) between said control chamber (10) and said brake accelerator inlet nozzle (13);
(l) a second mechanical coupling device (48, 47) between said brake accelerator inlet valve device (15) and a first dead lift device switched into said first coupling device (33) for assuring that said brake accelerator inlet valve device (15) is switched to open position by said emergency brake piston before said control chamber exhaust valve (30, 31) and to closed position after said valve;
(m) the first dead lift device having a push rod (32) which reaches through said bore (29') and said first valve seat (29), said push rod being supported against said valve closure element (31), which is biased by spring means (34) into opening direction of said control chamber exhaust valve (30, 31).

12 more elements

Brake control valve system for rail vehicle air brake

Life of this patent

Brake control valve system for rail vehicle air brake

Life of this patent

Abstract

Claims14