GB803565A - Composite vacuum and compressed fluid railway braking equipment - Google Patents

Abstract

803,565. Fluid pressure brakes. WESTING- HOUSE AIR BRAKE CO. July 18, 1956 [July 19, 1955], No. 22221/56. Class 103 (1). In a composite railway braking equipment having a compressed fluid braking system operative to cause a brake application on reduc. tion of the pressure of compressed fluid in a brake pipe 3, and a vacuum braking system operative to cause a brake application on reduction of the vacuum in a train pipe 2, the arrangement is such that operation of the compressed fluid braking system effects, automatically, operation of the vacuum braking system to a corresponding degree, the equipment including an application valve device 5, which is responsive to reduction of the pressure of compressed fluid normally maintained in a control chamber thereof, to initiate a reduction in pressure in the brake pipe 3; a protection valve device 8 being so adapted that in response to reduction of train pipe vacuum acting therein, it opens the control chamber of the application valve device 5 to atmosphere through port 99 and thereby causes the aforesaid reduction of pressure therein. A suppression valve device 7, interposed between the application valve device 5 and the protection valve device 8 closes communication therebetween of a predetermined pressure, such as 50 pounds per square inch, supplied to brake cylinder 120 is operative in chamber 54. Such action also prevents a diaphragm foot valve 6 from causing the application valve device 5 to reduce the brake pipe pressure if the pedal 51 is left undepressed by the driver's foot. The vacuum control device 1 operates to reduce the vacuum in the train pipe 2 in correspondence with the reduction in pressure in the compressed air pipe 3. The equipment is intended primarily for shunting locomotives, which may be used to haul vehicles equipped with either vacuum or compressed fluid brakes.