GB875336A - Electro-pneumatic braking arrangement for rail vehicles - Google Patents

Abstract

875,336. Electro-pneumatic brakes. KNORRBREMSE G.m.b.H. Nov. 19, 1959 [Dec. 4, 1958], No. 39292/59. Class 103 (1). A braking arrangement for rail vehicles comprises the combination of electro-pneumatic means which can electrically control the braking and release-stages of the braking arrangement, with a strictly compressed air brake equipped with a train pipe 21 and triple pressure control valve 27, in which the train pipe 21 is arranged to be maintained at a regulation pressure level when the braking is controlled electrically, while the triple pressure control valve 27 is shut off by an electropneumatic valve from the train pipe, wherein supervisory means 31, 73 are provided which lower the train pipe pressure on failure of the electro-pneumatic means and connect the triple pressure control valve to the train pipe when the pressure in the latter reaches a reduced value corresponding to the braking stage of the initially electrically controlled braking. The driven brake valve 7 operates through a relay valve 3 to control the pressure in train pipe 21 from which a branch leads by way of a non-return valve 23 to a compressed-air reservoir 25 and a triple pressure control valve 27. An additional branch line connects the pipe 21 to the valve chamber 29 of an operating valve 31 having a valve member 33 bearing on one arm of a rocking lever 35, the other end of which co-operates with an abutment 74 on the draw bar 73 of a graduating valve 77. By means of handle 107 connected with the brake valve 7, a variable resistance 109 of an electrical brake control means is operated and a switch 111 are so coupled that in the " go " position of the handle 107, the full resistance of the variable resistance 109 is in circuit and the switch 111 is opened, while in the braking positions, with increasing brake force, the resistance 109 is progressively reduced and the switch 111 is permanently closed. A line leads from the variable resistance 109 to a variable compensating resistance 117 and on to the electrical actuating device 69 which is connected in series with any desired number of additional actuating devices 69<SP>1</SP>, which are distributed on the individual waggons of a train. The coil of a relay 121 at the rear end of the train is connected in a return line 119 leading from the last actuating device 69<SP>1</SP> to the other terminal of current source 115. Thus the driven valve 7 controls, through relay valve 3, an operating valve 31 on the one hand, and variable resistance 109 and actuating device 69 on the other hand, the movement of the rocky lever 35 which through graduating valve 77 and pipe 97 govern the triple pressure control valve 27. In one modification described the current source 115 is connected by way of a connector 13 (see Fig. 2, not shown) to the primary winding of a regulating transformer from the secondary winding of which any desired voltage can be tapped. In a second modification, the electrical actuating devices 69 are connected in parallel.