Patent GB-1141338-A (GB)
Title: Improvements in and relating to brake control systems for multiple unit trains
Inventor: HOWARD JAMES YOUNG
IPC: B60T15/16
Filed: 1967-06-12
Abstract: 1,141,338. Fluid-pressure brakes. GENERAL SIGNAL CORP. 12 June, 1967 [1 July, 1966], No. 27041/67. Heading F2F. In a brake control system for a train of railway cars having a main locomotive 10 at the head of the train and helper locomotive 11 at an intermediate point in the train, the main locomotive has a brake control apparatus and a train brake pipe extending substantially throughout the entire length of the train of cars for controlling the application of brakes on the respective cars of the train, additional communication means also governed by the brake control apparatus on the main locomotive for communicating a brake signal to the helper locomotive, and electrically-operated sectionalizing valve SEC controlled by the brake signal communicated from the main locomotive for sectionalizing the train brake pipe at the location of the helper locomotive 11 into forward and rear sections and means effective when the train brake pipe is sectionalized for controlling the rear section of the train brake pipe by brake signals received at the helper locomotive from the main locomotive. Normal conditions.-In the diagrammatic representation shown in Fig. 2, the main locomotive 10 has a radio communication apparatus including an antenna 13 for communicating brake control signals to the helper locomotive 11 via a receiving antenna 14. The main locomotive is provided with a manual brake control logic 15 for controlling the air pressure in the train brake pipe 12 and brake control codes are selected and applied over a line 17 to a suitable modulator 18 which converts these codes into signals for transmission by the locomotive transmitter 19 to a suitable helper locomotive receiver 20 on the helper locomotive. These signals are demodulated by a demodulator 21 and applied to automatic brake control logic 22 for the control of the sectionalizing of the brake control pipe-line to control the degree of braking for the section of the pipe-line at the rear of the helper locomotive to correspond with the degree of braking that is being applied to the main locomotive in operation, the reception of a signal at the helper locomotive causes the automatic brake control logic 22 to provide an output via line 23 to energize the sectionalizing valve SEC to close the latter in the pipe-line 12 to sectionalize the pipe-line into a forward section 12a and a rear section 12b to be controlled by the main and helper locomotives respectively. When the valve SEC becomes deenergized the valve opens and the brake pipe 12 becomes de-sectionalized to permit the control of the brakes of the entire train from the main locomotive only. When the brake control line is sectionalized the automatic brake control logic 22 is effective over the line 24 to control the air pressure in the rear section of the brake line 12 in accordance with the brake control code that is communicated from the main locomotive. Emergency conditions.-Under certain emergency conditions, the automatic brake control logic 22 can be effective to reduce pressure in the forward section 12a of the brake control line 12, as represented by the line 25, to cause application of the brakes of the cars in the forward section in accordance with an emergency condition. A forward pressure switch FP is provided in the forward brake line 12a to enable detection of a reduction in brake pressure corresponding to an emergency condition in the forward section 12a of the brake control line 12. A similar pressure switch RP is provided in the rear brake line section 12b. So long as the communication link between the main locomotive and the helper locomotive is intact the sectionalizing valve SEC is closed and the main locomotive and the helper locomotive may contain corresponding air pressures in the respective forward rear section 12a and 12b. If the brakes are applied by the main locomotive, a code characteristic of the application is converted into signals and are transmitted by radio to the helper locomotive and the reception of these signals causes the automatic brake control logic 22 to select corresponding degree of braking to be applied by the helper locomotive to the section of the train in the rear of that locomotive over the brake control section 12b. Should the line of communication between the main locomotive and the helper locomotive be broken, the sectionalizing valve SEC becomes opened because of loss of energy in its control circuit over line 23 so that the system reverts to an unsectionalized condition of the brake line 12, but in the main locomotive has control of the entire train. Broken train pipe condition.-Should the forward section 12a lose its air pressure due to a broken line the loss of pressure is sensed by the pressure switch FP to cause the automatic brake control logic 22 to correspondingly reduce the pressure in the rear section 12b over the line 24. Similarly, if the rear section 12b is broken this condition is sensed by the pressure switch RP and the operation of this switch causes the automatic brake control logic 22 to correspondingly reduce the pressure in the forward section 12a over the line 25. Thus, a brake in the train either ahead of or in the rear of the helper locomotive 11 will cause the application of brakes of the entire train through the control of the automatic brake control logic 22 at the location of the helper locomotive without requiring any control on the part of the operator or the main locomotive. Instead of providing a radio communication system as shown, the system could include low frequency inductive systems as well as higher frequency wired radio where the transmitter transmits the brake signals and they are conductively communicated via wayside conductive materials to the rear of the train where they are inductively coupled to the receiver on the helper locomotive.