Abstract:
A control system which allows electro-pneumatic control of an equalizing reservoir with the capacity to create penalty applications in a purely pneumatic manner. A controller for the equalizing reservoir includes an electro-pneumatic source of pressure or atmosphere responsive to an electrical equalizing pressure control signal and a pilot valve selectively connecting the electro-pneumatic source or atmosphere to the equalizing reservoir in response to pressure in a pilot port of the first pilot valve. A magnetic valve is provided having a first input connected to a second source of pressure, a second input connected to atmosphere and an output connected to the pilot port of the first pilot valve. At least one penalty valve is connected to the pilot input of the first pilot valve and is responsive to a penalty signal to connect the pilot input to atmosphere. The pilot valve and the penalty valve pneumatically produce a brake application regardless of the state of the magnetic valve or its controller.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present system relates generally to brake control systems and more specifically to a controller for an equalizing reservoir of a rail brake system, which includes a brake pipe controlled by a relay valve in response to pressure in the equalizing reservoir. 
     Prior rail brake systems have had either fully-pneumatic control of the equalizing reservoir (ER) or electro-pneumatic control of the ER. On systems which use fully-pneumatic ER control, penalty brake applications were created by exhausting a previously pressurized penalty pipe. This caused a subsequent pneumatic exhaust of the ER and brake application. On systems which use electro-pneumatic ER control, penalty brake applications are signaled to the brake system by electrical signals. The ER is then reduced to apply the brakes via electro-pneumatic control. Prior brake systems including ER controllers are illustrated in U.S. Pat. Nos. 6,036,284 and 6,318,811. 
     The present control system allows electro-pneumatic control of ER but with the capacity to create penalty applications in a purely pneumatic manner. A controller for an ER includes an electro-pneumatic source of pressure or atmosphere responsive to an electrical equalizing pressure control signal and a pilot valve selectively connecting the electro-pneumatic source or atmosphere to the equalizing reservoir in response to pressure in a pilot port of the first pilot valve. A magnetic valve is provided having a first input connected to a second source of pressure, a second input connected to atmosphere and an output connected to the pilot port of the first pilot valve. At least one penalty valve is connected to the pilot input of the first pilot valve and is responsive to a penalty signal to connect the pilot input to atmosphere. 
     The one or more penalty valves may be connected to the pilot port of the first pilot valve via the first input of the magnetic valve or may be connected to the pilot port of the first pilot valve at the output of the magnetic valve. The penalty valves are responsive to an electric penalty signal or a pneumatic penalty signal. One or more of the penalty valves may be connected to the pilot port of the first pilot valve by a suppression or second pilot valve which selectively disconnects the penalty valve from the pilot port in response to a suppression signal. A pilot port of the second pilot valve may either be controlled by a second magnetic valve or by a pneumatic source of a suppression signal. 
     These and other aspects of the present invention will become apparent from the following detailed description of the invention, when considered in conjunction with accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a schematic of a controller for an equalizing reservoir showing a first embodiment of the present invention. 
     FIG. 2 is a schematic of a controller for an equalizing reservoir illustrating a second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 and 2 show two embodiments of a controller for an equalizing reservoir. All of the elements are the same. The difference is in the connection of the penalty valve system to the equalizing reservoir control pilot valve. The controller for the equalizing reservoir is only part of a train brake control system, as illustrated in the previously mentioned patents. This equalizing controller may be used with systems other than those illustrated in the aforementioned patents. 
     As shown in the figures, an equalizing reservoir (ER)  10  is connected to and controls a brake pipe relay  12  via line  11 . The brake pipe relay  12  controls a brake pipe (BP). Also, connected to the brake pipe relay  12  is exhaust (EX) and main reservoir (MR) via line  13 . As is well known, the brake pipe relay  12  receives a reference signal  11  from the ER  10  and produces an appropriate pressure in the brake pipe (BP) using exhaust (EX) and pressure from the main reservoir (MR) via line  13 . Reduction in the pressure in the ER  10  produces a reduction in the pressure in the brake pipe (BP), which reflects a brake application. An increase in the pressure in ER  10  creates an increase in the pressure in brake pipe (BP), which is a brake release signal. The brake pipe cut off and charging circuit have been deleted for sake of clarity. How this is accomplished is well-known, as illustrated in the abovementioned patents. 
     The main reservoir (MR) is also connected via line  13  and filter  14  to an electro-pneumatic source of pressure or atmosphere  16 , which is responsive to an electrical equalizing pressure control signal. An electro-pneumatic or magnetic apply valve  18  and an electro-pneumatic or magnetic release valve  20  are shown connected together at a common output  17 . The input to the release valve  20  is exhaust (EX), and the input to the apply valve  18  is from the output of the filter  14  via line  15 . Even though a pair of valves  18  and  20  are shown in the electro-pneumatic source of pressure or atmosphere  16 , a single valve may be used or any other electro-pneumatic control system to provide a desired equalizing reservoir pressure signal. The output  17  is connected to an equalizing reservoir transducer (ERT). 
     The output  17  is also provided as a first input to the equalizing reservoir pilot valve (PVER)  22 . The other input is from atmosphere or exhaust (EX). The output of the PVER  22  is provided on line  19  to the ER  10 . The pilot port or pilot line  23  of valve  22  is connected to an electro-pneumatic or magnetic valve  24 . A second pressure source at the input of  24  on line  21  is from the main reservoir (MR) and filter  14  through a choke or restriction C 3 . As will he explained below, the restriction C 3  prevents the charging of the pilot port  23  when the penalty valve connects the pilot port  23  to exhaust (EX) or atmosphere. 
     The equalizing magnetic valve (MVER)  24  is shown in its deactivated condition, wherein the pilot port  23  is connected to exhaust (EX). Upon activation, the source is connected to the pilot valve  22  to move it from its shown exhaust position to its control pressure position connecting its output  19  to line  17 . The control of the apply valve  18  and release valve  20  determine the pressure provided through the open pilot valve  22  to the ER  10 . These connections and operations are well known in the prior art, as shown in the previously discussed patents. 
     Also, connected to pilot port  23  of the PVER  22  are pneumatic penalty valve  26  and electric or electro-pneumatic penalty valve  28  via lines  27  and  29  to penalty pilot line  25 . The pneumatic penalty valve  26  may be an operator-activated valve or deadman&#39;s valve, pedal valve or other various safety valves within the locomotive. The electric penalty valve  28  may be other valves activated by the locomotive control system in response to a penalty condition. Both of the valves  26  and  28  are responsive to a penalty input signal to connect their respective output lines  27  and  29  and, consequently, penalty pilot line  25  to exhaust (EX). This removes the pilot signal from pilot port  23  of the PVER  22  causing it to return to the shown position connecting its output  19  and the ER  10  to atmosphere or exhaust (EX). This causes the brake pipe relay  12  to reduce the brake pipe pressure causing a brake application. It should be noted that penalty valves  26  and  28  are connected directly to penalty pilot line  25  and, therefore, are considered non-suppressible in that they will automatically cause a brake application. 
     An electro-pneumatic suppressible penalty valve (SPV)  30  is also connected to penalty pilot line  25  via line  31  and suppression pilot valve (PVSU)  32  and its output  33 . The PVSU  32  is responsive to a pilot signal  35  to disconnect its input or SPV  30  from its output and, consequently, control of the pilot port  23  of the PVER  22 . Typical examples of suppressible penalty valves are operator-activated valves, dead man&#39;s valves, pedal valves or other safety valves. The pressure value in the penalty pilot line  25  to pilot port  23  is monitored by a pressure transducer (PT). This may be used in controlling the ER  10  using the electro-pneumatic source  16  and indicates that a penalty valve has been activated connecting the penalty pilot line  25  to exhaust (EX). 
     The penalty valves  26 ,  28  and  32  are merely examples and may be electric, electro-pneumatic or pneumatic. The number of valves may be varied. The point is that there are one or more non-suppressible penalty valves and one or more suppressible penalty valves. 
     The pilot port  35  of PVSU  32  is connected to the higher of two signals from double-check valve (DCV)  36 . One input to the DCV  36  is from the brake cylinder (BC) via line  37 . A brake cylinder transducer (BCT) is also provided. The other input to the DCV  36  is from a magnetic or electro-pneumatic valve (MV 26 )  38 . The input to the MV 26  magnetic valve  38  is from the main reservoir (MR) via line  13 . The MV 26  magnetic valve  38  is shown in its deactivated condition providing atmosphere as its input to the DCV  36 . Normally, the brake cylinder is released, and its input to DCV  36  is also at atmosphere. Thus, the PVSU  32  is in its position shown connecting the SPV  30  to penalty pilot line  25 . If brakes are applied and there is pressure in the brake cylinder (BC), DCV  36  will provide pilot pressure on pilot port  35  of the PVSU  32  activating it to disconnect the SPV  30  from the output  33  and penalty pilot line  25 . 
     In response to a suppression electric signal, the MV 26  magnetic valve  38  will be activated moving from the shown position connecting the main reservoir (MR) via lines  13  and  39  to the DCV  36 . This provides pressure on pilot port  35  of the PVSU  32 , again disconnecting the SPV  30  from line  33  and penalty pilot line  25 . One source of electric signal to activate the MV 26  magnetic valve  38  would be the automatic brake handle. Brake handle positions of suppress and above would cause an activation of MV 26  magnetic valve  38 . These positions, as is well known, are Suppression, Handle Off and Emergency brake application. Other control signals may be provided to the MV 26  magnetic valve  38  to suppress or cut off the SPV  30  from controlling the penalty pilot line  25 . 
     An added feature to provide feedback of the condition or position of the MV 26  magnetic valve  38  is the use of PV 26  pilot valve  40 . Its pilot port  41  is connected to the output of the MV 26  magnetic valve  38 . The PV 26  pilot valve  40  is shown in its unpiloted position wherein its output  43  is connected to exhaust (EX). When MV 26  magnetic valve  38  moves to its suppression mode, pressure pilot port  41  moves PV 26  pilot valve  40  to its second position connecting the main reservoir (MR) via line  13  to its output  43 . This output signal D 26  is provided back to a control or an event recorder. 
     A controller  50  is provided. This controller provides all of the control signals to the various electro-pneumatic or magnetic valves and receives feedback from each of the transducers. Controller  50  is illustrated as a single block and may be the controller of the brake system, which may be a single controller or may be plural distributive controllers. Portions of the controller  50  may be on a module, which includes the controller for the ER  10  with other portions of the controller  50  being part of a system controller. Controller  50  is also shown controlling the electro-pneumatic penalty valves. Again, this would generally be performed by the brake system controller versus a distributive controller portion of the ER  10 . 
     FIG. 2 includes all of the same elements as FIG.  1 . The difference is that the penalty pilot line  25  is not connected at the output of the MVER magnetic valve  24 , as in FIG. 1, but is connected to the input  21  of the MVER magnetic valve  24 . The non-suppressible penalty valves  26 ,  28  are still connected directly to the penalty pilot line  25 , and the suppressible penalty valve  30  is connected through PVSU piloted suppression valve  32 . 
     When MVER magnetic valve  24  is not activated, exhaust is connected to pilot line  23  of the PVER valve  22  thus connecting its output  19  and ER  10  to exhaust (EX). This would produce the same results whether one of the penalty valves is activated or not. When MVER magnetic valve  24  is activated connecting its input  21  to the pilot line  23 , main reservoir pressure is provided on the pilot valve  23  connecting its output  19  to the electro-pneumatic source of pressure  16 . The penalty valves  26 ,  28  and  30  control the penalty pilot line  25  at the input of MVER valve  24 . When one of the penalty valves is activated, line  25  is connected to atmosphere bringing down the input to MVER valve  24  and, consequently, the pilot port  23  of PVER valve  22 . 
     Thus, the operation of the systems in FIGS. 1 and 2 are the same. Both provide a pneumatic actuated braking in response to a penalty condition whether it is an electro-pneumatically or pneumatically sensed penalty. The primary advantage of embodiment 1 is that it allows the controller to prevent a continuous exhaust of MR out of an open penalty valve. The controller can detect a penalty condition via PT and act to de-energize (close) MVER valve  24 , thereby preventing any further exhaust of air. This also prevents a continuous exhaust of air when the controller (and magnetic valve  24 ) are in a powered off condition. This would allow an unpowered locomotive to be hauled unmanned with an open foot valve, for instance. 
     Although the present invention has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The scope of the present invention is to be limited only by the terms of the appended claims.