Abstract: A pneumatically piloted retainer valve for bottling brake cylinder pressure that can be set and released in response to changes in the brake pipe pressure. Pneumatically piloted retainer valve provides a brake cylinder pressure retaining function that bottles applied brake cylinder pressure in the brake cylinder when brake pipe pressure is less than a predetermined cut-in pressure. Pneumatically piloted retainer valve includes a retainer valve movable between a reset position, where brake cylinder pressure is in communication with exhaust and a bottle position, wherein brake cylinder pressure is isolated from exhaust. A retainer pilot control valve provides for piloting of the retainer valve in response to a predetermined reduction or threshold increase in brake pipe pressure.

Abstract: An intelligent locomotive brake control system which selects and optimizes use of dynamic, independent, and automatic brakes on the locomotive to assure intended brake power, to minimize in-train forces, minimize brake component wear, and to automate standard train brake protocol. The system may be programmed to alter an automatic brake application commanded by a train driver to omit or reduce the amount of the automatic brake application in favor of a dynamic brake application, and independent brake application, or combination thereof.

Abstract: An air dryer for a locomotive air supply system that includes a controller programmed to initiate a sleep mode that inhibits the air dryer and de-energizes all valves. The controller determines when it is appropriate to enter into sleep mode based on various conditions of the locomotive air supply system. More specifically, the controller is programmed to calculate whether the air dryer should be placed into sleep mode based on operational characteristics of the locomotive air supply system that are indicative that the system has been idled. The initiation of an air dryer sleep mode by the controller prevents undesirable venting of air from the air supply system and unnecessary usage of locomotive battery power.

Abstract: An intelligent locomotive brake control system which selects and optimizes use of dynamic, independent, and automatic brakes on the locomotive to assure intended brake power, to minimize in-train forces, minimize brake component wear, and to automate standard train brake protocol. The system may be programmed to alter an automatic brake application commanded by a train driver to omit or reduce the amount of the automatic brake application in favor of a dynamic brake application, and independent brake application, or combination thereof.

Abstract: A computer controlled locomotive brake (CCB) configured for setting and releasing the automatic parking brakes of the railcars of a train. The CCB may initially recharge the brake pipe to a pressure slightly less than the parking brake unlatch pressure. The CCB may then continue charging to this level until the brake pipe flow, measured at the CCB on the controlling locomotive and the brake pipe pressure on the last car, as measured by an end of train device, indicate that the pressure in the braking system reservoirs are substantively equal to the brake pipe pressure. Once the reservoirs are substantively charged, the CCB may complete the brake release and recharge by recharging the brake pipe pressure to its final charge so that all parking brakes are released and the train has sufficient braking system recharge to safely control movement of the train.

Abstract: An air dryer having a heater associated with its inlet and exhaust valves to prevent freezing at cold temperatures. The air dryer includes a temperature sensor associated with the valve block and a controller that can inhibit the operation of the valves when the temperature falls is a predetermined threshold until the heater can sufficiently warm the valve block. To prevent overheating of the heater, the controller can adjust the duty cycle of the heater as the inlet air temperatures increases.

Abstract: An air dryer having a heater element associated with its valves to prevent freezing at cold temperatures. The air dryer includes a temperature sensor and an electronic controller that reads the temperature sensor during normal operations and selectively opens and closes certain of the valves when the temperature falls below a predetermined threshold to enter a safe mode that avoids freezing of the valves during operation. If an exhaust valve is open when safe mode is entered, the corresponding inlet valve is closed, both of the exhaust valves are closed, and the other inlet valve if opened. If an exhaust valve is not open, both inlet valves are opened and both exhaust valves are closed.

Abstract: An air dryer having a heater element associated with its valves to prevent freezing at cold temperatures. The air dryer includes a temperature sensor and an electronic controller that reads the temperature sensor during normal operations and selectively opens and closes certain of the valves when the temperature falls below a predetermined threshold to enter a safe mode that avoids freezing of the valves during operation. If an exhaust valve is open when safe mode is entered, the corresponding inlet valve is closed, both of the exhaust valves are closed, and the other inlet valve if opened. If an exhaust valve is not open, both inlet valves are opened and both exhaust valves are closed.

Abstract: An air dryer having a heater element associated with its valves to prevent freezing at cold temperatures. The air dryer includes a temperature sensor and an electronic controller that reads the temperature sensor and inhibits actuation of the valves whenever the temperature of valves is below freezing or a predetermined temperature that indicates a risk for freezing until the valves have been sufficiently warmed by the heater to avoid freezing during operation.

Abstract: An air dryer having a heater element associated with its valves to prevent freezing at cold temperatures. The air dryer includes a temperature sensor and an electronic controller that reads the temperature sensor and inhibits actuation of the valves whenever the temperature of valves is below freezing or a predetermined temperature that indicates a risk for freezing until the valves have been sufficiently warmed by the heater to avoid freezing during operation.

Abstract: A locomotive brake system includes a brake cylinder with an integrated parking brake; a main reservoir; and a brake system controller for controlling the pressure in the brake cylinder. The brake system uses main reservoir pressure to pressurize the brake cylinder to achieve the parking brake output force using the brake cylinder.

Abstract: A control system for an air dryer that switches the flow and counter flow of air through each of two desiccant towers in response to a drying cycle period that is proportional to the saturation partial pressure of water vapor in the inlet air stream as determined by the temperature of the stream of air in the inlet of the air dryer. The system may also include a proximity sensor positioned in the back flow check valve between the first main reservoir and the second main reservoir to further adjust the regeneration cycle period according to the flow rate through the air dryer.

Abstract: A railway air dryer that switches the flow and counter flow of air through each of two desiccant towers in response to the actual humidity of air being dried by the air dryer. The air dryer includes a humidity sensor, a temperature sensor in the outlet air, and a temperature sensor in the inlet air stream to determine when to initiate the regeneration of the desiccant. The air dryer system is generally specified to provide some minimum drying performance, for example 40° C. dew point suppression.

Abstract: An air dryer having a heater element associated with its valves to prevent freezing at cold temperatures. The air dryer includes a temperature sensor and an electronic controller that reads the temperature sensor and inhibits actuation of the valves whenever the temperature of valves is below freezing or a predetermined temperature that indicates a risk for freezing until the valves have been sufficiently warmed by the heater to avoid freezing during operation.

Abstract: An air dryer for a locomotive air supply system that includes a controller programmed to initiate a sleep mode that inhibits the air dryer and de-energizes all valves. The controller determines when it is appropriate to enter into sleep mode based on various conditions of the locomotive air supply system. More specifically, the controller is programmed to calculate whether the air dryer should be placed into sleep mode based on operational characteristics of the locomotive air supply system that are indicative that the system has been idled. The initiation of an air dryer sleep mode by the controller prevents undesirable venting of air from the air supply system and unnecessary usage of locomotive battery power.

Abstract: An air dryer system for a locomotive having optimized purge air control over a twin tower desiccant-type air dryer. The computer controlled locomotive brake system is used to determine when the air dryer is being used and approximately how much air flow has actually passed through the active tower of the dryer using the air consumption state, the change of pressure in the second main reservoir, the air compressor on/off state, the total accumulated time of air flow since last purge cycle, and/or the calculated air flow through the air dryer since the last purge cycle. When the actual air flow reaches the capacity of the active tower of the air dryer, the computer controlled locomotive brake system commands the air dryer to perform a purge cycle. The system thus maximizes the use of each tower in the air dryer rather than switching according to a preset time period.

Abstract: An on-board train brake safety monitoring and fault action system that compares actual train brake power with expected train brake power to provide real time reporting to the train driver of the margin between the actual brake power and a safe threshold. The system may be configured to automatically make a full service brake penalty if the actual brake system power is less than a safe brake power threshold, such as those required by government regulations, or to adjust the braking system to improve actual brake efficiency. The on-board train brake monitoring system may optionally receive data from wayside hot and cold wheel detector systems to augment the actual brake power measurements.

Abstract: An air dryer system for a locomotive having optimized purge air control over a twin tower desiccant-type air dryer. The computer controlled locomotive brake system is used to determine when the air dryer is being used and approximately how much air flow has actually passed through the active tower of the dryer using the air consumption state, the change of pressure in the second main reservoir, the air compressor on/off state, the total accumulated time of air flow since last purge cycle, and/or the calculated air flow through the air dryer since the last purge cycle. When the actual air flow reaches the capacity of the active tower of the air dryer, the computer controlled locomotive brake system commands the air dryer to perform a purge cycle. The system thus maximizes the use of each tower in the air dryer rather than switching according to a preset time period.

Abstract: A brake cylinder limiting valve having a first portion that determines actual brake cylinder pressure and a second portion that determines intended brake cylinder pressure based on brake pipe pressure reduction. The two portions are combined so that brake cylinder pressure will be vented if the actual brake cylinder pressure exceeds intended brake cylinder pressure by a predetermined threshold amount, which is preferably two and one-half times the brake pipe pressure reduction. An exhaust cut-off valve may be used to prevent venting of the brake cylinder pressure if it falls below a predetermined value.

Abstract: A brake cylinder maintaining system produces a brake cylinder reference pressure based on the difference between the brake pipe pressure and the auxiliary reservoir pressure and then feeds that pressure to a choke and a volume so that the ratio of the reference area of the choke to the volume of stored brake cylinder reference pressure is substantively equal to the ratio of a brake cylinder charging valve area to the brake cylinder volume. The resulting reference pressure may be used to adjust brake cylinder pressure by providing the reference pressure to a standard quick service limiting valve or to a relay that can selectively charge or exhaust the brake cylinder.