Condition indicating system for railway car cushioning unit

A railway car cushioning system comprising,

• A) a hydraulic--pneumatic cushioning device for cushioning a railway car, said device comprising a cushioning device body having an interior chamber, a device piston in the chamber, a piston rod connected to the device piston and extending outwardly of the cushioning device body, and hydraulic fluid and a pressurized gas in the chamber;
• B) a pressure indicator mounted on said cushioning device body and located in communication with pressurized hydraulic fluid in the chamber, the pressure indicator including an indicator body, a movable member disposed in the indicator body including an exposed actuator pin and an indicator piston, a first switch contact on the actuator pin, a spring biasing the movable member toward the interior chamber, a seal between the movable member and indicator body, a first attachment member on the indicator body adjacent to the exposed actuator pin, a first electrical contact surface on the indicator body, the pressure indicator including a first electrical circuit path extending from the first electrical contact surface to the first switch contact;
• and
• C) a signal unit including a signal unit body, first and second terminals, a contact member, a second switch contact on the contact member, an insulator between the contact member the signal unit body, a second electrical contact surface on the signal unit body, a second electrical circuit path extending through the signal unit between a first terminal and the second electrical contact surface, and a third electrical circuit path extending through the signal unit from a second terminal to the second switch contact, a second attachment member on the signal unit body complimentarily engagable and disengagable with the first attachment member to mount the signal unit on the pressure indicator with the first and second electrical contact surfaces engaging each other and the second switch contact adjacent to the first switch contact such that movement of the movable member outwardly of the hydraulic--pneumatic cushioning device by pressurized hydraulic fluid moves the first switch contact into engagement with the second switch contact to form a closed electrical connection between said terminals.