DUAL SEAL COUPLING APPARATUS FOR ENABLING QUICK MEASUREMENT OF BRAKE CYLINDER PRESSURE

摘要

A dual seal coupling apparatus enables quick measurement of brake cylinder pressure through a receiver assembly of a control valve. The receiver assembly has a receiver body, a check valve housed in the body and a cover whose removal renders the check valve accessible. The check valve is normally compressed against a check valve seat to provide a first seal that prevents leakage of the pressure. When moved away from its seat, the check valve provides access to the pressure. The apparatus includes a boss that protrudes from the cover and a male portion of a quick connect coupling. The boss defines a threaded bore aligned with the check valve when the cover is secured to the receiver body. The male portion includes a valve body and a valve stem. The valve body defines a valve bore and has a threaded end for screwing into the threaded bore of the cover. At its opposite end, the valve body is shaped to mate with a female portion of the quick connect coupling. The valve stem moves within the bores and its head is normally compressed against a valve stem seat. The head of the valve stem against the valve stem seat provides a second seal that further prevents leakage of the pressure. When the male and female portions are mated, the valve stem is moved away from its seat thereby moving the check valve away from its seat and providing access to and enabling measurement of the brake cylinder pressure.