Abstract: A push-to-connect coupler has a cylindrical coupler body with first and second radial flow passages separated by an internal partition, an inner valve assembly, and an outer sleeve assembly. The inner valve assembly includes a valve sleeve which cooperates with a cylindrical extension extending axially downstream from the partition to prevent leakage from the coupler body. When the nipple is inserted into the coupler socket, the nipple moves the valve sleeve axially upstream away from the distal end of the extension to allow fluid to flow between the extension and the valve sleeve to the nipple. The outer sleeve assembly includes a locking sleeve and a cylindrical slide valve surrounding the coupler body. The locking sleeve is spring-biased to urge locking balls into a groove on the nipple and retain the nipple in the coupler socket. The slide valve is slidable to selectively allow fluid to bypass a partition in the coupler body and flow to the nipple.

Abstract: A female quick disconnect coupling includes a locking mechanism which requires different forces to connect and disconnect a male coupling. A tubular housing is slidably mounted within a sleeve, and a pair of coil springs are mounted between the housing and the sleeve. Only one of the springs is compressed as the housing moves in one direction within the sleeve to permit a male coupling to be connected to the female coupling. Both springs are compressed as the housing moves in the other direction to permit the male coupling to be disconnected, thereby requiring a relatively high force to disconnect the couplings.