Patent attributes
A coupling for joining conduits together is disclosed, the coupling having male and female fitting portions held in engagement by a self-locking roller cam positioned on the female portion. The roller cam has a cam body rotatable about an axis offset from the center of the cam body. An annular roller surrounds the cam body and is rotatable relatively to it. An outwardly facing surface on the roller engages an opposing concave surface on the male portion of the coupling. Reaction forces between the roller and the opposing surface operate along a line of action initially positioned to one side of the offset axis to create a torque opposing rotation of the cam into engagement with the opposing concave surface. Further forced rotation of the cam into engagement with the opposing concave surface causes the line of action of the reaction force to shift to an opposite side of the offset axis thereby creating a torque which causes rotation of the cam body into engagement with the opposing concave surface to retain the male fitting portion within the female fitting portion.
