Abstract: Interchangeable internally gripping chucks for use in a machine applying non-rotative closures to containers, the machine having a multi-station rotary turret arrangement for receiving the containers from a feed conveyor. Each chuck is attached to a spindle in the rotary turret and includes spring loaded jaws for gripping a closure and seating it into or onto the upper portion of a container. The jaws are respectively biased radially outward by the spring loading means, and as the chuck descends and engages the inner edge of the closure, the jaws slip to grip the closure for pick-up and transport to the capping zone. The chuck further includes a releasing mechanism which is activated upon a "bottoming-out" of the chuck upon the top of the container. The releasing mechanism forces the jaws radially inward, disengaging them from the closure so that the chuck can be upwardly retracted from the closed container without any tendency to withdraw the closure, even when the closure has a loose fit.