Hand ejector

A hand ejector is a revolver design that is used on most double-action revolvers to this day. 
Design.
A hand ejector is characterized by a cylinder that swings out on a hinge (known as a crane) and requires the pushing of a concentric rod toward the cylinder to eject the spent cases from the cylinder. The term "hand ejector" (though not the design itself) was originated by Smith & Wesson to differentiate this class of revolver from the "top break" design, in which rotating the barrel / cylinder up and away from the gun's frame would "automatically" eject the cases.