Abstract: A coupler attached to the articulating arm linkage of an excavator may be coupled to a bucket or other work implement, the coupler having a rotator carried between and rotatable relative to a pair of body parts. The rotator has an elongated channel for receiving a pin of the work implement and carries a crank which may be manually turned or moved by a hydraulic cylinder to drive the rotator. In one position, the channel is open for permitting entry and removal of the pin and in other positions is closed to lock the pin from exiting. The coupler includes another pin receiving slot so that a second pin of the work implement may be received. The slot and the channel of the rotator in the open position are inclined relative to one another. The crank in one embodiment has a number of projections for cooperating with elements of a hand operated lever to drive the rotator. When the hand operated lever is not in use, it may be stored conveniently within the coupler to serve as a locking device.