Automatic latching lockout shaft sensing coupler

A coupler assembly for locking a shaft to a hub, comprising:

• a hub having a bore with a bore axis and a first slot axially spaced from a second slot, the first and second slots extending perpendicular to the bore axis;
• a collar concentrically disposed about the hub and defining a channel at its inner diameter, the collar being slidable along the hub from a released position to a locked position;
• a locking member movable in the first slot to engage a recess in the shaft when the shaft is inserted into the hub bore and the collar is in the locked position;
• and
• a collar latch assembly including a release member movable in the second slot perpendicular to the bore axis and a latch ring eccentrically disposed about the hub and the release member when the collar is in the released position so that one side of the latch ring engages a ledge of the hub which extends perpendicular to the bore axis and an opposite side of the latch ring engages a surface of the collar which extends perpendicular to the bore axis so that the collar is fixed in the released position, the collar being fixed in the released position until the shaft is inserted into the hub bore sufficiently to move the release member and the latch ring outward perpendicular to the bore axis to release the latch ring from engagement with the ledge and permit the collar to move to the locked position when the shaft is in a fully inserted position in which the locking members are seated in the recess of the shaft, the release member preventing the latch ring from engaging with the ledge in the fully inserted position of the shaft.