Coupler for coupling an attachment to a dipper arm

Abstract

A quick hitch coupler for coupling an attachment to a dipper arm of an excavator, the quick hitch coupler comprising: (a) a body member adapted for coupling to the dipper arm, (b) a fixed engaging jaw mounted on the body member for engaging a first one of a pair of coupling pins mounted on the attachment, (c) a movable engaging jaw mounted on the body member for engaging a second one of the pair of coupling pins of the attachment, the movable engaging jaw being movable between an engaged state with the movable engaging jaw engaging the second coupling pin while the fixed engaging jaw engages the first coupling pin for coupling the attachment to the coupler, and a disengaged state for disengaging the second coupling pin, (d) a latch co-operable with the fixed engaging jaw for retaining the first coupling pin of the attachment engaged in the fixed engaging jaw the latch being alternately operable in a latched state co-operating with the fixed engaging jaw for retaining the first coupling pin in the fixed engaging jaw, and an unlatched state for releasing the first coupling pin from the fixed engaging jaw, (e) an urging means for urging the latch into the latched state, (f) a release block being movable on (and relative to) a guide, the release block being movable on the guide between a non-active position in which the latch remains in the latched state and an active position where the release block abuts against the latch to move the latch from the latched state to the unlatched state against the urging action of the urging means, (g) a drive means generating an amount of displacement: (i) for moving the movable engaging jaw from the engaged state to the disengaged state, and (ii) for moving the release block on the guide from the non-active position to the active position. The drive means generates an amount of displacement for moving the movable engaging jaw but the release block is not moved and a second stage where the drive means generates an amount of displacement for moving the movable engaging jaw above a threshold amount where the release block is moved.

Dependencies are inferred from the claim text.