Quick coupler for connecting an implement that is provided with an adapter each, to an earth-moving vehicle such as an excavator, which quick coupler comprises: a housing, at least one coupling claw oriented in a first direction for engaging in an associated adapter axle of said adapter, a locking element that can be moved between a locking position and an opening position thereof for locking said quick coupler in place in said adapter, which locking element is oriented in a second direction, and a securing mechanism for securing said adapter axle of said adapter in said coupling claw when said adapter axle is in said coupling claw in the closing position of said quick coupler, said securing mechanism including at least one movable securing element that is pivotable between an opening position and a securing position thereof about a first axis of rotation, said securing element having a first contact region in the closing position of said adapter axle and in the securing position of said securing element via which said securing element can bear on said adapter axle if required, said first contact region being arranged with respect to the axis of rotation in such a manner that, when said adapter axle is loaded in the direction out of the closing position in said coupling claw of said quick coupler, the force resulting from this load will urge said securing element, via said first contact region, further into the securing position about the axis of rotation, which first contact region is arranged, with respect to a plane that is perpendicular to a straight line which extends perpendicular to said axis of rotation and to a central axis of said coupling claw, on one side of said plane and said axis of rotation is arranged on the other side of said plane when said adapter axle is in the closing position of said coupling claws, with said plane passing through the claw axis, characterized in that said first contact region is arranged in such a manner that, when said adapter axle is in the closing position in said coupling claw of said quick coupler, said first contact region will be arranged above a straight line that is perpendicular between the axis of rotation of said securing element and said claw axis. a housing, at least one coupling claw oriented in a first direction for engaging in an associated adapter axle of said adapter, a locking element that can be moved between a locking position and an opening position thereof for locking said quick coupler in place in said adapter, which locking element is oriented in a second direction, and a securing mechanism for securing said adapter axle of said adapter in said coupling claw when said adapter axle is in said coupling claw in the closing position of said quick coupler, said securing mechanism including at least one movable securing element that is pivotable between an opening position and a securing position thereof about a first axis of rotation, said securing element having a first contact region in the closing position of said adapter axle and in the securing position of said securing element via which said securing element can bear on said adapter axle if required, said first contact region being arranged with respect to the axis of rotation in such a manner that, when said adapter axle is loaded in the direction out of the closing position in said coupling claw of said quick coupler, the force resulting from this load will urge said securing element, via said first contact region, further into the securing position about the axis of rotation, which first contact region is arranged, with respect to a plane that is perpendicular to a straight line which extends perpendicular to said axis of rotation and to a central axis of said coupling claw, on one side of said plane and said axis of rotation is arranged on the other side of said plane when said adapter axle is in the closing position of said coupling claws, with said plane passing through the claw axis, characterized in that said first contact region is arranged in such a manner that, when said adapter axle is in the closing position in said coupling claw of said quick coupler, said first contact region will be arranged above a straight line that is perpendicular between the axis of rotation of said securing element and said claw axis.