US Patent 7353731 Quick release handlebar stem assembly for a bicycle

A quick release handlebar stem assembly for a bicycle comprises a stem having a first pivotal connecting portion, a clamping portion formed on the stem, and a clamping member is pivotally connected to the clamping portion, the clamping member is provided with a retained portion; a quick-release locking clamp pivotally coupled the first pivotal connecting portion of the stem; a retainer pivotally coupled to the quick-release locking clamp is provided with a retaining portion for locking the retained portion of the clamping member; wherein the retainer can hook the clamping member when rotating the quick-release locking clamp, so that the clamping member will cooperate with the clamping portion to clamp and release a handlebar of a bicycle.