A method and apparatus for piecing a broken end of yarn at an open end spinning station utilizing a piecing cart servicing the spinning station. To repair the yarn break, a defined yarn length is unwound off the winding bobbin and is temporarily stored in a yarn reservoir disposed between a yarn draw-off device and a lap drive of the piecing cart. Subsequently, the winding bobbin is acceleratively driven by the lap drive sufficiently in advance of actuating the yarn draw-off device to achieve a predetermined winding speed as of the time the withdrawal of spun yarn from the spinning unit resumes.