US Patent 11751634 Fastening device and lace assembling method

A fastening device is provided. The fastening device includes a case, a spool, a knob and a locking unit. When the knob is rotated relative to the case in a fastening direction, the spool is not affected by the locking unit and is allowed to rotate in the fastening direction for fastening the lace. When the knob is rotated relative to the case in a loosening direction, the spool is allowed to freely rotate in the loosening direction to release the lace. As the knob is engaged with the housing via an engagement between the mounted portion and the engaged portion, the housing, the locking unit, the knob and the spool are combined and restricted.