Wire tightening apparatus

A wire tightening apparatus comprising:

• a housing part provided with a one-way ratchet gear along a circumferential direction at an inner circumference thereof;
• a reel part rotatably inserted into the housing part and allowing a wire to be selectively wound thereon;
• a rotation restriction part engaged with the ratchet gear, by which one-way rotation thereof is restricted, provided with a vertical movement support hole with upper and lower openings along a central portion thereof, and moving upward or downward by external force such that, when moving downward, the rotation restriction part is coupled to an upper portion of the reel part to rotate in an integrated manner;
• and
• a vertical movement support shaft part comprising a shaft body part coupled to a lower portion of the housing part, elastic pieces extending upward from an upper end of the shaft body part to be divided by a plurality of slits and passing through the vertical movement support hole, and pressure gradient protrusions protruding from outer surfaces of the elastic pieces to exceed an inner diameter of the vertical movement support hole so that the vertical movement support hole is elastically supported by elastic tightening and restoration of the elastic pieces,
• wherein a cover part is coupled to an upper portion of the rotation restriction part to vertically operate in a rotation direction in an integrated manner, hooking protrusions protrude from an inner circumference of a lower end of a sidewall portion of the cover part to be hook-coupled to a hook blade portion protruding from an outer circumference of the housing part, and the sidewall portion vertically extends so that the hooking protrusions and the hook blade portion have a separation distance corresponding to a lifting interval of the rotation restriction part.