1. Field of the Invention
The present invention relates to a tightening device applied in footwear or clothing, and more particularly to an adjusting device for tightening or loosing laces and straps.
2. Description of Related Art
Referring to U.S. Pat. No. 6,289,558, a conventional tightening device for laces includes a knob, a plurality of gear wheels with ratchet sections, a reel and a releasable lock mechanism. The reel is rotatable for receiving the lace. The knob is connected to the gear wheels and the knob is moveable along an axis of rotation between an engaged position and a disengaged position relative to the releasable lock mechanism. The gear wheel drives the reel to wind or unwind the lace. When a user rotates the knob in the said first direction, the reel is also driven by the gear wheels to rotate in the first direction for winding the lace. In addition, the releasable lock mechanism prevents rotation of the reel in the said second direction for unwinding the lace when the knob is located at the engaged position relative to the releasable lock mechanism. In contrast, when the knob is moved to a disengaged position relative to the releasable lock mechanism along the axis of rotation, the reel is free to rotate in the second direction for unwinding the lace. Another conventional tightening device for helmet straps also includes a knob, a plurality of gear wheels with ratchet sections, two straps with teeth and a releasable lock mechanism. The only difference is that the gear wheels pull the two straps back and forth through the ratchet sections engaged the teeth of two straps. There is no reel in the tightening device for helmet straps.
The disadvantage of the conventional tightening device is as following:
1. The user needs to move the knob to one engaged position or one disengaged position at first, then the user can rotate the knob to wind or unwind the lace and the strap. Therefore, the user cannot directly rotate the knob to wind and unwind the lace and the strap.
2. The releasable lock mechanism might be broken easily after the knob is moving up and down frequently, and the knob might unexpectedly depart from the tightening device.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional.