Fastening device

Abstract

A fastening device includes a case unit, a spool, a connecting unit, a knob and an engaging unit. The case unit includes a wall forming a receiving space, a partition separates the receiving space into an upper chamber and a lower chamber, a through hole located at the partition, and a base detachably connected to at least one part of the wall. The spool is located at the lower chamber. The knob is connected to the connecting unit. The engaging unit is located at the upper chamber. After the connecting unit is inserted into the spool, the through hole and the engaging unit to couple to the knob, the partition, the spool, the connecting unit, the knob and the engaging unit are connected integrally without being separated from each other while the base is separated from the at least one part of the wall.

What is claimed is: 
     
         1 . A fastening device, comprising:
 a case unit, comprising:
 a wall; and 
 a base detachably connected to the wall; 
   a spool rotatably positioned within the case unit for a lace to be wound thereabout;   an engaging unit received in the case unit for prohibiting the spool from rotating in a first direction;   a knob operably coupled with the spool so that a rotation of the knob in a second direction effects a rotation of the spool within the case unit to wind the lace about the spool.   
     
     
         2 . The fastening device of  claim 1 , further comprising a gear assembly received in the case unit, wherein the case unit further comprises a plurality of inner teeth located in the wall, and the gear assembly is coupled to the inner teeth, the spool and the knob for transferring a force from the knob to rotate the spool in the second direction for tensioning the lace. 
     
     
         3 . The fastening device of  claim 2 , wherein the gear assembly comprises a sun gear and a plurality of planetary gears, the sun gear is coupled to the knob, the planetary gears are disposed at the spool, each of the planetary gears comprises a plurality of gear teeth for engaging with the inner teeth, as the knob is rotated in the second direction, the sun gear drives the planetary gears to rotate the spool in the second direction, and as the knob is moved upward, the planetary gears are not affected by the engaging unit, and the lace is allowed to be released. 
     
     
         4 . The fastening device of  claim 3 , wherein a length of each of the inner teeth is substantially longer than a length of each of the gear teeth. 
     
     
         5 . The fastening device of  claim 3 , wherein as the knob is moved upward, the engaging unit is disengaged from the knob. 
     
     
         6 . The fastening device of  claim 5 , wherein as the knob is moved upward, the sun gear is coupled to the planetary gears. 
     
     
         7 . The fastening device of  claim 1 , further comprising a connecting unit inserted into the spool and coupled to the knob. 
     
     
         8 . The fastening device of  claim 7 , wherein the connecting unit comprises a central shaft, and the spool further comprises:
 a hollow body, comprising an inner surface forming a hollow space, wherein the hollow space is configured for the central shaft to insert therein;   an upper ring portion protruding outward from one of two ends of the hollow body;   a lower ring portion protruding outward from the other one of the two ends of the hollow body; and   an engaging portion protruding from the inner surface toward the hollow space to couple to the central shaft;   wherein a winding track is formed between the upper ring portion and the lower ring portion.   
     
     
         9 . The fastening device of  claim 8 , wherein the central shaft comprises a positioning protrusion, when the knob is in a first position, the positioning protrusion is located at one of two sides of the engaging portion, and when the knob is switched from the first position to a second position, the engaging portion is displaced by the positioning protrusion such that the positioning protrusion is switched to the other one of the two sides of the engaging portion.