Fastening device for footwear

Abstract

A fastening device for footwear includes a hook element with a major tooth and a minor tooth, a releasing element, a boosting cover, a base and a strap with teeth. Each tooth has an inclining surface and a vertical surface. When the hook element is pressed, the major tooth and the miner tooth are engaged with the inclining surface of the teeth alternately to push the strap to move backward. When the boosting cover is bent up, the boosting tooth is engaged with the vertical surface of the teeth to push the strap to move forward. When the releasing element is pulled up, the strap is completely released from the base.

What is claimed is: 
     
         1 . A fastening device for footwear comprising:
 a hook element, a major tooth formed on the front-bottom of the hook element, a miner tooth formed on the rear-bottom of the hook element, a first pivotal hole defined on the lateral of the hook element therethrough and located between the major tooth and the miner tooth;   a releasing element having a receiving hole at one end thereof for receiving the hook element, two ribs formed on two sides of the releasing element and abutted against two sides of the receiving hole, a second pivotal hole defined on the lateral of the rib, the second pivotal holes of the ribs aligned to the first pivotal holes of the hook element, a first pin with a first torsion spring passing through the second pivotal holes and the first pivotal holes to pivot the hook element on the releasing element, two ends of first torsion spring abutted against the hook element and the releasing element respectively, a pair of pivotal protrusions formed at another end of the releasing element and the pivotal protrusions located between the two ribs;   a boosting cover having a boosting tooth in front of the boosting cover, two pivotal portions extruded from the bottom of the boosting cover, a connecting member having a plurality of fourth pivotal holes at two ends therethrough, the fourth pivotal holes aligned to the pivotal portions and the pivotal protrusions respectively, a second pin with a second torsion spring and a third pin with a third torsion spring passing through the pivotal protrusions and the fourth pivotal holes, the fourth pivotal holes and the pivotal portions respectively to pivot the releasing element on the boosting cover, the second torsion spring being between the releasing element and the connecting member, the third torsion spring being between the connecting member and the boosting cover;   a base having two lateral walls at two sides respectively, the boosting cover pivoted on the base by the second pin via the connecting member, the releasing element and the hook element located between the two lateral walls; and   a strap placed into the base and between the two lateral walls, a sequence of teeth formed on the strap, the miner tooth engaging with the teeth for fastening the strap;   wherein the hook element is pressed so that the major tooth and the miner tooth is engaged with the inclining surface of the teeth alternately to push the strap to move backward; the boosting cover is bent up so that the boosting tooth is engaged with the vertical surface of the teeth to push the strap to move forward; the releasing element is pulled up so that the boosting cover and the hook element are both disengaged with the strap simultaneously and the strap is completely released from the base.   
     
     
         2 . The fastening device for footwear as claimed in  claim 1 , wherein the connecting member is H-shaped, the fourth pivotal holes at one end of the connecting member aligned to the pivotal portions for connecting to the third pin, the fourth pivotal holes at another end of the connecting member aligned to the pivotal protrusions for connecting to the second pin. 
     
     
         3 . The fastening device for footwear as claimed in  claim 2 , wherein the connecting member has a block portion, two ends of the second torsion spring being fastened at the block portion, a supporter disposed on the inner side of the lateral wall and located at one end of the base, the second pin positioned on the two supporters, two ends of the third torsion spring being fastened at the bottom of the supporters. 
     
     
         4 . The fastening device for footwear as claimed in  claim 1 , wherein a rib space is defined on the lateral wall of the base for receiving the ribs of the releasing element. 
     
     
         5 . The fastening device for footwear as claimed in  claim 1 , wherein a notch is defined on the inner side of the lateral wall at another end of the base and the shape of notch is corresponding to the cross-sectional shape of the minor tooth for positioning the minor tooth of the hook element. 
     
     
         6 . The fastening device for footwear as claimed in  claim 4 , wherein the notch is defined on the inner side of the lateral wall at another end of the base and the shape of notch is corresponding to the cross-sectional shape of the minor tooth for positioning the minor tooth of the hook element. 
     
     
         7 . The fastening device for footwear as claimed in  claim 1 , wherein each of the teeth has an inclining surface and a vertical surface, a trough formed between each pair of the neighboring teeth, the minor tooth being positioned in the trough for fastening the strap. 
     
     
         8 . The fastening device for footwear as claimed in  claim 4 , wherein each of the teeth has an inclining surface and a vertical surface, the trough formed between each pair of the neighboring teeth, the minor tooth being positioned in the trough for fastening the strap. 
     
     
         9 . The fastening device for footwear as claimed in  claim 5 , wherein each of the teeth has an inclining surface and a vertical surface, the trough formed between each pair of the neighboring teeth, the minor tooth being positioned in the trough for fastening the strap. 
     
     
         10 . The fastening device for footwear as claimed in  claim 6 , wherein each of the teeth has an inclining surface and a vertical surface, the trough formed between each pair of the neighboring teeth, the minor tooth being positioned in the trough for fastening the strap.