Apparatus for opening/closing chin protection bar of safety helmet and safety helmet having the same

Abstract

There is provided an apparatus for opening/closing a chin protection bar installed in a helmet cap having a front opening, the apparatus including: a fixing unit which is fixed to the helmet cap and includes a movable shaft guide having an elongated hole shape and a pivoting guide formed approximately vertical to the movable shaft guide; and a pivoting unit which is fixed to the chin protection bar and includes a first connecting unit slidably inserted into the movable shaft guide and a second connecting unit slidably inserted into the pivoting guide, wherein the pivoting guide has a straight line shape, and the second connecting unit moves back and forth in a straight line in the pivoting guide and the first connecting unit moves back and forth in a straight line in the movable shaft guide according to the straight-line back-and-forth movement of the second connecting unit.

1 . An apparatus for opening/closing a chin protection bar installed in a helmet cap having a front opening, the apparatus comprising:
 a fixing unit which is fixed to the helmet cap and includes a movable shaft guide having an elongated hole shape and a pivoting guide formed approximately vertical to the movable shaft guide; and   a pivoting unit which is fixed to the chin protection bar and includes a first connecting unit slidably inserted into the movable shaft guide and a second connecting unit slidably inserted into the pivoting guide,   wherein the pivoting guide has a straight line shape, and   the second connecting unit moves back and forth in a straight line in the pivoting guide and the first connecting unit moves back and forth in a straight line in the movable shaft guide according to the straight-line back-and-forth movement of the second connecting unit.   
   
   
       2 . The apparatus of  claim 1 , wherein if the second connecting unit moves from one end of the pivoting guide to the middle portion thereof, the first connecting unit is lifted from a lower side of the movable shaft guide to a upper side thereof and if the second connecting unit moves from the middle portion of the pivoting guide to the other end thereof, the first connecting unit is lowered from the upper side of the movable shaft guide to the lower side thereof. 
   
   
       3 . The apparatus of  claim 1 , wherein the first connecting unit of the pivoting unit includes a first plate and a first shaft part connected to a part of a lower side of the first plate, and the second connecting unit includes a second plate and a second shaft part connected to a part of a lower side of the second plate. 
   
   
       4 . The apparatus of  claim 1 , wherein the movable shaft guide of the fixing unit includes a first hole into which the first plate can be inserted and a second hole, which has approximately the same width as that of the first shaft and is elongated in order for the first connecting unit passing through the first hole to move in a straight line. 
   
   
       5 . The apparatus of  claim 4 , wherein the pivoting guide of the fixing unit has a stepped protrusion, whereby the second plate passing through the pivoting guide slides while being hooked on the stepped portion so as to prevent the second connecting unit from being separated from the pivoting guide. 
   
   
       6 . The apparatus of  claim 5 , wherein if the first connecting unit is disposed in one end of the second hole in a direction opposite to the first hole, the second connecting unit is elastically supported against the stepped portion. 
   
   
       7 . The apparatus of  claim 1 , wherein a stopper protrusion for limiting a rotation of the chin protection bar is formed in one side of the pivoting unit and a stopper hook corresponding to the stopper protrusion is formed in one side of the fixing unit. 
   
   
       8 . A safety helmet comprising:
 a helmet cap having a front opening;   a chin protection bar which is pivotably fixed at the helmet cap for protecting a wearer's chin; and   a chin protection bar opening/closing apparatus which serves as a pivoting shaft of the chin protection bar and at the same time allows the chin protection bar to rotate while being spaced apart from the helmet cap by a predetermined distance,   wherein the chin protection bar opening/closing apparatus includes:   a fixing unit which is fixed at the helmet cap and has a long hole-shaped movable shaft guide and a pivoting guide formed approximately vertical to the movable shaft guide; and   a pivoting unit which is fixed at the chin protection bar and has a first connecting unit slidably inserted and connected to the movable shaft guide and a second connecting unit slidably inserted into the pivoting guide,   wherein the pivoting guide has a straight line shape and the second connecting unit moves back and forth in a straight line in the pivoting guide and the first connecting unit moves back and forth in a straight line in the movable shaft guide according to the straight-line back-and-forth movement of the second connecting unit.