Supporting structure of chin-ventilation shutter for full-face type helmet

Abstract

To increase the amount of open air's introduction, have satisfactory good design and operability, and further increase the degree of freedom of designing a helmet. Two center points for turning are provided for opening and closing a chin-ventilation shutter and the aforementioned center points are capable of being switched on the way to which the closing condition of the chin-ventilation shutter is turned to the opening condition thereof.

What is claimed is:  
     
         1 . A supporting structure for supporting by rotating a mouth shutter for opening and closing ventilation hole formed in a chin guard of a full-face type helmet for a chin-ventilation shutter supporting part fixed to a helmet, wherein: 
 two or more turning center points for opening and closing said chin-ventilation shutter are provided and said turning center points are switched on a way to which a closing condition of said chin-ventilation shutter is turned to an opening condition.    
     
     
         2 . A supporting structure according to  claim 1 , comprising: 
 a chin-ventilation shutter supporting part fixed to a shell side;    a first guide shaft and a second guide shaft for guiding turning in any one side of a chin-ventilation shutter being supported in a rotatable way;    an engaging part being formed by plural arc shapes in accordance with  2  guide axes on another side, wherein:    said first engaging part and said second engaging part formed continuously thereto for said first guide shaft and a third engaging part for said second guide shaft are engaged and included respectively in a movable way,    said first guide shaft and said second guide shaft are guided by said first engaging part and said third engaging part respectively at a first stage of opening said chin-ventilation shutter and turning is made about a first central point being a common center of an arc which both engaging parts have, and    a turning center is switched to a second central point which said second engaging part has from said first central point at a time that said first guide shaft reaches at a connecting point of said first engaging part and said second engaging part and rotates about said second guide shaft on a way to an opening operation.    
     
     
         3 . A supporting structure according to  claim 2 , wherein: 
 said first engaging part and said second engaging part to which said first guide shaft engages in a movable way and said third engaging part to which said second guide shaft engages in a movable way are formed in a grooved shape, and    a step is provided in said second engaging part and said third engaging part formed in a grooved shape and a crossing portion of both engaging portions is also formed in order for each axis not to escape to another engaging part.