Toothed-belt fastening, in particular for chin-straps of helmets, protective headgear and the like

Abstract

A toothed-belt fastening, in particular for chin-straps of helmets, protective headgear and the like, comprises a base on which the toothed belt can be slidably engaged, a first and a second pawl which are mounted in an oscillating manner on the base and can in turn be engaged with a toothing of the belt. The first pawl forms a member for unidirectionally locking the toothed belt with respect to the base and is disengageable from the toothing so as to slacken the fastening, while the second pawl is engageable with the toothing so as to tension the fastening and is hinged on the base coaxially with the first pawl.

1 . Toothed-belt fastening, in particular for chin-straps of helmets, protective headgear and the like, comprising a base with which said toothed belt can be slidably engaged, a first and a second pawl which are mounted in an oscillating manner on the base and can in turn be engaged with a toothing of said belt, said first pawl forming a member for unidirectionally locking the toothed belt with respect to the base and being disengageable from the toothing so as to slacken said fastening, said second pawl being engageable with the toothing so as to tension said fastening, characterized in that said pawls are hinged coaxially on said base.  
     
     
         2 . Fastening according to  claim 1 , in which both said pawls are pivotably mounted on the same pin.  
     
     
         3 . Fastening according to  claim 2 , in which both said pawls have operating lugs co-extending on the same side with respect to said pin.  
     
     
         4 . Fastening according to  claim 2  or  3 , in which said first pawl has a pair of spaced tines by means of which it is hinged with said pin, said second pawl being hinged with said pin between said tines.  
     
     
         5 . Fastening according to one or more of the preceding claims, in which both said pawls and associated operating lugs have a unitary structure.  
     
     
         6 . Fastening according to  claim 5 , in which said operating lugs of said pawls are normally arranged superimposed on each other.  
     
     
         7 . Fastening according to one or more of the preceding claims, in which said first pawl is resiliently biased into engagement with said toothing by first resilient means active between the latter and said base, said second pawl being biased into disengagement from said toothing by second resilient means active between the latter and said first pawl.  
     
     
         8 . Fastening according to  claim 7 , in which said second resilient means have a constant elasticity smaller than that of said first resilient means.  
     
     
         9 . Fastening according to one or more of the preceding claims, in which said first pawl can be oscillated in a limited manner with respect to said base such that, within the oscillation limits of said first pawl, said second pawl is disengaged from said toothing.  
     
     
         10 . Fastening according to one or more of  claims 2  to  9 , in which said second pawl is hinged in a displaceable manner on said pin.