Abstract: A locking hinge assembly for mounting a visor on a helmet includes a cylindrical body which is fixed in an opening in the helmet and is loosely received through an aligned opening in the visor. The body has an annular detent flange with detent recesses therein in which are received detent studs carried by the visor for accommodating movement of the visor among a plurality of discrete detent positions. The locking assembly includes a shaft extending through an axial bore in the body and having an enlarged cam head at the outer end thereof. A cam disk is disposed between the head and the visor and has cam studs which cammingly engage cam recesses in the head. A spring washer is disposed between the cam disk and the visor for urging the detent studs into the recesses to resiliently hold the visor in each detent position and for urging the cam disk against the head.