Window opening mechanism

A sash and case window comprising a case containing a top sash and a bottom sash which operate vertically therein, the top sash being outward of the bottom sash and the bottom sash being rotatable inwardly from a normal position thereof on first hinging means provided therefor, second hinging means being provided on which the top sash is rotatable inwardly from a normal position thereof, wherein the top and bottom sashes are separated by at least one parting bead forming part of the case, and said second hinging means is mounted in a said parting bead and comprises at least one hinge comprising a support arm that is mounted in said parting bead of the case, that is moveable from a substantially vertical retracted position to a first substantially horizontal deployed position, and that carries at a free end thereof a hinge pin for engagement with a complementary anchor fitting mounted on the top sash, said anchor fitting having an opening therein formed and arranged for complementary engagement with the hinge pin of a respective support arm, and wherein each said support arm is rotatable between said retracted and deployed positions and each said anchor fitting on the top sash comprises a housing recessed in the top sash and a hinged portion which is rotatable from a substantially vertical retracted position, in which it is contained in said housing, to a second substantially horizontal deployed position for the complementary engagement with said hinge pin of the respective support arm when it is in the second substantially horizontal deployed position.