US Patent 7051888 Hinged closure device and a container

A closure device comprising a plastic lid which is articulated to a skirt that is designed to surround a neck of a container. A majority of the surface of the lid is made up of an external convex surface that is provided with a concave recess which is disposed more or less opposite an area in which the lid is articulated to the skirt. One section of the lid can rest against a heel which is provided close to an upper edge of the skirt so as to lock the lid in a position in which the device is completely open.