Lockable push-to-release door or window fastener with a handle and snap-action spring biased latch with cam

A push-to-release fastener for a door or window comprising a handle 1 pivotably mounted 3,4 on a backplate 2 and a cylindrical latching member 11 mounted for displacement between a downward release position and an upper latching position in which a full-section portion 41 of the latching member 11 is positioned within a single recess 29 of the backplate 2 to resist turning of the handle 1. The latching member 11 has a single camming surface 34 for moving the latching member towards its downward release position during pivoting movement of the handle from its free position towards and into its retaining position. The single camming surface 34 engages against a cooperating camming surface 38 of the backplate 2 bordering the single recess 29 of the backplate 2. The latching member 11 is restored to its latching position by the action of a spring 12 on alignment of the latching member portion 41 with the recess 29 and is displaced into its downwards position to release the fastener by manual depression on the upper end of barrel 23. The recess 29 may open away from the handle pivot, or towards it as in the embodiment of Figs 11-16. A lip 32 located below flange 28 of the backplate 2 prevents the handle 1 being upwardly prised open.