Lock

A lock for a wing movable between respective open and closed positions relative to a frame, the lock comprising a casing having an open end and an integral flange adapted to be received, in use, in a rebate in an edge surface of the wing and securable thereto by fixing means received through said flange, a bolt operable to extend from or to retract into said casing, an operating handle pivotally mounted to the casing at one side of the wing for movement from a rest position, to which it is biased, to an operated position normally to effect retraction of said bolt, a casing interior portion with an aperture therethrough to receive fixing means, a closure plate within the casing, spaced from said open end thereof and being secured to the casing solely by respective fixing means passing through said plate to engage with respective fixing members in the casing, a mounting plate for mounting to the wing, in use, the casing with its closure plate secured thereto, the mounting plate being disposed, in use, outwardly of said closure plate, at said open end of the casing with at least one tag of the mounting plate extending through said closure plate and being secured to said casing by fixing means extending through the at least one tag, the casing being further secured to the wing, in use, by fixing means passing through said aperture and said mounting plate into said wing, access for an implement to fasten or release said fixing means being through an opening in said casing, which opening is blocked by the operating handle, thereby to prevent such access, when the operating handle is in its rest position, such access being possible only when the operating handle is in its operated position, such access being through an opening in the pivotal operating handle.