Lockable latch for tiltable double hung windows

Claim 1

A lockable latch for a pivotable double hung window, comprising: a mountable shell of generally rectangular configuration having a facing wall, a pair of side walls, a rear end wall, an open back and an open front end wall, said shell having an elongated opening near the center thereof extending through said facing wall, and a pair of cylindrical formations extending generally the thickness of said shell from said facing wall with openings therethrough for attaching screws or the like; a slidable latching member received within said shell and having a nose normally projecting through the open front end wall of said shell, said latching member having a pair of elongated slots through which said cylindrical formations of said shell project in sliding relationship, said latching member having a circular recess in its bottom surface; and a locking element comprising a circular base received in said circular recess of said latching member, a post extending upwardly from said circular base and extending through said latching member, and an elongated finger activatable control element extending perpendicularly from said post, said locking element being rotatable between an unlocked position wherein the length of said control element is perpendicular to the length of said latching member, to a locking position wherein the length of said control element is aligned with the length of said latching member wherein an end of said control element abuts against a wall of said shell defining the elongated central opening of said shell, thereby preventing sliding motion between said latching member and said shell and maintaining the nose of said latching member projecting through the front end wall opening of said shell.