Flush lock for casement window

摘要

A low profile actuating window lock for casement windows having a handle actuate a lifter that slides vertically on a fork component in slidable communication with the window lock casing, the handle pivotable about the lifter and pivotable about a restrictor arm that pivots relative to the casing, allowing the handle to rotate fully from the locked position to the unlocked position with low clearance from the window frame. The pivot points of the handle, lifter, restrictor arm configuration allow for an over center linkage that prevents back driving the casement window lock.

主权项

1. A casement window lock for securing a window sash to a casement window frame, said lock comprising:
an elongated casing having a substantially horizontal sidewall section and a vertical section shorter in length than said sidewall section; a fork component adapted to engage a lock bar external to said lock, said fork component in slidable communication with said casing; a lifter in slidable communication with said fork component; a restrictor arm pivotally attached to said casing; a plurality of hinges or pivot point forming an over center linkage to prevent back driving said lock, wherein said over center linkage includes: a first hinge point rotatably joining said handle to said lifter; a second hinge point rotatably joining said restrictor arm to said casing; and a third hinge point rotatably joining said restrictor arm to said casing; and such that when said handle is in an unlocked position, said first hinge point is between said second and third hinge points, and said second hinge point is in said locked position, said second hinge point is between said first and third hinge points, and said second hinge point is below an action line connecting said first and third hinge points; a handle pivotally attached at one end to said lifter, and pivotally attached at an intermediate point on said handle to said restrictor arm; and wherein upon rotation said handle engages said lifter to move said fork component horizontally along said casing horizontal sidewall section while simultaneously lifting or lowering said lifter relative to said fork component.