| 摘要 |
Apparatus for securing an opening vent frame 3 relative to a surrounding fixed frame 14 comprises a keeper 13 mounted on a side edge of the fixed frame 14 and a lock plate 8 housed in a casing 2 mounted on the opposed side edge of the vent frame 3. The plate 8 is moved from a retracted position to an extended position by rotation of an operating handle 10 to engage a leading edge 33 under a selected one of two elongate projections 31a,31b of the keeper 13 in partially open or closed positions of the vent frame 3. Simultaneously, the plate 8 is rotated about an axis normal to the rotational axis of the handle 10 to displace the leading edge 33 towards the outer face 7 of the vent frame 3 so that the vent frame 3 is moved inwards by the engagement of the leading edge 33 with the projection 31a,31b. <IMAGE> |
