Window tilt latch

2- An interlock device according to claim 1, wherein said protruding jamb-engagement portion comprises a hook element.

3- An interlock device according to claim 2, wherein said hook element has a curved surface shaped to hook around a portion of said jamb liner.

4- An interlock device according to claim 1, further including a housing which encloses at least portions of said latch member.

5- An interlock device according to claim 4, including a resilient biasing element operably disposed between said housing and said latch member to urge the latch member toward said jamb liner.

6- An interlock device according to claim 1, including a finger grip on said latch member to facilitate manual movement of said member toward or away from said jamb liner.

7- An interlock device according to claim 6, wherein said protruding jamb-engagement portion comprises a hook element.

8- An interlock device according to claim 7, wherein said hook element has a curved surface shaped to hook around a portion of said jamb liner.

9- An interlock device according to claim 7, further including a housing which encloses at least portions of said latch member.

10- An interlock device according to claim 9, including a resilient biasing element operably disposed between said housing and said latch member to urge the latch member toward said jamb liner.

12- An interlock device according to claim 11, including a resilient biasing member acting on said latch member to urge it in one direction of its pivotal movement.

13- An interlock device according to claim 12, wherein said mounting portion of said latch member comprises a part of said pivot mount structure.

14- An interlock device according to claim 13, wherein said housing has an internal hub providing a pivot mount and said mounting portion of said latch member comprises a recess which pivotally receives said pivot mount.

15- An interlock device according to claim 11, wherein said resilient biasing member is disposed inside said housing.

16- An interlock device according to claim 15, wherein said resilient biasing member comprises a spring.

17- An interlock device according to claim 11, wherein said latch member has a finger grip/thumb latch which is manually accessible from outside said housing.

18- In combination, a window sash having oppositely disposed sides slidably mounted between a pair of spaced jamb liners, and an interlock device for retaining said sash in place as so mounted, said sash member having a top rail extending between said sides, and said interlock device mounted on said top rail generally adjacent one of said jamb liners;

• said interlock device having a latch member mounted for pivotal movement toward and away from said generally adjacent jamb liner and said latch member having a projecting interlock portion which is movable into engagement with said jamb liner upon pivotal movement of said latch member toward said jamb liner, said engagement securing said sash to said jamb liner to retain the sash in mounted engagement with respect to the jamb liner, and said latch member being slidable along the jamb liner while so engaged with it to permit sliding movement of the sash along the jamb liner with the latch member and jamb liner so engaged.

19- The combination recited in claim 18, wherein said jamb liner includes a ridged portion extending along its length and positioned to enable at least part of said projecting interlock portion of said latch member to enhance secure interengagement of said latch member and jamb liner.

20- The combination recited in claim 19, wherein said latch member is at least partially enclosed within a housing.