Restrictor device with a releasable latch member

In a window construction comprising a window sash movably located within a window frame wherein a cavity is formed between said sash and frame when the sash is in the closed position, a restrictor device for restricting the extent of opening movement of the sash, the restrictor device being located within the cavity and comprising in combination:

• an arm adapted for coupling to one of the closure member or frame,
• latching means adapted for mounting with the other of the frame or closure member,
• a latch element included with said latching means, said latch element coupling said arm to the latching means, said latch element being mounted for movement to a release position to enable the arm to be released from being coupled with the latch element,
• a latch member which is operative such that the latch element can move to said release position,
• operating means associated with said latch member to enable said latch member to be operated, and
• restriction means for preventing said latch element from moving to said release position except when said arm is in a substantially predetermined position relative to said latching means, said operating means having a portion which is accessible externally of the cavity.