| 摘要 |
A vent security device 21 comprises a mounting plate 23 for attachment to a first part of a window frame 25 and a tapered projection 29 for engaging a second part of the window frame 39, wherein the projection 29 and the mounting plate 23 are articulated. A leaf spring (not shown) acts between the projection and mounting plate so that the projection approaches an aperture 49 in a keep 37 at the correct angle to facilitate entry. The aperture has a chamfered edge 51 for receiving the projection. As a result, the security device can be used with an egress hinge (not shown) in which the angle of approach of the moveable frame 25 towards the fixed frame 39 is severe. |
