| 摘要 |
<p>An alarm device (112) capable of emitting alarm signals is incorporated in the frame of a window or a door and cooperates with a magnet or other device (115) incorporated in the end of the hinge of the window. The alarm device (112) is completely concealed and contained in the window frame when the window is closed. As the window opens the device (112) comes out of the field of the magnet (115) and thus sets off the alarm.</p> |
