| 摘要 |
<p>A security device permitting an inwardly-openable door to be partly opened and to be held by the security device, when operative, from further opening movement. The security device includes a latch mounted on the inside of the door, a retractable bolt, and an arm mounted on a frame member for pivoting about an axis normal to the axis of pivoting of the door. The arm is of hollow box-like construction and has a front wall provided with a slot with which the bolt is engaged. The bolt has a transverse groove in which the edge of the slot is received, the groove is slidable along the edge of the slot and engaged thereby to prevent withdrawal of the bolt from the slot as the door is opened. The slot has at least one end portion from which the groove in the bolt is disengaged when further opening of the door is to be permitted.</p> |
