| 摘要 |
1,066,484. Minimizing spread of fires. COLT VENTILATION & HEATING Ltd. Oct. 19, 1964 [Oct. 24, 1963], No. 42069/63. Heading A5A. [Also in Division F4] A wall vent to be opened manually or automatically in the event of fire comprises a shutter 21 pivoted about its lower edge to a frame 18, the shutter normally being held closed by a pneumatic piston and cylinder 23 against a bias tending to open the shutter. As illustrated the bias is provided by torsion springs 50. In the event of fire, air pressure to the cylinder is cut off and the shutter opens, the piston and cylinder 23 pivoting and extending to determine the limit to which the shutter opens. When the shutter is closed, the piston and cylinder are enclosed within interengaging channel members 44 and 43 attached to the frame and shutter respectively. In modifications (not shown) the opening bias may be provided by a weight linked to the shutter, or the shutter may be arranged to tend to open by virtue of its own weight. |
