| 摘要 |
<p>A sliding fire door (50) comprising: a door panel (32) that can move both ways along a guideway (12) horizontal and parallel to the plane of the door panel (32) between a closed position and a maximum opening position, two or more suspension rollers (14) facilitating the movement of the door panel (32) along the guideway (12), stored-energy closure means (11) that move the door panel (32) to the closed position when it is left open and means of constraint (10.1; 10.2) that hold the door panel (32) in an open position if subjected to temperatures below a set value. The means of constraint (10.1; 10.2) are independent of the closure means (11) and comprise: at least one kinematic mechanism (25; 35) cooperating with at least one roller (14) also carried by the door panel (32) and able to roll along a guidesurface (12) following the movement of the door panel (32), the kinematic mechanism (25; 35) being in one of two conditions, a first condition in which rotation of the roller (14) or rollers cooperating with it is only blocked in the direction of rotation corresponding to the closing movement of the door panel (32), thereby generating sliding friction between this roller (14) or these rollers and the respective guidesurface (12) that is able to overcome the action exerted on the door panel (32) by the closure means (11) and a second condition in which the said roller (14) or said rollers are free to rotate in both directions, and electromagnetic means (31; 51) that, when electrically powered, act on the kinematic mechanism (25; 35) to keep it in its first condition, whilst when the power supply is interrupted, in particular following detection of a fire, their action on the kinematic mechanism (25; 35) ceases, the latter consequently finding itself in its second condition, so that the door closes under the action of the closure means (11).</p> |
