摘要 |
A smoke and heat release roof hatch (1) has a spring-operated lever arm pushrod (7) mechanism that pivots (Po) the hatch (1) to open over a turret outlet (15). The pushrod is attached to a supporting lever (10) that swings thru a second pivot axis (P3). The two pivot points (Po, P3) are spaced apart. One end of a supplementary lever (11) is attached to the pushrod (7). One end of a tensile spring (14) is attached (17) to the turret (15) at a point that is further from the first pivot point (Po) than the drive (7) swivel axis (P2). The other end of the spring (14) is attached to the lower part (9) of the pushrod (7). |