| 摘要 |
A fire collar, for location in a concrete slab around a deformable conduit, has a housing with a passageway through which the conduit passes. The collar has the housing in which are located two compression springs with arms which are held against the force of the springs by fusible links. When the heat of a fire on one side of the slab causes the fusible links to soften or melt, the force of the springs causes the spring arms to rotate towards the conduit, engaging the conduit and collapsing it. An intumescent layer may be provided around the conduit to assist in collapsing it. |
