| 摘要 |
A barrier comprising a roller, a curtain 2, a bottom bar and a friction brake. The curtain arrangement 1 includes a curtain 2, which when not deployed is wound on a roller 4. The roller is provided within a headbox 6, in a ceiling 8. The curtain is provided with a bottom bar 10 which weighs the curtain for descent, but can also be used to close the headbox when the curtain is retracted onto the roller. Side guides 12 are also provided to contain side edges 14 of the curtain. They extend from the headbox 6 on the ceiling to the floor 18. The curtain is held in its retracted position on the roller, by a fusible link 20. An extension 22 of the roller 2 is provided extending out of the headbox 6. The fusible link 20 is provided between the outside of the headbox and the extension 22 of the roller. A peg 24 mounted on the headbox 6 holds one portion 26 of the fusible link, while the other portion 28 of the fusible link is connected to the extension. These portions are held together by a material 30 having a low melting point range typically between 57-150°C. This acts to hold the curtain on the roller under normal condition, preventing rotation of the roller within the headbox, but on sufficient temperature rise, the material 30 will melt, releasing the portions 26, 28 of the fusible link, allowing rotation of the roller and deployment of the curtain. |
