GB625798A - Louver mechanism for attic ventilation - Google Patents

Abstract

625,798. Ventilators. MADER, E. A., and SPARGO, J. July 10, 1947, No. 18319. Convention date, May 20, 1940. [Class 137] [Also in Group XXI] Louvres 2 spanning an opening for the upflow of air are actuated in unison by a link bar 7 connected to the free ends of the louvres by brackets 8, the other ends being pivoted on rods 3 journalled on opposite sides of the opening frame 1. A rock shaft 9 of inverted V shape is also pivoted on opposite sides of the frame above the link bar in its raised position and connected to it through a plate 12 fixed to the apex of the shaft and a link 11, plate 12 also being connected through a fusible link 13 to a spring 14 anchored at its other end to a post 15 so that the pull of the spring is applied upwardly to the closed louvres. The spring tension which may be adjusted by means of a nut 17 on the securing bolt 16 is arranged so to balance the louvres as to allow of their opening under a moderate air pressure. In one modification, an inverted L-shaped member replaces plate 12 and has a weighted upper arm and a lower arm normally maintained by the spring out of alignment with a link connecting it with the link bar but caused to align with it on severance of the fusible link, the louvres which then fall under their own weight thus being locked. In another, the link bar is suspended from a cable passing over a pulley mounted near the free end of an arm pivoted to a post at the end of the frame to a spring anchored to the post, the arm itself being supported from the post by a spring connected through a fusible link to the free end of the arm. This carries a short downward projection which, when the link fuses and the arm falls, seats itself on a louvre and secures it against opening. '