Sound deafening grid for ventilation duct - has members resiliently suspended by vertical rods, wires or strips

摘要

A sound deadening member for installation in groups is a duct or wall opening for e.g. air conditioning equipment may be of aerofoil or tubular shape, with double walls of sound deadening material having different values of frictional resistance, operating on the relaxation principal, and attached by upper and lower clips to a vertical wire, rod or strip secured to the top and bottom of the duct, e.g. at both ends of the member. The vertical rod may be attached by spring strips with adjusting screws top and bottom. Alternative designs include shaped metal diaphragms.