Ventilation device

Abstract

A device is described for controlling the airflow through an airduct, the airduct having a housing, an inlet and an outlet. The device comprises a self-regulating valve having a diaphragm, the position of the diaphragm being determined by the difference between the pressure at the inlet and the pressure at the outlet. The diaphragm is rotatably suspended on a support so that, under influence of an increasing difference in pressure, the diaphragm can rotate between a minimum rotation angle and a maximum rotation angle over an intermediate rotation angle, the intermediate angle being situated between the minimum and maximum angle. The diaphragm is provided with a counterbalance and that, within the angle range between the intermediate rotation angle and the maximum rotation angle, the rotation movement of the diaphragm under influence of an increasing pressure difference is counteracted by an elastic resisting force.

1 . Device for controlling the airflow through an airduct, the airduct having a housing, an inlet and an outlet, the device comprising
 a self-regulating valve having a diaphragm, the position of the diaphragm being determined by the difference between the pressure at the inlet and the pressure at the outlet   the self-regulating valve being rotatably located on a support so that, under influence of an increasing difference in pressure, the diaphragm can rotate between a minimum rotation angle and a maximum rotation angle over an intermediate rotation angle, the intermediate angle being situated between the minimum and maximum angle,   wherein the valve is provided with a counterbalance and wherein,   within the angle range between the intermediate rotation angle and the maximum rotation angle, the rotation movement of the valve under influence of an increasing pressure difference is counteracted by an elastic resisting force, and   wherein the elastic resisting force is generated by contact between a part of the housing and a resilient means which forms part of, or is mounted to the counterbalance or diaphragm and wherein the resilient means comprises a part of the counterbalance or diaphragm which is formed from a resilient material.   
   
   
       2 . The device of  claim 1 , wherein the support is a hinge. 
   
   
       3 . The device of  claim 1 , wherein the elastic resisting force is generated by contact between said counterbalance, or said diaphragm, and the resilient means. 
   
   
       4 . The device of  claim 3  wherein the resilient means are attached to, or form part of, the housing. 
   
   
       5 . The device according to  claim 1 , wherein the resilient means provides substantially constant performance over a temperature range of −20° C. to +40° C. 
   
   
       6 . The device according to  claim 5 , wherein the substantially constant performance of the resilient means is a change of less than 20% in spring constant over the temperature range of −20° C. to +40° C. or 0° C. to 35° C. 
   
   
       7 . The device according to  claim 1 , wherein the resilient means are formed of metal. 
   
   
       8 . The device according to  claim 1 , wherein the counterbalance is dimensioned so as to keep the diaphragm at the minimum rotation angle when the pressure difference has a low or zero value. 
   
   
       9 . The device according to  claim 1 , wherein the flow characteristic of the valve is non-linear and self-limiting. 
   
   
       10 . The device according to  claim 1 , wherein the flow rate through the device remains substantially in a range defined by between 4 and 7 litres/s over a pressure range of 2 to 25 Pa. 
   
   
       11 . The device according to  claim 1  wherein the flow rate through the device varies by less than ±60%, less than ±50% or less than ±40% over a pressure drop range ratio of 5:1, or 10:1. 
   
   
       12 . Device for controlling the airflow through an airduct, the airduct having a housing, an inlet and an outlet, the device comprising
 a self-regulating valve having a diaphragm, the position of the diaphragm being determined by the difference between the pressure at the inlet and the pressure at the outlet   the self-regulating valve being rotatably located on a support so that, under influence of an increasing difference in pressure, the diaphragm rotates between a minimum rotation angle and a maximum rotation angle over an intermediate rotation angle, the intermediate angle being situated between the minimum and maximum angle,   wherein the valve is provided with a counterbalance and wherein,   within the angle range between the intermediate rotation angle and the maximum rotation angle, the rotation movement of the valve under influence of an increasing pressure difference is counteracted by an elastic resisting force,   wherein the elastic resisting force is generated by contact between a part of the housing and a spring which forms part of, or is mounted to the counterbalance or diaphragm, and   wherein the spring comprises a part of the counterbalance or diaphragm which is formed from a resilient material.   
   
   
       13 . The device of  claim 12 , wherein the support is a hinge. 
   
   
       14 . The device of  claim 12 , wherein the elastic resisting force is generated by contact between said counterbalance, or said diaphragm, and the spring. 
   
   
       15 . The device of  claim 14  wherein the spring is attached to, or forms part of, the housing. 
   
   
       16 . The device according to  claim 12 , wherein the spring provides substantially constant performance over a temperature range of −20° C. to +40° C. 
   
   
       17 . The device according to  claim 16 , wherein the substantially constant performance of the spring is a change of less than 20% in spring constant over the temperature range of −20° C. to +40° C. or 0° C. to 35° C. 
   
   
       18 . The device according to  claim 12 , wherein the spring is formed of metal. 
   
   
       19 . The device according to  claim 12 , wherein the counterbalance is dimensioned so as to keep the diaphragm at the minimum rotation angle when the pressure difference has a low or zero value. 
   
   
       20 . The device according to  claim 12 , wherein the flow characteristic of the valve is non-linear and self-limiting.