Air vent closure system

Abstract

An automatic ventilator closure is described which operates on the basis of an over-pressure within the conduit leading up to the ventilator outlet. Electrical interlocks control a motor to place the closure in an open or closed condition.

The embodiments of the invention in which an exclusive property is claimed as follows: 
     
       1. A closure means on an outlet for a forced air exhaust conduit which is positioned to convey air from within a closed structure to a region exterior to such structure, comprising: (1) an actuating motor means for positioning said closure in either a closed or open state in response to electrical current provided by an electrical source;   (2) electrical switch means for providing said motor with said electrical current;   (3) an over-pressure sensor system responsive to an over-pressure condition in said conduit with respect to ambient pressure external to said conduit and connected to activate said switch, . .such sensor system comprising:   (a) a bleed-outlet formed in said conduit through which air tends to escape when said over-pressure condition exists; and   (b) a pressure-sensing means positioned to swing between a first, over-pressure detecting position closing said bleed-outlet, and a second, no-pressure detecting position where said bleed-outlet is not closed.!..Iadd.; and   (4) an air flow sensing means which is positioned to detect the presence or absence of air flow within said conduit.Iaddend., wherein said electrical switch is activated by said . .pressure sensing means.!. .Iadd.over-pressure sensor system and by said air flow sensing means in parallel .Iaddend.to control said motor means .Iadd.to open said closure in the presence of either airflow or an over-pressure condition and to close said closure in the absence of both air flow and an over-pressure condition.Iaddend..     
     
     
       2. A closure means as in claim 1 wherein said . .electrical switch means is also activated in parallel by an air flow sensing means which is positioned to detect the presence or absence of air flow within said conduit.!..Iadd.over-pressure sensor system comprises: (a) a bleed-outlet formed in said conduit through which air tends to escape when said over-pressure condition exists; and   (b) a pressure-sensing means positioned to swing between a first over-pressure detecting position closing said bleed-outlet, and a second, non-pressure detecting position where said bleed-outlet is not closed.Iaddend..   
     
     
       3. A closure means as in claim 1 or 2 wherein first electrical interlock and switching means is provided to interrupt the flow of current to said motor when said closure means is in a fully open position, and to permit the flow of current to said motor, in a direction so as to effect closure of said conduit, when said pressure sensing means is at said no-pressure position. 
     
     
       4. A closure as in claim 3 wherein a second interlock and switching means is provided to interrupt the flow of current to said motor, once the closure means on the conduit is in a fully closed condition, and to permit current to flow to said motor means, in a closure-opening direction, once the pressure-sensing means is activated by an over-pressure condition in said conduit. 
     
     
       5. A closure means as in claim . .1 or.!. 2 wherein a secondary bleed-outlet closure means is provided which is positioned to close said bleed-outlet when an over-pressure condition does not exist within said conduit. 
     
     
       6. A closure means as in claim 4 wherein a secondary bleed-outlet closure means is provided which is positioned to close said bleed-outlet when an over-pressure condition does not exist within said conduit. 
     
     
       7. A closure as in claims 1 or 2 in the form of a modular unit incorporating a battery as said electrical source that may be fitted at the exiting end of said . .closure.!. .Iadd.conduit. .Iaddend. 
     
     
       8. A closure as in claim 3 in the form of a modular unit, incorporating a battery as said electrical source, that may be fitted at the exiting end of said . .closure.!. .Iadd.conduit. .Iaddend. 
     
     
       9. A closure as in claim 4 in the form of a modular unit, incorporating a battery as said electrical source, that may be fitted at the exiting end of said . .closure.!. .Iadd.conduit. .Iaddend. 
     
     
       10. A closure as in claim 5 in the form of a modular unit, incorporating a battery as said electrical source, that may be fitted at the exiting end of said . .closure.!. .Iadd.conduit. .Iaddend. 
     
     
       11. A closure as in claim 6 in the form of a modular unit, incorporating a battery as said electrical source, that may be fitted at the exiting end of said . .closure.!. .Iadd.conduit. .Iaddend.