Airflow regulator

Abstract

The invention provides an airflow regulator for a mine passage, comprising: a louver blade pivotable to a predetermined position, which is in a range from a closed position in which the louver blade restricts at least a portion of the passage to an open position in which air is readily able to flow in the passage; and a linkage mechanism for pivoting the louver blade wherein the linkage mechanism includes a biasing strut mechanism which is only activated to pivot the louver blade into the open position when a predetermined airflow is reached and biases the louver blade to its predetermined position after the airflow has reduced to less than the predetermined airflow.

1 . An airflow regulator for a mine passage comprising:
 a louver blade pivotable to a predetermined position which is in a range from a closed position in which the louver blade restricts at least a portion of the passage to an open position in which air is readily able to flow in the passage; and   a linkage mechanism for pivoting the louver blade wherein the linkage mechanism includes a biasing strut mechanism which only activates to pivot the louver blade into the open position when a predetermined airflow is reached and biases the louver blade to its predetermined position after the airflow has reduced to less than the predetermined airflow.   
     
     
         2 . A regulator as defined in  claim 1  which comprises a frame in which the louver blade is mounted. 
     
     
         3 . A regulator as defined in  claim 1  which comprises a plurality of louver blades. 
     
     
         4 . A regulator as defined in  claim 1  wherein the biasing strut mechanism is a constant force biasing strut mechanism which activates when a predetermined constant force has been reached, preferably the biasing strut mechanism is a gas strut. 
     
     
         5 . A regulator as defined in  claim 1  wherein the linkage mechanism includes a linkage bar that is operatively coupled to a louver blade via a linkage arm. 
     
     
         6 . A regulator as defined in  claim 1  wherein the linkage mechanism has a position control mechanism to selectively vary the length of the linkage mechanism, preferably the position control mechanism is a powered actuator. 
     
     
         7 . A regulator as defined in  claim 6  wherein the linkage mechanism includes a linkage bar that is operatively coupled to a louver blade and the biasing strut mechanism is provided between the linkage bar and the position control mechanism. 
     
     
         8 . A louver type airflow regulator for a mine passage comprising:
 a plurality of louver blades mounted in a frame and pivoting therein around a lengthwise axis between a predetermined position in which the louver blades combine to close or restrict at least a portion of the passage, and an open position in which air is readily able to flow between the louver blades and through the passage portion; and   wherein when a predetermined airflow is reached, the louver blades are arranged to open or open further, unless already fully open, and including a return mechanism to cause the blades to return to their predetermined position after the airflow has reduced to less than the predetermined airflow, and   wherein the return mechanism includes a biasing means in the form of a strut mechanism that is operatively connected to a linkage mechanism that acts on one or more of the louver blades to urge them into the predetermined position and wherein the return mechanism is such that the strut mechanism is not activated except when the blades open after the predetermined airflow is reached.   
     
     
         9 . A regulator as defined in  claim 8  wherein the strut mechanism is a gas strut comprising a cylinder, piston and piston rod, preferably a free end of the piston rod is pivotally mounted to means for raising and lowering that end, preferably the means is an externally threaded rod located above a hollow strut and a handle and threaded sleeve, turning the handle raising and lowering the threaded rod. 
     
     
         10 . A regulator as defined in  claim 8  wherein the gas strut is a constant force strut mechanism which only moves/is activated when a force in excess of 4000 Newton is applied to it. 
     
     
         11 . A regulator as defined in  claim 8  wherein the return mechanism includes a vertically oriented linkage bar that is operably coupled to each louver blade via a linkage arm one end of which is fixed to the louver blades and the other end of which is pivotally mounted to the linkage bar. 
     
     
         12 . A regulator as defined in  claim 11  wherein the strut mechanism is a gas strut and wherein one end of the gas strut is pivotally mounted to the linkage bar by a bracket or the like fixed to the bar such that movement of the bar moves that end of the strut. 
     
     
         13 . (canceled) 
     
     
         14 . A method of regulating airflow in a mine passage comprising steps of:
 (a) providing a louver blade, a linkage mechanism for pivoting the louver blade wherein the linkage mechanism includes a biasing strut mechanism which acts on the louver blade;   (b) pivoting the louver blade to a predetermined position which is in a range from a closed position in which the louver blade restricts at least a portion of the passage to an open position in which air is readily able to flow in the passage;   (c) adjusting the biasing strut mechanism to activate to pivot the louver blade into the open position when a predetermined airflow is reached and to bias the louver blade to its predetermined position after the airflow has reduced to less than the predetermined airflow.   
     
     
         15 . A method as defined in  claim 14  wherein step (a) comprises providing a frame in which the louver blade is mounted. 
     
     
         16 . A method as defined in  claim 14  wherein step (a) comprises providing a plurality of louver blades. 
     
     
         17 . A method as defined in  claim 14  wherein the biasing strut mechanism is a constant force biasing strut mechanism which activates when a predetermined constant force has been reached, preferably the biasing strut mechanism is a gas strut. 
     
     
         18 . A method as defined in  claim 14  wherein the linkage mechanism includes a linkage bar that is operatively coupled to a louver blade via a linkage arm. 
     
     
         19 . A method as defined in  claim 14  wherein the linkage mechanism has a position control mechanism to selectively vary the length of the linkage mechanism, preferably the position control mechanism is a powered actuator. 
     
     
         20 . A method as defined in  claim 19  wherein the linkage mechanism includes a linkage bar that is operatively coupled to a louver blade and the biasing strut mechanism is provided between the linkage bar and the position control mechanism.