Method of filling containers with gases

Abstract

A method of filling containers ( 50 ) with gases ( 12 ) provides each container, when filled, with a first predetermined amount of a first gas and a second predetermined amount of a second gas. The method comprises the step of forming a mixture comprising first and second amounts of the first and second gases, respectively. The first and second amounts are greater than and are in proportion to the first and second predetermined amounts, respectively. The method further comprises the steps of: determining a sum of the first and second predetermined amounts; and adding a third amount of the mixture to each of the containers. The third amount is equal to the sum of the first and second predetermined amounts.

1 . A method of filling containers with gases, each container, when filled, including a first predetermined amount of a first gas and a second predetermined amount of a second gas, the method comprising the steps of:
 forming a mixture comprising first and second amounts of the first and second gases, respectively, the first and second amounts being greater than and in proportion to the first and second predetermined amounts, respectively;   determining a sum of the first and second predetermined amounts; and   adding a third amount of the mixture to each of the containers, the third amount being equal to the sum of the first and second predetermined amounts.   
   
   
       2 . The method of  claim 1  wherein the step of forming a mixture further includes the steps of:
 determining a ratio of the first predetermined amount to the second predetermined amount;   adding the first amount of the first gas to a mixing vessel;   determining the second amount of the second gas to be added to the mixing vessel so that the ratio of the first amount to the second amount equals the determined ratio of the first predetermined amount to the second predetermined amount; and   adding the determined second amount of the second gas to the mixing vessel.   
   
   
       3 . The method of  claim 1  wherein the step of adding a third amount of the mixture to each of the containers further includes the steps of:
 adding mixture to a first container;   determining the amount of mixture added to the first container;   comparing the determined amount of mixture added to the third amount; and   adjusting the amount of mixture added when the determined amount of mixture added is outside of a predetermined tolerance relative to the third amount.   
   
   
       4 . The method of  claim 3  wherein the step of determining the amount of mixture added to the first container includes the steps of:
 determining a mass of the first container when empty;   determining a mass of the first container after the mixture has been added; and   subtracting the determined mass of the first container when empty from the determined mass of the first container after the mixture has been added.   
   
   
       5 . The method of  claim 3  further including the steps of:
 replacing the first container with a second container when the determined amount of mixture added to the first container is within the predetermined tolerance;   adding mixture to the second container;   determining the amount of mixture added to the second container;   comparing the determined amount of mixture added to the second container to the third amount; and   adjusting the amount of mixture added to the second container when the determined amount of mixture added is outside of the predetermined tolerance relative to the third amount.   
   
   
       6 . The method of  claim 5  further including the step of determining, prior to replacing the first container with the second container, whether an amount of mixture remaining is greater than the sum of the first and second predetermined amounts. 
   
   
       7 . The method of  claim 1  further including the step of adding a third gas to each of the containers after the third amount of the mixture has been added. 
   
   
       8 . The method of  claim 7  wherein the step of adding a third gas to each of the containers includes the step of increasing a pressure of the gases in gas storage chambers of each of the containers to a predetermined pressure. 
   
   
       9 . The method of  claim 7  further including the step of closing a fill port of each of the containers after the third gas has been added. 
   
   
       10 . A method of filling inflators with gases, each inflator, when filled, including a first predetermined amount of a first gas and a second predetermined amount of a second gas and being actuatable for inflating an inflatable safety device of a vehicle safety system, the method comprising the steps of:
 forming, in a mixing vessel, a mixture comprising first and second amounts of the first and second gases, respectively, wherein a ratio of the first amount to the second amount equals a ratio of the first predetermined amount of the first gas to the second predetermined amount of the second gas;   determining a sum of the first and second predetermined amounts; and   adding a third amount of the mixture to each of the inflators, the third amount being equal to the sum of the first and second predetermined amounts.