Bag Lift Assembly for a Lined Bulk Material Container

Abstract

A lifting assembly for a polymeric liner disposed within a fluid material container. The assembly includes a pneumatic linear drive, and, an interface member that is supportively connecting to the polymeric liner. A tension line is coupled between the pneumatic linear drive and the interface member, and a line guide is positioned to route the tension line to a central location above the polymeric liner, and thereby correspondingly locates the interface member. A pneumatic controller actuates the pneumatic linear drive to move in a first direction, to move in a second direction, or to remain in a fixed position. Movement of the pneumatic linear drive in the first direction causes the tension line to lift the interface member in an upward direction, and, movement of the pneumatic linear drive in the second direction causes the tension line to lower the interface member in a downward direction.

What is claimed is: 
     
         1 . A lifting assembly for a polymeric liner disposed within a fluid material container, comprising:
 a pneumatic linear drive;   an interface member adapted for supportive connection to the polymeric liner;   a tension line coupled between said pneumatic linear drive and said interface member;   a line guide positioned to route said tension line to a central location above the polymeric liner, thereby correspondingly locating said interface member;   a pneumatic controller coupled to actuate said pneumatic linear drive to move in a first direction, to move in a second direction, or to remain in a fixed position, and wherein   movement of said pneumatic linear drive in said first direction causes said tension line to lift said interface member in an upward direction, and, movement of said pneumatic linear drive in said second direction causes said tension line to lower said interface member in an downward direction.   
     
     
         2 . The assembly of  claim 1 , and wherein the polymeric liner is a bag structure that includes support fitments, and wherein
 said interface member includes at least a first connector adapted to engage the support fitments.   
     
     
         3 . The assembly of  claim 2 , and wherein the support fitments are selected from a loop of polymeric material, an eyelet inserted through the polymeric material and a reinforced portion, and wherein
 said at least a first connector is selected from a hook, a ring, a karabiner, and a clamp.   
     
     
         4 . The assembly of  claim 1 , and wherein the fluid material container is a rigid structure with an open top, and wherein:
 said interface member is inserted through the open top.   
     
     
         5 . The assembly of  claim 1 , and wherein:
 said pneumatic linear drive is a rodless pneumatic cylinder.   
     
     
         6 . The assembly of  claim 1 , and wherein:
 said interface member is a spider structure with a central joint that is connected to said tension line with spider arms extending outwardly, which are connected to the polymeric liner.   
     
     
         7 . The assembly of  claim 1 , and wherein:
 said tension line is a cable.   
     
     
         8 . The assembly of  claim 1 , and wherein:
 said line guide includes a pulley, around which said tension lines is routed.   
     
     
         9 . The assembly of  claim 1 , further comprising:
 a housing, having said pneumatic linear drive disposed therein, and which is adapted for mounting to the fluid material container.   
     
     
         10 . The assembly of  claim 9 , and wherein:
 said housing comprises a line guide support member, which orients said line guide at said central location above the polymeric liner.   
     
     
         11 . The assembly of  claim 10 , and wherein:
 said line guide support member extends as a cantilever from said housing to said central location.   
     
     
         12 . The assembly of  claim 1 , and wherein:
 said pneumatic controller is a three-position, four-port, pneumatic valve with a closed center position.   
     
     
         13 . The assembly of  claim 1 , and wherein:
 said pneumatic controller is coupled within a pneumatic circuit that has a regulated pressure, and wherein   said pneumatic circuit further include a relief valve set to a pressure less than twenty percent greater than said regulated pressure, thereby limited the maximum force exerted by said pneumatic linear drive.   
     
     
         14 . The assembly of  claim 13 , further comprising:
 a flow control orifice coupled to an exhaust port of said pneumatic controller, thereby controlling the rate of movement of said pneumatic linear drive.