Metering Pump with proportional output

Abstract

A metering pump includes an actuating mechanism, and a plurality of piston cylinders coupled to the actuating mechanism. A first of the cylinders has a working volume that differs from a second of the cylinders. The actuating member is centrally located and the cylinders are arranged radially about the actuating mechanism. The working volume of the cylinders can be varied by adjusting the spacing of the cylinders from the actuating mechanism, thus varying the stroke of pistons housed within the cylinders, and/or by providing the cylinders with different inner diameters. A method of metering fluids includes independently adjusting stroke of a plurality of pistons to adjust the volume of metered fluid, and selecting different cylinder diameters to adjust the volume of metered fluid.

1 . A metering pump, comprising: 
 an actuating mechanism, and    a plurality of piston cylinders arranged radially about the actuating mechanism and coupled to the actuating mechanism, a first of the cylinders having a working volume that differs from a second of the cylinders.    
   
   
       2 . The metering pump of  claim 1  further comprising a piston housed within the first cylinder, and a piston housed within the second cylinder, the piston of the first cylinder having a stroke that differs from the piston of the second cylinder.  
   
   
       3 . The metering pump of  claim 2  wherein the first cylinder is spaced from the actuating mechanism a distance that differs from a spacing of the second cylinder from the actuating mechanism.  
   
   
       4 . The metering pump of  claim 3  further comprising an adjustment mechanism configured to vary the spacing of the cylinders from the actuating mechanism.  
   
   
       5 . The metering pump of  claim 4  wherein the cylinders are pivotably connected to a housing and the adjustment mechanism comprises a screw and nut.  
   
   
       6 . The metering pump of  claim 1  wherein the first cylinder has a dimension defining an inner volume that differs from a corresponding dimension of the second cylinder.  
   
   
       7 . The metering pump of  claim 6  wherein the dimension is an inner diameter of the cylinder.  
   
   
       8 . The metering pump of  claim 1  comprising at least three cylinders  
   
   
       9 . The metering pump of  claim 8  wherein each cylinder has a working volume that differs from the other cylinders.  
   
   
       10 . The metering pump of  claim 1  wherein the actuating mechanism comprises a transition arm coupled to a stationary support and a rotary member.  
   
   
       11 . The metering pump of  claim 10  wherein the transition arm is coupled to the stationary support by a U-joint.  
   
   
       12 . The metering pump of  claim 10  wherein the transition arm includes a plurality of drive arms and a plurality of joints, each drive arm being coupling to one of the cylinders by a respective joint.  
   
   
       13 . The metering pump of  claim 12  wherein the joint provides three degrees of freedom.  
   
   
       14 . The metering pump of  claim 13  wherein the joint provides four degrees of freedom.  
   
   
       15 . The metering pump of  claim 1  wherein the actuating mechanism is centrally located.  
   
   
       16 . A metering pump, comprising: 
 a centrally located actuating mechanism including a transition arm coupled to a stationary support and a rotary member, and    a plurality of piston cylinders arranged radially about the actuating mechanism and coupled to the actuating mechanism.    
   
   
       17 . A method of metering fluids, comprising: 
 independently adjusting stroke of a plurality of pistons to adjust the volume of metered fluid, each piston being housed within a cylinder having a fluid inlet and a metered fluid outlet, and    selecting different cylinder diameters to adjust the volume of metered fluid.    
   
   
       18 . The metering pump of  claim 12  wherein the joint comprises: 
 an outer member configured for movement along a first axis, the outer member defining an opening for receiving the drive arm, and    an inner cylindrical member mounted within the outer member for rotation relative to the outer member about the first axis, the inner member being coupled to the outer member for controlled motion along the first axis with the outer member.