Metering pump

Abstract

A metering pump is disclosed which has a simple structure and in which conventional injectors can be used as pump elements. Injectors having different piston diameters can be inserted in a clamping means, and due to the arrangement of the elements of the metering pump on a base plate, a simple structure results.

1 . Metering pump, comprising: 
 a base plate,    a clamping means, mounted on the base plate, for clamping injection cylinders of at least two injectors,    two actuating elements which are displaceable on the base plate and to which piston rods of the injectors are connectable,    a control means mounted on the base plate and joined by pipes to the injection cylinders of the injectors, wherein connecting pipes are connectable to the control means, and    a drive means which moves the actuating elements back and forth counter to one another and switches over the control means such that the pipes connected to the injection cylinders are connected to different connecting pipes.    
   
   
       2 . Metering pump according to  claim 1 , wherein the actuating elements are each joined by a clamping jaw to a section of a band which is guided around two rollers and is moved back and forth by a drive motor.  
   
   
       3 . Metering pump according to  claim 1 , wherein the drive means of the actuating elements is joined to a switching means having a switching bracket which is biased in opposite directions by springs, is joined to the control means, and is held by catch elements in end positions in which the switching bracket ( 9 ) is biased by one of the springs.  
   
   
       4 . Metering pump according to  claim 1 , wherein at each of the actuating elements, which are synchronously displaceable relative to one another, a group of injectors is mountable, so that for each stroke movement, simultaneously both groups of injectors carry out an intake stroke or a delivery stroke.  
   
   
       5 . Metering pump according to  claim 4 , wherein the group of injectors are joinable in different ways to the control means, to set a pre-determined volume flow combination.  
   
   
       6 . Metering pump according to  claim 1 , wherein the strength train of the drive means of the injectors is formed rigid and clearance-free.  
   
   
       7 . Metering pump according to  claim 1 , wherein in the control means a de-aerating valve is provided, by means of which the individual injectors can be de-aerated.  
   
   
       8 . Metering pump according to  claim 7 , wherein the pump is positioned in a vertical position on a support (T) such that the pistons of the injectors lie on top, for facilitating de-aeration of the injectors.  
   
   
       9 . Metering pump according to  claim 1 , wherein all the components of the pump which come into contact with medium are made of electrically insulating material or are electrically insulated.  
   
   
       10 . Metering pump according to  claim 1 , wherein the drive motor is formed such that is produces a sine-shaped drive movement.