Metering Pump

Abstract

A metering pump includes at least a first piston and a second piston which are displaceable in a first cylinder bore and in a second cylinder bore, respectively, the at least two pistons having a common driving device, and the second piston being displaceably connected to and displaced with the first piston for a portion of the stroke length of the first piston.

1 . A metering pump comprising at least a first piston and a second piston which are displaceable in a first cylinder bore and in a second cylinder bore, respectively, the at least two pistons having a common driving device, wherein the second piston is displaceably connected to and is displaced with the first piston for a portion of the stroke length of the first piston. 
     
     
         2 . The metering pump in accordance with  claim 1 , wherein the second piston is moved in a discharge direction by a first spring which is connected to the first piston. 
     
     
         3 . The metering pump in accordance with  claim 1 , wherein the second piston is displaced in an intake direction by a second spring. 
     
     
         4 . The metering pump in accordance with  claim 2 , wherein the first spring is dimensioned to exert a greater force than the second spring. 
     
     
         5 . The metering pump in accordance with  claim 2 , wherein the free length of the first spring restricts the stroke length of the second piston. 
     
     
         6 . The metering pump in accordance with  claim 1 , wherein the stroke length of the second piston is restricted by a stop on the first piston. 
     
     
         7 . The metering pump in accordance with  claim 1 , wherein the stroke length of the first piston is adjustable. 
     
     
         8 . The metering pump in accordance with  claim 1 , wherein the stroke length of the second piston is adjustable. 
     
     
         9 . The metering pump in accordance with  claim 1 , wherein the first piston and the second piston have a common longitudinal axis.