Metering Pump

Abstract

A fluid metering pump is provided having reciprocating pumps including a first fluid displacer and a second reciprocating pump include a second fluid displacer. A transmission and stroke adjuster assembly for couples a prime mover to each of said first and said second fluid displacers and converting a rotary movement of the prime mover into a reciprocating stroke movement of said first and said second fluid displacers resulting in a continuous fluid flow free of fluid pulsing.

What is claimed is: 
     
         1 . A fluid metering pump comprising:
 a first reciprocating pump including a first fluid displacer;   a second reciprocating pump include a second fluid displacer   a transmission and stroke adjuster assembly for coupling a prime mover to each of said first and said second fluid displacers and converting a rotary movement of the primer mover into a reciprocating stroke movement of said first and said second fluid displacers;   said transmission and stroke adjuster assembly including:   a driven shaft rotatable about an axis of rotation;   first and second three-dimensional cam members mounted to said driven shaft for conjoined rotation therewith, said first and second cam members are congruent with respect to one another;   a first pair of followers in contact with said first cam member on opposite sides thereof, said first pair of followers connected to said first fluid displacer and imparting a reciprocating motion on said first fluid displacer during rotation of said driven shaft;   a second pair of followers in contact with said second cam member on opposite sides thereof, said second pair of followers connected to said second fluid displacer and imparting a reciprocating motion on said second fluid displacer during rotation of said driven shaft; and   wherein said first cam member and said second cam member each have a non-cardioid shape cam profile that results in a constant velocity reciprocation motion of said first and second pair of followers during rotation of said driven shaft.   
     
     
         2 . The metering pump of  claim 1 , wherein said first and second pair of followers are longitudinally positional across the cam profile of said first cam member and across the cam profile of said second cam member, respectively, and wherein the longitudinal position of said first and said second pair of followers relative to the cam profile of said first cam member and the cam profile of said second cam member, respectively, varies the stroke length of said first and said second pair of followers between a minimum stroke length and a maximum stroke length. 
     
     
         3 . The metering pump of  claim 1 , further comprising:
 a first intermediate shaft connecting said first pair of followers and said first fluid displacer; and   a second intermediate shaft connecting said second pair of followers and said second fluid displacer.   
     
     
         4 . The metering pump of  claim 3 , wherein said first intermediate shaft is split shaft comprising two interconnectable shaft portions; and wherein said second intermediate shaft is a split shaft comprising two interconnectable shaft portion. 
     
     
         5 . The metering pump of  claim 1 , wherein said first and said second fluid displacers are each diaphragms. 
     
     
         6 . The metering pump of  claim 2 , wherein said first and second cam members are mounted to said driven shaft for axial translation along said driven shaft; and
 wherein transmission and stroke adjuster assembly further includes:   a stroke adjuster frame supported for translation in a direction along said rotational axis of said driven shaft, said stroke adjuster frame connected to said first and said second cam members for conjoined translational movement therewith, wherein translational movement of said stroke adjuster frame causes an equal translational movement of said first and second cam members along said driven shaft.