Multichannel pump apparatus with microflow rate capability
First Claim
1. A fluid gradient proportioning system, comprising:
- a plurality of reservoirs each containing one of a plurality of different fluids;
a plurality of pumps, each said pump being connected to a different corresponding one of said reservoirs, each said pump being a direct drive pump having a central housing having first and second ends;
a chamber housing mechanically attached to said central housing at said second end, and enclosing an elongated chamber having an opening at one end, said elongated chamber defining an inlet, and an outlet;
a piston having a drive end and a fluid end, each fluid end being slidably received within said chamber through said opening;
a bidirectional motor mounted to said first end of said central housing and having a motor shaft which rotates about a linear axis; and
motor connection means mounted within said central housing for directly drivingly connecting said drive end of said piston to said motor shaft with said motor shaft and said piston being arranged substantially colinearly along said linear axis, said motor connection means including a proximal portion having a first end mechanically affixed to said motor shaft for rotation in synchrony therewith about said axis and an externally threaded second end, and a distal portion coupled to said drive end of said piston and including mounting means operably mounted to said central housing for mounting said piston for slidable motion along the direction defined by said axis, said mounting means having an internally threaded cavity operably disposed and dimensioned for incremental and reversible engagement and rotation of said threaded second end of said proximal portion, said motor connection means further including a floating connection means for connecting said piston to said motor connection means, said floating connection means comprising a traveling bracket forming the distal end of said motor connection means and having attachment means for attaching said drive end of said piston;
at least one mixing unit having a plurality of inlets, each of said inlets connectable to receive fluid from a different one of said pumps, and said mixing unit having an outlet for discharging mixed fluid; and
system control means communicatively connected to each of said pumps for controlling said pumps, said system control means being constructed to control said pumps to pump at selected individual rates to produce a mixture in said mixing unit having said different fluids in proportions determined by the relative pumping rates of corresponding said pumps.
1 Assignment
0 Petitions
Accused Products
Abstract
A multichannel pump system for HPLC and other uses has a plurality of fluid pumps whose input is fed separately to at least one high pressure mixing unit downstream of the pumps and any associated items such as pulse dampeners and pressure transducers. A pump controller is connected to control each of the pumps separately in a coordinated manner to provide a plurality of operational modes. The operational modes include an isocratic mode, in which optionally the output of solvent of like composition from two or more pumps is pooled to provide increased output capacity, as well as binary, ternary, etc., gradient modes in which different solvents are selectively mixed before being applied to an analytical unit such as an HPLC column. The pump system further includes a novel linear drive pump having interchangeable piston modules providing different ranges of flow rates. The linear drive pump is capable of providing precise solvent delivery at high pressure for flow rates from 20 ml/minute down to 0.0001 ml/minute, and is particularly useful because of its microflow gradient elution capability.
-
Citations
53 Claims
-
1. A fluid gradient proportioning system, comprising:
-
a plurality of reservoirs each containing one of a plurality of different fluids; a plurality of pumps, each said pump being connected to a different corresponding one of said reservoirs, each said pump being a direct drive pump having a central housing having first and second ends; a chamber housing mechanically attached to said central housing at said second end, and enclosing an elongated chamber having an opening at one end, said elongated chamber defining an inlet, and an outlet; a piston having a drive end and a fluid end, each fluid end being slidably received within said chamber through said opening; a bidirectional motor mounted to said first end of said central housing and having a motor shaft which rotates about a linear axis; and motor connection means mounted within said central housing for directly drivingly connecting said drive end of said piston to said motor shaft with said motor shaft and said piston being arranged substantially colinearly along said linear axis, said motor connection means including a proximal portion having a first end mechanically affixed to said motor shaft for rotation in synchrony therewith about said axis and an externally threaded second end, and a distal portion coupled to said drive end of said piston and including mounting means operably mounted to said central housing for mounting said piston for slidable motion along the direction defined by said axis, said mounting means having an internally threaded cavity operably disposed and dimensioned for incremental and reversible engagement and rotation of said threaded second end of said proximal portion, said motor connection means further including a floating connection means for connecting said piston to said motor connection means, said floating connection means comprising a traveling bracket forming the distal end of said motor connection means and having attachment means for attaching said drive end of said piston; at least one mixing unit having a plurality of inlets, each of said inlets connectable to receive fluid from a different one of said pumps, and said mixing unit having an outlet for discharging mixed fluid; and system control means communicatively connected to each of said pumps for controlling said pumps, said system control means being constructed to control said pumps to pump at selected individual rates to produce a mixture in said mixing unit having said different fluids in proportions determined by the relative pumping rates of corresponding said pumps. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
-
Specification