US 11,774,415 B2
Metering pump for liquid chromatography
Joshua A. Burnett, Taunton, MA (US); Rose Solow, Newark, NJ (US); David A. Simpson, Hopkinton, MA (US); Peter Osswald, Douglas, MA (US); John M. Auclair, Seekonk, MA (US); and Michael LeBeau, Attleboro, MA (US)
Assigned to WATERS TECHNOLOGIES CORPORATION, Milford, MA (US)
Filed by Waters Technologies Corporation, Milford, MA (US)
Filed on Mar. 25, 2021, as Appl. No. 17/212,329.
Claims priority of provisional application 63/000,037, filed on Mar. 26, 2020.
Prior Publication US 2021/0302397 A1, Sep. 30, 2021
Int. Cl. G01N 30/28 (2006.01); G01N 30/02 (2006.01); G01N 30/32 (2006.01)
CPC G01N 30/28 (2013.01) [G01N 2030/027 (2013.01); G01N 2030/326 (2013.01); G01N 2030/328 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A metering pump, comprising:
a pump housing having an axial bore and a slot parallel to an axis of the axial bore;
a drive nut having a bore with internal threads and having an opening, the drive nut disposed in the axial bore of the pump housing;
an anti-rotation guide pin at least partially disposed in the opening of the drive nut and extending into the slot of the pump housing;
a lead screw having a threaded outer surface in engagement with the threaded bore of the drive nut;
a pusher element secured to the drive nut and having a convex surface; and
a plunger having an end in contact with the convex surface of the pusher element,
wherein a rotation of the lead screw imparts an axial translation to the drive nut, pusher element and plunger.