Proportioning pump
First Claim
1. A proportioning pump comprising:
- a base;
a shaft having an x-axis and means for supporting it on said base;
at least one roller cage assembly mounted on said shaft;
said roller cage assembly comprising a pair of laterally spaced and aligned plates each having a primary bore centered on said x-axis and through which passes said shaft, spaced a predetermined radius from the longitudinal axis of said primary bores are a plurality of secondary bores whose longitudinal axes describe circles in said laterally spaced plates, roller rods are journaled in said secondary bores;
elastic tubing adapted to be peristaltically compressed by said roller rods;
the outer perimeter of each of said roller rods describes an arc of a predetermined radius r1 from the x-axis of said primary bore when said roller cage assembly is rotated about its longitudinal axis; and
a platen pressure surface having a concave transverse curvature of a predetermined radius r2, said radius r2 being greater than r1 and having its center positioned below said x-axis on a perpendicular line passing vertically through said x-axis whereby the spacing between the arc described by the outer surface of said roller rods and said pressure surface gradually decreases from a predetermined maximum to a predetermined minimum and then gradually increases back to a predetermined maximum.
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Accused Products
Abstract
A proportioning pump for automatic fluid analysis apparatus comprising a base having an open chamber formed in its top, a drive shaft supported in the open chamber, and a platen member that closes the top of the open chamber. A pair of roller cage assemblies each have primary bores in their end plates allowing them to be mounted on the drive shaft. The end plates are pinned to the drive shaft so that they rotate as one. Spaced outwardly a predetermined radius from the longitudinal axis of the primary bores are a plurality of secondary bores whose longitudinal axes describe circles in the laterally spaced end plates. Roller rods are journaled in the secondary bores. The outer perimeter of each of the roller rods describes an arc of a predetermined radius from the axis of the primary bore when the roller cage assembly is rotated about its longitudinal axis. The platen member has a bottom pressure surface having a predetermined concave transverse curvature which is positioned with respect to the roller cage assembly such that the spacing between the arc described by the outer surface of the roller rods and the pressure surface gradually decreases from a predetermined maximum to a predetermined minimum and then gradually increases back to a predetermined maximum. A plurality of fluid flow tubes pass in a direction transverse to the axis of the pump and are captured between the top of the roller cage assemblies and the bottom of the platen member.
72 Citations
10 Claims
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1. A proportioning pump comprising:
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a base; a shaft having an x-axis and means for supporting it on said base; at least one roller cage assembly mounted on said shaft; said roller cage assembly comprising a pair of laterally spaced and aligned plates each having a primary bore centered on said x-axis and through which passes said shaft, spaced a predetermined radius from the longitudinal axis of said primary bores are a plurality of secondary bores whose longitudinal axes describe circles in said laterally spaced plates, roller rods are journaled in said secondary bores; elastic tubing adapted to be peristaltically compressed by said roller rods; the outer perimeter of each of said roller rods describes an arc of a predetermined radius r1 from the x-axis of said primary bore when said roller cage assembly is rotated about its longitudinal axis; and a platen pressure surface having a concave transverse curvature of a predetermined radius r2, said radius r2 being greater than r1 and having its center positioned below said x-axis on a perpendicular line passing vertically through said x-axis whereby the spacing between the arc described by the outer surface of said roller rods and said pressure surface gradually decreases from a predetermined maximum to a predetermined minimum and then gradually increases back to a predetermined maximum. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification