Dual pad liquid shear valve assembly
First Claim
1. A dual-pad liquid shear valve assembly for isolating a first, relatively small prescribed volume of sample liquid from a larger volume of sample liquid presented to said valve assembly from a source of sample liquid and for positioning said prescribed volume of sample liquid for subsequent dispensing together with a diluent adapted to dilute said sample liquid, said valve assembly comprising:
- a first valve pad having a first planar surface and containing a first plurality of liquid pathways therethrough which intersect said first planar surface;
a second valve pad having a second planar surface and containing a second plurality of liquid pathways therethrough which intersect said second planar surface, said first and second planar surfaces of said first and second valve pads slidably engaging each other to enable selected ones of said first plurality of liquid pathways to be moved into and out of liquid flow alignment with selected ones of said second plurality of liquid pathways, said second planar surface having formed therein an open, liquid-retention channel having a volume equal to said prescribed volume, said open, liquid-retention channel being positioned on said second planar surface to be selectively aligned and coupled with (i) a first pair of liquid pathways of said first valve pad during relative sliding movement between said first and second planar surfaces to enable said open, liquid-retention channel to be filled with a sample liquid supplied by a sample liquid source, and (ii) a second pair of liquid pathways of said first valve pad during relative sliding movement between said first and second planar surfaces to enable said prescribed volume of sample liquid contained in said open, liquid-retention channel to be dispensed therefrom by the introduction of a diluent into one of said second pair of liquid pathways.
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Accused Products
Abstract
A shear valve assembly comprises a pair of valve pads having opposing planar surfaces supported for relative sliding engagement. Each valve pad defines a plurality of liquid pathways by which a liquid can be passed from one pad to the other. The planar surface of one of the valve pads has an open channel formed therein, such channel having dimensions to accommodate a prescribed volume of liquid. Liquid is introduced into such channel via a first pair of pathways formed in the other valve pad, and liquid is dispensed from the open channel by a second pair of pathways that are brought into alignment with the channel during sliding movement between the valve pads. The valve assembly is particularly useful in blood-analyzing instruments for isolating and dispensing relatively minute volumes (of the order of microliters) of whole blood for analysis.
27 Citations
18 Claims
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1. A dual-pad liquid shear valve assembly for isolating a first, relatively small prescribed volume of sample liquid from a larger volume of sample liquid presented to said valve assembly from a source of sample liquid and for positioning said prescribed volume of sample liquid for subsequent dispensing together with a diluent adapted to dilute said sample liquid, said valve assembly comprising:
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a first valve pad having a first planar surface and containing a first plurality of liquid pathways therethrough which intersect said first planar surface;
a second valve pad having a second planar surface and containing a second plurality of liquid pathways therethrough which intersect said second planar surface, said first and second planar surfaces of said first and second valve pads slidably engaging each other to enable selected ones of said first plurality of liquid pathways to be moved into and out of liquid flow alignment with selected ones of said second plurality of liquid pathways, said second planar surface having formed therein an open, liquid-retention channel having a volume equal to said prescribed volume, said open, liquid-retention channel being positioned on said second planar surface to be selectively aligned and coupled with (i) a first pair of liquid pathways of said first valve pad during relative sliding movement between said first and second planar surfaces to enable said open, liquid-retention channel to be filled with a sample liquid supplied by a sample liquid source, and (ii) a second pair of liquid pathways of said first valve pad during relative sliding movement between said first and second planar surfaces to enable said prescribed volume of sample liquid contained in said open, liquid-retention channel to be dispensed therefrom by the introduction of a diluent into one of said second pair of liquid pathways. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A dual-pad shear valve assembly for isolating and dispensing a prescribed volume of whole blood in a blood-analyzing instrument, said shear valve assembly comprising:
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a first valve pad having a first planar surface and containing a first plurality of liquid pathways therethrough which intersect said first generally planar surface; and
a second valve pad having a second planar surface and containing a second plurality of liquid pathways therethrough which intersect said second planar surface, said second planar surface of said second valve pad slidably engaging said first planar surface of said first valve pad and being adapted to bring selected ones of said first plurality of liquid pathways into liquid flow alignment with selected ones of said second plurality of liquid pathways during sliding movement between said first and second planar surfaces, said second planar surface of said second valve pad having formed therein an open liquid-retention channel having a volume equal to said prescribed volume and being adapted to be coupled with liquid pathways of said first plurality of liquid pathways of said first valve pad, and wherein said first and second valve pads are adapted to be translated relative to one another so as to isolate said open liquid-retention channel of said second valve pad from liquid pathways of said first plurality of liquid pathways of said first valve pad. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification