Valve assembly for a gas chromatograph
AssigneeLdetek Inc.
InventorsXavier Simard-Lecours, Dany Gagne, Louis Paradis
Life of this patent
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Abstract
The valve assembly includes a main valve body defining a first inner cylindrical cavity, a support plate positioned above the main valve body, and an upper valve head positioned above the support plate. The upper valve head includes a bottom planar bottom surface and a plurality of discrete conduits, each conduit extending between an outer end and an inner end. The valve assembly further includes a sealing diaphragm interposed between the support plate and the upper valve head. The diaphragm can be engaged by plungers to selectively open or close corresponding gas circuits.
Claims20
A valve assembly for a gas chromatograph, the valve assembly including:
- a main valve body defining a first inner cylindrical cavity coaxially disposed with reference to a central axis;
- a support plate positioned above the main valve body and including a planar upper surface that is generally normal to the central axis, the planar upper surface having a surface groove circumferentially-disposed about the central axis and an array of holes extending generally parallel to the central axis across the support plate;
- an upper valve head positioned above the support plate, the upper valve head including a bottom planar bottom surface and a plurality of discrete conduits, each conduit extending between an outer end and an inner end;
- a sealing diaphragm interposed between the planar upper surface of the support plate and the planar bottom surface of the upper valve head;
- a first piston positioned inside the first inner cavity to reciprocate, along the central axis and relative to the sealing diaphragm, between at least a bottom position and an upper position, the first piston having a body defining a second inner cylindrical cavity;
- a second piston positioned inside the second inner cavity of the first piston to reciprocate, along the central axis and relative to the sealing diaphragm, between at least a bottom position and an upper position;
- a set of normally-closed plungers and a set of normally-opened plungers that are generally extending parallel to the central axis and disposed in a staggered arrangement, the normally-closed plungers being carried by the first piston and the normally-opened plungers being carried by the second piston;
- an actuating gas circuit extending through the body of the first piston to establish a fluid communication with a space located between a bottom surface of the second inner cavity and the second piston;
- a first force-generating mechanism to urge the first piston towards its upper position;
- and
- a second force-generating mechanism to urge the second piston towards its bottom position.
Dependencies are inferred from the claim text.