Self-cleaning poppet valve for a core testing apparatus

DETAILED DESCRIPTION It is an object of this invention to provide a self-cleaning poppet valve assembly for use with the transfer piston of an automatic core testing device and to provide a secure means for attaching an end plug or a disk to the upper end of the transfer piston.
In accordance with an aspect of this invention, I provide a transfer piston having upper and lower ends and having an internal passageway formed longitudinally therethrough.
An internal inverted valve seat having an orifice is formed in the internal passageway at the upper end of the piston.
A poppet valve assembly comprised of a second piston having upper and lower ends having a valve face formed at its upper end and a piston flange at its lower end, is slidably mounted in the internal passageway.
The poppet valve is operable to selectively move the valve face in contact with the valve seat to close the orifice or away from the valve seat to open the orifice.
Means are provided for positively flushing rock particles from the region around the valve seat and the valve face, into the internal passageway, where the debris is outwardly diverted to the external environment.
In another aspect of this invention, inner and outer gasket-retaining seats are formed around the upper end of the transfer piston.
I provide a gasket-retaining washer and inner and outer gasket seals mounted between the washer and the gasket seats.
A perforated end cap threadably engages, externally, the upper end of the transfer piston.
In another aspect of this invention, I provide an aperture in the transfer piston to provide communication between the internal passageway and the external environment.
An upwardly-tapered concave bushing, having a bore for leakingly slidably receiving the piston portion of the poppet valve assembly, is fixedly mounted inside the internal passageway, just below the aperture but above the poppet valve piston flange, for outwardly directing rock particles passing through the internal passageway, out through the aperture and into the external environment