RELEASE VALVE USED IN INNER TUBE ASSEMBLY FOR USE WITH CORE BARREL Russian patent published in 2018 - IPC E21B21/10 

FIELD: drilling soil or rock.

SUBSTANCE: group of inventions relates to core drilling of wells. Inner tube assembly comprises a head assembly and is configured to release the coring device fixed in the core barrel. Valve housing forms an internal bore extending axially in a direction between the first and second ends of the housing. At least one fluid flow port is provided through the valve housing to allow fluid communication with a region surrounding the valve housing and the bore. Valve body is configured to slide, is installed along the axis in order to open and close the flow port. Bias member acts on the valve body to bias the valve body in a first axial direction within the bore. Position guide is made to guide and control a position of the valve body within the bore. Valve body has a shape which enables movement in a second return axial direction within the bore, to open and close the flow port by a fluid pressure acting on the valve body via the second end of the housing. Assembly further comprises a valve pin mounted to be capable of axial movement within the bore to contact the valve body, the bias member having a shape to enable to bias the pin into contact with the valve body. Position guide comprises a slot provided in the housing and a guide pin extending radially from the valve body to be movable within the slot. Slot comprises a length having an angled section. Guide pin is capable of moving along the length and passing through the angle section, between the first length of the guide slot, and the second length and third length. Length of the third guide slot extends parallel to the longitudinal axis of the head assembly.

EFFECT: sensitivity of the valve to liquid pressure increases and the degree of its controllability increases.

12 cl, 27 dwg