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US 10,767,446 B2Granted
Float valve sub
AssigneesJapan Agency for Marine-Earth Science and Technology, Nlc Co., Ltd.
InventorsYuichi Shimmoto, Eigou Miyazaki, Keita Akiyama, Masaki Kawahara, Tomoaki Suzuki
Life of this patent
Estimating the term…
Abstract
A concave section such as an extension section, a cutting section, and a notch section is provided to receive a lid of a float valve in an inside of outer tube assembly of a drill string. Thus, when the float valve is provided for the drill string, it is made possible to collect a core with a larger diameter by a thinner drill string, by expanding the inner diameter of the drill string.
Claims4
A float valve sub comprising:
- an outer tube assembly;
- and
- a float valve assembly arranged detachably in an inside of the outer tube assembly,
- wherein the float valve assembly comprises:
- a first end section having a cylindrical shape;
- a second end section having a cylindrical shape;
- a valve assembly middle section arranged between the first end section and the second end section;
- and
- a lid section attached to the first end section,
- wherein the lid section moves turnably between a first position for closing a passage of the first end section and a second position for opening the passage of the first end section,
- wherein the valve assembly middle section has a side opening through which a part of the lid section is possible to pass,
- wherein the outer tube assembly comprises:
- a first section having an inner circumference surface complementary to an outer circumference surface of the first end section to receive the first end section;
- a second section having an inner circumference surface complementary to an outer circumference surface of the second end section to receive the second end section;
- and
- an outer tube assembly middle section arranged between the first section and the second section,
- wherein the outer tube assembly middle section has a concave section possible to receive the lid section in the second position,
- wherein a minimum inner diameter of the first section is larger than a minimum inner diameter of the second section,
- wherein an inner diameter of the concave section is larger than the minimum inner diameter of the first section, and
- wherein the inner diameter of the concave section of the outer tube assembly middle section is larger than a value obtained by multiplying the inner diameter of the second end section of the float valve assembly by the square root of 2.
17 more elements
Dependencies are inferred from the claim text.