# US 9,752,709 B2 · Hydraulic fitting insert > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,709 B2 - Document ID: US9752709B2 - Status: Granted - Kind: B2 - Application number: 14/341,649 - Filed: 2014-07-25 - Published: 2016-01-28 - Granted: 2017-09-05 - Earliest claimed: 2014-07-25 - Assignees: Catepillar Inc. - Applicants: Caterpillar Inc. - Inventors: Jeremy Killingbeck; Bruce Reynolds; James Atherton; Joseph Louks - Web page: https://patentgrep.com/patent/US9752709B2 ## CPC - F16L 15/04: with additional sealings - F16L 15/009: {with axial sealings having at least one plastically deformable sealing surface (with sealing rings F16L15/008)} - F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL ## Abstract A hydraulic system includes a housing having a housing bore defined by a bore inner surface, wherein the bore inner surface has an internal thread formed thereon and an insert having a flange formed adjacent a first end, a sealing feature formed adjacent a second end opposite the first end, and a cylindrical outer surface extending between the first end and the second end, the cylindrical outer surface having an external buttress thread configured to mesh with the internal thread of the housing bore. The sealing feature and the flange are configured to interface with the housing to provide a fluid seal. ## Claims ### Claim 1 An insert for a hydraulic bore, the insert comprising: an insert body defining a longitudinal axis, and including a first end, and a second end opposite the first end; a flange formed adjacent the first end, the flange configured to contact an outer surface of a hydraulic component, an annular sealing feature formed adjacent the second end, the sealing feature configured to form a seal, and a cylindrical outer surface and a cylindrical inner surface extending between the first end and the second end, the cylindrical outer surface having an external buttress thread to engage threads on the hydraulic component, the sealing feature further including a concave inner curved surface adjacent to the second end, and a convex outer curved surface that is positioned opposite to the concave inner curved surface and extends from the external buttress thread to the second end, and the concave inner curved surface and the convex outer curved surface together forming a taper that narrows toward the second end, the convex outer curved surface forming a first slope in a radially outward to radially inward direction at a first location adjacent to the external buttress thread, and a second slope in the radially outward to radially inward direction at a second location adjacent to the second end, and wherein the second slope is steeper than the first slope, and the cylindrical inner surface and the cylindrical outer surface forming a radial thickness relative to the longitudinal axis, and the annular sealing feature being contained entirely within the radial thickness. ### Claim 2 (depends on 1) The insert of claim 1, wherein the insert is formed from a high tensile steel material. ### Claim 3 (depends on 1) The insert of claim 1, wherein the sealing feature comprises a compression interface. ### Claim 4 (depends on 3) The insert of claim 3, wherein the compression interface comprises the convex outer curved surface, the concave inner curved surface, and a bottom interface surface. ### Claim 5 (depends on 1) The insert of claim 1, wherein the insert has an insert bore formed therethrough, the insert bore defined by an inner surface having an internal thread formed thereon. ### Claim 6 (depends on 1) A hydraulic system having the insert of claim 1, wherein the system comprises the hydraulic component including a housing that has an annular channel formed therein to receive the sealing feature of the insert. ### Claim 7 A hydraulic system comprising: a housing having a housing bore defined by a bore inner surface, wherein the bore inner surface has an internal thread formed thereon; and an insert having an insert body defining a longitudinal axis, and including a first end, and a second end opposite the first end, and having a flange formed adjacent the first end, an annular sealing feature formed adjacent the second end, and a cylindrical outer surface and a cylindrical inner surface extending between the first end and the second end, the cylindrical outer surface having an external buttress thread configured to mesh with the internal thread of the housing bore, wherein the sealing feature and the flange are configured to interface with the housing to provide a fluid seal, the sealing feature further including a concave inner curved surface adjacent to the second end, and a convex outer curved surface that is positioned opposite to the concave inner curved surface and extends from the external buttress thread to the second end, and the concave inner curved surface and the convex outer curved surface together forming a taper that narrows toward the second end, the convex outer curved surface forming a first slope in a radially outward to radially inward direction at a first location adjacent to the external buttress thread, and a second slope in the radially outward to radially inward direction at a second location adjacent to the second end, and wherein the second slope is steeper than the first slope, and the cylindrical inner surface and the cylindrical outer surface forming a radial thickness relative to the longitudinal axis, and the annular sealing feature being contained entirely within the radial thickness. ### Claim 8 (depends on 7) The hydraulic system of claim 7, wherein the housing bore is a hydraulic port. ### Claim 9 (depends on 7) The hydraulic system of claim 7, wherein the housing is part of a high pressure pump. ### Claim 10 (depends on 7) The hydraulic system of claim 7, wherein the housing is formed from a low tensile material, and wherein the insert is formed from a high tensile material. ### Claim 11 (depends on 7) The hydraulic system of claim 7, wherein the sealing feature comprises a compression interface. ### Claim 12 (depends on 7) The hydraulic system of claim 7, wherein the housing has an annular channel formed therein to receive the sealing feature of the insert. ### Claim 13 (depends on 7) The hydraulic system of claim 7, wherein the insert has an insert bore formed therethrough, the insert bore defined by an inner surface having an internal thread formed thereon. ### Claim 14 (depends on 13) The hydraulic system of claim 13, further comprising a fitting having an external thread configured to mesh with the internal thread of the insert bore. ### Claim 15 (depends on 14) The hydraulic system of claim 14, further comprising an annular seal disposed between the fitting and the insert. ### Claim 16 (depends on 15) The hydraulic system of claim 15, wherein the annular seal is disposed adjacent an inner surface of the flange of the insert.