Patents by Inventor Ashwin Hattiangadi
Ashwin Hattiangadi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10934901Abstract: A valve seat insert of an engine has a valve seating surface including an outer curved segment forming a first wear crown for contacting the valve at an early wear state, an inner curved segment forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the outer and the inner curved segments.Type: GrantFiled: August 19, 2019Date of Patent: March 2, 2021Assignee: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Rong Qu
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Publication number: 20210054768Abstract: A valve seat insert of an engine has a valve seating surface including an outer curved segment forming a first wear crown for contacting the valve at an early wear state, an inner curved segment forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the outer and the inner curved segments.Type: ApplicationFiled: August 19, 2019Publication date: February 25, 2021Applicant: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Rong Qu
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Publication number: 20210054767Abstract: A cam follower assembly includes a cam roller, and a generally cylindrical body having an outer peripheral surface configured to be reciprocally slidable within a bore of an engine component. The cam roller is rotatably mounted on the body and configured to engage with a cam lobe on a camshaft of the engine. The cam lobe is operative to drive the body to a position at which the cam follower assembly causes one of opening of a valve or actuation of a fuel injector of the engine. A groove is formed in the body inset from the outer peripheral surface and extending axially along the outer peripheral surface parallel to the longitudinal axis of the body and aligned with an axial median plane of the cam roller and the cam lobe.Type: ApplicationFiled: August 22, 2019Publication date: February 25, 2021Applicant: CATERPILLAR INC.Inventors: Ashwin A. HATTIANGADI, John Stephen PIPIS, JR., Charles Francis COFFEY, Kevin Duane YODER, Vaibhav BALAJI
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Patent number: 10844758Abstract: A gas exchange valve in an internal combustion engine includes a valve head having a sealing face structured to contact a valve seat and defining a face angle. The valve head further includes an under-head fillet transitioning from the inner sealing face to a valve stem, and defining a chordal stress zone within the under-head fillet. The under-head fillet is formed by a material distributed according to a stress-diffusing contour within the chordal stress zone, and is blended with the inner sealing face at a blend angle that is less than the face angle and is in a range of about 18° to about 35°. The valve head contour is associated with resistance to chordal stress-induced fatigue failure.Type: GrantFiled: January 22, 2019Date of Patent: November 24, 2020Assignee: Caterpillar Inc.Inventors: Ashwin Hattiangadi, Rong Qu
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Publication number: 20200340593Abstract: A valve seat insert for a gas exchange valve controlling gas exchange of a cylinder includes an insert body having an inner peripheral surface, an outer peripheral surface, and a valve seating surface structured to contact the gas exchange valve at a closed position and profiled to limit valve recession thereof. The valve seating surface includes an arrangement of linear segments and curved segments forming crowns to contact the gas exchange valve at different wear states. The valve seat insert further includes a base material, and a hard-facing material metallurgically bonded to the base material and forming the valve seating surface.Type: ApplicationFiled: April 26, 2019Publication date: October 29, 2020Applicant: Caterpillar Inc.Inventors: Ashwin A Hattiangadi, Rong Qu, Paul Smallidge, Karen Snelling, Pay Broderson
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Publication number: 20200291827Abstract: A valve seat insert for a gas exchange valve such as an intake valve controlling gas exchange of a cylinder includes an insert body having an inner peripheral surface, an outer peripheral surface, and a valve seating surface structured to contact the gas exchange valve at a closed position and profiled to limit valve recession thereof. The valve seating surface includes an arrangement of linear segments and curved segments forming wear crowns to contact the gas exchange valve at different wear states. The valve seat insert is further structured by way of the inner peripheral surface with an incoming flow crown, and a venturi extending from the incoming flow crown toward a throat of the valve seat insert. The venturi accelerates incoming gas flow.Type: ApplicationFiled: March 13, 2019Publication date: September 17, 2020Applicant: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Srikanth Reddy Boddapati, Dongyao Wang, Uijal Paladhi, Paul David Smallidge, John Robert Brubaker, Abe Ingold
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Patent number: 10767520Abstract: A valve seat insert of an engine has a valve seating surface including an outer curved segment forming a first wear crown for contacting the valve at an early wear state, an inner curved segment forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the outer and the inner curved segments. A top flow crown is set off radially inward from the engine head, and a sloping segment extending from the top flow crown is oriented at an acute angle relative to the valve seat center axis.Type: GrantFiled: August 19, 2019Date of Patent: September 8, 2020Assignee: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Paul David Smallidge, Rong Qu
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Patent number: 10731523Abstract: An internal combustion engine includes a valve seat insert within an engine housing, and a gas exchange valve. The valve seat insert has a compound valve seat with a valve recession-resistive profile formed by a leading radius contacted by the valve seat at an early wear state of the valve head and valve seat insert, a trailing radius contacted by the valve head at a later wear state of the valve head and valve seat insert, and an outer seat face. The compound valve seat is shaped and proportioned to cushion contact by a gas exchange valve and retard valve recession.Type: GrantFiled: November 13, 2018Date of Patent: August 4, 2020Assignee: Caterpillar Inc.Inventors: Rong Qu, Ashwin Hattiangadi, Sanjay Kumar, Kevin D. Yoder
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Publication number: 20200232353Abstract: A gas exchange valve in an internal combustion engine includes a valve head having a sealing face structured to contact a valve seat and defining a face angle. The valve head further includes an under-head fillet transitioning from the inner sealing face to a valve stem, and defining a chordal stress zone within the under-head fillet. The under-head fillet is formed by a material distributed according to a stress-diffusing contour within the chordal stress zone, and is blended with the inner sealing face at a blend angle that is less than the face angle and is in a range of about 18° to about 35°. The valve head contour is associated with resistance to chordal stress-induced fatigue failure.Type: ApplicationFiled: January 22, 2019Publication date: July 23, 2020Applicant: Caterpillar Inc.Inventors: Ashwin Hattiangadi, Rong Qu
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Patent number: 10711655Abstract: A method of retrofitting a rocker arm assembly for an engine includes removing a first rocker arm assembly from the engine such that a camshaft of the engine remains in the engine. The method also includes providing a second rocker arm assembly that includes a rocker shaft, a rocker arm, a pushrod, and a hydraulic lash adjuster. The rocker arm is connected to the rocker shaft such that the rocker arm can pivot relative to the rocker shaft. The rocker arm has a first end, a second end, and a first oil passage. The pushrod has a top end and a bottom end, in which the top end is connected to the second end of the rocker arm and the bottom end is configured for engaging a camshaft of the engine. The hydraulic lash adjuster includes a housing, a first body member, a second body member, a check valve, and a biasing member. The first body member is disposed in the housing such that a first radial clearance exists between an outer surface of the first body member and an inner surface of the housing.Type: GrantFiled: October 7, 2019Date of Patent: July 14, 2020Assignee: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Charles F. Coffey, Kevin D. Yoder
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Publication number: 20200149441Abstract: A valve seat insert for a gas exchange valve controlling gas exchange of a cylinder includes an insert body having an inner peripheral surface, an outer peripheral surface, and a valve seating surface structured to contact the gas exchange valve at a closed position and profiled to limit valve recession thereof. The valve seating surface includes an arrangement of linear segments and curved segments forming crowns to contact the gas exchange valve at different wear states.Type: ApplicationFiled: November 13, 2018Publication date: May 14, 2020Applicant: Caterpillar Inc.Inventors: Ashwin Hattiangadi, Rong Qu, Sanjay Kumar, Kevin Yoder
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Publication number: 20200149440Abstract: An internal combustion engine includes a valve seat insert within an engine housing, and a gas exchange valve. The valve seat insert has a compound valve seat with a valve recession-resistive profile formed by a leading radius contacted by the valve seat at an early wear state of the valve head and valve seat insert, a trailing radius contacted by the valve head at a later wear state of the valve head and valve seat insert, and an outer seat face. The compound valve seat is shaped and proportioned to cushion contact by a gas exchange valve and retard valve recession.Type: ApplicationFiled: November 13, 2018Publication date: May 14, 2020Applicant: Caterpillar Inc.Inventors: Rong Qu, Ashwin Hattiangadi, Sanjay Kumar, Kevin D. Yoder
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Publication number: 20180334930Abstract: A rocker arm for an engine valve actuator assembly is disclosed. The rocker arm may include a rocker arm body disposed between a first and second arm end. Furthermore, a rocker arm bore and an adjuster compartment may be defined proximal to the second arm end. The rocker arm may further include a roller positioned at the first arm end and operably coupled to a cam, the cam configured to actuate the rocker arm between a first and second position. The rocker arm may further include a shaft inserted through a shaft mounting aperture and the rocker arm is configured to rotate about the shaft between the first and second positions. Furthermore, a fluid passage may be defined within the rocker arm body extending between a first passage opening formed in a bearing surface of the shaft mounting aperture and a second passage opening that opens into the adjuster compartment.Type: ApplicationFiled: May 19, 2017Publication date: November 22, 2018Applicant: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Selvakumar Selvaraj
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Patent number: 10132206Abstract: A rocker arm for an engine valve actuator assembly is disclosed. The rocker arm may include a rocker arm body disposed between a first and second arm end. Furthermore, a rocker arm bore and an adjuster compartment may be defined proximal to the second arm end. The rocker arm may further include a roller positioned at the first arm end and operably coupled to a cam, the cam configured to actuate the rocker arm between a first and second position. The rocker arm may further include a shaft inserted through a shaft mounting aperture and the rocker arm is configured to rotate about the shaft between the first and second positions. Furthermore, a fluid passage may be defined within the rocker arm body extending between a first passage opening formed in a bearing surface of the shaft mounting aperture and a second passage opening that opens into the adjuster compartment.Type: GrantFiled: May 19, 2017Date of Patent: November 20, 2018Assignee: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Selvakumar Selvaraj
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Patent number: 10082052Abstract: A replaceable hydraulic lash adjuster and method for assembling such are disclosed. The replaceable hydraulic lash adjuster includes a body, a piston, a check valve and a spring. The body configured to be received in and released from a compartment of a rocker arm. The body including a sidewall surrounding a floor. The floor including a passage that extends between an upper cavity and a lower cavity of the body. The piston disposed in the lower cavity. The piston defining a pocket. A check valve is disposed inside the lower cavity and a spring is disposed inside the pocket. The replacable hydraulic lash adjuster is configured to be slidingly removeable from the rocker arm.Type: GrantFiled: February 8, 2017Date of Patent: September 25, 2018Assignee: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Selvakumar Selvaraj
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Publication number: 20180223701Abstract: A replaceable hydraulic lash adjuster and method for assembling such are disclosed. The replaceable hydraulic lash adjuster includes a body, a piston, a check valve and a spring. The body configured to be received in and released from a compartment of a rocker arm. The body including a sidewall surrounding a floor. The floor including a passage that extends between an upper cavity and a lower cavity of the body. The piston disposed in the lower cavity. The piston defining a pocket. A check valve is disposed inside the lower cavity and a spring is disposed inside the pocket. The replacable hydraulic lash adjuster is configured to be slidingly removeable from the rocker arm.Type: ApplicationFiled: February 8, 2017Publication date: August 9, 2018Applicant: Caterpillar Inc.Inventors: Ashwin A. Hattiangadi, Selvakumar Selvaraj
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Patent number: 10006317Abstract: A valve actuation system is disclosed for use with an internal combustion engine. The valve actuation system may have a rocker shaft, a rocker arm pivotally mounted on the rocker shaft, at least one cam follower and a pushrod connecting the at least one cam follower to the rocker arm. The valve actuation system may also have a plurality of gas exchange valves, and a bridge connecting the rocker arm to the valves. The valve actuation system may further have at least one spring disposed around each of the valves and configured to bias each of the valves toward closed positions, and a rotocoil configured to rotatably connect the at least one spring to each of the valves. The rotocoil may have an internal chamfer at a bridge end with an angle of about 26-28°. The at least one spring may have an assembled load of about 750-850 N.Type: GrantFiled: September 29, 2015Date of Patent: June 26, 2018Assignee: Caterpillar Inc.Inventors: Indrajith Kizhakkethara, Gopinath Baskaran, Ashwin A. Hattiangadi, Rong Qu, Kevin W. Redinbo
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Publication number: 20170089223Abstract: A valve actuation system is disclosed for use with an internal combustion engine. The valve actuation system may have a rocker shaft, a rocker arm pivotally mounted on the rocker shaft, at least one cam follower and a pushrod connecting the at least one cam follower to the rocker arm. The valve actuation system may also have a plurality of gas exchange valves, and a bridge connecting the rocker arm to the valves. The valve actuation system may further have at least one spring disposed around each of the valves and configured to bias each of the valves toward closed positions, and a rotocoil configured to rotatably connect the at least one spring to each of the valves. The rotocoil may have an internal chamfer at a bridge end with an angle of about 26-28°. The at least one spring may have an assembled load of about 750-850 N.Type: ApplicationFiled: September 29, 2015Publication date: March 30, 2017Applicant: Caterpillar Inc.Inventors: Indrajith KIZHAKKETHARA, Gopinath BASKARAN, Ashwin A. HATTIANGADI, Rong Qu, Kevin W. REDINBO
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Patent number: 9523291Abstract: A valve actuation system is disclosed for an engine. The system may have at least one gas exchange valve, a rocker shaft, a camshaft, a rocker arm connected to the rocker shaft and operatively engaged with the camshaft, a valve bridge engaged with the at least one gas exchanger valve, a lash adjuster disposed in the valve bridge, and a button configured to slide on the valve bridge. The system may further include a pin fluidly connecting the rocker arm to the button and having an elongated cylindrical shaft with a first open end inside the rocker arm and a second end inside the button. The pin may also have a head connected to and a reservoir formed in the elongated cylindrical shaft. The pin may further have passages extending from the bore of the rocker arm to the reservoir, and s passage extending from the reservoir through the head.Type: GrantFiled: March 18, 2015Date of Patent: December 20, 2016Assignee: Caterpillar Inc.Inventors: Charles F. Coffey, Edwin H. Langewisch, Ashwin A. Hattiangadi, David A. Cyborski, John S. Pipis, Jr., Kevin D. Yoder
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Publication number: 20160273416Abstract: A valve actuation system is disclosed for an engine. The system may have at least one gas exchange valve, a rocker shaft, a camshaft, a rocker arm connected to the rocker shaft and operatively engaged with the camshaft, a valve bridge engaged with the at least one gas exchanger valve, a lash adjuster disposed in the valve bridge, and a button configured to slide on the valve bridge. The system may further include a pin fluidly connecting the rocker arm to the button and having an elongated cylindrical shaft with a first open end inside the rocker arm and a second end inside the button. The pin may also have a head connected to and a reservoir formed in the elongated cylindrical shaft. The pin may further have passages extending from the bore of the rocker arm to the reservoir, and s passage extending from the reservoir through the head.Type: ApplicationFiled: March 18, 2015Publication date: September 22, 2016Applicant: Caterpillar Inc.Inventors: Charles F. COFFEY, Edwin H. LANGEWISCH, Ashwin A. HATTIANGADI, David A. CYBORSKI, John S. PIPIS, JR., Kevin D. YODER