Patents by Inventor Andrew J. Loetz

Andrew J. Loetz 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).

  • Publication number: 20240093659
    Abstract: A piston may have an annular body including a crown portion defining a longitudinal axis, a radial direction perpendicular to the longitudinal axis, a plane containing the longitudinal axis and the radial direction, and a contoured combustion bowl. In the plane containing the longitudinal axis and the radial direction, the crown portion includes a radially outer squish surface, and a swirl pocket having a reentrant surface that extends axially downwardly and radially outwardly from the squish surface defining a tangent that forms a reentrant angle with the squish surface that ranges from 53.0 degrees to 57.0 degrees.
    Type: Application
    Filed: November 16, 2023
    Publication date: March 21, 2024
    Applicant: Caterpillar Inc.
    Inventors: Aaron S. Ness, Andrew J. Loetz, John R. Brubaker, Christopher L. Batta
  • Patent number: 11840983
    Abstract: A piston may have an annular body including a crown portion defining a longitudinal axis, a radial direction perpendicular to the longitudinal axis, a plane containing the longitudinal axis and the radial direction, and a contoured combustion bowl. In the plane containing the longitudinal axis and the radial direction, the crown portion includes a radially outer squish surface, and a swirl pocket having a reentrant surface that extends axially downwardly and radially outwardly from the squish surface defining a tangent that forms a reentrant angle with the squish surface that ranges from 53.0 degrees to 57.0 degrees.
    Type: Grant
    Filed: February 22, 2022
    Date of Patent: December 12, 2023
    Assignee: Caterpillar Inc.
    Inventors: Aaron S. Ness, Andrew J. Loetz, John R. Brubaker, Christopher L. Batta
  • Publication number: 20230265810
    Abstract: A piston may have an annular body including a crown portion defining a longitudinal axis, a radial direction perpendicular to the longitudinal axis, a plane containing the longitudinal axis and the radial direction, and a contoured combustion bowl. In the plane containing the longitudinal axis and the radial direction, the crown portion includes a radially outer squish surface, and a swirl pocket having a reentrant surface that extends axially downwardly and radially outwardly from the squish surface defining a tangent that forms a reentrant angle with the squish surface that ranges from 53.0 degrees to 57.0 degrees.
    Type: Application
    Filed: February 22, 2022
    Publication date: August 24, 2023
    Applicant: Caterpillar Inc.
    Inventors: Aaron S. Ness, Andrew J. Loetz, John R. Brubaker, Christopher L. Batta
  • Patent number: 11047341
    Abstract: A system and method for combustion in an engine includes a combustion chamber, a prechamber, and a fluid injector. The prechamber extends from a first end to a second is fluidly connected to the combustion chamber through at least one port positioned at the first end of the prechamber. The fluid injector is configured to introduce a fluid into the prechamber following combustion of an air-fuel mixture within the prechamber and positioned to introduce the fluid into the prechamber at the second end of the prechamber.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: June 29, 2021
    Assignee: Caterpillar Inc.
    Inventor: Andrew J. Loetz
  • Patent number: 10815912
    Abstract: A reformer system may include a reformer device having a fuel inlet, an air inlet and a gas outlet, a first valve set coupled to the fuel inlet and configured to selectively supply a reformer fuel flow from an engine fuel flow to the fuel inlet, a second valve set coupled to the air inlet and configured to selectively supply a reformer air flow from a compressor outlet air flow to the air inlet, and a controller in electrical communication with the first valve set and the second valve set. The controller may determine a target reformer fuel flow based on a target gas flow, determine a target reformer air flow based on the reformer fuel flow and a target air-to-fuel ratio, adjust the reformer fuel flow according to the target reformer fuel flow, and adjust the reformer air flow according to the target reformer air flow.
    Type: Grant
    Filed: August 1, 2016
    Date of Patent: October 27, 2020
    Assignee: Caterpillar Inc.
    Inventors: Deepti Bhosekar, Venkat Vijay Kishore Turlapati, Brett A. Zook, Andrew J. Loetz
  • Publication number: 20200149498
    Abstract: A system and method for combustion in an engine includes a combustion chamber, a prechamber, and a fluid injector. The prechamber extends from a first end to a second is fluidly connected to the combustion chamber through at least one port positioned at the first end of the prechamber. The fluid injector is configured to introduce a fluid into the prechamber following combustion of an air-fuel mixture within the prechamber and positioned to introduce the fluid into the prechamber at the second end of the prechamber.
    Type: Application
    Filed: November 13, 2018
    Publication date: May 14, 2020
    Applicant: Caterpillar Inc.
    Inventor: Andrew J. Loetz
  • Publication number: 20180030907
    Abstract: A reformer system may include a reformer device having a fuel inlet, an air inlet and a gas outlet, a first valve set coupled to the fuel inlet and configured to selectively supply a reformer fuel flow from an engine fuel flow to the fuel inlet, a second valve set coupled to the air inlet and configured to selectively supply a reformer air flow from a compressor outlet air flow to the air inlet, and a controller in electrical communication with the first valve set and the second valve set. The controller may determine a target reformer fuel flow based on a target gas flow, determine a target reformer air flow based on the reformer fuel flow and a target air-to-fuel ratio, adjust the reformer fuel flow according to the target reformer fuel flow, and adjust the reformer air flow according to the target reformer air flow.
    Type: Application
    Filed: August 1, 2016
    Publication date: February 1, 2018
    Applicant: Caterpillar Inc.
    Inventors: Deepti Bhosekar, Venkat Vijay Kishore Turlapati, Brett A. Zook, Andrew J. Loetz
  • Publication number: 20160069251
    Abstract: An engine with a main combustion chamber and a pre-combustion chamber assembly is provided. The pre-combustion chamber assembly includes a pre-combustion chamber, a pressure-limiting device, and a fluid conduit. The pressure-limiting device includes a first end and a second end. The first end includes a spring. The second end is exposed to the pre-combustion chamber. The pressure-limiting device is operable in a passive state and an active state. The fluid conduit is disposed between the main combustion chamber and the first end of the pressure-limiting device to facilitate fluid communication between the main combustion chamber and the pressure-limiting device. The pressure-limiting device is actuated to the active state when fluid pressure in the pre-combustion chamber reaches a threshold value during pre-chamber combustion. In the active state, the pressure-limiting device moves away from the pre-combustion chamber, to increase a volume in the pre-combustion chamber.
    Type: Application
    Filed: November 13, 2015
    Publication date: March 10, 2016
    Applicant: Caterpillar Inc.
    Inventor: Andrew J. Loetz
  • Publication number: 20160069250
    Abstract: An engine with a cylinder, a cylinder head, a main combustion chamber, a pre-combustion chamber assembly, and a control valve is provided. The main combustion chamber is disposed in the cylinder. The pre-combustion chamber assembly is disposed in the cylinder head. The pre-combustion chamber assembly includes a pre-chamber portion in fluid communication with the main combustion chamber. The pre-combustion chamber assembly includes a tip portion, which includes at least one orifice to allow fluid communication between the main combustion chamber and the pre-chamber portion. The control valve is accommodated in the pre-chamber portion and is mechanically switchable between a closed position and an open position. The control valve is adapted to be switched to the closed position when fluid pressure in the pre-chamber portion reaches a peak pressure value. The control valve then blocks fluid communication between the main combustion chamber and the pre-chamber portion.
    Type: Application
    Filed: November 13, 2015
    Publication date: March 10, 2016
    Applicant: Caterpillar Inc.
    Inventor: Andrew J. Loetz
  • Publication number: 20160061096
    Abstract: A combustion cylinder for an engine is disclosed. The combustion cylinder includes a main combustion chamber and a pre-combustion chamber. The pre-combustion chamber is fluidly connected to the main combustion chamber through a plurality of passages. The pre-combustion chamber includes an inner peripheral portion. The inner peripheral portion and the plurality of passages are coated with a layer of a NOx reducing catalyst.
    Type: Application
    Filed: November 6, 2015
    Publication date: March 3, 2016
    Applicant: Caterpillar Inc.
    Inventor: Andrew J. Loetz
  • Publication number: 20160061095
    Abstract: A fuel injection system for an engine is described. The fuel injection system includes a prechamber assembly mounted on a cylinder head of the engine. The prechamber assembly includes a prechamber located upstream of a combustion chamber of the engine and configured to receive air-fuel mixture. Further, the prechamber assembly includes a fuel injector to controllably supply fuel into the prechamber, where the supplied fuel mixes with the air-fuel mixture to form a homogeneous mixture of air and fuel at a predefined stoichiometric ratio. The prechamber assembly also includes a spark plug disposed at a downstream region of the prechamber, the downstream region being proximal to the combustion chamber of the engine. The fuel injection system also includes a controller operably coupled to the fuel injector, where the controller is configured to control the predefined stoichiometric ratio of air to fuel in in the prechamber.
    Type: Application
    Filed: November 6, 2015
    Publication date: March 3, 2016
    Applicant: Caterpillar Inc.
    Inventors: Andrew J. Loetz, Joel D. Hiltner
  • Publication number: 20160053672
    Abstract: A fuel supply system for an engine is disclosed. The fuel supply system includes a prechamber assembly in fluid communication with a fuel supply line having a first end and a second end. The prechamber assembly is enclosed within a cylinder head of the engine. The prechamber assembly further includes a pre-combustion chamber located upstream of a main combustion chamber. The pre-combustion chamber is adapted to supply fuel into the main combustion chamber. The prechamber assembly further includes a check valve that is located upstream of the pre-combustion chamber. The fuel supply system further includes a fuel injector that is adapted to fluidly communicate with the check valve of the prechamber assembly. The fuel injector is located upstream of the check valve and in fluid communication with the fuel supply line. The fuel supply system further includes a controller in electric communication with the fuel injector.
    Type: Application
    Filed: November 5, 2015
    Publication date: February 25, 2016
    Applicant: Caterpillar Inc.
    Inventors: Andrew J. Loetz, Joel D. Hiltner
  • Publication number: 20160053667
    Abstract: A prechamber assembly for an engine is disclosed. The prechamber assembly includes an air-fuel chamber and a prechamber in fluid communication with the air-fuel chamber via a conduit. The conduit includes a first end disposed in the air-fuel chamber and a second end disposed in the prechamber to allow premixed air-fuel mixture to flow from the air-fuel chamber to the prechamber. The prechamber is to receive a lean air-fuel mixture during a compression stroke of the engine. Further, the prechamber assembly also includes a valve disposed at the first end of the conduit, the valve configured to allow the premixed air-fuel mixture to flow from the air-fuel chamber to the prechamber. The premixed air-fuel mixture entering the prechamber mixes with the lean air-fuel mixture to form a stoichiometric ratio of a rich air-fuel mixture.
    Type: Application
    Filed: November 2, 2015
    Publication date: February 25, 2016
    Applicant: Caterpillar Inc.
    Inventors: Andrew J. Loetz, Robert J. Maxson, Joel D. Hiltner
  • Publication number: 20160053668
    Abstract: A prechamber assembly for an engine is provided. The prechamber assembly includes a prechamber located upstream of a main combustion chamber and adapted to receive fuel from a fuel supply system of the engine. The prechamber includes a first portion, a taper portion, and a second portion. The prechamber assembly further includes a fuel injection member located downstream of the taper portion of the prechamber and fluidly connected to the second portion of the prechamber. The fuel injection member is inclined at an angle with respect to a central axis of the prechamber. The fuel injection member is in electric communication with a controller. The controller is configured to actuate the fuel injection member to supply the fuel into the second portion of the prechamber to provide rich mixing of the fuel with an air-fuel mixture received from the main combustion chamber during operation of the engine.
    Type: Application
    Filed: November 2, 2015
    Publication date: February 25, 2016
    Applicant: Caterpillar Inc.
    Inventors: Andrew J. Loetz, Joel D. Hiltner