Patents by Inventor Andrew Loetz

Andrew 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).

  • Patent number: 10724423
    Abstract: A prechamber assembly for a cylinder of a combustion engine is disclosed in which a plurality of ports placing a prechamber volume in fluid communication with the cylinder. A non-actuated, fixed orifice extends between the prechamber volume and a passageway formed in the prechamber assembly to permit combustion gases in the prechamber volume to enter the passageway. The passageway is configured to vent combustion gases therein out of the body. The orifice may reduce NOx emissions produced in the prechamber volume.
    Type: Grant
    Filed: February 16, 2017
    Date of Patent: July 28, 2020
    Assignee: Caterpillar Inc.
    Inventor: Andrew Loetz
  • Patent number: 10545066
    Abstract: A leak detection tool for a double walled fuel rail system is provided. The tool includes a body having a first end and a second end distal with respect to the first end. The tool includes a first passage extending from the first end at least partially towards the second end. The tool includes a second passage axially aligned with and extending from the first passage towards the second end. The tool includes a seat defined at an intersection of the first passage and the second passage. The tool also includes a sealing element provided in association with the seat within the second passage. The tool further includes a spring element provided within the second passage and in contact with the sealing element. The first end is configured to block fluid communication between outer passages of adjacent portions of the double walled fuel rail system.
    Type: Grant
    Filed: December 15, 2016
    Date of Patent: January 28, 2020
    Assignee: Caterpillar Inc.
    Inventors: Nicholas Edwin Wainscott, Jack Albert Merchant, Andrew Loetz
  • Publication number: 20180230894
    Abstract: A prechamber assembly for a cylinder of a combustion engine is disclosed in which a plurality of ports placing a prechamber volume in fluid communication with the cylinder. A non-actuated, fixed orifice extends between the prechamber volume and a passageway formed in the prechamber assembly to permit combustion gases in the prechamber volume to enter the passageway. The passageway is configured to vent combustion gases therein out of the body. The orifice may reduce NOx emissions produced in the prechamber volume.
    Type: Application
    Filed: February 16, 2017
    Publication date: August 16, 2018
    Applicant: Caterpillar Inc.
    Inventor: Andrew Loetz
  • Publication number: 20180172543
    Abstract: A leak detection tool for a double walled fuel rail system is provided. The tool includes a body having a first end and a second end distal with respect to the first end. The tool includes a first passage extending from the first end at least partially towards the second end. The tool includes a second passage axially aligned with and extending from the first passage towards the second end. The tool includes a seat defined at an intersection of the first passage and the second passage. The tool also includes a sealing element provided in association with the seat within the second passage. The tool further includes a spring element provided within the second passage and in contact with the sealing element. The first end is configured to block fluid communication between outer passages of adjacent portions of the double walled fuel rail system.
    Type: Application
    Filed: December 15, 2016
    Publication date: June 21, 2018
    Applicant: Caterpillar Inc.
    Inventors: Nicholas Edwin Wainscott, Jack Albert Merchant, Andrew Loetz
  • Patent number: 9903264
    Abstract: A control system for an engine cylinder having a pre-chamber and a main chamber includes a pressure sensor being provided in the pre-chamber, and a processor coupled to the pressure sensor. The processor is configured to measure pre-chamber pressure using the pressure sensor, determine a peak pre-chamber pressure from the measured pre-chamber pressure, calculate an estimated main chamber pressure corresponding to the peak pre-chamber pressure from at least one cylinder condition at ignition, calculate a pressure ratio of the peak pre-chamber pressure to the estimated main chamber pressure, calculate a fuel parameter for at least one of the pre-chamber and main chamber from the pressure ratio to achieve a desired pressure ratio, and generate a control signal to provide fuel to at least one of the pre-chamber and main chamber in accordance with the fuel parameter.
    Type: Grant
    Filed: October 18, 2016
    Date of Patent: February 27, 2018
    Assignee: Caterpillar Inc.
    Inventors: Mary Louise Yeager, Lucas Allen Burger, Andrew Loetz, Brett Zook
  • Publication number: 20170101922
    Abstract: In an aspect of the present disclosure, an internal combustion engine is disclosed. The internal combustion engine has a main combustion chamber, a prechamber, an insert in the prechamber, a fuel valve, and an ignition plug. The main combustion chamber is in fluid communication with the prechamber. The prechamber defines an upper volume and a lower volume about a central plane passing through a midpoint of the prechamber. The fuel valve is disposed in the upper volume and is configured to introduce charge into the prechamber. The ignition plug is configured to ignite the charge. The insert is disposed at least partially in the upper volume of the prechamber to promote mixing of the charge.
    Type: Application
    Filed: October 7, 2015
    Publication date: April 13, 2017
    Applicant: Caterpillar Inc.
    Inventors: Andrew Loetz, Yongxian Gu
  • Publication number: 20170101967
    Abstract: An internal combustion engine having a main combustion chamber, a prechamber and a fuel supply system is disclosed. The main combustion chamber is in fluid communication with the prechamber. The fuel supply system is connected to the prechamber for introducing fuel into the prechamber. Further, the fuel supply system has a catalyst to reform the fuel prior to introduction in the prechamber.
    Type: Application
    Filed: October 13, 2015
    Publication date: April 13, 2017
    Applicant: Caterpillar Inc.
    Inventor: Andrew Loetz
  • Publication number: 20170101923
    Abstract: An internal combustion engine having a main combustion chamber, a first prechamber, a second prechamber, a first ignition plug and a second ignition plug. The main combustion chamber is in fluid communication with a first prechamber and a second prechamber. The first ignition plug is disposed in the first prechamber for igniting a charge in the first prechamber to form a first flame jet directed into the main combustion chamber. The second ignition plug disposed in the second prechamber for igniting a charge in the second prechamber to form a second flame jet directed into the main combustion chamber. The first flame jet and the second flame jet overlap in the main combustion chamber.
    Type: Application
    Filed: October 7, 2015
    Publication date: April 13, 2017
    Applicant: Caterpillar Inc.
    Inventor: Andrew Loetz
  • Publication number: 20170089252
    Abstract: An internal combustion engine having a main combustion chamber, a prechamber, a first ignition plug and a second ignition plug. The main combustion chamber in fluid communication with the prechamber. The first ignition plug disposed in the prechamber for igniting a charge to form a flame jet directed into the main combustion chamber. The second ignition plug disposed in the main combustion chamber for igniting the charge in the main combustion chamber in the path of the flame jet from the prechamber. The second ignition plug configured to ignite the charge in the main combustion chamber prior to the ignition of the charge by the first ignition plug in the prechamber.
    Type: Application
    Filed: September 30, 2015
    Publication date: March 30, 2017
    Applicant: Caterpillar Inc.
    Inventors: Andrew Loetz, Joel Hiltner
  • Publication number: 20160237942
    Abstract: A fuel control system for an engine is provided. The fuel control system includes a first sensor configured to generate a signal indicative of a pressure within a cylinder of the engine, a second sensor configured to generate a signal indicative of an amount of Nitrous Oxide (NOx), a fuel reformer, an Air Fuel Ratio (AFR) unit, and a controller. The controller is configured to receive the signals indicative of the pressure and the amount of NOx. The controller is configured to determine a Coefficient of Variation (COV) of Indicated Mean Effective Pressure (IMEP) and compare the COV of IMEP and the amount of NOx with a threshold combustion stability and a threshold amount of NOx respectively. The controller is further configured to regulate at least one of the fuel reformer and the AFR unit to control at least one of the combustion stability and the amount of NOx.
    Type: Application
    Filed: April 25, 2016
    Publication date: August 18, 2016
    Applicant: Caterpillar Inc.
    Inventors: Scott Byron Fiveland, Andrew Loetz, Michael Flory, Joel Hiltner
  • Publication number: 20160169152
    Abstract: A piston includes a piston body forming a crown portion and a skirt portion, the crown portion forming a bowl surrounded by a flat crown surface having an annular shape and disposed along a plane, the bowl and the flat crown surface meeting along a rim of the bowl having a generally circular shape. A generally cylindrical surface surrounds the crown portion and forms at least two grooves that define top and bottom land surfaces. The top land surface has a height along a centerline of the piston, and the piston has a nominal outer diameter configured to reciprocally operate within a bore having an inner diameter such that a ratio between the height of the top land surface and the inner diameter of the bore is between 3% and 4.5%.
    Type: Application
    Filed: December 11, 2014
    Publication date: June 16, 2016
    Applicant: CATERPILLAR INC.
    Inventors: Lucas Burger, Andrew Palmer, Brandon Bowditch, Andrew Loetz