Patents by Inventor Paul John CAIRNS

Paul John CAIRNS 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: 11933290
    Abstract: An axial piston pump controller for an axial piston pump having a fixed valve plate and a variable displacement is provided. The axial piston pump controller is configured to determine a displacement of the axial piston pump, and to calculate a pump displacement control current to be supplied to the axial piston pump to control the displacement of the axial piston pump. Calculating the pump displacement control current comprises calculating a nominal value for the pump displacement control current based on a rotational speed of the axial piston pump, calculating a pump stiffness adjustment factor based on a pump stiffness control map having as inputs: an output pressure of the axial piston pump; and the estimated pump displacement, and calculating the pump displacement control current to be supplied to the axial piston pump based on the nominal value and the pump stiffness adjustment factor.
    Type: Grant
    Filed: August 12, 2022
    Date of Patent: March 19, 2024
    Assignee: Caterpillar Inc.
    Inventors: Arick Bakken, Paul John Cairns, William Christopher Swick
  • Patent number: 11726611
    Abstract: The present invention refers to a method for generating a control command to at least one actuator of an electrohydraulic machine, comprising a step of receiving and monitoring an input signal provided by a user interface, a step of determining if the monitored input signal is related to a user-induced input or a non-user-induced input, and a step of generating the control command upon processing the input signal in dependence on whether the input signal is a user-induced input or a non-user-induced input.
    Type: Grant
    Filed: March 17, 2021
    Date of Patent: August 15, 2023
    Assignee: Caterpillar Inc.
    Inventors: Niall Hugh McNamee, Fuaad Sayeed, Paul John Cairns, Arick M. Bakken
  • Publication number: 20230052785
    Abstract: An axial piston pump controller for an axial piston pump having a fixed valve plate and a variable displacement is provided. The axial piston pump controller is configured to determine a displacement of the axial piston pump, and to calculate a pump displacement control current to be supplied to the axial piston pump to control the displacement of the axial piston pump. Calculating the pump displacement control current comprises calculating a nominal value for the pump displacement control current based on a rotational speed of the axial piston pump, calculating a pump stiffness adjustment factor based on a pump stiffness control map having as inputs: an output pressure of the axial piston pump; and the estimated pump displacement, and calculating the pump displacement control current to be supplied to the axial piston pump based on the nominal value and the pump stiffness adjustment factor.
    Type: Application
    Filed: August 12, 2022
    Publication date: February 16, 2023
    Applicant: Caterplllar Inc.
    Inventors: Arick BAKKEN, Paul John Cairns, William Christopher Sweck
  • Patent number: 11512449
    Abstract: An excavator or other work machine includes a tilting bucket operated by a hydraulic actuator controlled by a bucket control valve responsive to control signals including a bucket shake control signal, which causes the bucket to move repeatedly in the rack and dump directions to shake debris from the bucket in a bucket shake operation. The actuator is powered by pressure from a hydraulic pump, and a control system includes an unloader valve to relieve pressure from the supply line to unload the pump when there is no demand for power. The control system is arranged to maintain a constant pressure signal in a load sensing line, to maintain the unloader valve constantly in a closed condition, for the duration of the bucket shake operation. This may be achieved by pressurising an actuator of a quick coupler to lock the bucket to the machine.
    Type: Grant
    Filed: December 14, 2021
    Date of Patent: November 29, 2022
    Assignee: Caterpillar SARL
    Inventors: Paul John Cairns, Fuaad Sayeed, Arick M. Bakken, Niall Hugh McNamee
  • Publication number: 20220186471
    Abstract: An excavator or other work machine includes a tilting bucket operated by a hydraulic actuator controlled by a bucket control valve responsive to control signals including a bucket shake control signal, which causes the bucket to move repeatedly in the rack and dump directions to shake debris from the bucket in a bucket shake operation. The actuator is powered by pressure from a hydraulic pump, and a control system includes an unloader valve to relieve pressure from the supply line to unload the pump when there is no demand for power. The control system is arranged to maintain a constant pressure signal in a load sensing line, to maintain the unloader valve constantly in a closed condition, for the duration of the bucket shake operation. This may be achieved by pressurising an actuator of a quick coupler to lock the bucket to the machine.
    Type: Application
    Filed: December 14, 2021
    Publication date: June 16, 2022
    Applicant: Caterpillar SARL
    Inventors: Paul John CAIRNS, Fuaad SAYEED, Arick M. BAKKEN, Niall Hugh MC NAMEE
  • Publication number: 20210311584
    Abstract: The present invention refers to a method for generating a control command to at least one actuator of an electrohydraulic machine, comprising a step of receiving and monitoring an input signal provided by a user interface, a step of determining if the monitored input signal is related to a user-induced input or a non-user-induced input, and a step of generating the control command upon processing the input signal in dependence on whether the input signal is a user-induced input or a non-user-induced input.
    Type: Application
    Filed: March 17, 2021
    Publication date: October 7, 2021
    Applicant: Caterpillar Inc.
    Inventors: Niall Hugh MCNAMEE, Fuaad SAYEED, Paul John CAIRNS, Arick M. BAKKEN