Patents by Inventor Rikard Ljungkvist

Rikard Ljungkvist 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: 11701731
    Abstract: A method comprising an arc ignition phase (IP), an arc-stabilizing phase (AP) and a stable arc phase (SP). The arc stabilizing phase comprises an initial sub-phase (IS) comprising the step of feeding at least one hot wire (4, 12) at constant feed speed and a main sub-phase (MS) comprising the steps of feeding said hot wire at constant feed speed and feeding at least one cold wire (22) at constant feed speed. The stable arc phase comprises the steps of continuously adjusting the feed speed of the hot wire and continuously adjusting the feed speed of the cold wire. The invention also relates to a welding apparatus (1) for carrying out the method. The welding apparatus comprises a hot wire feeding means (150), a contact means (2), a cold wire feeding means (35) and a control unit (31).
    Type: Grant
    Filed: January 6, 2021
    Date of Patent: July 18, 2023
    Assignee: ESAB AB
    Inventors: Hannes Raudsepp, Martin Andersson, Tomas Johansson, Rikard Ljungkvist
  • Patent number: 11135670
    Abstract: A submerged arc welding apparatus includes a first wire feeder feeding a first hot wire towards a work piece; a first contact tube transferring current to the first hot wire for arc generation to create a weld puddle; a second wire feeder feeding a cold wire at a variable feed speed towards the weld puddle; one or more sensors configured to continuously measure, during a welding phase, at least a first active welding parameter related to at least the first hot wire; and a control unit. The control unit is configured to determine different target values for the variable feed speed of the cold wire based on different values of the at least a first active welding parameter such that a different target value for the variable feed speed of the cold wire is determined according to a different value of the at least a first active welding parameter.
    Type: Grant
    Filed: October 25, 2018
    Date of Patent: October 5, 2021
    Assignee: ESAB AB
    Inventors: Hannes Raudsepp, Martin Andersson, Tomas Johansson, Rikard Ljungkvist
  • Publication number: 20210197306
    Abstract: A method comprising an arc ignition phase (IP), an arc-stabilizing phase (AP) and a stable arc phase (SP). The arc stabilizing phase comprises an initial sub-phase (IS) comprising the step of feeding at least one hot wire (4, 12) at constant feed speed and a main sub-phase (MS) comprising the steps of feeding said hot wire at constant feed speed and feeding at least one cold wire (22) at constant feed speed. The stable arc phase comprises the steps of continuously adjusting the feed speed of the hot wire and continuously adjusting the feed speed of the cold wire. The invention also relates to a welding apparatus (1) for carrying out the method. The welding apparatus comprises a hot wire feeding means (150), a contact means (2), a cold wire feeding means (35) and a control unit (31).
    Type: Application
    Filed: January 6, 2021
    Publication date: July 1, 2021
    Inventors: Hannes Raudsepp, Martin Andersson, Tomas Johansson, Rikard Ljungkvist
  • Patent number: 10913127
    Abstract: A method comprising an arc ignition phase (IP), an arc-stabilizing phase (AP) and a stable arc phase (SP). The arc stabilizing phase comprises an initial sub-phase (IS) comprising the step of feeding at least one hot wire (4, 12) at constant feed speed and a main sub-phase (MS) comprising the steps of feeding said hot wire at constant feed speed and feeding at least one cold wire (22) at constant feed speed. The stable arc phase comprises the steps of continuously adjusting the feed speed of the hot wire and continuously adjusting the feed speed of the cold wire. The invention also relates to a welding apparatus (1) for carrying out the method. The welding apparatus comprises a hot wire feeding means (150), a contact means (2), a cold wire feeding means (35) and a control unit (31).
    Type: Grant
    Filed: November 2, 2012
    Date of Patent: February 9, 2021
    Assignee: ESAB AB
    Inventors: Hannes Raudsepp, Martin Andersson, Tomas Johansson, Rikard Ljungkvist
  • Publication number: 20190061040
    Abstract: A submerged arc welding apparatus includes a first wire feeder feeding a first hot wire towards a work piece; a first contact tube transferring current to the first hot wire for arc generation to create a weld puddle; a second wire feeder feeding a cold wire at a variable feed speed towards the weld puddle; one or more sensors configured to continuously measure, during a welding phase, at least a first active welding parameter related to at least the first hot wire; and a control unit. The control unit is configured to determine different target values for the variable feed speed of the cold wire based on different values of the at least a first active welding parameter such that a different target value for the variable feed speed of the cold wire is determined according to a different value of the at least a first active welding parameter.
    Type: Application
    Filed: October 25, 2018
    Publication date: February 28, 2019
    Inventors: Hannes Raudsepp, Martin Andersson, Tomas Johansson, Rikard Ljungkvist
  • Patent number: 10137521
    Abstract: The invention relates to a method for submerged arc welding comprising the steps of guiding a first hot wire (4; 4a, 4b) towards a work piece and guiding a cold wire (22; 22a, 22b) at a variable feed speed. The method further comprises the steps of continuously measuring, during a welding phase, at least a first active welding parameter related to at least said first hot wire (4; 4a, 4b) adjusting the cold wire (22; 22a, 22b) feed speed in dependence on at least first active welding parameter variations, to maintain high welding stability and high weld quality. The invention also relates to a system (9) for carrying out the method. The system (9) comprises hot wire feeding means (150) for feeding a first hot wire (4; 4a, 4b) towards a work piece and cold wire feeding means (35) for feeding a cold wire (22; 22a, 22b) at a variable cold wire (22; 22a, 22b) feed speed and a control unit (31) for controlling the second wire feeding means (35).
    Type: Grant
    Filed: August 14, 2012
    Date of Patent: November 27, 2018
    Assignee: ESAB AB
    Inventors: Hannes Raudsepp, Martin Andersson, Tomas Johansson, Rikard Ljungkvist
  • Publication number: 20150273614
    Abstract: A method comprising an arc ignition phase (IP), an arc-stabilizing phase (AP) and a stable arc phase (SP). The arc stabilizing phase comprises an initial sub-phase (IS) comprising the step of feeding at least one hot wire (4, 12) at constant feed speed and a main sub-phase (MS) comprising the steps of feeding said hot wire at constant feed speed and feeding at least one cold wire (22) at constant feed speed. The stable arc phase comprises the steps of continuously adjusting the feed speed of the hot wire and continuously adjusting the feed speed of the cold wire. The invention also relates to a welding apparatus (1) for carrying out the method. The welding apparatus comprises a hot wire feeding means (150), a contact means (2), a cold wire feeding means (35) and a control unit (31).
    Type: Application
    Filed: November 2, 2012
    Publication date: October 1, 2015
    Inventors: Hannes Raudsepp, Martin Andersson, Tomas Johansson, Rikard Ljungkvist
  • Publication number: 20150202709
    Abstract: The invention relates to a method for submerged arc welding comprising the steps of guiding a first hot wire (4; 4a, 4b) towards a work piece and guiding a cold wire (22; 22a, 22b) at a variable feed speed. The method further comprises the steps of continuously measuring, during a welding phase, at least a first active welding parameter related to at least said first hot wire (4; 4a, 4b) adjusting the cold wire (22; 22a, 22b) feed speed in dependence on at least first active welding parameter variations, to maintain high welding stability and high weld quality. The invention also relates to a system (9) for carrying out the method. The system (9) comprises hot wire feeding means (150) for feeding a first hot wire (4; 4a, 4b) towards a work piece and cold wire feeding means (35) for feeding a cold wire (22; 22a, 22b) at a variable cold wire (22; 22a, 22b) feed speed and a control unit (31) for controlling the second wire feeding means (35).
    Type: Application
    Filed: August 14, 2012
    Publication date: July 23, 2015
    Applicant: ESAB AB
    Inventors: Hannes Raudsepp, Martin Andersson, Tomas Johansson, Rikard Ljungkvist