Patents by Inventor Rolf Karlsson

Rolf Karlsson 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: 20220324049
    Abstract: A method includes supplying a welding current to a welding zone, monitoring, during a welding current ramp down period of a given short arc welding process cycle, a voltage across a current braking switch that is in an open state and that causes a decrease in welding current being supplied to a welding zone; and when the voltage across the current braking switch that is in the open state reaches a first predetermined voltage threshold, closing the current braking switch before a completion of the welding current ramp down period of the given short arc welding process cycle.
    Type: Application
    Filed: April 13, 2021
    Publication date: October 13, 2022
    Inventor: Rolf Karlsson
  • Publication number: 20220274198
    Abstract: A method includes ramping down a welding current, generated by a power supply, that reaches a welding zone via a welding circuit, storing inductive energy from the welding circuit that is generated as a result of the ramping down to obtain stored energy, and selectively feeding the stored energy to the welding circuit.
    Type: Application
    Filed: March 1, 2021
    Publication date: September 1, 2022
    Inventor: Rolf Karlsson
  • Patent number: 8254150
    Abstract: An inverter provides alternating current (iout) to a load (130) containing a welding circuit. The inverter includes at least one commutation circuit (110) and a bridge circuit (120) connected to a bus forwarding power from a DC power source (100). The bus is also galvanically connected to the load (130) via the bridge circuit (120). The at least one commutation circuit (110) receives power from the DC power source (100); receives energy from inductive elements in the load (130) during a storage phase of a cyclic procedure, and controls energy feedback to the load (130) during a feedback phase of the cyclic procedure. The at least one commutation circuit (110) is a two-pole having a first pole (p1) connected to a first node (A) and a second pole (p2) connected to a second node (B). The at least one commutation circuit (110) is arranged to receive energy from the load (130) and feedback energy to the load (130) via the first and second nodes (A; B), either directly or via the bridge circuit (120).
    Type: Grant
    Filed: September 14, 2009
    Date of Patent: August 28, 2012
    Assignee: ESAB AB
    Inventors: Rolf Karlsson, Per Andersson, Dan Wessman
  • Publication number: 20120195086
    Abstract: An inverter provides alternating current (iout) to a load (130) containing a welding circuit. The inverter includes at least one commutation circuit (110) and a bridge circuit (120) connected to a bus forwarding power from a DC power source (100). The bus is also galvanically connected to the load (130) via the bridge circuit (120). The at least one commutation circuit (110) receives power from the DC power source (100); receives energy from inductive elements in the load (130) during a storage phase of a cyclic procedure, and controls energy feedback to the load (130) during a feedback phase of the cyclic procedure. The at least one commutation circuit (110) is a two-pole having a first pole (p1) connected to a first node (A) and a second pole (p2) connected to a second node (B). The at least one commutation circuit (110) is arranged to receive energy from the load (130) and feedback energy to the load (130) via the first and second nodes (A; B), either directly or via the bridge circuit (120).
    Type: Application
    Filed: September 14, 2009
    Publication date: August 2, 2012
    Applicant: ESAB AB
    Inventors: Rolf Karlsson, Per Andersson, Dan Vessman
  • Patent number: 6666338
    Abstract: A device for the separation of solid objects (9) from fluid flowing in a conduit tube (2) includes a housing that includes a tubular outer wall (3) and a tubular inner wall (4). Between these is delimited a collecting space (8). Concentrically relative to the inner wall (4) is provided a rotation-symmetrical central body (12) which at opposing ends cooperates with flow converting devices (15, 16), which transform incoming flow to a rotative motion and outgoing flow to an axial motion. In the inner wall (4) are recessed tangentially separated holes (20) of elongated shape, through which the scrap objects may pass and be collected in a collecting space (8). In the collecting space (8) a calm flow operation is obtained which guarantees that collected scrap objects are not carried away and returned to the main fluid flow through the separation device.
    Type: Grant
    Filed: September 14, 2001
    Date of Patent: December 23, 2003
    Assignee: Vattenfall AB
    Inventors: Mats Henriksson, Anders Lundström, Rolf Karlsson, Tapio Kaipanen, Johan Westin
  • Patent number: 6423937
    Abstract: The invention relates to an arrangement for contact arc ignition in manual TIG welding and to a method for welding with this arrangement. The arc is established by lifting the welding torch (12) after contact between electrode (13) and workpiece (14) under low ignition current. When the arc length is sufficient, the welder orders a change-over to welding current via an operating device (11). The invention can also be used for controlling the supply of heat to the workpiece both during continuous bead application and during the crater filling time at the end of welding. The invention creates reliable ignitions without extensive use of control electronics, and it substantially reduces the electrode wear in manual TIG welding.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: July 23, 2002
    Assignee: Esab AB
    Inventor: Rolf Karlsson
  • Patent number: 6316745
    Abstract: The invention relates to an arrangement for material transport and/or energy transport by means of electric arc. Measured values are transferred with suppression of disturbances from the HF device (2) without appreciable damping of the HF voltage to the electrode (14). A measurement winding (16) is arranged together with a power winding (8) in such a way that effective suppression of disturbances is achieved. Examples of areas of application are thermal spraying, cutting and welding, in particular mechanized TIG welding, but the invention is principally indicated in cases where a spark is established with HF voltage across a gap filled with a gas or a gas/liquid mixture and where at the same time some parameter has to be measured in connection with the spark gap.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: November 13, 2001
    Assignee: ESAB AB
    Inventor: Rolf Karlsson
  • Patent number: 6017171
    Abstract: The invention relates to a process for the production of a milling tool for cutting machining, preferably of metals. The milling tool includes a holder part (2) for the fixation of the milling tool upon a rotating driving arrangement, and an insert carrying part which around its periphery is equipped with several detachable cutting inserts (23), each cutting insert being fastened in an insert seat, which at least partly is situated in a peripheral, insert-carrying milling tool portio (12). Each insert seat includes a bottom support surface (10) and a side support including at least one side support surface (9), a chip pocket (25) being provided in front of each insert seat in the direction of rotation. The side support of the insert seat at least partly is made by a ball-nose end mill (8). This brings about that the number of insert seats in a milling tool may be substantially increased.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: January 25, 2000
    Assignee: Sandvik Aktiebolag
    Inventor: Rolf Karlsson
  • Patent number: 5944273
    Abstract: A uniformly wound parent roll of soft, high bulk tissue has greater uniformity in sheet basis weight, machine direction stretch and bulk when compared to parent rolls wound by conventional winding methods. The method involves carrying the tissue sheet on a relatively air impermeable transfer belt which traverses an unsupported span between two winding drums. The sheet is transferred from the transfer belt to the parent roll as the parent roll is urged against the sheet/transfer belt at a point within the unsupported span. The resulting deflection of the transfer belt is detected and, in response, the reel spool position is controllably changed to maintain the deflection within predetermined limits. The tension of the sheet is controlled by the predetermined differential speed between the outer most surface of the parent roll and the transfer belt.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: August 31, 1999
    Assignee: Kimberly-Clark Worldwide, Inc.
    Inventors: Philip Sim Lin, Randall James LeValley, Brian Douglas Klaubert, Ronald Frederick Gropp, Tommy Rolf Karlsson, Bernt Erik Ingvar Klerelid
  • Patent number: 5901918
    Abstract: An apparatus and method for winding tissue webs into a parent roll is disclosed which results in greater uniformity in sheet basis weight, machine direction stretch and bulk when comparing the corresponding sheet properties taken from representative locations throughout the roll. The apparatus and method includes engaging the tissue web against a reel spool with a flexible member such as a transfer belt which traverses an unsupported span between two support rolls. The web is transferred from the transfer belt to the parent roll as the parent roll is urged against the sheet/transfer belt at a point within the unsupported span. The resulting deflection of the transfer belt is detected and, in response, the reel spool position is changed to control the deflection at a desired level. Accordingly, a predetermined light nip pressure can be applied to the roll as the tissue web is wound thereon and large parent rolls of high bulk tissue can be manufactured with desired properties when unwound.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: May 11, 1999
    Assignee: Valmet-Karlstad AB
    Inventors: Bernt Erik Ingvar Klerelid, Tommy Rolf Karlsson, Randall James Le Valley, Ronald Frederick Gropp, Philip Sim Lin, Brian Douglas Klaubert
  • Patent number: 5534144
    Abstract: A unit for treating liquid comprises a cylindrical container (1) which, in an upper chamber (6), has a set of slender tubes (8) which the liquid is forced to pass on its way from an inlet (10) to an outlet (9), so as to be subjected to a treatment, such as deionization, during this forced passage. An annular casing (11) is arranged in a lower chamber (7) and serves to distribute the liquid flowing in through the inlet (10). The casing (11) is defined by inner and outer side walls (12, 13) sealingly interconnected along an upper edge portion (14) as well as interconnected by at least one lower, transverse wall (15) which is provided with a plurality of small holes through which the liquid is squeezed out in the form of a large number of individual jets. The cross-sectional area of the liquid-distributing casing (11) continuously decreases away from the inlet (10) towards an opposite end (18) of the casing.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: July 9, 1996
    Assignee: Vattenfall Utveckling AB
    Inventors: Bengt Hemstrom, Johan Persson, Rolf Karlsson
  • Patent number: 5492409
    Abstract: A device for mixing two fluids having different temperatures comprises a connecting branch (6) extending into a main pipe (1) from a secondary pipe (2), said connecting branch having at its end positioned in the main pipe a distribution casing (7) with double annular walls, of which an inner wall (9) defines a channel (10) extending axially and centrally in the main pipe (1), and having apertures which allow a fluid (B) to be conducted into and mixed with the fluid (A) passing through the main pipe. The apertures consist of a plurality of small apertures (11) which are formed in the inner wall (9) of the distribution casing (7) and provide intermixing of the two fluids directly in the channel (10) positioned centrally in the main pipe (1).
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: February 20, 1996
    Assignee: Vattenfall Utveckling AB
    Inventors: Rolf Karlsson, Hernan Tinoco, Mats Henriksson, Anders Lundstrom