Patents by Inventor Siegfried Doujak

Siegfried Doujak 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: 7188653
    Abstract: A first aspect of the present invention relates to a filament (11; 12), especially for reinforcing rubber articles. Said filament (11; 12) features a contact surface (14) and an outer surface (13). In a second aspect, the invention relates to a steel cord (10) comprising two of said filaments (11, 12), the contact surfaces (14) are arranged adjacent to each other. The outer surfaces (13) are configured arcuate shaped and provide a smooth outer contour (15) of the steel cord (10). Due to said construction the largest dimension (d) of the steel cord (10) and the thickness of a rubber coating (18) may be considerably reduced. Additionally the invention relates to a method of producing a steel cord (10) and to a tyre (20) comprising a carcass ply (22) and/or at least one belt (25; 26) including said steel cords (10).
    Type: Grant
    Filed: October 11, 2001
    Date of Patent: March 13, 2007
    Assignee: Drahtcord Saar GmbH & Co., KG
    Inventor: Siegfried Doujak
  • Publication number: 20050098253
    Abstract: A first aspect of the present invention relates to a filament (11; 12), especially for reinforcing rubber articles. Said filament (11; 12) features a contact surface (14) and an outer surface (13). In a second aspect, the invention relates to a steel cord (10) comprising two of said filaments (11, 12), the contact surfaces (14) are arranged adjacent to each other. The outer surfaces (13) are configured arcuate shaped and provide a smooth outer contour (15) of the steel cord (10). Due to said construction the largest dimension (d) of the steel cord (10) and the thickness of a rubber coating (18) may be considerably reduced. Additionally the invention relates to a method of producing a steel cord (10) and to a tyre (20) comprising a carcass ply (22) and/or at least one belt (25; 26) including said steel cords (10).
    Type: Application
    Filed: October 11, 2001
    Publication date: May 12, 2005
    Inventor: Siegfried Doujak
  • Patent number: 6681555
    Abstract: The invention relates to a false twister (10), especially for producing spiral filaments. The false twister comprises a rotatably driven twister (17) with at least one guide roller (18) around which the filaments (11) are wrapped. The aim of the invention is to reduce the forces that act upon the spiral filaments (11′). To this end, at least one guide roller (18) is driven. According to a method for producing spiral filaments (11) the power necessary for moving the filaments (11) through the false twister (10) is at least partially applied on the filaments (11) in the false twister (10).
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: January 27, 2004
    Assignee: Drahtcord Saar GmbH & Co. KG
    Inventors: Bernd Heisel, Siegfried Doujak
  • Patent number: 6602614
    Abstract: A brass coated metallic wire for use as a reinforcing component in an elastomeric article, such as a motor vehicle tire. The brass coating is formed by depositing alternate layers of copper and zinc on the wire and then drawing the wire under conditions of temperature and pressure suitable to alloy the copper and zinc to form a brass coating on the wire.
    Type: Grant
    Filed: July 25, 2002
    Date of Patent: August 5, 2003
    Assignee: Pirelli Pneumatici S.p.A.
    Inventors: Siegfried Doujak, Federico Pavan, Andrea Pieralli
  • Publication number: 20030003319
    Abstract: A brass coated metallic wire for use as a reinforcing component in an elastomeric article, such as a motor vehicle tire. The brass coating is formed by depositing alternate layers of copper and zinc on the wire and then drawing the wire under conditions of temperature and pressure suitable to alloy the copper and zinc to form a brass coating on the wire.
    Type: Application
    Filed: July 25, 2002
    Publication date: January 2, 2003
    Applicant: Pirelli Pneumatici S.p.A., Viale Sarca
    Inventors: Siegfried Doujak, Federico Pavan, Andrea Pieralli
  • Patent number: 6475640
    Abstract: A brass coated metallic wire for use as a reinforcing component in an elastomeric article, such as a motor vehicle tire. The brass coating is formed by depositing alternate layers of copper and zinc on the wire and then drawing the wire under conditions of temperature and pressure suitable to alloy the copper and zinc to form a brass coating on the wire.
    Type: Grant
    Filed: October 27, 1999
    Date of Patent: November 5, 2002
    Assignee: Pirelli Pneumatici S.p.A.
    Inventors: Siegfried Doujak, Federico Pavan, Andrea Pieralli
  • Patent number: 6151879
    Abstract: For reinforcing rubber or plastics articles, particularly pneumatic tires, a wire filament is proposed which is spirally shaped and exhibits no elastic residual torsional stresses. A wire filament 8 according to the invention is produced by twisting drawn straight wire filaments 2 into the range of plastic deformation with subsequent return-twisting, at least two wire filaments being brought together and combined prior to return-twisting. Preferably at least two wire filaments 2 are brought together by means of a perforated disk 30, twisted about each other and plastically deformed in a false twister 20 and subsequently return-twisted in a further false twister 40.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: November 28, 2000
    Assignee: Drahtcord Saar GmbH & Co. KG
    Inventor: Siegfried Doujak
  • Patent number: 6076344
    Abstract: Process for producing a steel cord for pneumatic tires comprising a bunch of wires, the core of which consists of wire filaments 10 arranged bunched juxtaposed in parallel. Preferably at least three wire filaments 10, 20 are provided, at least two wire filaments located juxtaposed in parallel being spirally shaped as core filaments 10 forming a core 60 and at least one wire filament spirally surrounding the two core filaments 10 as a sheathing wire 20. Spirally shaping the wire filaments 10 is achieved in accordance with the invention by false twisters 40. Due to this spiral shaping of the wire filaments 10 migration of the filaments from the core composite is avoided more particularly. The residual torsional stresses of the core filaments among each other and in conjunction with the restoring forces of the sheathing wire are advantageously cancelled. In addition, the steel cord features to advantage a flattened, more particularly, oval shape.
    Type: Grant
    Filed: July 17, 1998
    Date of Patent: June 20, 2000
    Assignee: Drahtcord Saar GmbH & Co. KG
    Inventor: Siegfried Doujak
  • Patent number: 6007912
    Abstract: A wire cord for reinforcing rubber items, more particularly pneumatic tires for cars and trucks, comprises at least three wire filaments 2 arranged about a continuous core filament 3. The core filament 3 consists of a non-metallic material capable of longitudinal contraction when the rubber item 5 to be reinforced is vulcanized, this material being more particularly non-drawn nylon. On vulcanization of the rubber item 5 to be reinforced the core filament 3 contracts and expands in diameter.
    Type: Grant
    Filed: May 22, 1998
    Date of Patent: December 28, 1999
    Assignee: Drahtcord Saar GmbH & Co.
    Inventor: Siegfried Doujak