Patents by Inventor Hans A. Graefe

Hans A. Graefe 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: 5581856
    Abstract: Uncoated technical fabric is produced in a dense weave with low air permeability. The fabric contains polyamide filament yarns with a hot air shrinkage of 6 to 15% (determined at 160.degree. C.) and has an at least substantially symmetrical fabric construction. The fabric is adjusted to the required air permeability by a treatment in an aqueous bath at 60.degree. to 140.degree. C.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: December 10, 1996
    Assignee: Akzo N.V.
    Inventors: Wolf Krummheuer, Hans A. Graefe, Volker Siejak
  • Patent number: 5554424
    Abstract: To manufacture airbags comprising a contact fabric and/or a filter fabric it is proposed to use hollow fiber synthetic filament yarns having a hollow area fraction of 10-40%, based on the total cross-sectional area of the fiber. The closeness values are >72% for the contact fabric and 45-68% for the filter fabric. In addition to reducing the production costs, hollow fibers also make it possible to produce lighter fabrics. These have a beneficial effect on the working of an airbag.
    Type: Grant
    Filed: April 25, 1995
    Date of Patent: September 10, 1996
    Assignee: Akzo Nobel, N.V.
    Inventors: Wolf R. Krummheuer, Volker Siejak, Hans Graefe
  • Patent number: 5508073
    Abstract: Uncoated, tightly woven, synthetic filament yarn fabric for manufacturing an air bag. The fabric is manufactured from polyamide yarns having a filament linear density of less than 4 dtex. The air permeability of this fabric is <10 l/dm.sup.2 .multidot.min and its specific stiffness is <1.0.times.10.sup.-2.
    Type: Grant
    Filed: August 27, 1993
    Date of Patent: April 16, 1996
    Assignee: Akzo NV
    Inventors: Wolf R. Krummheuer, Dieter Kaiser, Hans A. Graefe, Volker Siejak
  • Patent number: 5477890
    Abstract: In a method of manufacturing uncoated industrial woven fabrics having specifically adjusted air permeability from synthetic fibers, after the synthetic fibers have been woven into a fabric the fabric is passed through an aqueous bath having a temperature of approximately 20.degree.-100.degree. C., then is passed through a drying zone. The woven fabric is allowed to shrink in the aqueous bath and in the subsequent drying zone to produce a woven fabric having a specific air permeability. The method is especially suitable for the manufacture of fabric used in air bags.
    Type: Grant
    Filed: July 28, 1994
    Date of Patent: December 26, 1995
    Assignee: Akzo Nobel NV
    Inventors: Wolf R. Krummheuer, Volker Siejak, Hans A. Graefe
  • Patent number: 5356680
    Abstract: Industrial fabrics have controlled air permeability <120 l/dm.sup.2 .times. min and a very good ageing resistance. The air permeability value does not change by more than 15% in the ageing test. This fabric can be made by adapting production conditions for weaving, wet processing, and in particular, hot air treatment. The process is particularly suited for manufacturing air bag fabrics.
    Type: Grant
    Filed: July 16, 1992
    Date of Patent: October 18, 1994
    Assignee: Akzo N.V.
    Inventors: Wolf R. Krummheuer, Hans A. Graefe, Volker Siejak
  • Patent number: 5131434
    Abstract: An air bag fabric has zones of differing air permeability which are variable in shape and size. A dobby, tappet or Jacquard machine may be used to weave, into a fabric having tight basic weave, window-like zones with a weave which differs from the basic weave, as a result of which these zones have a high air permeability. The zones of low air permeability are arranged in such a way that later they form the edges of cuts and seams. It is further possible to manufacture fabrics which have zones of differing air permeability by alternating sections of high warp or weft sett with sections of low warp or weft sett. The fabrics of the invention are suitable in particular for the filter part of air bags.
    Type: Grant
    Filed: September 9, 1991
    Date of Patent: July 21, 1992
    Assignee: Akzo N.V.
    Inventors: Wolf R. Krummheuer, Hans A. Graefe, Volker Siejak
  • Patent number: 5093163
    Abstract: A heat shrinkable uncoated fabric of synthetic filament yarn for the production of airbags is produced with an at least substantially symmetric fabric contruction. A yarn with a titre of 300-400 dtex is used.
    Type: Grant
    Filed: September 6, 1990
    Date of Patent: March 3, 1992
    Assignee: Akzo N.V.
    Inventors: Wolf Krummheuer, Hans A. Graefe, Volker Siejak