Patents by Inventor Lutz Seffner

Lutz Seffner 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: 8297133
    Abstract: A pressure sensor has a multiplicity of piezoelectric converter elements which are arranged such that they are essentially parallel to a force-applying or pressure-applying direction. The converter elements can be arranged at a distance from one another by an insulating material and/or are at least partially embedded in the material. A support material having greater mechanical rigidity than the converter elements, in particular in the force-applying or pressure-applying direction, is assigned to at least a number of piezoelectric converter elements, or the piezoelectric converter element is applied, in the form of a layer, to a supporting body made from this support material and is electrically contact-connected, for example, by a bottom electrode, which is arranged between the converter element layer and the supporting body, and a cover electrode which is applied to an outer side of the converter element layer.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: October 30, 2012
    Assignees: S.W.A.C. Schmitt-Walter Automation Consult GmbH, Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung E.V.
    Inventors: Stefan Schmitt-Walter, Lutz Seffner, Thomas Roedig, Sylvia Gebhardt, Bent Brueckner, Andreas Schoenecker
  • Publication number: 20100011884
    Abstract: A pressure sensor has a multiplicity of piezoelectric converter elements which are arranged such that they are essentially parallel to a force-applying or pressure-applying direction. These can be in the form of fibres, small rods, plates or the like, and may also be in the form of a thick or thin layer. When the converter elements are in the form of fibres, small rods or plates, they are arranged at a distance from one another by means of an insulating material and/or are at least partially embedded in said material.
    Type: Application
    Filed: June 20, 2005
    Publication date: January 21, 2010
    Inventors: Stefan Schmitt-Walter, Lutz Seffner, Thomas Roedig, Sylvia Gebhardt, Bent Brueckner, Andreas Schoenecker
  • Patent number: 7228606
    Abstract: A method of manufacturing a piezoelectric transducer including piezoelectric fibers in a polymer matrix is described. The piezoelectric fibers or fiber segments are jacketed with a liquid polymer substance in such a way that a distribution of longitudinal axes of the fibers or fiber segments about a preferential direction occurs. The fibers are compacted among each other and the polymer substance is cured. The resulting composite structure is subsequently so processed that areas of the fibers or fiber segments are exposed along the preferential direction. Then electrical contacts are applied on at least one part of the exposed areas. The method permits the very simple and low-cost manufacture of electro-mechanical transducers made of piezoelectric fibers.
    Type: Grant
    Filed: October 12, 2000
    Date of Patent: June 12, 2007
    Assignee: Fraunhofer-Gesellschaft zur Forderung der Forschung e.V.
    Inventors: Lutz Seffner, Andreas Schönecker, Sylvia Gebhardt
  • Patent number: 6337835
    Abstract: The present invention relates to an electromechanical converter, a method of manufacturing same, as well as to a composite system including the electromechanical converter. The inventive electromechanical converter consists of at least one elongate fiber (1) made of a piezoelectric material. At least two electrodes (2) are provided at mutually spaced locations on the fiber (1) for subjecting the fiber to an electrical field. The electrodes (2) are in direct contact with the fiber (1) and enclose the fiber (1) partly or completely. The direct contact between the electrode and the fiber permits the optimum introduction of the electrical field into the fiber such that lower electrical potentials on the electrodes are sufficient for polarising the fiber. Another advantage resides in the aspect that the electrode is in direct contact with the fiber not only at one point but over part of the periphery of the fiber. This results in a further enhancement of the introduction of the electrical field.
    Type: Grant
    Filed: March 15, 2000
    Date of Patent: January 8, 2002
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Dieter Sporn, Winfried Watzka, Andreas Schönecker, Lutz Seffner, Kord Pannkoke
  • Patent number: 5786048
    Abstract: A ferroelectric ceramic material, for the storage of information in electrostatic printing processes, which ferroelectric ceramic material has a coercive force of less than 200 V/mm. The ferroelectric ceramic material consists of a ceramic perovskitic mixed crystal, which contains one or more components from each of Groups 1 and 2, whereby Group 1 contains the components PbTiO.sub.3, BaTiO.sub.3, Pb(Fe.sub.1/2 Nb.sub.1/2)O.sub.3 and Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 and Group 2 contains the components Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3, Pb(Ni.sub.1/3 Nb.sub.2/3)O.sub.3, Pb(Fe.sub.2/3 W.sub.1/3)O.sub.3 and Pb(Mn.sub.1/2 Nb.sub.1/2)O.sub.3. The proportions of the components from the two groups in the mixed crystal are determined according to the following equation: ##EQU1## where X.sub.i is the mole fraction of the i-component, T.sub.ci is the Curie point of the i-component and T.sub.cM is the Curie point of the mixture between 50.degree. C. and 100.degree. C.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: July 28, 1998
    Assignee: Man Roland Druckmaschinen AG
    Inventors: Hans-Jurgen Gesemann, Lutz Seffner, Andreas Schonecker, Falko Schlenkrich
  • Patent number: 5501876
    Abstract: A process for producing PZT films on a substrate by thick-film technique in which the PZT films contain simply modified PZT and/or PZT with complex perovskite. PZT with a Zr content X of X.gtoreq.X.sub.p +0.02.ltoreq.X.sub.p +0.10 is used, where X.sub.p is the Zr content of the base composition at the morphotropic phase boundary determined by the maximum coupling factor K.sub.r.
    Type: Grant
    Filed: July 27, 1994
    Date of Patent: March 26, 1996
    Assignee: MAN Roland Druckmaschinen AG
    Inventors: Hans-Ju/ rgen Gesemann, Lutz Seffner, Karin Vo/ lker