Patents by Inventor Elmar Schäfers

Elmar Schäfers 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: 7421922
    Abstract: A device for linearly moving a useful mass is described. Typically, when a large useful mass is moved, relatively large forces are transferred by a spindle or a toothed rack to the corresponding machine or machine frame. These forces can be compensated by moving a compensating mass in the opposite direction of the useful mass.
    Type: Grant
    Filed: February 20, 2004
    Date of Patent: September 9, 2008
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jens Hamann, Elmar Schäfers, Bernd Wedel
  • Patent number: 7208901
    Abstract: A control method for controlling a speed of a movable machine element of a numerically controlled industrial processing machine with jerk limitation is described. The processing machine can be, for example, a machine tool, a production machine and/or a robot. A travel path of the movable machine element is first decomposed into a plurality of sequentially arranged, interpolatable travel sections. Jerk profiles are then determined for the interpolatable travel sections, which are modified with a parameter-dependent shape function. The modified jerk profiles provide a filter action that can be represented by bandpass filters having blocking frequencies. The blocking frequencies of the bandpass filters are selected so as to substantially correspond to characteristic frequencies of the machine element. The control method significantly improves the machine dynamics without sacrificing accuracy.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: April 24, 2007
    Assignee: Siemens Aktiengesellschaft
    Inventors: Uwe Ladra, Elmar Schäfers
  • Patent number: 7152503
    Abstract: A device for compensating a torque produced on a movable axle in a machine tool or production machine by a gyrostatic effect includes a rotating useful machine system attached to the movable axle and producing a useful angular momentum, and a rotating machine counter-system attached to the axle and producing a counter angular momentum. The magnitude of the counter angular momentum is substantially identical to the magnitude of the useful angular momentum. The useful torque produced by a movement of the rotating useful machine system through a temporal change of the useful angular momentum is at least partially compensated by a counter-torque produced by a temporal change of the counter angular momentum. This arrangement represents a simple device for compensating a torque produced by the gyrostatic effect on a movable axle of machine tolls and production machines.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: December 26, 2006
    Assignee: Siemens Aktiengesellschaft
    Inventors: Gerhard Forster, Winfried Glück, Jens Hamann, Uwe Ladra, Elmar Schäfers, Dietmar Stoiber, Hans-Peter Tröndle, Bernd Wedel
  • Patent number: 6979932
    Abstract: Parallel kinematics with rod guidance are nowadays used in machine tools, production machines and robotics. Changes in rod length caused by the special position of the moving work platform (P), by its acceleration and other force impact, can lead to positional errors. Such errors are eliminated by means of piezo-actuators (PA1–PA6) which are integrated into the rods (S1 to S6).
    Type: Grant
    Filed: May 17, 2002
    Date of Patent: December 27, 2005
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jens Hamann, Uwe Ladra, Elmar Schäfers
  • Patent number: 6940247
    Abstract: The PDT2 filtering element (PDT2) and a Cauer filter (C2) are employed for use in control tasks of automation engineering, in particular for a filter connected downstream of a rotational speed controller. For tasks in control engineering, these have the advantage of a higher level of robustness, since a large frequency range is filtered, and a substantially smaller phase drop than conventional lowpass filters (PDT2). Consequently, by comparison with the known prior art a loss in dynamics is substantially minimized with these phase-saving lowpass filters, and an optimum is achieved in robustness and dynamics.
    Type: Grant
    Filed: July 31, 2001
    Date of Patent: September 6, 2005
    Assignee: Siemens Aktiengesselschaft
    Inventors: Elmar Schaefers, Hans-Peter Troendle
  • Patent number: 6903529
    Abstract: Damping of mechanical oscillation in a shaft that is provided by feedback wherein the output signals of multiple feedback devices are negatively coupled and added to a desired speed signal of a motor speed controller of the driving motor is disclosed. At least one sensor and/or measuring system can be provided for measuring an actual position value. The actual speed of the shaft can be determined by differentiation from the shaft position value measurements or by integration from shaft acceleration measurements. The measured or actual speed of the shaft can be supplied as an input signal to each feedback element. Each feedback element is specifically tuned to an oscillation frequency range of the shaft that is to be damped. The invention provides an easy and cost-effective way of damping mechanical oscillations that have limited frequency ranges.
    Type: Grant
    Filed: October 1, 2003
    Date of Patent: June 7, 2005
    Assignee: Siemens Aktiengesellschaft
    Inventors: Stefan Künzel, Theo Reichel, Elmar Schäfers, Andreas Uhlich
  • Patent number: 6825633
    Abstract: The excitation of an oscillation in a mechanical system, such as a machine element, subjected to a jerk can be suppressed or at least attenuated by rounding a corresponding jerk curve and/or by tuning the stop band of a bandstop filter to the characteristic frequencies of the mechanical system or machine element. In combination, both measures can improve the positioning accuracy while at the same time minimizing excitation of oscillations.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: November 30, 2004
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jens Hamann, Uwe Ladra, Elmar Schäfers
  • Patent number: 6769902
    Abstract: In an injection-molding machine, the rapid traversing over long distances takes place with the aid of linear drives (L1, L2), the “rotor” (H1, H2) which is a component part of the machine construction.
    Type: Grant
    Filed: August 14, 2001
    Date of Patent: August 3, 2004
    Assignee: Siemens Aktiengesellschaft
    Inventors: Jens Hamann, Elmar Schaefers
  • Patent number: 6580245
    Abstract: A critical resonant frequency (fres) of the axes of a moving machine element is damped as effectively as possible with the aid of a jerk limitation. Good damping in the case of a desired frequency is achieved when the longest possible time (TrLim) which can be traveled with a maximum permissible jerk (rLim) is selected such that 1/TrLim coincides with the lowest natural frequency (fres) of the participating axes. This finding is implemented by adapting the path dynamics such that the TrLim=aMax/rLim yielded by the prescribed dynamics limiting values is varied by reducing the maximum jerk (rLim) to achieve good damping results for the lowest natural frequency (fres) of the participating axes.
    Type: Grant
    Filed: August 14, 2001
    Date of Patent: June 17, 2003
    Assignee: Siemens Aktiengesellschaft
    Inventors: Bernd Quaschner, Theo Reichel, Elmar Schaefers, Wilhelm Westermeyer, Georg Wiegaertner
  • Publication number: 20020140394
    Abstract: The PDT2 filtering element (PDT2) and a Cauer filter (C2) are employed for use in control tasks of automation engineering, in particular for a filter connected downstream of a rotational speed controller. For tasks in control engineering, these have the advantage of a higher level of robustness, since a large frequency range is filtered, and a substantially smaller phase drop than conventional lowpass filters (PDT2). Consequently, by comparison with the known prior art a loss in dynamics is substantially minimized with these phase-saving lowpass filters, and an optimum is achieved in robustness and dynamics.
    Type: Application
    Filed: July 31, 2001
    Publication date: October 3, 2002
    Inventors: Elmar Schaefers, Hans-Peter Troendle
  • Publication number: 20020074964
    Abstract: The goal of the invention is to dampen as effectively as possible a critical resonant frequency (fres) of the axes of a moving machine element with the aid of a jerk limitation. Good damping in the case of a desired frequency is achieved when the longest possible time (TrLim) which can be traveled with a maximum permissible jerk (rLim) is selected such that 1/TrLim coincides with the lowest natural frequency (fres) of the participating axes. The present invention attempts to convert this finding by adapting the path dynamics by virtue of the fact that the TrLim=aMax/rLim yielded by the prescribed dynamics limiting values is varied by reducing the maximum jerk (rLim) such that good damping results for the lowest natural frequency (fres) of the participating axes.
    Type: Application
    Filed: August 14, 2001
    Publication date: June 20, 2002
    Inventors: Bernd Quaschner, Theo Reichel, Elmar Schaefers, Wilhelm Westermeyer, Georg Wiegaertner
  • Publication number: 20020058083
    Abstract: In an injection-molding machine, the rapid traversing over long distances takes place with the aid of linear drives (L1, L2), the “rotor” (H1, H2) which is a component part of the machine construction.
    Type: Application
    Filed: August 14, 2001
    Publication date: May 16, 2002
    Inventors: Jens Hamann, Elmar Schaefers