Patents by Inventor Ernst Schwefel

Ernst Schwefel 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: 5001340
    Abstract: An interferometric type photoelectric measuring device is disclosed. The photoelectric angle measuring device includes a graduation carrier having a circular graduation and a scanning arrangement for the diametral scanning of the circular graduation. The scanning arrangement is constructed as an integrated optical circuit.
    Type: Grant
    Filed: October 24, 1989
    Date of Patent: March 19, 1991
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventors: Ernst Schwefel, Dieter Michel, Olivier Pariaux
  • Patent number: 4760280
    Abstract: A process and apparatus for improving the resolution of square, subdivided signals by synchronizing the signals with an auxiliary clock signal. The signals are further conditioned by switching logic elements which, in dependence upon adjacent signals in the subdivision order and upon the auxiliary clock signal, only allow the states of the signals to change at predefined times.
    Type: Grant
    Filed: June 18, 1986
    Date of Patent: July 26, 1988
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventors: Ernst Schwefel, Martin Huber, Alois Zimmermann
  • Patent number: 4575791
    Abstract: A method for restarting a tool on a workpiece contour in a numerically controlled processing machine of the type having a display unit for alphanumerical and/or graphical representation of processing information. After a program interruption, the program is executed anew in a control mode without machine movement from a predetermined starting point, and the resulting workpiece contour is continuously, graphically represented on the display unit. The operator utilizes this graphic display to determine an end point of the control mode program execution. The machine is then transferred into its axial positions and its function state to the program state of the end point, and the processing program with machine movements is continued from this end point, thereby starting the tool onto the desired tool path.
    Type: Grant
    Filed: March 20, 1984
    Date of Patent: March 11, 1986
    Assignee: Johannes Heidenhain GmbH
    Inventor: Ernst Schwefel
  • Patent number: 4564912
    Abstract: A control system for a processing machine such as an eroding machine operates to determine preferred withdrawal directions between a workpiece and a tool. In addition to the path movements necessary for the treatment process, the control system determines in advance at each point along the predetermined path a withdrawal direction oriented away from the surface being processed. This withdrawal direction runs essentially normal or perpendicular to the surface being processed on the workpiece. The amount of the desired separation between the tool and the workpiece along the withdrawal path is applied as an input to the control system in accordance with predetermined parameters of the treatment process.
    Type: Grant
    Filed: August 2, 1985
    Date of Patent: January 14, 1986
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Ernst Schwefel
  • Patent number: 4521845
    Abstract: A control device for a numerically controlled machine tool includes both on/off and continuously variable switches which are coupled via a computer to associated machine functions such as coolant flow or feed rate. The computer is programmed to operate in any one of three modes. In the first mode the manually controlled input switches are read by the computer during computer-controlled processing of a first workpiece according to processing information stored in memory, the computer stores information regarding the state of the switches for later use, and also controls the machine functions to correspond with the current state of the input switches. In the second mode the computer controls the machine functions during computer-controlled processing of subsequent workpieces in accordance with previously stored information, independently of the current position of the input switches.
    Type: Grant
    Filed: June 22, 1981
    Date of Patent: June 4, 1985
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Ernst Schwefel
  • Patent number: 4517657
    Abstract: A freely programmable control system is disclosed which includes a computer, a data memory, and a program memory, as well as a program controllable logical network for individual bit processing and an individual bit memory. The disclosed control system operates as an integrated system which utilizes both commands for the computer and separate commands for individual bit processing. Both types of commands are stored in the program memory as an integrated program. During individual bit processing the commands for the individual bit operations are routed from the program memory to the logical network circuit for individual bit processing, and are there executed. Similarly, during computer processing the commands for the computer are transferred directly to the computer and are there executed.
    Type: Grant
    Filed: July 13, 1982
    Date of Patent: May 14, 1985
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Ernst Schwefel
  • Patent number: 4462083
    Abstract: An improved method of interval interpolation, i.e., subdivision of a signal period, is disclosed. Generally, at least one scanning signal (S.sub.1, S.sub.2) generated by a scanning unit (G) scanning a scale (M) is converted into digital form and input to a computer (R) for the computation of interpolation values. In the case of a high subdivision factor, before the execution of the interpolation algorithm, the scanning signals input to the computer (R) are corrected for amplitude inequality, incorrect phase differential and the direct voltage component of the scanning signals (S.sub.1, S.sub.2). The correction values are automatically determined by direct voltage detectors (GT.sub.1, GT.sub.2), amplitude detectors (AT.sub.1, AT.sub.2) and a phase comparator (PV) during at least one pass of the measuring system (G, M) over its measuring interval. The correction values are stored in the computer (R) and are automatically utilized thereby in interpolation during measurement.
    Type: Grant
    Filed: June 24, 1981
    Date of Patent: July 24, 1984
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Ernst Schwefel
  • Patent number: 4412206
    Abstract: A digital electrical length or angle-measuring device connects digitalized scanning signals of at least one coarser revolution code group to first addressing inputs of one or more fixed value stores containing binary-stored calculated variants of the digitalized signals in form of tables, and the variants are alternately connected to outputs of the store in dependence upon the logical condition of the control signal which is derived from the respective higher resolution code groups and which is connected to a second addressing input of the store.
    Type: Grant
    Filed: September 18, 1980
    Date of Patent: October 25, 1983
    Assignee: Johannes Heidenhain GmbH
    Inventor: Ernst Schwefel
  • Patent number: 4330831
    Abstract: In a numerically controlled machine tool including a scale, a scanning unit, and a programmable controller a switch is provided to designate the tool correction to be applied to compensate for variations in tool dimensions. This switch has a first position, in which the controller is directed to lengthen the tool path length by an amount corresponding to the tool correction, a second position, in which the controller is directed to shorten the tool path length by an amount corresponding to the tool correction, and a third position, in which the controller is directed to apply no tool corrections to the tool path length.
    Type: Grant
    Filed: October 19, 1979
    Date of Patent: May 18, 1982
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Ernst Schwefel
  • Patent number: 4306220
    Abstract: An apparatus is disclosed for processing the output of an incremental measuring device of the type which provides a periodic analog output signal. The analog output signal is applied to a trigger circuit to produce a square wave signal which is applied as an input to an updown counter. This counter operates to count the number of complete cycles of the analog signal associated with the measurement. The analog signal is also applied to a circuit which acts to generate a coded intermediate value in response to the sign and amplitude of the analog signal. The counter value and the coded intermediate value are both applied as inputs to a computer which combines these two values to produce a composite reading in which the coded intermediate value supplies the high precision component of the reading and the counter value supplies the low precision component. In this way increased precision readings can be attained without increasing the maximum counting rate of the counter.
    Type: Grant
    Filed: December 20, 1978
    Date of Patent: December 15, 1981
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventors: Ernst Schwefel, Alfons Baumgartner
  • Patent number: 4229646
    Abstract: An improved counter for use with an incremental measuring device is disclosed which includes an up-down counter, a plurality of memory units, a computer, and means for designating any of the memory units. The computer is coupled to the counter and the memory units and is programmed to algebraically combine the value stored in the counter with the value stored in the designated memory unit to generate an output value for display. In the preferred embodiment, circuits are provided for setting the individual memory units to preselected values. The counter of this invention can be used to selectively display the measured position in any one of several measurement modes by designation of the appropriate memory unit.
    Type: Grant
    Filed: July 12, 1978
    Date of Patent: October 21, 1980
    Assignee: Johannes Heidenhain GmbH
    Inventors: Horst Burkhardt, Ernst Schwefel, Alfons Baumgartner, Anton Mayer, Michael Rauth
  • Patent number: 4225931
    Abstract: An interpolation process is described for use with an incremental position measuring device which produces a periodic analog output signal. The output signal is digitized and then applied as an input to a digital computer programmed to calculate the interpolation value of the signal. In the preferred embodiment the computer is also programmed to apply a number of corrections to the digitized signal prior to interpolation.
    Type: Grant
    Filed: June 15, 1978
    Date of Patent: September 30, 1980
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Ernst Schwefel