Patents by Inventor Johannes Liefke

Johannes Liefke 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: 4900252
    Abstract: A recognition system is provided for tools, such as drill bits and milling bits, which are insertable into dental treatment instruments, each of the tools having an optimum speed at which the tool must be rotated for effective treatment. In the recognition system, each tool is provided with a code corresponding to the speed or speed graduation necessary to effectively use the tool. The system also includes a reader which reads the code on each tool, and generates identifying signals in accordance with the code, which are supplied to an evaluation logic. The logic converts the signal from the reader into control signals for the drive motor used to operate the tool, as well as indicator signals for visually displaying information relating to the tool currently in use.
    Type: Grant
    Filed: July 11, 1988
    Date of Patent: February 13, 1990
    Assignee: Siemens Aktiengesellschaft
    Inventors: Johannes Liefke, Bernd Nickel, Josef Pabst, Otto Fleer
  • Patent number: 4308011
    Abstract: An improved apparatus for storing dental handpieces which includes a support device for each of the handpieces and a switching device for creating a signal when a handpiece is disposed in the supporting devices without contacting the handpiece. In one embodiment, the sensing device utilizes a light barrier which is broken by placing the handpiece in the supporting device and in another embodiment the sensing device utilizes a coil and resonant circuit whose output is changed by the presence of the handpiece.
    Type: Grant
    Filed: May 17, 1979
    Date of Patent: December 29, 1981
    Assignee: Siemens Aktiengesellschaft
    Inventor: Johannes Liefke