Patents by Inventor Johann B. Pfeffer

Johann B. Pfeffer 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).

  • Drainage device for particulate material
    Patent number: 4110214
    Abstract: A drainage device for particulate material in liquid suspension is in the form of a rotating wheel having circumferentially spaced foraminous buckets scooping out liquid and suspended particulate material from a vessel. Rotation of the wheel about its axis takes place in arcuate steps by the operation of a pair of axially spaced plunger and cylinder assemblies engaging alternately in cyclic fashion with shoulders circumferentially spaced about the wheel axis.
    Type: Grant
    Filed: November 29, 1976
    Date of Patent: August 29, 1978
    Assignee: S.A. Block & Concrete (Proprietary) Limited
    Inventor: Johann B. Pfeffer