Patents by Inventor Wilfried Lehmann

Wilfried Lehmann 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: 5549450
    Abstract: Centrifugal pump of the sectional-casing design, in which the casing sections (8, 9) each have a cylindrical casing shell and inner-wall parts (12-15) connected thereto in one piece. The casing shell of at least one casing section (8, 9) is composed of an outer, continuous shell part (24, 25) and of at least two separate inner shell parts (19-22) with respective associated inner-wall parts (12-15). The outer and the inner shell parts are expediently connected firmly to one another, especially by shrink bonding.
    Type: Grant
    Filed: March 16, 1995
    Date of Patent: August 27, 1996
    Assignee: Sihi GmbH & Co KG
    Inventors: Ralf Mann, Wilfried Lehmann, Hermann Muller
  • Patent number: 4979875
    Abstract: Centrifugal pump for the delivery of hot media, in particular of hot water with at least one shaft passage through the pump housing (1,2) to the outside, which passage is provided with a mechanical seal (5). The sealing space is separated from the pump housing by a spacer zone (8) with close shaft play. For the avoidance of sealing disturbances by accumulated gas, the sealing space contains first means (12, 20, 21) for the generation of a liquid circulation in the sealing space with intensive impingement of the sliding surface area of the mechanical seal, second means (12, 18,21) for the stabilization of the liquid circulation away from the mechanical seal and thirdly a large-volume, flow-stabilized, ventable receiving space for separated gas. The gas fractions are thereby reliably isolated from the mechanical seal, separated from the liquid circulation and accumulate in the upper region of the sealing space, so that they are extracted from the liquid circulation and can be drawn off.
    Type: Grant
    Filed: April 14, 1989
    Date of Patent: December 25, 1990
    Assignee: Sihi GmbH & Co. KG
    Inventors: Hermann Muller, Wilfried Lehmann, Ralf Mann
  • Patent number: 4390317
    Abstract: The invention relates to a centrifugal pump having a first centrifugal pump stage (2), which is located on the suction side and is not self-priming, and having a pump inlet nozzle (6), which is located axially at the level of the horizontal shaft (1), and having at least one centrifugal pump stage (3). which is located downstream and which, operating with the aid of auxiliary liquid, is self-priming. According to the invention, the self-priming capability and reliability of the pump, in particular for conveying media in the vicinity of their boiling point, are improved by arranging a liquid reservoir (13), of sufficient size, between two pump stages, the connection from this reservoir to the preceding centrifugal pump stage being located in the geodetically upper portion of the reservoir, and a seal (16) for closing the shaft clearance being located between the liquid reservoir (13) and the preceding centrifugal pump stage.
    Type: Grant
    Filed: July 31, 1981
    Date of Patent: June 28, 1983
    Assignee: Sihi GmbH & Co. KG
    Inventors: Wilfried Lehmann, Peter Fandrey
  • Patent number: 4230438
    Abstract: A rotary pump assembly including a pump having a pump housing, a pump shaft disposed within the pump housing, a runner mounted concentrically on the pump shaft, a motor having a motor housing, and an intermediate housing interconnected between the pump- and motor-housings. The pump shaft has an end facing the motor, and the pump shaft end is formed as a hollow shaft fittingly mounted on the motor shaft. A bearing support is disposed in the intermediate housing for supporting the hollow pump shaft end, and is formed as an axial bearing with substantially no radial bearing capacity.
    Type: Grant
    Filed: May 2, 1979
    Date of Patent: October 28, 1980
    Assignee: Sihi GmbH & Co. KG
    Inventors: Wilfried Lehmann, Hermann Muller, Bodo Baranek
  • Patent number: 4149574
    Abstract: Apparatus for selectively charging and evacuating a separate liquid system such as an engine cooling system, refrigeration system or the like and having a liquid storage tank, a single fluid pump and valve means for selectively connecting both the pump inlet and pump outlet for either pumping liquid from the storage tank via a connector conduit to the separate system or from the separate system via the connector conduit to the storage tank.
    Type: Grant
    Filed: October 18, 1977
    Date of Patent: April 17, 1979
    Assignee: Sihi GmbH & Co.
    Inventors: Wilfried Lehmann, Erwin Zimmermann