Patents by Inventor Paul J. Lefebvre

Paul J. Lefebvre 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: 5513526
    Abstract: The present invention relates to measuring device for measuring a component f a force acting on a test body, such as a hydrofoil, positioned within a testing apparatus. The measuring device has a test body formed by a foil shaped center section and two adjacent end sections. Each end section is joined to the center section by a flexure member having sufficient stiffness so that there is negligible relative motion between the center section and the end sections as a fluid medium flows past the center section. At least one strain gauge is mounted to at least one flexure member to measure the forces acting on the center section. A method for measuring the load on a test body is also described.
    Type: Grant
    Filed: July 20, 1994
    Date of Patent: May 7, 1996
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Paul J. Lefebvre, William P. Barker
  • Patent number: 5307688
    Abstract: An electromagnetic flowmeter and a method for measurement of the rate of flow of a fluid under unsteady conditions are described. It uses fluid steady-state flowmeter technology and a new algorithm to measure transient rate of flow of a fluid such as water. The algorithm teaches (a) measuring the e.m.f. generated due to the rate of flow of the fluid under test moving through a tube placed in an area with uniform magnetic flux, and (b) comparing it to a simultaneously generated reference signal which is measure of the magnetic flux density generated when an electromagnetic flowmeter is energized due to the fluid flow rate at the instant of taking the flow rate data of the fluid.
    Type: Grant
    Filed: December 24, 1990
    Date of Patent: May 3, 1994
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Paul J. Lefebvre
  • Patent number: 5231883
    Abstract: An apparatus for defining the free surface of a moving column of a fluid in vertical pipe to enhance the accuracy of measurements of transient rate of flow of the fluid using electromagnetic flowmeter is described. It provides a neutrally buoyant plug which stays in contact with the free surface of the column of the fluid at all times and thus defines the free surface of the fluid moving in the vertical pipe accurately and reduces the oscillations of the free surface of the fluid.
    Type: Grant
    Filed: December 24, 1990
    Date of Patent: August 3, 1993
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Paul J. Lefebvre, William W. Durgin
  • Patent number: 5205162
    Abstract: A facility for permitting launch performance tests to be conducted on an erwater vehicle, such as a torpedo, includes a housing having an opening therethrough defining a tubular chamber for receiving a vehicle therein. A piston is also positioned within the tubular chamber. A link disposed between the piston and the vehicle has a pair of opposing end portions connected with the piston and the vehicle, respectively. A channel is positioned adjacent to the housing and has water flowing therein at a predetermined velocity. The water within the channel communicates with the tubular chamber to allow water flowing within the channel to enter the tubular chamber and surround the vehicle with the vehicle at its rest position. A drive device is operable to move the piston through the tubular chamber a preselected distance sufficient to move the vehicle and the water surrounding the vehicle out of the tubular chamber and into the channel.
    Type: Grant
    Filed: October 5, 1992
    Date of Patent: April 27, 1993
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Paul J. Lefebvre, John A. Schwemin
  • Patent number: 5078009
    Abstract: A system is described for testing a pump or a turbine impeller under transient operating conditions in a fluid flow. The system provides simultaneously, as a function of time, user defined impeller speeds, fluid flow rate and rise in fluid pressure so as to simulate real conditions. This information can be used to analyze the performance of existing impellers or for designating new impellers.
    Type: Grant
    Filed: December 24, 1990
    Date of Patent: January 7, 1992
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Paul J. Lefebvre
  • Patent number: 4380935
    Abstract: A vortex-sensing fluid flowmeter has a freely rotatable vortex-shedding body suspended in a section of conduit through which a fluid stream passes, the body being oriented generally transverse to the direction of fluid flow. The body has an integrally formed upstream-facing portion adapted to shed a series of vortices within the fluid, which vortices alternately influence opposite lateral faces of the body, tending to produce a periodic rotation of the body about a firmly attached rotational shaft. The shaft is rotatably mounted to the conduit and passes at one end through the wall of the conduit to the exterior thereof. A sleeve-like tube surrounds the shaft and is fastened tightly at its bottom end to the shaft and at its top end to the conduit wall to provide a fluid-tight seal around the shaft. The tube is sufficiently flexible and pliable to exert negligible restraining force against the rotation of the shaft.
    Type: Grant
    Filed: February 20, 1981
    Date of Patent: April 26, 1983
    Assignee: The Foxboro Company
    Inventors: George E. Sgourakes, Paul J. Lefebvre
  • Patent number: H1326
    Abstract: A system is described for providing means by which the flow in a fluid such s water in a fluid flow loop can be accurately controlled to undergo user defined transients. Besides, the system allows for velocity variations over a wide range of velocities.
    Type: Grant
    Filed: December 24, 1990
    Date of Patent: July 5, 1994
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Paul J. Lefebvre