Patents by Inventor Michel Ferre

Michel Ferre 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).

  • Dynamic photoelasticimeter with rotating birefringent element
    Patent number: 4179217
    Abstract: This invention relates to a dynamic photoelasticimeter with a rotating birefringent element. It comprises a laser, a birefringent plate rotatable at a constant speed, a model to be studied, a circular analyzer and a photodetector supplying signals at its output having frequency components of 2.omega. and 4.omega.. The ratio of the amplitudes of these signals supplies an indication of the phase shift .phi. (t) contributed by the model, and the phase of the signal of the frequency 4.omega. contributes information as to the orientation .theta. of the axes of the model at the point in question.The present invention provides a particularly simple and accurate dynamic photoelasticimeter.
    Type: Grant
    Filed: February 14, 1978
    Date of Patent: December 18, 1979
    Assignee: Etat Francais as represented by the Delegue General pour l'armement
    Inventors: Andre J. Robert, Jean C. Filippini, Michel Ferre