Patents by Inventor Richard Frank Mitchell

Richard Frank Mitchell 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).

  • Liquid collection
    Patent number: 6203150
    Abstract: A liquid collection apparatus comprises a liquid collecting device and liquid conduit for transferring liquid from the liquid collection device. Porous liquid absorption device is positioned between the liquid collection device and the liquid conduit. Pump device pumps liquid from the liquid conduit, the pump device generating a pressure in the conduit that is sufficient to draw liquid through the liquid collection device but is insufficient to draw a gas/liquid surface through the liquid absorption device.
    Type: Grant
    Filed: April 8, 1999
    Date of Patent: March 20, 2001
    Assignee: Domino Printing Sciences Plc
    Inventors: Jerzy Marcin Zaba, William Anthony Denne, Richard Frank Mitchell
  • Acoustic surface wave devices
    Patent number: 3983515
    Abstract: An acoustic surface wave device comprising a monocrystalline body of piezoelectric material having a launching and receiving transducer applied to a planar ASW propagation surface. The piezoelectric material and the orientation of the propagation surface and the axial propagation direction relative to the crystal axes are selected to provide zero piezoelectric coupling between the transducers and a longitudinal axial bulk wave and that one of the two shear axial bulk waves that has substantially no component of particle motion perpendicular to said propagation surface. A method of manufacturing the aforesaid ASW device is also disclosed.
    Type: Grant
    Filed: October 10, 1974
    Date of Patent: September 28, 1976
    Assignee: U.S. Philips Corporation
    Inventors: Richard Frank Mitchell, Eileen Read, Richard Stevens
  • Acoustic surface-wave devices
    Patent number: 3968461
    Abstract: A surface wave TV I.F. filter has a transducer with two passbands. Each is unsymmetrical with respect to itself and a mirror image of the other. A second transducer suppresses one of the passbands.
    Type: Grant
    Filed: September 3, 1974
    Date of Patent: July 6, 1976
    Assignee: U.S. Philips Corporation
    Inventors: Richard Frank Mitchell, David William Parker, Bernard David Rapson
  • Acoustic surface-wave devices using mono crystalline bismuth silicon oxide substrate
    Patent number: 3956647
    Abstract: An acoustic surface wave filter comprising a monocrystalline wafer of bismuth silicon oxide having a special orientation of the ASW propagation surface and the interdigital transducers relative to the crystal plane whereby pick-up of undesired bulk waves is reduced.
    Type: Grant
    Filed: October 15, 1974
    Date of Patent: May 11, 1976
    Assignee: U.S. Philips Corporation
    Inventors: Richard Frank Mitchell, Eileen Read, Richard Stevens
  • Acoustic surface wave devices
    Patent number: 3955159
    Abstract: An acoustic surface wave device comprises a launching transducer and a receiving transducer coupled to one surface of a piezoelectric substrate and including means for suppressing spurious signals developed in the receiving transducer due to acoustic surface waves reflected from the ends of the substrate. In one embodiment the electrodes of both transducers are staggered a quarter wavelength at the mid point of their apertures so that waves received direct from the launching transducer arrive in phase at the receiving transducer whereas end reflected waves arrive in antiphase over the two halves of the receiving transducer aperture.
    Type: Grant
    Filed: September 13, 1974
    Date of Patent: May 4, 1976
    Assignee: U.S. Philips Corporation
    Inventors: Richard Frank Mitchell, Richard Stevens