Patents by Inventor Ranjith Divigalpitiya

Ranjith Divigalpitiya 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).

  • Publication number: 20030129302
    Abstract: Provided is a dispenser for dispensing particles onto a surface comprising a hopper for receiving particles, wherein the hopper has an opening at its bottom, a screen having openings and located adjacent the opening of the hopper, wherein the screen openings are uniformly sized and spaced and are sufficiently large to let the largest particles pass through during dispensing yet sufficiently small to hold the particles back when the dispenser is not operating, and means, located outside of the hopper, for moving particles from the hopper through the screen, and onto the surface. Also provided is a method of making a web with embedded particles comprising the sequential steps of making the web receptive to the particles by heating, eliminating static charges present on the web, dispensing the particles onto the web, dispersing the particles to minimize particle clumping in the web, and embedding the dispensed particles in the web.
    Type: Application
    Filed: March 3, 2003
    Publication date: July 10, 2003
    Applicant: 3M Innovative Properties Company
    Inventors: David C. Chambers, Glen Connell, Ranjith Divigalpitiya, David E. Livingstone, Agatona D. Monteagudo, Susan C. Noe, Tejmeen K. Sandhu
  • Patent number: 6569494
    Abstract: A method for dispensing particles onto a surface. The steps of the process include holding the particles in a hopper having a dispensing opening covered by a screen which has uniformly sized openings that are sufficiently large to allow the largest particles to pass through, yet sufficiently small to hold the particles back when the dispenser is not operating; rotating, outside the hopper, a cylindrical brush covered with regularly spaced bristles and positioned such that the bristles protrude through openings in the screen and draw particles through the screen to dispense them onto the surface; and varying the dispensing rate of the particles by at least one of (a) varying the rotation speed of the brush, (b) adjusting the distance from the screen to the central longitudinal axis of the brush, (c) adjusting the screen opening size, (d) adjusting the brush-to-screen pressure, or (e) adjusting the tension of the screen. A method of making a web with embedded particles.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: May 27, 2003
    Assignee: 3M Innovative Properties Company
    Inventors: David C. Chambers, Glen Connell, Ranjith Divigalpitiya, David E. Livingstone, Agatona D. Monteagudo, Susan C. Noe, Tejmeen K. Sandhu
  • Patent number: 6511701
    Abstract: A method of coating a polymer substrate with a dry composition comprising particles is provided. The particles have a Mohs hardness between 1 and 2.5 and preferably a largest dimension of less than 100 microns. The particles are buffed on the substrate with an applicator which moves in a manner parallel to the surface of the substrate.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: January 28, 2003
    Assignee: 3M Innovative Properties Company
    Inventors: Ranjith Divigalpitiya, Gabriella Miholics, David C. Chambers
  • Publication number: 20020119255
    Abstract: The invention is an apparatus for dispensing particles onto a surface. The apparatus includes a hopper for receiving particles. The hopper includes a hopper opening. The screen is disposed over the hopper opening so as to cover the opening. A brush is disposed approximate to the screen such that bristles on the brush contact the screen.
    Type: Application
    Filed: November 9, 2001
    Publication date: August 29, 2002
    Inventors: Ranjith Divigalpitiya, David E. Livingstone
  • Patent number: 5637882
    Abstract: A detector plate for use in a radiation imaging system includes a first conductive layer, a dielectric layer, a photoconductive layer and a second conductive layer, arranged as a stack in that order. The first conductive layer and the dielectric layer are substantially transparent to radiation energy so as to allow the energy to pass therethrough to be received by the photoconductive layer. The first conductive layer has a periphery defined by a first edge and the dielectric layer has a periphery defined by a second edge, wherein the first edge is offset inward of the second edge defining a margin between the first and second edges. In use, this margin helps inhibit electrical arcing from the first conductive layer to the second conductive layer when a high voltage is applied between these two layers.
    Type: Grant
    Filed: December 1, 1995
    Date of Patent: June 10, 1997
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Ranjith Divigalpitiya, Bimsara W. Disanayaka, William B. Robbins, Earl L. Cook, Keith K. McLaughlin
  • Patent number: 4996108
    Abstract: Compositions of the formula MX.sub.2 :Y, wherein MX.sub.2 is a layer type transition metal dichalcogenide, M is a metal selected from the group consisting of niobium, tantalum, molybdenum and tungsten, X is a chalcogen selected from the group consisting of sulfur and selenium and Y is a material located between layers of MX.sub.2. The compositions may be prepared by the steps of first forming a suspension of the MX.sub.2 in a body of water. A liquid which is immiscible with water is added to the suspension. The suspension and immiscible liquid are agitated together to form a temporary emulsion. The emulsion is allowed to rest until the water and the liquid separate with an interface therebetween. A sheet-like composition of MX.sub.2 :Y forms at the interface. Preferably, the MX.sub.2 is in exfoliated, singular molecular thickness layers suspended in the water.
    Type: Grant
    Filed: January 17, 1989
    Date of Patent: February 26, 1991
    Assignee: Simon Fraser University
    Inventors: W. M. Ranjith Divigalpitiya, Robert F. Frindt, S. Roy Morrison