Patents by Inventor Dipak R. Biswas

Dipak R. Biswas 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: 11686504
    Abstract: A novel method is described for water heating using stored solar heat. Solar heat is stored in an insulated tank by using scrap and inexpensive heat absorbing or heat storing materials. Stored solar heat can then be used to heat water in a storage tank by extracting the solar heat using an antifreeze liquid which in turn heat cold water in the water tank. Water temperature in the storage tank is controlled by a thermostat. When the water temperature drops below the set point on the thermostat, a circulating pump turns on and pump the cold water until it reaches the desired set temperature. Once it reaches the set point in the thermostat, the water circulation pump turns off.
    Type: Grant
    Filed: July 29, 2020
    Date of Patent: June 27, 2023
    Inventor: Dipak R. Biswas
  • Publication number: 20220034551
    Abstract: A novel method is described for water heating using stored solar heat. Solar heat is stored in an insulated tank by using scrap and inexpensive heat absorbing or heat storing materials. Stored solar heat can then be used to heat water in a storage tank by extracting the solar heat using an antifreeze liquid which in turn heat cold water in the water tank. Water temperature in the storage tank is controlled by a thermostat. When the water temperature drops below the set point on the thermostat, a circulating pump turns on and pump the cold water until it reaches the desired set temperature. Once it reaches the set point in the thermostat, the water circulation pump turns off.
    Type: Application
    Filed: July 29, 2020
    Publication date: February 3, 2022
    Inventor: Dipak R. Biswas
  • Publication number: 20220034521
    Abstract: A novel method is described for room heating using stored solar heat. Solar heat is stored in an insulated tank by using scrap and inexpensive heat absorbing or heat storing materials. Stored heat can then be extracted by air circulation for room heating. The temperature of the room air is controlled by a thermostat. When the room temperature drops below the set point on the thermostat, a circulating air pump turns on and extract the solar heat until the room temperature air reaches the desired set temperature. Once room temperature reaches the set point in the thermostat, the air circulation pump turns off.
    Type: Application
    Filed: July 29, 2020
    Publication date: February 3, 2022
    Inventor: Dipak R. Biswas
  • Publication number: 20110093131
    Abstract: The house hold appliances, such as refrigerators and freezers are usually turned on all day (24/7) long. They consume electricity throughout day and night. The flow of electricity through these appliances can be controlled for a finite period of time so that the food or other stored products are not going to be spoiled. The consumption of electricity can be reduced significantly by using a programmable timer or time switch. The programmable timer or time switch can be plugged into the wall and the power chord of the refrigerator or freezer can be plugged into the timer. The timer or time switch can be built-in to the appliances. The refrigerator or freezer with a built-in timer will control the flow of electricity by deliberately shutting of the power for a fixed period of time.
    Type: Application
    Filed: October 19, 2009
    Publication date: April 21, 2011
    Inventor: Dipak R. Biswas
  • Patent number: 5337381
    Abstract: A fiber optic, cylindrical, light diffuser for medical use includes an unclad distal fiber end where the exposed core end has a conical shape. The core end is enclosed by a sleeve which contacts the clad portion of the fiber only and defines a closed chamber with the distal end of the fiber. The chamber is filled with light diffusing material. The diffuser exhibits highly uniform output light distribution and is capable of carrying relatively high power densities safely.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: August 9, 1994
    Assignee: Fiberguide Industries
    Inventors: Dipak R. Biswas, Anpei Pan
  • Patent number: 4838918
    Abstract: In the manufacture of optical fibers, at least a portion of a preform of optical glass is heated into a molten state and drawn to create an optical fiber of the desired diameter. To cool the fiber during the drawing process and prior to coating thereof, the invention contemplates providing a cooling device with a laminar flow of inert gas therein to surround and cool the fiber.
    Type: Grant
    Filed: December 1, 1987
    Date of Patent: June 13, 1989
    Assignee: Alcatel NA
    Inventors: A. Dahlgren Vaughan, Dipak R. Biswas
  • Patent number: 4790625
    Abstract: An optical fiber which has just been drawn from an optical preform is provided with two external hermetic coatings. The primary coating is a metallic or dielectric coating provided by, for example, using a heterogeneous nucleation thermochemical deposition (HNTD) technique. This technique involves passing the fiber through a reaction zone which contains a gaseous medium that includes a reactant which decomposes, or a mixture of reactants which chemically react, at a predetermined temperature, to form the material of the coating. Such predetermined temperature is available from the heat of the fiber forming process which is retained at the fiber surface by means of a shielding element so that additional heating means is not required. The second coating may be deposited, by for example, using an HNTD or a chemical vapor deposition process. The resulting fiber may then be provided with an additional polymer coating layer.
    Type: Grant
    Filed: August 20, 1987
    Date of Patent: December 13, 1988
    Assignee: Alcatel USA, Corp.
    Inventors: Dipak R. Biswas, Satyabrata Raychaudhuri
  • Patent number: 4750806
    Abstract: Solid fibers or capillaries are coated with a metal, alloy or dielectric capable of withstanding temperatures in excess of 300.degree. C. and preferably 500.degree. C. The coating is deposited by a heterogeneous nucleation thermochemical deposition process occurring on the surface of the fiber.
    Type: Grant
    Filed: June 17, 1985
    Date of Patent: June 14, 1988
    Assignee: Alcatel USA Corporation
    Inventor: Dipak R. Biswas
  • Patent number: 4592932
    Abstract: An optical fiber which has just been drawn from an optical preform is provided with two external hermetic coatings. The primary coating is a metallic coating provided by, for example, using a heterogeneous nucleation thermochemical deposition technique. This technique involves passing the fiber through a reaction zone which contains a gaseous medium that includes a reactant which decomposes, or a mixture of reactants which chemically react, at a predetermined temperature to form the material of the coating. The second coating is provided by immersing the fiber in a deposition bath containing a liquid medium which includes at least one reactant capable of deposition onto the primary coating to form a secondary coating. The deposition process may be achieved by applying a current through the medium at a predetermined temperature or by including reactants in the medium which will deposit at predetermined temperatures without applying a current.
    Type: Grant
    Filed: June 26, 1984
    Date of Patent: June 3, 1986
    Assignee: ITT Corporation
    Inventors: Dipak R. Biswas, Satyabrata Raychaudhuri
  • Patent number: 4575463
    Abstract: An optical fiber which has just been drawn from an optical preform is provided with two external hermetic coatings. The primary coating is a metallic or dielectric coating provided by, for example, using a heterogeneous nucleation thermochemical deposition (HNTD) technique. This technique involves passing the fiber through a reaction zone which contains a gaseous medium that includes a reactant which decomposes, or a mixture of reactants which chemically react, at a predetermined temperature, to form the material of the coating. Such predetermined temperature is available from the heat of the fiber forming process which is retained at the fiber surface by means of a shielding element so that additional heating means is not required. The second coating may be deposited, by for example, using an HNTD or a chemical vapor deposition process. The resulting fiber may then be provided with an additional polymer coating layer.
    Type: Grant
    Filed: August 24, 1984
    Date of Patent: March 11, 1986
    Assignee: ITT Corporation
    Inventors: Dipak R. Biswas, Satyabrata Raychaudhuri
  • Patent number: 4518628
    Abstract: An optical fiber which has just been drawn from an optical preform is provided with an external hermetic coating by using a heterogeneous nucleation thermochemical deposition technique. This technique involves passing the fiber through a reaction zone which contains a gaseous medium that includes a reactant which decomposes, or a mixture of reactants which chemically react, at a predetermined temperature to form the material of the coating. Only the fiber but not the gaseous medium surrounding the same is heated to the predetermined temperature, especially by directing radiation onto the exposed circumferential surface of the fiber, so that the decomposition or the chemical reaction takes place directly on the exposed surface of the fiber rather than in the gaseous medium, accompanied by simultaneous deposition of the coating material on the exposed surface of the fiber. The resulting fiber with hermetic coating can then be provided with an additional polymer coating layer.
    Type: Grant
    Filed: February 17, 1984
    Date of Patent: May 21, 1985
    Assignee: International Telephone and Telegraph Corporation
    Inventors: Dipak R. Biswas, Dilip K. Nath
  • Patent number: 4485122
    Abstract: A metallic material coating is applied to the external surface of a freshly drawn optical fiber while such surface is still pristine by passing the optical fiber through a body of liquid metal-organic material which forms a layer on the fiber, and by subsequently removing all non-metallic components from the layer of metal-organic material by volatilizing the same. The optical fiber with the layer metal-organic material is passed through a baking oven in which at least the layer is heated to a baking temperature at which organic materials present in the metal-organic material are volatilized and the remainder is baked to the fiber. Then, at least the layer is fired in a firing chamber at a higher temperature at which the metal-organic material is decomposed into its volatile non-metallic and non-volatile metallic components, the latter remaining in the layer and the former becoming volatile and leaving the layer.
    Type: Grant
    Filed: March 23, 1983
    Date of Patent: November 27, 1984
    Assignee: International Telephone and Telegraph Corporation
    Inventors: Joseph C. Williams, Jeff P. Garmon, Dipak R. Biswas, Dilip K. Nath
  • Patent number: 4443239
    Abstract: A tubular formation of particulate optical material is formed by a layer slurry deposition process which involves spraying layer after layer of slurry containing particles of the optical material onto a rotating rod-shaped bait. The composition of the slurry and particularly the index of refraction of the optical material may be varied from one layer to another or from one group of layers to another to obtain a graded or stepped refraction index profile in the formation, in an optical preform formed therefrom, and ultimately in the fiber drawn from the optical preform. The particles of the slurry are suspended in a liquid vehicle which evaporates in the spray stream or shortly after deposition, and are coated with an organic binder which holds them together in the layer and in the formation, so that the formation is self-supporting. Then, the organic binder is removed and the formation is sintered, followed by a collapse of the sintered tubular formation into the optical preform in the form of a solid rod.
    Type: Grant
    Filed: May 20, 1982
    Date of Patent: April 17, 1984
    Assignee: International Telephone and Telegraph Corporation
    Inventors: Dipak R. Biswas, Dilip K. Nath