Patents by Inventor Andrew S. Sweetana

Andrew S. Sweetana 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: 5264169
    Abstract: A method of manufacturing a varistor utilizes preselected amounts of ZnO which are combined with specified amounts of additives including B, Na, Bi.sub.2 O.sub.3 and BaO to form a variety of compositions. Each composition is pressed into a disc. The disc is then sintered at a first selected temperature. Afterwards, the disc is annealed at a second selected temperature. The specific compositions disclosed render a varistor with improved high temperature performance when the annealing step is followed with a low temperature tempering cycle at approximately 250.degree. C.
    Type: Grant
    Filed: April 23, 1991
    Date of Patent: November 23, 1993
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Kenneth C. Radford, Robert G. Johnson, Andrew S. Sweetana, Jr.
  • Patent number: 5142264
    Abstract: A method for producing varistors having high energy absorption. The high energy absorption is achieved by combining predetermined quantities of Bi.sub.2 O.sub.3, BaO, SiO.sub.2 and Sb.sub.2 O.sub.3 with ZnO to produce a mixture which is sintered to produce a varistor disc having high energy absorption.
    Type: Grant
    Filed: December 15, 1989
    Date of Patent: August 25, 1992
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Kenneth C. Radford, Robert G. Johnson, Andrew S. Sweetana, Jr.
  • Patent number: 5053739
    Abstract: A varistor utilizing a disc of mainly ZnO in combination with preselected combinations of Bi.sub.2 O.sub.3, Sb.sub.2 O.sub.3, SiO.sub.2, MgO and CaO.
    Type: Grant
    Filed: December 15, 1989
    Date of Patent: October 1, 1991
    Assignee: Electric Power Research Institute
    Inventors: Kenneth C. Radford, Robert G. Johnson, Andrew S. Sweetana, Jr.
  • Patent number: 5037594
    Abstract: A method for making a varistor disc with increased high temperature stability. The method includes the steps of formulating a mixture for the varistor disc, compacting the mixture to form a disc, sintering the disc at a first preselected temperature and cooling the disc at a predetermined linear rate. The predetermined linear rate and preselected temperature are selected to reduce nonequilibrium conditions which become "frozen-in" as said disc is cooled.
    Type: Grant
    Filed: December 15, 1989
    Date of Patent: August 6, 1991
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Kenneth C. Radford, Robert G. Johnson, Andrew S. Sweetana, Jr.
  • Patent number: 4945333
    Abstract: A fuse assembly for an electrical cutout is provided with capability for rapid arc extinction by a capsule of pressurized insulating gas being located within a fuse tube above the fusible element so that when the fusible element melts and an arc is produced, gas is released from the gas cylinder that quenches and cools the arc and also assists a spring loaded flipper mechanism in expelling a lower conductor from the fuse tube.
    Type: Grant
    Filed: February 13, 1989
    Date of Patent: July 31, 1990
    Assignee: Asea Brown Boveri Inc.
    Inventors: Nicholas J. Stroud, Andrew S. Sweetana, Jr., Frederick J. Brown, Thomas P. Basa
  • Patent number: 4663692
    Abstract: A disconnector for lightning arresters is provided that incorporates a gas cylinder with a dielectric gas such as carbon dioxide which will be released upon an excess current and result in the extinguishing of the arc in the disconnector spark gap prior to danger of shattering of the arrester housing.
    Type: Grant
    Filed: June 27, 1985
    Date of Patent: May 5, 1987
    Assignee: Westinghouse Electric Corp.
    Inventors: Charles H. Carothers, Andrew S. Sweetana
  • Patent number: 4577148
    Abstract: A metal oxide type surge arrester is provided with a plurality of arrester blocks in series within a housing having, in addition to line and ground terminals at the extremities, a bushing providing a tap voltage terminal intermediate the series stack such as between the bottom two arrester blocks. The provision of the voltage tap and a shunt resistance in series with the ground terminal permits respectively detecting the voltage and the current of the arrester so that they can be compared and their phase relation observed to determine if the arrester blocks are maintaining a capacitive characteristic or have become resistive. In addition, several other methods of use of such an arrester for monitoring line voltage, energy absorption, fault current and the like are disclosed.
    Type: Grant
    Filed: December 17, 1982
    Date of Patent: March 18, 1986
    Assignee: Westinghouse Electric Corp.
    Inventor: Andrew S. Sweetana
  • Patent number: 4549981
    Abstract: A voltage limiting composition, actually a nonlinear resistor, especially suitable for use in a gapless surge arrester is disclosed herein. This composition includes a predetermined amount of zinc oxide as its primary ingredient and one or more specifically selected additives. All of these constituents are combined and sintered so that the composition displays a nonlinear exponent .alpha. at least equal to about 35 over the current range of 1 ma to 5000 amps and such that its energy absorption capability is at least equal to about 50 joules/cm.sup.3.
    Type: Grant
    Filed: September 17, 1982
    Date of Patent: October 29, 1985
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Tapan K. Gupta, William G. Carlson, Joseph C. Osterhout, Gerald B. Boyette, Andrew S. Sweetana, Jr.
  • Patent number: 4477792
    Abstract: The present invention discloses a modular reactor that increases the inductance per axial length by winding a conductor circumferentially about a central axis in a manner which results in radially extending columns which are sequentially wound in alternating radial order. The modules are constructed to allow them to be combined in either radial or axial juxtaposition and electrically connected either in series or in parallel.
    Type: Grant
    Filed: January 29, 1982
    Date of Patent: October 16, 1984
    Assignee: Westinghouse Electric Corp.
    Inventors: Thomas H. Putman, Andrew S. Sweetana, Jr., Frederick J. Brown
  • Patent number: 4460497
    Abstract: A sintered nonlinear resistor body, useful in gapless lightning arresters comprises a major amount of ZnO and additional metal oxides including at least Al.sub.2 O.sub.3 and an amount of selected alkali metal oxide of from about 0.003 mole % to about 0.2 mole %.
    Type: Grant
    Filed: February 18, 1983
    Date of Patent: July 17, 1984
    Assignee: Westinghouse Electric Corp.
    Inventors: Tapan K. Gupta, William G. Carlson, Andrew S. Sweetana
  • Patent number: 4452729
    Abstract: A sintered nonlinear resistor body, useful in gapless lightning arresters comprises a major amount of ZnO and additional metal oxides including at least Al.sub.2 O.sub.3 and an amount of boron oxide of from about 0.005 mole % to about 0.25 mole %.
    Type: Grant
    Filed: November 3, 1982
    Date of Patent: June 5, 1984
    Assignee: Westinghouse Electric Corp.
    Inventors: William G. Carlson, Tapan K. Gupta, Andrew S. Sweetana, Jr.
  • Patent number: 4452728
    Abstract: A sintered nonlinear resistor body, useful in gapless lightning arresters comprises a major amount of ZnO and additional metal oxides including at least Al.sub.2 O.sub.3 and an amount of boron oxide of from about 0.005 mole % to about 0.6 mole %, in combination with a total amount of at least one selected alkali metal oxide of from about 0.005 mole % to about 0.3 mole %.
    Type: Grant
    Filed: February 18, 1983
    Date of Patent: June 5, 1984
    Assignee: Westinghouse Electric Corp.
    Inventors: William G. Carlson, Tapan K. Gupta, Andrew S. Sweetana, Jr.
  • Patent number: 4223366
    Abstract: A gapless surge arrester is disclosed herein and includes a porcelain outer casing and a stack of zinc oxide discs located within the casing for passing surge currents therethrough. Silicon dioxide, preferably sand, is provided between this stack in the casing for transferring heat from the discs to the porcelain outer casing as a result of the surge current and for absorbing fault energy where necessary by changing states.
    Type: Grant
    Filed: November 15, 1978
    Date of Patent: September 16, 1980
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Andrew S. Sweetana, Jr., Tapan K. Gupta, Richard E. Kothmann, Joseph C. Osterhout
  • Patent number: T966010
    Abstract: a compensating reactor in a coupling capacitor potential device including a magnetic core with an inductive winding, the reactor providing inductive reactance cancelling capacitive reactance of the device, and a voltage limiting device connected across the compensating reactor which is a ceramic oxide non linear resistor. The reactor core can be a magnetic steel whose normal saturation level substantially exceeds the voltage at which the voltage limiter changes resistance.
    Type: Grant
    Filed: April 7, 1977
    Date of Patent: January 3, 1978
    Assignee: Westinghouse Electric Corporation
    Inventors: Andrew S. Sweetana, Jr., Gerald B. Boyette, Frederick J. Brown
  • Patent number: T967008
    Abstract: a coupling capacitor protection device with a voltage limiter connected across the tap capacitor feeding the induction transformer primary winding. The suppressor is a ceramic oxide nonlinear resistor changing from high to low resistance, thereby limiting the tap voltage to less than that at which the induction transformer core saturates in order to minimize ferroresonance in the circuit. Also, the limiter gives voltage protection to the tap capacitor circuit.
    Type: Grant
    Filed: April 7, 1977
    Date of Patent: February 7, 1978
    Assignee: Westinghouse Electric Corporation
    Inventors: Andrew S. Sweetana, Jr., Frederick J. Brown, Gerald B. Boyette