Patents Represented by Law Firm Duckworth, Allen, Dyer & Doppelt
  • Patent number: 4904961
    Abstract: This invention relates to a blocking oscillating converter for transferring energy from a source of power, such as a vehicle battery, to a storage means, such as an energy storage capacitor in a capacitor discharge ignition system. A novel control and feedback circuit incorporated in the blocking oscillator allows the drive level to the switching transistor to be controlled in response to the peak current in said transistor as well as the output voltage of the blocking oscillator. Furthermore the control circuit allows the blocking oscillator to be turned off during the short period of time after each spark discharge that is needed for turnoff of a switching device used to control that discharge.
    Type: Grant
    Filed: May 15, 1989
    Date of Patent: February 27, 1990
    Inventor: Floyd M. Minks
  • Patent number: 4880057
    Abstract: A process of removing carbonates from a well of a water collection and treatment system utilizes "aggressive" water obtained prior to the end of the water treatment process to remove carbonate deposits from the well. A preferred embodiment uses water which is the product of a reverse osmosis desalinization water treatment step and which is injected with carbon dioxide to form an aqueous carbonic acid solution for removal of the carbonate.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: November 14, 1989
    Inventor: Richard W. Derowitsch
  • Patent number: 4870770
    Abstract: A three-position firearm safety mechanism has bolt lock arm, user-operated lever and sear safety arm including inner eccentric end members interconnected by a trigger assembly pin, with the lower blade-like end of the lever slidably received within an outwardly facing channel on the sear safety arm and having a boss connected to an offset eccentric aperture in the lower arm, to permit the bolt lock arm to be temporarily disengaged from the bolt notch by depressing the lever against a spring bias while the safety is rotated to the firearm "safe" position.
    Type: Grant
    Filed: March 14, 1988
    Date of Patent: October 3, 1989
    Assignee: Ultra Light Arms, Inc.
    Inventors: Melvin D. Forbes, William F. Malone, Jr.
  • Patent number: 4868390
    Abstract: A pyroelectric sensor circuit arrangement for reducing noise and increasing sensitivity has a main current amplifier with a high feedback resistor connected to receive input from an electrode of a pyroelectric element, and includes a compensation amplifier in a unity gain amplifier configuration connected to a common power source with the main amplifier. The compensation amplifier is connected to discharge transients from the pyroelectric element when electrode voltage exceeds the positive voltage or goes below the negative voltage of the power source. A pair of anti-parallel diode or similar component is connected between the main amplifier input and the compensation amplifier output.
    Type: Grant
    Filed: February 16, 1988
    Date of Patent: September 19, 1989
    Assignee: ELTEC Instruments, Inc.
    Inventors: Hans J. Keller, Fredrick Villers
  • Patent number: 4860346
    Abstract: A telephone having a hook switch is coupled to tip and ring conductors for receiving loop current from a central office responsive to an off-hook condition at the hook switch. The electronic circuitry within the telephone for facilitating various functions is powered entirely from the loop current flowing from the central office during the off-hook condition; with loop current being maintained after termination of the off-hook condition in order to perform certain call functions.
    Type: Grant
    Filed: December 22, 1986
    Date of Patent: August 22, 1989
    Assignee: Protel, Inc.
    Inventor: Regis B. Mellon
  • Patent number: 4835944
    Abstract: An apparatus and method for nesting a carton bottom with an open-sided carton top includes a work surface having a first end and a discharge end, and feed stations along the work surface for feeding the carton bottom and top onto the work surface. A conveyor and dog arrangement engages the carton bottom near one feed station and moves the carton bottom in a first direction along the work surface toward the discharge end, with a pair of pivoted flaps along the direction of travel for centering and guiding the carton bottom into a nesting arrangement with the carton top as the carton bottom moves along the direction of travel.
    Type: Grant
    Filed: November 2, 1987
    Date of Patent: June 6, 1989
    Inventor: Robert M. Herrin
  • Patent number: 4832013
    Abstract: A portable floating apparatus for providing pressurized air to a submerged diver. The apparatus is comprised of the combination of a gasoline engine and an air compressor, said combination being housed in a buoyant container similar to a suitcase. The gasoline engine is preferably a two-stroke engine which drives the air compressor. The top of the container has large outlets for the intake of fresh air for compression, engine cooling and the exit of exhaust gases. These outlets have cowlings extending therefrom to reduce flooding by water from spraying or waves in rough seas. A small outlet on the side of the container with a coupling allows a flexible hose to supply air to a submerged diver. An optional fan may be inserted in the duct of one cowling to provide additional ventilation and cooling. The air supply hose, cowlings and other exterior components can be stored in the container when not in use.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: May 23, 1989
    Inventor: Jeffrey L. Hartdorn
  • Patent number: 4829971
    Abstract: This invention relates to a blocking oscillating converter for transferring energy from a source of power, such as a vehicle battery, to a storage means, such as an energy storage capacitor in a capacitor discharge ignition system. A novel control and feedback circuit incorporated in the blocking oscillator allows the drive level to the switching transistor to be controlled in response to the peak current in said transistor as well as the output voltage of the blocking oscillator. Furthermore the control circuit allows the blocking oscillator to be turned off during the short period of time after each spark discharge that is needed for turnoff of a switching device used to control that discharge.
    Type: Grant
    Filed: July 6, 1987
    Date of Patent: May 16, 1989
    Inventor: Floyd M. Minks
  • Patent number: 4823525
    Abstract: A skylight structure offering superior water intrusion resistance has a glass plate superposed in spaced relationship above a plastic dome member having an integral inverted U-shaped flange. A cap marginally framing the glass and plastic members has spaced downwardly depending flanges with an inner shorter flange abutting the outer surfaces of the plastic flange and an outer longer flange spaced from and shielding the outer surfaces of the plastic flange. The outside lower end of the U-shaped flange is cured outwardly.
    Type: Grant
    Filed: September 13, 1988
    Date of Patent: April 25, 1989
    Assignee: Tub-Master Corporation
    Inventors: Joseph W. Roberts, John C. Roberts, Gordon MacLeod
  • Patent number: 4821702
    Abstract: This disclosure relates to apparatus for operating a combustion engine by controlling the spark ignition voltage to said engine. Said control is created by the application of two opposing currents to the input of an amplifying device which is used to selectively shunt a constant current source away from the control electrode of a second amplifying device connected to control the formation of said ignition voltage.
    Type: Grant
    Filed: July 29, 1988
    Date of Patent: April 18, 1989
    Inventor: Floyd M. Minks
  • Patent number: 4819630
    Abstract: An optical energy transmission device and a related method includes a flexible fiber optic rod and a flexible sheath surrounding and spaced from the fiber optic rod, with a disc member fixed in edge contact with both the rod and the sheath for supporting and uniformly spacing the rod from the sheath. The inner and outer periphery of the disc is arched in order to permit cooling fluids to pass relatively unimpeded along the passageway along the rod and the outer sheath, while maintaining the desired position of the rod relative to the sheath.
    Type: Grant
    Filed: March 20, 1987
    Date of Patent: April 11, 1989
    Assignee: Laser Photonics, Inc.
    Inventor: Anthony G. DeHart
  • Patent number: 4817940
    Abstract: An exercise monitoring system and method for comparing the present movement of the exercise machine caused by the physical exertion of a user with the user's past movement of the exercise machine. The system includes an exercise monitoring main unit, an exercise monitoring screen, a portable personal memory module, an exercise machine monitor, and an exercise monitoring analyzer. The exercise machine monitor measures the movement of the exercise machine and provides data representative thereof. The portable personal memory provides data representative of the user's past movement of the exercise machine. The exercise monitoring main unit compares the data and generates a pacing signal on the exercise monitoring screen for the user. The user follows the pacing signal to duplicate his previous performance. The exercise monitoring screen discipline the user's present pace compared to his past pace.
    Type: Grant
    Filed: April 4, 1986
    Date of Patent: April 4, 1989
    Assignee: Fike Corporation
    Inventors: Bon F. Shaw, Gary M. Bond
  • Patent number: 4815364
    Abstract: A register for an air duct is made up of extruded L-shaped members that have perpendicular integrally formed frame and duct inset parts locked in butting relationship at mitred ends by flat corner clips with resilient barbs that slip into and bitingly engage channels along the frame parts of adjacent members. End clips slip over the distal edges of the duct inset parts to secure the backs of adjoining members. Curved blades extend horizontally in louver fashion in front of pivotable vertical damper vanes across the register opening to provide airflow control.
    Type: Grant
    Filed: March 6, 1987
    Date of Patent: March 28, 1989
    Assignee: Codisco, Inc.
    Inventors: Robert K. Wagner, Alex L. Homery, Richard C. Asbury, Allen W. Davis, Jr.
  • Patent number: 4812852
    Abstract: The present invention includes both a system and a method for locating a source of a randomly modulated radio signal. In one form of the invention, at least three receiving stations at known locations receive and process the randomly modulated radio signal. A common reference level is selected for the radio signal at each of the receiving stations. The times of arrival at each receiving station of selected transitions of the radio signal with reference to the common reference level are determined. Each receiving station provides an indication of the times of arrival of the selected transitions to a central facility for processing to provide an indication of the location of the signal source.
    Type: Grant
    Filed: February 20, 1987
    Date of Patent: March 14, 1989
    Assignee: Scientific Development Corporation
    Inventors: Rodney B. Bent, Paul W. Casper
  • Patent number: 4812172
    Abstract: Rotary apparatus and a related method for removing foreign and undesirable material from composite cans during the manufacturing operation includes a pair of rotatable plates having an axis of rotation and outwardly-extending fingers faced about the periphery thereof, and a plurality of reciprocating plungers arranged alongside the periphery of the plates and generally parallel with the axis of rotation, the plungers being rotated with the plates about a common drive shaft. The rearward end of each plunger engages a cam race for extending the plungers into and out of composite cans positioned about the periphery of the plate only during a portion of each revolution of rotation of the plate, in order to remove trim ring scrap and other foreign objects from the cans.
    Type: Grant
    Filed: November 6, 1987
    Date of Patent: March 14, 1989
    Assignee: Citrus Central, Inc.
    Inventors: James E. Brock, William R. DeUnger
  • Patent number: D300764
    Type: Grant
    Filed: June 16, 1986
    Date of Patent: April 18, 1989
    Inventor: Samuel E. Duncan
  • Patent number: D301208
    Type: Grant
    Filed: October 28, 1985
    Date of Patent: May 23, 1989
    Assignee: Porta-Nails, Inc.
    Inventor: John Totten
  • Patent number: D301909
    Type: Grant
    Filed: August 8, 1986
    Date of Patent: June 27, 1989
    Inventor: Will Heddon
  • Patent number: D303032
    Type: Grant
    Filed: April 30, 1986
    Date of Patent: August 22, 1989
    Assignee: Carl E. Clements
    Inventor: Carl E. Clements
  • Patent number: D305778
    Type: Grant
    Filed: July 17, 1987
    Date of Patent: January 30, 1990
    Inventor: James W. Caulk