Patents by Inventor Ernest A. Dahl

Ernest A. Dahl 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: 5568130
    Abstract: An apparatus for detecting fire including a light source for generating light, a light sensor for receiving light from the light source and providing an analog signal representing the intensity of the received light, and a clear plastic light guide for transmitting the light from the light source to the sensor. The light guide include notches for allowing smoke to enter the notches. Smoke entering the notches decreases the intensity of the light passing therethrough. A calibration sensor is included. The sensitivity of the fire detector is increased by a lens assembly which collimates the light generated by the light source. The color of smoke entering the light guide may be determined by generating colored light. Temperature, humidity and carbon monoxide levels are also detected and the information is integrated with the smoke detection data to provide a reliable fire detector.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: October 22, 1996
    Inventor: Ernest A. Dahl
  • Patent number: 5550474
    Abstract: The device uses a sensor probe in which a plurality of electrolyte level sensor coils and/or specific gravity stratification indicators are stacked vertically in the walls of a hollow electrically insulating and chemically nonreactive elongated probe housing such that the sensor coils never come into contact with the electrolyte. Balanced transformers or series resonant coils are used to sense changes in electrolyte level and/or changes in specific gravity at various respective levels to indicate stratification of electrolyte. The fields of the sensors are changed by the amount of electrolyte in the area of the sensor coils. These changes operate to produce signals that are read as digital or analog outputs.
    Type: Grant
    Filed: May 3, 1985
    Date of Patent: August 27, 1996
    Inventor: Ernest A. Dahl
  • Patent number: 5486811
    Abstract: Early fire detection and extinguishment is provided by a plurality of fire etection units, each associated with a localized portion of a protected space and including condition sensors specifically appropriate to the environment of that localized portion of a protected space by a selected combination of condition sensors. A fire alarm annunciator and at least one controlled fire extinguishment system portion, or a stand-alone fire extinguishment system, is provided for each fire detection unit. A central control unit preferably includes a profile detector which evaluates outputs of one or more condition sensors over time to reduce false alarm rates while increasing sensitivity to early stage fires.
    Type: Grant
    Filed: February 9, 1994
    Date of Patent: January 23, 1996
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: John P. Wehrle, Ernest A. Dahl, James R. Lugar
  • Patent number: 4857894
    Abstract: An elongated level sensor system has an optical prism formation moulded or ut in a side, and includes a plurality of LED light sources and corresponding photocells positioned along its length. Light from the LED sources are reflected off the prism surfaces to respective photocells when there is no liquid present in the area, thereby indicating "no liquid media present." When liquid surrounds a particular section, light from the LED is not reflected from the prism surfaces, but is refracted out; the change in photocell voltage then indicates the presence of liquid media. The system can be used in a plurality of liquid storage areas, and read out simultaneously at a remote sensor/alarm panel.
    Type: Grant
    Filed: June 27, 1988
    Date of Patent: August 15, 1989
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Ernest A. Dahl
  • Patent number: 4832195
    Abstract: A compact storage file for box-like objects such as the IBM 3480 magnetic tape cartridge. The basic file unit comprises a U-shaped frame of a flat back wall and integral side walls with a plurality of shelves therein. The construction of the basic unit enables it to be replicated and arranged in many different multiples of the basic unit for efficient use of space in large or complex computer facilities. The shelves in the units are vertically spaced close together for the compact storage of the cartridges and arranged to provide for convenient hand removal of the cartridges from the file. Only the shelves of the storage file units are provided with cartridge separating walls which are constructed and arranged so that a grasped group of the IBM 3480 cartridges are easily quickly inserted as a group in any open area of the file unit.
    Type: Grant
    Filed: May 2, 1988
    Date of Patent: May 23, 1989
    Inventor: Ernest A. Dahl
  • Patent number: 4643496
    Abstract: A cabinet arrangement for the storage and use of cassette-like objects such as microfilm boxes or data tape cartridges with the cabinet in one form intended to be placed upon a table adjacent a person's work station, and in another stacked form intended to be used from a floor position. The cabinet arrangement comprises a plurality of open-faced boxes individually rotatively mounted on a swivel base assembly. The boxes can be aligned in any combination of the open-faced sides facing outwardly for access to the microfilm boxes or inwardly for prevented access to the cassette-like objects. A number of constructions are shown for fixing the boxes against rotation in any such combination.
    Type: Grant
    Filed: November 1, 1985
    Date of Patent: February 17, 1987
    Inventor: Ernest A. Dahl
  • Patent number: 4565748
    Abstract: The invention consists of an electromagnetic-field pump. Electrolyte which is an electromagnetic conductor can be stirred and pumped by forcing a field through the electrolyte to magnetically charge the electrolyte and making use of magnetic force exerted on the charged electrolyte by a magnetic field to move the electrolyte. There are no moving parts in the device, only the changing magnetic fields. The magnetic pump assembly is submerged in an electrolyte and consists of an open ended tubular nonmagnetic chamber through which the electrolyte is forced to move in response to changing magnetic fields from external coils which are positioned about the exterior of the tubular chamber and operated to sequentially change in phase.
    Type: Grant
    Filed: January 31, 1985
    Date of Patent: January 21, 1986
    Inventor: Ernest A. Dahl
  • Patent number: 4389608
    Abstract: A lightweight, efficient, transformerless battery-charging system especially for use with electric vehicles, wherein a switching regulator stores only a fraction of the energy in each charging pulse, and much of the charging energy is supplied directly from the powerline and never stored in the charger. Major components include an overload and ground-fault protective current interruptor, an RF interference filter and line rectifier, and a switching regulator capable of maintaining a constant-current constant-voltage output, providing controlled input current throughout the AC cycle and including means for external shutdown.
    Type: Grant
    Filed: September 30, 1981
    Date of Patent: June 21, 1983
    Inventors: Ernest A. Dahl, George H. Barry
  • Patent number: 4388584
    Abstract: A battery cell controlled charging system, consisting of a display unit, battery cell probes, a battery charger and circuitry for controlling the charger, monitors the specific gravity, electrolyte level and temperature control of each cell in a multi-cell lead-acid battery and uses the information to automatically charge the battery when a cell or cells become out of specification while restricting overcharging which is damaging to cells.
    Type: Grant
    Filed: October 23, 1981
    Date of Patent: June 14, 1983
    Inventors: Ernest A. Dahl, George H. Barry
  • Patent number: 4329406
    Abstract: A transducer and battery performance indicator which senses various levels of specific gravity and other conditions of a liquid or electrolyte of varying degrees of translucency and converts the measurements into electrical analog signals which are fed to an indicator read-out. The device may include temperature and level sensors, as well as an agitator for circulating electrolyte, and a number of them are used remotely to monitor a bank of batteries.
    Type: Grant
    Filed: March 27, 1981
    Date of Patent: May 11, 1982
    Inventors: Ernest A. Dahl, George H. Barry
  • Patent number: 4284951
    Abstract: Apparatus for indicating the level of the electrolyte in a battery cell. A three-electrode sensor probe having the electrodes partially embedded in an electrically insulating housing suspended in the electrolyte so that a portion of the probe is immersed in the electrolyte. The electrolyte provides the only conduction path between the electrodes so that the resistance between the electrodes varies according to the level of the electrolyte. An AC or pulsed DC sensing signal is applied between two of the electrodes and an output signal related to the level of the electrolyte is produced. A polarizing current is applied to the other electrode to prevent the buildup of surface contamination on the two sensing electrodes due to the sensing signal.
    Type: Grant
    Filed: August 15, 1979
    Date of Patent: August 18, 1981
    Inventors: Ernest A. Dahl, George H. Barry
  • Patent number: 4217645
    Abstract: A system for automatically monitoring a plurality of parameters of a plurality of cells in a lead-acid storage battery system. A transponder means responsive to a frequency pattern corresponding to a digital command is located at each cell to be monitored and includes a plurality of sensors which provide analog signals having an amplitude related to the value of the parameters being monitored. In a remote scanner/display means, a microprocessor generates a digital interrogation command (containing a transponder address, sensor selection, and reply duration commands) which is converted to a frequency pattern and coupled to the transponder. In response to the command, the transponder couples the analog signal from the selected sensor to a voltage-controlled oscillator and the output of the oscillator is coupled for the selected reply duration to the scanner/display means where the frequency of the signal is determined under the control of the processor.
    Type: Grant
    Filed: April 25, 1979
    Date of Patent: August 12, 1980
    Inventors: George H. Barry, Ernest A. Dahl
  • Patent number: 3996579
    Abstract: A battery electrolyte level indicator for indicating when the electrolyte of a wet cell battery has fallen below a minimum acceptable level. A probe pair is disposed in each cell of the battery to a depth corresponding to the minimum acceptable level of the electrolyte contained therein. The probe pairs are connected in series with a light emitting diode connected between the probe pairs in the end battery cells. The series connected probe pairs and the light emitting diode form a complete circuit loop. Current limiting resistors bridge each probe pair such that when the electrolyte level in any one cell is below the minimum acceptable level, the current limiting resistor replaces the probe pair in the complete circuit loop, thus turning off the light emitting diode.
    Type: Grant
    Filed: November 26, 1975
    Date of Patent: December 7, 1976
    Inventor: Ernest A. Dahl
  • Patent number: 3938018
    Abstract: A normal 117-volt, 60 cycle source is converted into a high frequency signal resulting in radiation of a substantial portion of the energy in the signal. A receiving coil is inductively coupled to the radiation over a given distance substantially less than a wave length of the high frequency signal to provide a received signal without the necessity of any electrical wires. The received signal in turn is converted into a D.C. signal and passed to a rechargeable battery for charging. The inductive coupling can be utilized for recharging portable electrical instruments having rechargeable batteries or for charging larger rechargeable batteries such as used in electrically driven vehicles.
    Type: Grant
    Filed: September 16, 1974
    Date of Patent: February 10, 1976
    Inventor: Ernest A. Dahl