Patents Assigned to Conrac Corporation
  • Patent number: 4943904
    Abstract: The specification discloses a physically compact, low-inductance, high power-factor D.C. power unit assembly for producing rectified, multi-phase or single-phase, full-wave voltage. The assembly includes a plurality of single-phase, full-wave D.C. power units each having a planar rectified pad oriented perpendicular to the plane of the coil turns. The D.C. power units are aligned so that the rectified pads are coplanar. A common bus overlies and is electrically insulated from the rectified pads and is connected to the common terminal of each D.C. power unit. A pair of rectified buses are positioned on opposite sides of, and parallel to, the common bus. Each rectified pad is electrically connected at opposite ends to each of the rectified buses. The common bus is coaxial with the two rectified buses to permit an optimal power factor.
    Type: Grant
    Filed: January 24, 1989
    Date of Patent: July 24, 1990
    Assignee: Conrac Corporation
    Inventors: Stanley R. Van Antwerp, Mark B. Siehling
  • Patent number: 4803754
    Abstract: A door holder-closer comprising a conventional door closer and a novel electromechanical door holder attached to the drive spindle of the door closer. The door holder features a lever which is coupled to the drive spindle of the door closer by an adjustable clamp comprising mating rotor and cone elements. Both the rotor and the cone are seated over the drive spindle with the cone being fixed to the spindle. The rotor is formed with a projecting rotor tab which is selectively engaged by a pawl. The lever is formed with a notch which selectively engages a roller driven by an electromagnet-actuated armature. The motion of the door closer spindle is restrained by a primary latch formed when the roller is seated within the lever notch in response to an energized electromagnet, and by a secondary latch formed when the pawl engages the rotor tab. The primary latch supports and controls the secondary latch. Hold-open door control occurs when both latches are in effect concurrently.
    Type: Grant
    Filed: May 5, 1987
    Date of Patent: February 14, 1989
    Assignee: Conrac Corporation
    Inventor: Frank D. Roberts
  • Patent number: 4705992
    Abstract: A system for stabilizing the cathode emissions of an in-line gun cathode ray tube includes subsystems functionally identical to one another linked to each of the cathodes of an in-line gun cathode ray tube. During the time that the CRT beam is retracing vertically, each subsystem imposes a fixed, predetermined voltage on a cathode in the cathode ray tube, samples the current flowing to the cathode, compares the sampled current to a predetermined, desired reference current for the cathode, develops a differential signal representing the difference, if any, between the sampled current and the reference current, and then drives the current flowing to the cathode from its actual value to its predetermined, reference value so as to maintain a predetermined, desired ratio of the currents flowing to each of the cathodes.
    Type: Grant
    Filed: November 21, 1985
    Date of Patent: November 10, 1987
    Assignee: Conrac Corporation
    Inventor: Dan N. Ciocan
  • Patent number: 4700218
    Abstract: An automated system for adjustment of the white balance in a signal displayed on the screen of a color CRT includes a device attachable to the screen of a color CRT for detecting a first value for at least one of the following signal characteristics: Contrast, brightness, red/green/blue lowlights and red/green/blue highlights in a signal displayed on the screen; a mechanism for changing the first value to a second value within the control range of the CRT; a mechanism for detecting such a second value; a mechanism for storing at least one value within the control range of the CRT for at least one of the foregoing signal characteristics; a mechanism for recovering any such stored value; and a mechanism for conforming the value of one or more of such signal characteristics to a stored value.
    Type: Grant
    Filed: April 12, 1985
    Date of Patent: October 13, 1987
    Assignee: Conrac Corporation
    Inventors: Paul M. Thomsen, Dan N. Ciocan
  • Patent number: 4682000
    Abstract: The specification discloses a lightweight, compact welding transformer particularly well suited for robotic applications. The transformer includes coplanar secondary pads, a parallel common bus, and a secondary coil having turns each including a first end coupled to the common bus and a second end extending through the common bus and coupled to one of the secondary pads. The transformer further includes planar diodes abutting the secondary pads opposite the coil and a planar rectified bus abutting the diodes to sandwich them against the secondary pads.
    Type: Grant
    Filed: March 18, 1985
    Date of Patent: July 21, 1987
    Assignee: Conrac Corporation
    Inventors: Gary E. Holt, Mark B. Siehling, Stanley R. Van Antwerp
  • Patent number: 4238679
    Abstract: A housing assembly of interlocking parts for a dual-chamber ionization smoke detector in which the assembly has a single universal smoke detector head that can be readily twist-locked in one of a plurality of selectable adapter bases appropriate for a particular power source. The smoke detector head includes an interlocking assembly of an ionization chamber module protectively housed between an adapter base cover and a smoke detector cover. The detector head may be removed as a single subassembly from a particular adapter base, and additionally the detector head may be readily disassembled to remove the ionization chamber module for repair or replacement. The smoke detector cover has a dish-like configuration formed with an integral frusto-conical section. The interior of this section is formed with smoke deflector ribs. The cover protectively covers both the ionization smoke chamber and the adapter base.
    Type: Grant
    Filed: December 7, 1978
    Date of Patent: December 9, 1980
    Assignee: Conrac Corporation
    Inventors: John M. Macmillan, Hilario S. Costa
  • Patent number: 4127840
    Abstract: The limited temperature range for operation of conventional semiconductive force transducers is greatly extended in both directions, typically attaining a range from about 4.degree. Kelvin to at least about 400.degree. C. A piezoresistive strain gage is typically formed in a monocrystalline layer of semiconductive material grown epitaxially to a thickness of only a few microns on a monocrystalline support member which has high inherent resistivity and serves directly as force responsive member. For example, silicon is grown epitaxially on one face of a sapphire pressure responsive diaphragm with suitably oriented crystal axes. The diaphragm is typically mounted in hermetically sealed relation on an alumina support with an interlayer of fused glass having selected properties. Transition from the alumina support to a conventional housing is preferably made via a metal such as Kovar in described configuration.
    Type: Grant
    Filed: February 22, 1977
    Date of Patent: November 28, 1978
    Assignee: Conrac Corporation
    Inventor: J. Hardy House
  • Patent number: 4110561
    Abstract: Communication units for hand-held use, combining a microphone for voice communication with means for generating at least two code frequencies for signaling, are made more compact and economical by dual capability of a single amplifying circuit in oscillating mode for tone generation and in substantially linear mode for amplifying the microphone output.
    Type: Grant
    Filed: July 20, 1977
    Date of Patent: August 29, 1978
    Assignee: Conrac Corporation
    Inventor: Joe F. Guess
  • Patent number: 4090030
    Abstract: Apparatus for mounting a radio antenna of whip type on a vehicle is improved to permit more convenient and reliable electrical connection of the antenna assembly directly to the coaxial transmission cable. A particular advantage of the improved structure is that installation and connection of the antenna does not require trimming, soldering or otherwise manipulating the cable conductors. Installation of antennas by inexperienced amateurs is thereby greatly facilitated.
    Type: Grant
    Filed: December 9, 1976
    Date of Patent: May 16, 1978
    Assignee: Conrac Corporation
    Inventor: Eugene F. Lagasse
  • Patent number: 4087799
    Abstract: A particulate products of combustion detector having a light emitting diode and a photovoltaic solar cell coupled one to the other to serve as a particulate or smoke sensor. A free-running multivibrator periodically pulses the light emitting diode to corresponding pulses of light emission having a first pulse-repetition frequency of about 80 Hz. and a duty cycle of about five percent. The output of the solar cell is connected to the input of a ringing amplifier to generate at the amplifier output a ringing pulse sequence having the same pulse-repetition frequency as that of the light element emissions in response to the detection of the particulate products of combustion. The ringing amplifier has a passband of about 500 Hz. centered about a frequency of about 1000 Hz. A detector is connected to the output of the ringing amplifier to generate a peak voltage responsive and proportional to the greatest voltage amplitude of each ringing pulse, namely, that of the first half-cycle of each ringing pulse.
    Type: Grant
    Filed: July 8, 1976
    Date of Patent: May 2, 1978
    Assignee: Conrac Corporation
    Inventor: Frans Brouwer
  • Patent number: 4045620
    Abstract: Individual tones in a tone burst of limited duration are discriminated by repeatedly counting clock pulses during a definite selected number of tone cycles to produce a count summation. The selected number of cycles in each summation is so chosen that a clock frequency of relatively small value will produce a large enough count to insure clear discrimination between the input tones to be distinguished. At the same time, the invention provides a large enough number of distinct count summations to permit rigorous validation of each received tone. The available number of count summations is greatly increased by permitting successive summations to include several tone cycles in common.
    Type: Grant
    Filed: May 10, 1976
    Date of Patent: August 30, 1977
    Assignee: Conrac Corporation
    Inventor: James E. Westbrook
  • Patent number: D246899
    Type: Grant
    Filed: April 1, 1977
    Date of Patent: January 10, 1978
    Assignee: Conrac Corporation
    Inventor: Elmer M. Bruce
  • Patent number: D260498
    Type: Grant
    Filed: February 9, 1979
    Date of Patent: September 1, 1981
    Assignee: Conrac Corporation
    Inventors: John M. Macmillan, Hilario S. Costa