Patents Represented by Attorney F. L. Mehlhoff
  • Patent number: 4235526
    Abstract: A light field liquid crystal display cell with a colored seal and pattern layer applied to the cell substrates. Dark segments are displayed against a lighter background. The light field background is created without masking the cell substrates, polymeric substances can be used to space and seal the cell substrates, and the cell is amenable for the construction of large displays.
    Type: Grant
    Filed: May 7, 1979
    Date of Patent: November 25, 1980
    Assignee: Beckman Instruments, Inc.
    Inventors: Arthur L. Berman, Gordon Kramer
  • Patent number: 4228394
    Abstract: In a digital test instrument such as a digital ohmmeter for measuring and digitally displaying the resistance of an unknown circuit element, there is included an electrical continuity tester coupled to the input of the digital ohmmeter for instantaneously and digitally indicating electrical continuity. Connection of the electrical continuity tester to the input of the digital ohmmeter is achieved in a manner such as to not overload or otherwise affect the accuracy of the resistance measurement.
    Type: Grant
    Filed: November 16, 1978
    Date of Patent: October 14, 1980
    Assignee: Beckman Instruments, Inc.
    Inventor: John B. Crosby
  • Patent number: 4225825
    Abstract: An improved ramp generating circuit which is self-compensating for changes in component performance is disclosed. The circuit is designed to attain a reference voltage in a fixed number of counts as provided by a precision clock source. A single direction compensation feedback network is employed to increase the slope in increments until the desired peak level and clock count are attained simultaneously. Embodiments are shown wherein the circuit is employed in a gas discharge bar graph display driving circuit and as an analog-to-digital converter.
    Type: Grant
    Filed: September 25, 1978
    Date of Patent: September 30, 1980
    Assignee: Beckman Instruments, Inc.
    Inventor: Geoffrey P. Watts
  • Patent number: 4214179
    Abstract: An improved rotor imbalance detector for a centrifuge comprising a rotatable electrically conducting ring; means to support and insulate the conducting ring from the centrifuge spindle shaft, and yet permit rotational movement of the conducting ring with respect to the support means, when the conducting ring is struck by the centrifuge drive spindle during an imbalance condition, means for de-energizing the power supplied to the centrifuge motor which rotates the drive spindle, and an electrically conducting lead in electrical contact with the conducting ring and the de-energizing means.
    Type: Grant
    Filed: March 15, 1979
    Date of Patent: July 22, 1980
    Assignee: Beckman Instruments, Inc.
    Inventors: Kenneth E. Jacobson, William S. Gutierrez
  • Patent number: 4205779
    Abstract: A system of bypass passages adjacent bearing means in the drive system of an ultracentrifuge which operates in a vacuum environment. The bypass passages or channels are designed to prevent the establishment of a pressure differential across the bearings in the drive system when a vacuum is being pulled or exists around the drive system when it is operating. The unique bypass system prevents the loss of lubricating material within the drive system during air evacuation of the drive system and the rotor chamber when a vacuum environment is being established within the rotor chamber. Also, the bypass system promotes a more uniform and constant flow of lubricating medium in the bearings.
    Type: Grant
    Filed: March 14, 1979
    Date of Patent: June 3, 1980
    Assignee: Beckman Instruments, Inc.
    Inventor: Kenneth E. Jacobson
  • Patent number: 4205261
    Abstract: A method and apparatus for detecting the absence of a coded overspeed disk used to indicate the maximum design speed of a rotor which is rotatably connected to a high speed centrifuge. Two donut-shaped coded disks, one mounted on the drive shaft on the centrifuge and the other mounted on the centrifuge rotor are utilized. Optical emitter sensor assemblies are used to produce speed control and overspeed signals. By sensing the light reflected back to the optical sensor from the drive system hub, the rotational speed of the centrifuge is indicated. By sensing the light reflected back to the optical sensor from the overspeed disk mounted on the rotor, the rotation of the rotor is detected. In the absence of an overspeed disk, the speed control frequency will exceed that of the overspeed disk.
    Type: Grant
    Filed: July 13, 1978
    Date of Patent: May 27, 1980
    Assignee: Beckman Instruments, Inc.
    Inventor: Robert C. Franklin
  • Patent number: 4202487
    Abstract: A rotor apparatus utilizing a lid having an enlarged rim portion which under centrifugally induced forces will move into close sealing contact with the lower portion of the rotor. The lid portion of the rotor is a generally flat circular disc with the thicker rim portion of greater mass located around the periphery of the circular disc. The slight deflection of the lid during centrifugation provides an automatic increase in the seal between the lid and the lower portion of the rotor as the rotational speed increases. The automatic tightening feature enables the user to merely hand tighten the lid onto the lower portion of the rotor without having to use some type of mechanical advantage tool. The lid has a relatively large diameter and contains no holes in order to reduce possible material stress in the lid during centrifugation. The lid is threadably connected to the lower portion of the rotor by a depending stud projecting from the bottom surface of the lid.
    Type: Grant
    Filed: February 22, 1978
    Date of Patent: May 13, 1980
    Assignee: Beckman Instruments, Inc.
    Inventor: John R. Edwards
  • Patent number: 4201335
    Abstract: A mechanical overspeed protection device incorporated in a microtest plate carrier used in a centrifuge rotor. A locking arm actuates into a blocking position on the microtest plates in the carrier to indicate that the carriers on the rotor have been subjected to an overspeed condition during the centrifugation run. A housing within the carrier microtest plate retains the arm in an unactivated position during operation below a specified force field. However, when the carrier experiences an overspeed condition, the locking arm is designed to have sufficient weight, so that in response to the centrifugally induced forces the arm will move out of the housing into an outward blocking position on the carrier plates. The insertion of new microtest plates in the carrier for additional centrifugation runs is prevented, since the locking arm is in its blocking position.
    Type: Grant
    Filed: June 5, 1978
    Date of Patent: May 6, 1980
    Assignee: Beckman Instruments, Inc.
    Inventors: Thomas E. Conn, John R. Edwards
  • Patent number: 4196844
    Abstract: A closing structure for the top of a centrifuge chamber comprising a door which is slidable horizontally toward and away from closed position, a retaining member above the door which permits a limited upward movement of the door, side members which surround the closed door on three sides to contain shrapnel from a rotor failure, and a flange extending downwardly from the door on its fourth side to contain shrapnel.
    Type: Grant
    Filed: March 15, 1979
    Date of Patent: April 8, 1980
    Assignee: Beckman Instruments, Inc.
    Inventor: Kenneth E. Jacobson
  • Patent number: 4196959
    Abstract: A carrier strip assembly of continuous length having transversely mounted round lead wires with an integrally formed resilient clamp on each end of each lead wire for connection with an electrical component substrate. The carrier strip provides the transporting means for the attached electrical component substrate for the assembly stages of the electrical component. The lead wires are severed from the carrier strip portion to provide outwardly extending round lead pins or external connects for interface with an electrical circuit assembly. The method for making the carrier strip assembly is disclosed.
    Type: Grant
    Filed: December 27, 1977
    Date of Patent: April 8, 1980
    Assignee: Beckman Instruments, Inc.
    Inventors: James R. Chesemore, Thomas C. Burns
  • Patent number: 4195326
    Abstract: A screen printed capacitor to provide a predetermined temperature coefficient of capacitance. The capacitance device utilizes a common electrode with a uniform dielectric layer in conjunction with two side-by-side base electrodes resulting in opposite polarity temperature coefficient of capacitance values. The proportion of the area of each of the side-by-side base electrodes with respect to each other determines the predetermined temperature coefficient of capacitance required.
    Type: Grant
    Filed: September 12, 1977
    Date of Patent: March 25, 1980
    Assignee: Beckman Instruments, Inc.
    Inventors: Frank A. Ruegg, William A. Vitriol
  • Patent number: 4190195
    Abstract: This invention relates to a swinging bucket centrifuge rotor in which each bucket is supported by an independent bucket hanger member disposed within a cavity in the rotor. Each hanger member is spring biased in a radial direction toward the axis of rotation, and is supported by a guide sleeve with fastening means extending through the guide sleeve. The guide sleeve prevents rotation of the bucket and hanger member with respect to the rotor body.
    Type: Grant
    Filed: March 14, 1979
    Date of Patent: February 26, 1980
    Assignee: Beckman Instruments, Inc.
    Inventor: Steven J. Chulay
  • Patent number: 4182540
    Abstract: A process for making the final seal in a gas discharge display using a piece of low temperature glass cane which is melted to form a generally flat seal within an access hole in one of the insulating plates of the display. The generally elongated piece of cane glass is inserted into an access hole in one of the insulating plates and after being exposed to a melting temperature it fills the access hole area in the insulating plate, leaving no protrusions on the outside surface of the display.
    Type: Grant
    Filed: December 22, 1977
    Date of Patent: January 8, 1980
    Assignee: Beckman Instruments, Inc.
    Inventors: Roger A. Frankland, Henry E. Franklin
  • Patent number: 4177921
    Abstract: An improved multicompartment rotor liner which essentially eliminates the possibility of contamination of centrifugated clarified serum upon retrieval of the serum from the liner. The liner has an annular chamber surrounding a central chamber in which the chyle material is collected during centrifugation from a chylous serum. The present liner invention incorporates a unique flat cover to prevent the accumulation of chyle in the central chamber above the seal junction between the annular chamber and the central chamber. This unique configuration also allows for greater ease of pipette insertion.
    Type: Grant
    Filed: September 29, 1977
    Date of Patent: December 11, 1979
    Assignee: Beckman Instruments, Inc.
    Inventor: Steven T. Nielsen
  • Patent number: 4154125
    Abstract: A device for use with variable electrical components such as potentiometers to provide not only an independent means adjacent the control knob to lock the knob in a fixed position, but also to provide variable amounts of drag on the knob to enhance more precise and accurate control of the knob. The locking device is positioned between the controlled component and the control knob. The locking device can be moved to a plurality of positions adjacent the control knob to vary the amount of drag on the control knob.
    Type: Grant
    Filed: July 5, 1977
    Date of Patent: May 15, 1979
    Assignee: Beckman Instruments, Inc.
    Inventor: Edgar H. Frank
  • Patent number: 4148761
    Abstract: Powder compositions useful for making conductors, e.g. microcircuit conductors, end terminations for capacitors, electrodes for gas discharge display devices, etc. The compositions comprise inorganic powders dispersed in an inert vehicle and are printed and fired in the conventional manner on dielectric substrates. The inorganic powders comprise aluminum, silicon, and glass.
    Type: Grant
    Filed: January 31, 1977
    Date of Patent: April 10, 1979
    Assignee: Beckman Instruments, Inc.
    Inventor: Casimir W. Kazmierowicz
  • Patent number: 4148433
    Abstract: An insert for use with swinging bucket rotors at the interface between the swinging bucket and the rotor arm trunnions which pivotally support the bucket. The insert is designed to decrease the friction between the swinging bucket and the support trunnions.
    Type: Grant
    Filed: June 29, 1977
    Date of Patent: April 10, 1979
    Assignee: Beckman Instruments, Inc.
    Inventor: Brian J. Bayley
  • Patent number: 4147651
    Abstract: Nematic liquid crystal compositions containing 4'-substituted-4-cyanobiphenyl and 4, 4'-disubstituted phenyl benzoate liquid crystal compositions which can be actuated at low voltages, e.g., under 3.5 Vrms in a 12.5 micron thick twisted nematic liquid crystal display.
    Type: Grant
    Filed: September 3, 1974
    Date of Patent: April 3, 1979
    Assignee: Beckman Instruments, Inc.
    Inventor: Chan S. Oh
  • Patent number: 4147294
    Abstract: A carrier assembly for pivotal placement on a swinging carrier rotor wherein the carrier has a support member which maintains the carrier assembly in a centered location between the hinge pins on the rotor. The carrier assembly has a frame unit which holds a microtitration plate containing samples to be centrifugated. The support member in the carrier assembly is slidably engaged with the frame unit and eliminates the need for welds. Each end of the support member has a generally semicircular sleeve portion which provides for the easy placement and removal of the carrier assembly from the rotor hinge pins. Retaining means are positioned on the support member to prevent deflection of the carrier frame unit along the support member during centrifugation.
    Type: Grant
    Filed: February 22, 1978
    Date of Patent: April 3, 1979
    Assignee: Beckman Instruments, Inc.
    Inventors: Howard R. Davidson, Brian J. Bayley
  • Patent number: 4147959
    Abstract: In a multilayer gas-discharge display panel of the type including a plurality of character blocks, each including a plasma supply reservoir section, a control anode section, and a display section, such sections being arranged in a plurality of parallel, gas-filled columns defining a display matrix, the supply reservoir providing a source of ions which are selectively conducted by the control anodes to the display section, a voltage being applied to the display section to initiate a gas breakdown in those columns which have had ions conducted therethrough by the control anodes, an improved display section is disclosed comprising a transparent, insulating plate extending across the front of the panel, perpendicular to and covering all of the columns, a transparent electrode covering the front surface of the plate, on the opposite side of the plate from the supply reservoir and the control anodes, and means for applying voltage pulses of alternating polarity to the electrodes to create a flashing discharge in ea
    Type: Grant
    Filed: May 25, 1977
    Date of Patent: April 3, 1979
    Assignee: Beckman Instruments, Inc.
    Inventor: Theodore H. Bonn