Patents Represented by Attorney Raymond F. MacKay
  • Patent number: 3972681
    Abstract: A flow-through thermal detector for determining the temperature change resulting from a reaction in a fluid stream includes a pair of parallel fluid paths one of which carries the fluid stream in which the reaction occurs while the other carries a similar fluid without the occurrence of a reaction. The detector includes a temperature sensor for each path. The first of the sensors is mounted to sense the temperature of the reacting stream after said reaction has occurred while the second of the sensors is mounted to sense the temperature of the non-reacting stream at a point in its flow path comparable to that at which the first sensor is mounted. A heat shield is provided surrounding the parallel paths and the heat shield is controllable to a predetermined temperature. Preheating of the streams is carried out by a preheating means positioned within the heat shield to receive the fluid stream entering the shield.
    Type: Grant
    Filed: July 14, 1975
    Date of Patent: August 3, 1976
    Assignee: Leeds & Northrup Company
    Inventors: Peter Joseph Clack, Herman Wesley Levin, George Clarence Mergner
  • Patent number: 3953188
    Abstract: There is disclosed a system for controlling the cooling of the molds in a glass forming machine which involves compensating the pressure set point for the control of the cooling air to correct for changes in the temperature of the cooling air and changes in the mass flow rate of the glass. During maximum and minimum flow conditions for the cooling air the heat transfer equilibrium between the coolant and the parisons being cooled is modified as by modifying the set points of the temperature controllers on the feeder supplying the forming machine or alternatively by changing the speed of the forming machine so that the parisons tend to stay at the desired temperature with the limited range of coolant supply.
    Type: Grant
    Filed: May 5, 1975
    Date of Patent: April 27, 1976
    Assignee: Leeds & Northrup Company
    Inventor: Harry A. Fertik
  • Patent number: 3950992
    Abstract: An immersion molten metal sampling device of a type usable to obtain a sample of molten steel from a furnace and to measure the temperature of the molten metal in the furnace. The device includes a high density monolithic ceramic mold capable of obtaining a flat, rectangular shaped sample of the molten metal for spectrographic analysis as well as a pin sample for combustion analysis. The construction of the sampler avoids contamination of the sample by using gas permeable substances that are gaseous inert at the temperature of the molten metal while at the same time eliminating problems due to leakage of the molten metal through vent passages and seams in the mold.
    Type: Grant
    Filed: August 27, 1975
    Date of Patent: April 20, 1976
    Assignee: Leeds & Northrup Company
    Inventor: Richard James Hance
  • Patent number: 3946211
    Abstract: A filter is provided to substantially nullify the effect of process noise of less than a preset amplitude limit on the measurement of a process variable. The filter passes on to a controller or other device all signal changes greater than this amplitude. Within the amplitude limit the signal is damped by a first order lag with a filter time constant typically at least an order of magnitude greater than the average period of the noise to be filtered, but outside the amplitude limit, signal changes are passed immediately with no lag to a device such as a controller. The filter functions by generating a compensating signal essentially duplicating the process noise and then subtracting this compensating signal from the filter input signal, thus canceling this noise from the signal passed to the controller or other device. By subtracting only a limited value of this compensating signal from the filter input, changes of input greater than this limit are not compensated, and are thus immediately passed with no lag.
    Type: Grant
    Filed: July 17, 1974
    Date of Patent: March 23, 1976
    Assignee: Leeds & Northrup Company
    Inventor: Theron W. Jenkins, Jr.
  • Patent number: 3939459
    Abstract: A digital signal linearizer for obtaining a linear digital output from a non-linear input. The output voltage of a thermocouple is converted to a train of pulses by a dual slope analog to digital converter. The number of pulses in the pulse train is proportional to the voltage and is linearized by a pulse rate multiplier programmed to vary over successive ranges of pulse counts corresponding to linear segments approximating the non-linear characteristic relating temperature and voltage. The linearized pulse train out of the multiplier is counted and displayed directly in temperature units.
    Type: Grant
    Filed: January 9, 1974
    Date of Patent: February 17, 1976
    Assignee: Leeds & Northrup Company
    Inventor: Howard S. Hoopes
  • Patent number: 3937615
    Abstract: An auto-ranging glucose measuring system including a device capable of mixing a glucose containing solution and a diluent in a variable ratio, a glucose oxidase enzyme converter column for converting the diluted glucose solution to hydrogen peroxide as one of the products, an amperometric detector for producing an analog electric signal proportional to the concentration of hydrogen peroxide, a high-low limit circuit for producing a pulse output when the analog electric signal is greater than the preset high limit of the linear span of the detector or is less than the preset low limit of the noise level of the detector, an electronic motor speed changing circuit interposed between a source of alternating current and a pump motor in said mixing device, having a frequency dividing network controllable by a register whose contents may be incremented or decremented by a pulse from the high-low limit circuit.
    Type: Grant
    Filed: December 17, 1974
    Date of Patent: February 10, 1976
    Assignee: Leeds & Northrup Company
    Inventors: Peter J. Clack, George R. Moreland