Leeds and Northrup Co
Leeds andActive Patents
0
Total Holdings
126
Patent Holdings
Filter in Explorer →| Patent No. | Title | Status | Filing Date | Grant Date | Claims | Actions |
|---|---|---|---|---|---|---|
| US4114446A | Temperature measurement with three lead resistance thermome… | Expired / Lapsed | 1976-12-13 | 1978-09-19 | 10 | Details |
| US3939459A | Digital signal linearizer | Expired / Lapsed | 1974-01-09 | 1976-02-17 | 4 | Details |
| US3913403A | Temperature measurement with three-lead resistance thermome… | Expired / Lapsed | 1973-10-11 | 1975-10-21 | 14 | Details |
| US3826305A | Temperature controller for controlling both heating and coo… | Expired / Lapsed | 1973-01-10 | 1974-07-30 | 12 | Details |
| US3791793A | Adaptive feed forward-feedback control of the concentration… | Expired / Lapsed | 1972-01-31 | 1974-02-12 | 10 | Details |
| US3771167A | Method for calculating the average value of a noise corrupt… | Expired / Lapsed | 1971-02-02 | 1973-11-06 | 4 | Details |
| US3699318A | Incremental slope method for optimum continuous digital lin… | Expired / Lapsed | 1970-08-19 | 1972-10-17 | 52 | Details |
| US3693067A | Adjustable proportional response for balanceable system | Expired / Lapsed | 1970-08-07 | 1972-09-19 | 5 | Details |
| US3686665A | Digital function generator | Expired / Lapsed | 1969-12-31 | 1972-08-22 | 26 | Details |
| US3629562A | Control for power pools | Expired / Lapsed | 1969-11-25 | 1971-12-21 | 11 | Details |
| US3585603A | Computer trend recorder | Expired / Lapsed | 1968-07-16 | 1971-06-15 | 7 | Details |
| US3555252A | Learning control of actuators in control systems | Expired / Lapsed | 1967-05-11 | 1971-01-12 | 20 | Details |
| US3529293A | Supervisory and control system | Expired / Lapsed | 1967-04-10 | 1970-09-15 | 0 | Details |
| US3527445A | Furnace reversal system | Expired / Lapsed | 1968-07-08 | 1970-09-08 | 0 | Details |
| US3516063A | Supervisory and control system having buffer storage input … | Expired / Lapsed | 1966-05-09 | 1970-06-02 | 0 | Details |
| US3515343A | Correction entry circuit | Expired / Lapsed | 1966-03-14 | 1970-06-02 | 0 | Details |
| US3493930A | Supervisory control system having four status reporters | Expired / Lapsed | 1966-03-23 | 1970-02-03 | 0 | Details |
| US3452329A | Supervisory control system | Expired / Lapsed | 1964-11-16 | 1969-06-24 | 0 | Details |
| US3450867A | Estimated tap temperature calculator for basic oxygen furna… | Expired / Lapsed | 1966-03-14 | 1969-06-17 | 2 | Details |
| US3419772A | Probabilistic and deterministic filter for control systems | Expired / Lapsed | 1964-09-25 | 1968-12-31 | 0 | Details |
| US3411850A | Electronic radiant energy pyrometers | Expired / Lapsed | 1962-03-05 | 1968-11-19 | 1 | Details |
| US3405279A | Digital power generation control system | Expired / Lapsed | 1965-06-04 | 1968-10-08 | 0 | Details |
| US3392272A | Minimum input dispatch computer | Expired / Lapsed | 1963-06-03 | 1968-07-09 | 1 | Details |
| US3389397A | Analog centesimal recorder having redundant digit | Expired / Lapsed | 1967-03-03 | 1968-06-18 | 0 | Details |
| US3329311A | Mass-flow rate control | Expired / Lapsed | 1965-11-22 | 1967-07-04 | 4 | Details |
| US3270253A | Automatic interlock system | Expired / Lapsed | 1964-09-03 | 1966-08-30 | 1 | Details |
| US3214764A | Digital-analog recorder system | Expired / Lapsed | 1963-02-08 | 1965-10-26 | 2 | Details |
| US3200343A | D.c. amplifier having fast recovery characteristics | Expired / Lapsed | 1961-12-29 | 1965-08-10 | 1 | Details |
| US3145374A | High-speed measuring system | Expired / Lapsed | 1958-10-17 | 1964-08-18 | 2 | Details |
| US3024295A | Immersion pyrometer with non-directional contact structure | Expired / Lapsed | 1959-06-16 | 1962-03-06 | 0 | Details |
| US2901563A | Negative feedback amplifiers | Expired / Lapsed | 1958-09-09 | 1959-08-25 | 0 | Details |
| US2895056A | Frequency-biased control systems for electrical generating … | Expired / Lapsed | 1957-07-08 | 1959-07-14 | 0 | Details |
| US2866102A | Systems for computing and controlling the generation of int… | Expired / Lapsed | 1956-09-11 | 1958-12-23 | 0 | Details |
| US2836731A | Generation control system | Expired / Lapsed | 1954-08-16 | 1958-05-27 | 0 | Details |
| US2830252A | Arrangements for providing standardized voltage or current | Expired / Lapsed | 1954-08-02 | 1958-04-08 | 0 | Details |
| US2823577A | Multiple slit spectrograph for direct reading spectrographi… | Expired / Lapsed | 1951-08-10 | 1958-02-18 | 0 | Details |
| US2815500A | Monitoring system for continuously selecting extreme variab… | Expired / Lapsed | 1955-12-14 | 1957-12-03 | 0 | Details |
| US2788702A | Measurement of light scattering | Expired / Lapsed | 1951-09-24 | 1957-04-16 | 0 | Details |
| US2773994A | Control of electrical generation | Expired / Lapsed | 1953-03-26 | 1956-12-11 | 0 | Details |
| US2759354A | Isothermal systems for gas analysis | Expired / Lapsed | 1950-09-26 | 1956-08-21 | 2 | Details |
| US2754429A | Load control systems for generating units | Expired / Lapsed | 1951-02-19 | 1956-07-10 | 0 | Details |
| US2750836A | Monochromator system for spectrochemical analysis | Expired / Lapsed | 1954-07-27 | 1956-06-19 | 2 | Details |
| US2724022A | Fast-acting feedback amplifiers for high impedance sources | Expired / Lapsed | 1950-02-07 | 1955-11-15 | 0 | Details |
| US2714894A | Transfer from auxiliary to automatic control in pressure-ac… | Expired / Lapsed | 1952-06-20 | 1955-08-09 | 0 | Details |
| US2692342A | Apparatus and method for control of electrical generation | Expired / Lapsed | 1953-06-04 | 1954-10-19 | 0 | Details |
| US2679979A | Boiler load control | Expired / Lapsed | 1950-03-24 | 1954-06-01 | 0 | Details |
| US2674719A | Temperature-compensating measuring system | Expired / Lapsed | 1950-10-18 | 1954-04-06 | 0 | Details |
| US2673136A | Multirange measuring system | Expired / Lapsed | 1948-09-22 | 1954-03-23 | 0 | Details |
| US2668264A | Measuring system of the balanceable network type | Expired / Lapsed | 1952-04-24 | 1954-02-02 | 0 | Details |
| US2666171A | Electric motor control system with reduced cross-dependence… | Expired / Lapsed | 1951-08-28 | 1954-01-12 | 0 | Details |
| US2666170A | Rate and reset rebalanceable control system | Expired / Lapsed | 1950-03-15 | 1954-01-12 | 0 | Details |
| US2657376A | Control system for multiple-point measuring instrument | Expired / Lapsed | 1949-12-23 | 1953-10-27 | 0 | Details |
| US2638811A | Pulse amplifier system for spectrographic analysis | Expired / Lapsed | 1950-04-22 | 1953-05-19 | 0 | Details |
| US2627182A | Aspiration pyrometer | Expired / Lapsed | 1949-12-14 | 1953-02-03 | 0 | Details |
| US2622192A | Measuring system with grid current suppressor | Expired / Lapsed | 1949-01-06 | 1952-12-16 | 0 | Details |
| US2586603A | Electronic recording and controlling apparatus | Expired / Lapsed | 1949-08-08 | 1952-02-19 | 0 | Details |
| US2586686A | Oscillator-controlled rebalance measuring system | Expired / Lapsed | 1947-02-24 | 1952-02-19 | 0 | Details |
| US2584954A | Self-balancing electrical system and method | Expired / Lapsed | 1948-05-08 | 1952-02-05 | 0 | Details |
| US2565249A | High-temperature-measuring system | Expired / Lapsed | 1945-08-20 | 1951-08-21 | 0 | Details |
| US2547105A | System for measurement of small currents | Expired / Lapsed | 1946-12-18 | 1951-04-03 | 0 | Details |
| US2505981A | Pneumatic control system | Expired / Lapsed | 1945-12-01 | 1950-05-02 | 0 | Details |
| US2496860A | Control system | Expired / Lapsed | 1945-11-23 | 1950-02-07 | 0 | Details |
| US2493078A | Immersion unit for radiation pyrometers | Expired / Lapsed | 1945-08-20 | 1950-01-03 | 0 | Details |
| US2485948A | Low-frequency converter-amplifier system | Expired / Lapsed | 1947-01-31 | 1949-10-25 | 0 | Details |
| US2464639A | Magnetic amplifier | Expired / Lapsed | 1945-04-13 | 1949-03-15 | 0 | Details |
| US2441226A | Measurement of telemetric signals during time spaces thereb… | Expired / Lapsed | 1944-03-23 | 1948-05-11 | 0 | Details |
| US2416949A | Cell for ph measurements | Expired / Lapsed | 1942-06-10 | 1947-03-04 | 0 | Details |
| US2371732A | Electrical control system | Expired / Lapsed | 1942-08-27 | 1945-03-20 | 0 | Details |
| US2367746A | Electrical measuring system | Expired / Lapsed | 1942-09-10 | 1945-01-23 | 0 | Details |
| US2362661A | Telemetric system | Expired / Lapsed | 1942-02-19 | 1944-11-14 | 0 | Details |
| US2336929A | Telemetric system | Expired / Lapsed | 1942-06-19 | 1943-12-14 | 0 | Details |
| US2325308A | Electrical system | Expired / Lapsed | 1942-04-22 | 1943-07-27 | 0 | Details |
| US2325232A | Control system | Expired / Lapsed | 1941-11-07 | 1943-07-27 | 0 | Details |
| US2318197A | Visual indicator | Expired / Lapsed | 1942-05-05 | 1943-05-04 | 0 | Details |
| US2312945A | Measuring system | Expired / Lapsed | 1937-03-02 | 1943-03-02 | 0 | Details |
| US2300537A | Control system | Expired / Lapsed | 1940-06-03 | 1942-11-03 | 0 | Details |
| US2285540A | Control system | Expired / Lapsed | 1939-07-01 | 1942-06-09 | 0 | Details |
| US2285482A | Method of and apparatus for measuring | Expired / Lapsed | 1939-02-24 | 1942-06-09 | 0 | Details |
| US2277849A | Electrical control system | Expired / Lapsed | 1938-08-15 | 1942-03-31 | 0 | Details |
| US2252015A | Optical pyrometry | Expired / Lapsed | 1938-03-28 | 1941-08-12 | 0 | Details |
| US2199082A | Radiation pyrometry | Expired / Lapsed | 1938-10-22 | 1940-04-30 | 0 | Details |
| US2154065A | Electrical measuring system | Expired / Lapsed | 1935-08-07 | 1939-04-11 | 0 | Details |
| US2124725A | Electrical generating system | Expired / Lapsed | 1935-06-19 | 1938-07-26 | 0 | Details |
| US2124684A | Recorder and control system | Expired / Lapsed | 1932-04-01 | 1938-07-26 | 0 | Details |
| US2119061A | Control method and apparatus | Expired / Lapsed | 1936-05-01 | 1938-05-31 | 0 | Details |
| US2113748A | Exhibiting instrument | Expired / Lapsed | 1936-04-18 | 1938-04-12 | 0 | Details |
| US2113069A | Indicating, recording, and/or controlling apparatus | Expired / Lapsed | 1936-04-18 | 1938-04-05 | 0 | Details |
| US2113436A | Measuring system | Expired / Lapsed | 1934-07-25 | 1938-04-05 | 0 | Details |
| US2113164A | Recorder and control circuits | Expired / Lapsed | 1932-09-22 | 1938-04-05 | 0 | Details |
| US2102030A | Electrical measuring system | Expired / Lapsed | 1935-06-11 | 1937-12-14 | 0 | Details |
| US2098650A | Temperature measuring system | Expired / Lapsed | 1935-11-27 | 1937-11-09 | 0 | Details |
| US2081184A | Electric circuit controller | Expired / Lapsed | 1935-01-23 | 1937-05-25 | 0 | Details |
| US2074118A | Recorder | Expired / Lapsed | 1934-03-08 | 1937-03-16 | 0 | Details |
| US2065365A | Measuring system | Expired / Lapsed | 1934-10-29 | 1936-12-22 | 0 | Details |
| US2054411A | System of distribution | Expired / Lapsed | 1931-10-28 | 1936-09-15 | 0 | Details |
| US2053061A | Combustion control system | Expired / Lapsed | 1934-08-09 | 1936-09-01 | 0 | Details |
| US2050629A | Electric telemetering system | Expired / Lapsed | 1934-05-11 | 1936-08-11 | 0 | Details |
| US2045970A | Electrical measuring | Expired / Lapsed | 1933-06-29 | 1936-06-30 | 0 | Details |
| US2032455A | Voltage regulating system | Expired / Lapsed | 1934-09-13 | 1936-03-03 | 0 | Details |
| US2025134A | Program control of nitriding | Expired / Lapsed | 1932-03-15 | 1935-12-24 | 0 | Details |
| US2007556A | Measuring apparatus | Expired / Lapsed | 1932-07-23 | 1935-07-09 | 0 | Details |
| US2003681A | Measuring apparatus | Expired / Lapsed | 1930-01-28 | 1935-06-04 | 0 | Details |
| US1995594A | Telemetric measuring system | Expired / Lapsed | 1931-08-29 | 1935-03-26 | 0 | Details |
| US1993527A | Fluid measuring system | Expired / Lapsed | 1931-06-30 | 1935-03-05 | 0 | Details |
| US1984920A | Method and apparatus for controlling alternating current ge… | Expired / Lapsed | 1931-05-09 | 1934-12-18 | 0 | Details |
| US1951035A | Apparatus for recording and controlling | Expired / Lapsed | 1928-03-23 | 1934-03-13 | 0 | Details |
| US1935732A | Electrical measuring apparatus | Expired / Lapsed | 1932-06-02 | 1933-11-21 | 0 | Details |
| US1931852A | Control method and apparatus | Expired / Lapsed | 1929-03-14 | 1933-10-24 | 0 | Details |
| US1916352A | Transformer | Expired / Lapsed | 1932-02-02 | 1933-07-04 | 0 | Details |
| US1912997A | Conductivity cell | Expired / Lapsed | 1929-09-23 | 1933-06-06 | 0 | Details |
| US1898209A | Control system and apparatus | Expired / Lapsed | 1928-10-19 | 1933-02-21 | 0 | Details |
| US1845231A | Method of ascertaining the amount of coating on material | Expired / Lapsed | 1929-11-20 | 1932-02-16 | 0 | Details |
| US1834267A | Speed control system | Expired / Lapsed | 1926-06-03 | 1931-12-01 | 0 | Details |
| US1830333A | Control method and apparatus | Expired / Lapsed | 1928-07-07 | 1931-11-03 | 0 | Details |
| US1795753A | Program-controlling system | Expired / Lapsed | 1926-11-03 | 1931-03-10 | 0 | Details |
| US1775540A | Control system | Expired / Lapsed | 1926-06-18 | 1930-09-09 | 0 | Details |
| US1665397A | Electrical measuring apparatus | Expired / Lapsed | 1923-05-09 | 1928-04-10 | 0 | Details |
| US1643582A | Temperature-responsive apparatus | Expired / Lapsed | 1924-08-29 | 1927-09-27 | 0 | Details |
| US1537281A | Electrical measuring apparatus | Expired / Lapsed | 1923-04-28 | 1925-05-12 | 0 | Details |
| US1513558A | Method of and apparatus for determining ion concentration | Expired / Lapsed | 1924-05-16 | 1924-10-28 | 0 | Details |
| US1494586A | Method of and apparatus for measuring temperatures | Expired / Lapsed | 1921-02-26 | 1924-05-20 | 0 | Details |
| US1379266A | Compensation method and apparatus | Expired / Lapsed | 1920-05-05 | 1921-05-24 | 0 | Details |
| US1361676A | Measuring and indicating apparatus | Expired / Lapsed | 1919-02-21 | 1920-12-07 | 0 | Details |
| US1332182A | System of automatic control | Expired / Lapsed | 1917-08-01 | 1920-02-24 | 0 | Details |
| US1199724A | Electrical measuring apparatus. | Expired / Lapsed | 1916-04-26 | 1916-09-26 | 0 | Details |
| US955191A | Resistance-thermometer. | Expired / Lapsed | 1908-11-21 | 1910-04-19 | 0 | Details |