International Business Machines Corp
InternatioActive Patents
0
Total Holdings
184
Patent Holdings
Filter in Explorer →| Patent No. | Title | Status | Filing Date | Grant Date | Claims | Actions |
|---|---|---|---|---|---|---|
| US4371932A | I/O Controller for transferring data between a host process… | Expired / Lapsed | 1981-11-25 | 1983-02-01 | 14 | Details |
| US4314244A | Multiple height proportioned character generation | Expired / Lapsed | 1980-06-16 | 1982-02-02 | 12 | Details |
| US4313161A | Shared storage for multiple processor systems | Expired / Lapsed | 1979-11-13 | 1982-01-26 | 15 | Details |
| US4186438A | Interactive enquiry system | Expired / Lapsed | 1977-03-16 | 1980-01-29 | 13 | Details |
| US4164668A | Method of correcting the voltage coefficient of resistors i… | Expired / Lapsed | 1977-05-12 | 1979-08-14 | 8 | Details |
| US4155117A | Synchronizing channel-to-channel adapter | Expired / Lapsed | 1977-07-28 | 1979-05-15 | 14 | Details |
| US4144563A | Microprocessor system | Expired / Lapsed | 1977-11-21 | 1979-03-13 | 12 | Details |
| US4142234A | Bias filter memory for filtering out unnecessary interrogat… | Expired / Lapsed | 1977-11-28 | 1979-02-27 | 23 | Details |
| US4136386A | Backing store access coordination in a multi-processor syst… | Expired / Lapsed | 1977-10-06 | 1979-01-23 | 15 | Details |
| US4129853A | Method and apparatus for producing compensated signals for … | Expired / Lapsed | 1977-09-26 | 1978-12-12 | 25 | Details |
| US4044244A | Automatic tester for complex semiconductor components inclu… | Expired / Lapsed | 1976-08-06 | 1977-08-23 | 17 | Details |
| US4041461A | Signal analyzer system | Expired / Lapsed | 1975-07-25 | 1977-08-09 | 43 | Details |
| US4020460A | Method and apparatus of checking to determine if a signal i… | Expired / Lapsed | 1975-11-13 | 1977-04-26 | 6 | Details |
| US4014005A | Configuration and control unit for a heterogeneous multi-sy… | Expired / Lapsed | 1976-01-05 | 1977-03-22 | 9 | Details |
| US4008460A | Circuit for implementing a modified LRU replacement algorit… | Expired / Lapsed | 1975-12-24 | 1977-02-15 | 18 | Details |
| US4007450A | Data sharing computer network | Expired / Lapsed | 1975-06-30 | 1977-02-08 | 16 | Details |
| US3961139A | Time division multiplexed loop communication system with dy… | Expired / Lapsed | 1975-05-14 | 1976-06-01 | 20 | Details |
| US3900836A | Interleaved memory control signal handling apparatus using … | Expired / Lapsed | 1973-11-30 | 1975-08-19 | 5 | Details |
| US3886525A | Shared data controlled by a plurality of users | Expired / Lapsed | 1973-06-29 | 1975-05-27 | 3 | Details |
| US3814917A | Signal processing device for weighting delta coded sequence… | Expired / Lapsed | 1973-05-29 | 1974-06-04 | 4 | Details |
| US3800078A | Digitally compensated scanning system | Expired / Lapsed | 1972-12-18 | 1974-03-26 | 12 | Details |
| US3771137A | Memory control in a multipurpose system utilizing a broadca… | Expired / Lapsed | 1971-09-10 | 1973-11-06 | 27 | Details |
| US3740723A | Integral hierarchical binary storage element | Expired / Lapsed | 1970-12-28 | 1973-06-19 | 4 | Details |
| US3736566A | Central processing unit with hardware controlled checkpoint… | Expired / Lapsed | 1971-08-18 | 1973-05-29 | 8 | Details |
| US3723971A | Serial loop communications system | Expired / Lapsed | 1971-12-14 | 1973-03-27 | 7 | Details |
| US3676860A | Interactive tie-breaking system | Expired / Lapsed | 1970-12-28 | 1972-07-11 | 12 | Details |
| US3673575A | Microprogrammed common control unit with double format cont… | Expired / Lapsed | 1970-06-29 | 1972-06-27 | 8 | Details |
| US3670307A | Interstorage transfer mechanism | Expired / Lapsed | 1969-12-23 | 1972-06-13 | 11 | Details |
| US3670309A | Storage control system | Expired / Lapsed | 1969-12-23 | 1972-06-13 | 33 | Details |
| US3643116A | Fast logic using ultrashort laser pulses | Expired / Lapsed | 1969-09-05 | 1972-02-15 | 29 | Details |
| US3639694A | Time division multiplex communications system | Expired / Lapsed | 1969-01-15 | 1972-02-01 | 18 | Details |
| US3634665A | System use of self-testing checking circuits | Expired / Lapsed | 1969-06-30 | 1972-01-11 | 10 | Details |
| US3633170A | Digital filter and threshold circuit | Expired / Lapsed | 1970-06-09 | 1972-01-04 | 13 | Details |
| US3623022A | Multiplexing system for interleaving operations of a proces… | Expired / Lapsed | 1969-12-29 | 1971-11-23 | 13 | Details |
| US3622767A | Adaptive control system and method | Expired / Lapsed | 1967-01-16 | 1971-11-23 | 14 | Details |
| US3611307A | Execution unit shared by plurality of arrays of virtual pro… | Expired / Lapsed | 1969-04-03 | 1971-10-05 | 13 | Details |
| US3593297A | Diagnostic system for trapping circuitry | Expired / Lapsed | 1970-02-12 | 1971-07-13 | 7 | Details |
| US3593300A | Arrangement for automatically selecting units for task exec… | Expired / Lapsed | 1967-11-13 | 1971-07-13 | 8 | Details |
| US3588839A | Hierarchical memory updating system | Expired / Lapsed | 1969-01-15 | 1971-06-28 | 0 | Details |
| US3585599A | Universal system service adapter | Expired / Lapsed | 1968-07-09 | 1971-06-15 | 41 | Details |
| US3573749A | Operator guidance and control termianl | Expired / Lapsed | 1969-03-28 | 1971-04-06 | 10 | Details |
| US3571733A | Adaptive delay line equalizer for waveforms with correlatio… | Expired / Lapsed | 1968-09-13 | 1971-03-23 | 8 | Details |
| US3566363A | Processor to processor communication in a multiprocessor co… | Expired / Lapsed | 1968-07-11 | 1971-02-23 | 0 | Details |
| US3564506A | Instruction retry byte counter | Expired / Lapsed | 1968-01-17 | 1971-02-16 | 0 | Details |
| US3560934A | Arrangement for effecting vector mode operation in multipro… | Expired / Lapsed | 1969-06-10 | 1971-02-02 | 0 | Details |
| US3551892A | Interaction in a multi-processing system utilizing central … | Expired / Lapsed | 1969-01-15 | 1970-12-29 | 0 | Details |
| US3550133A | Automatic channel apparatus | Expired / Lapsed | 1969-01-14 | 1970-12-22 | 0 | Details |
| US3544966A | Method and apparatus for multiplex control of a plurality o… | Expired / Lapsed | 1966-12-27 | 1970-12-01 | 0 | Details |
| US3543242A | Multiple level priority system | Expired / Lapsed | 1967-07-07 | 1970-11-24 | 0 | Details |
| US3541507A | Error checked selection circuit | Expired / Lapsed | 1967-12-06 | 1970-11-17 | 0 | Details |
| US3540000A | Criss-cross sorting method and means | Expired / Lapsed | 1967-11-02 | 1970-11-10 | 0 | Details |
| US3496551A | Task selection in a multi-processor computing system | Expired / Lapsed | 1967-07-13 | 1970-02-17 | 0 | Details |
| US3478325A | Delay line data transfer apparatus | Expired / Lapsed | 1967-01-16 | 1969-11-11 | 0 | Details |
| US3478321A | Variable priority storage accessing control | Expired / Lapsed | 1966-11-10 | 1969-11-11 | 0 | Details |
| US3466613A | Instruction buffering system | Expired / Lapsed | 1967-01-13 | 1969-09-09 | 0 | Details |
| US3434115A | Timed operation sequence controller | Expired / Lapsed | 1966-07-15 | 1969-03-18 | 0 | Details |
| US3432813A | Apparatus for control of a plurality of peripheral devices | Expired / Lapsed | 1966-04-19 | 1969-03-11 | 0 | Details |
| US3426332A | Data handling apparatus with recurrent address manipulation… | Expired / Lapsed | 1966-12-15 | 1969-02-04 | 0 | Details |
| US3411143A | Instruction address control by peripheral devices | Expired / Lapsed | 1966-01-13 | 1968-11-12 | 0 | Details |
| US3406633A | Collapsible chamber pump | Expired / Lapsed | 1966-11-07 | 1968-10-22 | 0 | Details |
| US3406366A | Electrical temperature sensor device | Expired / Lapsed | 1966-01-13 | 1968-10-15 | 0 | Details |
| US3399384A | Variable priority access system | Expired / Lapsed | 1965-09-10 | 1968-08-27 | 0 | Details |
| US3395391A | Data transmission system and devices | Expired / Lapsed | 1965-08-23 | 1968-07-30 | 0 | Details |
| US3387283A | Addressing system | Expired / Lapsed | 1966-02-07 | 1968-06-04 | 2 | Details |
| US3386082A | Configuration control in multiprocessors | Expired / Lapsed | 1965-06-02 | 1968-05-28 | 0 | Details |
| US3380030A | Apparatus for mating different word length memories | Expired / Lapsed | 1965-07-29 | 1968-04-23 | 0 | Details |
| US3377579A | Plural channel priority control | Expired / Lapsed | 1967-01-13 | 1968-04-09 | 0 | Details |
| US3374466A | Data processing system | Expired / Lapsed | 1965-05-10 | 1968-03-19 | 0 | Details |
| US3372378A | Input/output unit switch | Expired / Lapsed | 1964-04-27 | 1968-03-05 | 0 | Details |
| US3369990A | Cathodic sputtering apparatus including thermionic means fo… | Expired / Lapsed | 1964-12-31 | 1968-02-20 | 2 | Details |
| US3364467A | Cryogenic fault or error-detection and correction device ha… | Expired / Lapsed | 1959-12-30 | 1968-01-16 | 2 | Details |
| US3364468A | Cryogenic fault or error-detecting and correcting system ha… | Expired / Lapsed | 1959-12-30 | 1968-01-16 | 2 | Details |
| US3359543A | Data transmission system | Expired / Lapsed | 1965-07-02 | 1967-12-19 | 2 | Details |
| US3344406A | Sampled data reduction and storage system | Expired / Lapsed | 1964-11-09 | 1967-09-26 | 2 | Details |
| US3343141A | Bypassing of processor sequence controls for diagnostic tes… | Expired / Lapsed | 1964-12-23 | 1967-09-19 | 2 | Details |
| US3343135A | Compiling circuitry for a highly-parallel computing system | Expired / Lapsed | 1964-08-13 | 1967-09-19 | 2 | Details |
| US3333246A | Delay line clock | Expired / Lapsed | 1964-07-08 | 1967-07-25 | 2 | Details |
| US3333249A | Adaptive logic system with random selection, for conditioni… | Expired / Lapsed | 1964-06-29 | 1967-07-25 | 2 | Details |
| US3333248A | Self-adaptive systems | Expired / Lapsed | 1963-12-20 | 1967-07-25 | 2 | Details |
| US3328772A | Data queuing system with use of recirculating delay line | Expired / Lapsed | 1964-12-23 | 1967-06-27 | 2 | Details |
| US3327119A | Method and apparatus for detecting cancer cells | Expired / Lapsed | 1964-03-26 | 1967-06-20 | 2 | Details |
| US3323119A | Display system for a data processing unit | Expired / Lapsed | 1963-12-30 | 1967-05-30 | 2 | Details |
| US3315235A | Data processing system | Expired / Lapsed | 1964-08-04 | 1967-04-18 | 2 | Details |
| US3315233A | Self-addressing and self-assigning memory system | Expired / Lapsed | 1963-10-01 | 1967-04-18 | 2 | Details |
| US3311891A | Recirculating memory device with gated inputs | Expired / Lapsed | 1963-08-21 | 1967-03-28 | 2 | Details |
| US3310780A | Character assembly and distribution apparatus | Expired / Lapsed | 1962-10-15 | 1967-03-21 | 2 | Details |
| US3300763A | Message exchange system utilizing time multiplexing and a p… | Expired / Lapsed | 1963-08-20 | 1967-01-24 | 2 | Details |
| US3283124A | Selective heating apparatus | Expired / Lapsed | 1965-05-07 | 1966-11-01 | 2 | Details |
| US3280312A | System for measuring kiln conditions using thermocouples in… | Expired / Lapsed | 1962-12-11 | 1966-10-18 | 2 | Details |
| US3277447A | Electronic digital computers | Expired / Lapsed | 1964-03-18 | 1966-10-04 | 2 | Details |
| US3273131A | Queue reducing memory | Expired / Lapsed | 1963-12-31 | 1966-09-13 | 2 | Details |
| US3263216A | Pattern recognition error correction system employing varia… | Expired / Lapsed | 1964-03-20 | 1966-07-26 | 2 | Details |
| US3256516A | Data display centering and expansion system | Expired / Lapsed | 1962-06-20 | 1966-06-14 | 2 | Details |
| US3253263A | Code to voice inquiry system and twospeed multi-unit buffer… | Expired / Lapsed | 1961-04-10 | 1966-05-24 | 2 | Details |
| US3248705A | Automatic editor | Expired / Lapsed | 1961-06-30 | 1966-04-26 | 2 | Details |
| US3234524A | Push-down memory | Expired / Lapsed | 1962-05-28 | 1966-02-08 | 2 | Details |
| US3229259A | Multiple rate data system | Expired / Lapsed | 1962-02-01 | 1966-01-11 | 2 | Details |
| US3226683A | Sequential decision making device | Expired / Lapsed | 1960-10-19 | 1965-12-28 | 2 | Details |
| US3223925A | Digital data modulation device | Expired / Lapsed | 1962-01-29 | 1965-12-14 | 1 | Details |
| US3202969A | Electronic calculator | Expired / Lapsed | 1959-12-30 | 1965-08-24 | 1 | Details |
| US3191150A | Specimen identification system with adaptive and non-adapti… | Expired / Lapsed | 1962-10-30 | 1965-06-22 | 2 | Details |
| US3191149A | Specimen identification apparatus with means for altering s… | Expired / Lapsed | 1962-01-15 | 1965-06-22 | 2 | Details |
| US3166668A | Computer program system | Expired / Lapsed | 1960-03-24 | 1965-01-19 | 1 | Details |
| US3163848A | Double error correcting system | Expired / Lapsed | 1959-12-22 | 1964-12-29 | 2 | Details |
| US3153775A | Table look-up system | Expired / Lapsed | 1959-02-11 | 1964-10-20 | 2 | Details |
| US3150351A | Computer manual keyboard entry | Expired / Lapsed | 1957-09-10 | 1964-09-22 | 1 | Details |
| US3135946A | Error correction device | Expired / Lapsed | 1960-07-29 | 1964-06-02 | 2 | Details |
| US3130254A | Optical maser having terminal level above ground state | Expired / Lapsed | 1960-12-05 | 1964-04-21 | 2 | Details |
| US3103000A | Skew correction system | Expired / Lapsed | 1960-04-01 | 1963-09-03 | 2 | Details |
| US3100888A | Checking system | Expired / Lapsed | 1960-12-13 | 1963-08-13 | 0 | Details |
| US3098112A | Vapor cell light modulator | Expired / Lapsed | 1959-07-22 | 1963-07-16 | 2 | Details |
| US3085232A | Magnetic storage devices | Expired / Lapsed | 1958-10-03 | 1963-04-09 | 2 | Details |
| US3037700A | Indexing registers for calculators | Expired / Lapsed | 1956-11-29 | 1962-06-05 | 0 | Details |
| US3036773A | Indirect addressing in an electronic data processing machine | Expired / Lapsed | 1957-12-26 | 1962-05-29 | 0 | Details |
| US3022005A | System for comparing information items to determine similar… | Expired / Lapsed | 1959-01-12 | 1962-02-20 | 0 | Details |
| US3014659A | Electronic integrating means for continuous variable quanti… | Expired / Lapsed | 1953-11-27 | 1961-12-26 | 0 | Details |
| US3011133A | Oscillator utilizing avalanche breakdown of supercooled sem… | Expired / Lapsed | 1958-06-04 | 1961-11-28 | 0 | Details |
| US3001140A | Data transmission | Expired / Lapsed | 1957-11-29 | 1961-09-19 | 0 | Details |
| US2997692A | Binary comparator | Expired / Lapsed | 1959-01-30 | 1961-08-22 | 0 | Details |
| US2969912A | Error detecting and correcting circuits | Expired / Lapsed | 1957-02-26 | 1961-01-31 | 0 | Details |
| US2969522A | Data transmission and storage system | Expired / Lapsed | 1958-06-12 | 1961-01-24 | 0 | Details |
| US2968027A | Data processing system memory controls | Expired / Lapsed | 1958-08-29 | 1961-01-10 | 0 | Details |
| US2966664A | Magnetic core flip-flop | Expired / Lapsed | 1955-09-01 | 1960-12-27 | 0 | Details |
| US2957626A | High-speed electronic calculator | Expired / Lapsed | 1955-11-21 | 1960-10-25 | 0 | Details |
| US2942779A | Integrating device | Expired / Lapsed | 1952-09-30 | 1960-06-28 | 0 | Details |
| US2931022A | Spot sequential character generator | Expired / Lapsed | 1954-06-16 | 1960-03-29 | 0 | Details |
| US2921296A | Deskewing system | Expired / Lapsed | 1958-06-30 | 1960-01-12 | 0 | Details |
| US2919429A | Data transfer mechanism | Expired / Lapsed | 1954-10-25 | 1959-12-29 | 0 | Details |
| US2909972A | Display apparatus employing electro-optical devices | Expired / Lapsed | 1958-09-15 | 1959-10-27 | 0 | Details |
| US2910236A | Calculator program system | Expired / Lapsed | 1954-01-15 | 1959-10-27 | 0 | Details |
| US2907009A | Magnetic head commutator | Expired / Lapsed | 1956-07-05 | 1959-09-29 | 0 | Details |
| US2901166A | Digital computer | Expired / Lapsed | 1953-02-05 | 1959-08-25 | 0 | Details |
| US2846592A | Temperature compensated semiconductor devices | Expired / Lapsed | 1955-05-20 | 1958-08-05 | 0 | Details |
| US2814794A | Non-destructive sensing of magnetic cores | Expired / Lapsed | 1955-08-17 | 1957-11-26 | 0 | Details |
| US2798199A | Resistance testing machine | Expired / Lapsed | 1954-04-19 | 1957-07-02 | 0 | Details |
| US2792991A | Electronic commutator for calculators | Expired / Lapsed | 1953-11-23 | 1957-05-21 | 0 | Details |
| US2770797A | Data storage apparatus | Expired / Lapsed | 1951-12-31 | 1956-11-13 | 0 | Details |
| US2770725A | Binary-decade counter | Expired / Lapsed | 1951-12-21 | 1956-11-13 | 0 | Details |
| FR1119767A | Column shift device with counting | Expired / Lapsed | 1955-01-10 | 1956-06-25 | 0 | Details |
| US2703202A | Electronic binary algebraic accumulator | Expired / Lapsed | 1950-03-21 | 1955-03-01 | 0 | Details |
| US2700750A | Measuring and indicating system | Expired / Lapsed | 1952-04-25 | 1955-01-25 | 0 | Details |
| US2651204A | Automatic pressure measuring and indicating system | Expired / Lapsed | 1950-03-09 | 1953-09-08 | 0 | Details |
| US2636672A | Selective sequence electronic calculator | Expired / Lapsed | 1949-01-19 | 1953-04-28 | 0 | Details |
| US2616626A | Calculator | Expired / Lapsed | 1945-02-08 | 1952-11-04 | 0 | Details |
| US2604262A | Multiplying and dividing means | Expired / Lapsed | 1949-01-19 | 1952-07-22 | 0 | Details |
| US2594742A | Two source binary-decade counter | Expired / Lapsed | 1949-01-12 | 1952-04-29 | 0 | Details |
| US2536955A | Electronic accounting machine | Expired / Lapsed | 1944-12-27 | 1951-01-02 | 0 | Details |
| US2524154A | Electrical trigger | Expired / Lapsed | 1949-01-05 | 1950-10-03 | 0 | Details |
| US2484642A | Record card | Expired / Lapsed | 1945-12-17 | 1949-10-11 | 0 | Details |
| US2431058A | Control mechanism for dispensing apparatus | Expired / Lapsed | 1942-08-22 | 1947-11-18 | 0 | Details |
| US2405287A | Record controlled accounting machine | Expired / Lapsed | 1943-01-01 | 1946-08-06 | 0 | Details |
| US2369474A | Code translator | Expired / Lapsed | 1943-12-10 | 1945-02-13 | 0 | Details |
| US2353002A | Dispensing and tabulating machine | Expired / Lapsed | 1938-06-09 | 1944-07-04 | 0 | Details |
| US2344254A | Telemetering apparatus | Expired / Lapsed | 1943-01-27 | 1944-03-14 | 0 | Details |
| US2328611A | Dividing machine | Expired / Lapsed | 1942-04-18 | 1943-09-07 | 0 | Details |
| US2325958A | Printing mechanism | Expired / Lapsed | 1940-12-27 | 1943-08-03 | 0 | Details |
| US2323372A | Film data selecting and viewing machine | Expired / Lapsed | 1940-06-27 | 1943-07-06 | 0 | Details |
| US2318299A | Intercontrolled typewriter-punching machine | Expired / Lapsed | 1941-12-23 | 1943-05-04 | 0 | Details |
| US2314718A | Accounting apparatus | Expired / Lapsed | 1940-04-26 | 1943-03-23 | 0 | Details |
| US2310300A | Register mechanism for indicating instruments | Expired / Lapsed | 1940-08-02 | 1943-02-09 | 0 | Details |
| US2302002A | Record controlled perforating machine | Expired / Lapsed | 1941-11-29 | 1942-11-17 | 0 | Details |
| US2302009A | Transmission system for statistical data | Expired / Lapsed | 1939-03-25 | 1942-11-17 | 0 | Details |
| US2297789A | Transcribing apparatus | Expired / Lapsed | 1939-11-04 | 1942-10-06 | 0 | Details |
| US2294681A | Record card controlled machine | Expired / Lapsed | 1939-06-06 | 1942-09-01 | 0 | Details |
| US2288862A | Method of and means for preparing magnetizable bodies to re… | Expired / Lapsed | 1940-10-24 | 1942-07-07 | 0 | Details |
| US2282066A | Relay | Expired / Lapsed | 1939-09-08 | 1942-05-05 | 0 | Details |
| US2282029A | Recording device | Expired / Lapsed | 1939-06-30 | 1942-05-05 | 0 | Details |
| US2258110A | Accounting machine | Expired / Lapsed | 1938-08-31 | 1941-10-07 | 0 | Details |
| US2254933A | Record controlled machine | Expired / Lapsed | 1938-06-17 | 1941-09-02 | 0 | Details |
| US2244241A | Cross-adding accounting machine and programing means theref… | Expired / Lapsed | 1937-10-01 | 1941-06-03 | 0 | Details |
| US2244231A | Statistical record | Expired / Lapsed | 1936-12-17 | 1941-06-03 | 0 | Details |
| US2232006A | Accounting machine | Expired / Lapsed | 1937-12-30 | 1941-02-18 | 0 | Details |
| US2228330A | Calculating machine | Expired / Lapsed | 1937-06-09 | 1941-01-14 | 0 | Details |
| US2224774A | Tabulating machine | Expired / Lapsed | 1936-06-24 | 1940-12-10 | 0 | Details |
| US2217161A | Signaling system | Expired / Lapsed | 1939-01-14 | 1940-10-08 | 0 | Details |
| US2192612A | Multiplying machine | Expired / Lapsed | 1937-09-24 | 1940-03-05 | 0 | Details |
| US2166928A | Multiplying machine | Expired / Lapsed | 1934-05-10 | 1939-07-25 | 0 | Details |
| US2141598A | Automatic decimal point selecting device for accounting mac… | Expired / Lapsed | 1934-05-04 | 1938-12-27 | 0 | Details |
| US2131226A | Tabulating machine | Expired / Lapsed | 1934-06-07 | 1938-09-27 | 0 | Details |
| US2126666A | Multiplying machine | Expired / Lapsed | 1935-11-14 | 1938-08-09 | 0 | Details |
| US2124906A | Statistical machine | Expired / Lapsed | 1938-06-04 | 1938-07-26 | 0 | Details |
| US2111154A | Printing telegraph system | Expired / Lapsed | 1934-10-27 | 1938-03-15 | 0 | Details |
| US2062119A | Successive discount accounting machine | Expired / Lapsed | 1932-10-15 | 1936-11-24 | 0 | Details |
| US1972977A | Tabulating machine | Expired / Lapsed | 1929-07-18 | 1934-09-11 | 0 | Details |