Park-Ohio Industries
52Patents
0Active
52Granted
35Portfolio score
Filing activity: Jun 24, 1974 → Oct 1, 1997
Most-cited patents
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US4475839A | Sucker rod fitting | Emerging Cross-Sectional Technologies | 47 | Expired |
| US4258241A | Slot furnace for inductively heating axially spaced areas of a workpiece | Electricity | 36 | Expired |
| US4370703A | Solid state frequency converter | Emerging Cross-Sectional Technologies | 36 | Expired |
| US4039794A | Apparatus and method for heating ferromagnetic abrasive shot | Electricity | 33 | Expired |
| US4122321A | Induction heating furnace | Electricity | 25 | Expired |
| US4438310A | Method and apparatus for inductively heating valve seat inserts | Emerging Cross-Sectional Technologies | 21 | Expired |
| US4251704A | Unit for induction heating and hardening gear teeth | Electricity | 21 | Expired |
| US4468549A | Induction heater arrangement for forging bar stock | Electricity | 20 | Expired |
| US4511956A | Power inverter using separate starting inverter | Electricity | 20 | Expired |
| US4420667A | Induction heating method and apparatus for elongated workpieces | Emerging Cross-Sectional Technologies | 17 | Expired |
| USD359406S | Table with removable tray and/or insert | General | 17 | Expired |
| US4114010A | Test circuit and method for matching an induction load to a solid state power supply | Electricity | 16 | Expired |
| US3935416A | Inductor-workpiece position detector | Chemistry; Metallurgy | 16 | Expired |
| US3944446A | Method of inductively heating and quench hardening camshafts | Emerging Cross-Sectional Technologies | 15 | Expired |
| US5564345A | Stackable table, table assembly, and tray and table combination | Human Necessities | 15 | Expired |
| US4537102A | Method of shearing metal billets | Emerging Cross-Sectional Technologies | 13 | Expired |
| US4418259A | Method and apparatus of uniform induction heating of an elongated workpiece | Emerging Cross-Sectional Technologies | 13 | Expired |
| US4401485A | Method for inductively heating thin-walled elongated workpieces | Emerging Cross-Sectional Technologies | 13 | Expired |
| US4385348A | Inverter with improved power factor control | Electricity | 11 | Expired |
| US4184798A | Workpiece rotating and feeding apparatus | Chemistry; Metallurgy | 10 | Expired |
| US4625090A | Apparatus for inductively heat treating workpiece bore walls | Emerging Cross-Sectional Technologies | 9 | Expired |
| US4401486A | Method for annealing work hardened portions of structural beams | Emerging Cross-Sectional Technologies | 9 | Expired |
| US4501942A | Method and apparatus for uniform induction heating of an elongated workpiece | Emerging Cross-Sectional Technologies | 9 | Expired |
| US4482793A | Apparatus for simultaneously heating a plurality of elongated workpieces | Emerging Cross-Sectional Technologies | 8 | Expired |
| US4317978A | Induction heater arrangement for forging bar stock | Electricity | 8 | Expired |
Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.