Patent assignee · US · COMPANY

HOFFCO Incorporated

33Patents
2Active
33Granted
37Portfolio score

Filing activity: May 27, 1975 → Mar 14, 2013 · 2 expiring within 5 years

Most-cited patents

PatentTitleAreaCited byStatus
US4188719A Lawn trimmer chain saw attachment Mechanical Engineering; Lighting; Heating 46 Expired
US6006434A Quick-release component connector for lawn tool Emerging Cross-Sectional Technologies 45 Expired
US4226021A Shaft assembly for lawn trimmer Emerging Cross-Sectional Technologies 44 Expired
US5647810A Drive arm-engaging roller for centrifugal clutch Mechanical Engineering; Lighting; Heating 35 Expired
US4035994A Lawn mower blade control apparatus Human Necessities 32 Expired
US5377774A Variable speed drive system Performing Operations; Transporting 31 Expired
US5597060A Centrifugal actuator for centrifugal clutch Mechanical Engineering; Lighting; Heating 29 Expired
USD252130S Power driven lawn trimmer General 27 Expired
US4148141A Lawn trimmer cutter head Human Necessities 27 Expired
US4102214A Variable-speed pulley and clutch Mechanical Engineering; Lighting; Heating 22 Expired
US4316355A Combined flywheel and clutch mechanism for lawn mower blade Human Necessities 21 Expired
US5437356A Centrifugal clutch Mechanical Engineering; Lighting; Heating 18 Expired
US4416107A Lawn mower blade control mechanism Human Necessities 18 Expired
US4126928A Method of making a shaft assembly Emerging Cross-Sectional Technologies 17 Expired
US5048616A Garden tiller tine assembly Human Necessities 17 Expired
US5411122A Cone ramp clutch Mechanical Engineering; Lighting; Heating 15 Expired
US4413468A Lawn mower blade retainer Human Necessities 14 Expired
US5246403A Pivoting belt tensioning device Mechanical Engineering; Lighting; Heating 13 Expired
US4148173A Lawn mower blade control apparatus Human Necessities 13 Expired
US4326368A Clutch and brake for rotary lawn mower Human Necessities 12 Expired
US4633978A Brake caliper includes mechanical actuator with camming device and manual wear compensator Emerging Cross-Sectional Technologies 12 Expired
US4335585A Lawn trimmer construction Mechanical Engineering; Lighting; Heating 12 Expired
US5427217A Steering clutch brake assembly Human Necessities 11 Expired
US4277936A Combined flywheel and clutch driver, and control and warning device Human Necessities 11 Expired
US6155940A Adjustable cam weights for torque converter Mechanical Engineering; Lighting; Heating 9 Expired

Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.