Rotary electric tool
Patent 4898249 Issued on February 6, 1990. Estimated Expiration Date: 
July 5, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 5, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2936662 3187860 3610343 3739659 3845673 Device for tightening bolts Torque responsive speed shift mechanism for power tool Electric tool, particularly a handtool, with torque control Electrically-operated driver Patent #: 4617843 InventorAssigneeApplicationNo. 215553 filed on 07/05/1988US Classes:173/176, Drive means responsive to torque or speed condition81/469, Means for regulating motor81/473, Rotatable, coaxial, clutching components173/217, Electric motor475/153, With condition responsive control475/263, Overload release475/266, Stepped, torque responsive ratio change475/299Orbit shiftable relative to sun and carrierExaminersPrimary: Yost, Frank T.Assistant: Smith, Scott A. Attorney, Agent or FirmForeign Patent References
International ClassesB23Q 005/12B25B 023/151 Foreign Application Priority Data1987-08-05 JPAbstractA rotary electric tool in which a differential gear mechanism is mounted within a gear case fixed to a housing for example; projections are formed on the outer peripheral surface of an internal gear of a final planetary gear mechanism in the differential gear mechanism, the said projections being brought into engagement with a projection-formed surface of a torque adjusting cam; the internal gear and the torque adjusting cam can be changed in relative position axially by reaction force of the internal gear; and the rotation of an output shaft is changed over between high and low speed conditions according to an axial displacement of the internal gear. | |
