Screw driver
Patent 3934629 Issued on January 27, 1976. Estimated Expiration Date: 
January 27, 1993. 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.
January 27, 1993. 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 2790471 2886075 3146811 3174599 InventorAssigneeApplicationNo. 05/535684 filed on 12/23/1974US Classes:81/429Responsive to movement of workExaminersPrimary: Smith, Al LawrenceAssistant: Smith, Gary L. Attorney, Agent or FirmInternational ClassesB25B 23/14 (20060101)B25B 23/145 (20060101) Foreign Application Priority Data1974-01-15 SWAbstractA screw driver comprising a torque responsive clutch for determining the final tightening torque and an output spindle connected to a forwardly extending screw bit. The spindle is axially displaceable from a forward rest position to an intermediate tightening position and a rear position in which dogs on the spindle engage dogs on the driving part of the clutch for inactivation of the clutch. The spindle, which is spring-biased toward its normal tightening and rest positions, is permitted to reoccupy its normal tightening position during the final tightening sequence in that a stud element on the screw driver housing is arranged to abut against the screw landing surface, thereby automatically preventing the screw driver housing and the clutch from following the spindle and screw bit to their final positions and ensuring reactivation of the clutch. | |
