Yield torque apparatus
Patent 4026369 Issued on May 31, 1977. Estimated Expiration Date: 
May 31, 1994. 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.
May 31, 1994. 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 3520215 3623557 3643501 3693726 3745820 InventorApplicationNo. 05/619656 filed on 10/06/1975US Classes:173/183, Proximity angle detector73/761, Threaded fastener stress73/779, Magnetic or inductive73/789, Stress-strain relationship determination73/847, Torsion73/862.23With detection of specific torque value or condition (e.g., peak torque)ExaminersPrimary: Purser, Ernest R.Assistant: Favreau, Richard E. Attorney, Agent or FirmInternational ClassB25B 23/14 (20060101)AbstractA wrenching apparatus for torquing a fastener to its yield point and automatically shutting off once the yield point is reached. The yield point is sensed by having the wrenching apparatus resiliently restrained and creating a pulse signal in response to an increment of restraint. Rotational output of the wrenching apparatus also creates a pulse for each increment of rotation chosen. The rotational pulses are counted and the restraint pulses are utilized to cancel the sum of the rotational pulses. The yield point is detected when the sum of the rotational pulses exceeds a predetermined number without having received a restraint pulse cancellation. The count system is activated only after a predetermined level of total restraint is achieved thereby assuring the fastener is seated and the fastener tension is increasing in its linear range. | |
