Programmable pulsed torque recovery system
First Claim
1. In an electric nutrunner joint fastening system including one or more electric nutrunners having a motor and gearing, the improvement comprising:
- a pulse torque nutrunner control circuit providing for one or more torque pulses at the end of each fastener tightening cycle to recover torque loss due to joint relaxation while maintaining said nutrunner motor under load so as to avoid excessive gear wear.
3 Assignments
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Accused Products
Abstract
A method and apparatus for recovering torque lost due to joint relaxation in threaded fastener assemblies or joints. The present invention is especially adapted for use with medium-to-short or gasketed joints. In the practice of an exemplary embodiment of the invention, the torque of an electric nutrunner is pulsed at the end of a fastener tightening cycle between programmed maximum and minimum torque values which have been selected to overcome the static to dynamic torque ratio of the joint while maintaining the motor and gearing of the nutrunner in a loaded condition to ensure maximum nutrunner durability.
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Citations
10 Claims
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1. In an electric nutrunner joint fastening system including one or more electric nutrunners having a motor and gearing, the improvement comprising:
a pulse torque nutrunner control circuit providing for one or more torque pulses at the end of each fastener tightening cycle to recover torque loss due to joint relaxation while maintaining said nutrunner motor under load so as to avoid excessive gear wear. - View Dependent Claims (2, 3, 4)
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5. In a method of tightening one or more threaded fastener joint assemblies using an electric nutrunner system including at least one electric nutrunner having a motor and gearing and a programmable motor control circuit, the improvement comprising the steps of:
providing one or more torque pulses at the end of a fastener tightening cycle to correct for joint relaxation while maintaining the nutrunner motor under a positive load to reduce motor and gear wear. - View Dependent Claims (6, 7, 8, 9, 10)
Specification