Fatigue improvement nut
AssigneeKaynar Manufacturing Co., Inc.
InventorsErwin C. Witte, Paul V. Pagel
Life of this patent
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Abstract
The threads at the entrance end of a nut are interrupted by a plurality of circumferentially spaced axially extending flutes to form relatively flexible load distributing threads. The flutes extend axially across a limited number of threads and extend radially into the threads a distance short of the root of the thread. After engagement with a complimentary bolt, and upon the occurrence of a load on the connection, the interrupted threads flex axially of the nut to cushion shock on the bolt threads and shift the zone of maximum stress transfer axially inwardly of the nut, thereby materially extending fatigue life of the connection.
Claims5
In a fatigue improvement nut comprising a generally cylindrical nut body with a wrenching surface on the outer periphery and a threaded central bore for use with a conventional bolt, the improvement comprising a plurality of circumferentially spaced flutes in the threads of said nut extending axially from the bolt entrance end thereof across at least two threads and radially into the threads to approximately four-fifths of thread depth, thereby to weaken said threads sufficiently to allow axial flexure thereof relative to the uninterrupted threads of said nut when subjected axial loads thereby to move the zone of maximum stress transfer between said nut and said bolt from the interface between the engaged and non-engaged threads of said bolt to a zone located substantially centrally of the axial length of said nut.
Dependencies are inferred from the claim text.