Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Internally threaded fastener element – e.g. – nut – etc. – Multipart
Utility Patent
1999-06-23
2001-01-02
Wilson, Neill (Department: 3627)
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Internally threaded fastener element, e.g., nut, etc.
Multipart
C411S324000, C411S437000, C411S937100
Utility Patent
active
06168361
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to fasteners, and more specifically to locknuts.
A limitation of most prior art locknuts is their limited reusability. That is, they can only be removed and re-installed a limited number of times. Indeed, as little as one re-use will substantially reduce their gripping torque. This is the case for locknuts with various types of deformed threads and with plastic inserts.
Other limitations of prior art locknuts include excess axial length and weight (compared to conventional nuts) and a substantial loss of gripping force when installed without protruding threads. This latter limitation is due to the fact that most screws and bolts have a few smaller diameter threads at their ends and prior art locknuts grip only at their axially outer portion.
As a matter of nomenclature, it is common to characterize a nut by its mean pitch diameter, which is defined by points halfway between the thread's minimum and maximum radial extents (i.e., halfway between the peak and the valley).
SUMMARY OF THE INVENTION
The Present Invention provides a locknut which offers several significant improvements over the prior art. Embodiments of the invention have high degree of reusability, can be made the same axial length and weight as conventional nuts, grip well even without protruding threads, can have the amount of grip easily adjusted by the user, and are less expensive than most prior art locknuts.
In short, a locknut according to the invention comprises a C-shaped nut with a radial gap cut through one side. It is useful to define the term “reference diameter” as the mean pitch diameter of a normal nut designed for use with the externally threaded element with which the locknut is intended to be used.
The locknut functionality is provided by one or more of the following features. In one set of embodiments, the threads of the nut are undersize relative to the reference diameter (i.e., have a mean pitch diameter less than the reference diameter). In another set of embodiments, the C-shape is deformed inward such that the internal threads are out of round until the nut is assembled on a screw. Upon assembly the radial gap permits the nut to expand to fit the screw while the resulting radial spring tension grips the screw. In another set of embodiments, the nut is twisted, axially displacing the threads on opposite sides of the gap. Upon assembly the nut assumes an untwisted shape and the resulting axial spring tension grips the screw.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.
REFERENCES:
patent: 516285 (1894-03-01), Vaughan
patent: 696998 (1902-04-01), McLean
patent: 961063 (1910-06-01), Austin
patent: 1013521 (1912-01-01), Swenson
patent: 1181248 (1916-05-01), Posson
patent: 1375781 (1921-04-01), De Long
patent: 1394730 (1921-10-01), Hayter et al.
patent: 1722783 (1929-07-01), Basseches
patent: 2172461 (1939-09-01), Whitescarver
patent: 2386296 (1945-10-01), De Fazi
patent: 2490728 (1949-12-01), Cox
patent: 2797606 (1957-07-01), Poupitch
patent: 2901938 (1959-09-01), Van Buren, Jr.
patent: 2931264 (1960-04-01), Dallman
patent: 2932898 (1960-04-01), Enders
patent: 3052130 (1962-09-01), Kellogg et al.
patent: 3501828 (1970-03-01), Schultz
patent: 5074731 (1991-12-01), Schneider
patent: 681489 (1930-02-01), None
patent: 291426 (1928-02-01), None
patent: 349594 (1931-06-01), None
patent: 471517 (1952-05-01), None
Townsend and Townsend / and Crew LLP
Wilson Neill
LandOfFree
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