Thread cleaning nut

A thread cleaning nut including a nut body having a central axis, first and second spaced apart faces formed on the nut body and a central aperture extending through the nut body along a central axis between the first and second faces. A screw thread is formed between the first and second faces within the central aperture wherein less than one-half of the first face is shaped as a first flat surface and more than one-half of the first face is shaped as a second flat surface inclined at an actue angle to the first flat surface. An end portion of the screw thread between the first and second surfaces is exposed to define at least one cutting tooth for cutting a path for the screw thread. The first and second surfaces intersect a third flat surface. The third flat surface intersects the central aperture at a position spaced from the central axis and it intersects the end portion of the screw thread at an acute angle to define a cutting edge of the at least one cutting tooth. Preferably, the first and third surfaces are formed by a single path, straight-line milling operation. Also, preferably, both faces of the nut body are so machined on opposite sides of the central axis.

TECHNICAL FIELD 
This invention relates to thread cleaning nuts and, in particular, to 
thread cleaning nuts which are relatively easy to form from conventional 
nuts. 
BACKGROUND ART 
There are a wide variety of self-cleaning threaded nuts in which the top 
and bottom faces of the nut have been machined to form an interruption of 
the threads which allows the nut to clean adjacent threads while turning 
in either direction. 
For example, the U.S. Patent to Pease No. 2,091,274 discloses a thread 
cleaning nut in which the top and bottom faces of the nut have been 
machined to form an interruption of the threads which provides for 
cleaning of adjacent threads. 
The U.S. Patents to Crawford No. 3,896,495, Lanius, Jr., 3,501,995, and 
Paquette 561,913 are further examples of nuts having thread cleaning 
features. 
Other U.S. patents of a more general interest are the U.S. Patents to 
Schrader No. 1,347,124, Thomas, No. 1,447,578 and Gutensohn No. 2,562,032. 
One of the problems with conventional thread cleaning nuts is the number of 
machine cuts required to produce the thread cutting feature. For example, 
in the above-noted Pease patent, at least three machine cuts are required, 
12 if both faces of the nut are included. 
The nut of the Paquette patent requires three straight cuts and three 
curved cuts. The relatively large number of machine cuts typically makes 
the product impractical to mass-produce. 
Another problem with the prior art is that the end face of the machined nut 
has a relatively small percentage still intact and what is left is not 
continuous so that the thread cleaning features may be crushed if the 
threads are over tightened. 
One way to overcome this problem is to make the nut from a harder steel. 
However, this increases production costs even more. A larger face is 
desirable since it increases the chance of the nut staying tight in 
constant pressure motion areas, such as on an engine of an automobile or 
on heavy equipment. 
Another problem generally associated with the prior art is that so many of 
the designs are not practical and, thus, a relatively hard material must 
be used for the nut. For example, without harder material, the thread 
cutting mechanisms of many such designs have a tendecy of breaking off or 
may get jammed on a dirty or rusty bolt. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a thread cleaning nut 
which is relatively easy to produce. 
Another object of the present invention is to provide a thread cleaning nut 
which can be easily produced in a simple machining operation. 
Yet, still another object of the present invention is to provide a thread 
cleaning nut which can be produced in a single-pass, straight-line milling 
operation. 
Yet, still further another object of the present invention is to provide a 
thread cleaning nut which is relatively easy to produce and yet still 
retains over 50% of its end face to not only protect its cleaning internal 
thread, but also to insure that the nut stays tightly secured. 
In carrying out the above objects and other objects of the present 
invention, a thread cleaning nut is provided including a nut body having a 
central axis, first and second spaced apart faces formed on the nut body 
and a central aperture extending through the nut body along the central 
axis between the first and second faces. A screw thread is formed between 
the first and second faces within the central aperture. Less than one-half 
of the first face is shaped as a first flat surface and more than one-half 
of the first face is shaped as a second flat surface inclined at an acute 
angle to the first flat surface. An end portion of the screw thread 
between the first and second surfaces is exposed to define at least one 
cutting tooth for cutting a path for the screw thread. 
Preferably, each of the first and second faces are machined on opposite 
sides of the central axis by a single-pass, straight-line milling 
operation. 
The advantages accruing to such a thread cleaning nut are numerous. For 
example, the nut need not be specially hardened, but may be formed from a 
low to medium carbon steel. Also, a relatively large surface area of the 
face of the thread cleaning nut still remains intact after the milling 
operation to ensure that not only the cleaning features of thread remain 
intact, but also more than 50% of the face of the nut is still useful to 
secure the nut. 
The advantages of the present invention will be readily appreciated as the 
same because better understood by the following detailed description when 
considered with the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring now to the drawing figures, there is illustrated in FIG. 1, a 
thread cleaning nut constructed in accordance with the present invention, 
generally indicated at reference numeral 10. The thread cleaning nut 10 is 
illustrated threaded on a bolt, generally indicated at 12. As will be 
described in greater detail hereinbelow, the nut 10 is adapted to clean a 
thread of the bolt 12 or other threaded fasteners such as a screw. 
The nut 10 includes a nut body 14, having a central axis 16. The nut 10 
also includes first and second spaced apart faces 18 formed on the nut 
body 14. A central aperture 20 extends through the nut body 14 along the 
central axis 16 between the first and second faces 18. A screw thread, 
generally indicated at 22, is formed between the first and second faces 18 
within the central aperture 20. 
As best shown in FIG. 2, less than one-half of the first face 18 is shaped 
as a first flat surface 24 and more than one-half of the first face 18 is 
shaped as a second flat surface 26 which is inclined at an acute angle to 
the first flat surface as is best shown in FIG. 3. 
As best shown in FIG. 3, an end portion 28 of the screw thread 22 between 
the first and second surfaces 24 and 26, respectively, defines at least 
one cutting tooth and, preferably, two cutting teeth for cutting a path 
for the screw thread 22. 
The first and second surfaces 24 and 26, respectively, also intersect a 
third flat surface 30. The third flat surface 30 intersects the central 
aperture 20 at a position spaced from the central axis 16 and further 
intersects the end portion 28 of the screw thread 22 at an acute angle to 
define cutting edges on the cutting teeth. 
Referring now to FIG. 4, there is illustrated a milling tool 32 wherein 
both the first and third surfaces 24 and 30 are formed by a single pass, 
straight-line milling operation with the nut 10 held at an inclined 
position. As can be seen from the drawing figures, the third flat surface 
30 with respect to the second flat surface 26 as a result of the inclined 
position of the nut 10 during the milling operation. 
Preferably, the nut is made from a low to medium carbon steel and there is 
no need to form the nut 10 from an extra strong metal. 
Referring now to FIG. 5, there is illustrated the thread cleaning nut 10 
having both of its end faces 18 formed with the thread cleaning features 
on opposite sides of the central axis 16 so that the nut 10 can clean 
bolts, such as the bolt 12, during both threading and unthreading 
operations. In other words, the cutting edges of the cutting teeth clean 
the thread of the bolt during threading operation and during unthreading 
operation. 
The advantages accruing to the invention as described above are numerous. 
For example, the nut 10 is relatively easy to machine and the nut 10 need 
not be formed from extra strong steels. The nut 10 also protects the 
thread cleaning features from collapse during use while still retaining a 
sufficient amount of the first and second faces 18 as bearing surfaces 
against a part to be secured by the nut 10. 
While the best mode for carrying out the invention has herein been 
described in detail, those familiar with the art to which this invention 
relates will recognize various alternative designs and embodiments for 
practicing the present invention as defined by the following claims.