Improvements in or relating to Nut LOCKS.
Year: 1898

page_text: Improvements in or relating to Nut LOCKS.
A communication from THOMAS MCNAIR RIGHTER, of the City of Mount Carmel,
County of Northumberland, State of Pennsylvania, United States of America,
Gentleman.
I, ALFRED JULIUS BOULT, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
The object of this invention is to produce a self locking nut which is cheap and
of simple and durable construction, and which will remain in any desired position
upon a bolt, without any tendency to become loose or to rattle. To these ends the
invention consists in a nut having a slit or kerf in its side, said kerf being
parallel or substantially parallel with the faces of the nut, and the portion above
the kerf being set inwardly, whereby the upper portion of the hole in the nut is
slightly flattened, one of its diameters being slightly longer and another slightly
shorter than the diameter of the bolt for which the nut is adapted. The set-in
portion of the nut is suitably proportioned so that it will yield as it is screwed upon
the bolt, but is heavy enough to grip the bolt with a strong spring pressure. The
invention is illustrated in the accompanying drawing in which
Fig. 1 is a top plan view of a nut constructed in accordance with the
invention.
Fig. 2 is a bottom plan view, and
Fig. 3 is a side view.
The drawing shows a hexagonal nut of the form customarily used upon rail
joints. It will be understood, however, that the invention is applicable to other
forms of nuts and to nuts which are adapted for other purposes.
In constructing this improved lock nut the cylindrical hole in the nut is punched
and threaded in the ordinary manner. A kerf a formed in the side of the nut,
substantially parallel to the upper and lower faces and preferably about one-third
way through the nut, as shown in the drawing, the dotted line a indicating the
inuer edge of the kerf or slit. The portion b above the kerf & is then subjected to
a blow or to pressure, in the direction of the arrow shown in Figs. 1 and 3, and
thus squeezed or set inwardly to a slight extent. This has the effect of reducing
the diameter in the direction of the arrow and increasing the diameter at right
angles to this direction, giving the upper part of the opening a slightly flattened
forin. This set should not be sufficient to prevent the upper part of the nut from
readily engaging the threads of the bolt, while at the same time it should be
sufficient to make the upper part of the nut grip the bolt quite forcibly. The
portion 6 need not bear any definite proportion to the full depth of the nut.
should be thin enough to enable the set-in portion to yield when the nut is screwed
on to a bolt, such portion then being partially restored to its original circular form.
The portion c below the kerf is not affected by the operation on the upper portion
and therefore the lower part of the hole remains perfectly round so that the nut can
It

page_text: be readily started upon the bolt. There is no distortion of the threads in the
direction of the axis of the nut and hence they always match perfectly with the
bolt threads.
Having now particularly described and ascertained the nature of this invention
as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is :-
'
A self locking nut, having a kerf in one side partially severing it on a plane sub-
stantially parallel with its upper and lower faces and having the portion above said
kerf set inward, the portion of the hole in the nut below the kerf being circular and
the portion above being reduced in one of its diameters, whereby the set-in portion
is adapted to grip the bolt, substantially as described.
Dated this 12th day of April 1898.
BOULT & WADE,
Agents for the Applicant.