An Improved Method of Locking Nuts on. Bolts and Studs.
Year: 1892

page_text: Date of Application, 2nd Jan., 1892
Complete Specification Left, 31st Aug., 1892-Accepted, 15th Oct., 1892
PROVISIONAL SPECIFICATION.
An Improved Method of Locking Nuts on. Bolts and Studs.
WILLIAM PILE, No. 2, Maughan Street, Scotswood Road, Newcastle-on-Tyne,
Engineer, do hereby declare the nature of this invention to be as follows:-
An improved method of locking nuts on bolts and studs by the following means
of a saw-cut run half-way through the nut, the width of same to be about half the
pitch of threads on bolt, the distance being preferably one-third from the bottom,
but I do not confine myself to exactly these measurements. I also reduce the
bottom part of nut on the opposite side to saw-cut to the same depth as the width
of saw-cut or slot and extending past the centre of the nut at least one-sixteenth of
an inch. These measurements are proportionate in smaller or larger nuts.
The locking being effected by the closing up of the slot and the consequent
levelling up of the bottom faces.
My invention consists of special features in nuts for locking automatically on
bolts and studs where great vibration is present.
I first take an ordinary nut, and from the bottom of the nut, preferably about rd
of the whole depth of nut, I put a saw-cut of about one-sixteenth of an inch in
width, and not more than one-half of the pitch of threads on bolt or stud, and
starting, in a square nut from one of the four corners, and in a hexagon nut, from
one of the flat sides thus giving a greater section of metal at that part of the nut
where it is necessary. I extend the saw-cut to the other two corners or exactly half-
way through the nut. I then reduce the bottom of the nut, on the opposite side to
which the saw-cut is made, and starting at the opposite corner I extend the reduced
part in width, to preferably about one-sixteenth of an inch past the centre of the
nut, this takes it exactly the same distance past the bottom of the saw-cut, the
reduced part being equal in depth to the thickness of saw-cut itself.
When the nut is put on the bolt in its position for tightening up, the first part
to receive the weight is the bottom part on the same side as the saw-cut, this
canting the bolt until the other side of the nut, which is the reduced side, takes the
face of the nut & plate, the nut is now tightened up which brings the unequal
faces of the nut to an equal face, at the same time the saw-cut is closed up by the
pressure, giving the nut the appearance of a solid one. I extend the reduced part
on the bottom of the nut preferably about one-sixteenth of an inch past the centre
of the nut for the reason of allowing the thin portion of the nut, to bend or close
up to the other part.
I claim that this setting up or closing of the saw-cut, alters the thread on the
bolt inside the nut, extending only half-way round the bolt, which is caused by
allowing only the thickness of saw-cut to be half the pitch of threads, the nut taking
only one-half of a turn after the weight comes on. The nut now locked cannot be
disturbed by vibration nor slack back, but when great leverage is applied it will
screw off the bolt, righting the thread of the bolt again to its original angle and
pitch.
The bolt can thus be used several times, and when the nut is slacked off, it partly
opens the saw-cut, so that if the saw is again run down the old saw-cut and the
bottom reduced as before shown, then the same nut can be used over again.
Dated this 1st day January 1892.

page_text: COMPLETE SPECIFICATION.
An Improved Method of Locking Nuts on Bolts and Studs.
I, WILLIAM PILE of 2 Maughan Street, South Benwell, in the City and County
of Newcastle-on-Tyne, Marine Engineer do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention relates to an improved method of locking nuts on bolts and studs,
and in order to carry it into practical effect, firstly, I take an ordinary nut and at
or about one third the whole depth of nut measuring from the nut bottom I make a
saw cut of about one sixteenth of an inch in width for say a seven-eighths nut.
In a square nut the saw cut may start from one of the four corners and in a
hexagon nut from one of the flat sides, this giving a greater section of metal at that
part of the nut where it is necessary.
The saw cut may be carried to about the centre or about one sixteenth of an inch
past or beyond the centre of the nut.
I then reduce the metal of the nut bottom on the opposite side to that on which
the saw cut is made and I carry this reduced portion of the nut about one sixteenth
of an inch past or beyond the nut centre, the reduced portion or area being in
thickness equal to the thickness of the saw-cut itself.
When the nut is put on the bolt in its position for tightening up, the first part to
receive the weight is the bottom or raised part on the same side as the saw cut;
then by continuing the action of tightening up the effect is to cause the reduced
part of the underside of the nut to take its bearing against the washer or other plate
so as to bring the unequal faces of the underside of the nut to a more level face and
at the same time to close the saw cut.
This closing of the saw cut has the effect of altering a portion of the threads on
the bolt and nut so as to lock the nut quite securely in such manner that it cannot
be disturbed or slacked back from any ordinary vibration but when extra leverage
is applied it will screw off the bolt and then the saw cut will partly open and
rectify the threads to or approximating to their original angle and pitch.
I will more fully explain my invention with the aid of the accompanying drawings
in which
Figures 1, 2, and 3 show respectively a plan an elevation and a section of my
locknut and in the following description like letters of reference indicate like
parts.
+
Referring to the drawings, in the nut n, n¹ is the saw cut and n³ the reduced
portion of the bottom of the nut.
In Fig. 2 the nut is shown screwed down onto the bolt until the normal bottom
part of the nut just rests on the plate wo; now by continuing the screwing down of
the nut, the reduced part n³ of the nut is caused to take its bearing against the
plate w (see Fig. 3) while at the same time the saw cut is closed up and some of
the threads are altered for a portion of their circumferences so as to form a kind of
buttress thread as shown at n³. The nut is thus most securely locked.
In unscrewing the nut extra force is required to start it, the action of the
unscrewing partly reopening the saw cut and returning the threads to or approxi-
mating to their original angle and pitch, so that the nut can be again used.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that. what I
claim is :
1. The improved method of locking nuts on bolts and studs consisting in
forming in and on one side of the nut a saw cut and on the opposite bottom
surface of the nut a reduced or cut away portion of a thickness corresponding
to the thickness of the saw cut so that on tightening up the nut the saw cut

page_text: as to
may close to allow the previously uneven bottom of the nut to take a sufficiently
level bearing and at the same time alter the form of the threads 50
effectually lock the nut, the several parts being arranged and adapted to operate
substantially as herein described and illustrated in the drawings.
Dated this 30th day of August 1892.