Improvements in and Connected with the Manufacture of Lock-nuts.
Year: 1886

page_text: Date of Application, 2nd Oct., 1886.
Complete Left, 1st July, 1887.
Complete Accepted, 16th Aug., 1887.
PROVISIONAL SPECIFICATION.
Improvements in and Connected with the Manufacture of
Lock-nuts.
We, JAMES DUNBAR, of 9 Lena Gardens, West Kensington Park, in the County of
Middlesex, Engineer, and JOHN JAMES DAVIDGE CLEMINSON, of Villa Albano,
Norwood, in the County of Surrey, Engineer, do hereby declare the nature of this
invention to be as follows:-
:-
This invention relates to an improved method of manufacturing nuts intended to
grip and become locked upon the bolts, rods or other bodies, to which they are applied,
and thus to counteract the tendency such appliances otherwise have to shake loose and
slack back. The invention also relates to certain modifications which may, in some
instances, be advantageously effected in the formation of the bolts or other bodies to
which such nuts are intended to be applied.
Instead of stamping, forging or otherwise forming, a nut out of solid metal,
according to the method hitherto most commonly employed, we prepare the blank from
a bar of metal, preferably of rectangular section, coiled into a spiral form; the said
spiral being wound in such a manner that its successive convolutions lie close to one
another. The spiral rod is then sawn, or otherwise severed, into lengths corresponding
with, or somewhat greater than, the thickness the nuts are desired to assume. Each
blank so produced may then be heated, placed in a hexagonal, square or other shaped
die, and stamped for the purpose of imparting the requisite form to its outer periphery.
The size and form of its inner periphery may be preserved by inserting a mandril.
The operation of tapping having been carried out, the nut is ready for use.
Instead of coiling a rectangular bar into a spiral rod of sufficient length to form
several blanks, as above described, it will be obvious that a length of bar corresponding
with that required for each nut may be coiled separately. Under such circumstances,
we prefer to taper each end of the bar in such a manner that when coiled the product
resembles that resulting from the process of manufacture previously described.
The nut may comprise one, two, three or more, coils; but in any case, the normal
thickness of the coil in an axial direction is greater than the pitch of the screw-thread
with which the nut is to be tapped.

page_text: Bar's intended to be coiled for the purpose of this invention may be rolled or formed
with prominences at regular intervals; so that, when coiled and a blank produced
therefrom, the cross section of the latter corresponds with that desired for the nut.
The stamping operation before referred to may, in this case, be dispensed with.
In applying nuts constructed according to this invention to bolts or other bodies
upon which they are required to lock, the internal diameter of the nut and the
external diameter of the bolt are so related to one another that the former body fits
tightly upon the latter and necessitates the employment of some force in application.
This has the effect of slightly expanding the coils composing the nut, which are in
consequence forced asunder from one another, the result being that the several series
of threads appertaining to each coil of the nut become somewhat displaced in relation
to the threads formed on the bolt, a locking effect being thereby produced. Moreover,
any vibration communicated from the body against which such nut is applied is for
the greater part absorbed by the first or contiguous coil thereof.
The coils of the nut may be laid in either direction irrespectively of whether the
intended tapping be right-handed or left-handed.
According to one modification of this invention, a portion of the length of the nut
is composed of solid or continuous metal in transverse section, whilst the remainder is
composed of spiral metal. Or, the central section may be solid, whilst each extremity
of the nut is formed of coiled metal. We regard these variations, however, as less
advantageous; the provision for radial expansion being diminished, whilst the cost of
manufacture is increased.
To facilitate the employment of lock-nuts constructed as hereinbefore described and
intended to be expanded both radially and longitudinally during the process of
application, we sometimes make the bolts or other bodies with which such nuts are to
be used slightly taper; the diameter of the bolt at its outer extremity being such as
to enter the nut freely, and the expanding and locking process taking place gradually
as the nut is screwed upon the bolt. Or, the diameter of the bolt may gradually
increase and then gradually diminish towards that part where the nut is intended to
be located when in use. By this latter method, the largest diameter of the screwed
portion of the bolt is immediately behind the nut when in working position; additional
security against the nut slacking back being thereby afforded.
Dated this 29th day of September 1886.
G. G. M. HARDINGHAM,
191, Fleet Street, London, E.C.,
Agent for the Applicants.

page_text: Improvements in and Connected with the Manufacture of
Lock-nuts.
We, JAMES DUNBAR, of 9, Lena Gardens, West Kensington Park, in the County
of Middlesex, and JOHN JAMES DAVIDGE CLEMINSON, of Villa Albano, Norwood, in
the County of Surrey, Engineers, 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 :—
This invention relates to an improved method of manufacturing nuts intended to
grip and become locked upon the bolts, rods or other bodies, to which they are
applied, and thus to counteract the tendency such appliances otherwise have to shake
loose and slack back. The invention also relates to certain modifications which may
in some instances be advantageously effected in the formation of the bolts or other
bodies to which such nuts are intended to be applied.
the
Instead of stamping, forging or otherwise shaping, a nut out of solid metal
according to the methods hitherto most commonly employed, we prepare the blank
from a bar of metal, preferably of rectangular section, coiled into a spiral form ;
said spiral being wound in such a manner that its successive convolutions lie close to
one another. The spiral rod is then sawn, or otherwise severed into lengths corre-
sponding with, or somewhat greater than, the thickness the nuts are desired to assume.
Each blank so produced may then be heated, placed in a die of hexagonal, square or
other form, and stamped for the purpose of imparting to its outer periphery the requisite
shape. The size and form of its inner periphery may be preserved by inserting a
mandril. The operation of tapping having been carried out, the nut is ready for use.
And in order that our invention may be fully understood, we will proceed to describe
the same with the aid of the accompanying drawings; whereof Fig. represents
in side elevation a lock-nut manufactured according to our improved method and
before being applied to the bolt, the same nut after application to the bolt being
represented partly in elevation and partly in transverse section in Fig. 1. Sundry
variations of the invention are represented in Figs. 2 to 12.
In Figs. 1 and 1*, A is the nat, composed of coils a, and B is a bolt to which in the
present illustration the nut is applied. The internal diameter of the nut A before
application and the external diameter of the bolt B are so related to one another that
the former body fits tightly upon the latter and necessitates the employment of some

page_text: force in application. This has the effect of slightly expanding the coils a composing
the nut, which are in consequence forced asunder from one another, the result being
that the several series of threads appertaining to each coil of the nut become somewhat
displaced in relation to the threads formed on the bolt, a locking effect being thereby
produced. Moreover, any vibration communicated from the body against which such
a nut is applied is for the greater part absorbed by the first or contiguous coil. In
Figs. 2 and 3, the coils of the nuts are laid left-handed and right-handed respectively,
whilst the bolts and nuts are screwed and tapped with right-handed threads. In
Fig. 4 is represented a common type of fish-plate bolt provided with a square nut,
whereof the coils are laid to the left. In Fig. 5, the central portion a¹ of the nut is
folid, whilst the upper and lower portions are composed of coils a. In Fig. 6, the
lower portion a¹ of the nut is solid, and the remainder is composed of coils; whilst in
Fig. 7 the upper portion a¹ of the nut is solid, and the lower portion thereof is coiled.
In Fig. 8, a solid central portion al terminates in two coiled portions, the coils whereof
are laid in opposite directions. In Figs. 9 and 10, the coils whereof the nut is
composed are thicker; the nut illustrated in Fig. consisting of a single coil, and
that shewn in Fig. 10 of two coils or thereabouts. In conjunction with a nut of the
kind herein before described, a taper bolt may be employed, as shewn in Fig. 11. The
screw-threaded portion of the bolt is of the smallest diameter towards the part
coinciding with the bearing face of the nut, the taper being uniform.
To facilitate the employment of lock-nuts such as hereinbefore described with
reference to Figs. 1 to 4, and intended to be expanded both radially and longitudinally
during the process of application, we sometimes make the bolts or other bodies with
which such nuts are to be used slightly taper; the diameter of the bolt at its outer
extremity being such as to enter the nut freely, and the expanding and locking process
taking place gradually as the nut is screwed upon the bolt. Such a method of con-
struction is represented in Fig. 12, wherein the screwed portion of the bolt gradually
increases in diameter and then gradually diminishes towards that part where the nut
is intended to be located when in use. By this latter method, as also in the con-
struction described with reference to Fig. 11, the largest diameter of the screwed
portion of the bolt is immediately behind the nut when in working position; additional
security against the nut slacking back being thereby afforded.
The coils of the nut may be laid in either direction irrespectively of whether the
intended tapping be right-handed or left-handed. It will also be understood that the
nut may comprise one, two, three, or more coils.
In Figs. 1 to 12, the section lines have for the sake of distinctness been arranged
in opposite directions on adjacent coils, but this is not intended to indicate that each
coil is composed of a separate piece of metal.
Instead of coiling a rectangular bar into a spiral rod of sufficient length to form
several blanks, as hereinbefore described, it will be obvious that a length of bar
corresponding with that required for each nut may be coiled separately. Under such
circumstances, we prefer to taper each end of the bar in such a manner that when
coiled the product resembles that resulting from the process of manufacture previously
described.
Bars intended to be coiled for the purposes of this invention may be rolled or
formed with angular or other prominences at regular intervals; so that, when coiled
and a blank produced therefrom, the cross section of the latter corresponds with that
desired for the nut. The stamping operation before referred to may in this case be
dispensed with.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed, we claim :-
1. The improved lock-nut formed of or from a closely coiled bar of metal and
having an internal diameter slightly smaller than that of the bolt or other body to
which the nut is intended to be applied, the thickness of each coil in an axial direction
being greater than the pitch of the screw-thread employed.

page_text: 2. As a modification of the invention referred to in the preceding claiming clause,
the improved lock-nut formed partly of metal which is solid in a circumferential
direction and partly of metal consisting of a coil or coils, substantially as described
with reference to Figs. 5 to 8 of the accompanying drawings.
3. In the manufacture of spiral metal lock-nuts, forming one side of the bar with
angular or other prominences disposed at such intervals that when the bar is coiled
and cut into blanks, the latter correspond in shape with that required for the
finished nuts.
4. The combination, with a spiral metal lock-nut, of a doubly tapered bolt arranged
and operating substantially as described with reference to Fig. 12; the nut when in
working position having an enlarged portion of the bolt immediately beyond the outer
face of the former.