An Improved Nut Lock
Year: 1891

page_text: Date of Application, 1st Dec., 1891-Accepted, 9th Jan., 1892
An Improved Nut Lock,
I, HENRY BERNOULLI BARLOW, of 17 St. Ann's Square, Manchester, in the
County of Lancaster, M.I. Mech. E. and Patent Agent, do hereby declare the
nature of this invention, which has been communicated to me from abroad by
Joseph A Harris of 228 Main Street, Moncton N.B. Canada, Barrister, 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 improvement in nut fastenings on bolts or in nut locks
and nuts used in connection with bolt and nut fastenings, by means of which screw
nuts may be permanently secured and held so firmly in position as not to be moved or
worked loose by any action of machinery, their own action, or by any jars or
vibration whatever--the functions being friction obtained by a flexible spring
resistance and a yielding of the parts held together-this being especially desirable
where machinery is subjected to jars, which, were there no yielding lock, might
rupture the threads and loosen the nut on the bolt, while at the same time the
device may be used in some cases as a combined nut and nut lock in one piece, the
friction being greatly increased as the nut lock is moved or set against the nut,
whereby safety, economy and neatness of finish are secured.
It consists in the combination with a bolt and a primary nut, of a flat locking
plate or washer of suitable thickness or flexibility to constitute or form a spring
plate, (or said plate may be formed slightly concaved on its inner or under side),
and, provided with a thread cut at a suitable angle or bevel according to the size of
the bolts and nuts used, so that said locking plate will move along the bolt in an
oblique position. As the locking plate or washer approaches the primary nut, it
operates to fasten the nut, and the latter reacts to hold the plate in place; and a
tight bearing or contact first takes place on the side of the plate that first contacts
with the nut, while the other side will show no bearing, but as the locking plate is
screwed home by means of a suitable implement, the elasticity or flexibility of the
plate causes it to yield or give, to permit the locking plate being screwed up far
enough to bear flat against the nut and close the space between the nut and said
plate, whereby the frictional contact of the locking plate with the nut, and the
tension or force of the deflected elastic plate holds the nut so tightly that it cannot
be loosened under any circumstances except the unscrewing of the locking plate by
suitable appliances.
I have ascertained by experiments that the thread of the nut lock should be cut
at an angle of from two to five degrees from the square, and it is better that it do
not contain more than from one and a half to three threads the said angles and
threads to be made to correspond with the sized nut that is required for use;
on large nuts the angle should be less and the thread greater in length, while in
small nut locks the angle may be increased and the thread shortened. It is the
angle or incline of the thread cut in the nut lock causing the oblique position of the
same on the bolt, together with the flexible, elastic locking plate or washer adapted
to be bent or deflected from its oblique position by frictional contact with the
primary nut as said plate or washer is screwed home, as herein before described,
that constitutes the value of my invention, as well as the compound pressure that is
exerted or brought to bear upon the parts.
1
In the drawings similar letters will represent similar parts in the several figures.
Figure 1, represents a top view of the nut lock A.
Figure 2 is a vertical section thereof showing the position or angle, or bevel of
1 D

page_text: Figure 3, is a vertical section of the nut D, showing thread, in comparison WILD
the thread on the nut lock A.
Figure 4, represents a view of the bolt E, and nut D upon which nut lock A is to
operate, and shows the position of nut lock A, before being tightened, or set against
the nut D, the dotted lines representing the position of the plate or washer when
screwed home from its initial position.
Figure 5 shows the locking plate or washer with its inner or under side slightly
concaved to increase the binding pressure of the threads.
To show the working of this invention, take the nut-lock A, and place it on
thread of bolt E and move it up until one part of it touches nut D. In placing it
thus towards the face of the nut, it will, before being tightened, be on an angle or
incline from nut D, owing to the bevel of thread 13 that is cut in nut lock A., and a
space will appear on the opposite side as shown at .J.
The locking plate or washer is made of a flat piece of steel, of suitable thickness
and properly tempered to make said plate somewhat elastic or flexible so that under
considerable strain or pressure, as when the plate or washer is screwed tight against
the primary nut, said plate will yield or give sufficiently to enable it to be forced
tightly against the nut.
The cutting process in manufacture will generally give the plate a slight con-
cavity and increase its binding pressure on the threads. In tightening nut-lock A
against nut D a compound friction is produced, differing from the friction in
ordinary cases by reason of the oblique position of nut-lock A upon the bolt, and
the flexibility or yielding quality of the plate or washer A; thread B and thread I,
coming in contact at an angle, as before mentioned, will operate and bind strongly
against each other, the threads having an inclination to cross, and as the pressure
is exerted upon the nut-lock A, the binding will be upon the nut D at its first point
of contact with the nut-lock, and be gradually increased as the opposite side of the
nut lock A, moves towards and comes in contact with nut D until the whole face of
the nut-lock bears tightly against the nut. When thus firmly set, a solid and
complete fastening is obtained, inasmuch as the two cannot be moved at once, or
together in any direction without rupturing or distorting the threads on bolt E,
and the friction of the two threads B and I, having an inclination to cross cach
other, but yet relieved by the flexibility of the plate, combined with the increasing
pressure on the bearing side thereof, and the pressure of the whole nut-lock itself
when set against the primary nut, causes it to be held permanently fixed, yet not
too rigid, upon the bolt, as the nut-lock A is held in position to prevent any back-
ward or forward movement of the nut.
I may also add that the locking washer may always be removed without causing
any injury to the thread on the bolt. I do not confine myself to the precise form
of the parts shown, as some variations may be made without materially departing
from the scope and object of my invention.
Having now particularly described & ascertained the nature of this said inven-
tion & in what manner the same is to be performed" I "declare that what I
claim is
17.
1. The combination with a bolt, and primary nut, of the spring metal elastic
washer or locking plate, having an oblique thread cut diagonally therein to its faces
and screwed on to the bolt exteriorly of the primary nut, said "elastic washer when
screwed down, being deflected or bent from its initial diagonal position on the bolt
by contact with the nut, and bearing against said nut with increased force or com-
pound frictional contact, in the manner and for the
herein described.
purpose
2: In a nut-lock, the combination with a bolt and a primary nut, of the inclined
locking plate or washer arranged on the bolt exteriorly of the nut thereon; and
liaving the oblique threads cut at an angle to its faces said flat locking plate lying
at an angle to the face of the nut, and being of suitable thickness and temper in
proportion to the nut and bolt, to spring or yield as the contact between the faces of
the nut and plate are increased, whereby the locking plate is bent or deflected as.it,
T

page_text: is screwed home, and a compound frictional contact is secured between said plate
and nut without deflecting the end of the bolt, as set forth.
3. As an article of manufacture the elastic metal plate or washer herein
described, having a thread diagonal to its bearing to engage the bolt on an incline
in order to produce torsional spring resistance, and a yielding of the parts held
together, to secure the nut, and operate substantially as herein set forth.
4. In a nut-lock, the combination with a bolt and a primary nut, of the concaved
locking plate or washer arranged on the bolt exteriorly of a primary nut thereon
with its concaved side toward said primary nut, and having the oblique threads cut
at an angle to engage the bolt on an incline, said concaved locking plate or washer
when set against said primary nut, being deflected from its initial diagonal position
by frictional contact with said nut and bolt, and slightly spreading at its base.
bearing against said primary nut with increased compound frictional contact,
whereby the threads therein are compressed to lock said nut, and cause torsional
spring resistance, and a yielding of the parts held together, thereby effectually
preventing any backward or forward movement of the nut on the bolt, as herein
set forth.
Dated this 30th dor of November 1201
H. B. BARLOW,
17, St. Ann's Square, Manchester.