Improvements in Nut-locks.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Nut-locks.
I, JOHN WILLIAM BARTER COOK, of Camden, Arkansas, United States of
America, 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, and accompanying drawing, that is to say :-
My invention relates to devices for preventing a nut from unscrewing from a
bolt when the said bolt and nut are subjected to frequent jarring or other strains
tending to shake the nut loose; and the said invention is designed to provide a
mut-lock which can be cheaply and easily applied, and which will securely hold the
nut against unscrewing.
With many of the forms of nut-locks now in use the elasticity of a spring has to
be overcome in screwing up greatly increasing friction, while in unscrewing the
said spring bites into the nut, making it difficult to remove the nut for any purpose.
In many other forms of nut-locks the device is either complex in use or expensive
in manufacture.
The parts combining together to perform the functions of my invention are a
polygonal nut, preferably rectangular, a washer held against turning and having a
plurality of symmetrically disposed holes adapted to receive either arm of a key
having two reverse symmetrical arms, each attached to a vertical stem and equal in
height to the thickness of the washer and adapted to be covered by the angles of
the said nut. The number of said holes should be greater or less than, but not
equal to the number of sides of the said nut. The number of said holes should
preferably be either one more than or one less than the number of sides of the nut,
in order that a vernier effect may be obtained; or, in other words, in order that
the washer may be weakened by only the fewest number of holes possible with, at
the same time the greatest difference in the angular distance of each hole from the
angle of the nut next in front of it, it being desirable that the nut should be turned
back through the shortest possible distance and at the same time that the arm of
the reversible key set in the washer be sufficiently covered by the nut to prevent
the said key from falling out.
My nut-lock is an exceedingly cheap and convenient device, and has worked well
in practice.
While the said nut-lock is applicable in all cases where screw-bolts are subjected
to jarring strains, I shall describe it as applied to making the joints of rails.
Reference is had to the accompanying drawings, wherein-
Figure 1 is a vertical projection of a portion of a rail and fish-plate, showing my
device.
Fig. 2 is a vertical section along the line of Fig. 1.
Fig. 3 is a perspective view of my locking-key.
A represents the nut; B, the bolt; C, a flat ring-washer having rectangular
holes D with semi-cylindrical ends. While I have shown five of these holes, any

page_text: E represents the key, symmetrical in shape, the two arms e and e', being
reversible and the faces e and e' and e³ and e', exactly alike. The depth of each
arm of the key is just equal to the thickness of the washer.
F and F represent two pins passing through holes c in the washer C and
penetrating the washer-plate H. The function of these two pins and the washer-
plate is to keep the washer from turning; but an angular washer may be used on
railroads adapted to fit snugly between the upper and lower flanges of the rails,
and thus the washer-plate may be done away with. Moreover, when the washer
goes over wooden timbers spikes may be used to hold the washer against turning,
and the washer-plate may be dispensed with. K and K' represent the fish-plates
and R the rail.
The operation of my device is as follows:
After the bolt is in place, put on the washer-plate and secure the washer thereto
by the pins F F. Then screw down on the nut, and when it is home insert the
key in the nearest hole to a backing corner of the nut and turn the nut back over
At any
the arm of the key sunk in the washer. This locks both the nut and key.
time if the nut becomes loose from wear, screw up the nut and insert the key in the
hole nearest to a backing corner of the nut, as before. It will be noted that by
having the two arms and e' of the key E at right angles to the stem, and
symmetrical, the lower face e' of the upper arm bears against the upper surface of
the washer, and since the upper face e of the lower arm bears against the bottom of
the put it will be impossible to bend the said stem outward without breaking it, or
to round the edge of the hole in the washer, while at the same time the key will be
firmly set with a very little back-pressure. Moreover, by having the two arms
symmetrical and reversible no time will be lost in adjusting the key, and since
there are two available arms flaws due to the manufacture or wear of the keys will
not be so important as if there were only one arm and any great nicety of fit
required. By having a plurality of holes differing in number from the sides of the
nut I get a vernier effect, and always have one hole close to an angle of the nut. This
would not be the case were I to have one hole or a number of holes symmetrically
arranged, equal to the number of sides of the nut.
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 herein described nut-lock consisting of a washer held against turning and
a key having an arm fitting partly in said washer and projecting therefrom, with a
nut adapted to turn backwards slightly, covering a portion of the key fitting in the
said washer and bringing up against a portion of the said key protruding therefrom,
substantially as described.
2. In a nut-lock, the combination, with a polygonal nut, of a washer held against
turning, a hole or holes in said washer, and a key having two reverse symmetrical
arms, each attached to a vertical stem, and equal in height to the thickness of the
washer, one arm adapted to lie under the nut and be held .thereby, the other arm
locking the nut, and each arm adapted to fit into the said hole or holes, sub
stantially as described.
3. In a nut-lock, the combination, with a polygonal nut, of a washer.held against
turning and having a plurality of holes symmetrically arranged about the nut and
differing by one from the number of sides of the nut, and a key having two reverse
symmetrical arms each equal in height to the thickness of the washer and attached
to a vertical stem, each of said arms adapted to fit into the said holes in the washer,
one arm adapted to lie under the nut and be held thereby, and the other arm
locking the nut, substantially as described.