IMPROVEMENTS IN NUTS FOR SCREW BOLTS."
Year: 1876

page_text: LETTERS PATENT to Roland Harrington, of Wolverhampton, in the County of
Stafford, for the Invention of "IMPROVEMENTS IN NUTS FOR SCREW BOLTS."
PROVISIONAL SPECIFICATION left by the said Roland Harrington at the
Office of the Commissioners of Patents on the 7th November 1876.
ROLAND HARRINGTON, of Wolverhampton, in the County of Stafford. "IMPROVE-
MENTS IN NUTS FOR SCREW BOLTS."
This Invention has for its object an improved method of constructing nuts used
for screw bolts, so that such nuts shall be prevented from becoming loose or
unscrewed, but shall be locked or fixed in the position in which it is desired that
they shall remain when screwed up. It is applicable to the bolts used for fish
plates upon railways, or in other conditions where the nuts are liable to become
loose or unscrewed by vibration.
I make a nut of sufficiently elastic material; preferably steel, and I cut it or make
an opening completely through at one side of its circumference. I screw this nut
inside with a thread corresponding with that of the bolt upon which it is to be fitted,
but I make the diameter of this screwed thread somewhat smaller than that of the
bolt, so that considerable force is necessary to screw it upon the bolt, in doing.
which the elasticity of the material allows the opening described at the side of the
nut to become expanded.
The outer circumference of the nut as described may be square or polygonal, so
that it can be turned round by a key or wrench in the usual manner, or it may be
provided with projections, by which it may be turned round in the same way. The
elasticity of the nut forced upon the screwed bolt in the manner described is
sufficient to retain it in the position into which it is brought upon the bolt without
the liability of its becoming loose by vibration.
Nuts constructed as described may be used either as lock nuts forced down

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Roland Harrington in the Great Seal Patent Office on the 7th May
1877.
ROLAND HARRINGTON, of Wolverhampton, in the County of Stafford. " IMPROVE-
MENTS IN NUTS FOR SCREW BOLTS."
This Invention relates to the "nuts" used for screwed bolts, and has for its object
an improved method of constructing such nuts, by which method the nuts are
prevented from becoming loose or unscrewed upon the bolts, but remain locked or
fixed in the position in which it is desired that they shall remain when screwed up.
My Invention is applicable to the bolts used for attaching fish plates to the rails
upon railways, or to other conditions where the nuts are liable to become accident-
ally loose or unscrewed upon their bolts by vibration or other cause.
In making a nut according to my Invention I form it, by forging, stamping, or
other means well known and practised, out of sufficiently elastic material, preferably
steel, and when finished I cut it completely through one part of its circumference.
I screw the inside of it with a thread corresponding with that of the bolt upon
which it is to be screwed, but I make the diameter of its screwed thread somewhat
less than that of the bolt, so that considerable force is necessary to screw it upon
the bolt, in doing which the elasticity of the material allows the cut or opening
already described at the circumference of the nut to become expanded, and the
latter is retained in any desired position upon the bolt by its tendency to contract.
The openings may be formed when the nut is made, instead of being afterwards
cut.
The outer circumference of the nut may be square or polygonal, so that it can be
turned round by a key or wrench in the usual manner, or it may be provided with
projections or holes by which it may be turned round and screwed up or unscrewed
in the same way. The screwed thread in the nut may be made either before or
after the cut or opening has been made through the circumference of the latter,
and the cut though preferably radial may be made tangential or in any other
desired direction. The edges of the threads at the opening may be bevilled off.
Nuts constructed according to my Invention may be used either as lock nuts
forced down against ordinary nuts screwed upon the bolts in the usual way, or
they may themselves be used as such principal nuts with or without lock nuts
above them.
The accompanying Drawing is in illustration of my Invention.
Figure 1 shews a bolt having a hexagonal nut constructed according to my
Invention screwed upon it; Figure 2 is an end view of the same. a is the nut,
and b the cut or opening through its circumference.
Figure 3 shews a bolt having an ordinary nut screwed upon it, and a lock nut
constructed according to my Invention screwed against the latter; Figure 4 is an
end view.
a is the bolt; b the ordinary nut, and c the improved lock nut. The latter is
shewn with its circumference round instead of hexagonal, but having a projection d
by which it can be turned round. The cut or opening e is shewn through the
projection d, but it may be made in any other part of the circumference of the lock
nut instead of in the position shewn.
Having now described my Invention and the manner in which it is to be per-
formed, I claim, the method of constructing nuts for screw bolts with a cut or
opening through one part of their circumference, so that their elasticity retains them
in the position to which they have been screwed up, and prevents them from

page_text: becoming accidentally unscrewed, substantially as described and shewn in the
Drawing.
In witness whereof, I, the said Roland Harrington, have hereunto set my
hand and seal, this First day of May, in the year of our Lord One thousand
eight hundred and seventy-seven.
.
ROLAND HARRINGTON. (L.S.)