IMPROVEMENTS IN LOCKING SCREWS AND THE NUTS OF BOLTS, AS ALSO IN PREVENTING AN UNEQUAL STRAINING OF THEIR THREADS
Year: 1865

page_text: LETTERS PATENT to Frederick Arthur Paget, of 18, Adam Street. Adelphi,
in the County of Middlesex. Civil Engineer, for the invention of
"IMPROVEMENTS IN LOCKING SCREWS AND THE NUTS OF BOLTS, AS ALSO
IN PREVENTING AN UNEQUAL STRAINING OF THEIR THREADS."
Sealed the 24th November 1865, and dated the 29th May 1865.
PROVISIONAL SPECIFICATION left by the said Frederick Arthur Paget
at the Office of the Commissioners of Patents. with his Petition, on the
29th May 1865.
1, FREDERICK ARTHUR PAGET. of 18. Adam Street. Adelphi, in the County
of Middlesex. Civil Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN LOCKING SCREWS AND THE NUTS OF BOLTS, AS ALSO
IN PREVENTING AN UNEQUAL STRAINING OF THEIR THREADS," to be as follows:-
It is well known that the ordinary screw and nut or female thread, even
when well made, and still more so with inferior workmanship. are subject to
several disadvantages. In the first place any jar or vibration tends to shake
and sooner or later always does shake off the nut from the screw; this takes
place with any screw and nut or male and female thread, and still more so
when, as is mostly the case, there is any slight play or looseness between the
surfaces of the threads. Many contrivances have been invented to prevent
this action, but few have been found successful, and not one is applicable to
all cases. In the next place, unless the surfaces of contact between the nut
and washer, or between the nut and thing screwed up, be true, the evil results
of any jar are yet more felt, and the threads are very liable to be strained
[Price 8d.1

page_text: unequally. One of the contrivances commonly used for preventing a nut
from shaking itself loose off the screw consists in the use of two nuts, one
above another, the top nut going by the name of the jamb or lock nut.
Among other difficulties the lock nut is more peculiarly inconvenient when
used for details requiring an exact adjustment, such as the brasses of bearings.
When the lock nut is screwed down on the bottom nut, the latter naturally
gives way to this lock nut by the amount of its vertical play or looseness on
the screw. In this way the brasses for instance of a bearing often get
screwed down too tightly. Now I avoid all these difliculties by the use of a
washer formed in the following manner:-- make it of steel, and of such a
form that the screwing down of the nut of the screw brings the washer into a
state of initial strain. This I generally do by hollowing out the steel washer
on its under side. Sometimes I form a number of concentric corrugations in
the steel washer; at other times I form it of one or more dished steel plates
or discs. I also sometimes mill or serrate the surfaces of contact of the
washer and its nut, and the spring of the washer allows these surfaces to pass
each other, and afterwards to mutually interlock. Sometimes I turn a groove
in the bottom part of the nut or head of the screw, into which I insert a spring.
Now by means of the spring, or the initial strain induced by screwing up in
line the steel washer or spring. I find that I obviate all the above-mentioned
difficulties. In the first place, the spring of the washer compensates for any
looseness between the male and female screws. the surfaces of which are kept
tight against each other. The spring washer always follows up the nut on the
screw keeping up a due amount of friction, and preventing any moving back
through vibration. When again the surfaces are not true. that is to say,
when the surfaces that ought to bed against each other do not form planes al
right angles to the axis of the screw, one portion of the washer yields more or
less, preventing a side strain on the threads. Furthermore, the difficulty.
mentioned above generally to be encountered when jamb nuts are used is
obviated by the use of the spring washer.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Arthur Paget in the Great Seal Patent Office on
the 29th November 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I. FREDERICK
ARTHUR PAGET. of 18. Adam Street, Adelphi, in the County of Middlesex,
Civil Engineer, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of May, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of
1er reign did, for Herself. Her heirs and successors, give and grant unto
me, the said Frederick Arthur Paget, Her special licence that I, the said
Frederick Arthur Paget, my executors, administrators, and assigns. or such
others as 1. the said Frederick Arthur Paget, my executors. administrators.
and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed. should and
lawfully might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN LOCKING SCREWS AND THE NUTS OF BOLTS, AS ALSO IN
PREVENTING AN UNEQUAL STRAINING OF THEIR THREADS," upon the condition
(amongst others) that 1. the said Frederick Arthur Paget. my executors or
administrators. by an instrument in writing under my, or their. or one of their
hands and seals. should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed. and
cause the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I. the said Frederick Arthur Paget, do hereby declare
the nature of my said Invention. and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, that is
to say:- -
It is well known that the ordinary screw and nut or female thread. even
when well made, and still more so with inferior workmanship. are subject to
several disadvantages. In the first place any jar or vibration tends to shake
and sooner or later always does shake off the nut from the screw; this takes
place with any screw and nut or male and female thread, and still more so
when, as is mostly the case, there is any slight play or looseness between the
surfaces of the threads. Many contrivances have been invented to prevent
this action, but few have been found successful. and not one is applicable to
all cases. In the next place unless the surfaces of contact between the nut
and washer, or between the nut and thing screwed up, be true, the evil results
of any jar are yet more felt. and the threads are very liable to be strained
unequally. One of the contrivances commonly used for preventing a nut from
shaking itself loose off the screw consists in the use of two nuts, one above the
other, the top nut going by the name of the jamb or lock nut. Among other
difficulties the lock nut is more peculiarly inconvenient when used for details

page_text: requiring an exact adjustment, such as the brasses of bearings. When the
lock nut is screwed down on the bottom mut the latter naturally gives way to
this lock nut by the amount of its vertical play or looseness on the screw. In
this way the brasses, for instance, of bearings often get screwed down too
tightly. Now I avoid all these difficulties by the use of a washer formed in
the following manner: I make it of steel, and of such a form that the
screwing down of the nut or of the screw brings the washer into a state of
initial strain; this generally do by hollowing out the steel washer on its
under side.
The accompanying Drawings shew three different forms of a steel washer
according to this Invention, though it is evident that a great variety of
more or less similar shapes can be employed.
Sometimes form a number of concentric corrugations in the steel washer;
at other times I form it of one or more dished steel plates or discs. In some
cases I fill up, or parily fill up, these hollows by means of such elastic vegetable
gums as gutta percha or india-rubber. I also sometimes millor serrate the
surfaces of contact of the washer and its nut; and the spring of the washer
allows these surfaces to pass each other, and afterwards to naturally interlock.
Sometimes I turn a groove in the bottom part of the nut or head of the screw,
into which insert a spring. Now by means of the spring or the initial strain
induced by screwing up in line the steel washer or spring I find that I obviate
all the above-mentioned difficulties. In the first place, the spring of the
washer compensates for any looseness between the male and female screws,
the surfaces of which are kept tight against each other. The spring washer
always follows up the nut or the screw, keeping up a due amount of friction,
and preventing any moving back through vibration. When again the surfaces
are not true, that is to say, when the surfaces that ought to bed against each
other do not form planes at right angles to the axis of the screw, one portion
of the washer yields more or less, preventing a side strain on the threads.
Furthermore the difficulty mentioned above, generally to be encountered
when jamb nuts are used, is obviated by the use of the spring washer.
It is well known that there are several ways of forming such washers, as
they may be turned in a lathe or stamped out of plate between a die and
matrix. Of the two modes I prefer the latter as being the least expensive.
And having now described the nature of my said Invention, and the manner
in which the same may be carried into effect, I wish it to be understood that
I do not confine or limit myself to the precise shapes and arrangements as
shown and described, as the same may be almost infinitely varied without
departing from my Invention; but what I do claim as my Invention is, the

page_text: adoption for locking screws and nuts, and for equably adjusting the strain on
the threads, of a steel washer of such a shape as to cause it to develop more
or less elasticity when compressed at right angles to its central axis.
In witness whereof, I, the said Frederick Arthur Paget, have hereunto
set my hand and seal, this Twenty-ninth day of November, One thou-
said eight hundred and sixty-five.
Wilness,
Ebw". G. BREWER,
89. Chancery Lane, W.C.
F. A". PAGET. (L.s.)