IMPROVEMENTS IN LOCKING NUTS
Year: 1885

page_text: I, CHARLES HENDERSON, of 9 York Street in the City of Glasgow, Engineer, do
hereby declare the nature of my Invention for "IMPROVEMENTS IN LOCKING
NUTS," to be as follows:-
The object of my Invention is to provide a safe and reliable locking nut for the
fish plate bolts of railways, and for other purposes.
I form a self-locking nut by tapping a nut of any shape in the ordinary way,
and afterwards subjecting a short part of its depth, extending for example over
several threads of the screw, to compression by means of a cress or die or other
device, whereby the diameter of the tapped hole is slightly reduced or tapered
towards the outer edge or face of the nut. When the nut is screwed upon the bolt,
this compressed part has an increased gripping effect which prevents unscrewing
by vibration such as occurs with ordinary nuts. In the case of. large nuts for
which considerable power may be required in compressing the metal I may form
on the outer face of the nut a shoulder or portion of less diameter than the main
part of the nut, and this part alone I subject to compression to lessen the diameter
of the tapped hole at the outer end. In another plan I adopt for compressing part
of the nut and tapering the tapped hole at its outer end, I form a groove or
channel around the tapped hole in the nut. I fit over or into the groove a punch
or tool having V-like edges fitting the groove, and by the blow of a hammer
I force the punch into the groove, whereby the metal at the outer end of the nut is
pressed in wards upon the bolt by a wedge-like action in a manner to reduce the
diameter of the tapped hole.
In each case the compression of the outer end of the nut may be effected either
before the nut is fitted upon the bolt or after it is screwed up in place.

page_text: I, CHARLES HENDERSON, of 9 York Street, in the city of Glasgow Engineer,
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:-
The object of my invention is to provide a safe and reliable locking nut for the
fish plate bolts of railways and for other purposes.
In order that the nature and novelty of my said invention and mode and means
of performing or putting the same into effect or practice, may be properly under-
stood, I shall now proceed to describe the same in and by the following statement
in writing, reference being had to the accompanying Sheet of Drawings which
I have hereunto appended for that purpose.
Referring to Figures 1, 2, 3 and 4, I form a self-locking nut by tapping a nut of
any shape or form in the ordinary way, (one of which forms is shown in section
at A Figure 1), and afterwards subjecting a short part of its depth, (extending for
example, over several threads of the screw) to compression (as shown at a in
Figures and 3), by means of a cress or die as shown in section in Figure 4, or
other device, whereby the diameter U, of the tapped hole is slightly reduced or
tapered towards the other edge or face of the nut at a¹. When the nut is screwed
upon the bolt, this compressed part a¹, has an increased gripping effect on the screw
bolt, which prevents unscrewing by vibration, cuch as occurs with ordinary nuto,
and cannot be unscrewed without the aid of a spanner.
Referring to Figures 5, 6 7, and 8,-In the case of large nuts for which con-
siderable power may be required in compressing the metal, I may form on the
outer face of the nut a shoulder of any convenient form (such for example as is
shown at b on the nut B Figure 5) or portion of less diameter than the main part
of the nut, and this part alone I subject to compression by a cress or die, (such for
example as that shown at Figure 8, to lessen the diameter of the tapped hole at
the outer end, as shown at b¹ in Figures 6 and 7.
Referring to Figures 9, 10, 11, and 12.-By another plan I adopt for compressing
part of the nut and tapering the tapped hole at its outer end I form a groove or
channel of any suitable form or shape (such for example as is shown at c Figure 9,)
around the tapped hole in the nut C. Into this groove c I fit and compress &
punch or tool having V like edges fitting the groove, as for example shown at D in
Figure 12), and by the blow of a hammer, or it might be by pressure, I force
the punch D (Figure 12) into the groove c, whereby the inner rim b of metal at
the outer end of the nut is pressed inwards by a wedge like action to reduce the
internal diameter of the outer thread part at b₁, and thereby grip the bolt very
firmly.
In each case the compression of the outer end of the nut is preferably effected
before the nut is fitted upon the bolt, but this may be done in some cases after the
nut is screwed up in place.

page_text: These improvements are applicable to any shape or form of nut or other hollow
internally screwed metal article. And the essential feature of novelty consists in
compressing the internal threads at the outer end of the nut in a tapered circular
form without distorting them, and without making radial cuts or slots through the
body of the nuts as has sometimes heretofore been done.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
In so called locking or holdfast nuts, the compressing of the solid metal at the
outer ends of such nuts or other hollow screws to reduce the diameter of the
threads at or near to the outer end of the nut in a true circular conoidal manner
without distorting the threads, all substantially as and for the purposes herein
before set forth.