Year: 1888

page_text: I, EDWARD CHARLES IBBOTSON of Victoria Road, Sheffield, in the County of York,
Merchant, 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:-
My invention of improvements in Locknuts relates to the construction of nuts for
bolts and other like screws, by which they are enabled to grip the said bolts or
other screws firmly, and are thereby prevented from becoming loose, or unscrewed by
vibration or other cause.
or more
In carrying out my invention, according to the first method I make a nut of
ordinary construction, and cut transversely to a suitable depth one
grooves or crosscuts at one end, so as to render this end of the nut expansible
radially.
The nut being tapped or screwthreaded in the usual manner, I depress one or more
of the top threads at the crosscut end, by means of the blow of a hammer, or by the
application of pressure, or other like means, so as to narrow or partially close the
spaco between the threads, and that my invention may be very clearly understood
I have illustrated the two methods of carrying it into effect, in the annexed sheet of
drawings.
Fig. 1, section of an ordinary nut with crosscuts, bofore compression.
Fig. 2 the same with top threads compressed.
Fig. 3-plan of same.
Fig. 4 section of nut with partly cut threads in the crosscut end.
The crosscuts are marked A, the solid part of the nut B, the depressed threads C, C.
It will be obvious that when the end of an ordinary bolt, upon which the nuts so
constructed is being screwed, enters the compressed and partially closed spaces between
the depressed threads C, C, the threads upon the bolt cannot enter the narrowed
spaces to the full extent or depth, and thus the parts of the nut divided by the cross-
cuts are caused to expand radially to permit the bolt to enter, and to grip the bolt
firmly by the inherent elasticity of the metal.
The construction of the nut is clearly illustrated in Figs. 1. 2. & 3.

page_text: In the second method of carrying out my invention in constructing a nut that will
expand radially at one end, when screwed upon a corresponding bolt or screw, I cross-
cut one end of the nut as before decribed, and the bore, or untapped hole, is made
parallel from end to end as in the former case.
In forming the threads of the nut which may be accomplished by any suitablo
means, the threads in the lower part are made of the full depth, and complete in form
as usual, but in making the threads I use a taper tap or other suitable appliance so
constructed as to leave one or more circles D of the thread at the crosscut end of the
nut, not fully cut, that is, they are not so deeply cut as the others, and thus the bolt
or other screw when made to pass through the said partially cut threads, by the appli-
cation of force, will cause the crosscut end to be expanded radially and thereby grip
the bolt with considerable power preventing the nut becoming loose or turning upon
the bolt by vibration or otherwise.
It will be understood that in both the methods now described I retain the bore of
the nut of unvarying (or equal) diameter throughout, and also that the same result is
attained by the passage of the holt, namely the radial expansion of the crosscut or
divided end of the nut, causing an elastic grip upon the bolt.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same may be carried into effect, I declare that what
1 claim is
1-A nut of any suitable material, having at one end, either one or more transverso
cuts or sawgates of any required depth, and with one or more circles of the thread at
the crosscut end, compressed in such a manner as to narrow or contract the spaces
between the threads, for the purpose specified and substantially as hereinbefore
described and as shown in Figs. 1. 2. 3.
2-A screwthreaded nut of any suitable material having transverse cuts or sawgates
at one end, and with one or more threads at the crosscut end only, partially, or not
fully cut in depth for the special purpose hereinbefore specified, and substantially as
described and shown in Fig. 4.
Dated the 9th day of March 1800