IMPROVEMENTS IN LOCKING BOLTS AND NUTS
Year: 1886

page_text: We ROBERT SIMPSON, HENRY SIMPSON and BENJAMIN GREAVES SIMPSON, all
of Heeley Old Mill Sheffield in the County of York, Manufacturers do hereby
declare the nature of our said invention for IMPROVEMENTS IN LOCKING BOLTS AND
NUTS to be as follows:-
"
Our invention is to obtain a simple and effective method of securing, either
permanently or otherwise, the nuts of bolts or other similar screws
That they
shall not become loose or unscrewed.
"
To accomplish this we prefer to use a nut of rather greater depth than usual,
but this is not an essential part of the invention; the top portion of the tapped
hole is made conical or bell mouthed, and this may be done either by a suitable
punch before tapping the thread, or it may be accomplished by a taper tap..
The end of the screw or bolt is provided with a sawgate or slit made longi-
tudinally through its axial line. When the bolt is screwed into the nut, or the nut
upon the bolt, a wedge is driven into the sawgate or slit so as to expand the end
of the bolt into the conéd part of the nut. The wedge may be either removed or
left in,
.

page_text: We ROBERT SIMPSON, HENRY SIMPSON and BENJAMIN GREAVES SIMPSON, all
of Heeley Old Mill, Sheffield, in the County of York, Manufacturers, do hereby
declare the nature of our invention for IMPROVEMENTS IN LOCKING BOLTS AND
NUTS and in what manner the same is to be performed; to be particularly described
and ascertained in and by the following statement :-
Our invention has for its object to obtain a simple and effective method of
securing the nuts of bolts or other similar screws, so that they cannot be shaken
loose or become unscrewed therefrom, and such fastening may be either a permanent
one or otherwise.
And in order that our invention may be clearly defined from others, and under-
stood we have hereunto annexed a sheet of explanatory drawings, in which the
same letters of reference indicate the same parts in any of the figures in which
they occur.
Fig. 1 represents a bolt, with the nut screwed down to position, ready for the
insertion of wedge.
Fig. 2, represents the same with the wedge driven in, and the edges of split end
of bolt turned over it.
Fig. 3. a modified construction of nut.
In carrying out our invention we prefer to make the nut of rather greater depth
than usual, but this is not essential; and we make the top portion of the bolt hole
conical or bellmouthed, and either plain as shown in Fig. 3, or with a screw thread
as shown in Fig. 1.
If the taper or coned part A of the nut is to be plain, it may be formed by a
coned punch during the process of manufacture, and if with a screw thread, this
may be done with a special taper tap or by other suitable means,
The bolt or screw to be used in connection with this coned nut, is slit, divided,
or sawgated longitudinally, from the point to a suitable distance down the screwed
shank B.
-
When put into use and the nut screwed down as in Fig. 1, a small wedge C, is
inserted in the sawgate D, and driven downwards so as to expand and force back
the divided parts or end of the bolt into the position as shown in Fig. 2, thus
rendering it quite impossible for the nut to be unscrewed or withdrawn from the
expanded or enlarged end of the bolt. When it is desired to make the fastening
permanent, the ends of the bolt are rivetted over the head of the wedge so that it
cannot be shaken out.
Although v we use a bolt or screw the end of which is divided longitudinally by
a sawgate, or by other similar means, we are aware that divided bolts are old and
therefore do not claim them as of our invention.

page_text: Having thus particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1-As a means of "locking" bolts and nuts, making the top portion of the hole
in the nut conical or bell mouthed, and either with or without screwthreads, for
the purpose of receiving the expanded or pressed back ends of a split end bolt
substantially as described and illustrated,
2-The combination of a coned nut, such as A, a split end bolt, such as B, and
a wedge, such as C, for the purpose specified and substantially as hereinbefore
described and shown.