IMPROVEMENTS IN BOLT- MAKING MACHINERY
Year: 1871

page_text: LETTERS PATENT to Charles Fairbairn, of Marion Villa, Sciennes,
Edinburgh, Engineer, for the Invention of "IMPROVEMENTS IN BOLT-
MAKING MACHINERY."
Sealed the 3rd April 1872, and dated the 6th November 1871.
PROVISIONAL SPECIFICATION left by the said Charles Fairbairn at the
Office of the Commissioners of Patents, with his Petition, on the
6th November 1871.
I, CHARLES FAIRBAIRN, of Marion Villa, Sciennes, Edinburgh,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN BOLT-MAKING MACHINERY," to be as follows:-
My Invention relates in the first place to a machine for rolling
square-necked bolts from a square or round bar of heated iron, and
consists in mounting in suitable standards two shafts carrying suitably
grooved rollers with spaces left in the grooves for making square heads
and necks, such rollers by means of a lever fixed to one of the said two
shafts or axles of the rollers, and worked by a crank, being caused to
revolve a certain distance and then return, delivering at the same time

page_text: two bolts connected at the heads; or by means of suitable gearing the
rollers may be made to revolve continuously, thereby making at the
same time a series of bolts. The bolts are cut off by a knife or cutter
fixed to the apparatus. They are then headed and screwed.
In the former case (that is when only two bolts are made at once) by
altering the crank pin the length of the bolts can be regulated, and by
shortening or lengthening the connecting rod as required the spaces for
the heads in the two corresponding rollers are brought together at the
proper place. The said square or round bar of heated iron is first
passed through oval grooves in the rollers to shape it as required,
and then through circular grooves in the same to finish the round
part of the bolts.
In the latter case (that is where a series of bolts are delivered at once)
the spaces for the heads and necks may be multiplied round the rollers,
so as to admit of a series of bolts being rolled and manufactured.
After the bolts are rolled to the size required they are put through the
second operation, namely the screwing.
And my Invention relates in the second place to a machine for forming
screw threads on iron bolts or screw blanks while in a moderately
heated state (say immediately after passing through the rolling machine
above described and before cooling) or in a cold state, and consists in
the use of properly grooved screw plates, worked by a double lever
(worked by a crank) and two connecting rods or other suitable
mechanism, and caused to move simultaneously in opposite directions
so as to act on opposite sides of the bolt or screw blank, and impress it
with the reverse of the grooves formed in the plates, such grooves being
cut to the proper angle required for the screw. By the motion of the
said two plates in opposite directions the bolt or screw blank is caused
to revolve rapidly and is thus threaded round and true.
For long bolts these screw plates may be made alternately with
grooves and vacant spaces. Moreover, the said plates may be grooved
parallel to their sides, in which case the bolt or screw blank would have
to be placed and held at the required angle by means of guides or
holders fixed on the side of the frame in which the bolt revolves.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Fairbairn in the Great Seal Patent Office
on the 6th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
FAIRBAIRN, of Marion Villa, Sciennes, Edinburgh, Engineer, send
greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of November, in the
year of our Lord One thousand eight hundred and seventy-one, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said Charles Fairbairn, Her special
licence that I, the said Charles Fairbairn, my executors, administrators,
and assigns, or such others as I, the said Charles Fairbairn, 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 Invention for "IMPROVEMENTS IN BOLT-
MAKING MACHINERY," upon the condition (amongst others) that I, the said
Charles Fairbairn, 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 Scal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Charles Fairbairn, 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 here-
unto annexed, and to the letters and figures marked thereon (that is
to say) :-
My Invention of "Improvements in Bolt-making Machinery" relates
in the first place to a machine for rolling square-necked bolts from a
square or round bar of heated iron, and consists in mounting in suitable

page_text: standards two shafts carrying suitably grooved rollers with spaces left in
the grooves for making square heads and necks, such rollers by means
of a lever fixed to one of the said two shafts or axles of the rollers and
worked by a crank, being caused to revolve a certain distance and then
return, delivering at the same time two bolts connected at the heads; or
by means of suitable gearing the rollers may be made to revolve con-
tinuously, thereby making at the same time a series of bolts. The bolts
are cut off by a knife or cutter fixed to the apparatus. They are then
headed and screwed.
In the former case (that is when only two bolts are made at once) by
altering the crank pin the length of the bolts can be regulated, and by
shortening or lengthening the connecting rod as required the spaces for
the heads in the two corresponding rollers are brought together at the
proper place. The said square or round bar of heated iron is first passed
through oval grooves in the rollers to shape it as required, and then
through circular grooves in the same to finish the round part of the
bolts.
The
In the latter case (that is where a series of bolts are delivered at once)
the spaces for the heads and necks may be multiplied round the rollers,
so as to admit of a series of bolts being rolled and manufactured.
bolts thus beaded (and previous to their being screwed) may be rendered
uniform at the points by passing them through rollers in the manner
herein-after described.
After the bolts are rolled to the size required they are put through
the second operation (namely the screwing) while in a moderately 1
heated state (say immediately after passing through the rolling machine
above described and before cooling) or in a cold state by being passed
between two properly grooved screw plates worked by a double lever
(worked by a crank) and two connecting rods or other suitable
mechanism, and caused to move simultaneously in opposite directions
so as to act on opposite sides of the bolt or screw blank, and impress it
with the reverse of the grooves formed in the plates, such grooves being
cut to the proper angle required for the screw. By the motion of the
said two plates in opposite directions the bolt or screw blank is caused
to revolve rapidly, and is thus threaded round and true.
For long bolts these screw plates may be made alternately with
grooves and vacant spaces. Moreover, the said plates may be grooved

page_text: parallel to their sides, in which case the bolt or screw blank would have
to be placed and held at the required angle by means of guides or
holders fixed on the side of the frame in which the bolt revolves.
The said screwing apparatus may be modified, especially for small
bolts, in the manner herein-after described.
Having thus stated the nature of the said Invention, I will proceed
to describe more particularly in what manner the same is to be per-
formed by the aid of the accompanying Drawings, in which are
represented the rolling and screwing machinery or apparatus above
referred to.
Fig. 1 is an end elevation and Fig. 2 a side elevation of the machine
for rolling a square or round bar of heated iron into the requisite shape
for forming bolts. In these two Figures a' and a³ are the shaping
rollers, which in Fig. 2 are shewn as having grooves cut in them for
the purpose of forming on the screw blanks or bolts the square and
round parts as required; 6 is the lever fixed to the lower roller shaft,
and intended to be connected at the upper end to a crank, by which it is
worked. In Fig. 2 will be seen the oval and circular spaces of different
sizes between the rollers, through which the iron is successively passed
in order to form it into the screw blanks or bolts required.
At Fig. 3 the rollers a' and a³ are shewn detached in transverse
section, and represented as made square for two heads on each side.
Instead of this form the rollers may be made so as to form more heads
or only one as may be desired. c, c, is the toothed gearing for working
the top roller.
After the screw blanks or bolts are formed and headed in this
machine, and before they are screwed by the means herein-after
described, in order to make their points uniform in size and to make
the nuts fit them exactly, the screw blanks or bolts may have their
points passed between two plain revolving rollers in an oblique
direction, that is to say, the screw blanks or bolts are put through the
rollers at a slight angle so as to admit of their revolving freely by their
contact with the two rollers. The rollers are adjustable by means of
screws to allow screw blanks or bolts of different sizes being passed
through them. The rollers are also of different diameters, and make the

page_text: same number of revolutions; but the roller of larger diameter passes
through more space than the smaller one. The inner operating surface
of the larger roller passes downwards and that of the smaller roller
upwards. The screw blank or bolt on which the screw is afterwards to
be impressed is inserted in a heated state between the two rollers, with
its point at an angle to the axes of the rollers, and caused to revolve
between them. The large roller imparts a greater revolving motion to
the screw blank or bolt than the smaller one does; but this difference
is made up by the screw blank or bolt gradually moving downwards
over the surface of the smaller roller until it passes out from between
the two rollers. By the above-described means any required number of
screw blanks or bolts may be made uniform in size and perfectly round
at the points.
Fig. 4 is a side elevation and Fig. 5 an end elevation of the screwing
machine. a, d³, are sliding blocks which serve as carriers for the
screwing plates; e¹, e³, are fixed bars or horizontal guides for the sliding
blocks, which are worked to and fro thereon in opposite directions by
means of the oscillating double lever f acting on a centre 9. The bars or
guides e¹, e³, are weighted, as shewn, by means of bolts passing down
through the framing, through the lower end of each of which bolts is
passed a lever i having its fulcrum on the framing at k, and held down
at its other end by a weight l.
At Fig. 6 is represented in face view a screwing plate, and at Fig. 7
in transverse section two plates m. Fig. 4 is the screw blank or bolt
intended to have the screw thread impressed on it.
Figures 8 and 9 represent a modification of the screwing apparatus
intended for small bolts. In this case instead of using flat screwing
surfaces or plates circular surfaces or discs are employed. In Fig. 8 it
will be seen that there are three discs n', n², n³, with screw threads cut
on their circumferences, two discs n¹ and n² being on a line and the
third disc below them, the latter being adjustable vertically. These
three discs are driven by a pulley O, and communicate by gearing p, q.
The lower disc n³ is adjusted vertically as required by means of an
excentric and a lever 8. The end of the screw or bolt t'intended to be
screwed is inserted between the three discs, and has the screw thread
impressed upon it by the revolution of the discs. u is a bridle carrying
the journals of the lower disc n³, which the excentric acts upon for
the purpose of raising and lowering it.

page_text: Having thus described the nature of the said Invention, and in what
manner the same is to be performed, I hereby declare that what I claim
as of the said Invention is,―-
First. The machinery or apparatus for forming screw blanks or bolts
by rolling them out of square or round bars of heated iron as herein-
before described.
And secondly. The machinery or apparatus for impressing screw
threads on the screw blanks or bolts so formed by rolling, such
machinery or apparatus consisting of screw plates or impressing surfaces
suitably worked and caused to act on the screw blank or bolt placed
between them as herein-before described.
In witness whereof, I, the said Charles Fairbairn, have hereunto
set my hand and seal, the Second day of May, in the year of
our Lord One thousand eight hundred and seventy-two.
DONALD MACKAY,
Witness.
CHARLES FAIRBAIRN. (L.S.)