IMPROVEMENTS IN APPARATUS FOR ROLLING AND IMPRESSING THE SURFACES OF BOLT BLANKS AND OTHER ARTICLES OF METAL, IN EITHER A HOT OR COLD STATE, SO AS TO FORM SCREWS OR PATTERNS THEREON
Year: 1877

page_text: LETTERS PATENT to Charles Fairbairn, of Tonge Villa, Middleton, in the
County of Lancaster, Engineer, for the Invention of
" IMPROVEMENTS IN
APPARATUS FOR ROLLING AND IMPRESSING THE SURFACES OF BOLT BLANKS
AND OTHER ARTICLES OF METAL, IN EITHER A HOT OR COLD STATE, SO AS
TO FORM SCREWS OR PATTERNS THEREON."
Sealed the 20th July 1877, and dated the 19th April 1877.
PROVISIONAL SPECIFICATION left by the said Charles Fairbairn at the Office
of the Commissioners of Patents on the 19th April 1877.
CHARLES FAIRBAIRN, of Tonge Villa, Middleton, in the County of Lancaster,
Engineer. "IMPROVEMENTS IN APPARATUS FOR ROLLING AND IMPRESSING THE
SURFACES OF BOLT BLANKS AND OTHER ARTICLES OF METAL IN EITHER A HOT
OR COLD STATE, SO AS TO FORM SCREWS OR PATTERNS THEREON."
My Invention has reference to the manufacture of screw bolts by forming screw
threads thereon, or patterns on pillars or other articles of metal, by means of rings,
discs, or rollers, and consists with reference to screw bolts, in the use of rings, discs,
or rollers, on the impressing edge or circumference of which are cut grooves of the
required pitch, and at an angle less than is required for the screw threads on the
bolt blanks, but with the complement of the angle made up by setting the rings,
discs, or rollers to the proper inclination by the adjustment of their axes as
required.
When two flat circular plates or discs are used, the requisite grooves are cut on
the peripheries of the discs, on the axes of which are two toothed wheels driven in
their required relative directions by one central wheel. Between these two discs or
rollers the bolt blank is supported, and they are caused in their revolution to act
together on the blank to which they communicate motion and on the surface of which
they impress the threads.
The grooves on the discs or rollers are cut of the same shape as the thread to be
formed on the bolt blank at the front or delivering part of the discs or rollers, but
gradually becoming deeper or wider towards the entering point of the bolt blank.
By this means the thread is raised at the back or bolt blank entering part of the
[Price Gd 1

page_text: disc (when rolling cold iron), the superfluous iron being taken off by the steel cutter
and supported for the bolt blank herein-after described.
The grooves on the discs or rollers are of the pitch required for the threads on the
bolt blank, but the angle thereof is less than is necessary to make the bolt fit a nut,
and this deficiency is made up or compensated for by rendering the axes of the discs
or rollers adjustable, and setting the discs or rollers at the required inclination to
one another. By this means the bolt blank can be caused to revolve under pressure
any number of times determined, and at the same time, owing to the motion_com-
municated by the discs or rollers being placed at an angle, the bolt while being
screwed is also becoming rolled and delivered outwards from the discs or
rollers.
When the impressing discs or rollers are mounted with their centres in a hori-
zontal line, a plain piece of hardened steel is employed as a fixed rest for the support
of the bolt blank while under operation, such rest having a cutting edge and serving
also for a cutter to remove the superfluous metal raised by the deeper grooved part
of the impressing discs or rollers from the revolving bolt, and the said cutter is so
formed that when the threads on the bolt are passing through the finishing
part at the front of the discs or rollers the cutter is clear and inoperative thereon.
When the centres of the discs or rollers are placed otherwise than horizontally,
then two fixed supports or cutters may be used, one on each side of the bolt. The
said cutter is the more necessary when cold iron is being operated upon, as the metal
cannot be stretched or drawn without injury, but it may be dispensed with when
hot iron is employed, as this admits of gradual drawing and stretching, and the
metal may be rendered tougher and more fibrous by the operation. In all cases a
suitable support or supports for the bolt blank will be required.
The apparatus above described may also be adapted and employed for impressing
patterns on pillars or other articles of metal by using dises or rollers with suitable
patterns cut or formed on their peripheries.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Fairbairn in the Great Seal Patent Office on the 17th October
1877.
"
CHARLES FAIRBAIRN, of Tonge Villa, Middleton, in the County of Lancaster,
Engineer. IMPROVEMENTS IN APPARATUS FOR ROLLING AND IMPRESSING THE
SURFACES OF BOLT BLANKS AND OTHER ARTICLES OF METAL IN EITHER A HOT OR
COLD STATE, SO AS TO FORM SCREWS OR PATTERNS THEREON."
"
My Invention of " Improvements in Apparatus for Rolling and Impressing the
Surfaces of Bolt Blanks and other Articles of Metal in either a Hot or Cold State,
so as to form Screws or Patterns thereon has reference to the manufacture of screw
bolts by forming screw threads thereon, or patterns on pillars or other articles of
metal, by means of rings, discs, or rollers, and consists with reference to screw bolts
in the use of rings, discs, or rollers, in the impressing edge or circumference of which
are cut grooves of the required pitch, and at an angle less than is required for the
screw threads on the bolt blanks, but with tho complement of the angle made up by
setting the rings, discs, or rollers to the proper inclination by the adjustment of their
axes, as required.
When two flat circular plates or discs are used, the requisite grooves are cut on
the peripheries of the discs, on the axes of which are two toothed wheels, driven in
their required relative directions by one central wheel. Between these two discs or
rollers, the bolt blank is supported, and they are caused in their revolution to act
together on the blank, to which they communicate motion, and on the surface of
which they impress the threads.
The grooves on the discs or rollers are cut of the same shape as the thread to be

page_text: corresponding screws. By this means when the cams v, v, in their revolution raise
the ends of the levers o, o, the discs c, o, are caused to approach each other and close
on the bolt blank.
The method of working the machine is as follows:-The bolt blank, either in a
cold or heated state, is placed on the rest u between the discs c, c; the cams v, v, in
their revolution raise the ends of the levers o, o, which are thereby caused to move
forward the supports h, h, and press the bolt blank between the discs. The discs in
their revolution communicate their motion to the bolt blank under pressure, and in
this manner form the thread on the blank.
The discs are more deeply threaded at the back or bolt entering part of the disc
(when rolling cold iron), the superfluous iron being taken off by the steel cutter or
support in the manner herein-before described.
From the above described arrangement adapted for rolling and impressing the
surfaces of bolt blanks in a machine with two discs, it will be readily under-
stood that the same principle of arrangement may be adapted for the use of an
increased number of discs by dividing the angle or pitch of the thread on the discs
into two lesser angles, one of which is given to the relative position of the discs, and
the other to the angle or pitch at which the thread is to be cut on the peripheries
of the discs or rolls or rings, the two combined making or furnishing the angle
required. But the inclined position of the discs or rings themselves may remain at
a fixed angle, that is to say, it does not require to be altered, and the angle or pitch
of the thread on the discs or rings may be varied to suit any required pitch, which
may be found by substracting the fixed angle of the discs from the total or required
angle, when the remainder will shew the angle at which the thread is to be cut on
the discs. By this means there would be no alteration required to be made in the
machine for different pitches or angles for different threads, as the shafts and discs
could all be fixed in one position. Three or more discs or rings can be arranged to
be driven either by one central wheel or an annular wheel, and the movement for
closing and opening the space between two of the discs or rings for operating on
the bolt blank and releasing it after operation would remain as shewn and
described.
Having thus described the nature of the said Invention and in what manner the
same is to be performed, I hereby declare that I do not claim as of my Invention
any of the parts of the machine above described except when used in combination
for the purpose described; but what I do claim as of my Invention is,-
First. The arrangement of apparatus or mechanism adapted for the use of rings,
discs, or rollers, having cut on their impressing edge or circumference grooves of the
required pitch, and at an angle less than is required for the screw threads to
be formed on the bolt blanks, but with the complement of such angle made up
by setting the rings, discs, or rollers to the proper inclination by the adjustment
of their axes, as required.
And, Secondly. The machine represented and described adapted for the use of two
discs for the purpose as herein-before described.
In witness whereof, I, the said Charles Fairbairn, have hereunto set my hand
and seal, the Fifteenth day of October, in the year of Our Lord One
thousand eight hundred and seventy-seven.
Witness,
JOHN MATTHEW,
Engineer,
Middleton.
CHARLES FAIRBAIRN. (L.S.)