IM- PROVEMENTS IN PORTABLE MACHINERY FOR TURNING, SCREW CUTTING, BORING, AND SLOTTING, ALSO FOR CUTTING OFF TUBES OR SOLID BARS INTO ANY REQUIRED LENGTHS
Year: 1868

page_text: LETTERS PATENT to Henry George Fairburn, Engineer, of 45, Goswell
Road, E.C., in the County of Middlesex, for the Invention of "IM-
PROVEMENTS IN PORTABLE MACHINERY FOR TURNING, SCREW CUTTING, BORING,
AND SLOTTING, ALSO FOR CUTTING OFF TUBES OR SOLID BARS INTO ANY
REQUIRED LENGTHS."
Sealed the 17th October 1868, and dated the 17th April 1868.
PROVISIONAL SPECIFICATION left by the said Henry George Fairburn
at the Office of the Commissioners of Patents, with his Petition,
on the 17th April 1868.
I, HENRY GEORGE, FAIRBURN, Engineer, of 45, Goswell Road, E.C., in
the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PORTABLE MACHINERY FOR TURNING, SCREW
CUTTING, BORING, AND SLOTTING, ALSO FOR CUTTING OFF TUBES OR SOLID BARS INTO
ANY REQUIRED LENGTHS," to be as follows:-
My Invention consists of a central hollow mandrill or tube which
is secured to the bar or pipe to be turned, screwed, cut, or tapped

page_text: (which passes through it) by means of set screws, keys, clamps, or
other convenient mode. The hollow mandrill has cut upon it one or
more screws of different pitches and of any required length. Around
the hollow mandrill I place another cylinder which has recesses or
mortises for the cutting tools, and is also fitted with dies and set screws,
so that by setting up the dics by means of the screws into the pattern
thread of the pitch required the cylinder is then made to revolve by
means of spur, bevil, or screw wheel gearing, therefore as the cylinder
revolves the die follows the thread of the screw or hollow mandrill,
the cutters are set up to their work, and the screw is accordingly cut
upon the tube or bar which is passed through the hollow mandrill.
When a tube or bar is required to be cut off the screw feed is not in
gear, therefore the cutter as it rotates will follow in its own groove
and is set up or fed by means of a set screw or other convenient mode.
Instead of having the model or pattern screws of different pitches cut
upon the central hollow mandrill, I merely pass through one or more
chisel-pointed dies which are set and secured to any angle according to
pitch required. These dies being secured to the outside cylinder and
revolving round the hollow mandrill cause the same cylinder to move
forwards or backwards according to the angle or pitch of die. I also
attach a plate or disc in connection with the said chisel-pointed dies with
angles graduated and marked so that the angle for any required number
of threads to the inch may be determined upon. Instead of a hollow
mandrill I sometimes use a solid bar fitted with an arm or disc which
carries the cutters. This bar is made to revolve by any suitable hand
or other gearing. The pattern screws may be cut upon this bar, or
instead of the screws for the feed motion chisel-pointed dies may be used
as already described. Sometimes I use revolving discs instead of the
chisel points. The bar, tube, or nut may be turned, bored, or cut off,
the object to be operated on being secured to the same framework that
carries the bar and cutters, but in this case the outside cylinder (as
before described) remains stationary. In cutting slots, straight or spiral
grooves, the cylinder that is around the hollow mandrill (or the mandrill
as may be required) is made to have a reciprocating motion by means
of a connecting link or links from cams or cranks. The connecting link
or links are attached to a ring which clasps the cylinder that has the
cutter or cutters; this ring is in a groove working against collars on
the cylinder. By this arrangement the cylinder may turn round or
partly turn as it would in cutting a spiral groove. Where a straight

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry George Fairburn in the Great Seal Patent
Office on the 17th October 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
GEORGE FAIRBURN, Engineer, of 45, Goswell Road, E.C., in the County
of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of April, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-second
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Henry George-Fairburn, Her special licence that
I, the said Henry George Fairburn, my executors, administrators, and
assigns, or such others as I, the said Henry George Fairburn, 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 PORTABLE MACHINERY FOR TURNING, SCREW CUTTING, BORING, AND SLOTTING,
ALSO FOR CUTTING OFF TUBES OR SOLID BARS INTO ANY REQUIRED LENGTHS,"
upon the condition (amongst others) that I, the said Henry George
Fairburn, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should par-
ticularly 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 Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Henry George Fairburn, 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 thereof, that is to say:-

page_text: The Invention has for its object improvements in portable machinery
for turning, screw cutting, boring, and slotting, also for cutting off
tubes or solid bars into any required lengths. For these purposes a
central hollow mandrill or tube is secured by means of set screws, keys,
clamps, or other convenient method to the bar, pipe, or other article
to be turned, screwed, tapped, or cut off. The said hollow mandrill
has cut upon it, either internally or externally, one or more screw
threads of different pitches and of any required lengths; or the said
screws instead of being cut on the said hollow mandrill may be cut
on rings to be slipped on to the said hollow mandrill and held in position
by means of a groove or feather or other suitable contrivance. Around
the said hollow mandrill I place a cylinder which has recesses or
mortices connected therewith for receiving the cutting or guage tools,
and which is also fitted with dies and set screws, one of which dies
having been set into the pattern screw thread on the said mandrill,
the said cylinder is then caused to revolve by means of spur, bevel,
or screw wheel gearing, and as it revolves the said die following the
course of the said pattern screw thread will impart to the said external
cylinder a forward or backward motion, according to the direction in
which the said external cylinder is turned, and the said cutting tools
made to cut in both forward and reverse motion, being set to their work,
the required screw is cut upon the tube, bar, or other article.
In a modification of the above-described method, instead of having
pattern screw threads cut or placed on the said hollow mandrill I pass
through the said external cylinder one or more chisel-pointed dies or
discs which take on to the said mandrill, and may be set to any angle
according to the pitch of screw required to be cut. The said dies or
discs being secured to the outside cylinder and rotating therewith round
the said mandrill give the said external cylinder a longitudinal motion,
quick or slow, according to the angle or pitch to which the said dies
or discs are set. The said dies or discs or the cutting tools may be set
at any required angle to the bar or tube on which the screw is to be cut
instead of acting on the hollow mandrill as above described, in which
case the cutters or tools would both give the pitch and cut the screw
required. In connection with the said dies, discs, or cutting tools I
use a plate or disc graduated or marked, so that the angle for any
required number of threads to the inch may be readily determined
upon.

page_text: For boring or internal tapping I use a bar or tool holder occu-
pying a similar position to that already described for the pipe or bar
to be tapped, which said tool holder is firmly held within the said
mandrill, while the substance to be bored or internally tapped is held
by the external cylinder and caused thereby to revolve round the tool
in the said tool holder which is stationary; or the said tool holder may
be secured to the said external cylinder and caused to rotate therewith,
in which case the substance to be bored or internally tapped is secured
to the same bed or frame as the said hollow mandrill. This method
may be also adapted for external tapping and the other operations
already described by fixing the bar, pipe, or other article to be operated
upon to the said framework in a line with the central axis of the said
external cylinder and causing the cutters in the said external cylinder
to revolve round it and operate thereon, in which case the said mandrill
might be made solid instead of hollow.
In a modification of the above-described method adopted for boring
or internal tapping the pattern screw threads are cut upon the said
tool holder, which is driven by any suitable gearing, the dies acting
on the said pattern screw threads in a similar manner to that already
described in connection with the hollow mandrill, or dies set at any
required angle may be made to act upon the said tool holder instead of
upon the said hollow mandrill. In cutting straight or spiral grooves
a reciprocatory motion is given to the cylinder which carries the cutters
or to the mandrill by means of a screw attached to a ring clasping the
cylinder or the mandrill which carries the cutter or cutters, and working
between collars formed thereon, or by an eccentric and connecting links
or link, or by other means. In cutting spiral grooves I may also use
dies, discs, or cutters set to the angle required, and as already described
for screw cutting. When a tube or bar is required to be cut off it is
secured within the said mandrill in a similar position to that already
described for tlie tube or bar to be tapped, and the said die not being
in gear with the said screw thread on the said hollow mandrill is set
into a continuous groove formed round the said mandrill at right angles
to its central axis, therefore the cutter or tool as it rotates will follow
its own groove, and being kept up to its work by means of a set screw
or other convenient method the operation of cutting off is performed.
And in order that my Invention may be more fully understood and
readily carried into effect, I will proceed to describe the same with the

page_text: aid of the accompanying Drawings, reference being had to the letters
and figures thereon marked, that is to say :-
Fig. I. represents an end or front elevation of the said machinery;
Fig. II. is a longitudinal vertical section of the same taken through
the line A, B; Fig. III. is a horizontal section thereof taken through the
line C, D; Fig. IV. is a vertical section (taken through the line A, B,)
of a part of the machine showing an arrangement for holding the said
dics which pass through the said external cylinder and take on to the
said mandrill for the purpose already described, and also for setting
and holding the said dies to any required angle; Fig. 5 is also a vertical
section (taken through the line A, B,) of a portion of the machine
shewing an arrangement for setting and holding the cutting tools to
any required angle to the work to be operated upon, and also for setting
the said cutting tools up to their work; Figs. 6 and 7 are likewise
vertical sections (taken through the line A, B,) of a part of the macliine
shewing it adapted for boring or internal tapping. In Fig. 6 the work
is shewn to revolve round the cutting tool, which is stationary, whilst
in Figure 7 the work is stationary while the tool revolves; and Figs. 8
and 9 are different views of a detached portion of my machine, to be
more fully described hereafter.
E (Figs. 1, 2, 3, 4, 5, 6, and 7) is a hollow tube or mandrill to which
the tube or bar F (Figs. 1, 2, and 3) to be operated upon is fixed in
the position shewn in Figs. 2 and 3) and held by means of the set
screws G, H, and here it will be obvious that the said tube or bar need
not extend the entire length of the said mandrill E, as shewn in Figs.
2 and 3, but may terminate anywhere between the said set screws G, H,
in which case it would be held solely by the set screws G; J, Figs. 2
and 3, are pattern screw threads cut or placed on the said mandrill E;
K is the external cylinder, which is fitted with recesses or mortices
formed therein to receive the cutting tools M, and which is also provided
with dies N (Fig. 2) and set screws O, one of which dies N having been
set into the pattern screw thread J on the mandrill E the external
cylinder K is caused to revolve by means of gearing P (Figs. 1 and 3),
and as it revolves the die N following the course of the pattern screw
thread J and the cutting tools M made to cut in both forward and
reverse motion, having been by means of the set screws R set up to
the tube or bar F, the screw is cut thereon, there being provided an
clongated pinion Q (Fig. 3) to allow of the longitudinal movement

page_text: of the external cylinder K. The dics N instead of being pointed may
be provided with discs to roll in the pattern screw threads J.
•
In a modification of the above-described method instead of having
guide screw threads cut or placed on the mandrill E, I pass through
the external cylinder K (Fig. 4) one or more chisel-pointed dies or
discs N, which take on to the said mandrill E, and may be set at any
required angle thereto by means of a plate or disc S provided with a
central angular opening T, which takes on to the corresponding angular
head U of the die or disc N, and will thus when turned turn the said
die or disc with it. This plate S is graduated or marked on its outer
perephery, so that the required angle of the said die or disc may readily
be determined upon. The said dies or discs N are kept in position by
means of the set screws O. In Fig. 5 is shewn an arrangement
whereby the cutting tool M. may be set to any required angle to the
substance F to be operated upon, and which is accomplished by means
of a cap or disc V provided with a point or projection W, which takes
into a recess formed on the side of the cutting tool M, and will thus
cause the said cutting tool to turn with it, when it is turned the said
cutting tool being held in the position required by means of a set screw.
The said cap or disc V is graduated or marked so that the required
angle of the cutting tool may be readily determined. For boring or
internal tapping I use a bar or tool holder F.(Fig. 6), held stationary
within the said hollow mandrill, while the substance Y to be bored or
internally tapped is secured to the said external cylinder and caused to
rotate therewith round the tool M, the necessary forward and backward
motion being imparted to the said external cylinder by either of the
methods already herein described; or the tool holder F (Fig. 7) may be
secured to the said external cylinder, and thereby caused to rotate
therewith, the set screws G, H, being fitted with caps, and made to act
as bearings for the said tool holder, while the substance Y to be operated
upon is fixed to a bed or frame a, to which the said hollow mandrill
is also fixed. This bed or frame a may also be used in connection with
the said hollow mandrill for the already described operation of boring
or tapping internally or externally, especially when a quantity of piping
or bars of short lengths are to be operated upon. It will be obvious
from Fig. 7 that the operation of boring or internal tapping may be
performed at either end of the machine. In cutting straight or spiral
grooves a reciprocatory motion is given to the said external cylinder by

page_text: throwing the wheel 6 (Figs. 8 and 9) in gear with the wheel c (Fig. 3),
which wheel c will impart motion to the said wheel b, and thus to the
bearing d, which being tapped to fit the screw e the said screw e will be
caused to work in or out thereof, according to the direction of motion
imparted to the said bearing d, and the said screw e being attached to
the said external cylinder by means of the ring f working between
collars 9 will impart to the said external cylinder a reciprocatory motion
regulated in speed by the pitch of the said screw e and the relative
diameters of the wheels b and c. For spiral grooves the necessary
rotatory motion is imparted to the said external cylinder by means of
guide screw threads on the said mandrill and dies in connection there-
with, or by chisel-pointed dies or discs set to the required angle, and
acting as herein-before described.
Having therefore thus fully described and ascertained the nature of
my said Invention, and the manner in which the same is or may be
performed, I would have it clearly understood that I do not confine
myself to the precise details herein described, as the same may be
somewhat modified without departing from the principles of my said
Invention; neither do I claim any of the mechanical parts herein
described, except when the same are employed in and for the purposes
of my said Invention; but what I do claim and desire to secure by
Letters Patent is, the mechanical arrangement and combination of the
several parts in the manner and for the purposes herein-before set forth
and described.
In witness whereof, I, the said Henry George Fairburn, have
hereunto set my hand and seal, this Sixteenth day of October,
the night luuundood and sist
In the presence of
HENRY GEORGE FAIRBURN. (L.S.)
JOHN W. GRAY,
27, Kempsford Road,
Kennington.