IMPROVEMENTS IN APPARATUS FOR CUTTING SCREWS UPON WROUGHT IRON AND OTHER METAL PIPES, TUBES, AND CYLINDERS
Year: 1879

page_text: LETTERS PATENT to James Mac Kenzie, of the Firm of Strode and Company,
Engineers and Gas Fitters, of 48, Osnaburgh Street, Regent's Park, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN APPARATUS FOR
CUTTING SCREWS UPON WROUGHT IRON AND OTHER METAL PIPES, TUBES,
AND CYLINDERS."
Sealed the 2nd December 1879, and dated the 2nd September 1879.
PROVISIONAL SPECIFICATION left by the said James Mac Kenzie at the
Office of the Commissioners of Patents on the 2nd September 1879.
"
JAMES MAC KENZIE, of the Firm of Strode and Company, Engineers and Gas Fitters,
IMPROVE
of 48, Osnaburgh Street, Regent's Park, in the County of Middlesex.
MENTS IN APPARATUS FOR CUTTING SCREWS UPON WROUGHT IRON AND OTHER
METAL PIPES, TUBES, AND CYLINDERS."
This Invention relates to improvements in apparatus for cutting screws upon
wrought iron and other metal pipes, tubes, cylinders, shafts, and rods, whereby the
operation of cutting screws thereon is greatly simplified, the apparatus being also
very portable.
Heretofore screw threads have been cut on the ends of pipes (to form joints for
connecting them together) by means of ordinary stocks and dies, and when the
pipes are of comparatively large diameter considerable power is required for cutting
such screws, the apparatus employed being heavy and fixed or stationary, whereas
my improved apparatus can be readily removed from place to place as required.
In carrying out my improvements the pipe on which a screw thread is to be cut
is fixed in any convenient manner in the centre of a tubular or cylindrical clamp or
holder. Upon a projecting part of the tubular holder a screw thread is cut on
which a screw nut or socket is mounted so as to travel to and fro thereon when
caused to revolve by suitable lever, arms, or otherwise. The travelling nut or
screw socket carries a tool holder and slide similar to the slide rest of a lathe, so
that the cutting tool can be readily moved towards and from the surface of the pipe
to be cut as the screw socket and cutter thereon rotates around it.

page_text: When the pipe is fixed in position the part on which the screw is to be cut is first
made true and smooth by means of a suitable cutter mounted on the tool holder
and rotating screw socket. The screw cutting tool is then fixed in the holder, being
formed so as to cut either one or more of the threads of the screw at the same time.
By setting up the cutter from time to time the screw thread can be cut to any
depth required, the pitch of the screw corresponding with that of the fixed screw
and screw socket which carries the tool holder and cutter.
The tool holder and cutter may be arranged to cut a screw thread on the inner
circumference of a pipe, tube, or cylinder, if desired.
In like manner a screw thread may be cut on the outer circumference of a rod or
shaft if required.
The arrangement of the apparatus may be considerably varied without departing
from the nature of my Invention, and in place of the screw socket and cutting tool
rotating around the pipe or cylinder to be cut the same may be fixed or stationary,
the other parts being arranged to rotate.

page_text: Figure 1 shows a vertical section; Figures 2 and 3 are side elevations, and Figure
4 a plan of apparatus arranged and constructed in accordance with my Invention
for cutting screws upon metal pipes or tubes.
In carrying out my improvements the pipe a on which a screw thread is to be
cut is fixed by set screws a¹, a¹, or in any other convenient manner in the centre of
a tubular or cylindrical clamp or holder b upon a projecting part b' of the tubular
holder b, a screw thread is cut on which a screw nut or socket c is mounted so as to
travel to and fro thereon when caused to revolve by suitable lever arms c' or
otherwise. The travelling nut or screw socket c carries a tool holder and slide c
similar to the slide rest of a lathe so that the cutting tool c³ can be readily moved
towards and from the surface of the pipe a to be cut, as the screw nut or socket c
and cutter thereon rotates around it.
When the pipe a (or it may be a rod or solid cylinder) is fixed in position the part
a on which the screw is to be cut is first made true and smooth by means of a
suitable cutter mounted on the tool holder c² and rotating screw nut or socket c.
The screw cutting tool is then fixed in the holder c³, being formed so as to cut
either one or more of the threads of the screw at the same time. By setting up the
cutter 3 from time to time the screw thread can be cut to any depth required, the
pitch of the screw corresponding with that of the fixed screw b¹ and screw socket c
which carries the tool holder and cutter c³.
The tool holder and cutter may be arranged to cut a screw thread on the inner
circumference of a pipe, tube, or cylinder, if desired.
In like manner a screw thread may be cut on the outer circumference of a rod
or solid shaft, or cylinder if required.
The apparatus may be fixed in a vertical or horizontal position as convenience
may require, as illustrated by Figures 5 and 6.
It will be evident that the arrangement of the apparatus may be considerably
varied without departing from the nature of my Invention, and in place of the
screw socket and cutting tool rotating around the pipe or cylinder to be cut the
same may be fixed or stationary, the other parts being arranged to rotate.

page_text: Having thus described the nature of my Invention and the manner of performing
or carrying the same into practice I would remark that I do not claim any of the
mechanical parts separately which are well known and in common use, but what I
claim is
The improved arrangement and combination of portable apparatus for cutting
screws upon wrought iron and other metal pipes, tubes, and cylinders, in which a
travelling tool holder and screw cutting tool are caused to rotate around a pipe,
tube, or solid cylinder to cut a screw thread thereon, substantially in the manner
and for the purpose herein before described and represented in the Drawings
annexed.
In witness whereof, I, the said James Mackenzie, have hereunto set my hand
and seal, this Twenty sixth day of February, in the year of our Lord One
thousand eight hundred and eighty.