IMPROVEMENTS IN THE MANUFACTURE OF METAL TUBING
Year: 1869

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," Southampton Buildings, London, Consulting
Engineer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF METAL TUBING." - A communication from abroad by Stephen
Paschall Morris Tasker, of Philadelphia, Pennsylvania, United
States of America.
Sealed the 11th February 1870, and dated the 24th December 1869.
COMPLETE SPECIFICATION filed by the said William Robert Lake at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 24th December 1869, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," Southampton
Buildings, London, Consulting Engineer, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF METAL TUBING," and have petitioned Her Majesty
to grant unto me, my executors, administrators, and assigns, Her Royal

page_text: Letters Patent for the same, and have made solemn Declaration that it
has been communicated to me from abroad by Stephen Paschall Morris
Tasker, of Philadelphia, Pennsylvania, United States of America.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement :-
In all other machines for making wrought metal welded tubes only
one pair of rolls, or a series of two or more pairs revolving in the same
plane are used, and consequently there is a tendency of the tubes to
spread as they pass between the rolls and form a fin at each side. To
overcome this difficulty I place one or more pairs of rolls at right angles
to and in advance of each pair first mentioned, whereby the fins are
pressed down, and the tubes are made of regular form.
Having thus stated the character of the Invention I will now proceed
to give a detailed description thereof, reference being had to the
accompanying Drawings making a part of this Specification, in which
Figure 1 is a front elevation of the said machine adapted to this method
of making wrought metal welded tubes; Figure 2 is a side clevation of the
same; Figure 3 is a top view; Figures 4, 5, 6, illustrate the progress of
forming the tubes according to this Invention. Like letters in all the
Figures indicate the same parts of the machine.
A is the standing frame of the machine; B, B, are pedestals or
bearings; C, C, are spur gear wheels; D, D, are mitre gear wheels.
The shaft E or the shaft F may either be used for the driving shaft.
G, G, are roll shafts; H, H, are rolls, and I is the mandrel, which is
supported at one end by a stand, not shown on the Drawings. The
pedestals or bearings of the several shafts are provided with adjustments,
not shown on the Drawings, by means of screws, wedges, or other
devices well known to mechanics, and the shafts have collars or steps
whereby the rolls can be set in the performance of the work. The outer
end of the mandrel I which is carried by the stand, not shown on the
Drawings, is so far distant from the rolls H, H, as to allow the finished
tube to pass over the mandrel, while the inner end of the mandrel which
shapes or forms the inside of the tube is placed in the openings made
by the grooves of the rolls. Where the mandrel lays in the grooves

page_text: there is a slight enlargement of the body at K, so so that in the process of
making the tube fits loosely on the rest of the mandrel after the grooves
are passed. The end of the mandrel is also separate from the stem at L,
so that it can be drawn from the tube after its completion by the
removal of the end K. This construction of mandrel is the one usually
adopted in rolling tubes with a mandrel as applied to tubes made with a
lap weld.
In making tubes with a butt weld, except where it is desirable to thin
the metal of the tube, no mandrel whatever is required or used. The
mode of operation of the machinery shown on the Drawings consists
merely in giving a rotary motion in one or the other direction to the driving
shaft E or F. It will be noticed that this arrangement places two pair
of rolls, one pair in advance of the other, with their axes in planes at
right angles, so that the bitė upon the metal between the first pair of
rolls and the mandrel, or the compression of the tube if no mandrel is
used, is quartering with the bite or compression which the second pair
of rolls will produce.
To give a full understanding of the nature of this Invention I will
state the action of the rolls upon the tube or skelp which forms the tube
where two or more rolls which converge about the tube having their
axes in the same plane are used with or without a mandrel in the
combination, being the usual method of manufacturing tubes. In this
explanation I will again refer to the Drawings, in which Figure 4 shows
a section of the unbent sheet of metal, technically known as a skelp,.
from which a tube is made. Figure 5 shows a section of the bent skelp.
as prepared for welding in the rolls; Figure 6 shows a section of the
unfinished tube when rolled by two rolls. The skelp has parallel edges.
which have been scarfed or bevelled away the entire length when lap.
welded tubes are to be made, but has square sound edges when butt
welded tubes are to be made. It is bent up from the form shown by
Figure 5 as a preliminary operation to the welding in the rolls at a heat
much below the welding heat. It is then permitted to cool and cast off
the scale or film of oxide which has been formed by the exposure of the
metal at the bending heat to the air.
To weld on the bending heat or bend on the welding heat has been
found impracticable, although such schemes have been proposed and
patented. The surfaces to be welded must be brought into contiguity
free from scale. Contact with the air or with cold iron will reduce the

page_text: temperature of the metal below that at which the scale will fuse away,
and the weld will be unsound, if not entirely defective. It is even
impossible to save the heat of bending by replacing the skelp when bent
in the welding furnace, as the scale formed by exposure then melts off,
and forming a flux for the bottom of the furnace not only destroys the
furnace, but gathers as a glass on the sides of the skelp, forming lumps
which make indentations on the tube when passing the rolls.
The form shown in Figure 5 is that of a loose scroll with the edges
overlapping each other a little more than the width of the bevelling, or
generally about three times the thickness of the metal at the unwelded
joint (with thinned edges) to be compressed when at a welding heat to
the same thickness as the rest of the skelp or tube when finished. The
enlargement K of the cylindrical mandrel, where the rolls act on the
tube, exactly fills the skelp. The grooves in the rolls for about one
hundred and twenty or to one hundred and fifty degrees are concentric
with the mandrel, and allow the same space for the metal that the tube
demands for its thickness all around when finished; the remainder of
the grooves, the side, so to speak, is opened out to allow the iron to
spread, while the corners of the grooves are rounded so that they shall
not mark or cut the tube as it passes through the rolls and over the
mandrel. The entire space between the rolls and the mandrel is just as
much less than the section of the skelp when bent, as it is found
practically possible for the draught of the rolls to pull the skelp over
the mandrel without sticking. It follows that a section of the tube after
its first or welding heat is that shown on Figure 6, and can be compared to
that of a Roman capital letter O (supposing the hole to be circular), with
two ribs or fins formed partly by the corners of the grooves in the rolls,
and partly by a thin sheet sheet squeezing out on the faces of the rolls.
Great care is needed to enter the lap of the skelp into the rolls so that
the bite shall come upon it, and it is very desirable that the skelp should
not twist, as in this case a portion of the lap will come in the parting of
the rolls, when a sound weld is by no means so well insured. The
imperfect tube is then permitted to cool and cast off its scale for the
same reason that the bent skelp is cooled, and is then reheated and
again passed through the rolls, taking care to enter the thick sides, so
that the work will now come on them. The fins are either burned or
fused away in the furnace, or are so softened as to roll down and weld
to the body of the tube, and the tube will be of uniform thickness. In

page_text: this second rolling not so much work is put upon the iron between the
mandrel and the rolls, consequently little or no fin is formed. The same
difficulty of turning down is here encountered, and frequently a third
or fourth rolling is needed to get a sound or uniformly thick tube. It is
possible to make and finish tubes at one rolling if the inequality of
thickness referred to is not regarded, and if the fins be chipped, milled,
or pared away.
With inferior iron (the lower grades being softer when hot) the
grooves in the rolls can be made more nearly concentric than I have
desoribed, and the fin only is very objectionable. With three or four
rolls converging together, having their axes in the same planes, the
forms of the grooves can be made altogether concentric to the mandrel,
but the fins produced by the partings are not only more in number, but
they are more objectionable in size than with two rolls. With this
arrangement of three or four rolls it is nearly impossible to obliterate
the fins by re-rolling.
In rolling butt welded tubes without a mandrel the action of the tube
is very nearly as with the mandrel, except that some portion of the
effect is expended in making the hole or bore of the tube slightly oval.
In butt welded tubes the thickness of metal relative to the diameter is
necessarily so great that it acts as a mandrel to a considerable extent.
The improved method of welding, sizing, and smoothing wrought
metal tubes which I have invented offers the means whereby if any fin
or inequality of the thickness has been formed in the first pair of rolls
it is rolled down and obliterated by the second; or if the skelp has
twisted, so that the lap has not been brought under the bite of the first
pair of rolls, such portion is immediately acted upon by the second pair
of rolls, and the weld, the thickness, and the uniformity of the tube is
thus insured.
I am aware that four converging rolls or more than two rolls with
their axes in the same plane have been proposed and used in welding
and sizing tubes. I am aware that two pairs, or a series of pairs of rolls
in advance of each other with the axes of each pair in planes at right
angles, have been proposed for bending up metal forms, and in one or
more instances the combination of bending with welding by similar
series of rolls has been proposed. I am aware that a pair of rolls
combined with a pair of milling cutters rotating at right angles to the
rolls to remove the fins has been proposed, and that two pairs of rolls

page_text: with the axes of each pair at right angles, one pair in advance of the
other, have been proposed and used under the name of universal mills
for rolling sheet, band, or girder iron. I am also aware that series of
pairs of rolls in advance of each other, with axes of the following
pairs at right angles, have been proposed and used in rolling rods and
bars. I therefore do not claim any of these machines, nor the appli-
cation of them to the various processes mentioned; but I claim, the
method of manufacturing wrought metal welded tubing previously
prepared by bending, as herein-before described.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Twenty-fourth day of December,
in the year of our Lord One thousand eight hundred and sixty-
nine.
WILLIAM ROBERT LAKE. (L.S.)
Witness,
H. J. GEDGE,
Clerk to Messrs. Haseltine, Lake, & Co.,
8, Southampton Buildings,
London.