Year: 1886

page_text: Date of Application, 19th Apr., 1886..
Complete Left, 17th Jan., 1887.
Complete Accepted, 18th Feb., 188
DEAN I TERRE DERVE, OF Givors, renone, m the repune of France, Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to the manufacture of tubes with ribs projecting outwardly or
inwardly for the purpose of increasing the power of transmitting heat or cold of tubes,
applicable for boilers, condensers, refrigerators, and other purposes.
:
For making a drawn ribbed tube of brass or alloy, I cast a tubular ingot having
ribs throughout the greater part of its length but having its end strong and solid to
be laid hold of by the gripper of the draw bench, but small enough to pass through
the die or triblet. In order to maintain the strength of this end, it may, from time
to time during the drawing process, be annealed and hammered, the hammering
reducing it to suit the dimensions of the smaller dies employed. By drawing the
tube through successively smaller dies, diminishing very gradually, it is lengthened and
shaped. Li is of importance that the ribs originally cast on the ingot shall themselves
contain sufficient metal to form the finished ribs so that no material has to be drawn
from the circumference of the tube. It is also of advantage before drawing the tube
to insert into the ingot a mandril of the shape of the interior, but longer and to
hammer or press the ingot, lengthening it somewhat and solidifying it. The ribs of
the mandril are necessarily made slightly tapered so that it can be readily withdrawn.
To facilitate withdrawal the tube may be expanded by heat or by being passed
between grooved rollers. It is not necessary in all cases to make the ingot with
ribs in the first instance. A ribbed copper tube may be made as follows: I take
a round bar with a hole through it lengthwise into which I introduce the ribbed
mandril. I hammer, press or roll the tube until it becomes shaped to the mandril
and then draw it through dies. In order to strengthen the end by which the tube
is gripped cast metal in it, running enough through the mould io thoroughly
heat that part of the tube and weld the fresh metal to it. Instead of making the
tube from a bar, it may be made by punch drawing from a disc of metal, the punches
and dies being so formed as to leave the closed end strong for afterwards drawing the
tube with a mandril in it. Instead of using a plain disc, a disc thickened in the
middle and having radiating ribs may be treated in this way,

page_text: Instead of drawing the ribbed tubes through dies, they may in many cases be drawn
by rollers and they may be, as above described, drawn from ingots or discs without
joints, or from tubular blanks made from sheet bent round and soldered or welded
along the joint, and these sheets may themselves be ribbed.
When the ribs are not straight but helical, the mandril and tube are caused to revolve
while they travel through the dies.
Ribs may be formed by folding the sheet, constituting the metal of the tube in
pleats inwards or outwards or both inwards and outwards. In order to make such a
tube with plain ends so that they can be readily secured in tube plates, I pleat the
sheet along the greater part of its length leaving parts at the end flat, those paris
being somewhat narrower than the part that has to be pleated. When the sheet thus
prepared is folded into tube form with its joint soldered, the ends are plain, the ribs
stopping short and dying out at some distance from the ends. The folding of the
sheet in pleats may be effected by rollers or by pressure of successive dies, the first
V shaped to make corresponding folds and the others arranged to squeeze these folds
into close pleats. In each pleat there may be introduced a strip of metal more or less
wide forming a rib projecting opposite to the pleat itself. Instead of making tubes
with pleat ribs from the sheet, they may be made from jointless tubes drawn through
taper dies so shaped as gradually to raise or depress the metal of the tube into pleats
and to close these.
Ribbed tubes may be made of a number of cylindrical segments jointed together,
each segment having at its one edge a pleat in which is engaged the bent edge of the
next segment.
Copper which can be easily treated by rolling, drawing and otherwise is well adapted
for making ribbed tubes but is too soft for many purposes. In order to give such
tubes greater stiffness I convert them partially into brass by galvanising them with
zine and heating once or more so that the zinc penetrates the pores of the copper forming
an alloy.
ABEL & IMRAY,
28, Southampton Buildings, London, W.C.,
Agents for the Application.

page_text: I, JEAN PIERRE SERVE, of Givore, Rhone in the Republic of France, Engineer,
do hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following state-
ment:-
My invention relates to the manufacture of tubes with ribs projecting outwardly or
inwardly for the purpose of increasing the power of transmitting heat or cold, as, for
instance, when tubes are used in boilers, condensers, refrigerators and other apparatus,
in which applications it is desirable to extend as much as possible the surfaces through
which heat is to he transmitted. I will describe the metliods of manufacturing ribbed
tubes according to my invention referring to the accompanying drawings. Figs. 1, 2,
3, 4, 5, 6 and 7 are transverse sections of some of the chief kinds of ribbed tubes.
Fig. 8 is a side view of an ingot for an internally ribbed tube, a transverse section of
which on the line abis shewn to an enlarged scale by Fig. 9. A transverse section
of the internal mandril is shown by Fig. 10, and Fig. 11 is a transverse section of the
tube produced from the ingot of which Fig. 9 represents the section. It is to be
understood that in the several forms of tubes to be described, the number and shape
of the ribs may be varied.
In manufacturing such a tube as is shewn full size by Fig. 11 an ingot such as is
shewn by Figs. 8 and 9 is cast in brass or other suitable metal or alloy with a central
hollow open at the one end but closed at the other, and with internal ribs extending
along the hollow. The closed end of the ingot is suited for being taken hold of in
the operation of drawing, and in order to have it sound and strong it is reduced to a
size to pass through the die preferably by repeated hammerings with intermediate
annealings and picklings. The drawing of the tubes is preferably effected by a large
number of successive operations each reducing it but slightly in diameter, a mandril
approximately of the form shewn in Fig. 10 and of size and width of ribs suited to
cach drawing operation, being placed inside of it. As an example of the rate of
drawing, an ingot of 115 millimetres diameter may be reduced about 2 millimetres at
cach drawing down to a tube 50 millimetres in diameter. In determining the form
of the ingot and of the mandrils, care should be taken that in drawing the ribs no
metal should be taken for them from the circumference of the tube, each rib should in
the first instance have sufficient metal in itself to give it the finished length. At the
same time, with care and trouble, it is possible to draw tubes with ribs receiving part
of their material from the circumference.
Before drawing the tube, the mandril fitting its interior is introduced and the ingot is
compressed between dies or rollers. The mandril, which is held by a rod extending back
along the draw bench need not be of great length, not more than 7 or 8 centimetres
with its entering ends sloped off to facilitate the drawing of the metal along it. In
order to get the finished tube straight, the last mandril should extend its whole
length, and in order to take the tube off it, it may be expanded a little by heat or by

page_text: various ways.
the pressure of grooved rollers. The ingots may be cast in any known way, more or
less near to the form and dimensions of the finished tube, and therefore requiring less
or more drawing. Instead of casting ingois, blanks for tubes may be formed in
Thus for making a copper tube, a round bar is bored lengthwise, and
a ribbed mandril being introduced into the bore, the bar is hammered, pressed or
rolled until ribs are formed to fit the mandril, and then the tube is drawn. In order
to strengthen the end which is taken hold of for drawing, the hollow blank is heated
and filled with sand or loam up nearly to the end, and hot melted metal is run into the
empty end and allowed to overflow heating the blank until there is a complete union
with the new metal which may be the same as that of the blank or a suitable alloy..
Thus the end to be taken hold of is rendered sound and solid.
For an externally ribbed tube the blank may obviously be prepared by planing out
the spaces between the ribs.
Certain metals such as copper or its malleable and ductile alloys. can be punch
drawn to form blanks for ribbed tubes from dises, which may be in the first instance
thickened in the middle or may have rudimentary ribs on them, cast or formed by.
pressing the dises in dies, thus closing the pores of the metal before the punch
drawing to form the blanks for the draw bench. The rudimentary ribs may be formed
on both sides of the disc, but when the tube is intended to have only one set of ribs,
either inside or outside, the doubly ribbed disc is sawn into two thicknesses before
being punch drawn.
For many purposes, internally ribbed tubes may be formed by rolling them either hot
or cold on ribbed mandrils, with intermediate annealings when they are rolled cold.
Instead of preparing ingots or blanks as above described for solid drawn or rolled
tubes, they may be prepared for tubes having welded, brazed or soldered joints from
ribbed plates bent round, the ribbing of the plates being effected by gradual drawing
or rolling.
In preparing ingois for helically ribbed tubes, the ribs of the ingot, instead of being
straight, are helically curved, and in like manner the ribs of the discs for punch
drawing are of volute curvature. In drawing such tubes the mandril is permitted or
caused to revolve as the blank advances along it.
Internally ribbed tubes may be formed as shewn by Fig. 6 by making longitudinal
folds in a plate of metal in the following manner. The plate is first longitudinally
corrugated between rollers, either forming the several corrugations by one operation,
or, by successive operations, one at a time. The corrugated plate being then laid on
a table with bars laid between the corrugations, the whole is subjected to lateral
pressure closing up the corrugations. In order to close them more completely, the
bars laid between them may be of considerable length and slightly tapering in width.
After they have been pressed up laterally, the bars are drawn lengthwise and as their
increasing width passes between the corrugations they squeeze their sides closely
together. The closed corrugations may then be soldered or bronzed and the plate
being bent round is soldered or bronzed along its joint. Obviously the ribs formed
thus may be internal or external according as the plate is bent into tube form in the
one direction or the other.
It is often desirable to have tubes that are ribbed along the principal part of their
length, without ribs at their ends so that they may be properly fixed in tube plates.
In forming such tubes, the plate that is to be corrugated is made narrower at the
ends than elsewhere, the width of the end being just equivalent to the circumference
of the tube. The corrugations are then formed, one at a time, by laterally pressing
the plate between two dies, or by passing it between grooved rollers, the upper one of
which is raised to pass without corrugating the flat parts of the plate, and is lowered
to form the corrugations. In tubes having ribs formed by corrugations of plates as
above described, the corrugations may be filled with metal strips, and these strips
may project so as to form ribs on the side opposite to those formed by the corruga-
tions as shewn in Fig. 4.
Ribs may be formed by corrugating and folding the metal of the tube itself, the
circumference being in the first instance large enough to allow sufficient metal to form

page_text: the folls. Such a tube having been drawn through tapering toothed dies which
gradually reduce its diameter and shape the ribs, is enclosed in a strong casing and
then a taper mandril grooved to suit the ribs is forced through the tube to close
the folds which constitute the ribs, which may then be soldered. The plate employed
for forming ribbed tubes by corrugation may be rolled with longitudinal bands of
different thicknesses, those parts that are corrugated to form the ribs being thinner
if desired than those which are to form parts of the circular circumference.
Ribs may be formed in tubes at the jointing together of several sections as shewn
in Fig. 7, where two sections are joined forming two ribs. The one section has its
edges longitudinally corrugated to receive in their hollows inwardly bent flanges at
the edges of the other section. When the one section is engaged with the other by
longitudinally sliding the one along the other, the corrugations are closed by pressure
witli a taper mandril as already described, and the joints may be soldered. Obviously
there may be a number of sections greater than two, united in a similar way.
Fig. 5 shews a tube with internal and external ribs formed by the folding of the
circumferential metal. The plate of which the tube is made is doubly corrugated,
that is, to say, with a hollow and a prominence at each line of corrugation, and the
folds are closed up by the lateral movement of bars interposed between the
prominences of the corrugations on each side of the plate.
Copper, which can be easily treated by rolling, drawing and otherwise, is well
adapted for making ribbed tubes, but for many purposes tubes so made are too soft.
In order to give them greater stiffness, I convert. them partially into brass by
galvanizing them with zine and then keeping them heated for a time sufficient for the
zine to penetrate the pores of the copper and form with it a species of alloy. The
galvanizing and heating may be repeated several times. The same result may be
obtained by keeping the tubes immersed for some time in the zinc bath, but in this
way a portion of the copper becomes dissolved and mixes with the fused metal in the
bath.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. The manufacture of ribbed tubes without joints by drawing them from ingots or
blanks having ribs of suitable substance through successive dies over successive
mandrils, substantially as described.
2. The manufacture of ribbed tubes with welded, brazed or soldered joints by
longitudinally corrugating plates and closing the corrugations to form ribs then
bending the plates thus ribbed to circular form, uniting their edges and farther closing
and shaping the ribs, substantially as described.
3. Galvanizing ribbed tubes made of copper in the manner and for the purpose
herein set forth.
ABEL & IMRAY,
Agents for the Applicant.