IMPROVEMENTS IN THE MANUFACTURE OF CORRUGATED TUBES SUITABLE FOR THE INTERNAL FLUES AND FIREBOXES OF STEAM BOILERS
Year: 1885

page_text: I, SAMSON Fox, of the Leeds Forge, New Wortley, Leeds, in the County of
York, Engineer and Ironmaster, do hereby declare the nature of my said invention
for "IMPROVEMENTS IN THE MANUFACTURE OF CORRUGATED TUBES SUITABLE FOR
THE INTERNAL FLUES AND FIREBOXES OF STEAM BOILERS and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-
"
My invention has reference to the manufacture of corrugated tubes suitable for
use as internal flues of steam boilers. Such flues are now made under former
Patents granted to me No 1097, dated March 19, 1877.-N° 2530, dated June 30,
1877, No 994, dated March 12, 1878, and No 219, dated January 16, 1882, by
first bending and welding the plate to a tubular form and afterwards corrugating
the welded tube by means of dies or corrugating rolls.
The object of my present invention is to produce corrugated tubes that will offer
like advantages in use to those referred to above, but which may be produced more
cheaply For this purpose according to this invention I make a corrugated tube as
follows, that is to say:-Sheet or plate metal such as mild steel, is bent to the
tubular form and by temporary means held in that form, and whilst so held, the
tubular plate is corrugated, or has formed in it undulations alternately at opposite
sides of the plate and running around the tube, and extending almost but not quite
to the longitudinal joint which is subsequently completed by rivetting, welding, or
brazing, in such a form as to increase the section of metal or thickness of the tube
at the joint (except at the ends) and constitute a longitudinal strengthening rib,
ridge or part of extra strength, such as will compensate for the absence of corru-
gations or alternate undulations at this part of the tube.
And in order to enable such tubes to be corrugated by dies or rolls such as
described in the Specifications of former Patents granted to me, No 1097, dated
March 19, 1877, No 2530, dated June 30, 1877, and No 219, dated January 16,
1882, I provide in the rolls, grooves such as will receive without pressing the
overlapping or juxtaposed flanged or other edges of the plates, so that the corru-
gations may be formed in an annular sense around a tube from one side to the
other of, but not across the longitudinal joint.

page_text: In carrying out my invention in practice, a flue tube joint may be made by
turning a portion of the two edges of the metallic plate intended to form the joint,
outward, either before or after bending such plate to the tubular form, these out-
wardly turned edges being brought together so that the plane of contact thereof is
radial to the axis of the tube.
These parts I secure together by a few temporary rivets or bolts, I next heat
them to a state suitable for welding, which I perform either by specially arranged
rolls or by hammering. Fig. 1. Sheet 1. is an end view of a tube with a projecting
joint A, as above described. Figs 2 and 3, shew the same in end and side views
when corrugated.
When making such a joint by rolling, I use a pair of rolls for pressing together
and welding the flanges. The said rolls may either be stationary, the tube being
caused to travel with the heated joint between them, or the tube may be stationary
and the rolls be caused to travel, I prefer the former method as shewn in Fig. 1*,
Sheet. 2. a, a, are the rolls suitably mounted and driven, b, is the tube mounted
upon the carriage c, or in other convenient manner, with the projections A, at
a welding heat between the rolls a, and capable of moving endwise as required.
Where for the purpose of welding the said joint, a steam hammer is used, such as
referred to in the Specification of. Letters Patent granted to me N° 994 dated the
12th day of March 1878. the tube may be stationary during the welding of the
joint, or if preferred the hammer may be stationary and the tube be caused to
travel. Fig 2*, Sheet 2, shews in end view a tube undergoing the process of
welding by hammering, b, is the tube mounted as above referred to, on a carriage c,
-d, the anvil, e, the hammer. The joint may be formed by turning two edges of
the metallic plate outward in a curvilinear form, so that the inner edges or
angles A', of the partially formed tube, meet or touch each other as shewn in
Fig. 4, Sheet 1.
These outwardly turned edges are next brought to a welding heat, placed upon
an overhanging anvil and subjected to the action of a hammer suitably formed for
welding the same and producing an angular or projecting ridge or projection along
the tube as shewn in Fig. 5, Sheet. 1.
Referring to Fig. 3*, on sheet 2, of the drawings, d', is an overhanging anvil, and
e, a movable steam hammer, the head of which is suitably formed at f, for imparting
to A', the desired shape to form the projecting ridge along the joint as shewn in its
finished form at g. in Fig 4*, Sheet 2.-Fig. 6, sheet 1, shews the tube when corru-
gated, the corrugations terminating on each side of and near to the ridged joint g,
Fig. 5. Sheet 1. The tube can be made with an ordinary overlapped joint as at
Fig. 7. Sheet 1. small rivets being applied temporarily. This tube is corrugated as
shewn in Fig. 8, Sheet 1. after which the small rivets are removed, the rivet holes
having in some cases become somewhat distorted by the action of corrugating,
I reamer them out to the required size for the final rivets which are then put in
and the joint finished.-When an ordinary overlapped and rivetted joint is used, no
special machinery is required, except a provision in the corrugating rolls for the
reception of the joint and as liereinafter described.
Comparatively thin tubes can be corrugated by blocking, by the use of a hollow
box or cylinder and a compound blocking piece. Figs. 9 and 10, Sheet 1. such as
is described in the Specification of my beforementioned Patent No 2530, dated
June 30th 1877, and in order to admit the projecting part or parts of the joint,
I provide suitable grooves or spaces B. B. (Fig. 9.) in the said hollow box and com-
pound blocking piece so that the corrugating may be effected without injury to the
joint. Having formed the plain tube, I heat it to a suitable degree and subject it,
if thin, to the action of the just described blocking apparatus.-Thicker tubes
I treat in a corrugating rolling mill such as described in the Specifications of the
before mentioned Letters Patent N° 2530, dated June 30th 1877, and N° 219, dated
January 16th 1882. In these rolling mills I provide the rolls, each with a longi-
tudinal groove or channel, so arranged that these grooves or channels shall be

page_text: After
opposite to each other when the rolls are in position to start, thus forming between
the two rolls a space for the reception of the projecting joint of the tube.
the tube has been placed with its joint in the said space, the rolls are caused to
mutually approach, or one is moved towards the other and then there is imparted
to them a forward and backward motion, somewhat less than a complete rotation,
until the required corrugations are perfectly formed in the tube under treatment,
except at that portion constituting the combined joint and longitudinal strengthen-
ing part. Fig. 5*, Sheet, 2, of the drawings, shows a tube b, in position between the
two rolls, with its projecting joint A, in the groove or space ¹, of the lower roll h.
-, is the groove or space in the upper roll i-In corrugating a tube with an
ordinary rivetted joint, the spaces i¹, and h, of the rolls receive such joint as shewn
in end view Fig. 6*, Sheet 2, and in longitudinal section in Fig. 7*, sheet 2, and
the operation of corrugating proceeds as above described in the case of a tube with
an externally projecting joint.
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. A metallic tube having corrugations extending almost entirely around it, but
not quite, and having between the extremities of such corrugations a longitudinal
joint so formed as to present in section a ridge projection or increased thickness or
depth of metal thereby increasing the strength of the tube to compensate for
absence of corrugations across this part (the joint) of the tube substantially as
described.
2. The manufacture of tubes such as referred to in claim 1. by making a joint in
the manner described with reference to Figs. 1. 2. and 3. by rolling or hammering,
and forming corrugations around the tube except at the joint, substantially as
described.
3. In the manufacture of tubes such as referred to in claim 1, making the joint
as described with reference to Figs 4. 5. 6. 3* and 4* of the drawings.
4. The use in the manufacture of tubes such as referred to in claim 1. of corru-
gating rolls formed with longitudinal grooves or channels to receive the enlarged
part or joint of the tube during the corrugating process as described with reference
to Figs, 5, and 6*, of the drawings.
5. The use in the manufacture of tubes such as referred to in claim 1. of a box or
cylinder and blocking piece or pieces formed with grooves or channels to receive the
longitudinal joint or enlargement of the tube during the corrugating process as
described with reference to Figs. 9, and 10, of the drawings.
Dated this 4th day of February 1885.
Witness,
T. E. CRAVEN, C.E.,
Fel. Inst. Patent Agents,
24, Victoria Chambers, Leeds.
SAMSON FOX.