provements in and connected with the Manufacture of Steam Generator Shells, Cylinders, Furnaces, and other Hollow Articles.
Year: 1899

page_text: Date of Application, 23rd Nov., 1899
Complete Specification Left, 23rd Aug., 1900-Accepted, 17th Nov., 1900
PROVISIONAL DIUITIATION
Improvements in and connected with the Manufacture of Steam
Generator Shells, Cylinders, Furnaces, and other Hollow Articles.
I, BALFOUR FRASER MCTEAR, of Brook Cottage, Rainhill, in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention has reference to the manufacture of shells, flues, or cylinders of
steam generators, and other analogous articles.
even more;
In the ordinary way, the shells of steam generators are formed of plates curved
to the required shape and connected together by means of longitudinal and cir-
cumferential lines of rivets. It has been determined by eminent authorities that
the best system of rivetting weakens the plates one fourth, or
and that if the longitudinal seams could be avoided, an augmentation of pressure
to the extent of about 25 per cent., would be permissible with the same thickness
of shell plates. Prior, however, to the present time, it has been proposed to make
cylinders or rings of metal without joint, seam, or weld, by a rolling operation
from an ingot of steel, or from a bloom or mass of metal, similarly as in the roll-
ing of railway tyres. The proposed method of preparing the ingot or bloom for
the rolling operation, consisted in forming a hole in it by a steam hammer, and
placing it on a mandril, and then hammering it in a swage. It has also been
suggested to take a cast hollow cylinder ingot, and forge it to the right size. For
effecting the purposes of the present invention, these proposals are practically
useless, or offer very considerable difficulties in the manufacture. To treat a
block of metal of a size and weight suitable for making boiler shells or flues in
the manner proposed, it is hardly, if at all, practicable, and in any event extremely
difficult; and to roll, as has been proposed, a number of shells or flues direct
from prepared ingots or blooms, to an exact diameter and thickness, such as are
required in practice, is next to impossible.
According to this invention, the objections and difficulties above referred to
are overcome; and the manufacture of seamless boiler shells, cylinders, or similar
hollow articles, in an expeditious, inexpensive and satisfactory manner is carried
out. The following is the method or process by which the ends referred to are
attained:-
The metal from which the shell or cylinder is to be made is in the form of an
ingot or bloom, hammered or cast to any desired shape in cross section, and
having the requisite mass or weight to produce a shell or cylinder of the required
size;
and this ingot or bloom, in a white hot or glowing state, is placed in a die,
and pierced (say by hydraulic pressure) longitudinally, while held in this die,
the piercing being effected by a conical or bulbous pointed mandril or tool. The
effect of this action, besides the formation of the immature hollow cylinder or
shell, etcetera, is to compress and condense the metal, and also in some cases-
to elongate the body to the length required. Thus the quality of the metal is
improved, as the pressure caused by the piercing closes up all holes and porous
places which may exist in the ingot or bloom, and generally compresses the metal.

page_text: The hole will be of considerable size, and is effected by one pass of the mandril
of the size required, or by consecutive passes of mandrils of different sizes.
The immature cylinder or article, after removal from the die in which it is
pierced, is, without reheating, or after being re-heated, rolled out by suitable
inside and outside rollers to a larger diameter than that which the finished ring
is to be, but of the exact thickness of ring plate required (this excess of size
being allowed for in the ingot or bloom, by employing a bloom or ingot of greater
weight than the finished article); and then this extra metal, in the form of
excess of diameter, is reduced and converted into extra length by rolling on the
outside, i.e. externally, by a plurality of rolls arranged at different parts around
it, the thickness of the plate remaining the same. Or, the immature shell is
rolled out to the external diameter required, with a slight excess of thickness of
plate, and this excess of thickness is rolled out, and converted to length of shell,
by rolling it between rollers arranged round the shell or cylinder on the outside
and inside. In the latter case the outside rolls serve to form a support to the
outside surface, or a roller cage for it; while the inside is operated upon by
small round reducing rollers which are moved longitudinally along it. In some
cases, when the latter method is used, the cylinder may first be made larger
than the finished diameter, but of the correct thickness of plate, and
reduced by this latter method, and the extra diameter converted into length. Or,
partly one and partly the other mode and operation may be employed.
In order to be useful for employment in the manufacture of steam generator
shells, furnace flues, and the like, it is necessary that the shells or cylinders of
which they are comprised be quite accurate as to diameter of the cylinder, and
also as to the thickness of the plate; and these two conditions and characteristics
are readily accomplished by the method or process of manufacture or improve-
ments according to my invention.
With regard to the manufacture of cylinders or equivalent bodies, as described,
accurate both as to diameter, and also thickness of plate, one machine, or arrange-
ment of machinery, by which this is carried out advantageously consists as
follows:-
A bed having rollers on each side of, and parallel with its longitudinal centre,
supports the cylindrical body having an excess of diameter, which is to be reduced;
and these supporting rollers will be provided in duplicate on either side of the
centre of a frame carrying the outside reducing rollers; and they are capable of
adjustment, by supporting them at each end in sliding bearings capable of being
moved up and down, simultaneously, through adjusting shafts and tooth wheels.
This arrangement of rollers provides a roller bed on which the cylinder will
revolve readily, and also be moved longitudinally; and the rollers may consist
of a plurality of small rollers mounted on common shafts. The rollers which
act on the outside of the shell or cylinder are in multiple, arranged round the
housing or frame, and comparatively closely together, the axes of their supports
being radial to the centre of the housing. The frame or housing is circular, and
the rollers will be supported in sliding or adjustable supports carried in the said
frame, and capable of being moved out or in, simultaneously, or otherwise, and
disposed in skew arrangement. Some, say two or three, of these skew rollers
will be driven from an engine; and they would be adapted to revolve at a high
speed, so that. the rate of reduction, while small per revolution, can be rapid, and
the weight and strength of parts kept as small as possible. These skew rollers
may be operated by shafting, arranged at each side, mounted in adjustable bear-
ings at each end, and adapted to move them inwards and outwards; and they are
moved simultaneously through chain or other suitable gearing, which may be
operated by the same actuating means as that for the circumferential skew rollers.
An universal joint may connect the ends of these shafts with the driving shafts
of the engine; and this engine may, be disposed at the end of the machine, and
drive them the shafts-through increasing gear, namely, tooth wheels.
In another type of machine for effecting the purposes of this invention, a

page_text: number of parallel long rollers are employed, arranged in circular arrangement,
and supported from either end by adjustable or sliding bearings, carried in circular
housings or frames. The bearings will be moved outwards and inwards in guides
in a radial direction; and the machine will be thus adapted to take shells or
cylinders of different diameters, as in the former case. The cylinder or shell
to be operated upon is placed in the cage formed by these rollers, and it is rotated
by them, two or more of the said rollers being driven by an engine, similarly as
the external rollers above described.
Centrally, within this housing and cage, there is another set of small skew
rollers, carried in a suitable carrier, and mounted on a strong central shaft, sup-
ported in bearings outside each end of the housings. This shaft and rollers are
moved longitudinally through the cylinder or shell being rolled, and they operate
on the interior of the surface of the shell, as hereafter described.
The shaft supporting the inside skew rollers is hollow, and the bearings which
support it are adapted to slide longitudinally on a frame, say by racks and
pinions; and the shaft itself is adapted to be moved longitudinally by a hydraulic
ram at one end, acting upon such end through side connecting rods.
The internal rollers are mounted in bearings supported by the carrier; and
these bearings are adapted to be moved inwards and outwards by a hollow conical
slide inside the tube and carrier, with which the said roller bearings work or
engage; and this conical slide being moved longitudinally in the tube and carrier.
by a screwed rod and an actuating wheel at the end of the tube, the rollers will
be forced out, or drawn in, according to which direction the slide is moved.
Normally, the inside skew rollers, and the external rollers, will be in the same
radial lines, and are held in this position; but when it is desired for certain
operations to set the inside rollers outwards, when the tube is in place, the
shaft is adapted to be rotated a partial revolution, to bring the inner rollers
between the outer rollers; but normally the only motion the slide shaft and the
internal roller carriers have, is a longitudinal one.
In one mode of operating, the cylinder or shell to be operated upon is, in the
prior rolling out action-that is, the rolling action proper,--made larger in dia-
meter than that required. Then the cylinder is placed in position in the roller
cage or cradle, and the outside rollers act upon it, and reduce it in diameter to
that required, and the inside rollers being set to produce the internal diameter
required, they are moved to and fro longitudinally by their carrier
shaft, and convert the extra diameter of the shell into length. "Or, as a modifi-
cation, if the external diameter of the shell be that exactly required, and the
plate have an excess of thickness, then this excess of thickness is rolled off, and
converted into length, by operating upon it by the internal skew rollers, which
are passed longitudinally through it.
With regard to the machines herein described, these are not restricted under
this invention to the use solely for operating upon the particular cylindrical
articles specified; since they may be wholly or partly employed in connection
with the manufacture of similar hollow bodies or articles, otherwise made than
as described, whether of plain, corrugated or similar form.

page_text: Improvements in and connected with the Manufacture of Steam
Generator Shells, Cylinders, Furnaces, and other Hollow Articles.
I, BALFOUR FRASER MCTEAR, of Brook Cottage, Rainhill, in the County of
Lancaster, 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 statement:-
My invention has reference to the manufacture of shells, flues, or cylinders of
steam generators, and other analogous articles.
In the ordinary way, the shells of steam generators are formed of plates curved
to the required shape and connected together by means of longitudinal and cir-
cumferential lines of rivets. It has been determined by eminent authorities that
the best system of rivetting in use weakens the plates one fourth, or even more;
and that if the longitudinal seams could be avoided, an augmentation of pressure
to the extent of about 25 per cent., would be permissible with the same thickness
of shell plates. Prior, however, to the present time, it has been proposed to make
cylinders or rings of metal without joint, seam, or weld, by a rolling operation
from an ingot of steel, or from a bloom or mass of metal, similarly as in the roll-
ing of railway tyres. The proposed method of preparing the ingot or bloom for
the rolling operation, consisted in forming a hole in it by a steam hammer, and
placing it on a mandril, and then hammering it in a swage. It has also been
suggested to take a cast hollow cylinder ingot, and forge it to the right size. For
effecting the purposes of the present invention, these proposals are practically
useless, or offer very considerable difficulties in the manufacture. To treat a
block of metal of a size and weight suitable for making boiler shells or flues in
the manner proposed, is hardly, if at all, practicable, and in any event extremely
difficult; and to roll, as has been proposes, a number of shells or flues direct
from prepared ingots or blooms, to an exact diameter and thickness, such as are
required in practice, is next to impossible.
According to this invention, the objections and difficulties above referred to
are overcome; and the manufacture of seamless boiler shells, cylinders, or similar
hollow articles, in an expeditious, inexpensive, and satisfactory manner is carried
out. The following is the method or process by which the ends referred to are
attained:-
The metal from which the shell or cylinder is to be made is in the form of an
ingot or bloom, hammered or cast to any desired shape in cross section, and
having the requisite mass or weight to produce a shell or cylinder of the required
size, and this ingot or bloom, in a white hot or glowing state, is placed in a die,
and pierced (say by hydraulic pressure) longitudinally, while held in this die;
the piercing being effected by a conical or bulbous pointed mandril or tool. The
effect of this action, besides the formation of the immature hollow cylinder or
shell, etcetera, is to compress and condense the metal, and also-in some cases-
to elongate the body to the length required. Thus the quality of the metal is
improved, as the pressure caused by the piercing closes up all holes and porous
places which may exist in the ingot or bloom, and generally compresses the metal.
The hole will be of considerable size, and is effected by one pass of the mandril
of the size required, or by consecutive passes of mandrils of different sizes.
The immature cylinder or article, after removal from the die in which it is
pierced, is, without reheating, or after being re-heated, rolled out by suitable
inside and outside rollers to a larger diameter than that which the finished ring
is to be, but of the exact thickness of ring plate required (this excess of size
گلہ

page_text: being allowed for in the ingot or bloom, by employing a bloom or ingot of greater
weight than the finished article); and then this extra metal, in the form of
excess of diameter, is reduced and converted into extra length by rolling on the
outside, i.e. externally, by a plurality of rolls arranged at different parts around
it, the thickness of the plate remaining the same. Or, the immature shell is
rolled out to the external diameter required, with a slight excess of thickness of
plate, and this excess of thickness is rolled out, and converted to length of shell,
by rolling it between rollers arranged round the shell or cylinder on the outside
and inside. In the latter case the outside rolls serve to form a support to the
outside surface, or a roller cage for it; while the inside is operated upon by
small round reducing rollers which are moved longitudinally along it. In some
cases, when the latter method is used, the cylinder may first be made larger
than the finished diameter, but of the correct thickness of plate required, and
reduced by this latter method. Or, partly one and partly the other mode of.
operation may be employed. Or, the diameter may be greater than that finally
required and of thinner metal, and then reduced in diameter and thickened in
the plate by outside rolling.
In order to be useful for employment in the manufacture of steam generator
shells, furnace flues, and the like, it is necessary that the shells or cylinders of
which they are comprised he quite accurate as to diameter of the cylinder, and
also as to the thickness of the plate; and these two conditions and characteristics
are readily accomplished by the method or process of manufacture or improve-
ments according to my invention.
Machinery by which the manufacture of large cylinders or equivalent bodies,
as described, accurate both as to diameter, and also thickness of plate, can be
carried out advantageously, is illustrated in the annexed drawings. In these,
Figure 1 is a side elevation partly in section, Figure 2 an end view partly in
section, and Figure 3 a plan illustrating one modification.
Figure 4 is a side elvation, half in section, and Figure 5 an end view partly
in section, shewing another modification of the machine.
Like letters and figures of reference are used to denote the same or equivalent
parts wherever they occur in the drawings.
Regarding the machine illustrated in Figures 1 to 3, this is adapted to reduce
the cylinders in diameter, forcing the metal consequent upon reduction into
length in such cylinders.
Referring to the drawings, a represents the cylinder being operated upon.
This cylinder is supported upon a roller bed at each side of the reducing mech-
anisin, consisting of two parallel sets of rollers a, the shaft a¹ supporting these
rollers being supported at either end by bearings b, such bearings heing mounted
on the slides b₁ supported in the guides 2. The slides b' are worked up and
down in the guides 62 by screw gear, similar to that for working the reducing
rollers hereinafter described. in and out. In the case shewn the gearing consists
of a hand actuating wheel 3 on each side, having a bevel tooth wheel in the
lower end of the shaft carrying the wheel 63; a shaft 65 having a bevel toothed
wheel at each end, meshing with the wheels 64; spur wheels 67 on the shaft 65;
pinions 68 meshing with 67, and mitre wheels 610, on the shafts 69; counter
shafts, having a mitre wheel 612 on each end, one of which meshes with 10,
and each of which meshes with a mitre wheel 13 on the end of the threaded
shafts 64, which work in a threaded hole in each of the slides b¹.
The mechanism which operates upon the cylinder x, comprises an annular or
ring frame c, having a plurality of guides c¹ therein, the axes of which are
In these guides c¹, rect-
arranged radially through the centre in the frame.
angular slides d fit and work; and these slides carry at their inner ends rollers e,
arranged in skew disposition. The slides d are worked up and down in the
guides e, by screwed shafts f, meshing with threads in said slides, and tooth
wheels g on said shafts. All the wheels g and slides d are worked in and out as
required, simultaneously, by a tooth rack h, mounted on the frame c, and operated

page_text: by either of the two hand wheels i, each of which is mounted on one of the spindles
or shafts f, on either side of the machine. When these hand wheels i are worked
one way, the rollers e are moved in, and vice versu.
Two or more of the rollers e are mechanically revolved, and act as motor rollers
for revolving the cylinder ; and the hot cylinder is revolved at a high rate of
speed. are the driving shafts of these rollers; and they are adjusted laterally
by moving their bearings nearer to and further from the centre of the cylinder,
simultaneously with the movement of the slides d. This is effected by mounting
the bearings on the end of the slides, similar to d, mounted in guides ¹, the
said slides being moved in and out by spindles, which are worked from the
hand wheels, by a sprocket wheel fixed on the spindle f carrying this wheel;
a sprocket chain 7, and sprocket wheels on the shafts 2; and the sprocket
chain connecting said wheels 12. This gearing for the driven wheels is pro-
vided on one side of the frame c only; the mechanism on the other side of the
frame, being merely the roller bed for supporting the cylinder x.
Prior to the cylinder being operated on in this machine, it is rolled by any
suitable rolling machine to the exact thickness required, but to a larger external
diameter; which of course can be done by allowing greater sectional area in the
block of metal, from which the cylinder is to be made, than is actually required
in the finished tube. Then the diameter is reduced to that actually required,
by setting the rollers e inwards at a radius less than the radius of the tube or
cylinder to be operated upon, namely, to the radius of that of the finished cvlin-
der required; which transfers the excess of diameter into length, without in-
creasing or varying the thickness.
In action, when the tube is started under the rollers e, these rollers being on
the skew, and revolving at a high speed, revolve the cylinder x, and reduce its
diameter, and move it longitudinally as well; and as it is revolved it traverses
over one or other of the roller beds, the rollers a revolving with it. The reduc-
tion of diameter may be effected by one passing or a plurality of passings
under the rollers e.
Referring now to the modified machinery shewn in Figures 4 and 5, by this
machine, in lieu of the cylinder being moved longitudinally to and fro, as with
the former machine, it is simply rotated by the radially disposed outside parallel
rollers m; while, internally, it is operated upon by the skew rollers n, which are
moved to and fro axially within the cylinder .. In this case, instead of having
a single annular frame c, there are two frames c, one on each end of the rollers m;
and these rollers are borne by bearings m² at each end, which are moved or
adjusted in and out radially, exactly as in the machine shewn in Figures 1 and 3.
One of the rollers m on each side of the machine is a driven roller, and these
are operated by shafts m', which are operated from a suitable motor. The skew
rollers n are mounted in a circular carrier frame n¹, which is fixed to, supported,
and operated, by a hollow shaft at either end; this shaft being mounted in
bearings o¹. The shaft o is moved to and fro axially through the bearings o¹ by
any suitable power. In the case shewn, the hydraulic ram s is connected, by
connecting rods s¹, to the ring 2, fitted in a groove in the end of the shaft o;
and this ram moves the shaft o longitudinally, too and fro.
The rollers n are supported in bearings p, the shanks p' of which pass through
guides, and through slots in an internal conical cage q, they being reduced
where they pass through the slots, and provided with heads on the inside of
the cage. The cage is guided at either end by internal bearings o³ on the
shaft o.
If the cage be moved longitudinally, the bearings of the rollers n
will, by their action and construction just described, be moved in and out towards
the cylinder. This longitudinal movement of the cage q is effected by an inter-
nal rod r, the inner end of which is threaded, and meshes with one end of the
cage g; while the other end projects through the end of the shaft o, and is pro-
vided on its outside with a hand operating wheel r¹, by which it is revolved.
The axes of the rollers m and n are arranged to operate in the same radial line.

page_text: Normally, the inside skew rollers, and the external rollers, will be in the same
radial lines, and are held in this position; but when it is desired for certain
operations to set the inside rollers outwards, when the cylinder is in place, the
shaft is adapted to be rotated a partial revolution, to bring the inner rollers
between the outer rollers; but normally the only motion the slide shaft and the
internal roller carriers have, is a longitudinal one; and the rollers are not directly
driven.
In one mode of operating, the cylinder or shell to be operated upon is, in the
prior rolling out action—that is, the rolling action proper-made larger in dia-
meter than that required. Then the cylinder is placed in position in the roller
cage or cradle, and the outside rollers act upon it, and reduce it in diameter to
that required, and the inside rollers being set to produce the internal diameter
and thickness required, they are moved to and fro longitudinally by their carrier
shaft. Or, as a modification, if the external diameter of the shell be that exactly
required, and the plate have an excess of thickness, then this excess of thickness
is rolled off, and converted into length, by operating upon it by the internal
skew rollers, which are passed longitudinally through it. Or, any
variations of the methods of obtaining the required diameter and
thickness, by first making the cylinder of a diameter or thickness
which is not the finished diameter or thickness, and then rolling
it to the required diameter and thickness, by the machinery herein
described, may be employed.
With regard to the machines herein described, these are not restricted under
this invention to the use solely for operating upon the particular cylindrical
articles specified, nor in the manners particularly specified; and they may be
wholly or partly employed in connection with the manufacture of similar hollow
bodies or articles, otherwise made than as described, whether of plain, corru-
gated, or similar form.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. The manufacture of seamless metal cylinders or tubular bodies of the dia-
meter and also thickness required, in the manners or by the processes or methods
and means, substantially as herein described.
2. The herein described process of manufacturing seamless metal cylinders or
tubular bodies, and of the diameter and also thickness required, consisting of
first producing a perforate seamless blank or billet from which the cylinder is
to be made, then rolling said blank or billet circumferentially until it is of the
approximate size, but in excess in diameter or thickness of that of the cylinder
required, and then reducing this excess of size by rolling it at points all round
simultaneously, from one end to the other.
3. The herein described process of manufacturing seamless metal cylinders or
tubular bodies, and of the diameter and also thickness required, consisting of
first producing a perforate seamless blank or billet from which the cylinder is to
be made, then rolling said billet or blank until it is of larger diameter than
required in the finished cylinder, but of the required thickness, and then sub-
sequently reducing the diameter by rolling it at points all round in substantially
the same transverse plane of said cylinder, from one end to the other, whereby
the excess of metal caused by the reduction is transferred into a longitudinal
extension.
4. The herein described process of manufacturing seamless metal cylinders or
tubular bodies and of the diameter and also thickness required, consisting of
first producing a perforate seamless blank or billet from which the cylinder is
to be made, then rolling said billet or blank until it is of the external diameter
required in the finished cylinder, but having an excess of thickness, and then sub-
sequently reducing the thickness by rolling it internally at points all round, from

page_text: one end to the other, whereby the excess of thickness is rolled off, and transferred
into a longitudinal extension.
5. In the manufacture of seamless metal cylinders or tubular bodies, the
herein described method of producing shells or bodies of the diameter and thick-
ness required, by revolving the cylinder of the approximate size required as
regards diameter or thickness, and acting upon it by rollers as it is revolved, and
moving the said cylinder or. body longitudinally in relation to the said rollers,
or the rollers longitudinally in relation to the cylinder or body; substantially as
herein set forth.
6. Machinery for rolling metal cylinders or tubular bodies to the thickness
and also diameter required, comprising a plurality of rollers disposed all round
the cylinder, and adapted to act and press in radial lines in relation to the cen-
tre of said cylinder, said rollers being adjustable in said radial direction; sub-
stantially as set forth.
7. Machinery for rolling metal cylinders or tubular bodies, having the main
parts arranged and adapted to operate substantially as set forth with reference
to and shewn in Figures 1 to 3; and Figures 4 and 5, respectively, of the drawings.
8. The machinery. for rolling metal cylinders or tubular bodies to the thick-
ness and also diameter required, having its parts arranged, constructed, and
adapted to operate particularly as set forth with reference to and shewn in the
drawings.
Dated this 22nd day of August 1900
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.