IMPROVEMENTS IN MACHINERY FOR MAKING CORRUGATED FURNACES AND FLUES FOR STEAM BOILERS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, JAMES GRAY LAWRIE, of 2 Westbourne Terrace, Glasgow, in the County of
Lanark, North Britain, Shipbuilder, do hereby declare the naturo. of my said
invention for "IMPROVEMENTS IN MACHINERY FOR MAKING CORRUGATED FURNACES
AND FLUES FOR STEAM BOILERS," and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement that is to say :—
My said Invention has for its object the making of corrugated furnaces and
Alues for steam boilers in an improved manner, and by machinery which first
corrugates the metal plates or sheets without bending them into the cylindrical
form of the furnace shell or flue, such bending being effected by a subsequent
operation. The corrugation of each plate is effected in an hydraulic press by
placing the plate on a fixed bed formed with a suitably corrugated surface and
by forcing down upon it an upper block or plate having its under side formed
with corrugations which are counterparts of those of the fixed bed beneath.
A suitable marginal portion of the plate is in some cases by preference left
uncorrugated at the four edges of the plate, to facilitate the welding or riveting
of the plates to each other or to other parts of the structure. The corrugated
plates are bended into the final shape of the furnace shell or flue upon a mandril
shaped externally to fit more or less of the interior of the furnace shell or flue the
plate being bended down upon the mandril by means of a concave block formed
with a suitably corrugated surface and forced down by hydraulic apparatus. Only
a segment or portion of the shell is thus bended at a time, the corrugated plate
being moved to the extent of the segment after each bending operation until
completely bended into the cylindrical form.
And in order that my said Invention and the manner of performing the same
may be properly understood there are hereunto appended two sheets of explanatory
drawings to be hereinafter referred to and representing my improved machinery.
Figure, 1, on sheet, 1, of the drawings is a plan, figure, 2, a vertical section and
figure, 6, is a side elevation of an hydraulic press as constructed according to my
Invention for corrugating the plates or sheets prior to bending them into the form
of furnace shells or flues. Figure, 3, is a section of a portion of a corrugated plate
D

page_text: showing the form of corrugation which I prefer to use (and which is that of an
harmonic curve); it must however be understood that I do not restrict myself to
that particular form of corrugation. Figure, 4, is a section of a modification of the
upper pressing block of the press. Figure, 5, is a face view of the corrugated
plate as made with an uncorrugated margin. In figure, 5, the lines within the
margin do not represent angular edges but merely indicate the corrugations.
Figures, 7, and 8, on sheet, 2, of the drawings are a plan and a side elevation of
one modification of my machine for bending a corrugated plate into the form of a
furnace shell or flue, and figure, 9, is a corresponding transverse vertical section.
Figures, 10, and 11, are a side elevation and transverse vertical section of one 1
modification of mandril to be used in the bending machine; whilst figure, 12,
shows the positions of the parts when the bending of a corrugated plate is being
commenced. Figures, 13, and 14, are transverse vertical sections of other
modifications of the mandril, and figure, 15, is an end elevation of part of a
bending machine slightly modified from that shown in figures, 7, 8, and 9. In
these drawings the same reference numerals are used to mark the same or like
parts wherever they are repeated.
:
The machine for corrugating the plates or sheets and which is shown on sheet, 1,
of the drawings, comprises a castiron base or bedframe, 21, having connected to
it by four strong pillars or rods, 22, of wrought-iron or steel, an upper castiron
frame or entablature, 23; and to the under side of this entablature there are fixed
four inverted bydraulic cylinders, 24, and also four smaller inverted hydraulic
cylinders, 25. The rams, 26, of the larger cylinders, 24, and the piston rods, 27,
of the smaller cylinders, 25, are represented as working through stuffing boxes;
but these parts as well as the valve details and the pipes for leading the water
to and from the cylinders (and which parts are not fully shown) may be arranged
as in any suitable existing bydraulic apparatus. An upper movable massive
box-like castiron pressing frame, 28, is connected by lugs and joint pins to the
piston rods, 27, of the smaller cylinders, 25, so as to be suspended theroby, and
this pressing frame is raised by means of these smaller cylinders between the
pressing operations. Upon the bedframe, 21, thero is fixed a plate, 29, having its
upper surface corrugated, and the under surface of the upper pressing frame, 28,
is correspondingly corrugated; or the upper frame, 28, may be made with a flat
under surface and may have a plate with a corrugated under surface fixed to it,
such plate as well as the lower plate, 29, being changeable, when the plates to be
corrugated or the corrugations required are of different sizes or forms. Or provision
for plates of different sizes may be made in the manner indicated in figure, 4,
which shows a modification of the upper pressing frame, 28, with portions of the
corrugated surface formed upon changeable pieces, 30. In figure, 2, a flat plate, 31,
is represented as having been inserted between the lower and upper corrugated
surfaces, ready for being corrugated, the corrugating operation being effected by
setting the valves to admit the water (or other suitable liquid) under pressure into
the upper ends of the larger cylinders, 24, so that their rams, 26, may be forced
down to press down the upper pressing frame, 28. The plate, 31, then becomes
compressed between the lower and upper corrugated surfaces, and is thereby made
to assume the desired corrugated form. If considered desirable the plate, 31, may
be heated when about to be subjected to the corrugating action. When the
plate, 31, has been compressed as described the upper pressing frame, 28, is raised
and the plate removed, the raising of the frame being brought about by the
pressure of the water in the lower ends of the smaller cylinders, 25, the valves
being then set to allow the water to exhaust from the upper ends of the larger
cylinders, 24. Valves may be arranged for admitting water into and out of the
smaller cylinders, 25, or the full pressure may be constantly maintained in them,
the operations being entirely effected by admitting and exhausting the water into
and from the larger cylinders, 24. Or the smaller cylinders, 25, may be dispensed!
with, and the larger cylinders be provided with pistons having annular surfaces on
their under sides, on which annular surfaces the water may act for raising the

page_text: rams, 26, and the pressing frame, 28, the latter being in that caso suitably connected
to the rams.
:
In the bending machine shown in figures, 7, 8, and 9, sheet, 2, two end
standards, 33, which are bolted down to a sole plate, 34, and connected at their
lower parts by side frames, 35, have fixed on their upper ends an upper frame or
entablature, 36. On this entablature, 36, there are fixed by means of broad
Danges cast on them two larger inverted hydraulic cylinders, 37; and two smaller
ones, 38. The rams, 39, of the larger cylinders, 37, have connected to them by.
lugs and joint pins, a block, 40, through which the pressure is transmitted to a
bending block, 41, of peculiar form; and this bending block, 41, is made with
journals, 42, which pass through guide blocks, 43, fitted to slide vertically in
openings in the standards, 33. On the ends of the journals, 42, rings, 44, aro.
loosely fitted, and are connected by swivel joints to the rods, 45, of the smaller
cylinders, 38, the block, 41, being lifted when required by means of these
cylinders acting through the rods and rings. Below the block, 41, there is a
roller or mandril, 46, which rests by means of journals, 47, in semicircular bearings
formed for it in the standards, 33; whilst on the outer parts of the journals
there are loose rings, 49, which can be connected as shown, by means of lugs
and joint pins to the rings, 44, on the journals, 42, of the upper block, 41. This
arrangement is provided for the purpose of raising the roller or maudril,. 46,
along with the upper block, 41, by means of the smaller cylinders, 38, 'when'
required.
The upper bending block, 41, is made with four concave surfaces which, aro
corrugated to fit the corrugations of the plate, and which, on the plate, 31, being.
entered between the block, 41, and the mandril, 46, as shown in figure, 12, bend..
the plate down upon the latter. Only a part of the plate, 31, is. bended in this
way at once, and after one part has been bended the upper block, 41, is raised and
the mandril, 46, and the plate, 31, moved further round with it to have the next,
portion bended. That one of the concave surfaces of the block, 41, which first.
acts on a plate, 31, and the corresponding part of the mandril, 46, are shaped so as
to fit the uncorrugated margin of the plate, that is with uncorrugated parts.
corresponding to the margin, whereas the concave surface or surfaces of the
block, 41, and corresponding parts of the mandril for operating on the middle
portions of the plato are entirely corrugated, and are turned round in succession.
into the positions for operating on the plate. In a similar manner the parts of
the block, 41, and mandril, 46, which act on the last part of the plate, 31, are mado
with uncorrugated portions corresponding to the margin at that side of the plate."
The block, 40, which is attached to the rams, 39, of the large cylinders, 37, is
formed on its underside to fit the middle portion of any one of the concave surfaces
of the block, 41, when turned up in consequence of the opposite one being turned
into position for a bending operation, the block, 40, being raised a sufficient height
to allow of the block, 41, turning under it when its position is boing changed.
In bending the corrugated plate, 31, round the mandril, 46, it is made to enclose
the mandril which is prevented by the corrugations from being drawn out in its.
entire state. To enable the mandril, 46, to be withdrawn it is made in segments
which can be made to collapse, the construction being shown in figures, 10, and 11.
What may be termed the outer shell of the mandril consists of three principal.
segments, 50, and a fourth narrower one, 51, which läst is formed with parallel
edges. Rings, 52, are placed over the journal parts, 47, and the segments are
tightened and held out against the insides of these rings by keys, 53, driven in.
between the narrow segment, 51, and one of the larger segments, 50. The interior
of the combined segments is made with a slight taper, and an inner mandril, 54,
(which may be either solid or hollow) .having a corresponding reversed taper is
driven in and makes the complete mandril practically solid. For the purpose of
withdrawing the mandril from a bended furnace shell, the inner mandril, 54, is-
first driven out, and then the keys, 53, which are made slightly thicker towards
their inner edges are driven inwards. This sets free the narrow segment, 51,

page_text: which in its turn is forced inwards, after which the other segments, 50, can be
turned inwards and removed end ways without difficulty.
Instead of making the mandril (46) as hereinbefore described with its surface
a complete counterpart of the interior of the bended furnace shell, it may be made
with a corrugated acting surface corresponding to only a part of the entire furnace
shell, the shell whilst being bended being made to slide over such acting part of
the mandril without the mandril being turned with it. For working in this way,
the mandril may either be a solid one, 55, as shown in figures, 13, and 15, or it
may consist, as shown in figure, 14, of a lower part, 56, having an upper acting
part, 57, fixed to it by bolts, such upper part being changeable to suit furnace shells
or flues of different sizes. In figure, 15, a modification of the frame standards, 33,
is shown being designed to facilitate the removal of the mandril, 55, and the
furnace shell after the shell has been bended upon the mandril. Instead of a
bearing for the journals of the mandril being formed in the standard, 33, itself
a sufficiently large opening is made in the lower part of the standard to receive
a pillow or bearing block, 58. This bearing block, 58, is made with a slightly
projecting flange on its outer side only, to admit of its being withdrawn in a
direction parallel to the mandril, the block being secured in position by means of
bolts passed through lugs, 59, on its inner face and on the inner side of the standard
as indicated by dotted lines. The mandril is temporarily supported whilst the
bearing block is removed in this way, and thereafter the mandril with the furnace
shell on it, can be withdrawn upon a truck or in any other convenient way.
The proper positions of the pressing block, 41, and mandril, 46, may be
determined by means of key ways or notches, 60, 61, formed in their journals,
a corresponding key way or notch, 62, 63, (or more than one) being formed in each
guide block or bearing, 43, 58, and a key being inserted in the coincident journal
and bearing notches to prevent any shifting of the parts during the bending
operation. These keys are of course withdrawn when the pressing block, 41, and
mandril, 46, have to be turned to change their positions.
My improved bending machine hereinbefore described may be used for bending 3
plates which have been corrugated by machines differing more or less from that
shown on sheet, 1, of the drawings and hereinbefore described.
I do not restrict myself to the precise details herein described and delineated
provided that the distinctive features of my Invention are retained,-theso being,
1, the making of corrugated furnaces and flues for steam boilers by means of 3
hydraulic machinery constructed and worked so as to first corrugate the plates and
subsequently bend them into the forms of the furnaces and flues; 2, the corrugating
of the plate by subjecting it to hydraulic pressure between corrugated plates or
blocks of a general flat form; 3, the bending of the plate into the form of the
furnace shell or flue by means of a concave block forced by hydraulic pressure 4
so as to press the plate upon a mandril having a corrugated surface which is a
counterpart of the intended interior of the furnace or flue; 4, the construction of
collapsible inandril bereinbefore described more particularly with reference to
figures, 11 and 12 of the drawings; and 5, the construction of segmental mandril
herein before described with reference to figures, 13, and 14, of the drawings,
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 application and use in the making of corrugated furnaces and flues for
steam boilers, of hydraulic machinery constructed and worked so as to first 50
corrugate the plates and subsequently bend them into the forms of the furnaces
or flues such machinery being arranged and operating substantially as bercinbefore
described.
2.-The corrugating of the plate by subjecting it to hydraulic pressure between
corrugated plates or blocks of a general flat form substantially as hereinbefore 55
docasi

page_text: 3.-The bending of the plate into the form of the furnace shell or flue by means
of a concave block forced by hydraulic pressure so as to press the plate upon a
mandril having a corrugated surface which is a counterpart of the intended interior
of the furnace, substantially as hereinbefore described.
4. The construction of collapsible mandril hereinbefore described more
particularly with reference to figures, 11, and 12, of the accompanying drawings.
5. The construction of segmental mandril hereinbefore described with reference
to figures, 13, and 14, of the accompanying drawings.
Dated this twenty-seventh day of September 1884.
EDMUND HUNT,
Applicant's Agent.