Improved Means and Apparatus for the Manufacture of Corrugated Flues for Boilers.
Year: 1889

page_text: Date of Application, 19th June, 1889
Complete Specification Left, 19th Mar., 1890-Accepted, 7th June, 1890
PROVISIONAL SPECIFICATION.
Improved Means and Apparatus for the Manufacture of Corrugated
Flues for Boilers.
I, DOUGLAS DIXON of 65 Hereford Road, Bayswater, Middlesex, Engineer, do
hereby declare the nature of this invention to be as follows:-.
The object of this invention is the manufacture of corrugated boiler flues by
improved methods.
In carrying out this invention, the first process consists in forming the corrugations
on the plates. Heretofore this has been effected by transversely or longitudinally
corrugated rollers, or by corrugated rollers working on corrugated blocks, by which
means, the corrugations have been almost entirely, or to a large extent, taken out of
the thickness of the plates themselves, thus involving stretching and straining of the
metal. By means of the present improved method or process the plate is bent into
such corrugations as may be desired without reduction in thickness as well as
without stretching or straining the metal. This is effected by means of shaping dies
arranged in longitudinal sections with faces so shaped that when the sections are
brought together they form dies of the shape of the required corrugations. One set
of these dies when together side by side, forms the concave die corresponding to the
convex side of the corrugation to be made in the plate, and another die operating as
a hammer or plunger has its face convex shaped to form the concave side of the
corrugation to be made in the plate. The convex die may be placed either as the
upper, or as the lower die, but it is preferred to place it above. The upper die or
plunger has a vertical movement, equal to the depth of the corrugation, and a lateral
movement equal to one half of the difference between the chord and the curve of the
corrugation. One section of the lower die has a lateral movement during the act of
shaping equal to the difference of the chord and the curve of the corrugation, and the
movements must be so arranged, that when the part of the plate to be operated upon
is in the act of being gripped by the dies, the centre of the convex die shall be
exactly in line with the centre of the space between the two sections of the concave
die, and this relative position must be maintained as the space decreases.
The requisite vertical and lateral movements may be communicated by any suitable
mechanism. It is evident that as the two sections of the concave die are brought
together, and as the convex die approaches them in its relative position, the plate is
bent to the shape of the dies without stretching or straining the fibres of the metal.
In practice I prefer to use this method of forming the corrugations in connection
with another set of convex and concave dies which will act as a finisher. The concave
die of the finishing pair of dies and one section of the concave corrugating dies may
be formed in one piece. The finishing dies have imparted to them a vertical move-
ment equal to the depth of the corrugation, to allow of each corrugation of the plate
as formed by the corrugating dies, being moved forward in line with the said
finishing dies, and there subjected to pressure and firmly held while the next section
of the plate is being operated on by the corrugating dies.
The other section of the concave corrugating die may be made of a breadth greater
than half the width of one corrugation, such additional breadth being made with a
flat face or surface. Directly over this flat face or surface a bar is coupled to this
section of the concave die by means of clamps, or other suitable arrangements which
allow of the bar being raised sufficiently to admit the flat part of the plate passing
freely under it, and of the bar being lowered so that it shall take a firm grip of the
plate. When this bar is raised, the said section of die which carries it can be moved
backwards a distance equal to the width of plate required for the formation of one
corrugation and when moved forward with the bar lowered it brings the last made

page_text: corrugation between the finishing dies, as well as the next section of plate into
position to be acted on by the corrugating dies, after the closing of the anishing
dies.
It is obvious that if desirable to give the ends of the plate a curve, in order to
facilitate their entry between the bending rolls, this can be readily effected by curving
the ends of the corrugating and finishing dies. It is also obvious that if it is
required to leave a plain or uncorrugated piece at the sides, or any other portion of
the plate, it is only necessary to keep the convex corrugating and finishing dies apart
from the respective concave dies during the passage of such portions of the plate.
It is desirable that this apparatus should be placed parallel and close to the heating
furnace, so that the plate may be only drawn out of it as the corrugation proceeds.
According to the second part of my invention, the bending of the corrugated
plates is effected by means of three transversely corrugated rolls, two of which may
be on the same horizontal plane and rotating in stationary boxes, or the boxes of one
or both of these rolls may be made capable of horizontal and vertical movement for
adjustment of the roll, if necessary, to suit various diameters of flues. The third or
bending roll is carried by trunnions so arranged that it can be lowered into the
bight between the two. other rolls when the plate is to be bent. The axis of the
trunnions or discs is a sufficient distance above and behind that of the lower roll,
over which it is placed to raise the bending roll, when brought over it, enough to free
the corrugations and allow the bent flue to be removed end wise. The bearings of
these trunnions are fixed to the housings outside and around the boxes of the lower
roll. I prefer to make these trunnions in the form of discs, or parts of discs, with
jaws projecting over the housings, and if necessary partially supported by them to
receive and carry the boxes of the bending roll. One part of the circumference of
these discs may be cogged for a sufficient distance to permit of their being partially
rotated or revolved as required by means of coupled worm wheels, or other suitable
mechanism.
The lower rolls are driven by a pinion or pinions on the driving shaft below and
between them, and the bending roll is furnished with an overhanging pinion geared
into that of the roll, round which its trunnions are placed. In order to clear the
pinion of the bending roll, when down in the bight, the pinion on the other lower
roll is placed far enough away from the housing to leave room for it. The box of the
bearing of the driving end of the bending roll is fixed in its trunnion jaw in a
suitable manner. The box on the other end is made with a suitable arrangement to
connect with, and disconnect easily from the jaw of its trunnion, so that when it is
relieved from the weight of its end of the roll by counter balancing, or otherwise,
the trunnion can be rotated or revolved by means of the worm wheel, and the jaw
withdrawn from under the box a sufficient distance to permit of the flue being passed
out end wise, and leaving the box hanging on the end of the roll. After the flue is
removed the trunnion can be turned back into its former position, and the box con-
nected with it, when it is ready again to take the weight of that end of the roll. For
this purpose the driving shaft of the worm wheels is uncoupled from the worm wheel
of the other trunnion.
To assist in raising the bent flue into position for removal endwise, a roller is
employed with its ends resting on supports, on which it can slide and attached at
each end by a connecting rod to the jaws, or to part of the disc in such position that
when the bending roll is raised and presses against the inner side of the flue, it shall
press against the outer side of the flue and follow it up while being raised to the
vertical position over the lower roll. To receive the weight of the flue after it has
passed the vertical centre, a small roller is placed in a suitable position in front and
this roller is so arranged that it can be raised or lowered as necessary to suit the
diameter of the flue and adjust it to position for withdrawal. To aid in this, a small
strip of metal may be rested against the roll, to support the other side of the flue, in
such position that when the roller is lowered, the flue is freed from the corrugations
in the lower roll. The flue is then in a position to be removed end wise by any
suitable means.
This roller can be made double the length of the flue and may have

page_text: a bearing at its middle and the strip laid against the roll may be a prolongation of a
rail of the same length as the roller, forming a continuous cradle, along which the
flue can be slid. The flue can then be transported by any suitable means to where
the weld is to be made, but I prefer to place it on a carriago specially constructed for
the purpose.
This carriage (which may also be used instead of the roller and rail
above described for withdrawing the flue from the bending rolls) consists of a frame
mounted on four wheels which may be flange to run on rails.
Placed longitudinally over each set of wheels are two partially corrugated rollers,
on and between which the flue rests. The hearings of these rollers are carried in
moveable boxes, acted upon by set-screws worked by worm wheels, or otherwise, in
such manner that they can be made to approach each other, or drawn apart to suit
the diameter of the flue, and the heighth to which it is to be adjusted. The ends of
these rollers at the rear of the carriage are fitted with hand wheels, so that by moving
one or both of them the rollers can be rotated and the flue turned round into any
required position. The cross pieces at the ends of the carriage are bell shape in the
middle to allow of the flue being run over the anvil. To assist in lowering the flue
into position between the rollers and removing it, two racks are fitted in a sloping
direction from the top of the bell shaped part to the end of the cross pieces at one
side of the centre, and a light bar with a pinion on each end to work in the racks is
strapped, so that it may travel along the rack. The bar is fitted with a crank at one
end, by turning which, it is moved up or down against the flue. When the flue is
placed and adjusted on this carriage with the lap for the weld along the centre of the
bottom, the bottom part is run over a forge fire, or into a furnace to be brought to a
welding heat.
I prefer to use an improved furnace hereafter described and constituting the third
part of my invention, heated by gas on the reversing regenerative principle, the
flame passing lengthwise through the furnace, which is furnished with a concave
crown or lid consisting of an iron casing lined with fire bricks and capable of being
raised and lowered a sufficient distance to allow the portion of the corrugated flue to
be welded, to pass endwise heneath it. To prevent the escape of heat, the sides of
the casing may be corrugated to correspond with the internal surface of the flue, so
that it can be lowered close down when the flue is in the furnace. When the anvil
is fixed close to the furnace, the crown or lid may be carried by a prolongation of the
anvil arm. Adjustable side pieces with similar corrugations may also be closed against
the flue underneath and outside, when placed in position for heating. A portion of
the flame will then pass between the furnace crown or lid and the internal surface
of the flue. When the flue is ready for withdrawal, the lid or crown may be lifted and
the side pieces moved out to free the corrugations. The carriage bearing the heated
flue can then be run along to an anvil, while at the same time the lapped part of the
flue can, by means of the mechanism on the carriage, be turned into the position
desired for welding by a suitable hammer.
The anvil can be placed in line with the centre of the furnace and close to one end
of it and on a level with the bottom of the flue, the rails on which the carriage travels
being continued on each side of it. By this arrangement it is possible to weld the
flue bit by bit as it comes out of the furnace by a hammer or swaging arm, or to roll
weld it by drawing it continuously between suitably corrugated rolls. In the case
of welding by means of hammering or swaging, the lower concave and corrugated
die of the anvil must be capable of being lowered by suitable mechanism to allow
the corrugations of the flue to pass freely, and of being raised again into position.
The hammer furnished with a convex and corrugated face corresponding with those
on the flue, and on the lower die may be worked by means of a steam piston, or it
may be fixed to a rocking arın suitably driven, fixed on the upper arm of the anvil.
I prefer to weld the flue continuously by passing the lap direct from the furnace
between suitably corrugated rolls, rotating transversely, to the line of the lap. Means
are provided for bringing the rolls closer together to complete the weld. The lowe
roll which is slightly concave and rotated in boxes fixed to the lower arm of the anvil
may be driven slowly by any suitable means, and the upper roll which is slightly

page_text: convex and rotated in boxes fixed to the upper arm of the anvil projecting into the
flue may be turned by the corrugations on the internal surface of the flue or both
rolls may be driven by coupled worm wheels acting upon pinions on the shafts of the
rolls. The arms of the anvil must be sufficiently long to allow the whole length of
the flue to pass between the rolls.
D
101
T 1000
H GARDNER,
166, Fleet Street, London, Agent for the said Douglas Dixon.
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:
This invention relates to certain means and appliances for crimping, and then
forming corrugations in metal plates, by pressure. In bending such corrugated
plates into cylindrical shape. In heating the overlap and in welding by rolling, or
by pressure or hammer and dies.
DESCRIPTION OF DRAWINGS.
Sheet 1 shows the arrangement of the crimping dies of which Figure 1 is an end
elevation, Figure 2 a side elevation. Figure 3 is a plan. Figure 4 is a vertical
section through the dies.
Sheet 2 shows the improved bending rolls of which Figure 5 is a vertical
longitudinal section, Figure 6, Sheet 3, being an end elevation.
Sheet 4, Figure 7, is an end elevation of the traversing carriage.
Sheet 5, Figure 8, is a cross section of the regenerativo furnace, showing the flue
on the carriage in position for heating. Figure 9 is a longitudinal section of the
furnace showing the welding rolls in position near end of same.
Figure 10 is a plan of the welding and Figure 11 is a section on line x x of
Figure 9.
Figures 12 and 13 are a side and end elevation respectively of an alternate
arrangement for welding by means of a bammer and anvil."
On Sheet 1, A is the frame supporting the dies and carrying the shaft B by which
they are operated, and which is driven by a worm C and pinion C¹. D and D¹ are
the upper and lower crimping dies, the lower of which also acts in conjunction with H.
as the feed, and D2 and 3 are the respective finishing dies. The die D is made with
a tongue d¹ at each end which works in corresponding slots in the frame and is
carried and operated by connecting rods E, E, working on eccentrics b, b, on shaft B.
The connecting rods are furnished with small rollers e, e, to relieve the friction on the
eccentrics. The ends of the die D' rest and slide on a portion of the frame in which
there are grooves a a. Sliding bars F, F are fitted in these grooves having pro-
jections ff, on their forward ends engaging in slots d² in the die D' and the backward
ends are firmly fixed to straps f, to which the connecting rods G, G, working
on the eccentrics 61, 61, on the shaft B are coupled. The sliding bars F, F, with
their projections f, f, and straps f¹, f¹, impart the necessary motion to the die D',
and are so adjusted that their stroke is longer than that to be imparted to the die,
which by this means will remain at rest for a short interval at each end of the
stroke.
Mounted on the die D' is the tilting cylinder H having closed ends, with the
opposite lower front and upper back quarters of the circumference cut out longi-
tudinally for the whole length up to the closed ends. Bearings projected from the
closed ends are carried in boxes on the die D¹, and projecting backward from each

page_text: end is a lever h with an adjustable end-piece h¹ acted upon by set-screws h³, h³, and
bearing on the upper bevelled surface of the strap f¹.
The finishing dies D2 and D³ are hung to rocking bars I, I, (which are carried on
pins working in bearings a³, a³, on the frame A) by means of the connecting
rods K, K, L, L, by which they counter balance each other. The die D2 has
tongues at the ends which slide in corresponding grooves in the frame A. The
connecting rods K, K, are fastened to the tongues 3 on each end of the die D
which project through corresponding slots in the frame A, and the connecting rods L, L,
have collars 1, 1, on their lower ends which fit into recesses and are held in position
by covers d', d. The recesses are made as much deeper than the collars 1, 1, as the
stroke to be given to the die. The blocks 1, 1, fastened to the side of the die D' by
the studs, and having projecting arms 13, 13, are coupled to the rod 1, by the
movement of which they can be pushed into the recess underneath the collar, or pulled
out over the cross bar of the frame A, as shown by dotted lines in Figure 3. The
lower die D³ has transverse projections d³, ds, cast on it, or otherwise fastened to it
and stepped so as to correspond with the large and small eccentrics 3, 63 and 4,
respectively, on the shaft B and the corresponding eccentrics m and m² on the shaft M,
which is worked by means of the toothed wheels m², m², gearing into corresponding
toothed wheels 8, 78, on the shaft B. These eccentrics are so adjusted that at the
point in the revolution of the shaft B where the die D³ begins to be lowered, it shall
rest on the small eccentrics 4, 6* and m', m², till it reaches its lowest point, where it
shall remain for a suitable interval before being raised, and kept in position during
the remainder of the complete revolution by the large eccentrics ³, b³, and m, m.
1
To support the plate P while it is being fed to the machine a roller N is suitably
placed. is a light shaft carrying three or four discs having their peripheries
corrugated to suit the corrugations of the plate. One or more of these rollers can
be adjusted to suit the width of the plate. When the end of the plate P is advanced
from the heating furnace, so as to bring it far enough under the open sided
cylinder H for one corrugation, the shaft B is rotated in the direction shown by the
arrow, the connecting rods G, G, pull the straps f¹, f, and the sliding bars F, F,
forward, the bevelled tops of the straps f₁, f, lift the levers h, h, and bring
the forward segment of the open sided cylinder H down on the plate which it grips
firmly on the back upper part of the die D'. The straps f, f, then push the die D¹
forward carrying the plate with it to feed the plate P up to the position for being
crimped by pressure by D, which acts in conjunction with D¹ for that purpose. The
die D is then raised and simultaneously the lower crimping die is moved back for the
cylinder H to grip a fresh part of the plate which it brings forward for being crimped
as before explained, the eccentrics 64, 64, m', m' having taken the weight of the die D
and lowered it, raising at the same time the die D' enough to allow the portion just
crimped to pass between them, the eccentrics 63, 63, m, m have again raised the die D'
and lowered the die D' and the eccentrics b, b, lower the die D, the remainder of the
downward and forward strokes completes one corrugation. The action of the upper
die D is somewhat eccentric and presses upon the metal plate P without thinning the
metal of said plate. When the die D begins to rise for a succeeding feed, the sliding
bars F, F, and straps f1f1, begin to move backwards and relieve the pressures on
levers h, h, which frees the open sided cylinder H from its grip on the plate, the pro-
jections ff, then grip the front part of the die D₁ and push it backward a distance
equal to the width required for one corrugation. If a plain piece of plate is required
to be passed through, or an uncorrugated margin to be left, it is only necessary to
withdraw the blocks 1, 1, to the position shown by dotted lines in Figure 3, when
the die D is raised, the frame A then receives the weight of the dio D' and the
collars 1, 1, go down in the recesses when the die D³ is raised.
Figures 5 and 6 show apparatus by which a corrugated plate can be made into a
cylinder to constitute a boiler flue. On Sheets 2 and 3, A, A, are the housings B
and B' the lower rolls and C the moveable upper or bending roll which is mounted
in trunnions D and D¹ having their bearings on the upper part of the housings and
on projection a on the side of the housings. E is the driving shaft with its pinions e

page_text: and e operating on pinions and 6, the latter of which turns a pinion c on roll C.
d, d, are cogged segments cast on or fastened to the discs of the trunnions D and D'
and which gear in the worms F and F on the shafts f, and f1 carrying the bevelled
pinions which are coupled by means of the bevelled pinions g¹ on the shaft G which
is operated by hand wheel g. The bevelled pinion operating the worm F¹ is on a
short sleeve or clutch, so that it can be uncoupled when required, by means of forked
lever. The bearing of the bending roll C at the end next the pinion is carried in a
box formed in the casting of the trunnion D. The hearing at the trunnion D¹ is
mounted in a box d¹ with a cap bolted to it, which together rest in a jaw d³ on the
trunnion. The seat on which the box drests is partially concentric with the
trunnion and has a groove d and slots, which latter correspond with similar pro-
jections at the bottom of the box. There is also a slot and corresponding projection
at the back d. The jaw projects a little over the top of the cap d² in a slightly wedge-
shape form. A bracket is cast on the box, or fastened to it and projects outside
and across a collar c¹ on the end of the roll. The screw c furnished with a collar
working loosely behind a hollow nut tapped into the end of the roll, is threaded into
the bracket and has a hand wheel c¹ at its outer end. By turning this hand wheel,
the bracket is drawn endwise, carrying with it the box d against the collar c'.
This brings the outer projections clear of the slots outside of the box seat, and those
at the back into the groove d. It also relieves the key shaped projection at d', leaving
the jaw free to be turned down into the position that the flue may be removed
endwise. The bottom of the box, and the seat on which it rests are slightly
inclined outwards.
I and I are two toothed racks fastened to the top of the housings. K is a rod with
pinions on each end which gear into the racks and are held in position by the
straps, k¹, other straps ³, k³, slide behind them having pivotted eye bolts 2. The
connecting rods attached to the lugs on the jaws of the trunnions pass through
the eye bolts i, the length of these rods can be varied to suit the diameter of the flue
by means of nuts i³. The connecting rod at i¹ is left without a lock nut to allow it to
slip back through the eye bolt when the jaw is turned from under the roll. k³, k³, k³, k³,
are small discs loose on the rod K which grip the flue and allow the rod to turn
in them.
When the corrugated plate is to be bent, the roll C is lowered into the bight
between the two lower rolls B and B according to diameter of flue, the coupled worm
wheels F, F, serving to adjust it to the diameter of flue to be formed. When the flue
is bent into shape, the trunnions are turned backwards till the roll C is brought to the
position indicated by dotted lines where its axis is at its maximum distance from the
lower rolls, the flue being carried along by the roll C bearing against its inner surface,
the weight of the flue still being borne by the lower roll B. The roller K following
the movement of the flue and being kept close to it prevents the possibility of its
becoming distorted, and when it no longer rests on the lower roll, takes also part of
the weight of the flue and assists its movement. When the flue has passed the vertical
centre, the roller on a carriage brought alongside receives part of weight. When the
cylindrical corrugated tube or flue is to be removed from the roll C, a block in strap h
is screwed down on the prolongation co of the bending roll C, fixing said prolongation
in contact with a pillar H until the weight of the roll is counter balanced. The
box is then moved out by the hand wheel e as described, the bevel pinion
operating the worm of trunnion D is uncoupled, so that the trunnion D¹ only is turned
down by the worm F. The flue is then removed on the trolly, which draws the
corrugated cylinder end on, the trunnion D' is brought back into position under box d
which is screwed back on end into position, the box d¹ is readjusted, the counter
balance is removed and the rolls are ready to receive another corrugated plate.
The trolly or carriage which I purpose using is of the construction shown at
Figure 7 (Sheet 4). L. L, is the frame of the carriage having its cross pieces L¹
bell shaped, or arched at each end, mounted on wheels M, M. N, N, are two partially
corrugated rollers mounted in boxes n, n, on the cross pieces of the frame. n', n', are
two of four set screws working in threads in the boxes n. n², n², are worm pinions

page_text: fitted on one side of the frame. o, o, are worms on the shaft o¹ (operated by the hand
wheel 2) which turn the pinions n³, n², as well as the pinions p, p, and the
shafts P, P, P1, P1, and the pinions p¹ p¹, p', p' and the pinions p², p³, gearing into
and turning the pinions n³, n³, on the other two set screws on the other side of the
machine (of which there is one at each end of the carriage. R is a toothed rack
fastened to the cross pieces of the carriage. S is a light rod having a pinion fixed
on each end (s, s) working in the racks and carrying loose discs s¹, s', s¹, s¹. Sliding
straps,, hold the pinions in gear and a crank s on the end of the shaft or rod S
serves to move it along the rack. One of the rollers N is provided with a bevelled
wheel, worked by the pinion n° on the vertical shaft no actuated by the hand wheel.
The rod S is in place to support the side of the flue as soon as it has passed the
vertical centre, when the rollers N, N, should be at the furthest distance apart in
order that one shall be as near as possible to the rolls. The crank is then turned in
the direction of the arrow till the flue rests on the roller N underneath it when it is
in a position to be run out end wise and is afterwards lowered by the same means, till
it rests on the two rollers where it can be adjusted in position for being run into the
heating furnace. The rollers N, N, support the flue and by turning the hand wheel o³,
the rollers N, N, and their boxes n, n, can be moved along the frame L' to accom-
modate a small or a larger diameter corrugated flue as indicated in dotted lines, the
mechanism S and being moved along the rack R to steady the flue in its
position.
Figure 8 (Sheet 5) shows the carriage described with reference to Figure 7 in
position with the overlapping edges of the flue, which have to be welded, in a
furnace A. This can be heated by gas after the cover or roof C is put on.
Figure 9 shows this furnace in longitudinal section and the appliances by which
the cover can be raised or lowered. Figure 10 is a plan of the appliances.
A is the heating chamber of the regenerative gas furnace. B, B, are the gas and
air ports. C is the moveable crown or lid. c, c, are staples connected by chains e¹, c¹,
passing over sheaves c². c², which are mounted in grooves in the carrying arm D with
the coupled rod c³, the rod c³ has a thread on the end and passes through a lug d and
a wheel nut c. By turning this wheel nut, the lid is raised into the position shown
by dotted lines, when the part of the flue to be welded can be run into the furnace on
the carriage. E, E, are adjustable side pieces. When the part of the flue to be
welded is in the furnace the crown or lid is lowered and side pieces closed against the
outside of the flue to prevent escape of heat.
When the overlaps are sufficiently heated, the cover C is raised and the carriage,
still bearing the weight of the flue, is moved onwards to bring the heated overlaps
into contact with the rollers G, H, for welding purposes. These rollers G, H,
are carried by the anvil F made with a gap long enough to allow a full length
of flue to be passed through the welding rolls, which are driven by the shaft I,
as seen more particularly at Figure 11, and the pinion i gearing into the pinions g,
and on the worm shafts gl and h¹ carrying the worms 9 and ² which gear
into the pinions g³ and ³ on the roll shafts. The lower roll shaft has its bearings
carried in boxes 4, 4, which rest on a forked wedge ³ which is worked by the screw
and hand wheel. The shaft I must be capable of being reversed that the rolls may
be rotated in either direction as required K is a pinion on the lower roll shaft and U
is a rack on the under side frame of the carriage, hinged at the back end and attached
at the forward end to the lever u by which it can be dropped into gear with the
pinion K and secured in that position by a pin u². When the part of the flue to be
welded is sufficiently heated, the crown or lid C is lifted and the side pieces E, E,
withdrawn, the carriage is then advanced until the corrugations on the flue correspond
with those on the welding rolls which are set at the proper distance apart, the rack U
is dropped into gear. When the rolls are started, the pinion K draws the carriage
forward and the flue between the rolls. When the flue has been drawn its whole
length between the rolls, the lower roll is raised by means of the forked wedge h and
the wheel screw he a sufficient distance and the rolls reversed. This operation may
be repeated till a perfect weld is obtained, the part meanwhile being kept hot by its

page_text: passing back into the furnace, if the furnace be sufficiently close to the welding
appliances. If deemed advisable, the welding rolls and anvil may be placed at some
distance from the furnace, and switches placed in the track, so that the welded flue
may be removed, without being repassed through the furnace, and a fresh flue
introduced.
Figures 12 and 13 represent a means by which the welding can be effected by
steam, hydraulic, or other agent. A is the cylinder. F the anvil, as before. G is
the upper pressure die and H lower pressure die. When the heated overlaps of the
corrugated flue are required to be welded, an operator at the anvil lowers the lower
die H by means of the foot lever J for the end of the flue to be inserted, he then
raises the lower die H and by means of the hand lever L he draws the block M under
the lower die H as a kind of bed, the piston in cylinder A by the force of the steam
or other agent, puts the upper die G into close contact with the overlaps and the
pressure welds them together.
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 construction of the machine shown at Figures 1, 2, 3 and 4 of the annexed
drawings, in which the several parts are arranged for the successive operations of
feeding, crimping, or undulating, and then completely corrugating the parts so
crimped, as herein before described, the said crimping and corrugating being effected
by pressure dies, whereby the uniform thickness of the plate under operation is
maintained, all as set forth.
2. The appliance H in combination with the lower moving crimping die D¹ as
a combined gripper and feeder of plates to be corrugated, as set forth.
3. The means by which the simultaneous raising and lowering of corrugating
pressure dies D2, D3, for effecting the corrugation of metal plates, as set forth.
4. The means by which the upper pressure die D2 can be thrown out of action
when the corrugation of a plate has to be commenced at a distance from its end, the
lower die D³ then acting as a support for the plate, as described.
5. In an apparatus such as shown at Figures 5 and 6 of the annexed drawings, the
particular construction and arrangement of parts for bending corrugated plates into
cylindrical form, the means for adjusting the bending roll C to suit lengths of plates
for different diameters of flues, the appliances for enabling the bending roll to be
supported from one end only, also the appliances for freeing the opposite end to enable
the flue to be removed.
6. The particular construction and arrangement of trolly or carriage by which
cylindrical corrugated flues can be supported and moved to a furnace for the heating
of the overlaps, and to a machine for the roll welding or pressure welding, as
described with reference to Figures 7 and 8 of the annexed drawings.
7. The particular construction and arrangement of mechanism adapted for roll
welding of overlaps of corrugated cylindrical flues, as indicated at Figures 9, 10, and 11
of the annexed drawings.
8. The arrangement of appliances by which the overlap of cylindrical corrugated
flues can be welded by pressure, as represented at Figures 12 and 13 of the annexed
drawings.
The 19th day of March 1900
H. GARDNER,
Patent Agent, 166, Fleet Street, London, E.C., Agent for the said Douglas Dixon.