or Apparatus therefor.
Year: 1886

page_text: or Apparatus therefor.
I, WALLACE FAIRWEATHER C.E. of the firm of Cruikshank and Fairweather,
Glasgow, Lanarkshire, Fellows of the Institute of Patent Agents, do hereby declare
the nature of this invention and in what manner the same is to be performed (as
communicated to me from abroad by The Babcock and Wilcox Company, of New
York City, in the United States of America, Steam Boiler Manufacturers,) to be
particularly described and ascertained in and by the following statement:-
This invention relates to the forming of serpentine tubes of rectangular shape.in
cross section, from round welded pipe, for use chiefly as headers in sectional steam
boilers, and it comprises an improved method of forming such serpentine tubes
and machinery or apparatus specially designed for that purpose.
In the accompanying drawings which illustrate the invention figure 1, sheet 1,
is an end elevation, figure 2 a side elevation, and figure 3 a plan view of a machine
with which the improved method may be practised. Figures 4 and 5 are side and
transverse views respectively of the blank and figures 6 and 7 side, end and plan
views of the completed tube.
Figure 1 sheet 2 is a side elevation. Figure 2 an end view. Figure 3 & cross-
section, showing a round pipe blank and relative position of the parts of the
machine ready for squaring the blank. Figure 4, a cross-section of the same,
showing the round tube formed into a polygonal blank, and the relative position of
the parts of the machine, after the completion of the operation. Figures 5 and 6,
side and end views of the completed header, after it has passed through the
operations of squaring, forming and punching, and with an end welded in to receive
the end connection. Figures 7 and 8, side and plan views of the mandrel.
Figures 9 and 10, enlarged side and end views of the mandrel spreading device.
Figures 11 and 12, enlarged side and end views of the corrugated tube and the
parts of the mandrel; and Figures 13, 14, 15, 16, 17, 18, 19, 20 and 21 enlarged
views of the various parts of the mandrel. Figure 22 shows a sectional mandrel
for squaring tubes.
The improved method of forming serpentine tubes consists in first subjecting a
cylindrical pipe or blank (shown in Fig. 5 sheet 1,) to compression between upper
and lower dies as shown in Figs. 1 and 2, so as to produce an oblong form in cross-
section as shown in Fig. 4, and then by means of side dies to further compress the
blank into the serpentine form shown in Figs. 6 and 7.
By this method no square corners are formed and the metal needs only to be
rearranged once instead of twice as heretofore practised.

page_text: 4
:
The machine employed in this operation and which is represented in sheet 1 of
the drawings consists of the upper and lower dies a, a¹, and side dies b, b; which
are mounted on a suitable frame work, and may be operated by means of hydraulic
plungers as shown, or by other well known means. The upper and lower dies a, a¹,
are constructed with plain faces and act to compress the cylindrical blank c, to the 5
oblong form in cross section, as shown at d, Fig. 4, the lower die a', being fixed or
stationary, and the upper die a, movable.
The side dies b, b, are constructed with transverse depressions upon their acting
faces, as shown in Fig. 3, that form corresponding depressions in the sides of the
blank when operated, and produce the serpentine tube shown in Fig. 7, the action 1
of the side dies b, b, following the operation of the upper and lower dies a, a¹, that
remain compressed and retain the blank, until the action of the side dies is
completed. A sectional or jointed mandrel corresponding in form to the depressions
in the dies, is used to act in conjunction therewith as hereinafter described.
In the machine shown in sheet 2 of the drawings, A, represents a frame work, 1
supporting dies or formers B, B, constructed with longitudinal working faces of
serpentine form, or B', B¹, with flat working faces.
These dies are made capable of vertical movement, and in the present instance,
are connected to cross beains C, C.
The upper cross beam is adjusted vertically by means of the nuts a, a, upon the
threaded standards of the frame A, as shown. The lower cross-beam is fitted to
slide vertically upon said standards, and rests upon a sliding plunger D, operated
by an hydraulic press, or by other suitable means.
The dies B, and B¹, are grooved, as shown at b, in which sliding plates d, d, are
arranged, said plates being held in position by the screws e and e, so as to allow a
vertical movement in said grooves.
I, is a section of a square mandrel employed to square the blank upon, which
mandrel is by preference made in sections, and capable of contraction and expansion,
by a longitudinal movement of one section upon the other, the respective sections
being constructed with inclined bearing surfaces to effect such purpose as shown in
Fig. 22.
The sectional mandrel H, for corrugating the square blank, is composed of
separate blocks h, arranged within a framework, Fig. 9, and is held in position by
the rod m, passing through the sections, this rod being removed after the mandrel
is placed within the squared blank g.
The frame of the mandrel is composed of two parts, k, k¹, the part k, being
arranged within the part k¹, and made capable of a longitudinal movement, by
means of the hand screw o, the parts being held together, and in place, by the
bolts i, that pass through elongated slots v, in the part k, and the loose key-piece Z.
Upon adjacent sides of the parts k, k¹, a series of cams u, and corresponding
depressions are provided for the purpose of separating the same by a longitudinal
adjustment of the part k.
The blocks h, are composed of separate parts, l; p, q, r, s, shown detached and
enlarged in Figs. 13 to 20 of the drawings.
Such parts are constructed in substantially the form shown, and are relatively
. assembled to form the block h, as shown in Figs. 1, 2, 7, 8, 12, 13 and 14.
These blocks h, are rounded on their working faces to conform to the corresponding
depressions in the dies B, and the various parts of which they are composed are
made in such shape or contour that when pressure is applied, the inclined contact
surfaces force the parts firmly against the sides of the blank.
The operation of the machine is as follows:-
The dies, B¹, B¹, are separated as shown in Fig. 3, and a blank g, of cylindrica
- form placed between them and the side plates d, d.
A square mandrel I, is then introduced into the interior of the blank, as shown
in Fig. 3, and the dies B¹, B¹, having flat parallel surfaces, then compressed thereon
which changes the form of the blank to a polygonal shape in cross-section as show
in Fig. 4, two of the faces of the header being formed by pressure.exerted betwee

page_text: the faces of the dies and the enclosed mandrel; the two opposite sides being formed
by the pressure of the pipe against the sliding abutments d, d.
The dies B, B¹, are then relaxed, the mandrel I, removed, and the sectional
mandrel H, substituted, as shown in Figs. 1 and 2, and the dies B, B, substituted
for B¹, B¹.
The blocks being now supported by the blank g, the part k, of the mandrel is
moved longitudinally by the hand screw o, which, by means of the cam faces u,
separates or spreads the sides k¹, firmly against the adjacent sides of the blank g,
and through the inner wedge pieces p, p, forces the faces of each of the movable
blocks forming the mandrel against the two opposite sides and locks them in
position. The suspension rod m, is then withdrawn to allow of cross-movement
of the blocks h.
The dies B, B, are now advanced, together, the projecting portion of their
working faces acting in contact with the faces of the respective adjacent block h,
which force the blank into the opposite corresponding depressions in the dies and
produce the completed serpentine blank, as shown in Fig. 11.
The part , of the mandrel, is now relaxed by turning back the hand screw o,
which brings the cam faces u, within the corresponding adjacent recesses in the
part, and permits its withdrawal, the end piece Z, dropping ont; the side plates p,
of the blocks, h, being thereby relieved, which, in turn, release the other parts, and
the sectional blocks may be dropped out in pieces.
The lies, B, B, are now returned to their open position when the mandrel may.
be re-assembled ready for a repetition of the operation.
°
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me, I declare that what I claim is:-
(1.) The method of making serpentine tubes which consists in first compressing
cylindrical tube to an oblong form in cross-section and subsequently forming
transverse depressions therein as described.
(2.) A inachine for forming tubes or blanks of polygonal form in cross-section,
consisting of a pair of dies joined together by sliding abutments in combination
with a sectional mandrel.
(3.) A machine for forming serpentine headers or tubes of polygonal form in
cross section, consisting of a pair of working dies having their acting faces
5 constructed with transverse depressions and a mandrel composed of movable
sections corresponding to the depressions in the dies, said sections being made in
separable parts, substantially as described.
(4.) In a machine for forming serpentine headers or tubes, the combination of a
pair of working dies having their acting faces constructed with transverse
O depressions, and a sectional mandrel provided with a series of separate blocks,
corresponding to the depressions in the dies and capable of a transverse movement
in the same plane, said mandrel also containing an adjusting device for spreading
out against the plain sides of the blank.
(5.) A sectional mandrel for the purpose set forth, having a series of blocks
5 composed of separable parts, constructed with wedging contact surfaces, whereby
said parts are expanded and forced against the adjacent surfaces of the blanks, by
the pressure of the external dies.
Dated this Second day of March 1886.
CRUIKSHANK & FAIRWEATHER,
Agents.