IMPROVEMENTS IN TOOLS FOR EXPANDING BOILER AND OTHER TUBES."
Year: 1880

page_text: LETTERS PATENT to William Thorburn, of Luton, in the County of Beds, for
an Invention of "IMPROVEMENTS IN TOOLS FOR EXPANDING BOILER AND
OTHER TUBES."
PROVISIONAL SPECIFICATION left by the said William Thorburn at the
Office of the Commissioners of Patents on the 14th September 1880.
WILLIAM THORBURN, of Luton, in the County of Beds.
TOOLS FOR EXPANDING BOILER AND OTHER TUBES.".
"IMPROVEMENTS IN
One form of my improvement consists in the use of 3, 4, or more metal
conical expanding rollers, usually made of steel, and made to work in a cylindrical
mandril or stock for inserting in the end of the tube to be expanded. The
cylindrical mandril has slots cut through its sides except a short distance at its
The slots are made
inner end; in these slots the conical expanding roller works.
so that the expanding rollers may be placed in position from the outside of tho
cylindrical mandril to be acted on by a central cone or expanding mandril herein-
after more fully described. When the mandril is in the tube the larger diameter
of the conical rollers are usually placed in the mandril or stock to extend inward
and the smaller diameter outward, but the smaller diameter may extend inward
and the larger outward if desired; they will answer equally well in both positions.
When the expanding rollers are in position for acting on the end of the tube for
expanding and fitting it to the boiler plate, the outer circumference of the
expanding rollers are parallel, or they may be made to form a slight taper if desired
instead of a parallel diameter. By using them when they form a parallel diameter
it retains the interior of the tube parallel when acted on by the expanding roller,
and ensures a good and uniform fit of the tube to all parts of the boiler plate.
This is one of the special advantages of my improvement, to set or fit the tube
uniformly to all parts of the tube opening in the boiler plate, making no difference
what thickness of boiler plate is used. Heretofore all expanding mandrils as far
as I know for expanding and setting boiler tubes have been provided with tapering
drifts or mandrils for acting on the expanding rollers, the use of which necessarily

page_text: expands the ends of the tubes more than other parts, and which more or less
prevents an uniform fit of the tube end to the whole thickness of the boiler plate.
The outer end of the cylindrical mandril is provided with a flange extending a
short distance from the outer circumference of it, and provided with a screw. The
slots for receiving the small ends of the expanding rollers are cut through the
flange on the end of the mandril or stock, and after the rollers are placed in
the slots they are retained in position by a screwed cap, plug, or central flange made
of brass or other metal for screwing to the outer end of the stock. The expanding
rollers have sufficient lateral play given for moving inward and outward from the
centre of the cylindrical mandril for acting on and expanding the tube.
The retaining cap on the end of the stock is provided with a central conical
expanding mandril made about the same taper of the expanding rollers; this
central mandril is usually made to pass through a screwed bush bolt working in
the centre of the retaining cap, and this bush bolt acts on the central expanding
mandril for forcing it against the sides of the expanding rollers for acting on the
inside of the tube for expanding and forcing it outward to fit the boiler plates or
for other purposes.
When the expanding rollers are set out against the end of the tube the whole
aparatus is turned round, while in the end of the tube, by means of a ratchet
or any other known form of lever for uniformly acting on the end of the tube
for expanding and fitting it to the boiler plate. The central expanding cone
acting on the expanding roller may be set up during the process of turning the
apparatus round in the end of the tube-until-the-tube-is-sufficiently-expanded,
seated, and fitted-to-the-boiler-plates. ―
The accompanying Drawings show several additional modifications of my
improvements. Fig. 1 is a longitudinal sectional view of the apparatus in one
modification showing the cylindrical mandril or stock A' and the expanding
mandril A for drawing outward, for forcing the expanding roller B against the
tube C for expanding the tube to fit the boiler plate D. Fig. 2 is a longitudinal
sectional view of another modification of the apparatus showing the expanding
mandril or cone piece A being forced inward by the set screw a against the conical
rollers B for expanding the tube to fit the boiler plate D. Fig. 3 is another modi-
cation of the apparatus in which the expanding rollers B are made parallel, or that
portion of them that acts on the tube in the process of expanding it; in this case,
the bearing ends of the rollers B are made conical and revolve in flanges or
plates E, E, in suitable conical recesses as represented in Fig. 3. By drawing the
plates E, E, together by the screw bolt A the expanding rollers B, B, are forced
out by reason of their conical end bearings against the inner surface of the tube C
and thereby expands the tube C to fit the plate D as in the other modifications
before described.
In this modification of my improvement there is a guide plate g attached to the
centre of the bolt A for retaining the expanding rollers B, B, in a parallel position.
Fig. 4 is another modification of the improvement showing another mode of
drawing the flanges E, E¹, together by a right and left hand screw bolt A; in this
case the ends of the expanding rollers have an inward bearing or conical
pieces d, d, through which the bolt A passes, it is likewise supplied with a guide
piece g attached to the bolt A for keeping the expanding rollers B, B, in a parallel
position.
In all the modifications of the apparatus shown, four expanding rollers are
represented, but for the large size tubes five, six, or moro rollers may be employed
with practical advantage. It is obvious to any one skilled in the art that the
principle of my improvement may be applied in a number of modified forms, all of
which would be quite capable of expanding the tubes, as any of the plans of the
apparatus herein described and represented by the Drawings.
In making the expanding rollers B, B, the taper given to them should be
sufficient to give the required amount of expansion or lateral movement for setting

page_text: the tubing to the boiler plate by one operation. By forcing out the expanding
mandrils or cone pieces with screws, all jarring and concussion is avoided by driving
a tapering drift between the expanding rollers. However, I do not confine myself
to the use of screws for forcing out the expanding rollers; cutters may be used to
act by screws for that purpose by passing the cutter through the collar end of the
outer flange E and the end of the cone mandril bolt A, sufficient draft being
given to the cutters to move the expanding rollers the required distance in or out
of the mandril.
•
However, I prefer the use of screws to any other known method of acting on the
expanding rollers as being cheaper and less liable to injure the apparatus and tubes
in the process of expanding and fitting them to the boiler plates, or for other
purposes for which the improvements can be employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Thorburn in the Great Seal Patent Office on the 12th March
1881.
WILLIAM THORBURN, of Luton, in the County of Beds.
TOOLS FOR EXPANDING BOILER AND OTHER TUBES."
"IMPROVEMENTS IN
The object of my improvement is to make an expander for uniformly fitting the
tube to any thickness of boiler plate to avoid the use of hammering or driving
tapering drifts, and consequently all concussion and jarring of the tube in the
process of expanding and fitting it to the plate is obviated.
Fig. 1 of the accompanying Drawings is a longitudinal section of the apparatus,
also a transverse section showing one modification of my improvement, which
consists in the use of three, four, or more metal conical expanding rollers B, usually
made of steel, and inade to work in a cylindrical mandril or stock E for inserting
in the end of the tube C to be expanded. The cylindrical stock E has slots g cut
|_ through its sides except a short distance at its inner end; in these slots the conical
expanding rollers B, B, work. The slots g are made so that the expanding rollers B
may be placed in position from the outside of the cylindrical stock E, to be acted
on by a central-cone-or-expanding_mandril_A, hereinafter more fully described.
_ When_the_stock E is in the tube the larger diameter of the conical rollers Barc
usually placed in the stock to extend inward, and the smaller diameter outward.;
but the smaller diameter may extend inward and the larger outward if desired,
they will answer oqually well in both positions. When the expanding rollers B
are in position for acting on the end of the tube C for expanding and fitting it to
the boiler plate D. The outer circumference of the expanding rollers Bare parallel,
or they may be made to form a slight taper, in either direction, if desired; instead
of a parallel diameter it retains the interior of the tube parallel when acted on by
the expanding roller, and insures a good and uniform fit of the tube to all parts of
the boiler plate. This is one of the special advantages of my improvement to set
or fit the tube C uniformly to all parts of the tube opening in the boiler plate D,
making no difference what thickness of boiler plate is used; heretofore all
expanding mandrils, as far as I know, for expanding and setting boiler tubes, have
been provided with tapering hammering drifts or mandrils for acting on the
expanding rollers, the use of which necessarily expands the ends of the tubes more
than other parts; and which more or less prevents an uniform fit of the tube end
to the whole thickness of the boiler plate, and in some cases causes the ends of the
tubes to split. The outer end of the cylindrical stock E is provided with a flange c,
extending a short distance from the outer circumference of it, and provided with a
screw. The slots g for receiving the small ends of the expanding rollers B are
usually cut through the flange on the end of the stock E, and after the rollers aro
placed in the slots g they are retained in position by a screwed cap, plug, or central
flange, made of brass or of other metal for screwing to the outer end of the stock.
The expanding rollers B have sufficient lateral play given for moving inward and
outward from the centre of the stock E for acting on and expanding the tube C.
The retaining cap f on the end of the stock is provided with a central conical
expanding mandril A, made about the same taper as the expanding rollers B; this
central mandril is usually made to pass through a screwed bush bolt h working in
the centre of the retaining cap S, and this bush bolt acts on the central expanding
mandril A for forcing it against the inner sides of the expanding rollers B, for
acting on the inside of the tube for expanding and forcing it outward to fit the
boiler plates D or for other purposes. When the expanding rollers are set out
against the end of the tube the whole apparatus is turned round while in the end
of the tube by means of a ratchet lever, Figs. 9 and 10, or any other form

page_text: of lever for uniformly acting on the end of the tube for expanding and fitting it
to the boiler plate. The central expanding cone A acting on the expanding roller
may be set up during the process of turning the apparatus round in the end of the
tube C until the tube is sufficiently expanded, seated, and fitted to the boiler
plate D.
Another modification of my improvement is represented by Fig. 2, showing a
longitudinal section of the expanding apparatus, also a transverse sectional plan.
In this modification the expanding mandril or cone piece A is made for drawing
outward by a screw nut on the end of the mandril as represented, for forcing the
expanding rollers B against the tube C for expanding it to fit the boiler plate D;
it also shows the large end of the expanding rollers B extending outward, which
may be placed in position by cutting slots through the sides of the stock E or from the
inside of the stock if desired, when the apparatus is placed in the ends of the tubes
and expanding rollers forced out for working it is turned around by means of a
lever in the manner before stated in referring to Fig. 1. In this plan of the
expander provision is made for allowing the end of the tube to extend out /, of an
inch more or less beyond the boiler plates, as represented, the Drawing is sufficient,
full, and plain to show the working of this modification of the expander without
further specifying the same.
Fig. 3 is another modification of the improvement, showing a longitudinal section
of the apparatus, also a transverse sectional plan. The expanding mandril or cono
piece A is forced inward by the set screw a tagainst the expanding rollers B, B,
for expanding and fitting the tube to the boiler plate D, as fully represented by the
Drawings.
Fig. 4 is another modification of the apparatus, in which the expanding rollers B
are made parallel, or that portion of them that acts on the tube in the process of
expanding it. In this case the bearing ends of the rollers B are made conical, and
revolve in discs E, E', in suitable conical recesses, as represented in Fig. 4. By
forcing or drawing the discs E, E¹, together by the screw bolt A the expanding
rollers B, B, are forced out by reason of their conical end bearings against the
inner surfaces of the tube C, and thereby expands the tube C to fit the plate D, as
in the other modification before described. In this modification of my improve-
ment there is a guide plate g attached to the centre of the bolt A for retaining the
expanding rollers B, B, in a parallel position.
Fig. 5 is another modification of the improvement showing another mode of
drawing the discs E, E¹, together by a right and left hand screw bolt A. In this
case the ends of the expanding rollers have an inward bearing on conical pieces d, d,
through which the bolt A passes. It is likewise supplied with a guide piece g
attached to the bolt A for keeping the expanding rollers B, B, in a parallel
position.
Fig. 6 represents a modification of the apparatus shown in Fig. 2, the difference
being the flange fin Fig. 6 forms part of the stock E, and the stock is supplied
with a central cap or sleeve h for receiving the bolt portion of the conical expanding
mandril A, as represented, for acting on the expanding rollers B, B. In this arrange-
ment the end of the tube C is allowed to extend through the boiler plate one quarter
of an inch, more or less. The expanding rollers B, B, may be placed in position
in the stock E by slots cut therethrough large enough for passing the entire roller
through; or the expanding rollers may be placed in position from the inside of the
stock E. In this case the slots cut in the side of the stock E are only made
sufficiently large to allow a portion of the roller to extend through the stock for
acting on the tube C in the process of expanding, and fitting it to the boiler
plate D.
Fig. 7 is a modification of the apparatus shown in Fig. 3. The only difference
between the two arrangements is, one is made (Fig. 7) for expanding and setting
the tube C to the plate with its end flush with the boiler plate D, as represented.
In other respects the two arrangements are substantially the same.
Fig. 8 is another modification of the apparatus represented in Fig. 3, by making

page_text: the flange e attached to the upper part of the stock E of less diameter and width,
as shown by the Drawings.
Figs. 9 and 10 show the manner of attaching a ratchet lever to the apparatus for
working or turning it in the tube in the process of expanding said tube. In some
cases an ordinary spanner wrench will serve the purpose of working the apparatus
by taking hold of the cap f. In all the modifications of the apparatus shown four
expanding rollers are represented, but for the large sized tubes five, six, or more rollers
may be employed if desired. It is obvious to anyone skilled in the art that the
principle of my improvement may be applied in a number of modified forms, all of
which would be quite capable of expanding the tubes as any of the plans of the
apparatus herein described and represented by the Drawings. In making the
expanding rollers B, B, the taper given to them should be sufficient to give the
required amount of expansion or lateral movement for setting the tubing to
the boiler plates in one operation. By forcing out the expanding mandrils or cone
pieces A with screws all jarring and concussion is avoided by driving a tapering
drift between the expanding rollers. However, I do not confine myself to the use
of screws for forcing out the expanding rollers, cutters may be used to act by
screws for that purpose by passing the cutter through the collar end of the outer
flango E or fand the end of the cone inandril bolt A, sufficient draft being given
to the cutters to move the expanding rollers the required distance in or out of tho
mandril. However, I prefer the use of screws to any other known method of
-acting on the expanding rollers as being cheaper and less liable to injure the
apparatus and tubes in the process of expanding-and-fitting-them-to-the-boiler
plates, or for other purposes-for-which-the-improvement.can be employed.
Having now described the construction and mode of working my improvement,
what I claim as new is,-
1st. In a tube expander the tapering expanding rollers B, B, Fig. 1, mado to
work in a stock. E, so that a central expanding mandril or cone can be made to
act on their inner diameters for forcing said expanding rollers against the inner
diameter of the tube C in the manner and for the purposes hereinbefore described
and represented.
.
2nd. In a tube expander the manner of setting or forcing out the tapering
expanding rollers B, B, by the central conical expander A, as and for the purposes
herein before described and represented.
3rd. In a tube expander the combination of the stock E, tapering expanding
rollers B, B, and central conical expander A, as and for the purpose described and
represented.
In witness whereof, I, the said William Thorburn, have hereunto set my hand
and seal, this Eighth day of March, in the year of our Lord One thousand
eight hundred and nighty one