IMPROVEMENTS IN TOOLS FOR DRAWING OUT TUBES FROM MULTITUBULAR BOILERS, AND FOR EXTENDING TUBES
Year: 1881

page_text: LETTERS PATENT to William Clark Dixon, of Basingstoke, in the County of
Hants, Engineer, for an Invention of "IMPROVEMENTS IN TOOLS FOR DRAWING
OUT TUBES FROM MULTITUBULAR BOILERS, AND FOR EXTENDING TUBES."
PROVISIONAL SPECIFICATION left by the said William Clark Dixon at
the Office of the Commissioners of Patents on the 16th June 1881.
WILLIAM CLARK DIXON, of Basingstoke, in the County of Hants, Engineer.
"IMPROVEMENTS IN TOOLS FOR DRAWING OUT TUBES FROM MULTITUBULAR
BOILERS, AND FOR EXTENDING TUBES."
This Invention has for its object improvements in tools for drawing out tubes
from multitubular boilers and for extending tubos.
For drawing out tubes from multitubular boilers I employ a long rod of iron or
steel which is passed through the tubes to be drawn, and projects from both its
ends.
A cylindrical head or mandril of somewhat smaller diameter than the tube to be
withdrawn, and having a hole bored into it from one of its ends, is placed on to
one end of the rod, this end of the rod being somewhat reduced in diameter to fit
the hole. A slot is cut through the head or mandril and through the rod, and a
cotter is driven into the slot to key the mandril and rod firmly together. At that
end of the mandril into which the rod enters tho mandril is reduced in diameter in
two steps; on to the step of the larger diameter is placed a ring or collar. This
collar is of a diameter large enough to allow of its edge bearing against the end of
the tube to be withdrawn, but small enough to pass through the hole in the tube
plate. On to the exterior of the smaller step is screwed a nut to hold the collar on
to the mandril. The head of the mandril is tapered off, and should be of steel or
steel faced, to allow it to bear the blows of a sledge hammer.
Collars of various diameters aro provided to allow of the tool being used for
withdrawing tubes of different sizes.
At the smoke box end of the boiler the opposite end of the long rod has a screw
thread cut upon it; on to this is screwed a nut; the nut when screwed on to the
[Price Gd 1

page_text: rod is caused to bear against a block which rests against the edges of two short
parallel bars. These bars are rivetted together parallel with one another, and with
a space between them, and at their ends they are secured by clamps to the edge of
the smoke box in such a position that the space between the bars is in a line with
the row of tubes which are to be withdrawn. The long rod passed through one or
other of these tubes also passes through the space between the two bars above
mentioned. When the nut is screwed up on to this end of the long rod, it comes
against the block and presses it against the two parallel bars which form a bridge
for the block to rest against, the head on the opposite end of the long rod is thereby
drawn tightly against the opposite end of the tube which is to be withdrawn. By
this means the long rod is somewhat stretched, and a slight blow on the end of the
head, together with the tension on the rod, is sufficient to start the tube. The nut
is then screwed in a little, and the operation is repeated. By this means the tube
is quickly drawn out as far as the bridge. The time occupied in drawing the
tubes by this plan is much less than heretofore, aud the tubes are withdrawn
without injury, whereas by the plan heretofore adopted the tubes were frequently
injured by the operation of withdrawing them.
For the most part boiler tubes which require to be withdrawn are weakened
close up to the tube plates, and if the weak end is cut off and the tube lengthened
to bring it to its former length, it can be again used. To effect this lengthening of
a tube I employ a tool composed like the former one, of a long rod to be passed
through the tube, and with a screw thread cut at one end of it. This screw is
made to screw through a block which is secured by a clamp to one end of the tube,
whilst the opposite end of the rod bears against another block similarly secured to
the opposite end of the tube. The screw rod is turned by a handle secured to its
end, and the opposite end of the rod is thereby thrust against the block at the
opposite end of the tube; the tube is then made hot in one or more places, and the
rod is again screwed up.
By this means the tube can be stretched with the greatest case to the required
length.
Each of the blocks is turned so that the greater part of its length shall fit loosely
in the inside of the ends of the tube to be lengthened. A ring or shoulder is left
projecting around the block for the end of the tube to rest against. Around the
exterior of the remainder of the end of the block, which is left projecting from the
end of the tube, a screw thread is cut. A steel collar is screwed on to this screw
thread, the collar has a cylinder of steel projecting from its end; this cylinder
passes freely over the exterior of the end of the tube to be stretched. Around the
interior surface of the cylinder are formed a number of pointed teeth like ratchet
teeth, and lengthwise of the cylinder a number of slits are cut to divide it into a
number of spring fingers. The end of the cylinder is embraced by a clump, which
by means of a screw can be tightened up upon it, and the several spring fingers
thereby caused to grip and hold firmly on to the exterior of the tube.

page_text: SPECIFICATION in pursuance of the conditions of the Lotters Patent filed by
the said William Clark Dixon in the Great Seal Patent Office on the
16th December 1881.
WILLIAM CLARK DIXON, of Basingstoko, in the County of Hants, Engineer.
"IMPROVEMENTS IN TOOLS FOR DRAWING OUT TUBES FROM MULTITUBULAR
BOILERS, AND FOR EXTENDING TUBES."
This Invention has for its object improvoments in tools for drawing out tubes
from multitubular boilers and for extending tubes.
For drawing out tubes from multitubular boilers I employ a long rod of iron
or steel which is passed through the tubes to be drawn, and projects from both its
ends.
A cylindrical head or mandril of somewhat smaller diameter than the tube to be
withdrawn and having a hole bored into it from one of its ends, is placed onto one
end of the rod, this end of the rod being somewhat reduced in diameter to fit the
hole. A slot is cut through the head or mandril and through the rod, and a cotter
is driven into the slot to key tho mandril and rod firmly together. At that end
of the mandril into which the rod enters the mandril is reduced in diameter in two
steps; on to the step of the larger diameter is placed a ring or collar. This collar
is of a diameter large enough to allow of its edge bearing against the end of the
tube to be withdrawn, but small enough to pass through the hole in the tube plate.
On to the exterior of the smaller step is screwed a nut to hold the collar on to tho
mandril. The head of the mandril is tapered off and should be of steel, or steel
faced to allow it to bear the blows of a sledge hammer.
Collars of various diameters are provided to allow of the tool being used for
withdrawing tubes of different sizes.
At the smoke box end of the boiler the opposite end of the long rod has a screw
thread cut upon it, on to this is screwed a nut; the nut when screwed on to the
rod is caused to bear against a block which rests against the edges of two short
parallel bars. These bars are rivetted together parallel with one another and with
a space between them, and at their ends they are secured by clamps to the edge of
the smoke box in such a position that the space between the bars is in a line with
the row of tubes which are to be withdrawn. The long rod passed through one
or other of these tubes also passes through the space between the two bars above
mentioned. When the nut is screwed up on to this end of the long rod it comes
against the block and presses it against the two parallel bars which form a bridge
for the block to rest against, the head on the opposite end of the long rod is
thereby drawn tightly against the opposite end of the tube which is to bo
withdrawn. By this means the long rod is somewhat stretched, and a slight blow
on the end of the head together with the tension on the rod is sufficient to start
the tube. The nut is then screwed in a littlo and the operation is repeated. By
this means the tube is quickly drawn out as far as the bridge. The time occupied
in drawing the tubes by this plan is much less than heretofore, and the tubos are
withdrawn without injury, whereas by the plan heretofore adopted the tubes were
frequently injured by the operation of withdrawing them.
For the most part boiler tubes which require to be withdrawn are weakened
close up to the tube plates, and if the weak end is cut off and the tube lengthened
to bring it to its former length, it can be again used. To effect this lengthening of
a tube I employ a tool composed like the former one of a long rod to be passed
through the tube, and with a screw thread cut at one end of it. This screw is
made to screw through a block which is secured by a clamp to one end of the tube,
whilst the opposite end of the rod bears against another block similarly secured

page_text: to the opposite end of the tube. The screw rod is turned by a handle secured to
its end, and the opposite end of the rod is thereby thrust against the block at the
opposite end of the tube; the tube is then made hot in one or more places, and the
rod is again screwed up. By this means the tube can be stretched with the
greatest case to the required length.
Each of the blocks is turned so that the greater part of its length shall fit loosely
in the inside of the ends of the tube to be lengthened. A ring or shoulder is left
projecting around the block for the end of the tube to rest against. Around the
exterior of the remainder of the end of the block, which is left projecting from the
end of the tube, a screw thread is cut. A steel collar is screwed on to this screw
thread, the collar has a cylinder of steel projecting from its end; this cylinder
passes freely over the exterior of the end of the tube to be stretched. Around the
interior surface of the cylinder are formed a number of pointed teeth like ratchet
teeth, and lengthwise of the cylinder a number of slits are cut to divide it into a
number of spring fingers. The end of the cylinder is embraced by a clamp which
by means of a screw can be tightened up upon it, and the several spring fingers
thereby caused to grip and hold firmly onto the exterior of the tube.
In order that my said Invention may be most fully understood and readily
carried into effect. I will proceed to describe the Drawings hereunto annexed.

page_text: rings which are tightened by screw and
working through one of the blocks, and
There is a hole in one of the blocks
firmly held from turning.
to
nut over the fingers; o is a screwed rod
abutting at its end upon the other block.
receive a bar by which the block can be
The tube to be stretched has the rod o passed down the centre, and the blocks k
fastened on.
When the tube is held as described, the rod o is turned by means of the handle
shewn in Figure 7, and the tube is heated to a dull red in a fire; the tube is thus
very readily stretched. The screw is turned from time to time until the required
length is attained.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I claim,-
First. The combination illustrated by the Figures 1, 2, 3, and 4, consisting of
the screwed rod a, the detachable head or mandril c, the collar e, the screw nut g,
and a suitable abutment h, the whole constituting my improved tool to be operated
by percussion applied after strain has been put on by the screw, substantially as
described.
Second. The combination illustrated by the Figures 5, 6, and 7, consisting of
blocks, clamps, and screwed rod, whereby when the blocks and clamps have hold
of the ends of the tube they are separated, the tube being heated to facilitate its
elongation, substantially as described.
In witness whereof, I, the said William Clark Dixon, have hereunto set my
hand and seal, this Thirteenth day of December, in the year of our Lord
One thousand eight hundred and eighty one.
W. C. DIXON. (L.S.)