Improvements in the Manufacture of Tubes for Boilers and other like Purposes.
Year: 1888

page_text: Date of Application, 8th Feb., 1888
Complete Specification Left, 8th Nov., 1888
Complete Specification Accepted, 21st Dec., 1888
Improvements in the Manufacture of Tubes for Boilers and other
like Purposes.
I, SAMUEL EARNSHAW HOWELL, of Brook Steel Works Sheffield in the County of
York Steel Tube Manufacturer do hereby declare the nature of this invention to be
as follows:
This invention of improvements in the manufacture and construction of tubes such
as are used for example in Locomotive boilers and other like boilers, has for its object
to preserve the ends of the tubes next the fire box, from the severe scouring action of
particles of fuel carried forward by the strong draught, and the action of the flame,
upon the interior surface of the said tubes, as well as to lend support to them at
that part.
For this purpose I construct the body of the tubes which are usually of copper, of
the same outside diameter throughout, but at the end of the tube intended to be fixed
in the fire-box, I enlarge the internal diameter of the copper tube, for a suitable
distance, say for example, six to twelve inches.
This internal enlargement may be readily accomplished by making the mandril on
which the copper tube is drawn of a correspondingly enlarged diameter, I then place
a piece of steel tube inside the end of the copper tube so internally enlarged, and
complete the drawing of the copper upon the steel tube, thus causing the copper to
adhere very closely and firmly to the inserted length of steel tube.
Instead of forming an internal enlargement or chamber first, I may if I find it
desirable, place the steel tube inside a copper tube, and by drawing the latter upon a
mandril of rather smaller diameter than the said steel tube, I cause the copper during
that process to overlap the end of the steel tube, in a manner equivalent to the
enlargement above described.
Although I prefer to construct by either of the above methods, a shoulder in the
copper against which the end of the short steel tube will bear, I do not bind myself
to form such shoulder, but may simply draw the copper tube upon a steel or iron tube
for the purpose specified. I also wish it to be understood that although I have

page_text: mentioned tubes of certain metals in the foregoing description, being such as are
generally used for the purpose described, my invention may be applied to tubes of
other metals than those named.
In tubes constructed according to my invention the fierce heating of the flame from
the furnace or fire-box is received by the inserted steel tube, as well as the action of
particles of coke carried forward by the draught, and by reason of the greater
hardness and more obdurate nature of the steel in resisting the destructive action
above described, the life of the copper tube is considerably prolonged.
Doted the 7th day of Fahnu 1000
ROBT. F. DRURY,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Tubes for Bollers and other
like Purposes.
1, SAMUEL EARNSHAW HOWELL of Brook Steel Works, Sheffield in the County
of York, Steel Tube Manufacturer do bereby 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 of improvements in the manufacture and construction of tubes,
such for example as are used in the boilers of Locomotive Engines, and other tubular
boilers, has for its object to preserve the ends of the tubes that are open to the firebox
from the severe scouring action of particles of fuel carried forward by the draught,
and the corroding action of the fire upon the internal surface of the end of the said
tubes as well as to give increased strength to that particular part.
The method of carrying out my said invention is illustrated in the annexed sheet of
drawings in which
Fig. 1, is a longitudinal section of the end of a tube constructed according to my
invention.
Fig. 2, is the end view of same.
Similar letters of reference indicate similar parts in either of the figures.
In carrying out my invention, in the manner shown, I make the body of the tube
which is usually of copper, of the same outside diameter throughout, but at the end
which is to be fixed in the firebox, I enlarge the internal diameter of the said tube for
a suitable distance say for example six to twelve inches long.

page_text: The portion marked A represents the tube, and that marked B, represents the part
having its internal diameter enlarged.
This internal enlargement may be readily effected by making the mandril on which
the tube is drawn, of a correspondingly enlarged diameter; I then take a piece of
steel tubo C, place it inside the enlarged end of the copper tube, and complete the
drawing of the copper tube upon the steel tube, thus causing the copper to be shrunk
upon and consolidated with the steel tube or sleeve, so that practically there is a
perfect joint between the outer and inner tube or sleeve that is steam tight, rendering
caulking unnecessary.
Instead of enlarging the interior of the end of the tube as above described, I may
place the steel tube or sleeve inside the copper tube, and by drawing the latter upon
a mandril of rather smaller diameter than the steel sleeve, the copper is caused to
overlap the end of the steel sleeve in a manner equivalent to the beforementioned
enlargement.
Although by either of the above methods I form a shoulder at D, against which
the end of the steel sleeve C, abuts, I do not consider this formation as essential to
my invention, as the outer tube may be drawn upon the inner tube or sleeve in a
satisfactory manner without a shoulder being formed.
I wish it to be understood that although I have mentioned copper and steel as the
two metals employed, I do not confine myself to the use of these metals only, but
merely give them as examples for the purpose of illustration, and to show that a tube
of ductile and comparatively soft metal, should have a sleeve of harder and more
obdurate metal better enabled to resist the destructive action of the fire before described,
and to prolong the life of the softer tube.
Having therefore 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 :-
A metallic tube for steam boilers, and other like apparatus, having an end con-
structed with an internal tubular portion of hard metal and an external drawn
tubular portion of ductile metal, the latter fast upon and consolidated with the metal
of the former, as hereinbefore described, and as shown.
Duted the fith d
1 1000
ROBT. F. DRURY,
Agent for the Applicant.