Improvements in or Applicable to Tubes for the Generation of Steam in Boilers.
Year: 1889

page_text: Date of Application, 2nd Aug., 1889
Complete Specification Left, 1st May, 1890-Accepted. 7th June. 1890
PROVISIONAL SPECIFICATION.
Improvements in or Applicable to Tubes for the Generation of
Steam in Boilers.
I, ADAM SMITH of 7 New Writtle Street Chelmsford in the County of Essex
Engineer do hereby declare the nature of this invention to be as follows:-
My invention relates to tubes for all classes of steam boilers, and consists in
forming by any known or suitable method the said tubes into a spiral form of any
desirable number of sides or faces, and of any desirable pitch.
At any distance from each end I swell the tube and in doing so merge the spiral
into cylindrical form, (for convenience of fastening into the tube plates of boiler), the
outside diameter of this cylinder being greater than the greatest diameter of the
spiral.
Dotad thin
1000
loted this 1st
1st day of August 1889.
COMPLETE SPECIFICATION.
Improvements in or Applicable to Tubes for the Generation of
Steam in Boilers.
I, ADAM SMITH late of 7 New Writtle Street, Chelmsford, in the County of Essex,
but now of 29 Glebe Place, Kings Road, Chelsea, in the County of Middlesex,
Engineer, do 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 :-
My invention for improvements in or applicable to tubes for the generation of
steam in boilers has for its object to construct tubes for steam boilers so that when
fixed in the boiler between the tube plates they shall be capable of independent
expansion and contraction, and of increased strength and with larger heating surface;
and consists of a steam boiler tube having cylindrical ends and formed into a spiral
shape, having any suitable pitch and any desirable number of faces, between the said
ends, the size of the ends or of one end being such that the said spiral portion of
the tube will readily pass through the hole in the tube plate made to receive the
said end.
The accompanying drawing shews a steam boiler tube constructed according to
my invention.
The tube consists of the cylindrical ends a b and an intermediate or central portion c
formed into a spiral shape of any suitable pitch and any desirable number of faces.
The size of the end a or bor of both ends a b relatively to that of the central
portion c is such that the said central portion will readily pass through a hole of the
size of said end or ends. The faces may be either convex or concave; they are shown
convex to the axis.
The tube may be formed by any suitable method. A convenient method consists
in passing a cylindrical tube through a die of the desired shape and in rotating the
said tube as it passes through the dies. The tube is then cut into the desired lengths
and the ends swelled into a cylindrical form.
In another method a tube having the desired number of sides or faces may be
twisted to a suitable spiral shape and the ends swelled as above.
Having now particularly described and ascertained the nature of my said inven-
ion and in what manner the same is to be performed, I declare that what I
laim is:
A boiler tube having cylindrical ends and an intermediate or central spiral part of

page_text: any suitable pitch and any desirable number of sides, the size of one end being such
that said central part will readily pass through a hole formed to receive the said end,
substantially as described.
2. A boiler tube constructed substantially as described with reference to the
drawings.
DJ
1000