Improvements in the Shells or Barrels of Locomotive and similar Boilers.
Year: 1888

page_text: Date of Application, 26th July, 1888
Complete Specification Left, 18th May. 1839-Accented, 22nd June, 1389
PROVISIONAL SPECIFICATION.
Improvements in the Shells or Barrels of Locomotive and similar
Boilers.
I, MARTIN ATOOK of Royal Canal House, Broadstone, Dublin, Engineer, do hereby
declare the nature of this invention to be as follows:-
This invention has reference to means for providing elasticity in the shells or
barrels of locomotive and similar boilers with the view to obviating undue strains
arising from expansion and contraction.
For this purpose the tube plate at the smoke box end, which may be of any suitable
metal, such as steel, iron or copper, is formed with a corrugated flange that may
either be arranged to turn inwards within the barrel of the boiler or may be reversed
and turned outward.
The flange may have one or more corrugations and the corrugated part may
either be entirely within the barrel or may project beyond the front tube plate. At
one or more of the circumferential joints the barrel is provided with two corrugated
rings there being at each joint so provided both an inner ring and an outer ring,
the inner one being made of copper or other non-corrosive metal, and having for
object not only to add strength to the joint but also to protect the outer ring from
pitting or other injury that might otherwise arise from contact with water. The
convex part or ridge of the inner ring may enter the annular concavity or channel
of the outer ring or the ridge of the inner ring may project inwardly instead of
outwardly.
COMPLETE SPECIFICATION.
Improvements in the Shells or Barrels of Locomotive and similar
Boilers.
I, MARTIN ATOOK, of Royal Canal House, Broadstone, Dublin, 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:
This invention has reference to means for providing elasticity in the shells or
barrels of locomotive and similar boilers with the view to obviating undue strains
arising from expansion and contraction.
In a paper by me on tubing of locomotive boilers read before the Institution of
Civil Engineers of Ireland April 5th 1882 I alluded to the evils chargeable to the
difference of expansion between the tubes and the boiler shell and stated that they
could be overcome by making the vertical joints of the barrel, or even one of them,
with a corrugated ring of iron or steel. Fig. 1 of the annexed drawings illustrates
an expansion ring as applied by me for the purpose mentioned in July 1882, to a
stationary boiler belonging to the Midland Great Western Railway Co. of Ireland.
Now according to my present invention the tube plate at the smoke box end which
may be of any suitable metal such as steel iron or copper is formed with a flange
having two or more circumferential corrugations, and which may either be arranged
to turn inwards within the barrel of the hoiler or may be reversed and turned
outward. By making the flange with two or more corrugations I increase the life
of this part of the boiler. The constant working (due to expansion and contraction)
that takes place on the inside of such corrugations tends to grooving and this is
minimised by dividing the movement over two or more corrugations. The corrugated
D
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page_text: part is either entirely within the barrel or a part of it may project beyond the front
tube plate. The arrangement of the whole tube plate and flange entirely within the
barrel is advantageous in a Multifubular Locomotive Boiler because it allows the
front plates of the barrel itself to be carried forward for attachment to framing and
cylinders in a Locomotive Engine as in ordinary practice. Supposing one ring only
to be used as in my Boiler of 1882 with a sufficient projection in front for fixing
to frames or cylinders. then the tubes when they began to expand would have the
additional work of moving backwards the whole weight of the boiler, whereas in my
present arrangement the tubes have only to move the front tube plate and its
corrugations forward.
In my arrangement there is the greatest possible freedom given to the tube plate to
move without restraint or undue strain coming on any one part of it.
Furthermore the arrangement within the barrel affords a guide whereby the tube
plate is guided and supported whilst free as above stated to allow for expansion and
contraction of the tubes.
In addition to or in lieu of the corrugated flange of the tube plate one or more of
the circumferential joints of the barrel inay be provided with two corrugated rings
but in this case according to my present invention there is at each joint so provided,
both an inner ring and an outer ring, the inner one being made of copper or other
non-corrosive metal, and having for object not only to add strength to the joint but
also to protect the outer ring from pitting or other injury that might otherwise arise
from contact with water. The convex part or ridge of the inner ring may enter the
annular concavity or channel of the outer ring or the ridge of the inner ring may
project inwardly instead of outwardly.
Referring to Sheets 2, 3 and 4 of the annexed sheets of drawings,
Fig. 1 is a section of a locomotive boiler having a tube plate with a corrugated
flange according to this invention.
Fig. 2 is a section to a larger scale shewing a corrugated circumferential joint ring
for the barrel of a boiler according to this invention.
Fig. 3 shews a boiler having several such joint rings.
Referring to Fig. 1 a is the tube plate; it is formed with a deep flange 6 in which
are two annular corrugations c c. The tube plate and its flange lie completely within
the barrel d to which the flange is rivetted at its edge. e e represent the tubes which
are secured at the ends in any suitable manner. As the tubes expand relatively to
the shell, either owing to their attaining a greater temperature, or being formed of a
metal having a higher co-efficient of expansion, the corrugations c c become flatter,
and allow the tube plate a to take up a new position relatively to the shell.
In Figs. 2 & 3 the corrugations are not formed in the flange of the tube plate, but
are applied to the shell of the boiler as joint rings. Each corrugated joint ring f has
a corrugated cover g of non-corrosive metal interposed between it and the water to
prevent pitting. The number of corrugated joint rings to be employed depends upon
the dimensions of the boiler and the conditions under which it is to be worked.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is
1. In a locomotive or similar boiler a tube plate at the smoke box end of the boiler,
constructed with a flange formed with two or more corrugations as described, enclosed
within the barrel of the boiler and secured thereto as herein before described with
reference to and shewn in Fig. 1 of the drawings, for the purpose mentioned.
2. In a locomotive or similar boiler, constructing the barrel or shell with a joint or
joints formed (or each formed) with an outer corrugated circumferential joint ring
arranged in conjunction with an inner corrugated ring of non-corrosive metal in the
manner and for the purpose specified with reference respectively to Figs. 2 & 3 of the
drawings annexed.
3. In a locomotive or similar boiler providing for expansion and contraction of

page_text: the tubes by constructing the barrel both with a tube plate having a corrugated
flange located within and secured to the barrel and with a joint made with inner and
outer rings in the manner set forth the inner ring being of non-corrosive metal.
Dated this 17th day of May 1889.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.