Improvements applicable to the Fire Boxes and Tubes of Steam Boilers of the Locomotive Type.
Year: 1893

page_text: Date of Application, 10th Apr., 1893-Accepted, 13th May, 1893
COMPLETE SPECIFICATION.
Improvements applicable to the Fire Boxes and Tubes of Steam
Boilers of the Locomotive Type.
I WILLIAM MALAM of 911 Ashton Old Road Fairfield near Manchester, in the
County of Lancaster, Boiler Maker, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement :-
This invention relates to the construction of the fire boxes of steam boilers of
the locomotive type and also of the fire tubes, and the method of fixing the same
in the front sheet of the fire box and in the tube plate, the principal objects of the
invention being first to make a corrugated fire box and so obtain increased heating
surface without diminishing the area of the fire bars, and secondly to allow of the
expansion and contraction of the fire tubes without danger of loosening their.ends.
The nature of my said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference
to the sheet of drawings hereunto annexed and the following explanation thereof.
Fig. 1 is a longitudinal section through a boiler and firebox of the locomotive
type shewing the application of my invention thereto.
Fig. 2 is a half- transverse section and elevation of the same, Fig. 3 a half
horizontal section and plan view and Fig. 4 a modification of the same.
a represents the shell or outer casing of the boiler.
In the crown sheet 6 of the fire box the corrugations run in a transverse direction
and terminate flush in the same vertical plane with the side sheets c of the firebox.
The sides of the crown sheet are preferably provided with vertical flanges b¹ by
means of which they are rivetted to the side sheets (see Fig. 2) so that separation
of the crown sheet from the side sheets would necessitate the shearing of these
rivets. The hottom sheet d of the fire-box is also preferably attached to the side
sheets c in a similar manner.
The vertical corrugations in the side sheets c are not made of the same depth
from the top to the bottom but are wedge shaped as seen at Fig. 2 being of the
full depth where they commence at or near the top, and gradually becoming
shallower until they disappear at or above the lowest line of rivets where the
bottom sheet is connected so that there is little or no diminution of the area of
the fire bars. The water space is also carried under the fire box as shown at e
Figs. 1 and 2 whereby I obtain the advantages of what is known as a wet
bottom" in combination with a corrugated fire-box.
"
I make the fire tubes with circumferential corrugations at each end whereby
they can expand and contract longitudinally without danger of loosening their
connections with the front sheet c¹ of the fire box or with the tube plate g. The
holes in the plates after being drilled have their edges made concave or convex so
that the corrugations on the ends of the tubes may be expanded to fit thereinto so
as to make a strong and perfectly safe joint. The plates e and 9 are also made
thicker or stronger at the holes preferably by the same tool which shapes the
concave or convex sides thereof (see Fig. 1).
In the modification shown at Fig. 4 the outside shell a of the boiler is shown
as slightly corrugated in a vertical direction opposite to each wedge shaped
corrugation in the side sheets c of the firebox, whereby I am enabled to dispense
with the long stays shown on Fig. 3.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
First In the corrucated fire have of a locomotive tone of boiler making the

page_text: vertical corrugations in the side sheets wedge shaped that is to say of the full
depth at or near the top and gradually diminishing towards the line of grate bars
so as to obtain the increased heating surface without diminishing the area of the
firebars, substantially as hereinbefore described and illustrated by the drawings
annexed.
Secondly I claim in a corrugated fire box the combination with the side sheets
(corrugated as described in the preceding claim) of a corrugated crown sheet
connected by a vertical joint so that they cannot be separated without shearing the
rivets substantially as hereinbefore described and illustrated by the drawings
annexed.
:
Thirdly I claim the combination with a corrugated fire box of a water space
extending beneath the bottom of the said fire box substantially as hereinbefore
described and illustrated by the drawings annexed.
Fourthly I claim the method of corrugating the ends of the fire tubes and
connecting them with the front sheet of the fire box and with the tube plate
substantially as hereinbefore described and illustrated by the drawings annexed.
Fifthly I claim the tube plates c' and 9 made stronger at the holes where the
tubes are inserted substantially as hereinbefore described and illustrated by the
drawings annexed.
Dated this 8th day of April 1893.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.