of Steam Boilers and similar Structures.
Year: 1885

page_text: of Steam Boilers and similar Structures.
I, ROBERT ANTHONY HARDCASTLE, of 30 Hyde Terrace, Leeds, in the County
of York, Engineer, do hereby declare the nature of said invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF FIREBOXES AND OTHER PARTS OF STEAM BOILERS
AND SIMILAR STRUCTURES" to be as follows:→
This invention has reference to the construction of fireboxes and other parts of
steam boilers and similar structures.
A fire box of the locomotive type as at present constructed is surrounded (except
at the bottom) by a water space between it and the outer shell of the boiler and
has its flat sides fortified against the collapsing strain pressing upon them, by a
number of stays screwed into it and into the outer shell and which are afterwards
rivetted over at both ends, and when such firebox is constructed of metallic plates
thinner than those constituting the said outer shell, the number of screw threads in
the metallic plate forming such fire-box is obviously less than those in the plate of
the outer shell. And in order that such number of threads shall be equal or nearly
so in both, that the stays may have about equal hold therein, I form at the parts of.
the fire box for receiving the stays, an extra thickness of metal by embossing or
raising projections thereon, (such embossings I prefer shall be on that side of the
metallic plate next to the water space) thus preventing the liability of one end of
the stays being stripped before the other by the pressure brought to bear upon.
them. The embossments at the same time impart additional strength against the
collapsing strain, than as heretofore constructed.
In tube plates when the distance of the tubes is sufficiently far apart to admit.
of them I form similar embossinents to those just described on the fire boxes, and
also on other parts of boilers and similar structures, for the reception of and for
giving a greater bearing surface to the tubes or stays, for making a better joint and
preventing leakage at such parts which at all times forms a source of danger. The
said embossments or projections I form out of the ordinary thickness of the metallic
olate by punches and dies (which may be in rolls or otherwise) having suitable
configuration for producing the same, and at the same time either form the holes
eady for being threaded for the reception of the stays or otherwise.
In forming the embossments and holes for the reception of tubes the holes should
e afterwards bored out to fit them.
Dated this 1st dom ST. 200

page_text: of Steam Boilers and similar Structures.
I, ROBERT ANTHONY HARDCASTLE of 30 Hyde Terrace, Leeds, in the County
of York, Engineer, do hereby declare the nature of said invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF FIRE-BOXES AND OTHER PARTS OF STEAM BOILERS
AND SIMILAR STRUCTURES," 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 the construction of fire-boxes and other parts of
steam boilers and similar structures. A fire box of the locomotive type as at
present constructed is surrounded (except at the bottom). by a water space between
it and the outer shell of the boiler and has its flat sides fortified against the
collapsing strain pressing upon them by a number of stays screwed into them and
into the outer shell and which are afterwards rivetted over at both ends, and when
such a fire-box is constructed of metallic plates thinner than those constituting the
said outer shell, the number of screw threads in the metallic plate forming the
fire-box is obviously less than in the plate of the outer shell. Now in order that
such number of threads shall be equal or nearly so in both, and that the stays may
have about equal hold therein, I form at the parts of the fire-box for receiving
the stays, an extra thickness of metal by embossing or raising projections thereon,
(such embossments I prefer shall be on that side of the metallic plate next to the
water space) thus preventing the liability to stripping of one end of the stays
before the other by the action of the pressure brought to bear upon them. The
embossments at the same time impart greater strength to resist the collapsing strain
than is afforded with the ordinary construction. In tube plates when the tubes
are sufficiently far apart to admit of them, I form similar embossments to those
just described with respect to fire-boxes and provide like embossments also on other
parts of boilers and similar structures to receive and give a greater bearing surface
to the tubes, in order to produce a better joint and prevent at such parts leakage
which at all times constitutes a source of danger. The said embossments or
projections I form out of the ordinary thickness of the metallic plate by punches
and dies (which may be in rolls or otherwise) having suitable configuration for
producing the desired forms. The holes to be threaded for the reception of the
stays, may either be formed at the same time as the embossments or otherwise.
After forming the embossments and holes for the reception of tubes, the holes
should be bored out to fit them,
In the accompanying drawings Fig. 1. represents a vertical section of a portion
of a fire box and boiler shell of the locomotive type with embossments b, on the
plate a, of the fire box these embossments being such that where they occur the
total thickness of the fire box plate is equal or thereabout to that of the plate c, of
the outer shell of the boiler so that as the stays d, are screwed into both, it follows
that they have the same number of screw threads or equal hold in each.-Fig. 2
shews the tube plate of a marine or other boiler with an embossment 61, on the
⚫ tube plate a 1, around the opening to receive a tube e, thus giving a longer bearing
surface for the tube than the plate would otherwise afford.

page_text: Having 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
The construction of fire-boxes and other parts of steam boilers and similar
structures with plates formed with embossments at those parts into which stays or
tubes are inserted, substantially in the manner and for the purpose hereinabove
described and set forth with reference to the drawings hereunto annexed.
Dated the 17th T-1 100
R. A. HARDCASTLE,