IMPROVEMENTS IN TUBE FASTENINGS FOR SECTIONAL STEAM BOILERS AND ANALOGOUS DEVICES, AND IN THE METHOD OF SECURING THE TUBES THEREIN."
Year: 1880

page_text: LETTERS PATENT to Edwin Howard Bennett, of Bayonne, in the County of
"
Hudson, in the State of New Jersey, one of the United States of America, for
an Invention of 'IMPROVEMENTS IN TUBE FASTENINGS FOR SECTIONAL
STEAM BOILERS AND ANALOGOUS DEVICES, AND IN THE METHOD OF
SECURING THE TUBES THEREIN."
PROVISIONAL SPECIFICATION left by the said Edwin Howard Bennett at
the Office of the Commissioners of Patents on the 14th December 1880.
EDWIN HOWARD BENNETT, of Bayonne, in the County of Hudson, in the State
of New Jersey, one of the United States of America. "IMPROVEMENTS IN TUBE
FASTENINGS FOR SECTIONAL STEAM BOILERS AND ANALOGOUS DEVICES, AND IN
THE METHOD OF SECURING THE TUBES THEREIN."
My Invention is adapted for securing the tubes of steam boilers and analogous
structures requiring a tight fastening adapted to endure high temperatures and
great strains. It is intended more particularly for application to the style of boilers
known as the "Babcock & Wilcox," having the water enclosed in tubes, and
provided with small end chambers of cast iron suitably connected together to
form a single boiler of a great number of sections.
I have discovered that the holes for the tubes may be produced in the act of
casting in common green sand. I make the holes tapering. The taper facilitates
the drawing of the pattern, and also contributes materially to the perfection of the
fastening.
The strain on this kind of boiler, and in other places similarly conditioned is in
the direction to force the end connection away from the tube. The hole is tapered
so that the outer end is the largest. I employ an expanding tool adapted to give
the same taper to the tube end and force the metal of the tube into the corre-
sponding conical form, applying only sufficient force to slightly imprint the casting
into the outer surface of the expanded tube.
The strain on the connection is always forcing the tapered surfaces into a closer
connection. A tight joint results with little distortion of the metal of the tube.

page_text: My Invention allows tubes to serve successfully which possess a less degree of
ductility than is required for the ordinary modes of setting.
I prefer to employ an expander provided with rollers caged to a ring or equivalent
device, which are forced apart by a tapering mandrel, which may be turned by a
crank or other means, and forced axially as required to present a larger diameter
within the rollers, and thus to force the rollers outward and effect the expansion.
The hole for the reception of the end of the tube in the casting may be finished
with a tool. The rollers of the expander may be tapered in the same direction and
to the same degree as the mandrel, thereby allowing the rollers and the mandrel to
roll together without sliding, and with mathematical precision. The rollers may be
made absolutely cylindrical or tapered in the opposite direction, the mandrel being
correspondingly tapered to induce the required degree of taper in the interior, and
consequently of the exterior, of the tube ends.
I prefer to expand the tubes only to such an extent as to slightly imprint the
casting into the outer tapering surface of the tube end.
The bearing surface is made narrow to facilitate such imprinting.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edwin Howard Bennett in the Great Seal Patent Office on the 14th
May 1881.
EDWIN HOWARD BENNETT, of Bayonne, in the County of Hudson and State of
New Jersey, one of the United States of America. "IMPROVEMENTS IN TUBE
FASTENINGS FOR SECTIONAL STEAM BOILERS AND ANALOGOUS DEVICES, AND
IN THE METHOD OF SECURING THE TUBES THEREIN."
"
My Invention is adapted for securing the tubes of steam boilers and analogous
structures requiring a tight fastening adapted to endure high temperatures and
great strains. It is intended more particularly for the style of boilers set forth in
the several Patents to Babcock and Wilcox, having the water enclosed in tubes
and small end chambers of cast iron suitably connected together to form a single
boiler of a great number of sections.
I have discovered that the holes for the tubes may be produced in the act of
casting in green sand. I make the holes tapering; the taper facilitates the
drawing of the pattern, and also contributes materially to the perfection of the
fastening.
The strain in this kind of boiler, and in other places similarly conditioned, is in
the direction to force the end connection away from the tube. The hole is tapered
so that the outer end is the largest. I employ an expanding tool adapted to give
the same taper to the tube end and force the metal of the tube into the corre-
sponding conical form, applying only sufficient force to slightly imprint the casting
into the outer surface of the expanded tube.
The strain on the connection is always forcing the tapered surfaces into a closer
connection. A tight joint results with little distortion of the metal of the tube.
My Invention allows tubes to serve successfully which possess a less degree of
ductility than is required for the ordinary modes of setting.
But that my Invention may be fully understood I will proceed to describe the
same more in detail by the aid of the accompanying Drawings which form part of
this Specification.

page_text: The rollers may be tapered in the same direction and to the same degree as
the mandrel; in other words, the proper degree of taper for the hole being
determined, it may be divided between the mandrel and the rollers. This allows
the rollers and mandrel to roll together with no sliding, and with mathematical
precision; but I do not esteem this feature essential to success.
The rollers being
made absolutely cylindrical or tapered in the opposite direction, the maundrel
being correspondingly tapered with each to induce the required degree of taper in
the interior, and consequently of the exterior, of the tube ends A¹.
I prefer to expand the tubes only to such an extend as to slightly imprint the
casting B into the outer tapering surface of the end A¹. The bearing surface
is made narrow to facilitate such imprinting.
Having thus described my Invention I would have it understood that I do not
confine myself to the exact details as shown and described, so long as the peculiar
characteristics of my Invention be retained substantially as described, but what
I do claim is,-
First. A steam boiler or analogous construction having castings B, provided
with tapering holes b, in combination with tubes A, having tapered ends A¹,
combined and adapted to serve as and for the purposes herein specified.
Second. The method of setting tubes by expanding the ends conically in
corresponding conical holes in castings B, substantially as and for the purposes
specified.
In witness whereof, I, the said Edwin Howard Bennett, have hereunto set
my hand and seal, this Fourth day of April, A.D. 1881.
Witnesses,
NATHANIEL WATERMAN PRATT.
WILLIAM COLBOURNE BROOKSE.
EDWIN HOWARD BENNETT. (L.S.)