AN IMPROVED STAY BOLT FOR STEAM BOILERS
Year: 1873

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London, for
the Invention of "AN IMPROVED STAY BOLT FOR STEAM BOILERS." -A
communication from abroad by John Cochrane, of the City and
State of New York, United States of America.
Sealed the 9th September 1873, and dated the 19th March 1873.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 19th March 1873.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, do hereby declare the
nature of the said Invention for "AN IMPROVED STAY BOLT FOR STEAM
BOILERS," a communication, to be as follows:—
The screwed stay bolts which are used for securing or fastening the
flat portions or water tables of steam boilers are found to corrode rapidly
from the action of the acids and salts held in solution by the water
within the boilers, while the plate iron of which the boilers are made is

page_text: for the most part but little affected by such chemical action as the plates
are hardened at the surface by the compressing action of the rolls in the
process of manufacturing them. The comparatively inferior ability of
such stay bolts to resist corrosion arises from the fact that the original
surface or outer crust of the bolt is entirely removed by the cutting dies
in forming the screw threads thereon, thus depriving the bolt of its
protecting surface and leaving it pervious to the corroding action of the
acids and salts of the water within the boiler by which it is rapidly
deteriorated.
The object of this Invention is to overcome this defect in the stay bolt
and to make it as durable as the plate iron of the boiler, and this object
I accomplish by artificially hardening its exterior portion or surface.
For this purpose I may enclose the bolts in an iron box with a packing
of animal charcoal and submit them to a red heat in the chamber of a
furnace for about five hours, more or less, and then plunge them into
cold water; or the bolts may be heated to redness in a clean fire and
then rubbed with prussiate or bichromate of potash, which will melt and
flow over the hot surface, when the bolt should be immediately plunged
into cold water; or any other available means of case-hardening may be
adopted. Or the desired result may be accomplished by forming the
screw thread upon the bolt by compression while the bolt is red hot
between a pair of revolving dies having threads thereon corresponding to
the required screw threads upon the stay bolts; the dies must be
inclined or placed to make the threads upon them conform to the rake
or angle of the thread of the required screw. By this means the original
crust or protecting surface of the iron is retained as in the boiler plates.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 19th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM 3
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of March, in the year
of our Lord One thousand eight hundred and seventy-three, in the 3

page_text: thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Robert Lake, Her special
licence that I, the said William Robert Lake, my executors, adminis-
trators, and assigns, or such others as I, the said William Robert Lake,
my executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"AN IMPROVED STAY BOLT FOR STEAM BOILERS," a communication to me
from abroad by John Cochrane, of the City and State of New York,
United States of America, upon the condition (amongst others) that I,
the said William Robert Lake, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement:-
-
The screwed stay bolts which are used for securing or fastening the
flat portions or water tables of steam boilers are found to corrode rapidly
from the action of the acids and salts held in solution by the water
within the boilers, while the plate iron of which the boilers are made is
for the most part but little affected by such chemical action as the plates
are hardened at the surface by the compressing action of the rolls in the
process of manufacturing them. The comparatively inferior ability of
such stay bolts to resist corrosion arises from the fact that the original
surface or outer crust of the bolt is entirely removed by the cutting dics
in forming the screw threads thereon, thus depriving the bolt of its
protecting surfaco and leaving it pervious to the corroding action of the
acids and salts of the water within the boiler by which it is rapidly
deteriorated.
The object of this Invention is to overcome this dafant in star halts

page_text: object I accomplish by artificially hardening their exterior portion or
surface. For this purpose I may enclose the bolts in an iron box with a
packing of animal charcoal, and submit them to a red heat in the
chamber of a furnace for about five hours, more or less, and then plunge
them into cold water; or the bolts may be heated to redness in a clean
fire and then rubbed with prussiate or bicromate of potash, which will
melt and flow over the hot surface, when the bolt should be immediately
plunged into cold water; or any other available means for case-hardening
may be adopted. Or the desired result may be accomplished by forming
the screw thread upon the bolt by compression while the bolt is red hot
between a pair of revolving dies having threads thereon corresponding
to the required screw threads upon the stay bolts; the dies must be
inclined or placed to make the threads upon them conform to the rake
or angle of the thread of the required screw. By this means the original
crust or protecting surface of the iron is retained as in the boiler plates.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and the manner of performing the
same, I wish it understood that I claim, a screwed stay bolt for steam
boilers having its surface artificially hardened or formed by compression,
as herein described.
"
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Nineteenth day of September,
in the year of our Lord One thousand cight hundred and seventy-
three
Witness,
JAMES EDWARDS,
8, Southampton Buildings,
London.
WN. ROBT. LAKE. (L.S.)