AN IMPROVED PROCESS FOR TEMPERING AND FORMING ARTICLES OF STEEL OR STEEL AND IRON, AND APPARATUS CONNECTED THEREWITH
Year: 1874

page_text: LETTERS PATENT to Peter Jensen, of 89, Chancery Lane, in the
County of Middlesex, for the Invention of "AN IMPROVED PROCESS
FOR TEMPERING AND FORMING ARTICLES OF STEEL OR STEEL AND IRON, AND
APPARATUS CONNECTED THEREWITH." -A communication from abroad by
George Frederick Simonds and James Augustus Ferson, both of
Fitchburg, in the State of Massachusetts, in the United States of
America, Machinists.
Sealed the 5th March 1875, and dated the 16th December 1874.
PROVISIONAL SPECIFICATION left by the said Peter Jensen at the
Office of the Commissioners of Patents, with his Petition, on the
16th December 1874.
I, PETER JENSEN, of 89, Chancery Lane, in the County of Middlesex,
do hereby declare the nature of the said Invention for "AN IMPROVED
PROCESS FOR TEMPERING AND FORMING ARTICLES OF STEEL OR STEEL AND IRON, AND
APPARATUS CONNECTED THEREWITH," (a communication to me from abroad by
George Frederick Simonds and James Augustus Ferson, both of Fitch-

page_text: Machinists,) to be as follows:-
This Invention relates to the hardening, tempering, and bringing to
their ultimate form articles of steel, or of steel combined with iron, and
it consists,-
First. In the process as herein-after described.
Second. In the construction and arrangement of the tempering oven
necessary to carry out the process and ensure success.
In this process the articles to be treated are heated in the usual
manner, and after hardening are again heated for tempering and forming.
When at a proper heat the metal is compressed in a clamp constructed
for the purpose, in which the opposite compressing surfaces are either
straight or shaped to suit the form required in the article to be produced.
Up to this point this process is common and well known, the same
having been practised in efforts heretofore made to temper and straighten
saws after hardening. It is well known in mechanical and manufacturing
circles that all such efforts have heretofore proven unsuccessful, or only
partially successful, and saws when taken from the clamps have required
hammering to a greater or less extent, thus adding materially to the cost
of the article produced.
The object of this Invention is to overcome the difficulty heretofore
experienced, and to accomplish this it has been ascertained by a long
course of experiments in what the difficulty lies, and herein consists
essentially this Invention.
During the
process of tempering it was found necessary to make avail
of the greatest ultimate heat allowable in producing a spring temper,
and having reached this point the heat and compression are maintained
a sufficient time, say, about thirty minutes, more or less, to allow the
particles of metal to assume a proper relation to each other, and the
article to take permanently the form of the clamping surfaces. Another
condition of success is a perfect evenness of heat from the time this new
part of the process begins until it ends. The proper degree of heat as
well as its required regularity may be easily determined in a dark room,
where the clamps will show the same regular dark red color throughout,
any irregularity of heat readily showing itself; or it may be determined
by simply sprinkling sawdust over the entire clamp, when if the sawdust

page_text: burns with a quick bright sparkle over the entire surface it shews that
the proper temperature is attained, and the article after a proper lapse of
time may be safely removed from the clamps without fear of its twisting
or warping.
The second part of this Invention relates to the construction of the
oven necessary to secure the perfect evenness of temperature requisite to
secure success in the above process. In tempering ovens heretofore
made the clamps or dies have been placed in direct contact with the
flame from the fire, where it is found impossible to produce that evenness
of heat necessary. The great purpose of this part of the Invention is to
avoid any contact of the clamps with the fire, and only allow them to
receive the heat after it has been evenly dispersed, thereby securing a
uniformity of heat throughout the clamps and the article to be treated.
:
In the front wall of an oven is a suitable door for the introduction of
the articles to be tempered and formed. In the top are openings
usually four in number, to allow the heat to pass off, and to produce a
draft when the smoke flue is closed. In the bottom are openings to
allow the heat to distribute itself evenly through the oven, and surround
the clamps which compress the article to be tempered and formed.
Immediately over the fire-box is placed a heavy fireproof tile extending
slightly over the sides of the fire-place, so as to catch and arrest tho.
direct heat from the flame. Air passages are left on cach side of the tile.
Above the tile, and between that and the arch of the fire-box is formed a
hot-air chamber into which the air passages lead. Above the hot-air
chamber, and leading through the masonry to the tempering oven, arc
radiating flues which again distribute and equalize the heat before it
reaches the perforated bottom of the oven. This bottom in turn becomes
heated throughout its extent, and materially aids in producing that
evenness of temperature within the oven which is absolutely necessary to
secure success.
The perforations in the bottom may be closed when it is desired to
shut off the gas from the article being treated, for instance, when it is
desired to determine the condition of the article being treated by its
colour.
When the article to be treated has been properly hardened it is placed
between the clamps, and there secured by any convenient means, the
clamps having been first heated so as to impart to the article a sufficient:

page_text: heat to allow bringing them together without cracking the article. For
this purpose it is preferred to use wedges driven into the slotted rod.
The clamps may rest within the oven and be operated by a rod or
otherwise. In the latter case the article to be treated is properly com-
pressed between the clamps, and the clamps then secured, after which 5
they are passed into the oven, the form of the clamps, as shown, allowing
a free contact with the heat.
"
To straighten articles that are out of the required form, and that do
not require to be rehardened, like circular saws for instance, which have
been warped or blistered in use, they are placed between the clamps 1
and treated as before described. The process is also applicable to articles
which are left sufficiently hard from rolls or hammers.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Peter Jensen in the Great Seal Patent Office on the
16th June 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
JENSEN, of 89, Chancery Lane, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of December, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Peter Jensen, Her special licence, that I,
the said Peter Jensen, my executors, administrators, and assigns, or
such others as I, the said Peter Jensen, 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 PROCESS FOR TEMPERING AND
FORMING ARTICLES OF STEEL OR STEEL AND IRON, AND APPARATUS CONNECTED
THEREWITH," (a communication to me from abroad by George Frederick
Simonds and James Augustus Ferson, both of Fitchburg, in the State of

page_text: During the process of tempering they found it was necessary to avail
themselves of the greatest ultimate heat allowable in producing a spring
temper, and having reached this point they maintain the heat and com-
pression a sufficient time, say, about thirty minutes, more or less, to
allow the particles of metal to assume a proper relation to each other,
and the article to take permanently the form of the clamping surfaces.
Another condition of success is a perfect evenness of heat from the time
the new part of this process begins until it ends. The proper degree of
heat as well as its required regularity may be easily determined in a
dark room, where the clamps will show the same regular dark red colour
throughout, any irregularity of heat readily showing itself; or it may be
determined by simply sprinkling sawdust over the entire clamp, when if
the sawdust burns with a quick bright sparkle over the entire surface it
shows that the proper temperature is attained, and the article after a
proper lapse of time may be safely removed from the clamps without fear
of its twisting or warping.
The second part of this Invention relates to the construction of the
oven necessary to secure the perfect evenness of temperature requisite to
secure success in the above process. In tempering ovens heretofore
made the clamps or dies have been placed in direct contact with the
flame from the fire, where it is found impossible to produce that evenness
of heat necessary. The great purpose of this part of this Invention is to
avoid any contact of the aforesaid clamps with the fire, and only allow
them to receive the heat after it has been evenly dispersed, thereby
securing a uniformity of heat throughout the clamps and the article to
treated.
-
But that this Invention may be fully understood, I will now procced
to describe the same in detail by reference to the accompanying
Drawings which form part of this Specification, and in which Figure 1
represents a vertical cross section of this improved tempering oven;
Figure 2 is a vertical longitudinal section of the same; Figure 3 shows
the clamps for holding the article to be tempered and formed.
A, A, represent the walls of an oven chamber; B, the roof or top;
and O, the bottom. In the front wall is a suitable door a for the
introduction of the articles to be tempered and formed. In the top are
openings 6, usually four in number, to allow the heat to pass off, and to
produce a draft when the smoke flue b¹ is closed. In the bottom are

page_text: openings c, c, to allow the heat to distribute itself evenly through the
oven and surround the clamps D, D', which compress the article to be
tempered and formed. Immediately over the fire-box is placed the
heavy fireproof tile E, extending slightly over the sides of the fire-place,
so as to catch and arrest the direct heat from the flame. Air passages e, e,
are left on each side of the tile. Above the tile, and between that and
the arch of the fire-box is formed the hot-air chamber F into which the
air passages e, e, lead. Above the hot-air chamber, and leading through
the masonry to the tempering oven, are the radiating flues f, which
again distribute and equalize the heat before it reaches the perforated
bottom of the oven. This bottom in turn becomes heated throughout
its extent, and materially aids in producing that evenness of temperature
within the oven which is absolutely necessary to secure success.
The perforations in the bottom may be closed when it is desired to
shut off the gas from the article being treated; for instance, when it is
desired to determine the condition of the article being treated by its
colour.
When the article to be treated has been properly hardened it is placed
between the clamps D, D', and there secured by any convenient means,
the clamps having been first heated so as to impart to the article. a
sufficient heat to allow bringing them together without cracking the
article. It is preferred to use wedges driven into the slotted rod, as
shown in Figure 3.
The clamps may rest within the oven and be operated by the rod d¹;
or they may be constructed as shown in Figure 3. In the latter case
the article to be treated is properly compressed between the clamps, and
the clamps then secured, after which they are passed into the oven,
the form of the clamps, as shown, allowing a free contact with the
heat.
To straighten articles that are out of the required form, and that do
not require to be rehardened, like circular saws, for instance, which have
been warped or blistered in use, they are put between the clamps and
treated as before described. The process is also applicable to articles
which are left sufficiently hard from rolls or hammers.
Having thus described the nature of this Invention, and the mode in
which the same is carried out, I would have it understood that the
Invention is not restricted to the exact details herein laid down as to the

page_text: form and construction of this oven, as the same may be changed in
various ways without departing from the essential principles involved;
but what I claim as new and desire to secure by Letters Patent is,—
First. The process herein described for tempering and bringing
hardened articles of steel, or steel combined with iron, to any required
form by clamping them between plates or forms, and heating to that
uniform temperature which is consistent with the required temper, and
keeping them at that heat for the length of time required for the articles
to take permanently the form of the clamping surfaces, substantially as
and for the purposes set forth.
Second. In a tempering or tempering and forming oven an intervening
plate or perforated plate between the fire and the clamps or dies, for the
purpose of securing an evenness of heat in the clamps, substantially as
and for the purposes set forth.
Third. A tempering or a tempering and forming oven constructed
with a perforated bottom for the admission and even distribution of heat
around the article to be treated, substantially as and for the purpose set
forth.
Fourth. A tempering or a tempering and forming oven, constructed as
described, in combination with the passages e, e, hot-air chamber F, and
tile E when arranged to operate, substantially as and for the purpose set.
forth.
In witness whereof, I, the said Peter Jensen, have hereunto set my
hand and seal, this Sixteenth day of June, in the year of our Lord
One thousand eight hundred and seventy-five.