Improved Process and Apparatus for Hardening Metals.
Year: 1898

page_text: Date of Application, 2nd Sept., 1898-Accepted, 12th Nov., 1898
COMPLETE SPECIFICATION.
Improved Process and Apparatus for Hardening Metals.
We, CHARLES WILLIAM SPONSEL, of 22, Huntington Street, and WILLIAM ALBERT
LORENZ, of 96, Garden Street, both in the City of Hartford and State of Connecti-
cut, United States of America, Mechanical Engineers, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement: —
This invention relates to an improved process of hardening metals, and to an
improved apparatus for carrying out that process, the object sought in the inven-
tion of the process being to forcibly apply cooling liquid against the hot metal,
and to withdraw therefrom the liquid which is heated by the contact, so as to
conduct away the heat of the metal as rapidly and uniformly as possible. The
object sought in the invention of the means for carrying out the improved process
is to provide a compact, convenient and effective apparatus that will properly
direct and circulate the liquid in accordance with the requirements of that process.
In order that the relation of this invention to the prior art may be more readily
apprehended, brief mention will be made of the methods already known.
First, by projecting the cooling liquid in jets against the unsubmerged surface
of the metal, the liquid flowing over the surface away from the respective points
or surfaces of impact. Second, by flowing the cooling liquid continuously along
the surface of the metal. Third, by projecting two oppositely disposed currents,
either submerged or unsubmerged, against the opposite sides of the piece to be
hardened, cach current, upon striking the metal, flowing in all directions away
from the point or surface of impact.
In other forms of hardening apparatus in use, the cooling liquid is agitated by
paddles, or jets are used to cause a general circulation of the cooling liquid in
the tank, without reference to any intelligible system. In other cases, the liquid
is forced through a nozzle in the bottom of a barrel, thereby establishing a current,
and into this current the heated article is dipped. The still commoner practice
is to dip the heated article into a tank of quiescent liquid, and move it rapidly
about therein.
It is well known that the contact of liquid with a heated metallic surface causes
the instant formation of a layer of steam, which in a great degree insulates or
protects the surface of the metal from the cooling action of the liquid, and it is
necessary to wash or force away this layer of steam as rapidly as it forms, and
uniformly over the surface of the metal, in order to allow the cooling action of the
liquid to have prompt, continuous, and uniform access thereto. While in some
of the above mentioned known processes, some of the steam may be partly removed
by the action of the liquid wherever its pressure may be the greatest, it is found
that all of them are liable to leave some portions of the surface protected by the
steam, with the result that the surfaces thus protected will be softer than those
which are continuously in contact with the cool liquid during the chilling opera-
tion. These soft spots might not materially lessen the utility of objects like
armor plates, for example, but their existence in tools like dies, reamers, taps,

page_text: cutters, or in some kinds of rolls, would seriously lessen both the degree and the
term of efficiency of such articles.
The present improved process consists in forcing the cooling liquid under pres-
sure in a series of submerged sheet-currents against the heated surface of the
metal to be hardened, and in directing the flow of the mingled steam and heated
liquid laterally away from the surface of the metal between the inwardly forced
cold currents.
The preferred means or apparatus for carrying out this improved process com-
prises a tank and a series of current-emitting pipes or chambers suspended therein,
having inwardly-facing primary current-emission outlets through which the
liquid is forced against the metal, and having also secondary current-emission
outlets through which the liquid is forced in a direction to induce a flow of the
heated liquid outwardly between the primary or inward currents. The primary
current chambers are preferably set so as to direct the flow of the liquid at an angle
against the heated metal, having small intervals between them for the lateral
escape of the heated liquid, the outward flow of which is aided or induced by the
influence of the secondary currents.
Figure 1 of the drawings is a plan view of the apparatus. Fig. 2 is a front
view of the same, in section taken on the line 2-2 of Fig. 1. Fig. 3 is an enlarged
plan view in section taken on the line 3-3 of Fig. 4. Fig. 4 is an enlarged
front view in section taken on the line 4-4 of Fig. 3. Fig. 5 is a plan view, in
still further enlarged scale, in section taken on the line 5-5 of Fig. 4. Fig. 6 is
a plan view of a modified arrangement of the apparatus.
The preferred means of carrying out this process is the apparatus shown in the
drawings, which is suspended by means of its distributing-head 9 upon the cross
braces 10 and 11, attached to the tank 12. The head 9 is formed with a central
opening 13, around which extends a somewhat irregular annular chamber 14,
having a dividing piece 15 for directing the inflowing liquid in opposite directions
for distribution around the annular chamber. The current-emitting pipes or
chambers 16 are each provided with a primary current outlet 18, and with
secondary current outlets 19. The pipes are screwed into the head at 17, and their
lower ends are closed by means of the screw caps 20. Resting upon these caps,
and encircling the series of current chambers 16, is the annular deflecting plate 22,
which is provided with a central aperture 23 for receiving the fixture or other
device for supporting and centering the articles to be hardened. In Figs. 3 and 4
the apparatus is shown to be fitted with a supporting plate 24, having a conical
recess for centering and supporting a mandrel 26, the upper end of which is
centered with the apparatus by means of the flange 27. In this illustration of the
use of the apparatus, the articles to be hardened are shown as a series of rings 28,
which are cut into segments and are clamped together upon the mandrel by means
of collars and a key.
The current-emitting pipes or chambers 16 may be turned in their bearings
in the distributing head 9 so as to alter to any desired extent the angle of the
emitted currents, the threads being fitted tightly enough to hold the pipe in the
position to which it may be adjusted; or the latter may be secured in their posi-
tions by check nuts or set screws in any of several well known ways. The
intervals between these pipes are made wide enough for the proper exit of the
liquid between them. Inasmuch as the space encompassed by the series of pipes
is practically closed at its lower end by the deflector plate 22, and at its upper end
by the head 9, and the flange 27, the liquid injected into that space through the
primary current outlets 18 cannot escape endwise, but finds its only outlet at the
intervals between the pipes 16, between which it therefore flows freely, thus
rapidly carrying the heated liquid laterally away from the metal. This disposition
of the primary currents enables them to cut or scour the steam away from the
surface of the article to be hardened, thus preventing the formation of steam
pockets, and thereby rapidly and uniformly cooling the article.
The preferred means for conveying and forcing the cooling liquid to the

page_text: apparatus, as shown in the drawings consists of a force pump 30, provided with
a pulley 31, which is driven by means of a belt from any convenient shaft. The
inlet or suction chamber of this pump is connected with the bottom of the tank
by means of the pipe 32, while the outlet or discharge chamber of the pump is
connected with the inlet opening 33 of the distributing-head 9 of the apparatus by
means of the pipes 34 and 35. These pipes may, if desired, be also connected
by means of the pipe 36 with a reservoir, or series of reservoirs, (not herein shown)
for storing one or more special kinds of cooling liquid, in which case, by closing
the valve 37, between the pump and the apparatus, and opening the valve or
valves 38, connecting with the desired reservoir, any of these special liquids may,
after use, be pumped from the tank into its appropriate reservoir and there pre-
served until it is again required, when, by opening its valve 38, and the valve 37,
it is allowed to flow into the tank.
An overflow pipe 40 is preferably connected with the upper part of the tank,
so as to maintain the desired level of the liquid, as indicated by the dot and dash
line 41. An emptying pipe 42, provided with a valve 43, may also be employed
for emptying the tank, and this pipe, as shown in Figs. 1 and 2, may be connected
with the overflow pipe 40.
The process of forcing and directing the series of submerged sheet-currents of
the cooling liquid against the metal, and of directing the subsequent flow of the
heated liquid laterally away from the metal between the forced sheet-currents, is
performed by this apparatus as follows, it being presumed that the tank is empty:
The valve 43 is closed, and the valves 37 and 38 are opened, thereby admitting
the liquid to the tank 12, filling it preferably to about the level of the line 41, or a
little higher than the tops of the primary current outlets 18. In employing a
pump or equivalent means for repeatedly circulating the liquid, the valve 38
should be closed. Upon starting the pump, the liquid is withdrawn, from the
bottom of the tank through the pipe 32, and is forced through the pipes 34 and 35
into the distributing-head 9, thence into the series of pipes or current chambers 16,
and through the emission outlets 18 and 19, as indicated by the arrows in the
figures. The article to be hardened, after being raised to the proper degree of
heat, is transferred immediately from the furnace to the apparatus, through the
opening 13, where, if of suitable form, it may be supported in the centering
cone 24.
The liquid of the primary currents 45, deflected and heated by its contact with
the surface of the metal, flows laterally through the intervals between the pipes 16,
since the deflecting plate 22, the head 9, and the flange 27 prevent its downward
or upward escape, and by further reason of the operation of the secondary
currents 48, which also aid or induce this desired outward flow of the heated
liquid.
The primary current outlets 18, in the pipes 16, should be made in length sub-
stantially equal to that of the longest article to be hardened, and of a width
adapted to emit a volume of liquid suited to the size of those articles. The
secondary outlets 19 are preferably made narrow, so that the combined area of
the two outlets 19 is less than the area of the outlet 18. These outlets may be
continuous, as 18, or interrupted, as 19. The outlets 18 should not, however, be
interrupted sufficiently to prevent the delivery of a substantially unbroken sheet-
current against the metal to be hardened.
The general directions of flow of the various currents are best represented in
Fig. 5, by means of arrows. The current outlets 18 are preferably placed so as
to direct the sheet-currents at an angle against the metal, as shown by the line 45,
which represents the primary current. Upon striking the metal the current is
deflected as at 46. Part of this current will necessarily intermingle with the next
current 45, but the larger portion of the heated liquid when deflected from the
metal, flows off in the direction shown at 47, between the two currents 45. This
outward flow is aided by the two secondary currents 48, 48, which combine and
form an outward flowing resultant current 49, thus thoroughly intermingling the

page_text: liquid in the tank 12 at the outer part thereof, whence it flows downward, and is
drawn through the suction pipe 32 to the pump, and is thus circulated repeatedly
through the apparatus.
The forced sheet-currents 45 should be substantially submerged to give the best
results, because their tendency then is to retain their respective levels and flow
away laterally. If the currents 45 were not submerged, they would, upon striking
the article, flow downwardly to the deflecting plate, and the lower part of the
article would receive the hot liquid, thus varying the cooling effect. Substantially
the same effect may be produced by making the primary currents large enough in
volume to fill the exit intervals between the pipes 16 with the outflowing currents,
thus keeping the primary currents 45 substantially submerged without employing
a tank for that purpose, and still keeping within the intent and scope of the
present invention.
Any available means for forcing the liquid through the apparatus may be
employed in place of the pump 30. When the apparatus is used in a locality
having a supply of water under a suitable head, the apparatus may be connected
with that supply, allowing it to run to waste through the overflow pipe 40, thereby
dispensing with the pump.
Where the articles to be hardened are cylindrical or symmetrical in form, it will
be found convenient to arrange them side by side upon a mandrel or equivalent
device, as herein shown. For articles having special or peculiar shapes, special
fixtures may be provided, adapted to rest in the supporting plate 24 or in its
aperture 23, the upper end of the fixture being guided or centered by the open-
ing 13 in the head 9.
In the modification shown in Fig. 6, the article to be hardened is shown as a
rectangular piece 51, and the current emitting pipes 52 are arranged in corre-
sponding rectangular form encompassing the piece, and emit the primary
currents 55 thereagainst, while the secondary currents 54 induce an outward flow,
all mingling in the resultant current 55.
By the use of this process, a lower degree of heat or a lower grade of steel, or
both, may be made to serve purposes ordinarily requiring the employment of the
better grades of steel, and a comparatively high degree of heat, if hardened by the
ordinary methods.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. The process of cooling metallic bodies, which consists in directing a series
of forced sheet-currents of cooling liquid against the metal, and in directing the
subsequent flow of the heated liquid laterally away from the metal between the
forced sheet-currents.
2. The process of cooling metallic bodies, which consists in forcing a series of
sheet-currents laterally against the heated metal, and in inducing the subsequent
outward flow of the heated liquid laterally away from the metal at the intervals
between the inwardly forced currents.
3. The process of cooling heated metallic bodies, which consists in forcing a
series of submerged sheet-currents laterally against the heated metal, and in
forcing another series of submerged sheet-currents laterally away from the metal
at the intervals between the inwardly forced currents so as to induce the lateral
outward flow of the heated liquid.
4. The process of cooling metallic bodies, which consists in forcing a series of
submerged sheet-currents of cooling liquid against the metallic body at an angle
to the surface thereof.
5. The process of cooling metallic bodies, which consists in the forcing of a
series of submerged sheet-currents of cooling liquid against the metal at an angle
to the surface thereof, and in directing the heated liquid laterally outward from
the intervals between the impinging sheet-currents.
0

page_text: 6. In a hardening apparatus, in combination with means for forcing a supply
of liquid, a current-emitting chamber connected therewith and provided with a
longitudinal current-emitting outlet, the chamber being made adjustable upon
its axis so as to alter the angular direction of emission of the forced current.
7. In a hardening apparatus, in combination with means for forcing a supply
of liquid, a distributing head connected with the liquid forcing means, a series
of current-emitting chambers connected with the head, and provided with longi-
tudinal current-emitting outlets.
8. In a hardening apparatus, in combination with means for forcing a supply
of liquid, a distributing-head connected with the liquid-forcing means, a series
of current-emitting chambers connected with the head, provided with longitudinal
current-emitting outlets, and having intervals between the chambers for the exit
of the liquid, with means for closing the ends of the space encompassed by the
chambers, so as to deflect the discharging liquid to the intervals between the
chambers.
9. In combination with a tank and with means for forcing a supply of liquid, a
hardening apparatus located within the tank, comprising a distributing-head,
and a series of current-emitting chambers connected therewith provided with
longitudinal current-emitting outlets.
10. In a hardening apparatus, a series of current-emitting chambers, arranged
to encompass a space for receiving the articles to be hardened, and having inter-
vals between them for the discharge of the cooling liquid, with deflecting means
for closing the ends of the space encompassed by the chambers, whereby the liquid
is discharged only at the intervals between the chambers.
11. In a hardening apparatus, a series of current-emitting chambers, arranged
to encompass a space for receiving the articles to be hardened, and having intervals
between them for the discharge of the cooling liquid, with means for centering
the articles to be hardened with the current-emitting chambers.
12. In a hardening apparatus, a series of current-emitting chambers, arranged
to encompass a space for receiving the articles to be hardened, and having inter-
vals between them for the discharge of the cooling liquid, a deflector plate for
closing the lower end of the space encompassed by the chambers, and provided
with a conical recess for centering the articles to be hardened with the current-
emitting chambers.
1
1 1
1000
DAY, DAVIES & HUNT,
Chartered Patent Agents, 321, High Holborn, London, W.C.,
Agents for the Applicants.