IMPROVEMENTS IN METHOD AND APPARATUS FOR VULCANIZING RUBBER
Year: 1885

page_text: Now Know Ye that J, FREDERICK WHEATON. SEABURY, of 25 Union Street,
Providence, in the County of Providence, State of Rhode Island, United States of
America, Dentist, do hereby declare the nature of my invention for IMPROVEMENTS
IN METHOD AND APPARATUS FOR VULCANIZING RUBBER, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:-
Heretofore rubber goods have been vulcanized in ovens by heating the same
with steam and also by heating the ovens by fire. Rubber goods have also been
vulcanized by being placed in proper receptacles constructed to withstand internal
pressure and filling these receptacles with steam under pressure.
The first method was defective in that the air contained in or between the rubber
expanded so readily as to cause blisters and the warping of the rubber. In the
second method the steam condensed on the goods and caused pock marks by which
the appearance of the goods was injured.
The thorough vulcanization of rubber requires the gradual raising of the
temperature so that the sulphur contained in the rubber will flow through the
whole mass and combine equally with all the atoms of the rubber whilst the rubber
is under pressure.
By virtue of my invention all of the above defects are avoided, for while the
rubber is subjected to the direct action of steam the steam is maintained in
a perfectly superheated condition throughout the entire period of its action upon
the rubber, so that all possibility of condensation is avoided, while the utmost
uniformity in the product is attained.
My invention consists in a peculiar and novel-method of vulcanizing rubber, and
in the peculiar and novel apparatus for carrying the said method into effect.
I will first proceed to describe the method of vulcanizing. The rubber in mass
or in moulds is placed in a chamber or receptacle which is enclosed in an outer
casing or shell so as to leave a space between the chamber and shell. The shell
contains a combustion chamber the heat generated in which acts upon the chamber
externally but does not enter within it.
The interior of the chamber is placed in communication with a suitable steam-
boiler in which superheated steam is generated.

page_text: It will-therefore be seen that when the steam is thrown into the chamber no
condensation whatever can occur, because the heat from the combustion-chamber
acting upon the vulcanizing chamber heats the latter to such a degree as to maintain
the steam within the vulcanizing-chamber in a superheated condition. Hence the
method consists in subjecting the rubber to the direct heat and pressure of the
steam and maintaining the steain in a superheated condition by means of an
auxiliary furnace acting directly upon the vulcanizing chamber. The result of this
method is that perfect uniformity in the product is attained by the vulcanizing
process. The advantage of direct contact of the steam in preventing warping and
thoroughly permeating the mass of rubber are obtained while all liability to
blistering, burning, or pock marking is avoided.
I will now proceed to describe the apparatus for carrying the above method into
effect; referring to the accompanying drawings, in which
Figure 1 is a longitudinal section of my improved vulcanizer.
Figure 2 is a transverse section of the same.
Figure 3 is a transverse vertical section of a modified form of the vulcanizer.
In the said drawings, figures 1 and 2, A designates a cylindrical chamber and
B a similar chamber, or shell, surrounding the chainber A; the two ends of the latter
extending somewhat beyond the shell B, and an annular space being left between
the walls of the two structures. Beneath the middle of shell B is placed a
combustion-pit C containing a suitable grate and opening at its top into the space
between the two walls. D, D, designate two flues opening from the upper part of
shell B and communicating at their upper ends with a central flue E. F designates
a steam-pipe passing downward through the two walls and entering within the
chamber A. At its lower end this pipe is bent so as to extend horizontally, along
the bottom of the chamber A; the bent portion being perforated throughout its
length so as to emit numerous jets into the chamber A. The pipe F is supposed
to lead from a suitable steam boiler and is provided with a valvef to regulate the
admission of steam. G designates a pipe extending out of the bottom of
chamber A and through shell B., This pipe serves as a blow-off and is provided
with a valve g to regulate the escape of steam from chamber A. At one end of
chamber A is placed rigid head H while at the opposite end is placed a swinging
head I secured to the wall of the chamber by hinge-bolts i, so as to permit the
opening of the chamber for the reception and withdrawal of the rubber; a caster i¹
being secured to the lower part of head I to sustain its weight when closed.
K designates a bed for supporting the vulcanizer, L a gauge for indicating the
pressure of steam within chamber A, and M a thermometer for indicating the
temperature within said chamber.
The above described structure is that of the larger and stationary vulcanizers,
but I have also shown a smaller portable form in figure 3. In this figure
N designates the frame of the vulcanizer in the upper part of which is set the
vulcanizing chamber O. The upper part of this chamber is formed with a flange,
by which the chamber is supported in the frame N, and within this flange is formed
a channel o communicating with the interior of the chamber by a port o¹. The
top P of this chamber is removable so as to admit the rubber either in mass or in
moulds as shown; screws p, p, being used to hold the moulds when placed in
the chamber. R designates a coil of pipe perforated within frame N and communi-
cating with a suitable supply of gaseous or liquid fuel; the jets of flame being
directed upward toward the chamber O. S designates the steam supply pipe which
communicates with channel o. T designates the pressure gauge, U the safety valve,
V the blow-off, and W a valve for controlling the admission of steam from channel o
into chamber O through port o¹.
The operation is as follows; after steam has been generated in the boiler, the
auxiliary furnace C or N is lighted and the temperature of the vulcanizing
chamber is raised to a temperature sufficient to prevent condensation of steam. As
soon as this is accomplished the steam is admitted into the chamber and surrounds
the rubber acting to vulcanize the same. When the vulcanizing process has been

page_text: completed the blow-off is opened, the inlet is closed, and the rubber is removed.
The inlet valve, the gauge, and the thermometer all combine to ensure perfect
uniformity in the operation and no blistering, burning, warping, or marking
can occur.
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
1st The improved method herein described for vulcanizing rubber, the same
consisting in subjecting the rubber to the action of steam within a receptacle
subjected to beat externally from an auxiliary furnace to prevent condensation.
2nd An improved vulcanizer consisting of a vulcanizing chamber communicating
with a steam generator and provided with an auxiliary furnace for heating the
chamber from without, to prevent condensation of steam, as described.
3rd The vulcanizer consisting of the chamber A having the steam inlet and the
chamber B having the auxiliary furnace C and surrounding chamber A, as
set forth.
4th The combination with the chamber A with its pipes F, G, and heads H, I,
of the shell B with its flues D, E, and the furnace C, as specified.
5th The combination with the chamber A, shell B, and furnace C, of the steam
inlet F, steam outlet G, flues D, E, gauge L, thermometer M, and heads H, I, as
described.
Gth The combination with the frame N having coil R, of the chamber O having
the channel o and port o', the steam inlet S, gauge T, safety valve. U, blow-off V,
and valve W, as set forth.
In witness whereof I, the said Frederick Wheaton Seabury, have hereunto
set my hand and affixed my seal at Providence, in the County of Providence,
State of Rhode Island; United States of America, this 20th day of May, in
the year of our Lord one thousand eight hundred and eighty-five.
Signed in presence of:
JOSEPH A. MILLER, Jr.,
Patent Solicitor,
°
Providence, R.I., U.S.A.
FREDERICK WHEATON SEABURY.
Haseltine, Lake & Co.,
Agents.