IMPROVEMENTS IN GOVERNORS FOR VULCANIZING APPARATUS
Year: 1881

page_text: LETTERS PATENT to Alexander Melvillo Clark, of 53, Chancery Lane, in the
County, of Middlesex, Patent Agent, for an Invention of "IMPROVEMENTS
IN GOVERNORS FOR VULCANIZING APPARATUS." A communication from
abroad by William Evelyn Gwyer, of the City, County, and State of New
York, United States of America.
COMPLETE SPECIFICATION filed by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 14th March 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN GOVERNORS FOR VULCANIZING
APPARATUS." A communication from abroad by William Evelyn Gwyer, of the
City, County, and State of New York, United States of America.
With vulcanizers in which the required temperature is obtained by confining the
steam, especially those used by dentists, the proper regulation of the temperature
is of the utmost importance, and has heretofore been attended with difficulty. The
usual method is to regulate the flow of gas to the steam generator by hand, but such
method is unreliable.
The present Invention has for its object the automatic regulation of the flow of
gas by a governor worked by the steam pressure, whereby the pressure, and
consequently the temperature, shall be maintained at a nearly uniform point.
Further, the object of the Invention is to allow the escape automatically from the
steam space or steam generator of expanded air, which interferes with the proper
indication of pressure if allowed to remain.
The Invention consists in a gas cock opened by a spring and closed by steam
pressure for regulation of the flow of gas, and also in a relief cock or valve
combined with the apparatus for allowing escape of air.
In the accompanying Drawing Figure 1 is a sectional elevation of the governor
in which a flexible diaphragm is used; Figure 2 is a face view of the same;
Figure 3 is a cross section of the gas cock; and Figure 4 is a sectional elevation of

page_text: the governor in a modified form. Similar letters of reference indicate corresponding
parts.
•
A is a hollow plug adapted for connection by a pipe or otherwise, with the shell
of the steam box of the vulcanizer (shown by dotted lines), which is of usual.
construction. The upper end of the tube is formed or fitted with a chambered
enlargement a of circular form, in which a circular flexible diaphragm b of ordinary
character is held by the face plate c that covers the chamber; g is a lever pivoted
on the face plate c and fitted with a screw h that extends through a central
aperture in plate c and bears upon the diaphragın b; i is the gas cock fitted in the
gas supply pipe k between the source of supply and the burners (not shown), and
having its stem d connected with the lever g. The valve shown is constructed to
cut off and open the gas pipe by a limited extent of movement, for which purpose
the valve case 7 separates the gas pipe, and the separated ends connect with
passages m, m, (Figure 3) that extend to the face of the valve seat. The valve n is
a disc on the end of stem d which carries a spiral spring e tending to retain the
valve off its seat, and thus allow communication between the passages m. The
passage in plug A communicates with the space at the back of diaphragm ỗ so that
the steam has access thereto, and it will be seen that the tendency of pressure on
the diaphragm is to move the lever g outward, thus moving stem d in the direction
to close the valve to its seat. At one side of plug A and communicating with the
passage therein the relief cock B is placed. This cock consists of a chambored
case o in which is fitted a disc valvo p having a stem q that extends through a
central aperture in the cap o' of the valve case. The stem q is grooved lengthwise,
૧
as shown at q¹, to allow escape of air from the case. The valve p has suitable
packing on its face to close tightly against the underside of cap o', and the valve
is placed to fall and open the passages q¹ by gravity.
In operation, the burners being lighted under the generator, the air therein or in
the steam space of the vulcanizer is first heated and by its expansion passes
through the cock B until the steam pressure is sufficient to close the valve p, by
which time the air will have nearly all escaped. As the pressure of steam increases
the lever g is moved by the action of diaphragm b until the pressure reaches the
point at which the apparatus is set when the valve n will have checked the flow of
gas to the minimum amount. The heat of the generator being thus reduced the
steam pressure falls, diaphragm 6 reacts, and the gas cock opens. There may be a
loose connection between lever g and stem d so that the lever can move a certain
distance before moving the stem. The diaphragm 6 will act correctly according to
steam pressure on account of the absence of expanded air, which in the comparatively
small steam space of a vulcanizer is an important factor of pressure. The correct
ratio between pressure and heat can therefore be obtained.. A. cock r is fitted in
the coupling thimble of cock B so that the passage can be closed by hand if desired.
This is done when steam is raised in order to prevent wear of the relief valve and
leakage of steam. It is evident that the cock 7 may be used as a substitute for the
automatic valve, but attention by the operator will be required for opening and
closing it at proper times.
8
The governor shown in Figure 4 is modified in respect to the device used for
receiving the steam pressure actuating the gas cock. At the end of screw plug A
is fixed a "Bourdon" spring C, the same being a flat tube bent in semicircular form
having its outer end closed and terminating above the gas cock i. On the outer
end of valve stem d a rod & is connected by a swivel joint, and this rod is connected
by a turn-buckle t with the free end of spring C. The turn-buckle allows adjust-
ment of the valve so that it shall be retained normally open by spring e, and until
expansion of spring C by the steam pressure passes a given point. In operation
the curve of the hollow spring C is enlarged in proportion to steain pressure, and
when the pressure passes beyond the point at which the governor is set, the valve
is raised and checks the gas in the same manner as before described.
Having described the nature of the said Invention and the manner of performing

page_text: the same, I declare that what I claim as new and desire to secure by Letters
Patent is,
1st. In governors for vulcanizing apparatus, the combination of a spring opened
gas cock or valve, and a spring fitted for movement by the pressure in the steam
box to close the cock, substantially as shown and described.
2nd. The combination with the gas supply pipe of vulcanizing apparatus of a
cock or valve fitted for being closed by connections actuated directly by the
pressure in the steam box, substantially as shown and described.
3rd. The flexible diaphragm b, lever g, and gas cock having its stem connected
with the lever, combined together and with hollow plug A adapted for connection
to the shell of a vulcanizer, substantially as shown and described.
4th. The governor for vulcanizers consisting of the hollow spring C, gas cock or
valve i, turn-buckle connections t, gas pipe k, and hollow plug A, substantially as
shown and described, combined for operation as set forth.
5th. The combination with governors for vulcanizers actuated by steam pressure
of an automatic relief cock or valve for escape of air from the steam space,
substantially as shown and described.:
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Fourteenth day of March, A.D. 1881.
A
T Aם