Improvements in and relating to Apparatus for Stopping Engines.
Year: 1896

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Apparatus for Stopping Engines.
I, GILMAN WELD BROWN, of West Newbury, in the County of Essex and
State of Massachusetts, United States of America, Gentleman, do hereby
declare the nature of my invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to apparatus for shutting off steam from a steam-engine,
and particularly to an emergency shut-off in which a shut-off valve is adapted to
close a steam pipe or conduit, and connected with a piston of larger area than the
valve, said piston being located in a cylinder connected with the conduit. The
steam enters the cylinder around the piston, and balances the latter when there is
no steam outlet from the cylinder; but when an outlet is formed by the opening
of a vent with which the cylinder is provided, the piston is unbalanced and forced
into the cylinder by the steam pressure, which is thus caused to close the shut-off
valve and hold it closed so long as the steam-outlet of the cylinder remains open.
The vent-valve is opened by automatic mechanism when the speed of the engine
becomes excessive, or under other conditions requiring a quick closure of the
shut-off valve.
My invention has for its object to enable an emergency-valve or shut-off of the
character above described to be operated by an attendant, so that the same valve
can be used not only as an automatically operated emergency shut-off, but also in
the same manner as an ordinary screw-valve, to shut off the steam at the will of
the operator. The invention also has for its object to prevent the steam pressure
in the conduit from balancing the piston and thus prematurely opening the shut-off
valve.
The invention consists in an appliance of the character specified, comprising a
casing or conduit having a valve-seat, a shut-off valve in the conduit, and two
independent agencies for operating said valve, one controlled by steam pressure,
and the other by hand, each being capable of operation independently of the other.
The invention also consists in certain improvements incidental to the main objects
of my invention, all of which I will now proceed to describe and claim.
Of the accompanying drawings, forming a part of this specification,
Figure 1 represents a sectional view of a shut-off valve and its casing, provided
with my improvements, the valve being shown in its normal condition, ready to be
closed by steam pressure.
Figure 2 represents a similar view, showing the shut-off valve closed.
Figure 3 represents an end view of the shut-off valve, showing the preferred
means for securing the relief-valve thereto.

page_text: Figure 4 represents a sectional view of the valve and piston.
Figures 5 and 6 represent sectional views of a modification.
The same letters of reference indicate the same parts in all the figures.
Referring to Figures 1 to 4, inclusive,-
a represents a casing comprising an inlet portion 2, and an outlet portion 3, said
portions being adapted to be coupled to sections of a steamn conduit. Between the
portions 23 is a partition having a steam port 4 the margin of which constitutes
a valve-seat 5. b represents a shut-off valve which is movable in the casing and is
adapted to open and close the port. The shut-off valve has a stem or rod 6, to one
end of which is affixed a piston e movable in a cylinder 6, which is formed on the
casing a and communicates with the inlet portion 2 thereof, the piston fitting the
cylinder somewhat loosely, so that steam can leak around the piston into the outer
portion of the cylinder and thus normally balance the plston when there is no outlet
for the steam from the cylinder behind the piston.
The cylinder is provided with a vent or pressure outlet, shown as a tube 7, which
is provided with a valve 8 whereby it may be opened and closed. When the vent
is closed, pressure accumulates in the outer portion of the cylinder, and the piston is
balanced, so that the steam pressure on the under side of the valve 6 opens the
latter. I term the face of the valve which faces the supply end 2 of the casing the
under side, and the other face the upper side.
When the vent is opened, the pressure is relieved at the outer side of the piston,
and the latter is unbalanced and forced outwardly by the pressure in the casing and
is thus caused to close the shut-off valve, the piston c being larger in area than the
valve b. It will be seen, therefore, that the opening of the vent-valve causes the
closing of the shut-off valve. The vent-valve may be opened either automatically,
or, through human agency.
To prevent the accumulation of pressure in the outer portion of the cylinder 6.
and the consequent opening of the shut-off valve by the steam pressure, a result
that would follow the closing of the vent-valve before the hand-operated device
hereinafter referred to is adjusted to hold the valve 6 in its closed position,
I provide means for relieving any pressure that may accumulate in the outer.
portion of the cylinder, so that the steam pressure in the conduit will hold the
valve closed. In the embodiment of my invention now being considered, I show.
the valve-stem provided with a relief-passage extending through the piston
and through the shut-off valve, and a relief-valve 63 arranged to close upon a seat
surrounding said passage at the upper side of the shut-off valve, the arrangement
of said relief-passage and valve being such that the relief-valve will be opened by
any increase of pressure in the outer portion of the cylinder, thus preventing the
piston from being unbalanced by an accumulation of pressure in the outer portion
of the cylinder. Said relief-valve also prevents the passage of steam through the
relief-passage into the outer end of the cylinder 6 when the pressure on the
upper side of the valve is greater than that on the outer side of the pistou.
The relief-valve 63 is here shown as a flat disk held in operative relation to its
seat by means of ears or lugs & formed on the shut-off valve b, said ears permitting.
the necessary play of the relief-valve, but preventing it from being displaced. The
relief valve is preferably provided with recesses 6 corresponding with the ears b
and arranged so that the valve can be inserted in the space between the cars when
the recesses coincide with the ears, the valve being afterward partly rotated to bring
the recesses out of line with the cars, as shown in Figure 3. A screw is then
inserted in the shut-off valve b, in position to engage one of the recesses and
prevent the relief-valve from being turned to bring its recesses into line with the
ears b
So long as the vent-valve 8 remains open and there is no pressure in the
outer portion of the cylinder, the relief-valve is held to its seat by the pressure, in
the casing a, said valve yielding only when pressure accumulates in the outer portion.
of the cylinder.
d represents a hand-operated device whereby the engineer may close the shut-off
valve independently of the pressure-controlled means above described. Said

page_text: device in its simplest form is a rod or stem having a screw-thread engaged with an
internal thread in the casing a and provided at its outer end with a suitable
bandle d. The rod d is arranged so that its inner end projects into the casing in
position to bear upon the relief-valve 6 when the shut-off valve b is opened, as:
shown in Figure 1. The rod d has no positive connection with the shut-off valve.
and therefore permits the latter to be closed by the steam pressure, the shut-off
valve leaving the rod when thus closed, as indicated in Figure 2; hence the rod d.
does not interfere with the steam-pressure control of the shut-off valve. When,.
however, the engineer desires to shut off the steam in the usual manner, he rotates
the rod d in the direction required to force it into the casing, thus causing it to
close the shut-off valve, as indicated by dotted lines in Figure 2, the rod d also
holding the relief-valve to its seat when the shut-off valve is thus closed.
When the rod d is moved outwardly from its valve-closing position, the cylinder-
vent being closed, the steam pressure leaking around the piston allows pressure to
accumulate on the outer side of the piston c, thus balancing the piston and allowing
the pressure on the under side of the valve b to open the valve."
It will be seen that the apparatus above described constitutes at once an
emergency and a hand-operated stop or shut-off, its operation as a hand-operated
shut-off being the same as that of any ordinary shut-off valve, so far as the closing
movement is concerned, while its opening movement is caused by steam pressure,
the two operations being independent of each other, that is to say, the valve can
be closed by steam pressure without movement of the rod d, or by the rod d
without the agency of steam pressure. I do not limit myself to the construction above
set forth, as the object of my invention may be attained by various other mechanical
contrivances.
In Figures 5 and 6, I show a construction in which the valve b and piston care
not positively connected with each other, and are movable independently, the piston
having a-tube c which slides and fits closely in a head 9 at the inner end of the
cylinder 6. The valve b has a tubular stem 67 fitted loosely in the tube c'. When
the valve b is open, as in Figure 5, and the vent-tube 7 is closed, the piston c is
balanced by the steam leaking through the tube c' and around the piston, the
valve b being therefore held open by the steam pressure in the conduit. When the
vent-tube 7 is opened, the piston is unbalanced and is forced inwardly, or toward
the valve-seat; by the steam pressure, its tube c¹ bearing on the valve b and forcing
the latter.to its seat, where it is held by the steam pressure, so long as the vent-
tube remains open (see Figure 6). The valve-closing rod d is arranged to bear on
the end of the stem b', and may be adjusted to close the valve while the piston is in
the position shown in Figure 5, without moving the piston, the valve and its stem
being movable independently of the piston.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. An appliance of the character specified, comprising a casing or conduit having
a valve-seat, a shut-off valve in the conduit, and two independent agencies for
operating said valve, one controlled by steam pressure and the other by hand, each
being capable of operation independently of the other.
2. An appliance of the character specified, comprising a casing or conduit, a
shut-off valve therein, means substantially as described for causing the steam
pressure to either close or open the shut-off valve, and a hand-operated valve-
closing device operatively engaged with the casing and separable from the valve.
3. An appliance of the character specified, comprising a casing or conduit having
a valve-seat, and a cylinder communicating with the conduit at one side of the
valve-seat, said cylinder having a vent, a shut-off valve in the conduit, a piston
movable in the cylinder and connected with the shut-off valve, and a relief-valve
adapted to prevent an accumulation of pressure in the cylinder.
4. An appliance of the character specified, comprising a casing or conduit having
fä

page_text: a valve-seat, a cylinder communicating with the conduit at one side of the valve-
seat, and having a vent, a shut-off valve movable in the casing to open and close
the valve-seat, a piston movable in the cylinder and connected with the shut-off
valve, a relief-passage extending through the pistou and shut-off valve, a relief-
valve controlling said passage and adapted to yield to prevent an accumulation of
pressure in the cylinder, and a hand-operated valve-closing device having an
operative engagement, such as a screw-threaded connection, with the casing, and
arranged to bear loosely on and close the relief-valve and the shut-off valve.
Dated this 22nd day of July 1896.
GILMAN WELD BROWN.
Haseltine, Lake & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.