Year: 1886

page_text: Date of Application, 7th May, 1886.
Complete Left, 5th Feb., 1887.
Complete Accepted, 8th Mar., 1887.
1, ALEXANDER TURNBULL, of 139 Brook Street, Glasgow, in the County of
Lanark, North Britain, Engineer, do hereby declare the nature of this Invention to
be as follows, that is to say:
My said Invention relates to twin safety valves such as are used, although not
exclusively, for locomotive boilers, and which are loaded with a single spring for
cach pair of valves; and the object of my present improvements is to provide means
for insuring the joint and equal action of the two valves of a pair, so that when
steam blows off the full relief of which the two valves are together capable may be
obtained.
In carrying out my Invention the valve seats and valves are arranged in a valve
box bolted to the boiler, and which has formed or fixed on it two funnels for the
escape of the steam. The valves are pressed down by spindles which extend up
through the funnels and have their upper ends pressed on by a cross bar or lever to
the middle of which the upper end of the spring is connected the lower end of the
spring being connected to the valve box at a point between the bases of the two
funnels. The upper end of the spring is hooked on the middle of a horizontal pin
and between the sides of a forked piece fixed to the cross bar and the pin has screw
threads formed on its ends to fit internally screwed eyes in the sides of the forked
piece, the pin being parallel to the cross bar. The pin has a groove turned at its
middle to receive the hook of the spring; and by screwing it one way or the other,
the effective point of action of the spring on the cross bar can be very accurately
adjusted so as to equalise the action on the two valves.
In order to further insure the equal action of the two valves, the openings from the
valve box into the two funnels are made of a limited size, and the valves are made
with flanges which occupy these openings to a greater or less extent when the valves
are closed but allowing free egress to the steam when the valves are lifted. With this
arrangement should one valve lift before the other the steam in the box will act on
the upper flange of the latter and assist it to open.
BDMUND HENT
EDMUND HUNT,
Applicant's Agent.

page_text: I, ALEXANDER TURNBULL, of 139 Brook Street, Glasgow, in the County of
Lanark, North Britain, Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, that is to say :-
My said Invention relates to twin safety valves such as are used, although not
exclusively, for locomotive boilers, and which are loaded with a single spring for each
pair of valves; and the object of my present improvements to provide means for
insuring the joint and equal action of the two valves of a pair, so that when steam
blows off, the full relief of which the two valves are together capable, may be obtained.
And in order that my said Invention and the manner of performing the same may
be properly understood I hereunto append a sheet of explanatory drawings to be
hereinafter referred to and showing my improved twin safety valves.
Figure, 1, on the accompanying sheet of drawings is a sectional side elevation and
figure, 2, is a separate view of a detail.
In carrying out my Invention the valve seats, 3, and valves, 4, are arranged in a
valve box, 5, bolted to the boiler, 6, and which has screwed into it two funnels, 7, for
the escape of steam. The valves, 4, are pressed down by spindles, 8, which extend
up through the funnels, 7, and have their upper ends pressed on by a cross bar or
lever, 9, to the middle of which the upper end of the spring, 10, is connected, the
lower end of the spring being connected to a lug, 11, formed on the valve box, 5, at
a point between the bases of the two funnels, 7. The upper end of the spring, 10, is
hooked on the middle of a horizontal pin, 12, (shown separately in figure, 2.) and
between the sides of a forked piece, 13, fixed to the cross bar, 9, by a jam nut, 14, and
pallock, 15, and the pin, 12, has screw threads formed on its ends to fit internally
screwed eyes in the sides of the forked piece, 13, the pin being parallel to the cross
bar. The pin, 12, has a groove turned at its middle to receive the hook of the
spring, 10, and by screwing it one way or the other, the effective point of action of
the spring on the crossbar, 9, can be very accurately adjusted so as to equalise the
action on the two valves.
In order to further insure the equal action of the two valves, 4, the openings from
the valve box, 5, into the two funnels, 7, are made of a limited size, and the valves, 4,
are made with flanges, 16, which occupy these openings to a greater or less extent
when the valves are closed but allowing free egress to the steam when the valves are

page_text: lifted. With this arrangement should one valve lift before the other the steam in the
box, 5, will act on the upper flange, 16, of the latter and assist it to open.
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 :-
1-In twin safety valves fitting the cross bar or lever which bears on the spindles of
the valves, with an adjustable screw pin formed with a groove to receive the hook of
the spring substantially as and for the purposes hereinbefore described.
2 Making twin valves with flanges which when the valves are closed partly close
openings through which escaping steam passes into the discharge funnels substantially
as and for the purposes hereinbefore described.
EDMUND HUNT,
Applicant's Agent.