IMPROVEMENTS IN SAFETY VALVES
Year: 1877

page_text: LETTERS PATENT to Alexander Turnbull, of Glasgow, in the County of Lanark,
North Britain, Engineer, for the Invention of "IMPROVEMENTS IN SAFETY
VALVES."
Sealed the 5th February 1878, and dated the 19th October 1877.
PROVISIONAL SPECIFICATION left by the said Alexander Turnbull at the
Office of the Commissioners of Patents on the 19th October 1877.
ALEXANDER TURNBULL, of Glasgow, in the County of Lanark, North Britain
Engineer. "IMPROVEMENTS IN SAFETY VALVES."
This Invention has for its object to still further improve the action of safety valves
of the kinds described in the Specification of Letters Patent granted to the present
applicant, and dated 18 October 1876, (No. 4017), and the present improvements are
also applicable to other kinds of safety valve.
In carrying out the present Invention according to one modification, the valve
which is in the shape of an inverted cup is formed or fixed on the lower end of a
vertical spindle extending upwards through a vertical pipe through which steam or
other fluid passing the valve escapes.
An enlargement or chamber is by preference formed at the lower end of the pipe
and surrounding the valve, and the valve is enlarged externally above its contact
edge or face, the enlarged part just entering the throat or lower end of the vertical
pipe when the valve is closed. The valve is guided by external guides formed or
fixed on the valve seat or at the bottom of the vertical pipe, also by its spindle
passing through a guide eye in a bridge above. The steam or fluid in escaping
enters the vertical pipe through the annular space between the valve and the pipe,
and immediately passing into the larger area between the spindle and pipe has no
tendency to induce pressure on the top of the valve, but rather the reverse.
The full diameter of the valve may be continued any distance up the vertical
pipe, but in that case the pipe is by preference enlarged in diameter above the
throat or bottom end.

page_text: The improved valve may be loaded in various ways, but by preference a pipe
carrying annular weights and put over the vertical discharge pipe, is at its upper
end connected to the valve spindle by a bridge-piece.
For easing the valve an eccentric or cam is provided on a horizontal spindle
placed in a radial or nearly radial position, so that the eccentric when turned to
raise the weights also carries them round a short distance, and the valve moving
with them has its position on the seat changed thereby.
The valve of the arrangement herein-before described may be modified by forming
a cup on the upper side of it, either in addition to or instead of the inverted cup
or internal hollow, or the valve may be made without the internal hollow, but with
a part above the contact edge or face considerably larger than the spindle, and such
as to form a comparatively narrow annular space for the passage of the steam or
fluid at the lower part of the vertical pipe; and in some cases the vertical pipe may
be considerably shortened, or a simple contraction of the chamber round the valve
may be substituted for it.
Another improvement consists in fitting the valve with inclined flanges or blades
in order that whenever the steam or fluid passes the valve it may turn the valve.
These blades may be internal or external, or both, and near the contact edge or face
or on the spindle in or above the vertical discharge pipe where they will assume a
helical form, and assist in keeping the valve open by the upward impact of the
steam or fluid on them.
When the valve is arranged to rise into a cylinder or recessed guide, so that the
escaping steam or fluid cannot act on the top of it, but has egress by lateral or
other openings, a small aperture is made in such cylinder or recessed guide to
prevent the accumulation in it of steam or fluid which may get past the guiding
surfaces.
When the valve is made to rotate by the action as herein-before described of the
escaping steam or fluid on inclined flanges or blades, it may be arranged to sound
a bell by projections on any part which strike the bell when the valve rotates.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Turnbull in the Great Seal Patent Office on the 17th
April 1878.
ALEXANDER TURNBULL, of Glasgow, in the County of Lanark, North Britain,
Engineer. "IMPROVEMENTS IN SAFETY VALVES."
My said Invention has for its object to still further improve the action of safety
valves of the kinds described in the Specification of Letters Patent granted to me,
and dated 18 October 1876 (No. 4017), and my present improvements are also
applicable to other kinds of safety valve.
My present Invention comprises several modifications, each forming a combi-
nation of one or more new or improved and useful features with parts already
known.
The principal modifications or combinations are shown on the accompanying two
Sheets of explanatory Drawings, and the nature of my said Invention and the
manner of performing the same will be most readily understood if I at once proceed
to particularly describe the several modifications with reference to the said Drawings
on which the same reference numerals are used to mark the same or like parts
wherever they are repeated.
A first modification of my improved safety valves is shown in vertical section in
Figure 1 on the accompanying Sheet of Drawings, Figures 2 and 3 being hori-
zontal sections, as at the lines A-A and B-B respectively in Figure 1. The
valve 1 is in the shape of an inverted cup, and is formed or fixed on the lower
end of a vertical spindle 2 extending upwards through a vertical pipe 3, through
which pipe steam or other fluid passing the valve 1 escapes.
An enlargement or chamber 4 is formed at the lower end of the pipe 3, and
surrounding the valve 1, the seat 5 of which projects a little above the bottom of
the chamber. The valve 1 is enlarged externally above its contact edge or face,
the top of the enlarged part just entering the throat or lower end of the vertical
pipe 3 when the valve is closed. The valve 1 is guided by the inner edges of radial
guides 6, formed externally to the valve on the valve seat 5, also by its spindle 2
passing through a guide eye in a bridge 7 crossing the pipe 3 above. The steam or
fluid first escapes into the chamber 4, and then enters the vertical pipe 3 through
the annular space between the valve 1 and the bottom of that pipe, and immedi-
ately passing into the larger area between the spindle 2, and the sides of the pipe
has no tendency to induce pressure on the top of the valve, but rather the reverse.
The valve is loaded by directly acting annular weights 8, carried by a pipe 9, put
over the discharge pipe 3, and formed with internal radial arms 10, and a central
eye by which it is fixed upon the valve spindle 2.
For casing the valve an eccentric or cam 11 is provided on a handled horizontal
spindle 12, placed in a radial or nearly radial position, so that the eccentric 11 when
turned to raise the weights 8, also carries them round a short distance, and the
valve 1 moving with them has its position on the seat changed thereby.
The valve 1 is formed with inclined or helical flanges or blades 13 at the part
entering the bottom of the discharge pipe 3, in order that whenever the steam or
fluid escapes it may turn the valve by acting on such inclined blades 13. The
radial arms 10 of the weight pipe 9 are also made helical or inclined to occasion
increased turning action, which may be further increased by giving a reversed
helical form or inclination to the bridge 7 of the discharge pipe 3, so that the issuing
steam may be thereby directed more effectively on the arms 10.
In some cases, as for example, when it is wished to lead away the escaping steam
or fluid by a pipe, the valve apparatus shown in Figure 1 may be modified by
closing the top of the pipe 3, and by forming a lateral outlet, as indicated by dotted
lines below the weight pipe 9, this weight pipe being, if necessary, fixed in a higher
position on the valve spindle.

page_text: A second modification, shown in elevation in Figure 4, and in horizontal section in
Figure 5 (as at the line C-C in Figure 4), differs from the first modification only in
the mode of loading the valve, this being done by two helical springs 14 connected
at their upper ends to a cross bar 15, which bears on the top of the valve spindle 2.
The bottom ends of the springs 14 are connected to screwed bolts 16, held by
adjustable screw nuts in lugs cast on the valve chest 17. In this modification, as in
the first, the top of the pipe 3 may be closed, and a lateral branch may be formed as
indicated by the dotted circles in Figure 4, for the attachment of a waste steam
pipe.
In the third modification, shown in vertical section in Figure 6, and in horizontal
section in Figure 7 (as at the line D-D in Figure 6), a side pipe 18 is provided for
the discharge of the steam or fluid, and the top of the valve 1 moves through a
cylindrical or recessed guide 19, fixed in the top of the chamber 4, so that the steam
or fluid cannot act on the top of the valve. The guide 19 is made a quite easy fit
to the valve 1, but any steam or fluid passing it gets freely away by the vertical
pipe 3, and between it and the weight pipe 9. The valve 1 has formed or fixed on
it curved inclined blades 13, on which the steam or fluid acts when escaping, and
thereby turns the valve.
The fourth modification shown in sectional elevation in Figure 8, and in hori-
zontal section in Figure 9 (as at the line E-E, in Figure 8). In this case a pair of
valves 1 are combined upon one casing 17, but each with a separate chamber 4 and
discharge pipe 3. Both valves are loaded by means of one cross bar 15, connected
to two adjustable helical springs 14, the arrangement being such that one valve will
help the other should one from any cause not open quite so easily as the other. The
bar 15 is lengthened to form an easing lever, and the spindle 2 of one valve acts as
the fulcrum when the lever is used to ease the other valve.
The fifth modification shown in vertical section in Figure 10, and in horizontal
section in Figure 11 (as at the line F-F, in Figure 10) is a simplified modification
in which the discharge pipe (3) is dispensed with, whilst the chamber 4 with the
contraction at its top, and the external radial guides 6 are formed in the same casting
with the valve seat 5. The valve is loaded in the same manner as in the second
modification, the cross bar 15 being made with a central nipple to bear on the
bottom of a small recess formed on the top of the valve 1.
In the sixth modification shown in vertical section in Figure 12, the full outer
diameter of the valve 1 is continued some distance up the discharge pipe 3 in the
form of an open-topped cylinder 20, which not only prevents the escaping steam or
fluid from increasing the pressure on the top of the valve, but rather tends to a
diminution of that pressure so as in the case of a spring loaded valve to compensate
for the increasing pressure of the spring as the valve opens. This cylinder 20 is
utilised by placing the spring inside it, the pressure of which spring is adjusted by
means of a screw gland 21 tapped through the eye of the bridge 7. The upper part
of the discharge pipe 3 is widened to compensate for the central space taken up by
the gland 21.
The seventh modification shown in vertical section in Figure 13 is like the third
modification excepting that it is loaded by a spring 22 contained in a cylinder 23
above the casing 17. The spring is adjusted by means of a screw gland, and a
cover 24 is added, which can be locked, and which has fitted to it a hollow piece 25
with handles for turning it by, and with a collar so that it can be raised by an
easing lever. The piece 25 is guided by an elongated tube or boss formed on the
screw gland 21 by means of which the spring is compressed. The valve spindle 2
extends up inside the piece 25, and has a slot formed through it near its upper end,
for a cross key which connects it to the piece 25. A small passage is formed from
the space immediately above the valve 1 into the discharge pipe 18, to allow
of any steam or fluid passing the guide 19 being drawn off into the main current;
or a small outlet for steam or fluid may be made from the space above the valve
directly into the atmosphere.
In the eighth modification, shown in vertical section in Figure 14, the valve 1,

page_text: which is shown in horizontal section in Figure 15, is made with curved inclined
flanges or blades 13, placed so as to be impinged on by the steam or fluid as it issues
between the valve and seat. The series of blades 13 have above and below them
annular plates, which by slightly confining the steam or fluid, make it act more
effectively on them to turn the valve. The valve is loaded by a weight 26 applied
directly to it inside a casing 23, and an alarm bell 27 is fixed at the top of
the casing, and is provided with a clapper to be acted on by one or more
arms 28 fixed on the valve spindle 2 which projects through the top of the
casing 23, so that whenever the steam or fluid escapes to an extent sufficient
to turn the valve by acting on the blades 13 it will cause the alarm bell 27 to
be sounded.
A ninth and last modification is partially shown in vertical section in Figure 16. It
is loaded by a direct-acting spring 22, like the seventh modification (or it might be a
weight 26, as shown in Figure 14). The guide 19 is dispensed with, the valve
spindle 2 being guided by the bottom of the spring case 23, and by the spring-
compressing gland (21) at a higher part. The escaping steam passes from the
chamber 4, first upwards through a contracted annular space, as in the fifth (Figure
10) and other modifications, and then downwards through an annular space 29 to
the outlet branch pipe 18. The annular outlet at the top of the chamber 4 is slightly
larger at its upper part, and the downwardly projecting boss on the bottom of the
spring case 23 is at its bottom of slightly smaller diameter than the upper part of
the valve 1, in consequence of which the escaping stean has little or no tendency to
get into the spring case 23. The shell forming the outside of the chamber 4 may
be a separate piece or in the same casting with that comprising the spring case 23,
and part of the passage 29; and instead of this passage 29 extending entirely round
at its lower part, it may communicate with the bottom casting by two or more
separate openings. The joint 30, between the upper and lower castings is made at
a level a little below that of the top of the valve seat 5, to give facilities for refacing
the valve seat.
In each of my modifications of safety valve shown on the accompanying Drawings,
and herein-before described, the mode of applying the load may be changed to any
mode that is suitable in the other modifications, or to any other suitable mode.
I prefer to make the valve 1 in the form of an inverted cup, as shown, but my
various improvements are also advantageously applicable with the common or other
form of valve. The contact surfaces of the valve and seat may be flat, or conical,
or spherical; and when the contact surfaces are spherical, the valve may be of the
pendulous kind, loaded either internally or externally.
Every one of the modifications may be fitted with the helical, inclined, or
curved blades (13) for the purpose of causing the valve to turn when the steam
or fluid escapes; and such blades may be arranged in a variety of way besides
those herein-before mentioned; thus, they may be arranged inside the valve,
or the seat instead of or in addition to there being such blades outside the valve.
The several features or peculiarities of the modifications shown on the accom-
panying Drawings, and herein-before described, may be interchanged, so that
additional combinations may be formed, each comprising one or more of my
improvements.
Having thus particularly described my said Invention, and the manner of per-
forming the same, I have to state that what I believe to be novel and original, and
claim as the Invention secured to me by the herein-before in part recited Letters
Patent, is,―
1. Each of the nine combinations of parts forming a safety valve with its
accessories, substantially as shown on the accompanying Sheets of Drawings, and
herein-before described.
2. The combination of the chamber (4) surrounding the valve (1), with a con-
tracted annular opening leading from the top of the chamber into a vertical discharge
pipe (3), or directly into the atmosphere, as herein-before described.
3. The forming of the valve (whether having an inverted cavity or not) with an

page_text: enlargement above the contact surface, such enlargement moving up into a guide, so
that the issuing steam or fluid has not access to the top of the valve, excepting to
the small extent of what passes the guide, and for which an outlet is provided, sub-
stantially as herein-before described.
4. The easing gear with an eccentric or cam (11) arranged to turn the valve
when lifting it, as herein-before described.
5. The application of helical, curved, or inclined blades to safety valves, in order
that the escaping steam or fluid may act on them, so as to turn the valves, as herein-
before described.
6. The mode of loading a pair of valves with one cross bar and two external
springs, as herein-before described with reference to Figures 8 and 9 of the accom-
panying Drawings.
7. The combination of a bell or gong with a safety valve, which rotates when the
steam or fluid escapes, as herein-before described.
In witness whereof, I, the said Alexander Turnbull, have hereunto set my
hand and seal, this Sixteenth day of April, in the year of our Lord One
thousand eight hundred and seventy-eight.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
ALEXANDER TURNBULL. (L.S.)