IMPROVEMENTS IN VALVES FOR THE AIR PUMPS OF STEAM ENGINES
Year: 1878

page_text: LETTERS PATENT to James Lumsden Cunliffe, of Port Glasgow, in the County
of Renfrew, North Britain, Engineer and Ship Builder, for the Invention of
IMPROVEMENTS IN VALVES FOR THE AIR PUMPS OF STEAM ENGINES." A com-
munication from abroad by James Richard Thomson, of Callao, Peru.
Sealed the 4th February 1879, and dated the 9th August 1878.
PROVISIONAL SPECIFICATION left by the said James Lumsden Cunliffe ai
the Office of the Commissioners of Patents on the 9th August 1878.
JAMES LUMSDEN CUNLIFFE, of Port Glasgow, in the County of Renfrew, North
Britain, Engineer and Ship Builder. IMPROVEMENTS IN VALVES FOR THE AIR
PUMPS OF STEAM ENGINES." A communication from abroad by James Richard
Thomson, of Callao, Peru.
This Invention has for its object to improve the action and increase the dura-
bility of the air pump valves of steam engines, and its application is specially of
advantage in the case of large engines driven at comparatively quick speeds, such
as those employed for marine propulsion.
The Invention consists mainly in employing groups of comparatively small
metallic valves of an improved construction, instead of either, the single large
metallic valves formerly used for the purpose, or the smaller rubber valves which
have been more recently used. but which, whilst admitting of increased speed,
have involved great expenditure for renewals on account of their very deficient dura-
bility.
The improved valves are simple lift valves opening and closing by the action of
the currents caused by the air pump or pumps. their closing action being assisted
by springs when they are arranged to open otherwise than upwards. They consist
according to the present Invention of flat or convex discs of brass or other suitable
metal or metals, and are mounted or guided upon fixed central spindles. They
are formed by preference with narrow flat bearing surfaces and close upon flat

page_text: In some modifications the seats are formed in annular grooves made in the seat
plates, rings of lignum vitæ, or wood, or rubber, or vulcanite, or clamite, or other
suitable dense non-metallic substance being fixed in the grooves for the bearing
surfaces or edges of the valves to strike upon in closing. Or such rings of dense
non-metallic substance may be fixed upon the valves instead of upon the scats.
In another modification a narrow ring of rubber is fixed on the outside of each
valve at the edge, so as when the valve is closed, to fill the angle between the
bearing rim of the valve and the outer part of the seat, this ring acting as a flexible
lip, which through the action of the pressure on it will effectually prevent leakage;
or the added ring may be of thin steel or other metal or alloy, having sufficient
clastic flexibility to be closed tightly by the pressure; and instead of attaching
such ring, whether of rubber or thin metal, to the outside of the valve it may be
fixed upon what would otherwise be the contact or bearing surface of the valve,
being, by preference, of such a width that part of it will project to form the lip.
In some cases the ring of rubber or thin metal may be fixed on the valve Seat,
instead of the valve.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Lumsden Cunliffe in the Great Seal Patent Office on the 7th
February 1879.
JAMES LUMSDEN CUNLIFFE, of Port Glasgow, in the County of Renfrew, North
Britain, Engineer and Ship Builder. IMPROVEMENTS IN VALVES FOR THE AIR
PUMPS OF STEAM ENGINES." A communication from abroad by James Richard
Thomson, of Callao, Peru.
The said Invention has for its object to improve the action and increase the dura-
bility of the air pump valves of steam engines, and its application is especially of
advantage in the case of large engines driven at comparatively quick speeds, such
as those employed for marine propulsion.
The Invention consists mainly in employing groups of comparatively small
metallic valves of an improved construction, instead of either the single large
metallic valves formerly used for the purpose, or the smaller rubber valves which
have been more recently used, but which, whilst admitting of increased speeds.
have involved great expenditure for renewals on account of their very deficient dura-
bility.
The improved valves are simple rigid lift valves opening and closing by the
action of the currents or pressures caused by their pumping action, their closing
action being assisted by springs when they are arranged to open otherwise than
upwards. The valves are formed by preference with narrow flat bearing surfaces;
and in some modifications the seats consist of flat-surfaced rings of lignum vitæ, or
wood, or rubber, or vulcanite, or clamite, or other suitable dense non-metallic sub-
stance. Or such rings may be fixed to the valves, and the seats be of metal.
In other modifications rings of rubber or of thin steel or other metal or alloy
are fixed to the edges of the valves, or of the seats. to act as flexible lips, and
effectually prevent leakage when the valves are shut.
And in order that the said Invention and the manner of performing the same
may be properly understood hereunto append two Sheets of explanatory Drawings,
to be herein-after referred to, and representing various modifications of the improved
valves.
In these Drawings the same reference numerals are used to mark the same or like
parts wherever they are repeated.
Figure and 2 on Sheet 1 of the accompanying Drawings are vertical and
horizontal sections of a steam engine air pump as fitted with a modification of the
improved valves, these valves being arranged to open upwards in this example.
and the pump being of the single-acting valved bucket class.
Figure 3 is an elevation of an air pump of the double-acting solid piston class.
with the cover of the valve chambers removed to show the valves: and Figure 4 is
a horizontal section corresponding to Figure 3.
Figures 5 to 15 on Sheet 2 of the Drawings are enlarged sections of various
modifications of the valves. those shown in Figure 5 being of the kind fitted to the
air pump. shown in Figures 1 and 2, whilst those fitted to the air pump, shown in
Figures 3 and 4. are of the same kind, but provided with springs, as shown in
Figure 14.
In carrying out the Invention the air pump (Figures 1 and 2) instead of, as formerly.
having a single large metallic discharge valve at the top is fitted with a group of
five small rigid metallic valves 16: and in a similar way the bucket 17 is fitted
with five small rigid metallic valves 18. while the foot valves are also five small
rigid metallic valves 19. Similar metallic foot and discharge valves 19, 16, arc
fitted to the air pump, shown in Figures 3 and 4.
The valve shown in Figure 5, which is, made of brass or other suitable metal or
alloy, is in a circular form with an annular concavity on its under side. It is held
in position and guided in its movement by a central spindle or stud 20 fixed in the
centre of the valve grating.

page_text: The valve is made with a narrow flat bearing surface 21 round its edge to close
upon a flat metallic seat 22.
The modification of valve shown in Figure 6 is fitted with a ring 23 of a suitable
non-metallic substance, such as is herein-before specified or indicated, such ring 23
closing on a metallic seat 22. A similar non-metallic ring 24 is also fitted at the
eye of the valve.
The modification shown in Figure differs from that shown in Figure 6 in
having the non-metallic rings 23. 24, fixed in the valve seats instead of in the
valve.
The valve shown in Figure 8 is fitted with a conical band 23 of rubber or thin
metal. The metallic seat. 22 is raised and made conical externally so that the
band 23 fits on it when the valve is closed.
The band 25 of rubber or thin metal may be of a cylindrical form, as shown in
Figure 9, the valve seat 22 is however by preference made slightly conical exter-
nally, as shown.
In the modification shown in Figure 10 a flat ring 26 of thin metal is fixed to
the under side of the edge of the valve, and is made of a size to project beyond the
edge, so that the pressure may act on its upper side and tend to make it bear down
tightly on the seat when the valve is closed.
The flat ring 26 of thin metal may be fixed to the seat 22, as shown in Figure 11.
instead of to the valve, and in this case both ring and valve are made to project.
beyond the outside of the seat, so that the pressure may act on the under side of
the projecting part of the ring.
Figure 12 represents a modification in which the opening through the centre of
the valve is avoided, a central guide socket 27 with closed bottom being formed
in the valve, whilst the central guide spindle or stud 28 is fixed in a bridge or
cover 29 above the valve.
Other modes of guiding the valve without forming a central eye through it are
shown in Figures 13 and 15, inner or under guide feathers 30 being adopted in one
case, and outer or upper guide feathers 31 in the other.
Having thus particularly described the said Invention and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise details
herein described or delineated, but that what I believe to be novel and original
and claim as the Invention secured to me by and in terms of the herein-before in
part recited Letters Patent is.-
1. The fitting of rigid metallic valves, such as are herein-before described, to or in
connection with the air pumps of steam engines.
2. The making and fitting of air pump valves in any of the modes herein-before
described with reference to Figures 6 to 11, irrespective of the modes of guiding
such valves.
In witness whereof, 1. the said James Lumsden Cunliffe, have hereunto set my
hand and seal, this Sixth day of February, in the year of our Lord One
thousand eight hundred and seventy-nine.
JAMES LUMSDEN CUNLIFFE. (..s.)