Year: 1897

page_text: I, CAPTAIN CECIL CLEMENT LONGRIDGE, Engineer, of 15-16, George Street, Mansion
House, in the City of London, do hereby declare the nature of this invention to be
as follows:-
:-
My invention relates to air pumps for steam engines, and its object is to pro-
duce an effective and economical air pump of the double acting type in which
the flow of water from the condenser to the pump is practically continuous. By
this continuous flow I am enabled to apply a comparatively high speed double acting
pump to jet condensers as well as to surface condensers.
My invention consists in a double acting pump of special construction, and in one
modification I entirely dispense with the so called suction or foot valve, and I cause
the pump piston to over-run a port or ports placed in the middle of the cylinder or
near the middle of the cylinder. The water and other contents of the condenser are
admitted to the air pump through this central port, uncovered by the travel of the
piston. The piston thus acts in conjunction with the ports in the cylinder in such
manner as to dispense with the foot valve. Sometimes, however, use in conjunc-
tion with the central port a foot valve, and sometimes I place the port nearer one
end of the cylinder than the other. In this latter case I so devise my passages as to
use one side of the piston for air pump with but little water, and the other side
practically for discharging water. When I use a foot valve I prefer to arrange it.
with a dash pot for air cushioning, and I also provide means for inspecting the action
of the discharge valves by arranging small glass covered apertures in an end plate
or cover plate, and sometimes an internal incandescent lamp.
In carrying my invention into effect according to one modification I construct a
horizontal air pump with ports placed in the centre of the cylinder, which ports are
preferably of elongated configuration, providing a gradual opening as the piston
uncovers them. These ports communicate with the condenser. In this cylinder I
place a piston having preferably conical ends. A piston rod passes through a stuffing
gland at one end to actuate this piston, and cylinder covers are formed carrying suit-
able lift valves for discharging water and air. The cylinder covers are preferably of
conical configuration, to allow of minimum clearance between the piston and the
covers. The air and water flow continuously into the cylinder except when the piston
may partially or entirely close the ports in passing over them, and are discharged
through the valves at one or other end of the pump alternately. The water and air
are discharged through the valve into a chamber at each end from which they flow
away through suitable openings which may be at the bottom of the chamber if it be
desired to keep the discharge free, or in the upper part if it be desired to drown the
valves. These chambers I cover with suitable plates, which may be of glass, but I
prefer ordinary metallic covers provided with one or more suitable apertures having
fitted in the aperture or apertures a small glass plate backed up by packing. By
means of glass plates I am enabled to inspect the action of the valves while dis-
charging liquid and gaseous contents into chamber. Sometimes I place within the

page_text: chamber an incandescent electric lamp suitably protected, also to allow of observa-
tion.
In another modification of my invention I arrange a vertical pump, and form the
ports towards the bottom of the piston stroke. I preferably arrange here also a
conical piston. The upper part above the piston serves practically almost entirely
for extracting the air, and the lower part serves as a water pump. The water
accumulates below the piston, and is forced through the lower cover valves. At the
termination of the down stroke the air finds its way above the piston and is forced
through the upper valves with a small quantity of water which may have mixed
with it.
My invention may be modified in various ways-provided the double acting
principle in combination with port or ports be adhered to.
Dated this 4th day of November 1897.
MARKS & CLERK,
Agents for the Applicant.
I, CECIL CLEMENT LONGRIDGE, Engineer, of 15-16, George Street, Mansion House,
in the City of London, 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 :-
My invention relates to air pumps for steam engines, and its object is to produce
an effective and economical air pump of the double acting type in which the flow of
water from the condenser to the pump is practically continuous. By this continuous
flow I am enabled to apply a comparatively high speed double acting pump to jet
condensers as well as to surface condensers.
My invention consists in a double acting pump of special construction, and in one
modification I entirely dispense with the so-called suction or foot valve, and I cause
the pump piston to over-run a port or ports placed in the middle of the cylinder or
near the middle of the cylinder. The water and other contents of the condenser are
admitted to the air pump through this central port, uncovered by the travel of the
piston. The piston thus acts in conjunction with the ports in the cylinder in such a
manner as to dispense with the foot valve. Sometimes I place the port nearer one
end of the cylinder than the other. In this latter case I so devise my passages as to
use one side of the piston for air pump with but little water, and the other side
practically for discharging water. If desired I provide means for inspecting the
action of the discharge valves by arranging small glass covered apertures in an end
plate or cover plate, and sometimes an internal incandescent lamp.
The four accompanying sheets of drawings illustrate my invention as applied to both
horizontal and vertical air pumps.
Figure 1 (Sheet 1) is a longitudinal section of a horizontal pump showing part of
the condenser.
Figure 2 (Sheet 2) is a vertical longitudinal section of one half of a similar horizontal
pump but with provision for flooding the valves, and
Figure 3 are half cross sections on a b and c d Figure 2.
Figure 4 (Sheet 3) illustrates in section one form of vertical pump, and
Figure 5 is a half sectional plan of Figure 4 with the section taken through the
line e f and piston left out.
Figure 6 (Sheet 4) is a sectional elevation of a further modification illustrating a
vertical pump.

page_text: In carrying my invention into effect according to one modification as illustrated in
Figure 1 of the drawings, I construct a horizontal air pump A with a port B, or ports,
placed in the centre of the cylinder, which ports are preferably of elongated
configuration providing a gradual opening as the piston uncovers them. These ports
communicate directly with the condenser C, the junction pipe of the same being
shown. Within the cylinder works a piston D which is preferably provided with
conical ends, and to which is connected a piston rod passing through a stuffing
gland E, cylinder covers being provided carrying suitable lift valves F for discharging
water and air. The cylinder covers are preferably of conical configuration to allow of
minimum clearance between the piston and the covers. The air and water from the
condenser C flow continuously into the cylinder except at that part of the piston's
stroke where the piston partially or entirely closes the ports in passing over them, the
air and water being discharged through the lift valves F at one or other end of the
pump cylinder alternately. After passing through the valves the water and air are
discharged into a chamber G at each end of the cylinder, the water flowing away
through suitable openings K which may be arranged at the bottom of the chambers
and the air passing through an overhead valve or valves I. The openings from the
chamber G may lead by suitable pipes to the atmosphere or if the water is to be forced
to a higher level than the pump, these openings may communicate with suitable air
vessels to regulate the flow of the water. I cover the discharge chambers G with
suitable plates J which may be of thick glass in suitable frames. By means of the
glass plates I an enabled to inspect the action of the valves F while discharging
liquid or gaseous contents into the chambers G. I sometimes place within the
chamber G an incandescent electric lamp, suitably protected to further facilitate
observation of the interior of the chamber. Generally however I prefer the
ordinary metal covers.
Figures 2 and 3 illustrate a modified form of air pump in which the water
after passing through the valves is trapped, the valves being thus flooded or
drowned, and in these figures B indicates the ports in the middle of the cylinder,
C the condenser, F the discharge valves, G the discharge chambers, and K the outlet.
Air and water from the condenser are forced through the valves F as before, but as
the openings in the discharge chambers are in the upper part of such chambers the
valves are flooded or drowned before the water can flow away. It is desirable in this
form of pump that the cover plates of the discharge chambers be made of metal
sufficiently strong to withstand the water pressure induced, and to meet this the
inspection apertures in the cover plates may be fitted with very thick glass panels.
At Figures 4 and 5 I illustrate one form of vertical pump.
The port or ports on the side of the pump cylinder may be arranged in the middle
as in the constructions previously described, or above or below the middle as may be
found desirable. It will generally be preferable to place the port in the middle of
the cylinder. In this pump also I prefer to use a piston conical on the under side,
providing this piston with an air passage M, passing from the conical hollow part
thereof to the circumference. When the piston is at the bottom of its stroke any
air which may have been trapped on the underside will escape through the passage M
into the discharge chamber G and through the valves F. Water is discharged at
both ends in nearly equal quantities. The valves F in this pump are always visible
and there are no inside fastenings liable to get loose or to cause damage. The
vertical height of the port or opening should not be great unless the speed of the
pump be high as otherwise too large a proportion of water lifted by the piston will
flow back into the condenser on the up-stroke.
In the sectional elevation of a pump shown in Figure 6 it will be seen that
the arrangement is similar to the form described with reference to Figures 4 and 5,
but the disposition of the bottom discharge valves is modified and the top and bottom
discharge chambers with their outlet pipes are arranged in more compact form as may
be required for special services. In this figure similar letters indicate similar parts
to those herein before described with reference to Figures 4 and 5.

page_text: My invention may be modified in various ways provided the double acting principle
and combination with a port or ports be adhered to.
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. In an air pump the provision of a port or ports in the side of the cylinder or
pump valve which port or ports communicate with the condenser and through which
water and air are drawn on both up and down strokes of the piston, said water and air
being discharged through suitable valves in the cylinder covers alternately at one or
other end of the cylinder substantially as herein before described.
2. The improved double acting air pump in which a port or ports is or are provided
at or about the centre of the pump cylinder, said port or ports serving to draw air and
water from the condenser to be discharged through suitable valves in the cylinder
covers and having chambers on the exterior of the valves which permit of the flooding
or drowning of the valves substantially as herein before described and illustrated in
Figures and 3 of the accompanying drawing.
3. In an air pump as specified in the previous claims providing on the end plate or
cover plate of the discharge chambers means for easy inspection of the interior valves
substantially as herein before described and illustrated.
4. The improved horizontal air pump hereinbefore described and illustrated in
Figures 1, 2 and 3 of the accompanying drawings.
5. The improved vertical air pump herein before described and illustrated in
Figures 4 and 5 and 6 of the accompanying drawings.
Dated this 22nd day of Anonst. 1898.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.