Improvements in Hydraulic Air Compressors.
Year: 1896

page_text: Date of Application, 19th Feb., 1896-Accepted, 21st Mar., 1896
COMPLETE SPECIFICATION.
Improvements in Hydraulic Air Compressors.
I, CHARLES ARTHUR ALLISON, of 52 Chancery Lane, London, in the County
of Middlesex, Patent Agent, do hereby declare the nature of this invention
(which has been communicated to me from abroad by "The Berner-Mayer Company
(Incorporated)," of Cleveland, Ohio, United States of America), and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
The invention relates to that class of air-pumps in which water pressure is
utilized for operating the piston. In such pumps it is usually necessary to have a
nice adjustment and regulation of the parts. The inlet valve must be so constructed
and arranged as to admit the water at the proper time to give the piston its
forward or compression stroke at the end of which, this valve must be closed, the
water outlet valve opened and the water discharged from the cylinder during the
return or back stroke.
The objects of the invention are to construct a hydraulic air-pump in such a
manner as to simplify the valve mechanism and water connections and to insure
efficiency and it consists in the construction and arrangement of parts all as
hereinafter described and pointed out in the claims.
In the accompanying drawings,
Figure 1 is a vertical central section of the improved air-pump, showing the
sliding weight or piston in its lowest position within the cylinder and with the
water inlet-valve open to admit the water for actuating the piston. Figure 2 is a
similar section but showing the piston in its highest position or at the end of its
compression stroke and showing also the air relief-valve open, the water inlet-
valve closed and the water outlet-valve open or lifted from its seat for permitting
the water to flow out during the return of the piston to its former or normal
position.
Figure 3 is a horizontal section taken on the line 3, 3, of Figure 1, giving a plan
view of the seat for the water outlet-valve and of the surrounding port through
which the water flows to the discharge outlet, and in this figure, the stem of the
water inlet-valve is shown in section.
Figure 4 is a horizontal section taken on the line 4, 4, of Figure 1, showing the
water outlet-port at a lower point than in Figure 3, the discharge outlet appearing
in section as does also the stem of the water inlet-valve.
Figure 5, is a detached perspective view of the air relief-valve which is operated
by the piston near the end of its compression stroke when it becomes necessary to
open the water outlet-valve.
Figure 6 is a detached perspective view of the water outlet-valve showing its
form and the yoke by which it is connected to the stem of the water inlet-valve
and to a rod by which both valves are lifted so that the inlet-valve is brought to
its seat and the outlet-valve away from its seat.
Figure 7 is a separate or detached view of the weight or piston which is moved
within the cylinder and shows in connection therewith the water-inlet and the
water outlet-valves.
Figure 8, is a vertical sectional representation of an air-compressor embodying
the invention constructed according to a modification in which the air relief-valve
and the spring are both omitted. In this figure the air compressing piston is
shown in its lowest position, the water inlet-valve open, and the water outlet-valre

page_text: 1
closed. Figure 9, is a similar sectional representation of the same modification
omitting some of the parts at the top and showing the air compression piston in
its highest position, the water inlet-valve closed and the water outlet-valve open.
Figure 10, is a view of the water inlet and outlet valves and connecting tube
with a small piston shown also in Figures 8 and 9.
In these drawings A represents the pump-cylinder which may be of glass, metal
or any other suitable substance. This cylinder is covered at the top by a head B,
which for convenience of manufacture, is preferably formed in sections or parts a, b, c,
one above the other, with a dome B₁ at the top, as shown. The section a is
secured over the top of the cylinder A, and is provided with a chamber a¹ which
communicates with the interior of the cylinder. The chamber a¹ contains an air
relief-valve a' the form of which is best shown by Figure 5, and this relief-valve
rests upon a seat a so as to cover a port at which when open makes communication
between the chamber a¹ and the atmosphere.
A gasket or packing ring is preferably interposed at the juncture of the
sections a and b in order to insure an air-tight joint. The section b is provided
with an air inlet-port & closed at its inner end by a light valve 63 preferably of
rubber and this valve when drawn or lifted from its scat permits free ingress of
the air which passes through a communication & to the chamber a¹, and from
thence to the interior of the cylinder. A gasket el is shown as being placed on
the top of the section 6 over which there is a diaphragm e² having a collar c³ with
a central opening for permitting the compressed air to pass into a slitted rubber
discharge valve c which is secured over the collar c³. The flanged base of the
dome B' rests on the diaphragm and is secured along with it and the air
discharge valve, by the section c screwed to the top part of the section b as shown.
The dome B' is provided with an outlet to be connected with a tube or pipe
leading to a reservoir, not shown, for receiving the air when compressed.
A molded weight C preferably of lead, which also acts as the piston is placed
within the cylinder A, and has its lower end secured to a base or bottom piece D
by a screw threaded projecting tube or pipe d around which the lead is molded and
thus secured thereto. A packing d' is interposed between the weight C and its
base D, in order to close the clearance and make a water tight joint between the
piston and the cylinder. The tube d also extends upwardly within the weight
nearly to the top and contains a rod with a head or flange 3 at its top. This
rod is surrounded by a spring d', which seats on the base or bottom piece D as
shown in Figures 1 and 2.
The rod d³ passes through the base of the piston and is provided with a nut or
flange d which receives the screw threaded end of the stem e of the water inlet-
valve after such stem has been screwed through the yoke of the water outlet-
valve e, which seats over an outlet-port e made in the base casting E, of the
cylinder A.
This base casting is secured to the cylinder by a screw threaded collar f; and,
it is provided with a water inlet port f¹ communicating with some source from
which the water can be supplied under pressure. A chamber F, is formed in the
base casting beneath the bottom piece of the piston and the inlet port f¹ com-
municates with this chamber by a passage around the stem of the water inlet-valve.
The discharge valve e being located within this chamber over the port e prevents
the water from passing out of it until lifted from its seat when the water will be
free to emerge through an outlet pipe or passage f" from which it is discharged
or led away. The valve e' with its stem e is inserted through an opening in the
bottom of the casting E and when secured the opening is closed by a nut fas
shown in Figures 1 and 2.
Viewing the compressor with its parts in the position shown in Figure 1, it will
be observed that the weight or piston C, is in its lowest position within the
cylinder A, and that assuming the connections to be made for operating the
compressor the cylinder above the piston will be filled with air, the air inlet-valve b³
and the air outlet or discharge valve c', will both be closed while the relief valve a³

page_text: will be resting on its seat as shown. In such case the water.inlet-valve e will be
open and the water discharge or outlet valve, will be resting on its seat over
the water outlet port e as shown.
The operation of the pump begins by the inflow of water through the port f
in the direction indicated by the arrows. The water rises in the chamber F until
it reaches the bottom D of the piston C, when it will raise the piston and force it
up within the cylinder compressing the air in the space above it. As the air
begins to compress it will act against the air inlet-valve forcing it tightly to its
seat and finding no escape will pass within the air discharge valve c, and open the
slit through which it can pass into the dome 131 and to the reservoir. While the
piston is moving upward the air also acts against the top surface of the relief-
valve a³, so as to force it more tightly against its seat.
During the upward movement of the piston the rod d remains stationary until
the spring a contracts by reason of its meeting the upper head or flange of the
rod and the tendency will be left to lift the water outlet-valve e, but as the
lower portion of the cylinder is at this time filled with water under pressure
the spring d will contract to its limit without either closing the inlet valve e or
opening the outlet-valve e. When this point is reached the weight C strikes the
projections of the ait relief-valve a² which lifts it from its seat, and the escape of
air from the chamber al permits the piston to move rapidly up to the top of the
cylinder, while at the same time the spring d' expands and lifts the rod d so as to
close the water inlet valve e¹ and open the water outlet-valve e³. When the air relief
valve a² is opened to permit the air to escape from the chamber a¹ the back pressure
of the air in the dome B' will act to close the slit in the air discharge-valve c', and
prevent return of the air already compressed.
The water outlet-valve e being open and the water outlet-valve el being closed,
the act of compression ceases and the water recedes from the cylinder and passes
off through outlet f. The piston C moves down within the cylinder A, creating a
suction which acts to lift the air inlet-valve and open the air inlet port, by
which means the air space within the cylinder is filled. The pressure of the water
upon the water inlet-valve e' keeps it closed and holds the stem e together with the
rod d up until the base D of the weight C reaches the flange d on such rod, which
is thereby depressed and carries the water outlet-valve e to its seat, at the same
time opening the water inlet-valve e when the piston will again be moved up and
compress the air as before, and the operation can be repeated over and over until
the water pressure is shut off.
In the modification shown in Figures 8 and 9 the air relief valve a' and the
spring d' are omitted and the construction of the pump is to that extent simplified,
and in order to accomplish this result it has been found desirable to interpose a
small piston in the bottom of the casting E and connect the same with the water
outlet-valve by a tube or sleeve; in using such form of connection the inlet-valve
stem e is made to pass loosely through the yoke 2 of the water outlet-valve e
instead of being rigidly connected therewith, but it connects with the rod d'as
shown in Figures 1 and 2.
The water outlet-valve e is in the modification shown, secured to the upper end
of the tube or sleeve g, at the lower end of which the small water piston g' is made
fast and provided with a packing g². The piston g¹ operates for a short distance
along the wall of an aperture made in the casting E between the water
inlet-port and the water outlet-port e as shown in Figures 8 and 9. The
walled aperture g extends down to the bottom of the casting E so as to make an
opening through which the water inlet and outlet valves with their connections
may be inserted and secured. This aperture is closed by a cap and packing A',
while on the inside of the cap there is a projection or piece 4 having in its upper
surface a recess g³ which forms a seat for the water inlet-valve e¹ to support the
stem e and rod d when the valve is open and the piston C is operating.
In this construction and arrangement of the water inlet and outlet valves in
connection with the pump already described, the piston C operates as before.

page_text: But when the piston C is nearing the end of its up or compression stroke the flange
or head on the rod d will come against the bottom of the tube d and pull the
stem e of the water inlet valve el against its seat at the lower end of the sleeve g
and thereby close the water inlet port. When this port is closed the pressure of
the water in the aperture g' will cause the piston g' to rise and carry with it the
tube or sleeve a thereby lifting the water outlet-valve from its seat. The water
outlet-port being thus opened the cylinder A. will soon be emptied and during
the outflow of the water the small piston g' will be kept up by the pressure of the
water from below which will also keep the water inlet-valve closed until the
piston C has descended far enough to come against the top of the rod d' or its
head d.
When this point is reached the weight of the piston C will depress the rod d
and with it the stem e and water inlet-valve e'. During this period the nut or
flange will come against the top of the yoke e² of the water outlet-valve e³ and
carry this valve, its sleeve g and small piston g' down to their former position, so
that the water outlet-valve is closed and the water inlet-valve opened by the time
the piston C has reached its lowest point. The chamber F will then fill with
water as before and the operation of the pump will be continued so long as water
under pressure is admitted through the inlet-port.
It is obvious that variations in the way of modifications not shown and in
details not specifically pointed out, may be made without departing from either the
spirit or substance of the invention and it is not therefore confined to the exact
forms and arrangements shown and described.
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 a hydraulic air-compressor the combination of a cylinder provided with
air-inlet and outlet ports and valves, a weighted piston in said cylinder, water inlet
and outlet chambers, ports and valves, a water inlet channel making communication
between said chambers, and a stem connected with the water inlet valve and made
to pass through said inlet channel and have connections with the outlet valve and
with said piston substantially as set forth.
2. In a hydraulic air-compressor, the combination with an air-cylinder, of air
inlet and outlet ports and valves a weighted compressor piston having an aperture
therein closed at its top, a rod in said aperture adapted to be moved by said piston,
water inlet and outlet ports and valves, the water inlet valve being provided with
a stem passed through a water inlet channel of larger diameter and having
connections with the water outlet valve and with said rod, substantially as set
forth.
3. In a hydraulic air-compressor, the combination with an air-cylinder, of air-
inlet and outlet ports and valves, a weighted compressor-piston having therein an
aperture closed at its top, a rod having a head at its top within said aperture,
water-inlet and outlet ports and valves leading to and from a water space beneath
said piston, a stem connecting with said water inlet-valve and with said rod, said
stem being made to have connections with the water outlet valve substantially as
set forth.
4. In a hydraulic air-compressor, the combination with an air-cylinder, of air-
inlet and outlet ports, and valves, a weighted compressor-piston having therein an
aperture closed at its top a rod having a head at its top within said aperture, a
water chamber beneath said piston having an outlet-port for the water, a valve for
closing said port, a water inlet port leading to said chamber through said water
outlet-valve, a water inlet valve for closing the said inlet-port and having a stem
made to pass through said water outlet-valve and connect with said rod, arranged
to operate substantially as set forth.
5. In a hydraulic air-compressor the combination with an air-cylinder, of air-
inlet and outlet ports and valves a weighted compressor piston having therein an

page_text: aperture closed at its top, a rod within said aperture having a head at its top, a
spring in said aperture around said rod near its lower end, water-inlet and outlet-
ports and valves leading to and from a water space beneath said piston, a stem
connecting said water inlet-valve with said rod, said stem being made to pass through
said water outlet valve, arranged to operate substantially as set forth.
6. In a hydraulic air-compressor, the combination with an air-cylinder, of air-
inlet and outlet ports and valves, an air-relief port and valve, a weighted
compressor-piston having therein an aperture closed at its top, a rod within said
aperture having a head at its top, a spring in said aperture around said rod near
its lower end, water-inlet and outlet ports and valves leading to and from a water
space beneath said piston, a stem connecting said water inlet-valve rigidly
with said water outlet-valve and with said rod, arranged to operate substantially
as set forth.
7. In a hydraulic air-compressor the combination with an air-cylinder, of air-
inlet and outlet ports and valves, an air-relief port and valve, a compressor piston
having therein an aperture closed at its top a rod having a head at its top within
said aperture, a spring in said aperture beneath said piston, having an outlet port
for the water, a valve for closing said port, said valve being provided with a yoke,
a water inlet-port leading to said chamber through said water outlet-valve, a
water inlet-valve for closing said inlet-port, a stem connecting said inlet-valve
rigidly with the yoke of said outlet-valve and with said rod, arranged to operate,
substantially as set forth.
8. In a hydraulic air-compressor, the combination with an air-cylinder, of air-
inlet and outlet ports and valves, a compressor-piston C, having therein a tube d
forming an aperture closed at its top, a rod d² in said aperture, having a head d³
at its upper end, and a flange d' at its lower end, a water inlet-valve e', a water
outlet valve e having a yoke e, a stem for said inlet-valve el, made to pass through
the yoke of the inlet-valve e³, and connected with the flange d³ of the rod d²
constructed and arranged, substantially as described.
9. In a hydraulic air-compressor, the combination with an air-cylinder, of an air-
inlet, a valve 6s for opening and closing said inlet, an air outlet and a valve c
adapted to permit compressed air to be discharged therefrom, and to prevent its
return, an air relief-port a', and a valve a² having a projection extending into said
cylinder, a compressor-piston C, having therein an aperture closed at its top, a
rod din said aperture, having a head d³ at its top, a spring d around the lower
end of said rod, water inlet and outlet ports and valves leading to and from a water
space beneath said piston, a stem connecting the water inlet valve rigidly with the
water outlet valve and with said rod d2 arranged to operate substantially as set
forth.
the 10th day of February 1896.
ALLISON BROS.,
Agents for the Applicant.