Pneumatic pump

A submersible pump casing is supported for limited vertical movement. Buoyancy of the casing changes according to the amount of water in the chamber. When pressurized air continuously supplied to the chamber has discharged most of the water, the casing rises, opening a vent and allowing an inrush of water through a large inlet at the bottom of the casing. A float closes the vent and the cycle repeats. The vent is a simple flapper, and the vent itself is large whereby the filling is quickly accomplished. The flapper is cracked to allow quick opening by a simple push rod and bar mechanism.

FIELD OF INVENTION 
This invention relates to a submersible water pump that is operated by 
compressed air. 
BACKGROUND OF THE INVENTION 
The present invention is intended to satisfy the demand for a small rugged 
water pump that can be teamed up with a wind machine and an air compressor 
driven by the machine. The primary object of this invention is to provide 
a water pump of this character that utilizes simple and reliable 
mechanisms for performing valve functions in a positive displacement pump 
organization. 
SUMMARY OF THE INVENTION 
In order to achieve this objective, I provide a submersible pump casing 
that is supported for limited vertical movement. Compressed air is 
continuously supplied to the top of the pump chamber, causing water to be 
discharged through outlet means at the bottom of the chamber. Internal 
pressure maintains a large inlet valve closed. As water is discharged, a 
point is reached when the buoyancy of the casing is neutral. By 
controlling the weight and size of the casing, the neutral buoyancy 
condition occurs just before the casing is emptied. Further displacement 
of water causes positive buoyancy and rapid rise of the casing. As the 
casing approaches its upward limit, abutment means operate a large vent 
whereupon internal pressure is released. The inlet valve opens in response 
to release of internal pressure and water rushes in nearly to fill the 
pump chamber before the increased weight of the case overcomes inertia. A 
float then closes off the large vent opening and the compressed air 
pressurizes the chamber as the inlet valve settles to close. The cycle 
then repeats. 
A series of downwardly projecting outlet tubes conveniently form a cage for 
the ball closure of the inlet at the lower end and for the float at the 
upper end. Both the inlet valve and the vent valve are very large in order 
to provide quick and nearly complete filling. The vent valve is designed 
as a simple flapper type, covering both a main vent orifice and a 
secondary small orifice. The small orifice is opened by small force so 
that the closing force of the compressed air is overcome by a cracking 
technique.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
The following detailed description is of the best presently contemplated 
modes of carrying out the invention. This description is not to be taken 
in a limiting sense, but is made merely for purposes of illustrating the 
general principles of the invention, since the scope of the invention is 
best defined by the appended claims. Structural and operational 
characteristics attributed to forms of the invention first described, 
shall also be attributed to forms later described, unless such 
characteristics are obviously inapplicable or unless specific exception is 
made. 
The pneumatic pump 8 shown in FIG. 1 comprises a pump casing 10 made of a 
length of cylindrical plastic or metal tubing approximately four to six 
inches in diameter, and top and bottom end pieces or caps 12 and 14 (FIG. 
2) fitted and secured to the ends of the casing 10. The pump 8 is 
supported in a vertical orientation by the aid of a vent pipe 16. The vent 
pipe is threadedly attached to the center of the end cap 12 in registry 
with a through central vent opening 18 in the cap 12. The pipe 16 projects 
into a tubular guide 20, in turn supported by a standard 22 (FIG. 1). 
A collar 24 (FIGS. 2 and 4) threadedly attached to the lower end of the 
guide 20 cooperates with a stop ring 26 on the vent pipe 16 to limit 
downward movement of the pipe 16 and, hence, the pump 8. Engagement of the 
stop ring 26 with the lower end of the guide 20 limits upward movement. 
The range of movement is about an inch or two. Ambient water enters the 
casing 10 through a large diameter opening 28 (FIG. 4) in the lower end 
cap 14, and is trapped in by a ball 30 that has a specific gravity 
slightly greater than water. The ball 30 cooperates with a seat 32 on the 
inside of the cap 14. Ambient water will enter the pump chamber if the 
vent 18 is open. The vent 18 is opened and closed by a resilient flapper 
34 attached to the inside surface of the upper cap 12 as by the aid of 
screws 36. The resilience of the flapper 34 normally causes the flapper 34 
to assume a position flat across the vent opening 18 as shown in FIG. 2. 
The flapper 34 is pushed downwardly and away from the vent opening by the 
aid of a push rod 38 that operates when the casing 10 arrives at its upper 
position of FIG. 4. 
The push rod 38 extends through the bottom of an upwardly opening threaded 
recess 40 and is guided for vertical movement therein by a hollow cap 42. 
A compression spring 44 projects the push rod 38 to an upper position 
(FIG. 2) determined by engagement of a stop collar 46 with the inside of 
the cap 42. When the push rod 38 is projected upwardly by the spring 44, 
its lower end is retracted within a recess 48 located on the inside of the 
cap 12. The recess 48 is joined to the vent opening 18 by the aid of a 
slot 50 (see also FIG. 3). The recess 48 is closed by the very distal 
portion of the flapper 34. The lower end of the push rod 38 carries a bar 
52 that extends through the slot 50 and into the region of the main vent 
18. The undersurface of the bar 52 is curved so that as the push rod 38 
first operates, the edge of the flapper 34 is engaged by the end of the 
push rod 38. Portions of the flapper 34 progressively engage the more 
central regions of the flapper 34 as relative movement of the push rod 38 
progresses. Thus, the flapper 34 is cracked for initial venting through 
the auxiliary opening 48 whereby pressure on opposite sides of the flapper 
34 is equalized. Thereupon, full opening of the flapper 34 is readily 
achieved. 
As water nearly fills the casing 10, a relatively large float 54 moves 
upwardly to engage the flapper 34 and the stopped push rod 38, the weight 
of the water initiating downward movement of the casing 10 and retraction 
of the push rod 38. 
The float 54 is guided for limited vertical movement near the top of the 
casing 10 by the aid of four outlet tubes 56 (see also FIG. 3) that 
project downwardly from the upper cap 12 nearly to the level of the lower 
cap 14 (FIG. 2). Cross bars 58 laterally brace the outlet tubes 56 and 
limit downward movement of the float 54 away from the flapper 34. 
The tubes 56 register at their upper ends with an annular collection 
channel 60 and an outlet conduit 62, at least portions of which are 
flexible to allow for the reciprocating movement of the casing to which 
the conduit 62 is attached. 
The weight of the casing, increased by the volume of water admitted into 
the casing, assist the action of the float 54 to cause the casing to drop 
and the flapper 34 to close. The ball 30 at the bottom of the casing 10 
settles into closed position. Compressed air, such as provided from a 
windmill operated compressor, is continuously admitted into the casing 10 
via a conduit 64 that projects through the upper cap 12 and through the 
annular collection channel 60. As pressure builds, the flapper 34 firmly 
seats and water is forced into the outlet tubes 56, collection channel 60 
and outlet conduit 62. A check valve 66, if desired, prevents reverse flow 
during that portion of the cycle when water enters the casing 10. 
When much of the water in the chamber has been pumped out, the buoyancy of 
the casing 10 with associated equipment becomes neutral. This point is 
desirably achieved when the water level is slightly above the lower ends 
of the discharge tubes 56. Further removal of water under the influence of 
air pressure causes buoyancy rather rapidly to lift the casing 10 upwardly 
so that the push rod 38 engages the collar 24. The flapper valve is 
cracked open thereby, and readily opened to the full extent. Full opening 
of the vent 18 allows a heavy inrush of water and a repeat of the cycle. 
The ball 30 is caged by the lower ends of the discharge tubes 56. Bars 68 
(FIG. 2) limit upward movement of the ball 30. 
The lift obtained by the pump depends upon the pressure of air supplied. 
Lift is increased by using compressed air to lighten the column in the 
discharge conduit. This is achieved by a bypass conduit 70 (FIG. 1) 
controlled by a valve 72 that connects the air line 64 to the outlet 
conduit 62. 
DESCRIPTION OF ALTERNATIVE EMBODIMENT 
In the form of the invention shown in FIG. 5, a pump casing 80 is closed by 
end caps 82 and 84. A vent pipe 86 is accommodated in a guide 88 suspended 
from a float 90. For shallow pond operation, the diameter of the casing 80 
may be increased, thus to minimize its vertical dimension, yet to achieve 
reasonable displacement per cycle.