Cylinder pump having an air sensor activated reversing valve

The present invention relates to an improved cylinder pump. The cylinder pump includes air hoists enabling the entire pump assembly to be lifted so that a container may be placed thereunder and thereafter the air hoists may be biased downwardly so that the follower plate of the pump mechanism will bear down on top of the liquid contained within the container. Thereafter, the air cylinder of the pump is activated and reciprocated up and down through the provision of a four port reversing valve activated through the use of air sensors to cause the pump to pump fluid out of the container while the downward bias of the air hoists keeps the follower plate in contact with the surface of the liquid within the container. By separating the air cylinder actuator for the pump mechanism from the four port reversing valve thereof, improved reliability and quietness are attained.

BACKGROUND OF THE INVENTION 
In the prior art, pumps are well known and are used in various environments 
to pump various fluids from one location to another as desired. Examples 
of prior art pumps are taught by U.S. Pat. Nos. 3,945,768 to Georgi and 
4,405,292 to Bixby Jr., et al as well as U.S. Pat. No. 4,477,232 to Mayer. 
Furthermore, pumps are made by the Alemite and Graco Company which include 
air hoists and a follower mechanism, however, these pumps are inferior to 
the teachings of the present invention as including an air motor head 
which combines a piston-cylinder with the control valves therefor in a 
single housing. This arrangement has been found by applicant to be 
troublesome and annoying in that the combined housing includes the outlet 
ports to atmosphere for the control valve and piston-cylinder and the 
control valve is quite noisy in conjunction with the annoying noises 
caused by the various ports. As such, a need has developed for a pump 
mechanism which separates the piston-cylinder from the control valve 
therefor to thereby reduce the noise levels in the vicinity of the pumping 
operation. Further in this regard, the specific mechanism built into the 
head of the prior art pump includes latches and springs to direct air 
internally thereof to control movements of the pistons in the cylinder. In 
operation, switching of the exhaust of air out of the various ports causes 
a snapping sound to occur which is extremely noisy and annoying. Thus, a 
need has developed for an improved pumping device which separates the 
control valve from the piston-cylinder so as to enable the reduction of 
annoying noises during the operation of the pump. 
SUMMARY OF THE INVENTION 
The present invention overcomes the deficiencies found in prior art pumps 
and provides a new and improved cylinder pump which comprises a vast 
improvement over prior art designs. The present invention includes the 
following inventive features: 
(a) In a first aspect, the inventive cylinder pump includes a pair of air 
hoists which are designed to enable the selective lifting of the entire 
pump assembly to enable the placement of a container of liquid thereunder 
with the further provision of the ability to bias the air hoist downwardly 
to thereby cause the pump follower to engage the surface of the liquid 
within the container with a force bias. 
(b) As inferred above, the pump assembly itself is mounted on a framework 
carried by the air hoists. The pump assembly includes an elongated 
cylindrical cylinder having a bottom inlet with the cylinder being mounted 
on a follower plate designed with a peripheral seal designed to ride in 
sealing engagement with the walls of the container, the fluid of which is 
to be pumped therefrom. 
(c) An elongated piston rod with a piston at its lower end is slidably 
received within the elongated cylinder with the piston including a check 
valve designed to allow fluid to fill the cylinder above the piston during 
a downward stroke of the piston and to close and allow fluid above the 
piston to be pumped from the cylinder and out a discharge opening during 
upward movements of the piston rod and piston. 
(d) The piston and rod are reciprocated up and down within the elongated 
cylinder by virtue of an air cylinder the movements of which are 
controlled by a four port reversing valve and air sensors. The air sensors 
comprise pilot devices which sense the position of the piston within the 
air cylinder and responsive to such sensing cause shifting of the four 
port reversing valve to result in reversal of the direction of movement of 
the piston within the air cylinder. It is important to note that the 
present invention separates, physically, the location of the four port 
reversing valve from the air cylinder housing to thereby enable the better 
control of the noises which naturally emanate from a four port reversing 
valve. In this regard, the vents on the four port reversing valve may be 
better muffled when it is contained in a separate housing not attached to 
the air cylinder housing. 
Accordingly, it is the first object of the invention to provide an improved 
cylinder pump. 
It is a further object of the invention to provide an improved cylinder 
pump having air hoists to lift the pump assembly and thereafter bias the 
follower plate thereof in engagement with a column of liquid contained 
within a container. 
It is a further object of the invention to provide such a pump with an air 
cylinder actuator for the pump portion thereof having a control valve 
therefor physically separated from the air cylinder housing. 
These and other objects, aspects and features of the present invention will 
be better understood from the following detailed description of the 
preferred embodiments when read in conjunction with the appended drawing 
figures.

SPECIFIC DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to FIG. 1, the inventive cylinder pump is generally 
designated by the reference numeral 10 and is seen to include a base 11 on 
which are mounted two elongated cylinders 13 each of which has slidably 
mounted therein a piston rod 15 carring a piston 17 having an outer 
periphery designed to be snuggly engaged with the internal surfaces of the 
cylinder 13. 
The piston rods 15 are seen to extend upwardly and into attachment with a 
frame structure 19 which includes a horizontal frame member 21 having 
vertical attachment members 23 each of which attaches a respective piston 
rod 15 and wherein the horizontal frame member 21 has attached thereto 
elongated guideposts 25 which are maintained in spaced relation by a 
guidepiece 27 and extend downwardly into attachment with a follower plate 
29 having a peripheral inflatable seal 31 mounted thereon for a purpose to 
be described in greater detail hereinafter. 
The guideplate 27 is rigidly mounted to the guidepost 25 by virtue of 
collars 33 and the guideplate also provides a support for the air cylinder 
35 which has contained therein a piston 37 having attached thereto 
elongated piston rod 39 having, at its distal end, a double piston head 
41. The piston head 41 is seen to reciprocate within an elongated cylinder 
43 which is mounted between the follower plate 29 and the guideplate 27. 
The piston head 41 is seen to be slidably received within the internal 
walls of the cylinder 43 and the piston head 41 includes check valve 
structure (not shown) which is operative to allow fluid therepast during 
the downward stroke of the piston head 41 and to close on the upward 
stroke of the piston head 41 to thereby enable the pumping of fluid 
entering the bottom inlet 45 of the cylinder 43 out the discharge port 47 
and to a point of desired use. 
With reference to FIGS. 1 and 2, movements of the piston 37 within the 
cylinder 35 are controlled by virtue of a directional control valve 49 
known to those skilled in the art as a four port reversing valve. The 
control valve 49 is controlled by air sensors 51,53 (FIG. 2) which sense 
the position of the piston 37 within the cylinder 35 and responsive 
thereto cause shifting movements of the control valve 49. 
With reference to FIG. 2, the control valve 49 includes a housing 55 in 
which a spool 57 is contained which spool includes passages 59,61,63 and 
65 therethrough. As seen in FIG. 2, the passages 59 and 61 are parallel to 
one another whereas the passages 63 and 65 cross one another. The housing 
55 includes a inlet port 67 connectible to a source of fluid pressure, an 
inlet-outlet port 69 substantially aligned with the inlet port 67, an 
outlet-inlet port 71 adjacent the inlet-outlet port 69 and an outlet port 
73 comprising a restrictive orifice. As should be understood from FIG. 2, 
when the spool 57 is in the position shown the port 69 is the outlet port 
conveying fluid pressure from the port 67 via the passageway 59 in the 
spool 57 through the port 69 and to the cylinder 35 port 32 to cause 
downward movements of the piston 37 and the downward movements of the 
piston 37 will cause air flow out the port 34 via the passageway 36 to the 
port 71 of the valve 49, through the passageway 61 and out the restricted 
orifice outlet port 73. If, on the other hand, the spool 57 is shifted in 
the left-hand direction, then fluid pressure at the inlet port 67 will be 
conveyed via the spool passage 65 to the port 71 now an outlet port to 
thereby convey fluid pressure to the port 34 of the cylinder 35 to thereby 
cause upward movements of the piston 37 therewithin to thereby cause fluid 
pressure to pass out the port 32 and via the passage 38 to the valve 49 
port 69 and via the spool passageway 63 to the restricted orifice outlet 
port 73. 
As should be understood by those skilled in the art, the lines 75 and 77 
are respective sensing lines which respectively connect with the air 
sensors 51,53 and which convey fluid pressure to the ends of the spool 57 
to cause it to move in one direction or another. For example, with 
reference to the air sensor 51, with the spool in the position shown in 
FIG. 2, air pressure at the line 67 will be conveyed via the spool passage 
59, the port 69 and the line 38 via the air sensor 51 to the port 32 to 
cause downward movements of the piston 37. Simultaneously, pressure in the 
line 38 is conveyed via the line 40 to the air sensor 53 but due to the 
pressure in the port 34 caused by downward movements of the piston 37, the 
sensor line 77 is kept disconnected from the line 40. When the piston 37 
has reached the bottom of its travel, the pressure at the port 34 is 
lessened to zero thereby causing a diaphragm valve contained within the 
air sensor 53 to relax allowing interconnection of the lines 40 and 77 to 
thereby cause pressure therein to be seen on the right-hand side of the 
spool 57 thereby shifting the spool 57 in the left-hand direction to 
thereby cause reversing of the direction of flow of fluids through the 
system. 
With the piston 37 in the downward position, and the valve spool 57 having 
been shifted leftward, fluid at the inlet port 67 will flow via the spool 
passageway 65 to the port 71 and line 36 through the air sensor 53 and to 
the port 34 to thereby cause the piston 37 to lift upwardly causing fluid 
pressure at the port 32 to pass through the air sensor 51, line 38 port 69 
passageway 63 and outlet port 73. 
Meanwhile, fluid pressure in the line 36 passes through the line 42 to the 
air sensor 51 but is prevented from fluidly connecting with the sensor 
lines 75 due to the diaphragm contained in the air sensor 51 which 
prevents such interconnection due to the pressure of fluid in the air 
sensor seen at the outlet port 32. When the piston 37 has reached its 
uppermost travel, pressure at the point 32 is reduced to zero thereby 
allowing the fluid pressure in the line 42 to pass by the diaphragm of the 
air sensor 51 and fluidly connect with the sensor line 75 to thereby cause 
right-hand movement of the spool 57 to thereby reverse the fluid flow 
paths. 
With reference to FIG. 3, the air sensor 53 is seen to include a housing 
81, a chamber 83, a diaphram 85 and a chamber 88. The housing 81 includes 
ports 87 and 89 and internal passageways 91 and 93 which terminate on 
opposed sides of the chamber 88 and which are prevented from communicating 
with one another due to the diaphragm 85 when there is a significant 
pressure within the chamber 83, but, which passageways 91,93 are allowed 
to communicate with one another through pressure in the lines themselves 
when pressure in the chamber 83 is reduced to zero. 
The air sensor 51 is identical in construction to the air sensor 53. In the 
view of FIG. 3, to place the air sensors in perspective, the port 87 is 
connected to the passageway 28 shown in FIG. 2, the port 89 is connected 
to the passageway 36 shown in FIG. 2, the passageway 93 is connected to 
the passageway 40 and the passageway 91 is connected to the sensing line 
77. As such, it should be understood that when the piston 37 is moving 
downwardly within the cylinder 35 and pressure is seen at the port 34 and 
line 28, that fluid passing through the chamber 83 and to the port 89 and 
outlet line 36 will cause the chamber 83 to become pressurized thereby 
causing downward bias on the diaphragm 85 to cause the diaphragm 85 to be 
bias against the outlets of the passageways 93 and 91 thereby preventing 
communications therebetween. On the other hand, when the piston 37 has 
completed its downward travel and the pressure at the port 34 and thereby 
in the chamber 83 has been reduced to zero, the downward bias on the 
diaphragm 85 is eliminated and pressure in the passageway 40 and the 
passageway 93 will cause upward movement of the diaphram 85 so that such 
fluid pressure may enter the passageway 91 and sensing line 77 to cause 
left-hand movement of the spool 57. From this, the operation of the air 
sensor 51 should be clearly understood. 
It is an important aspect of the present invention that the four port 
reversing valve 49 is completely separate and apart from the cylinder 35 
and in this way the valve 49 may be provided with speed reducing outlet 
structure 73 with muffler 74 to control speed of exhaust and noise and 
other noises which occur in prior art constructions when the air cylinder 
has incorporated therewith the reversing valve structure. Furthermore, the 
use of air sensors such as those designated by the reference numeral 51 
and 53 instead of mechanical springs, latches and levers causes 
significant reduction in the noises which occur during the operation of 
the prior art valve structure. 
With reference back to FIG. 1, it is seen that each air hoist includes two 
ports 14 and 16 which control upward and downward movements of the pistons 
17 therein and thereby upward and downward movements of the frame 19 and 
attached pump mechanism. 
In the operation of the present invention, when it is desired to pump fluid 
from a cylindrical container having an inside diameter equal to the 
outside diameter of the follower plate 29, the ports 14 are pressurized 
with fluid to thereby cause the lifting of the entire pump assembly, 
whereupon the cylindrical container may be placed in alignment underneath 
the follower plate 29 whereupon fluid pressure may be applied at the ports 
16 to lower the follower plate 29 into the cylindrical container (not 
shown) whereupon the peripheral seal 31 of the follower 29 will sealingly 
engage the inner walls of the cylindrical container causing the inlet 45 
to be fluidly connected with the fluid in the cylindrical container. 
With the bias caused by air pressure at the ports 16 being maintained, the 
piston 37 may be activated in up and down movements responsive to control 
as explained hereinabove with reference to FIGS. 2 and 3 to thereby cause 
fluid to be pumped in the inlet 45 past the piston 41 via the check valve 
(not shown) and out the discharge point 47 to a point of use. During these 
pumping operations, as the level of fluid in the cylindrical container 
lowers, the air pressure at the ports 16 will cause lowering of the 
pistons 17 and thereby lowering of the follower plate 29 into the 
container to maintain contact of the underside of the follower plate with 
the surface of fluid within the cylindrical container. When the 
cylindrical container has been exhausted, fluid pressure may be placed on 
the inlet ports 14 to raise the pump assembly to a position where the 
cylindrical container may be removed from the base 11 and may be replaced 
with a further cylindrical container. 
Accordingly, an invention has been described in terms of a preferred 
embodiment thereof which fulfills each and every one of the objects as set 
forth hereinabove and provides a new and improved cylinder pump assembly 
which is much quieter in operation than prior art designs and which has 
greater reliability in operation. Of course, various changes, 
modifications and alterations to teachings of the present invention may be 
contemplated by those skilled in the art without departing from the 
intended spirit and scope of the present invention. Accordingly, it is 
intended that the present invention only be limited by the terms of the 
appended claims.