Improvements in Compressed Air Water Pumps or Elevators.
Year: 1899

page_text: Date of Application, 1st June, 1839 -Accepted, 29th July, 1899
COMPLETE SPECIFICATION.
Improvements in Compressed Air Water Pumps or Elevators.
I, MARCUS LAFAYETTE MITCHELL, a Citizen of the United States of America,
residing at 1220, Armstrong Avenue, in the City of St. Louis, in the State of
Missouri, Mechanical Engineer, 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 that class of pumps in which the water is first allowed'
to enter a suitable chamber through a valved inlet and then is forced out by the
admission of compressed air to said chamber.
My pump is especially adapted
to be used with two chambers so that the water is forced out of one while it is
entering the other, thus giving a continuous, or practically continuous, flow.
Many features of my invention, however, are applicable to pumps having but a
single chamber. l'umps of this class are usually submerged in the water so that
the water enters them by gravity.
As far as I am aware, all double-chambered pumps of the class above referred
to, which have been previously constructed, are either provided with only one
primary valve, or, where two primary valves are used, they are connected
together so as to act simultaneously. The objection to these two constructions,
which are substantially the same in effect, is that unless the water enters one
chamber at exactly the same rate that it is discharged from the other, there
will be a waste of air owing to its being allowed to escape through the discharge
pipe or to its being allowed to enter an incompletely filled chamber. One of the
principal objects of my invention is to so construct a. double-chambered pump
that the air supply will not be shifted from one chamber to the other until one
is emptied and the other is filled irrespective of whether or not the water enters
the pump at the same rate as it is discharged.
In pumps of the class referred to above, there is necessarily some space
between the water in the chamber and the main valve controlling the admission
of compressed air to the chamber. This space will be filled with air at or
only slightly above the atmospheric pressure.
When air under a high pressure
is to be admitted to this space, it causes a jar or hammering effect which is very
injurious to the mechanism of the pump. One object of my invention is to
raise the pressure in this space to substantially the working pressure before the
main air, port, is opened and thus to obviate this objection.
My invention consists in part in providing a double-chambered pump with two
primary valves, one for each chamber, and means for operating said primary
valves independently of each other by the rise and fall of the liquid in their
respective chambers, whereby the air-supply is not shifted from one chamber
to the other until one chamber is emptied and the other filled.
My invention also consists in providing the main valve with an auxiliary
port through which the air is admitted to the chamber to raise the air in the
same to practically the working pressure before the main port is opened.
My invention also consists in so arranging the main valve that the admission
of air can be cut off from one chamber before the exhaust is cut off from the

page_text: other chamber, so as to prevent waste of air and also to allow the said latter
chamber to be completely filled with water before the compressed air is admitted
to it.
My invention also consists in various other novel features and details of con-
struction, all of which will be described in the following Specification and
pointed out in the claims affixed hereto.
In the accompanying drawings which illustrate one form of pump made in
accordance with my invention, Fig. 1 is a vertical longitudinal central section;
Fig. 2 is an enlarged view of a portion of the valve mechanism shown in Fig. 1;
Fig. 3 is an enlarged view of the main valve shown in Fig. 2 but in a different
position Fig. 4 is a section on the line 4-4 of Fig. 2; Fig. 5 is a top plan
view of one of the parts shown in Figs. 2 and 4; Fig. 6 is a section on the
line 66 of Fig. 7; Fig. 7 is a top plan view of one of the discharge valve
casings Fig. 8 is a top plan view of one of the plates carrying the discharge
valves; Fig. 9 is a vertical cross section of one of the inlet valve casings;
Fig. 10 is a section on the line 10-10 of Fig. 1; Fig. 11 is an enlarged section
on the line 11-11 of Fig. 2; Fig. 12 is a bottom plan view of one of the inlet
valves; Fig. 13 is a section on the line 13-13 of Fig. 14; Fig. 14 is
a section on the line 14-14 of Fig. 11; Fig. 15 is a section
on the line 15-15 of Fig. 14; Fig. 16 is an elevation of the controlling valve
mechanism; Fig. 17 is a view showing some of the pipe connections; Fig. 18
(Sheet 4) is a top plan view of one of the valves shown in Fig. 16; Fig. 19 is
à section of a main valve for a pump having but one chamber; Figs. 20 and 21
are an enlarged section and top view respectively of a detail; and Fig. 22 is a
section of a primary valve for a pump having one chamber.
Like marks of reference refer to similar parts in the several views of the
drawings. 20 represents a cylinder which is divided into two chambers, 21 and 22,
by a partition 23. Each of the chambers 21 and 22 is provided with inlet
openings 24. Secured around the inlet openings 24 of each of the chambers, is
an inlet valve casing 25, shown in detail in Fig. 9.
Secured to the bottom
of the casing 25 is a plate 26, which carries the inlet valves 27. Each of the
valves 27 consists of a suitable metal disc 28 which is adapted to fit tightly in a
suitable opening in the plate 26 and is provided with openings 30. Secured in
the centre of the disc 28 is a rod 31, at the upper end of which is a head 32.
Sliding on the rod 31 is a disc 33 of rubber, or other suitable material, which is
adapted to close the openings 30. The head 32 limits the upward movement
of the disc 33. I prefer to use a number of these valves 27 in place of one
large valve, as the necessary amount of water can thus be admitted with less
movement of the valve, so that the valve acts more quickly and also causes
less jar in seating.
Extending upward from near the bottom of each of the chambers 21 and 22
is a pipe 35 (Fig. 1) which communicates with a discharge valve casing 36.
Contained in the discharge valve casing 36 is a plate 37 which carries a number
of discharge valves 38. The discharge valves 38 are constructed like the inlet
valves 27 previously described, and hence it is not necessary to describe their
construction in detail. I use a number of them for the reasons given in con-
nection with the valves 27. Leading from each of the discharge valve casings 36
is a pipe 39. The two pipes 39 may be connected to a common pipe 40, which is
then led to the point where it is desired to discharge the water.
Secured to the cylinder 20 is a casting 42 which is provided with two ports 43,
one of which communicates with each of the chambers 21 and 22 and alternately
serves as a supply and a discharge port for the compressed air. The casting 42
is also provided with an exhaust port 44 which is alternately connected first with
one and then the other of the two ports 43. The casting 42 has also formed
in it two grooves 45 (Fig. 5) for the reception of air pipes to be hereinafter
described. Secured to the casting 42 is a main valve casing 46 (Figs. 1, 2, 4,
16) and between the said parts is held a valve plate 47. Sliding in the valve

page_text: casing 46 is a piston 48. The central portion of the piston 48 is composed of
two webs 49 (Fig. 4), which webs have formed in their under edges recesses 41
for the reception of a slide valve 50 which controls the ports 43 and 44 which are
continued upwardly through the valve plate 47. The recesses 41 are of such a
length that the valve 50 will have some play and hence will not have as much
movement as the piston 48. Each end of the valve casing 46 communicates
by way of an auxiliary port or by-pass 51 with one of the ports 43, and in each
of the auxiliary ports 51 is placed a valve 52, preferably in the form of a small
rubber ball which seats upwardly and closes the contracted passage 53 which
connects the ends of the casing with the ports 51.
The slide valve 50 should be formed as shown in Fig. 3, so that it will close
the port 43 which has been in communication with the live air, before the other
port 43 is cut off from the exhaust. This is best done, as is shown in Fig. 3.
by having the opening 54 in the slide valve 50 of such length that when one of
the ports 43 is closed, an opening 55 will be left connecting the other port 43
with the exhaust port 44. Compressed air is admitted to the central portion of
the valve casing 46 through an opening 56 shown in Figs. 2 and 4. This opening
is connected with a suitable supply pipe 56 which leads either directly or
indirectly to the air compresser or reservoir for furnishing the compressed air.
The piston 48 should be of such a length that when it is in its central
position, as shown in Fig. 2, it will cover both the contracted passages 53 leading
to the ports 51. I prefer to line the ends of the valve casing 46 with cylinders 57
of bronze, brass or other suitable material which is not easily affected by water.
The ends of the valve casing 46 are closed by heads 58 which may be held in
position by cross-bars 59 and bolts 60 (Figs. 2 and 16), or any other suitable
means.
Formed in each of the ports 43, preferably some distance above the top of the
cylinder 20, are valve seats 62 (Figs. 1 and 2). 63, (Fig. 1) are conical valves
of rubber or other suitable material, which are adapted to seat against the valve
seats 62. Each of these valves 63 is carried by a float 64, preferably made of
hollow metal. The floats 64 are guided in their upward and downward move-
ment by suitable rods 65. The rods 65 should extend to near the bottom of the
cylinder 20 so as to allow the valves 63 to be at such a distance from their
seats, that there will be no danger of the out-going air seating them when the
air is exhausted. The object of the valves 63 is to prevent the water from
passing up through one of the ports 43 into the exhaust pipe in case the chamber
connected with the exhaust should become filled before the other chamber was
emptied.
Secured to the cylinder 20 are two primary valves 67, one of which com-
municates with the chamber 21 and the other with chamber 22. Each of these
valves 67 consists of a box or chest 68 (Figs. 2, 11, 14), from which projects a
suitable cylinder 69. Leading from the cylinder 69 of the valve 667, which is
in communication with the chamber 21, is a pipe 70 (see also Figs. 1, 4 and 16),
which communicates with the opposite end of the main valve chamber 46; and
leading from the cylinder 69 of the other valve 67 to the other end of the main
valve chamber 46 is a similar pipe 71. The pipes 70 and 71 lie in the
grooves 45 in the plate 42 (Figs. 4 and 5). In each of the cylinders 69 is a
piston 72 which has formed in it two reduced portions 73 (Figs. 2 and 11).. In
each of the evlinders 69, at the outer side of the pipes 70 and 71 respectively,
is formed an exhaust port 74, and at the inner side of said pipes, a supply
port 75.
Each of these ports 74 and 75 is adapted to be alternately connected
with one of the pipes 70 or 71 by the movement of the piston 72. 76 (Figs. 16,
17. 18) is an air supply pipe having two lateral branches which communicate
with the ports 75. The exhaust ports 74 are preferably connected with an
exhaust pipe 76". Connecting the outer end of the cylinder 69 with the box
or chest GS is a suitable port 77 (Fig. 2). The object of this port 77 is to
balance the piston 72, so that the pressure from the chambers 21 and 22 will

page_text: not affect the movement of said piston. The end of each of the cylinders 69
is preferably supplied with a screw-plug 78 to admit of the removal of the
piston 72; and the box or casing 68 is also preferably supplied with a screw-
plug 79 to give access to the interior thereof. Each of the pistons 72 is connected
by means of a link 80 with one end of a bell-crank lever 81 (Figs. 1, 2, 11, 14),
which projects upwardly into the interior of the box 68. The bell-crank
lever 81 is pivoted, by means of a pin 82 (Figs. 14 and 15), between two down-
wardly projecting arms 83 carried by the box 68. The lower end of the bell-
crank lever 81 is provided with two studs or pins, 84 and 85 (Fig. 13). The
pin 84 is adapted to work in a slot 86 formed in the upper end of a rod 87,
the lower end of which is pivoted to a bar 88 (Fig. 1), one end of which is
pivoted to an upright 89 and the other of which is attached to a weight 90.
The
stud or pin 85 is adapted to come in contact with a rod 91, one end of which
turns loosely on the hub 82 of the bell-crank lever 81, and the other end of which
is attached to a float 93. The weights 90 are in the form of floats but have
only sufficient buoyancy to sustain their own weight so as not to counteract the
effect of the floats 93. Depending from the top of the cylinder 20 are two
stops 94 which limit the downward movement of the floats 93, and two similar
stops 95 projecting upwardly from the bottom of the cylinder 20 limit the
upward movement of the weights 90. In order to economize space, I provide
domes 100, into which the Hoats 93 project when in their highest position.
These domes 100 are preferably formed integral with the lower parts of the dis-
charge valve casings. 36. By the use of the domes 100 the chambers 21 and 22
are allowed to become completely filled with water so that no air is wasted in
filling an air space with air at pumping pressure. In order to allow for the
escape of the air from the domes 100, after they have become water sealed from
the discharge ports, I provide them with valves 101 shown in detail in Fig. 10.
Each of the valves 101 consists of a lower or main part 102, and an upper
part or screw-cap 103. In the cap 103 are formed a number of openings 104
arranged around a central opening in which is secured a rod 105 provided with
a head 106. Sliding on the rod 105 is a disc 107 of rubber or other suitable
material. While the chambers are filling, the air passes upwardly around
the disc 107 and through the openings 104 without disturbing the said disc.
When the compressed air is admitted to the chamber at pumping pressure,
however, the force is sufficient to raise the disc 107 against the lower face of
the cap 103 and close the openings 104.
The primary valves 67 are operated automatically by the floats 93 and
weights 90, in a manner to be hereinafter described. It is sometimes desirable,
however, to operate these valves manually. This is done by devices which will
now be described. On one side of the box or case 68 of each of the primary
valves is secured a screw-plug 110 (Fig. 11), through which passes a rock-
shaft 111. Secured to, or formed integral with, the inner end of the rock
shaft 111 is an enlarged portion 112 which is provided with two arms 113. The
arms 113 (Fig. 14) embrace a pin 114 which is secured to the bell-crank lever S1.
The arms 113 are such a distance apart as to allow the bell-crank. lever 81 to
perform its, usual travel without causing the pin 114 to come in contact with the
said arms.
Secured to the outer end of the rock shaft 111 is a bell-crank
lever 115. The two adjacent arms of the bell-crank levers 115 are connected
by a rod or link 116 (Fig. 16), and the outer arms of the said levers have attached
to them suitable wires or rods 117 which extend upwardly so that they can be
manually operated. The side of the box or casing 68, opposite to that containing
the screw-plug 110, is preferably provided with a screw-plug 118 (Fig. 11) to
give access to the interior of the said casing 68.
120 (Fig. 17) represents the reservoir of the air compresser which supplies the
air for operating the pump. The pipe 56 leading to the main valve 46 is
connected with a pipe 56. which communicates with the reservoir 120, and
between the pipes 50 and 56b is a throttle valve 121, by means of which the

page_text: supply of air through the pipe 50" to the valve casing 46 may be diminished, or if
desired, completely shut off. The valve 121 may be operated by means of a
hand-wheel 122, or by any other suitable means. The valve 121 should be
placed at a point within access of the cperator and may be placed near the
reservoir 120, as shown in the drawings, or at any desired distance from said
reservoir provided access may be had to it. The supply pipe 76 leading to the
primary valves 67, is connected with the pipe 56b between the reservoir 120 and
the valve 121, so that the operation of the valve 121 will not in any way affect
the supply of air passing through the pipe 76; or, if so desired, the pipe 76 may
be connected to the reservoir 120 independently of the pipe 56b, as the same
result may be obtained in this manner. The rate of discharge of the pump
is regulated by the valve 121, as the farther this valve is opened the greater will
be the pressure in the pipe 56", and consequently the more rapid the discharge
of the pump.
In practice, the valve 121 is rarely if ever completely opened as
it is desirable to have the pressure in the reservoir somewhat higher than that
required for pumping. It follows from this that the pressure in the pipe 76
is higher than that in the pipe 56". This, for reasons which will be hereinafter
explained, is an important feature in obtaining some of the objects of my
invention.
The operation of my pump is as follows: Supposing the parts to be in the
position shown in Fig. 1, and the chamber 21 full of water and the chamber 22
empty, the compressed air passing down the pipe 56" to the valve casing 46
enters the chamber 21 through the port 43 driving the float-valve 63 downward
as it enters. This will force the water contained in the chamber 21 up through
the pipe 35, valves 38 and connecting-pipe 39, to the discharge pipe 40.
At the
same time, the port 43 leading to the chamber 22 being opened through the
valve 50 to the exhaust port 44, the air contained in the said chamber 22 will
pass out through said ports and allow the water surrounding the pump to enter
the chamber 22 through the inlet valves 27 and openings 24. As the water
falls in the chamber 21, the float 93 will fall with it until detained by means
of the stop 94. As the rod 91 of the float 93 is below the pin 85 of the bell-
crank lever 81; the downward motion of said float 93 in the chamber 21
will not in any way affect the said bell-crank lever, and as the
water rises in the chamber 22, theweight 90 in said chamber
will rise with it until prevented by the stop 95. The slot 86 in the
upper end of the rod 87 will allow the weight 90 to rise without affecting the bell-
crank lever $1 of the primary valve 67 connected with the chamber 22.
When the water in the chamber 21 has fallen to near the end of the pipe 35,
the weight 90 will descend with it and by means of the rod 87 will pull the end
of the bell-crank lever 81 downward and force the piston 72 of the valve 67
outwardly, thus connecting the air pipe 70 with the air supply pipe 76. The air
will now pass from the supply pipe 76 through the pipe 70 into the right-hand
end of the main valve 46. As the left-hand end of the main valve casing 46
is in communication through the ports 51 and 43 with the chamber 21 which
contains air at pumping pressure, which pressure, as has been hereinbefore
explained, is less than that supplied by the pipe 76, the piston 48 will be forced
towards the left-hand end of the valve 46 until the left-hand port 43 is closed.
At the same time, the end of the piston 48 will close the left-hand port 51 and shut
off communication between that end of the valve casing 46 and the chamber 21.
The pressure will then immediately rise in this end of the valve casing until equal
to that in the opposite end, as both are now in communication with the air
supply pipe 76. This will hold the piston 48 and valve 50 in this position
until the chamber 22 is completely filled with water: the valve 50 being in a
reversed position to that shown in Fig. 3, so that the right-hand port 43 will
still be in communication with the exhaust 44. As soon as the chamber 22
is completely filled, the float 93 at that end will be forced upward into the
|dome 100, and by means of the pin 85 will force upwardly the end of the bell-

page_text: crank lever 81, thus drawing the piston 72 of the valve 67 inwardly and con-
necting a pipe 71 with the exhaust 76"; thus exhausting the air from the left-
hand end of the valve casing 46. This will immediately cause the piston 48 to
move further towards the left until the right-hand port 51 is put into com-
munication with the right-hand end of the valve casing 46. The compressed
air will now pass down through the port 51 into the port 43 and gradually
fill the same up to the pumping pressure without causing any jar or shock on
account of the contracted opening 53. As the opening 53, however, is larger
than the supply opening, the valve will remain in this position until the air in
port 43 is raised to practically working pressure, when it will force the piston 48
completely to the left, thus connecting the right-hand port 43 with the air-supply,
and the left-hand port 43 with the exhaust." The above operation will then be
reversed; the water being forced out of the chamber 22 and allowed to enter
the chamber 21. It will be seen by reference to Fig. 2 that the above described
operation could not be properly performed if there was no play between the
piston 48 and valve 50, for if the valve 50 was rigidly secured to the piston,
the port 43 would be opened at practically the same time as the port 51.
is to be understood, however, that in the operation of the pump the parts are
never in the position shown in Fig. 2, for when the piston 48 is in the position
shown in Fig. 2, the valve 50 is either in the position shown in Fig. 3. or in
the reversed position, and when the valve is in the position shown in Fig. 2, the
piston will be in such a position as to uncover one of the ports 51.
It
In the above operation, if the chamber 22 had become filled with water before
the chamber 21 had become emptied, the operation would be the same except
that the piston 48 would make but a single stop in its travel; for, when
the chamber 22 became filled and by raising the float 93 connected the left-
hand end of the valve 46 with the exhaust, there would be no movement of the
piston 48, as the right-hand end of the said valve would also be connected with
the exhaust, so that, when the chamber 21 was emptied and connected the
right-hand end of the valve 46 with the air supply, the said valve
would
until it uncovered the right-hand port
allowed the compressed air to pass down the same. In this case,
the valve 52 in the left-hand port 51 would be forced upwardly to
close the opening 53 leading from said port to the left-hand end of the valve 46,
and thus prevent the said end from being filled with air at the pumping pressure,
or otherwise the operation of the pump would be delayed until enough air was
exhausted from the chamber 21 to reduce the pressure considerably below the
pumping pressure.
move over
51 and
In case the piston 48 became clogged by sediment during a period of disuse, it
might be found that the pump would not operate when the compressed air was
turned on. In this case the air would first be completely closed from the
supply pipe 56 by means of the throttle valve 121. This, as previously
described, would not interfere with the supply of air though the pipe 76 to the
primary valves 67. These valves could now be operated by alternately pulling
upwardly on the two wires 117. This would throw the air pressure first on one
and then the other end of the piston 48 until the same became loosened, when
the air could be turned on the supply pipe 56 so that the pump could proceed to
operate automatically.
In a pump having but one chamber, I use a main valve such as is shown in
Fig. 19.
The lower part of this valve is formed of a casting 125 which is
secured to the top of the pump chamber. The pump chamber may be in all
respects like one of the chambers 21 and 22, and is provided with similar floats
and weights. Formed in the casting 125 is a main port 126 and an exhaust
port 127.
Secured to the casting 125 is a valve casing 128 in which slides a
piston 129 controlling a slide valve 130. Connecting the port 126 with the end
of the valve casing 128 in an auxiliary port or by-pass 131 similar to one of the
ports 51 previously described in connection with the double chambered pump. In

page_text: the port 131 is a check-valve 132 which seats downwardly against a seat 133
formed in a valve plug 134. This form of check-valve is more reliable, when
pumping at a low pressure, than that shown in Fig. 2. The primary valve
casing 1:35 has formed in it an air supply port 136, two exhaust ports 137 and
two ports 138, each of which is connected with one end of the main valve
casing 128.
In the piston 140 of the primary valve are three depressions 141
arranged to alternately connect each of the ports 138 with the supply 136 and one
of the exhaust ports 137. Formed in the casing 135 is a passage 142 for
equalizing the pressure on the ends of the piston 140. 143 is a portion
similar to the portion 112 previously described.
Carried on the same rock shaft
as the portion 143 are two arms 144 to which are secured wires 145 for manually
operating the piston 140.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is―
1. In a compressed-air water elevator, two chambers each provided with a
valved inlet and a valved delivery, a main valve for controlling the admission of
air to, and exhaust thereof, from said chambers, and means for alternately and
independently connecting each end of said main valve with the air supply and
exhaust by the rise and fall of the liquid in said chambers, whereby the shifting
of the main valve is controlled by the admission and exhaust of air due to, the
conjoint action of both chambers.
2. In a compressed-air water elevator, two chambers each provided with a
valved inlet and a valved delivery, a main valve for controlling the admission of
air to and exhaust thereof from said chambers, two independent primary valves
each adapted to control both the supply and exhaust to operate said main valve, a
primary valve being in connection with each of said chainbers, a float in each of
said chambers for moving the primary valve connected therewith in one direction
independently of the other primary valve, a weight in each of said chambers for
moving the primary valve connected therewith in the other direction inde-
pendently of the other primary valve, and operating connections between said
primary valves and said main valve, whereby said main valve is actuated by
the conjoint action of said primary valves.
3. In a compressed-air water elevator, two chambers each provided with a
valved inlet and a valved delivery, a piston for controlling the admission of air
to and exhaust thereof from said chambers, a double-acting primary valve for
each of said chambers, one communicating with one end of said piston, and the
other with the other end of said piston, and means for independently operating
each of said primary valves by the rise and fall of the liquid in its respective
chamber.
4. In a compressed-air water elevator, a chamber for containing the liquid to
be raised and provided with a valved inlet and a valved delivery, an air-supply
for supplying compressed air to force out the contents of said chamber, a valve
controlling the admission of air from said air-supply to said chamber through
a main port, a secondary port for supplying air to said chamber to raise the
pressure in the same, and means for opening said latter-named port by, the
initial movement of said valve before the main port is opened.
5. In a compressed-air water elevator, a chamber for containing the liquid to
be raised and provided with a valved inlet and a valved delivery an air-supply
for supplying compressed air to force out the contents of said chamber, a valve
controlling the admission of air from said air-supply to said chamber through
a main port, a secondary port for supplying air to said chamber to raise the
pressure in the same, means for opening said secondary port by the initial
movement of said valve before the main port is opened, and means for retarding
the movement of said valve after said secondary port is opened until the pressure
in said chamber is raised to substantially the pumping pressure.

page_text: 6. In a compressed-air water elevator, a chamber for containing the liquid
to be raised and provided with a valved inlet and a valved delivery, a main
air-supply for supplying compressed-air to force out the confents of said chamber,
a valve controlling the admission of air from said main air-supply to said
chamber through a main port, a second air-supply, a secondary port for supplying
air to said chamber from said second air-supply to raise the pressure, and means
for opening said secondary port by the initial movement of said valve.
7. In a compressed-air water elevator, a chamber for containing the liquid
to be raised and provided with a valved inlet and a valved delivery, a main
air-supply for supplying compressed-air to force out the contents of said chamber,
a valve controlling the admission of air from said air-supply to said chamber
through a main port, a second air-supply, a secondary port for supplying air
to said chamber from said second air-supply to raise the pressure in said chamber,
means for opening said secondary port by the initial movement of said valve, and
means for retarding the movement of said valve after said secondary port is opened
until the pressure in said chamber is raised to substantially the pumping
pressure.
8. In a compressed-air water elevator, a chamber for containing the liquid to
be raised and provided with a valved inlet and a valved delivery, a main air-
supply for supplying compressed-air to force out the contents of said chamber, a
valve controlling the admission of air from said main air-supply to said chamber
through a main port, a second air-supply, a secondary port for supplying air to
said chamber from said second air-supply to raise the pressure, means for opening
said secondary port by the initial movement of said valve, and a check valve in
said secondary port to prevent back flow.
9. In a compressed-air water elevator, a chamber for containing the liquid
to be raised and provided with a valved inlet and a valved delivery, a main
air-supply for supplying compressed-air to force out the contents of said chamber,
a valve controlling the admission of air from said main air-supply to said chamber
through a main port, a piston actuating said valve, a second air-supply for
supplying air to the ends of said piston, and a secondary port leading from the
cylinder of said piston to said main air-port and having a larger area than said
second air-supply opening, whereby the uncovering of said secondary port will
reduce the pressure in said cylinder and retard said valve until the pressure in
said chamber is raised to substantially the pumping pressure.
10. In a compressed-air water elevator, a chamber for containing the liquid
to be raised and provided with a valved inlet and a valved discharge, a main
air-supply, a main valve controlling said main air-supply, a second and separate
air-supply for operating said main valve, an auxiliary valve for controlling said
second air-supply, a mechanism for automatically operating said auxiliary valve,
a valve for cutting off said main air-supply independent of said second air-
supply, and means for manually operating said auxiliary valve while said main
air-supply is cut off.
11. In a compressed-air water elevator, two chambers each provided with a
valved inlet and a valved discharge, two main air-ports, one communicating with
each chamber, a suitable air-supply adapted to be put in communication with said
main air-ports, an exhaust port also adapted to be put in communication with
said main air-ports, a valve for closing off the main air-port in communication
with an emptied chamber from both the air-supply and the exhaust while the
main air-port of the filling chamber is in communication with the exhaust, and
means for maintaining said latter communication until said latter chamber is
filled.
12. In a compressed-air water elevator, two chambers each provided with a
valved inlet and a valved discharge, two main air-ports, one communicating with
each chamber, a suitable air-supply adapted to be put in communication with
said main air-ports, an exhaust port also adapted to be put in communication with
said main air-ports, a valve arranged to close off the main air-port of the

page_text: emptied chamber from both the air-supply and the exhaust while the main air-
port of the filling chamber is in communication with the exhaust, and means for
retaining said valve in said position until said latter chamber is filled.
13. In a compressed-air water elevator, two chambers, each provided with a
valved inlet and a valved discharge, two main air-ports, one communicating with
each chamber, an air-supply, an exhaust, a valve adapted to alternately connect
each of said main air-ports with the air-supply and with the exhaust, secondary
air-ports for supplying air to said chambers to raise the pressure of the same,
a piston controlling said secondary ports, and means for actuating said valve by
the movement of said piston to move said valve a less distance than said piston.
14. In a compressed-air water elevator, two chambers, each provided with a
valved inlet and a valved delivery, two main air-ports, one communicating with
each chamber, an air supply, an exhaust, secondary air-ports for supplying
air to said chambers to raise the pressure in the same, a piston acting as a valve
for said secondary ports, a valve for said main ports, and loose connections
between said valve and said piston, whereby said piston will move a greater
distance than said valve.
15. In a compressed-air water elevator, two chambers each provided with a
valved inlet and a valved discharge, two main air-ports, one communicating with
each chamber, a main air-supply adapted to furnish compressed-air to said main
air-ports, a suitable valve controlling the admission of air to said main ports, a
piston for actuating said valve, a secondary air-supply adapted to supply air
at a higher pressure than said main air-supply for moving said piston, passage-
ways between said secondary air-supply and said main ports, and means for closing
said latter named passageways while one of said main ports is cut off from the
main air-supply and the other of said main ports is in communication with
the exhaust.
16. In a compressed-air water elevator, a main chamber provided with a
valved inlet and a valved discharge, and air-supply for supplying compressed-air
to force out the contents of said chamber, a float in said chamber or controlling
said air-supply, a dome or secondary chamber above said main chamber for
receiving said float, and a relief valve for said dome adapted to allow the escape
of air from said dome at a low pressure but to be closed by a high pressure.
Dated this 1st day of June 1899.