Note: Descriptions are shown in the official language in which they were submitted.
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There is a wide spread need to provide, reliable, low , and reasonably priced water well
handpumps to rural water supply areas in under-developed countries of the world and some rural areas of the
developed countries. Many ofthe handpumps presently being installed in under-developed countries involve the
use of metal linkage rods connecting a surf2ce mounted drive unit to tlle pump unit installed in the water within a
water well. In addition, many of these handpumps have complex seals and connecting linkage. If breakage occurs,
removal and repair of these handpumps are difficult for relatively unskilled labour available in the rural areas. This
situation often results in the water well being out of service until skilled labour and hoisting equipment is brought to
the well site. The ordering and delivery of, r Gd speciality components may cause long delays for repair of
the handpump. In some rural areas of under-developed countries, people rely upon the continuous operation of the
local water well as the only community drinking water supply. The long down-time of an existing water well while
waiting for a r ' Gd part is not acceptable. The reliable operation, low ' and self reliance with
respect to repair of deep well handpumps in these rural areas of developing countries is paramount.
The present handpump invention provides , ., . . to the drive unit, riser pipe and pump unit and
uses standard fiKings which can of en be replaced by improvised components to keep the pump operational until the
proper parts are delivered to the rural village. The blacksmith in rural areas of many under-developed countries is
often the highest level of skill available. Should l~ G~ parts not be readily available, due to isolated
locations or any other reason, the local blacksmith could, with some ingenuity, repair a damaged handpump part to
make the handpump workable until a replacement part is obtained.
The handpump will be assembled at the point of r ' Gl and delivered in a packing crate to the well
site. The package will include the complete drive unit, handpump lever handle, pump unit and flexible riser pipe in
a coil. Tlle installation and operational process will be presented by pictorial description. The handpump
installation process will be simple and will involve the use of standard tools and manual labour to assemble and
lower the handpump unit into the deep well. The removal and disassembly of the pump and drive units to check and
replace seals will be effected by average skilled labour following a pictorial description.
The handpump consists of a drive unit fixed at ground surface over an existing deep water well, a
handpump handle lever which operates the drive unit, a pump unit located in the water well and a connecting
flexible riser pipe. The downstroke of the handpump lever handle drives a drive un it piston down forcing the water
down the flexible riser pipe increasing the water pressure between the drive unit piston and a hollow piston rod
located in the pump unit. Tlle hollow pump rod has a piston disc and a check valve on the upper and lower ends.
The increase in water pressure drives the hollow pump rod downward and compresses the helical coil spring located
at the bottom of the pump unit. As the helical coil spring is compressed, water enters tlle l1OIIOW pump rod through
drilled openings and enters a storage chamber created between reservoir cylinders of different sizes. As the l1elical
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coil spring rcbounds to the static position, this volume of water is forced up the flexible riser pipe and through the
drive unit piston disc openings to the discharge nozzle.
Many different types of pumps exist and a few use the principle of transferring kinetic energy from a drive
unit to stored potential energy vithin a helical spring. Others use an expanding storage chamber whereby water is
5 forced to expand the storage chamber which, when pressure is relieved, forceswater to the surface.
One spring based pump device is disclosed in U.S. Pat. No. 4,616,981, issued October 14, 1986. This pump
uses a .1. ' ~'y driven pump unit comprising of a reservoir cylinder, drive piston, tubin~ and valves. The pump
was designed for use in water or oil production and is capable of being connected to a series of production wells for
large recovery volumes. The drive unit is complex, expensive to mass produce and not suited to rural areas of
10 developing countries where local maintenance and repair are important. The pump unit has a piston disc located at
the bottom of a piston rod. A check ball is placed in each of many small passages located in the piston disc which
permits flow in the storage chamber. The provision of many small openings with a check ball operation is subject to
the collection of grit and consequent leakage.
AnotherpumpdeviceisdisclosedinU.S.Pat.No.4,297,087,issuedOctober,1981. Thispumpusesa
15 surface mounted drive unit which provides a cyclically applied pressure to the fluid in a riser pipe to activate the
subsurface pump unit. The fluid pressure in the pump unit forces a piston rod downward to compress a spring and
draw fluid from the well into the pump chamber. There are a number of l;a~ with this pump device. The
production volume of fluid generated within the pump unit is the result of a difference in reservoir cylinder volumes
as the piston rod moves from one reservoir to another. The piston rod slides vertically at the connection point
20 between upper and lower reservoir cylinders. Due to possible seating difticulties at the bottom end of the piston rod
the piston rod may wear unevenly creating unnecessary friction as the piston rod slides downward. Tlle drive unit
operates on the principle of driving a piston disc downward which increases the water pressure within the riser pipe
connected to the pump unit. The piston disc ofthe drive unit has an o-ring seal which passes a discharge outlet
during each pump cycle. This design provides the opportunity for excessive wear to occur on the o~ring seal. In
25 addition, the drive unit is complex and consists of an electric motor which operates a cam and spring mechanism to
drive the drive unit piston. This technology is not appropriate in rural, where electric power and skilled
operators are in short supply but where manual labour is readily available.
The present invention improves on the known principle of expanding storage chamber and the energy
transfer of kinetic energy from a drive unit to a sub-surface pump unit. A piston seal and check valve are provided
30 at the upper and lower ends of a hollow piston rod to use an expanding stora~e chamber to provide a p~lmping
capacity suitable for rural areas of developing countries. Tl~e hollow piston rod slides vertically within the reservoir
cylinders on piston discs located at the extreme upper and lower ends. Tlle hollow piston rod llas single spring
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check valves at the upper and lower ends each with a seating seal. This is an ;...~,-v . . over the ball type check
valve and results in a simpler pump unit. The pump unit of the present invention is made up of threaded
components for easy disassembly and easy inspection of pistons and check valves.The helical coil spring is suitable for various water depth applications. The spring may be constructed of
5 standard carbon steel wire diameter on a lathe to a specifled number of coils per design length. The spring materials
may be upgraded to stainless steel with minimal cost depending on the number of handpumps ordered. The spring
is not pre-tensioned so the removal and reassembly only requires removing the threaded bushing which fits into the
bottom of the pump unit reservoir cylinder.
The drive unit consists of a reservoir cylinder which pivots at the base where it is connected to the
10 supporting metal channel structure. This illlLJIu . to the manual drive unit prevents ' 'i~, and
excessive wear on connecting bushnngs and on the seal on the piston disc in the reservoir cylinder. A simple valve
system consisting of a linkage rod disc and a piston disc opens and closes during the pressure and discharge parts of
the pump cycle.
The flexible riser pipe is an ;III,VIU . . ' over the rigid drop pipe and metal linkage rods used in plunger
15 type pumps and over two pipe systems which use one pipe to apply energy to the pump unit and another to deliver
water to the surface.
The principle object of the present invention is to provide an improved handpump which utilizes standard
fittings and simple construction to produce a device which is reliable, simple to maintain and can easily be repaired
by local people in rural areas of developing countries. The main application is the pumping of water from depths as
20 much as 3 û metres to the ground surface. The efl'ort required to operate the handpump by means of the handpump
lever handle is dependent on the depth of the water in the wel l and the spring ~ ,;I,;I;Ly coefficient. The
handpump is designed to enable a young adult to apply sufficient force tv pull/push the handpump lever handle
downward.
The invention, as exemplified by a preferred; ' " t, is described with reference to the drawings in
25 which:
Figure I is an elevation cross section of an embodiment of the drive unit.
Figure 2 is an elevation cross section of an embodiment of the pump unit.
Figure 3 is an elevation cross section ofthe drive unit, flexible riser pipe and pump unit, sllowing the
handpump lever handle unit, ergonomic III~,~IDU~I ', drive unit pivot point and water flow in the downstroke and
30 upstroke motions of the handpump operation.
Figure 4 is a plan view of the drive unit handpump lever handle, sho~vn in Figure 3, showing the pinned
connections to a channel and plate support bracket.
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Figure 5 is an elevation end view of the drive unit, shown in Figure 3, showing tlle pinned connection of the
handpump lever handle to the drive unit and support structure.
Referring to the drawings, the embodiment of the invention shown, a handpump shown comprises a drive
unit as shown in Figures I & 3, a pump unit as shown in Figure 2 & 3, a flexible riser pipe as shown in Figure 3,
5 handpump lever handle as shown in Figure 3 & 4, and a drive unit support structure as shown on Figure 4 & 5.
Thedriveunit,Figure l,comprisesadriveunitreservoircylinderlandanoutletnozzlecomprisingofatee
2 nipple 3 and elbow 4. The elbow 4 is connected to the nipple 3 with a swivel connection 5 for use in priming the
handpump. The top of the reservoir cylinder I is sealed with a drilled cap 6 which permits the drive unit metal
linkage rod 7 to move in a vertical direction. The reducing coupling 13 and a male insert adapter 14 are located at
the bottom ofthe reservoircylinder 1. The flexible riser pipe 16 is anached to the male insert adapter 14 with a
metal r~mrrrcei~n band 15.
The pipe cap 12 is attached to the bonom of the drive unit metal linkage rod 7. The linkage rod disc 8 is
fixed to the lower end of the metal linkage rod 7 above the pipe cap 12. The drive unit piston disc 9 is free to slide
on the metal linkage rod 7 between the pipe cap 12 and the linkage rod disc 8. Small water passage openings ll in
15 the drive unit piston disc 9 permit passage of water to tlle upper part of the reservoir cylinder I during tlle pump
upstroke operation. Tlle linkage rod disc 8 is attached to the drive unit metal linkage rod 7 to provide the sealing
mechanism regulating the passage of water through the small water passage openings 11 between the downstroke
and upstroke pump operations. A leather seal 10 is anached to the outside edge of the piston disc 9 which serves as
a friction seal to prevent water from passing between the wall of the drive unit reservoir cylinder 1 and the drive unit
20 piston disc 9 during the downstroke operation of the drive unit.
The handpump lever handle 32 is connected to the drive unit support bracket 36 by a bolted pin connection
33 as shown on Figure 3. The support bracket 36 is connected to a metal support structure 37 which are fastened to
the concrete slab as shown on Figure 5. The handpump lever handle 32 is constructed of metal tubing in a
rectangular plan layout as shown on Figure 4. The handpump lever handle 32 is connected to the drive unit metal
25 linkage rod 7 by a bolted pin through an eye bolt linkage 34 at the top end of the linkage rod 7. Tlle two closing
sections of the handpump lever handle end are connected 35 with a nut and bolt. Metal spacing washers 38 are
provided at the pinned connection 33 and at the handpump lever handle connection 3S as shown on Figure 4, to
prevent sideways slippage of the handpump lever handle during the handpump cycle operation. As the metal
linkage rod 7 moves vertically during the pumping operation the metal linkage rod 7 Inoves in tlle l1orizontal
30 direction. To ' horizontal movement between the drive unit reservoir cylinder I and the metal linkage
rod 7 the drive unit reservoir cylinder is pinned at a pivot point 39 which permits the reservoir cylinder to rotate thus
preventing uneven wear on the leather seal 10 and the drilled cap 6.
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Thedriveunit,Figurel,islinkedtothepumpunit,Figure2,bymeansofaflexibleriserpipel6. Theriser
pipe 16 is attached to the drive and pump units by a male insert adapter 14 and a metal ~,UIII~ II band 15. The
riser pipe 16 serves to transfer input energy from the downstroke pump operation and water flow up the riser pipe 16
during the upstroke pump operation.
The pump unit, Figure 2, is placed below the water surface of a deep well for the purpose of pumping water
to the ground surface. The main components of the pump unit are a small reservoir cylinder 17 a large reservoir
cylinder 24 a hollow pump rod 22 and a helical coil spring 29. The small reservoir cylinder 17 and the large
reservoir cylinder 24 are connected with a threaded reducing bushing 21. Water is free to pass between the small
reservoir 17 and the large reservoir cylinder 24 through a water passage opening in the connecting reducing bushing
21. The bottom of the pump unit is fined with screen 31 and a threaded insert bushing 30 which supports the helical
coil spring 29. A reducing coupling 13 is fined to the top of the small reservoir cylinder 17.
The hollow pump rod 22 is free to move vertically within the small reservoir cylinder 17 and the large
reservoir cylinder 24 as the helical coil spring 29 compresses and rebounds. The hollow pump rod 22 has small
water passage openings 23 which permit water to enter the space between the small reservoir cylinder 17 large
reservoir cylinder 24 and the hollow pump rod 22 which occurs during the pump cycle operation. The pump unit
piston disc 19 has a leather seal 20 anached to the outside edge of the piston disc 19, which serves to prevent water
from passing between the wall of the small reservoir cylinder 17 and the piston disc 19 during the operation of the
pump unit.
The pump unit piston disc 25 has a leather seal 26 anached to the outside edge of the piston disc 2S which
serves to prevent water from passing between the wal I of the large reservoir cylinder 24 and the pum p un it piston
disc 25 during the operation of the pump unit. Check valves 18 & 28 are used to provide directional flow of water
during the pump cycle operation. The helical coil spring 29 is supported by a threaded insert bushing 30 at tlle
bottom of the pump unit. A guide plate 27 is located on the top of the helical coil spring 29 which supports the
hollow pump rod 22. The insert bushing 30 supports the helical coil spring 29 hollow pump rod 22 and tlle ~veight
of water in the riser pipe 16 to the ground surface.
The operation of the handpump is based on the work energy transferred hydraulically from the downstroke
of the handpump lever handle 32 which increases the water pressure within the fle?~ible riser pipe 16, due to the
combined ætion of the piston discs 9, 19 & 25, and check valves 18 & 28. The increase in water pressure in the
riser pipe 16 forces the llollow pump rod 22 down which depresses the helical coil spring 29, and increases tlle
volume of space between the hollow pump rod 22 and the large reservoir cylinder 24. The increase of available
volume space draws additional water through a one way check valve 28. As the helical coil spring 29 e~pands to the
normal static level, the water between the hollow pump rod 22 and the large reservoir cylinder 24 is forced up~vard
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to the ground surface. The check valves 18 & 28 permit directional flow of the water within the pump and drive
units. Leather discs 10, 20 & 26 are attached to the piston discs 9, 19 & 25 to prevent the leakage of water at tll;:
reservoir cylinder walls 1, 1~ & 24. The handpump system relies upon these seals to maintain the internal pressure
within the drive unit, the flexible riser pipe and the pump unit.
The detailed operation ofthe handpump downstroke operation is described as follows:
The handpump is at rest when the handpump lever handle 32 is at the highest point at the upstroke position
as shown on Figure 3. The handpump drive unit, Figure I, flexible riser pipe 16 and pump unit, Figure 2, are
primed with water through the elbow 4 by rotation at the swivel connection 5 prior to the first use of tlle handpump.
The check valves 18 & 28 and piston seals 2û & 26 prevent water leakage into the water well.
To start the handpump operation the operator pusheslpulls the handpump lever handle 327 downward to the
downstroke position as shown on Figure 3. As the handpump lever handle is brought to the downstroke position the
metal linkage rod 7 is forced down the drive unit reservoir cylinder 1. The initial downward motion of the metal
linkage rod 7 results in the sealirJg of the linkage rod disc 8 against the drive unit piston disc 9. This action closes
the small water passage openings 11 in the piston disc 9, thus preventing the passage of water to the nozzle outlet 3
& 4. At the same time the leather seal 10 prevents water from leaking between the drive unit reservoir cylinder 1,
and the piston disc 9. The downward motion of the metal linkage rod 7 linkage rod disc 8 and lhe sealing action of
the piston disc 9 forces water down the flexible riser pipe 16, to the pump unit. The water flowing down the riser
pipe 16 closes the check valve 18 on the hollow pump rod 22. The closing of the check valve 18 and the friction
seal of the leather seal 20, on the small reservoir cylinder 17 results in an increase of water pressure between the
drive unit piston disc 9 and the hollow pump rod 22.
The water pressure increase in the riser pipe 16 forces the hollow pump rod 22 downward , C~ lg the
helical coil spring 29. The downward movement of the hollow pump rod 22, results in an increase in the volume of
space between the hollow pump rod 22 and the large reservoir cylinder 24. Water flows upward from the water well
through the check valve 28 into the hollow pump rod 22 and through small water passage openings 23, filling the
increasingvolumeofspacebetweenthelargereservoircylinder24andthehollowpumprod22abovethehelical
coil spring 29.
The downstroke handpump operation results in a series of effects, comprising:
a downstroke action of the handpump lever handle 32, directs the metal I inkage rod 7
downward in the drive unit reservoir cylinder I and;
the linkage rod disc 8 is seated against the drive unit piston disc 9 il~ the drive unit reservoir
cylinder I preventing water from flowing upward througll small water passage openings 11 in the
piston disc 9 and;
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the downward ætion of the metal linkage rod 7 directs the piston disc 9 down the reservoir
cylinder 1 and results in the friction seating of the piston disc 9 and the leather seal 10 against the
drive unit reservoir cylinder I and;
the downward movement of the metal linkage rod 7 the seating of the linkage rod disc 8
against the drive unit piston disc 9 and the friction sealing of the leather seal 10 against the
reservoir cylinder wall 1, results in the flow of water down the flexible riser pipe 16 to the pump
unit and;
the flow of water down the flexible riser pipe 16 to the pump unit closes the check valve 18
located at the top of the hollow pump rod 22 and leakage of water is prevented by the frjction action
of the piston disc 19 and the leather seal 20 against the small reservoir cylrnder 17 which sustains
the water pressure increase in the riser pipe 16 and;
increased water pressure in the flexible riser pipe 16 forces the hollow pump rod 22
downward which compresses the helical coil spting 29 increasing the volume of spæe between the
large reservoir cylinder 24 and the hollow pump rod 22 above the coil helical coil spring 29 and;
water enters the hollow pump rod 22 through a one way check valve 28 and flows through
small water passage openingS 23 into the increasing volume between the large reservoir cylinder 24
and tne hollow pump rod 22 above the compressed helical coil spring 29 and;
water is prevented from leaking to the water well from the water filled volume space
between the large reservoir cylinder 24 and the hollow pump rod 22 by the friction action of the
piston disc 25 and the leather seal 26 against the large reservoir cylinder 24 and closing of the
check valve 28.
The detailed operation of the handpump upstroke operation is described as follows:
The upstroke or lifting of the handpump lever handle 32 separates the linkage rod disc 8 from the drive unit
piston disc 9 and permits water to flow through the small water passage openings 11 in the piston disc 9. As a result
of the downstroke pump ætion, the water pressure in the drive unit is greater below the piston disc 9 than above the
piston disc 9 which is open to the atmosphere. The action of separating the cylinder disc 8 and the piston disc 9
provides a release of water through the small water passage openings 11.
The rebound of the helical coil spring 29 from the compression position during the downstroke operation
forces the flow of water up the flexible riser pipe 16 and through the small openings 11 in the drive unit piston disc
9 and out the no7~1e 3 & 4. As the helical coil spring 29 begins to rebound to the pre-pump position, the check
valve 28 closes and check valve 18 opens. The rebound of the helical coil spring 29 reduces the volume between the
large reservoir cylinder 24 and the hollow pump rod 22. The water dra~vn into this volume during the downstroke
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part of the pump operation is forced into the hollow pump rod 22 through small water passage openings 23 and
upward through the open check valve 18 through the riser pipe 16 to the drive unit and the atmosphere. The pump
unit piston disc 25 has a leather seal 26 which friction seals the piston disc 25 against the large reservoir cylinder 24
thus preventing leakage of water into the well during the rebound action of the helical coil spring 29.
The upstroke handpump operation results in a series of effects, comprising:
a upstroke action of the handpump lever handle 32 and the comnecting metal linkage rod, 7; and
a separation of the linkage rod disc 8 from the drive unit piston disc 9 permitting water to flow
through small water passage openings 11 and
areboundofthecompressedhelicalcoilspring29forcinganupwardmovementofthehollow
pump rod 22 and
the rebound of the helical coil spring 29 and the upward movement of the hollow pump rod 22
reduces the volume of space between the large reservoir cylinder 24 and the hollow pump rod 22 and thus
forcing water through the small openings U into the hollow pump rod 22 and up the flexible riser pipe 16 to
the drive unit; and
the opening of a check valve 18 perm itting the flow of water up the flexible riser pipe 16 and
the closing of a check valve 28 preventing the flow of water into the well; and
an upward movement of the piston disc 25 and the friction sealing of the leather seal 26 against tbe
large reservoir cylinder 24 thus preventing leakage of ~vater back into the well.
A descriptive summary of the handpump downstroke and the upstroke operations fol lows:
The drive unit, Figure I & 3, is placed over an existing water well casing at the ground surface and bolted to
a concrete slab as shown in Figure 3. The pump unit, Figure 2 & 3, is placed at depth within a deep water well. The
pump unit is supported vertically by the surface mounted drive unit and the connection of a flexible riser pipe,
Figure 3. The handpump is primed with water and all to tlle drive unit outlet. The drive and pump units internal
components include check Yalves which provide directional water flow and leather covered piston discs to prevent
water leakage as the pistons slide against the reservoir cylinder walls, The downstroke motion of the llandpump
lever handle forces a drive unit pistcn disc downward forcing water down the riser pipe to the pump unit closing a
check valve and results in the increase of water pressure between the pump unit piston disc and the hollow pump rod
in the pump unit as shown in Figure 3. The increased water pressure compresses a helical coil spring. At the same
time well water is drawn into the volume of space increasing between reservoir cylinders of different sizes. The
upstroke of the handpump lever handle results in the reverse sequence of events and water fiows to tlle drive unit
tbrough the riser pipe as the compressed helical coil spring rebounds to tlle pre-pump position wllicll forces tlle
water f lled reservoir cylinder to expel the water drawn in during the downstroke operation.
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Kinetic energy is applied to the pump unit by the downstroke of the handpump lever handle increasing
water pressure within the drive unit, flexible riser pipe, and pump unit. The kinetic energy is converted to potential
energy as the internal water pressure compresses the helical coil spring in the pump unit drawing water into an
increasing volume of space between reservoir cylinders of different si~es. The upstroke release of the handpump
5 lever handle converts the potential energy stored in the heliQI coil spring causing it to rebound and force the
additional water drawn into the reservoir cylinder to flow up the riser pipe to the ground surface. The rate of water
flow depends on the frequency of the d~ .. ' 'u~ h~ cycle of operation and the internal handpump
dimensions.
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