FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF INVENTION
A self driven bellow type water pump
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 025, Maharashtra, India, an Indian Company
INVENTOR
Khedkar Parag Prabhakar, Crompton Greaves Limited, Technology Cell, Switch Gear (S3) Division, A3 MIDC, Ambad, Nashik 422010, Maharashtra, India, an Indian National
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed :

FIELD OF INVENTION
This invention relates to a self driven bellow type water pump.
This invention relates particularly to a self driven bellow type water pump for use as a booster or auxiliary pump to an electrical pump for pumping water into overhead tanks or to higher levels.
BACKGROUND OF INVENTION
Water pumped or flowing from a source of supply or reservoir into distribution lines or feeder lines, especially in towns and cities, is normally collected in underground tanks, pumped up by electric pumps into overhead tanks and allowed to flow down to utility points under gravity. This is basically because the pressure with which the water flows into the distribution lines or feeder lines is not sufficiently strong enough to lift the water directly into the overhead tanks located at heights meters above the ground level. The energy in the water getting collected in the underground tank is thus wasted without any work being done. Electric pumps consume electrical energy for their operation and require periodic maintenance. Also if there is a breakdown of the electric pumps, water cannot be pumped up into the overhead tanks until the pumps are repaired. This disrupts temporarily water supply to the utility points causing a lot of inconvenience and hardship to the users.
Air operated double diaphragm pumps used for pumping fluids require air for their operation. A typical air operated double diaphragm pump comprises two liquid chambers and two flexible diaphragms each located in each of the chambers. The diaphragms are connected at each end of a diaphragm shaft with back plates. A pilot valve spool is pushed back and forth whenever the diaphragm shaft reaches its limit. The pilot
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valve spool diverts the air flow into the diaphragms through distribution valves which are free floating non-return valves operated by pressure difference in the liquid chambers. The liquid chambers are alternatively filled and emptied by drawing fluid in through an inlet manifold and by allowing fluid to flow out through an outlet manifold. Pump speed, fluid discharge and discharge pressure are controlled by decreasing or increasing the flow of air into the diaphragms. Diaphragm pumps are complicated in construction and difficult to operate. They are also expensive. Requirement of air also increases the cost of operation of diaphragm pumps. Also in a given construction of the diaphragm pumps, the output pressure is fixed and cannot be varied.
OBJECTS OF INVENTION
An object of the invention is to provide a self driven bellow type water pump which does not require any external energy input for its operation and is simple in construction and easy to operate.
Another object of the invention is to provide a self driven bellow type water pump, whose output pressure can be varied in a given construction of the pump.
Another object of the invention is to provide a self driven bellow type water pump, which can be used as a booster or auxiliary pump to an electric pump so as to reduce the energy consumption of the electric pump and realise savings in cost and to ensure water distribution at utility points in case of breakdown of the electric pump.
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DETAILED DESCRIPTION OF INVENTION
According to the invention there is provided a self driven bellow type water pump located above an underground tank and comprising a housing provided with mounting means for mounting it on the underground tank and partitioned into two chambers by a partition wall, the two chambers each being provided with an outlet port, a piston rod reciprocally disposed in the partition wall and having its ends extending into the chambers, a pair of pistons each fitted at each end of the piston rod and disposed in each of the chambers, a pair of driver bellows, each located in each of the chambers between the respective piston and end wall of the housing, each of the driver bellows being provided with an inlet passage connected to an incoming water supply line through a valve and a pressure responsive outlet valve and a pair of driven elastic bellows, each located in each of the chambers between the respective piston and the partition wall, each of the driven bellows being provided with an inlet line connected to the underground tank through a pressure responsive inlet valve and an outlet line connected to an overhead tank through a non-return valve, the driver bellows each being larger in volume than each of the driven bellows, the volume ratio between the driver bellows and driven bellows being selected to increase the output pressure of the pump, the outlet ports and outlet valves being larger than the inlet passages.
The following is a detailed description of the invention with reference to the accompanying schematic drawings, in which :
Figs 1 and 2 are crosssections of the self driven bellow type water pump according to an embodiment of the invention when the pistons are about to describe the forward and reverse strokes respectively;
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Figs 3 and 4 are enlarged closed and open views of the pressure responsive outlet valve of each of the driver bellows of the pump of Figs 1 and 2;
Figs 5 and 6 are enlarged closed and open views of the pressure responsive inlet valve of each of the driven bellows of the pump of Fig 1 and 2;
Fig 7 is exploded view of the pump of Figs 1 and 2;
Fig 8 is side view of the pump of Figs 1 and 2; and
Fig 9 is a schematic illustration of a typical application of the pump of Figs 1 to 8.
The pump 1 as illustrated in Figs 1 to 8 of the accompanying drawings comprises a cylindrical housing 2 provided with a mounting base 3 having mounting bolt holes 3a therein. The housing is further provided with end covers 4 detachably fitted to it with screws 5. The housing is partitioned into two chambers 6 and 7 by partition wall 8. The chambers are provided with outlet ports 9 and 10, respectively. 11 is a piston rod reciprocally disposed in the partition wall and having its ends extending into the chambers. A pair of pistons 12 and 13 each is detachably fitted at each end of the piston rod and is disposed in each of the cylinders. A pair of annular shaped driver bellows 14 and 15 each is located in each of the chambers between the respective piston and the respective end cover of the housing. Each of the driver bellows is provided with an inlet passage 16 and a pressure responsive outlet valve comprising a
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bent portion 17 and a lip portion 18 adapted to bend or fold over the bent portion (Figs 3 and 4). 19 and 20 are a pair of an annular shaped driven elastic bellows each located in each of the chambers between the respective piston and the partitioned wall. Each of the driven bellows is provided with an inlet line 21 having a pressure responsive inlet valve comprising a flap 22 adapted to close against the mouth of the inlet line (Figs 5 and 6). Each of the driven bellows is also provided with an outlet line 23 having a non-return valve 24. As shown in Fig 9 of the accompanying drawings, the pump of Figs 1 to 8 is located on the underground tank 25 with the outlet ports 9 and 10 connected to the underground tank through lines 26, 27, 28 and 29. The inlet lines 21 of the driven bellows are also connected to the underground tank via lines 30 and 31. The inlet passages 16 of the driver bellows are connected to an incoming water supply line 32 through a valve 33. The outlet lines 23 of the driven bellows are connected to an overhead tank (not shown) through lines 34 and 35. 36 is an electric pump located on the underground tank with the suction line 37 extending into the underground tank and the discharge line 38 connected to the overhead tank. The ground level is marked 39 in Fig 9. The pump of the invention is fitted on the underground tank by bolts (not shown) passing through the bolt holes 3a in the mounting bases and through the top surface of the underground tank. The cyclic operation of the pump is as described below.
During operation of the pump valve 33 in the incoming water supply line 32 is kept opened. At the start of the forward strokes of the pistons ie movement of the pistons in the left hand direction in Fig 1, driver bellow 14 is fully collapsed or contracted and lip 18 is closed against the bent portion 17 thereof ie valve of bellow 14 is closed. Incoming
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water from supply line enters the driver bellow 14 and the driver bellow starts inflating or expanding under the incoming water pressure. Driver bellow 15 is full with water from the supply line and lip 18 is closed against the bent portion 17 thereof. The driven bellow 19 is full with water from the underground tank and valve 22 in bellow 19 is closed ie lip 22 is closed against the mouth of inlet line 21. Driven bellow 20 is collapsed and valve 22 in bellow 20 is open ie flap 22 is moved away from the mouth of inlet line 21 thereof. Due to the expansion of the bellow 14 under the positive pressure of the incoming water the piston 12 moves against driven bellow 19 and compresses or contracts bellow 19. Under the compressive force of piston 12, water in bellow 19 is forced out of bellow 19 into the overhead tank via nonreturn valve 24 and bellow 19 starts collapsing or contracting. As the piston 12 moves in the left hand direction in Fig 1, piston 13 also moves in the left hand direction and describes the forward stroke. As the piston 13 moves in the left hand direction in Fig 1, it compresses driver bellow 15 . Responsive to the water pressure being developed within the bellow 15, the lip 18 moves away from the bent portion 17 ie the valve of bellow 15 opens allowing the water in bellow 15 to drain out into the chamber 7 and from there into the underground tank via outlet port 10. Driven bellow 20 expands creating a vacuum therein. Under the vacuum created in the bellow 20, valve 22 opens and moves away from the mouth of the inlet line 21 and water is sucked into the bellow 20 from the underground tank. As the bellow 20 fully expands or inflates under the pressure of incoming water valve 22 closes against the mouth of the inlet line 21. At the end of the forward strokes of pistons 12 and 13, bellow 14 is fully expanded with water and bellow 15 is fully compressed and emptied. Lip 18 closes against the bent portion 17 and closes the valve of bellow 14. Lip 18 moves away from bent portion 17
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and opens the valve of bellow 15. Bellow 20 is fully expanded with water and valve 22 in bellow 20 is closed against the mouth of the inlet passage 21. Bellow 19 is fully collapsed and valve 22 in bellow 19 is open. The pistons are ready to describe the reverse strokes as shown in Fig 2. During the reverse stroke of the pistons, incoming water in the supply line enters the bellow 15 and develops a positive pressure and starts expanding or inflating the bellow 15. Under the force of expansion of bellow 15, the pistons move in the left hand direction in Fig 2 and describe the reverse strokes. Valve of bellow 14 opens as the lip 18 moves away from the bent portion 17 responsive to development of water pressure within bellow 14 under compression of bellow 14 by piston 12. Water in the bellow 14 flows out into the underground tank via valve of bellow 14 and outlet port 9. As the piston 12 moves in the right hand direction, bellow 19 expands and creates a vacuum within thereby opening valve of bellow 19 as flap 22 of bellow 20 moves away from the mouth of inlet line 21. Water is sucked into the bellow 19 from the underground tank via inlet line 21 and bellow 19 starts expanding until it is full with water. When the bellow 19 is full with water, valve of bellow 19 closes against the mouth of the inlet line 21 under the force of water filled in the bellow 19. As the piston 13 moves in the right hand direction, bellow 15 continues to expand with water getting filled therein. Bellow 20 is compressed by piston 13 and the water in bellow 20 is forced out into the overhead tank under the compressive force exerted by the piston 13. At the end of the reverse strokes of the pistons, bellow 14 is fully compressed by piston 12 and valve of bellow 14 is closed. Bellow 19 is fully expanded with water and valve of bellow 19 is closed. Bellow 20 is fully compressed and valve of bellow 20 is open. Bellow 15 is fully filled with water and valve of bellow 15 is closed as shown in Fig 1. The pump is now
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ready for the next cycle of operation. Thus water flows alternately into the underground tank and into the overhead tank from both bellows 14 and 15 and 19 and 20 respectively so as to ensure continuous supply of water into the underground tank and overhead tank until the inflow of water from supply line lasts. The size of the outlet ports 9 and 10 and outlet valves of the driver bellows is selected to be larger than the size of the inlet passages 16 so as to prevent pressure build up in the driver bellows and ensure emptying of the driver bellows while incoming water is flowing into them.
According to the invention the pump operates under the influence of the pressure of the incoming water from the supply line into the driver bellows 14 and 15 alternately continuously without using any external energy input and fully utilising the pressure available in the incoming water. The pump of the invention is cost effective and simple in construction. The volumes of the driven and driver bellows can be varied by replacing them with bellows of appropriate volumes so as to generate varying pressure output. In order to facilitate replacement of the bellows, the end covers and pistons are preferred to be detachable. Detachable end covers provide access into the housing. Once the incoming of water in the supply line has completely stopped, the water in the underground tank is lifted into the overhead tank by operating the electric pump. The pump of the invention can be effectively used as a booster or auxiliary pump to the electric pump so as to reduce the energy consumption of the electric pump and save cost. Additionally, in case of break down of the electric pump, the pump of the invention will ensure lifting of certain amount of water into the overhead tank so as to ensure water distribution at the utility points alteast for some time until the electric pump is repaired.
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The output pressure of the pump will depend upon the volume ratio between the driver and driven bellows. The output pressure can be increased by selecting the volume ratio of the driver and driven bellows. Using a typical pump comprising driver and driven bellows of volume ratio 2:1 and an incoming water supply of pressure 1.5 kg sq cm, it was possible to generate an output pressure of 3 kg per sq cm. Using an output pressure of 3 kg per sq cm water can be easily lifted to a height of 20 to 25 meters.
The end covers and pistons need not be detachable. The housing can be square, rectangular or elliptical in shape besides being circular. The mounting means may be of a different construction or configuration. The mounting means is optional and the pump can remain in position without the mounting means under its own weight. The objective of the invention is essentially to make effective use of the energy available in the incoming water. Instead of water, other liquids or fluids can also be used for driving the pump of the invention. Essentially the device is for increasing the pressure output. Instead of lifting the water into overhead tanks, it can also be used for lifting the water to a higher level or driving a load like actuators. Such variations of the invention are to be construed and understood to be within the scope of the invention.
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We claim :
1. A self driven bellow type water pump located above an underground tank and comprising a housing provided with mounting means for mounting it on the underground tank and partitioned into two chambers by a partition wall, the two chambers each being provided with an outlet port, a piston rod reciprocally disposed in the partition wall and having its ends extending into the chambers, a pair of pistons each fitted at each end of the piston rod and disposed in each of the chambers, a pair of driver bellows, each located in each of the chambers between the respective piston and end wall of the housing, each of the driver bellows being provided with an inlet passage connected to an incoming water supply line through a valve and a pressure responsive outlet valve and a pair of driven elastic bellows, each located in each of the chambers between the respective piston and the partition wall, each of the driven bellows being provided with an inlet line connected to the underground tank through a pressure responsive inlet valve and an outlet line connected to an overhead tank through a non-return valve, the driver bellows each being larger in volume than each of the driven bellows, the volume ratio between the driver bellows and driven bellows being selected to increase the output pressure of the pump, the outlet ports and outlet valves being larger than the inlet passages.
2. A water pump as claimed in claim 1, wherein the pressure responsive outlet valve comprises a bent portion and a lip portion adapted to bend over the bent portion and the pressure responsive inlet valve comprises a flap adapted to close against the mouth of the inlet line.
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3. A water pump as claimed in claim 1 or 2, wherein the driver bellows and the driven bellows are annular shaped.
4. A water pump as claimed in anyone of claims 1 to 3, wherein the end walls of the housing comprises detachable end covers.
5. A water pump as claimed in anyone of claims 1 to 4, wherein the housing is circular, square, rectangular or elliptical shaped.
6. A water pump as claimed in anyone of claims 1 to 5, wherein the pistons are detachably fitted to the piston rod ends.
Dated this 29th day of March 2007
(Jose MA)
of Khaitan & Co
Agent for the Applicants
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ABSTRACT
A self driven bellow type water pump (1) located above an underground tank. The pump comprises a housing (2) provided with mounting means (3) for mounting it on the underground tank and partitioned into two chambers (6, 7) by a partition wall (8). The two chambers each is provided with an outlet port (9, 10). A piston rod (11) is reciprocally disposed in the partition wall and has its ends extending into the chambers. A pair of pistons (12, 13) each is fitted at each end of the piston rod and is disposed in each of the chambers. A pair of driver bellows (14, 15) each is located in each of the chambers between the respective piston and end wall of the housing. Each of the driver bellows is provided with an inlet passage (16) connected to an incoming water supply line (32) through a valve and a pressure responsive outlet valve (17, 18). A pair of driven elastic bellows (19, 20) each is located in each of the chambers between the respective piston and the partition wall. Each of the driven bellows is provided with an inlet line (21) connected to the underground tank through a pressure responsive inlet valve (22) and an outlet line (23) connected to an overhead tank through a non-return valve (24). The driver bellows each is larger in volume than each of the driven bellows. The volume ratio between the driver bellows and driven bellows is selected to increase the output pressure of the pump. The outlet ports and outlet valves are larger than the inlet passages (Fig 1).