WO2015192968A1

WO2015192968A1 - A metering device for an auto-shut off assembly

Info

Publication number: WO2015192968A1
Application number: PCT/EP2015/001245
Authority: WO
Inventors: Anil HANKARE; Vasanthan Mani; Suresh Kumar Natarajan
Original assignee: Unilever N.V.; Unilever Plc; Conopco, Inc., D/B/A Unilever
Priority date: 2014-06-20
Filing date: 2015-06-19
Publication date: 2015-12-23
Also published as: EA201790050A1; CN106458640A; PH12016502451A1; EP3158299A1; BR112016029257A2; MX2016016535A

Abstract

The present invention relates to a metering device for an auto-shut off assembly to meter the volume of liquid collected in a chamber and capable of determining the end of life of a filter and causing auto shut-off after the calibrated life of the filter. The present invention is particularly useful in water purifiers. The metering device comprises a float, rack and pinion assembly, ratchet and pawl assembly and a screw with an actuator.

Description

A metering device for an auto-shut off assembly Field of the invention The present invention relates to a metering device for an auto-shut off assembly to meter the volume of liquid collected in a chamber. In particular the present invention relates to a metering device for an auto-shut off assembly that is capable of metering volume of water passed through and also determining the end of life of a filter in a water purifier and causing auto shut-off after the calibrated life of the filter is over.

Background of the invention

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field;

Many people in the world live in countries where there is a severe shortage of hygienic potable water. People in these areas have to depend directly on ground water sources like wells, ponds and rivers. Often these water sources are contaminated by sewage, industrial effluents and agricultural byproducts. These areas are generally small villages that do not have municipal drinking water treatment plants. Hence these people have to treat the water themselves before consuming it. The water from these sources are often collected by the people in buckets or pots in small quantities like ten to twenty litres for potable consumption for a day!s use. The most common method to produce dean water is boiling.

There are various ways of purifying water which may be by the use of gravity fed devices or others like the use of reverse osmosis, ultra-filtration, UV based and many others known in the art. Basically in all these there is a mechanism to remove suspended and dissolved impurities and also make the water microbiologically safe.

Use of different types of filters to remove microbiological impurities is known. These filters have a definite life based on a certain water quality and after the end of life is achieved, the filter will have to be replaced. If the filters are not replaced on time it is potentially dangerous as the consumers will be under the false impression that the water that they are consuming is safe and reliable whereas it may be impure water. Hence there is a need for an automatic mechanism that ensures that the water does not flow once the life of the filter is exhausted.

The life of the filter is dependent on the number of liters of water passed thorugh the same and recording the literage will enable determining the life of the filter. In addition to ,that in order that the consumer does not continue to use the filter after the life of the filter is over and pre-determined volume of water has flown through the filter, it will be highly beneficial to have an auto-shut off mechanism. This will ensure that no impure water is consumed by the consumer.

One of the accurate means of indicating end of life of conventional treatment units is through devices which use a process known as "flow totalization." These devices generally do not have an automatic shutoff mechanism.

US4698164 (Kinetico INC, 1987), discloses a filtering apparatus including a fluid monitoring head and a replaceable filter cartridge removably fastened to said head. The cartridge includes a shut off mechanism for interrupting fluid flow through the cartridge when a predetermined quantity of fluid has been treated by the filter. The fluid monitoring head is releasably coupled to the shutoff mechanism when the filter is installed. The shutoff mechanism includes a valve element threadedly carried by a shaft that forms part of a driven member, operatively connected to a drive member forming part of the monitoring head. As the driven member rotates, the valve element is gradually unthreaded until it separates and is driven to a flow interrupting position by a biasing spring. The coupling between the drive and driven members includes apertures on one of the members which are engaged by resilient tongues formed on the other member. US5928504 (Recovery Engineering, 1999), discloses a faucet-mounted water treatment device including a flow totalizer and an end-of-life indicator cooperating with the totalizer to tell the user when it is necessary to replace the filter cartridge. End-of-life indication is provided by a valve which stops flow after a predetermined volume has been filtered and by a rotating screen which shows the amount of useful life remaining in the filter cartridge.

US5873995 (Clorox Co., 1999) discloses an end-of-life indicator comprising a housing having a chamber therein and attachable to the water treatment device, a diaphragm disposed within the chamber, a rotatable cap having indicia disposed thereon adapted to cooperate with the housing, a spring device for rotating the cap with respect to the housing, an escapement device for regulating the rotational displacement of the cap and means for resetting the cap to a start position. The chamber is arranged for the ingress of water into the water treatment device to pressurize the chamber and the egress of water from the water treatment device to depressurize the chamber, the ingress and egress of water defining one fill cycle. The diaphragm is arranged to be moved by the pressurizing and depressurizing of the chamber. The escapement device are arranged to cooperate with the diaphragm and the spring device whereby predetermined incremental rotation of the cap is provided during each of the fill cycles. EP1 138235 (Moulinex, 1922), discloses a electric appliance with a removable cartridge for treating water with an indicating unit that gives indication that the cartridge needs changing when the movable part reaches a predetermined position. This also functions on a float, rachet and pawl assembly mechanism but only has an indicator means to show when the cartridge needs replacement which can possibly be ignored by a user and does not have an auto-shut off mechanism that prevents the user from consuming unpurified water that can flow even after the end of life of the filter cartridge is reached.

W09615994 (Recovery Engineering, 1996), discloses a water treatment having a purifying cartridge with an end of life mechanism. The apparatus comprises a housing with at least one opening for the passage of liquid to a chamber, formed by the interior of the housing and the water treatment unit. The chamber includes a support member mounted to the housing. A float is rotationally mounted on the support member. The support member limits float movement to a predetermined distance upon each rotation of the float, resulting from each cycle (use) of the water treatment unit. Once the float has made a specific number of rotations and has travelled the complete distance of the support member (as water fills and drains from the chamber), the float rests in a position where it is visible through the opening for the passage of liquid to a chamber in the housing, indicative of the end of life of the water treatment unit.

W09615994 discloses a water flow restriction mechanism but that does not stop the flow of water completely when end of life is reached. This device determines the flow of unpurified water rather than purified water and there will be other problems depending on the quality of water. The end of life indicator will be visible only after the pre-fixed volume of water has flow through and it is not possible to provide a pre-warning of the reaching of the end-of-life.

Most end-of-life and metering mechanisms known in the prior art rely on momentum of flowing water to drive some movable components in an appropriately designed mechanism. However, most of these mechanisms fail to work when water flow rates in the system are very low. This invention aims to overcome this major limitation.

The present inventors have been able to design a metering device for an auto-shut off assembly which is capable of stopping the flow of water after a pre-determined volume of water has collected in a chamber under continuous use. It has also been possible to design a metering device for an auto-shut off assembly which is capable of stopping the flow of water after a pre-determined volume of water has been filtered through a filter.

The present inventors have been able to design a metering device for an auto-shut off assembly which is capable of measuring volume of water and stopping the flow of water when end of life of the filter is reached. The system is a purely mechanical system and runs without electricity and only uses a float principle. The system can measure volume of water flown and also provide an auto shut off even when the device is not in the path of flow of water. The device is particularly capable of accurate metering of the volume of water collected in a chamber even when the flow rate of water into the chamber is extremely low. Summary of the invention

According to the present invention there is provided a metering device for an auto-shut off assembly comprising:

a. Float (1 )

b. rack (2) and pinion (3) assembly

c. ratchet (4) and pawl (5) assembly

d. a screw (7) and an actuator (8) with an internal thread mating with the external thread of the screw wherein the float (1 ) is attached to the proximal end of the rack (2) and reciprocating movement of the float results in reciprocating movement of the rack; wherein the rack (2) engages with the pinion (3) that is rotatably mounted on a shaft (6);

wherein the pawls (5) are mounted on the pinion (3) that engages with the rachet (4) that is fixed on the shaft (6) such that rotational movement of the pinion is transferred to the shaft (6) in one rotational direction only; and

whereby the shaft (6) is connected to the screw (7) optionally via a gear train, such that rotational movement of the shaft results in rotational movement of the screw causing the linear movement of the actuator (8).

According to another aspect of the present invention there is provided a gravity fed water purification device comprising

i. a top chamber for receiving water to be purified and a bottom storage chamber for collecting purified water;

ii. a filter which is in fluid communication between the top and bottom storage chamber;

iii. a metering device for an auto-shut off assembly as claimed in claim 1 and wherein the float of the metering device for an auto-shut off assembly is positioned in the bottom storage chamber. According to yet another aspect of the present invention there is provided a method of determining the volume of water collected in a storage chamber of a water purification device as defined above comprising: i. calibrating the metering device for an auto-shut off assembly as

claimed in claim 1 to correspond to the life of the filter means;

ii. allowing the water exiting the filter to collect in the storage chamber; iii. co-ordinating the movement of the float in the storage chamber to cause the reciprocating movement of the rack;

iv. enabling the rotation of the shaft through the rotation of the pinion; and

v. causing the linear movement of the actuator to close the inlet or outlet of the filter.

The features and advantages of the invention will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples, embodiment and figures given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se.

Detailed description of the invention The invention relates to a metering device for an auto-shut off assembly that is capable of metering the volume of water and also capable of bringing about an auto-shutoff of the of the source of water that gets dispensed into the storage chamber.

The metering device for an auto-shut off assembly basically comprises:

a. Float (1 )

b. rack (2) and pinion (3) assembly

c. ratchet (4) and pawl (5) assembly d. a screw (7) and an actuator (8) with an internal thread mating with the external thread of the screw

wherein the float (1 ) is attached to the proximal end of the rack (2) and reciprocating movement of the float results in reciprocating movement of the rack;

wherein the rack (2) engages with the pinion (3) that is rotatably mounted on a shaft (6); wherein the pawls (5) are mounted on the pinion that engages with the rachet (4) that is fixed on the shaft (6) such that rotational movement of the pinion is transferred to the shaft in one rotational direction only; and

whereby the shaft is connected to the screw (7) optionally via a gear train, such that rotational movement of the shaft results in rotational movement of the screw causing the linear movement of the actuator (8). .

Float:

It is preferable that the float is positioned in a water storage chamber and is in contact with the water during the metering period. It is preferred that the float is as close as possible to the floor of the water storage chamber and more preferably in contact with the floor so that the float preferably comes in contact with water even after the first collection of the water in the storage chamber. The float preferably is made of materials selected from acrylonitrile butadiene styrene, high impact polystyrene, general purpose polystyrene, polypropylene copolymer, poly propylene, Poly carbonate, polyethylene, polyoxymethylene or any other suitable material.

Rack and Pinion:

The float and the rack preferably have a vertical reciprocating movement in the storage chamber as the water level alters in the storage chamber. The pitch of the rack is preferably varied depending on the size of the water purifier and the pitch is preferably determined by the volume of water to be metered. The rack and pinion is made of preferably materials selected from acrylonitrile butadiene styrene, poly carbonate, polyoxymethylene, nylon or any other suitable material.

Gears:

The metering device for an auto-shutoff assembly preferably comprises a gear train between the shaft and the screw that causes the linear movement of the actuator. The gear train preferably comprises at least one spur gear or a bevel gear assembly and in a preferred embodiment it is possible to have both spur gear and bevel gear assemblies. It is preferable that in the bevel gear assembly, the first gear of the bevel gear assembly is preferably fixed on the first shaft and the second gear of the bevel gear assembly is fixed to the screw. It is preferable that the first gear and second gear of the bevel gear assembly are in engagement at 90 degrees to each other.

When the gear train is provided and preferably comprises at least one spur gear assembly a second shaft that is parallel to the first shaft is provided. The first spur gear is preferably fixed on the proximal end of the first shaft to enable its engagement with a second spur gear fixed on the second shaft that is parallel to the first shaft.

It is preferable to have more than one spur gear assembly to preferably aid in varying the volume of water that can be metered before the auto shut off is achieved.

The bevel gear assembly is provided preferably to convert the linear movement of the actuator into a vertical movement.

The gears may be made from any suitable material and preferably is made of materials selected from acrylonitrile butadiene styrene, poly carbonate, polyoxymethylene, nylon.

Screw and Actuator:

Preferably the pitch of the screw has a direct correlation with the travel of the actuator. Preferably for a given movement of the rack, the travel of the actuator is decided by the pitch of the screw. The positive movement of the float-rack causes the rotation of the screw, higher the pitch of the screw the corresponding linear travel of the actuator is less. The overall travel of the actuator can preferably be altered by increasing or decreasing the pitch of the screw. It is preferable to attach a dial on the actuator which moves on a linear scale with markings to show litres of water collected in the storage chamber.

The screw and actuator may be made of any suitable material and preferably are made of acrylonitrile butadiene styrene, poly carbonate, polyoxymethylene, nylon. Auto shut off mechanism:

The Auto shut off is preferably triggered after the desired volume of water has been metered and can be achieved by suitably designing the mechanism. It is preferable to use the linear motion of the actuator to shut off the source of water that gets dispensed into the storage chamber and more preferably close the inlet of the storage chamber. It is preferable that based on this mechanism the auto shutoff can be achieved by several configurations.

A preferable auto shutoff mechanism is to use the linear motion of the actuator to trip a spring loaded shut off valve that closes the source of water that gets dispensed into the storage chamber and more preferably closes the inlet of the storage chamber. In a preferred embodiment the spring is compressed and is kept under tension in a housing during the normal flow of water. On the extreme end of the spring a gasket is mounted. As the metering device nears the preset volume, the linear motion of the actuator triggers the tripping of the spring. As the tension from the spring is released, it comes back to its original position shutting the inlet by the gasket and thereby causing the closure of the inlet of the storage chamber. It is preferable to mount the auto shut off assembly in such a way that the actuator can cause the gasket to close the inlet of the storage chamber. In a more preferred embodiment when the metering device for an auto-shut off assembly is provided in a water purification device the gasket can close the water exiting from the filter media or entering in the filtering media or the inlet of the storage chamber which is in fluid communication with the filter media.

Another preferable auto shutoff mechanism is to provide a flexible diaphragm that can be activated by a moving pin enclosed in a housing. As the actuator moves linearly, it comes in contact with the pin and pushes it linearly. This movement of the pin causes the diaphragm to choke the inlet and thus stop the flow of water into the storage chamber. In a more preferred embodiment when the metering device for an auto-shut off assembly is provided in a water purification device the diaphragm can close the water exiting from the filter media or entering in the filtering media or the inlet of the storage chamber which is in fluid communication with the filter media. The metering device for an auto-shut off assembly is preferably connected to a water purifier provided with a filter and storage chamber to collect the purified water, it is preferable to use any of the auto shut off mechanism mentioned above or any other suitably designed mechanisms. It is preferable to have a mechanism where the linear motion of the actuator is used to shut off the flow of water into either the inlet or the outlet of the filter.

•According to another aspect of the present invention there is provided a gravity fed water purification device comprising

ii. filter which is in fluid communication between the top and bottom storage chamber;

iii. a metering device for an auto-shut off assembly as claimed in claim 1 and wherein the float of the metering device for an auto-shut off assembly is positioned in the bottom storage chamber.

According to yet another aspect of the present invention there is provided a method of determining the volume of water collected in a storage chamber of a water purification device as defined above comprising: i. calibrating the metering device for an auto-shut off assembly as claimed in claim 1 to correspond to the life of the filter means;

iv. enabling the rotation of the shaft through the rotation of the pinion; and v. causing the linear movement of the actuator to close the inlet or outlet of the filter.

Preferably the metering device for an auto shut-off assembly of the present invention is suitable for use in a gravity fed water purification device. It is preferable that the float is positioned in a bottom storage chamber and is in contact with the water during the metering period. It is preferred that the float is as close as possible to the floor of the bottom storage chamber and more preferably in contact with the floor so that the float preferably comes in contact with water even after the first collection of the water in the bottom storage chamber.

The filter is preferably a microbiological interception unit capable of removal of microbiological impurities from water. Such microbiological interception unit is preferably a separation based filter or controlled dosage based chemical purifier.

The invention will now be exemplified with the following non-limiting figures.

Brief description of the figures

Figure 1 : Front view of the metering device for an auto-shut off assembly.

Figure 2: Front view of another embodiment of the metering device for an auto-shut off assembly.

Figure 3: Front view of yet another embodiment of the metering device for an auto-shut off assembly.

Detailed description of the figures

Figure 1 shows the front view of the metering device for an auto-shut off assembly that can be designed for a calibrated volume of water passed through the device and can be positioned along with a water storage chamber so as to determine the volume of water collected in the storage chamber. It also can ensure auto shutoff of the source of water that gets dispensed into the storage chamber. It is essential that the float is always in contact with the water in the storage chamber during the metering period. The storage chamber is preferably connected to a water purifier and holds the water that is preferably purified by the water purifier. Float (1 ) is attached to the proximal end of the rack (2) and is in contact with the water in a storage chamber during the metering period. The pinion (3) and the ratchet (4) are coaxially mounted on the proximal end of a shaft (6) and the distal end of the shaft (6) is connected to a screw (7) and an actuator (8) with internal threads that match the threads of the screw.

When the water starts filling in the storage chamber, the level of water rises in the chamber and float (1 ) that is contact with the water in the storage chamber rises and it makes the rack (2) move upwards. The upward movement of the rack (2) rotates the pinion (3) in any one direction. This rotation of the pinion (3) rotates pawl (5) and the ratchet (4) which brings about the rotation of the shaft (6). As the shaft (6) rotates, the screw (7) also rotates along with the shaft (6). When the screw (7) rotates, the actuator (8) gets unscrewed and moves linearly. This linear movement of the actuator is used to trigger an auto shut off.

Figure 2 shows the front view of another embodiment of the metering device for an auto- shut off assembly.

To the metering device for an auto-shut off assembly as shown in figure 1 at least one spur gear assembly is attached and this enables designing of the metering device for a higher volume of water but using the same dimensions of the rest of the parts of the device. Float (1 ) is attached to the proximal end of the rack (2) and is in contact with the water in a storage chamber. The pinion (3) and the ratchet (4) are coaxially mounted on the proximal end of a shaft (6). A spur gear assembly (9) is provided and the first spur gear (9a) is fixed on the proximal end of the first shaft (6) that engages with a second spur gear (9b) fixed to a second shaft (10) that is parallel to the first shaft (6). The other end of the shaft (10) is connected to a screw (7) and an actuator (8).

When the water starts filling in the storage chamber, the level of water rises in the chamber and float (1 ) that is contact with the water in the storage chamber rises and it makes the rack (2) move upwards. The upward movement of the rack (2) rotates the pinion (3) in any one direction. This rotation of the pinion (3) rotates pawl (5) and the ratchet (4) and brings about the rotation of the shaft (6). The rotation of the shaft (6) enables the rotation of the spur gears (9a) and (9b) of spur gear assembly (9). The rotation of the spur gear (9b) makes the shaft (10) to rotate along with the screw (7). When the screw (7) rotates, the actuator (8) gets unscrewed and moves linearly. This linear movement of the actuator is used to trigger an auto shut off.

Figure 3 shows the front view of yet another embodiment of the metering device for an auto-shut off assembly.

To the metering device for an auto-shut off assembly as shown in figure 1 at least one bevel gear assembly (1 1 ) is attached and this enables the actuator (8) to move in a vertical direction but using the same dimensions of the rest of the parts of the device. Float (1 ) is attached to the proximal end of the rack (2) and is in contact with the water in a storage chamber. The pinion (3) and the ratchet (4) are coaxially mounted on the proximal end of a shaft (6). The first bevel gear (11 a) is fixed on the proximal end of the first shaft (6). Bevel gear (1 1 a) engages with another bevel gear (1 1 b) in such a way that their axis of rotation is at 90 degrees to each other. The other end of the bevel gear (11 b) is connected to a screw (7) and an actuator (8).

When the water starts filling in the storage chamber, the level of water rises in the chamber and float (1 ) that is contact with the water in the storage chamber rises and it makes the rack (2) move upwards. The upward movement of the rack (2) rotates the pinion (3). This rotation of the pinion (3), rotates pawl (5) and the ratchet (4) along with the shaft (6). As the shaft (6) rotates, bevel gears (11 a) and (1 1 b) rotate. This rotation of the bevel gear (1 1 b) makes the screw (7) to rotate and thereby the actuator (8) gets unscrewed and moves linearly. This movement of the actuator is used to trigger an auto shut off.

Examples

The metering device as shown in Figure 3 was attached to a gravity fed water purifier which comprised of a top chamber to receive impure water to be purified and a bottom storage chamber to receive purified water and between the top and bottom storage chamber a cartridge comprising a chemical purifying agent was positioned. The cartridge comprised of an arm which was capable of closing the outlet to the cartridge which leads to the inlet to the bottom storage chamber. The metering device was positioned ensuring that the float of the metering device was in the bottom storage chamber of the water purifier. The metering device was calibrated to trigger auto shut off after 1000 litres of water was passed through the purifier. As the water flowed through the cartridge of the water purifier, the shaft unscrewed the screw and effecting the forward movement of the actuator. This forward motion of the actuator pushed the arm of the cartridge to close the inlet to the storage chamber and prevented any further flow of water into the storage chamber.

Table 1

The data presented in table 1 show that the auto shut off mechanism gets activated after passing of about 1000 litres of water, as the system was initially calibrated for 1000 litres of water.

Claims

1. A metering device for an auto-shut off assembly comprising:

a. Float (1 )

b. rack (2) and pinion (3) assembly

c. ratchet (4) and pawl (5) assembly

wherein the pawls (5) are mounted on the pinion (3) that engages with the rachet (4) that is fixed on the shaft (6) such that rotational movement of the pinion (3) is transferred to the shaft (6) in one rotational direction only; and

whereby the shaft (6) is connected to the screw (7) optionally via a gear train, such that rotational movement of the shaft (6) results in rotational movement of the screw (7) causing the linear movement of the actuator (8).

2. A metering device for an auto-shut off assembly as claimed in claim 1 wherein the gear train comprises a spur gear and/or a bevel gear assembly.

3. A metering device for an auto-shut off assembly as claimed in claim 1 or claim 2 wherein the gear train comprises at least one spur gear assembly (9) wherein a first spur gear (9a) is fixed on the proximal end of the shaft (6) that engages with a second spur gear (9b) fixed on a second shaft (10) that is parallel to the first shaft (6).

4. A metering device for an auto-shut off assembly as claimed in claim 1 or claim 2 wherein the gear train comprises a bevel gear assembly (1 1) wherein the first gear (1 1 a) of the bevel gear assembly (1 1 ) is fixed on the shaft (6) and the second gear (1 1 b) of the bevel gear assembly is fixed to the screw (7).

5. A metering device for an auto-shut off assembly as claimed in claim 4 wherein the first gear (1 1 a) and second gear (11 b) are in engagement at 90 degrees to each other.

6. An auto-shutoff assembly comprising the metering device as claimed in claim 1 wherein the linear motion of the actuator trips a spring loaded shut off valve or activate a flexible diaphragm by a moving pin that closes the inlet to a storage chamber.

7. A gravity fed water purification device comprising

ii. a filter which is in fluid communication between the top and.bottom storage chamber;

8. A gravity fed water purification device as claimed in claim 7 wherein the float is in contact with the floor of the bottom storage chamber.

9. A gravity fed water purification device as claimed in claim 7 wherein the actuator of the metering device for an auto-shut off assembly plugs the flow of purified water from the purifier means for removal of microbiological impurities.

10. A gravity fed water purification device as claimed in claim 7 wherein the purifier means for removal of microbiological impurities may be selected from a chemical purification cartridge or physical separation device.

11. A method of determining the volume of water collected in a storage chamber of a water purification device as claimed in claim 7 comprising: calibrating the metering device for an auto-shut off assembly as claimed in claim 1 to correspond to the life of the filter;

allowing the water exiting the filter to collect in the storage chamber; co-ordinating the movement of the float in the storage chamber to cause the reciprocating movement of the rack;

enabling the rotation of the shaft through the rotation of the pinion; and

causing the linear movement of the actuator to close the inlet or outlet of the filter.