Water treatment device

Abstract: A water treatment device (10), comprising a replaceable filter cartridge (40), flow totalization means for mechanically totaling the volume of water that has been filtered through said replaceable filter cartridge (130), and means, cooperating with said flow totalization means, for indicating end of life of said replaceable filter cartridge (150, 140), mechanical means for resetting said flow totalization means to a zero volume position (160), including a member (53) of said filter cartridge which automatically reset s (ting) said flow totalization means upon replacement of said filter cartridge (53).

Description: Field of the Invention This invention relates generally to water treatment devices, and more particularly to devices incorporating mechanisms for end-of-life indication, automatic shutoff and resetting the automatic shutoff. Background of the Invention Water treatment devices for home and other use are well known in the art. Such devices are incorporated into a water system either in-line or at a terminal end. An example of the former would be an under-the-counter device which filters water prior to reaching the faucet. There are two common types of terminal end devices--countertop and faucet-mounted. As compared to countertop and under-the-sink devices, designing a faucet-mounted device presents special challenges. These include making the device sufficiently light so that it can be attached to a faucet and sufficiently compact so that the device does not take up valuable sink space. Water treatment devices can treat water by the use of mechanical filtration or chemical treatment. Mechanical filters treat water by preventing passage of particulates. As a mechanical filter approaches the end of its useful life, reduced or stopped flow due to particulate accumulation provides a ready indication that element replacement is necessary. By contrast, when the capacity of a chemical element is exceeded, there is no such indication. Chemical treatment is accomplished by processes such as adsorption (e.g. charcoal media) and ion exchange (e.g. for lead removal). Such chemical treatment eventually degrades and becomes inactive. However, no indication is provided to the user that the water is no longer being treated by the media. As a result, various approaches have been taken to indicate end of life to the user where it is not inherently provided by the behavior of the filter media. One example is shown in U.S.-A-4,686,037. In this approach, a pre-filter is used to entrap contaminants, and the color of the pre-filter is compared by the user with a reference strip to determine when the media requires replacement. The problem with this approach, however, is that it is inherently subjective, and therefore subject to error. Also, the user can easily forget to check the reference filter and mistakenly believe the media is still purifying when it is not. A much more accurate and foolproof means of indicating end of life is through totalizing the volume which has passed through the media and automatically shutting off flow after a predetermined volume has passed through the device. Although the flow totalization and shutoff valve mechanisms required are relatively expensive and complex, this has become recognized as the most accurate means of indicating end of life. For example, the certifying agency in the United States for water treatment devices, the National Sanitation Foundation, requires for certification of a rated volume, twice the filter media capacity when an automatic shutoff is not used, and only 20% additional capacity when an automatic shutoff is employed. Both electrical and mechanical approaches to flow totalization are known in the prior art. Examples of the former are shown in U.S.-A-4,918,426 and 5,089,144 and in JP-A-04094708 which discloses a water treatment device comprising a replaceable cartridge ; a flow totalization timer circuit ; end-of-life indicating means ; and mechanical resetting means including a cartridge member (bottom cartridge surface) for automatically resetting the flow totalization means to a zero volume position upon exchanging the cartridge. In this approach, flow rate is measured by, for example, a pressure transducer and then integrated to calculate total volume. After a predetermined volume has been reached, a valve is electrically actuated to stop flow. Examples of mechanical totalization in water treatment devices are shown in U.S.-A-4, 681, 677 and 4, 698, 164. In the mechanical approach, typically a turbine powered by water flowing through the device is interconnected with a series of gears which mechanically "add up" the volume of water which has passed through the device. In turn, the gearing mechanism is interconnected with a valve such that, after a predetermined volume of water has passed through the device, the valve is mechanically actuated to stop flow through the device. US-A-4769135 discloses a device comprising a replaceable filter cartridge, mechanical flow totalization means, and shut off valve means to interrupt the flow after a predetermined volume of water has passed, in which the resetting flow totalization means to a zero volume position is achieved by replacing a frangible link. However, prior art mechanical automatic shutoff mechanism suffer from certain shortcomings. One problem is that the mechanisms employed, such as in the '677 patent, are too bulky to be included in a compact device. Another problem with prior art devices is that they make resetting the totalization and shutoff mechanism unnecessarily difficult and/or expensive. For example, to reset the device shown in the '677 patent, one would apparently have to manually release the valve from the rotating cam and manually disengage the gearing mechanism to reset the totalization mechanism to a zero volume position. In the '164 patent, the valve shutoff mechanism is incorporated into the replaceable cartridge, and the shutoff valve is connected to the gearing mechanism upon replacement of the cartridge. This approach is unnecessarily wasteful and expensive because the shutoff valve is thrown away with each cartridge, rather than being reused. With respect to faucet-mounted water treatment devices, it is not known in the prior art to incorporate automatic shutoff end-of-life indication. This is due at least in part to the obstacles associated with incorporating a mechanical flow totalization and shutoff mechanism in the required compact size. As a result, prior art devices have employed much cruder forms of end-of-life indication, such as that discussed above in the '037 patent. Not only are prior art end-of-life indicating devices much less accurate, but they are also unnecessarily wasteful due to the more frequent cartridge replacement often required by certification standards. A feature that is common to faucet-mounted devices is the ability to bypass or divert water from the filter media so that untreated water can be obtained from the faucet. This is desirable because it avoids unnecessary use of the filter media, allowing the user to bypass the water treatment device if the water is not intended for drinking, as for example for washing hands or dishes. Such a bypass mechanism is shown in the 037 patent. In this approach, a separate handle is attached to the opposite end of the mounting member to control a bypass valve. Other prior art devices use this same approach, and therefore suffer from certain disadvantages. The separate handle adds unnecessary complexity and expense to manufacturing a bypass mechanism. Also, because of the environment in which faucet-mounted devices are employed, there is a significant problem with keeping such devices clean. A separate handle only makes this more difficult, adding increased surface area and creating difficult-to-clean crevices. Finally, the added handle makes the appearance of the device less appealing, which is a particularly important concern for faucet-mounted devices. What has been needed is a compact, low-cost and easy-to-manufacture water treatment device having an automatic shutoff mechanism which is easy to reset. Summary of the Invention According to the present invention, a water treatment device having a replaceable filter cartridge is provided. The filter cartridge can include mechanical or chemical filter media or a combination thereof. In one aspect of the invention, the water treatment device includes an arrangement comprising a mechanism for mechanically totalling the volume of water that has been filtered and a mechanism for indicating when the replaceable filter cartridge has reached the end of its useful life. End of life indication is provided by a valve mechanism for stopping flow after a predetermined volume has been filtered. The arrangement also comprises a mechanism for resetting the flow totalization mechanism, including a spring. The spring is connected with and biased by the flow totalization mechanism, and a mechanism for releasing the spring to reset the flow totalization mechanism is included. The spring can be any of a variety of mechanical springs which would be suitable for this purpose, including for example torsional, coil, leaf, and helical springs in either compression or tension. These and other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto. However, for a better understanding of the invention and its advantages, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter in which there is illustrated and described a preferred embodiment of the invention. Brief Description of the Figures Figure 1 is an exploded perspective view of a water treatment device according to the present invention; Figure 2 is a cross-sectional view of the water treatment device shown in Figure 1 as viewed generally from Section 2-2 of Figure 4; Figure 3 is a partial cross-sectional view of the water treatment device shown in Figure 1 as viewed from Section 3-3 of Figure 5; Figure 4 is a top partial cross-sectional view of the flow shutoff mechanism of the present invention, with the mechanism in the zero volume position; Figure 5 is a top partial cross-sectional view of the flow shutoff mechanism of the present invention, with the flow shutoff mechanism at the end-of-life position; Figure 6 is a top partial cross-sectional view of the flow shutoff mechanism of the present invention, with the flow shutoff mechanism in an intermediate position and the reset mechanism of the present invention activated; Figure 7 is a cross-sectional view of a bypass mechanism according to the present invention, with the flow diverted through the mounting member; and Figure 8 is an end cross-sectional view of the flow-bypass mechanism shown in Figure 7 as viewed from Section 8-8 of Figure 7. Detailed Description of the Preferred Embodiment Referring now to the drawings wherein like numerals designate like parts, a faucet-mounted water treatment device 10 is shown in Figures 1-8. Although water treatment device 10 is faucet mounted, many of the novel features disclosed herein can be incorporated into in-line or countertop devices as well. Referring to Figures 1 and 2, water treatment device 10 includes housing 20 which comprises upper portion 22 and cap 24 which threads into upper portion 22. First O-ring 26 is provided in channel 28 to create a watertight seal between upper portion 22 and cap 24. Replaceable filter cartridge 40 is inserted into upper portion 22 from below, and cap 24 is threaded to upper portion 22 to secure cartridge 40 in housing 20. Water flows through housing 20 and cartridge 40 as follows. Water enters housing 20 from valve body 30 at inlet opening 21 and fills annular space 60 between cartridge 40 and housing 20, including peripheral annular channel 62 formed in top 52 of cartridge 40. As best shown in Figures 1 and 3, water then flows from channel 62, into notch 64 of top 52 and up through cylindrical portions 72, 82 of lower 70 and upper 80 plates, respectively. water is then directed out of jet 92 of top plate 90 (best shown in Figure 1) to turn blades 102 of turbine 100. Turbine 100 is tightly nested in top plate 90, as best shown in Figure 2, with minimum clearance between blades 102 and top plate 90 to maximize turbine efficiency. Water exits turbine 100 and passes through exit cylinder 94 of top plate 90, which extends over second cylindrical portion 84 of upper plate 80. In normals operation (i.e. when flow has not been "shut off"), water then flows into cartridge 40 through inlet opening 66 in top 52. While water primarily flows as described due to the arrangement of the various parts, it should be understood that water also fills chamber 68 generally defined between lower plate 70 up to upper portion 22 of housing 20. Water flows through cartridge 40 by passing through filter disc 43, second screen 55, first media 42, first screen 54, second media 44, and post filter 56, respectively, and then out through holes 49 in retainer 48. Water then exits housing 20 from outlet opening 29. It will be understood that outlet opening 29 could take on various configurations and could be from various positions in housing 20, although it is preferable that opening 29 be from bottom of housing 20. Water treatment device 10 includes an arrangement 15 for indicating the useful life remaining in replaceable filter cartridge 40. Arrangement 15 includes flow totalization mechanism 130 and shutoff valve mechanism 150. It will be understood by those skilled in the art that a variety of totalization 130 and valve 150 mechanisms could be employed within the scope of the present invention to achieve the same purpose. Arrangement 15 also includes reset mechanism 160 for resetting totalization 130 and valve 150 mechanisms. The reset mechanism 160 includes biased spring 162 which is released by insertion of cartridge 40. In the preferred totalization mechanism 130, turbine 100 is connected with a plurality of gears 132 which in turn are connected with a rotating sector 140. It will be understood that turbine 100 need not be directly connected to first gear 134 and that sector 140 need not be directly connected to last gear 136. Gears 132 are successively interconnected, with each having a 10-to-1 ratio in the preferred embodiment. Turbine 100 and two gears 132 are stacked on first pin 138, and the remaining three gears 132, including first 134 and last 136 gears are stacked on second pin 139. Pins 138, 139 are held in place from above by upper portion 22 of housing 20. From below, first pin 138 is inserted into a hole in upper plate 80, and second pin 139 is held in place by last gear 136, which extends through and is seated on raised portion 86 of upper plate 80. Last gear 136 is connected to sector 140 by pinion 137 of last gear 136 engaging teeth 142 of sector 140, as best shown in Figures 4 and 5. Thus, as turbine 100 rotates, gears 132 are successively rotated, causing sector 140 to be rotated by pinion 137 and thereby "adding up" the volume of water that has passed through cartridge 40. The preferred shutoff valve mechanism 150 includes ball 152, which is held by and rotated with sector 140, and flow inlet opening 66 of filter cartridge 40. Shutoff mechanism 150 starts in a zero volume position, as shown in Figures 2 and 4. After totalization mechanism 130 has rotated sector 140 to the flow stop position, as shown in Figures 3 and 5, ball 152 becomes seated in inlet opening 66 of cartridge 40, which is formed by raised portion 51 of top 52 extending through lower plate 70. It will be understood by those skilled in the art that a variety of other suitable mechanical valve mechanisms could also be employed. Reset mechanism 160 includes spring 162 which is connected to and wound by sector 140 as sector 140 rotates. It will be understood that, while the preferred embodiment employs a wound coil spring 162, numerous other types of springs as discussed hereinabove and a variety of other arrangements and connections could be employed whereby a spring is biased by a flow totalization mechanism. To release spring 162 in the preferred embodiment, pinion 137 is radially disengaged from teeth 142 of sector 140, thereby causing sector 140 to be rotated back to the zero volume position by spring 162, as shown in Figure 6. It will be understood that teeth 142 and pinion 137 could also be separated axially to achieve the same result. In the preferred embodiment, spring 162 is released by a transverse movement of slide 164 acting as a release arm. Slide 164 includes vertical extension 165 onto which sector 140 and spring 162 are rotatably mounted. Spring 162 includes levers 163 extending from opposite ends, with one of levers 163 abutting stop 144 on sector 140 and the other lever 163 abutting fixed stop 74 on lower plate 70. This arrangement allows spring 162 to serve both the functions of resetting sector 140 and returning slide 164 to its unslid position because spring 162 resists torsional movement of sector 140 as well as transverse movement of slide 164. Slide 164 is held in line by guides 76 on lower plate 70. The components between upper 80 and lower 70 plates are held together by screws 88 inserted from below, as shown in Figure 1. In the preferred embodiment, slide 164 is slid by insertion and removal of filter cartridge 40. In the preferred arrangement, slide 164 is slid by cam 53 extending axially from top 52 of cartridge 40. When cartridge 40 is axially inserted into housing 20, cam extends through opening 78 in lower plate 70 and abuts cam follower surface 166 on slide 164 to move slide 164 transversely. In addition to providing a flow stop indication of end of life, a continuous visual indication of the amount of useful life remaining in replaceable filter cartridge 40 is provided in the preferred embodiment. This is accomplished by colored screen 146 at the end of sector 140, which is visible trough lens 170 as sector 140 rotates. Referring to Figure 1, lens 170 is inserted into slot 23 of upper portion 22 of housing 20, and is sealed by gasket 171. In the preferred embodiment, cartridge 40 comprises two chemical filter media, including first media 42, which comprises an ion exchange resin suitable for removing lead, and second media 44, which comprises Granular Activated Charcoal ("GAC"). Mechanical or other chemical filter media can also be employed within the scope of the invention in various numbers or combinations. In the preferred cartridge 40, media 42, 44 are enclosed by base 46, O-ring retainer 48 which is friction fit with an inwardly extending cylindrical portion 50 of base 46, and top 52 which is friction fit with an inner side of the upper portion of base 46. Base 46 includes shoulder 47 which is supported by cap 24 to push cartridge 40 upwardly into housing 20. Retainer 48 holds second O-ring 27 in place to create a seal between retainer 48, cylindrical portion 50 and inward extension 25 of cap 24. Water exits cartridge 40 through holes 49 in retainer 48. Within cartridge 40, filter media 42, 44 (not shown in Figure 1) are separated by first screen 54, and second screen 55 separates first media 42 from filter disc 43 which is held between top 52 and second screen 55. Filter disc 43 is made of white filter paper and is for the purpose of providing the user with a visual reference to assure the user that cartridge 40 is performing its function and to indicate whether a particular cartridge has been used. In the preferred embodiment, top 52 is clear so that the user can see if disc 43 has gathered contaminants, indicating that the cartridge 40 has been used. U-shaped post filter 56 extends over cylindrical portion 50 to prevent GAC from being flushed out, and post filter cap 57 extends over filter 56 to direct the flow of water to bottom of cartridge 46 to assure that the entire second media 44 is utilized. It should be understood that the present invention is not limited to the preferred embodiment discussed above, which is illustrative only.

Claims: A water treatment device (10), comprising: (a) a replaceable filter cartridge (40); (b) flow totalization means for totaling the volume of water that has been filtered through said replaceable filter cartridge (130); (c) means, cooperating with said flow totalization means, for indicating end of life of said replaceable filter cartridge (150, 140); (d) mechanical means for resetting said flow totalization means to a zero volume position (160), including a member (53) of said filter cartridge which automatically resets said flow totalization means upon replacement of said filter cartridge (53), characterized in that said flow totalization means are means which mechanically total the volume of water and in that said reset means includes a spring (162) interconnected with and biased by said flow totalization means such that, when said cartridge is replaced, said spring is released to reset said flow totalization means, said member being a cam (53) extending from said replaceable filter cartridge such that said spring is released by said cam to reset said flow totalization means upon replacement of said cartridge. A water filter cartridge (40) for use in a water device (10) having a mechanical totalization mechanism (130), and a flow totalization reset mechanism (160), the water filter cartridge comprising: (a) an outer shell (46, 52) containing water treatment material (42, 44) and having a central axis; (b) an inlet opening (66) proximate a first end and an outlet opening (40) proximate a second end of said outer shell ; characterized by (c) a cam (53) extending axially from said first end of said outer shell, said cam being constructed and arranged such that, when the filter cartridge is inserted into or withdrawn from the water treatment device substantially along said central axis, said cam mechanically actuates resetting of the mechanical flow totalization mechanism. A water filter cartridge as defined in claim 2, wherein said cam (53) includes a double sloping facade facing generally radially inward toward said central axis, said facade actuating said flow totalization reset mechanism upon axial insertion or withdrawal of said filter cartridge. A water filter cartridge as defined in claim 3, wherein said shell includes a separate top (52) which defines said first end and includes said inlet opening and said axially extending cam. A water filter cartridge as defined in claim 4, wherein said cam (53) and said inlet opening (66) are radially displaced from said central axis along respective radial lines and said radial lines are approximately 90° apart relative to one another.

Inventors: HEMBREE RICHARD D, SULLIVAN BRIAN F, HEMBREE, M. RICHARD D., SULLIVAN, BRIAN F.
Applicants: PUR WATER PURIFICATION PROD, PUR WATER PURIFICATION PRODUCTS, INC.
Application year: 1995
Main classification: B01D35
IPC codes: C02F1, B01D35