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Water Filter Patent
 

Water filter with adjustable inlet hose assembly

Water filter abstract

A water filter including an inlet assembly which comprises a prefiltering foam tip. The inlet hose includes an adjustable float and a weight on the end of the hose which allows a given length at the end of the inlet hose to extend below the surface of the water being filtered. The water filter further includes a check valve assembly to relieve pressure buildup inside the pump. A unique lever-action handle, in combination with a rocking piston, allows efficient filtering with few moving parts. The filter components are easily replaceable. The main filter assembly is suspended resiliently at its periphery to provide shock-absorbing characteristics. The filter also includes an adaptor base which allows for a direct connect between the vessel into which water is filter. The water filter also provides a unique method of storing the inlet hose to render the water filter easy to carry and prevent foreign objects and debris from entering into the area of working parts.

Water filter claims

We claim:

1. An inlet assembly in combination with a portable water filter, comprising:

an inlet conduit having a first end and a second end, said first end being connected to a water filter, said second end being adapted to be placed in water to be filtered;

a weight coupled to a second end of said inlet conduit, the weight being adapted to maintain the second end below the surface of the water; and

at least one float slidably coupled to the inlet conduit at a position downstream of the second end, said float maintaining the second end off the bottom of the water source, said float being slidably positioned such that a distance between said float and said second end can be varied, thereby positioning said second end at a preferred position between the top surface of the water and the bottom of the water source from which the water is to be drawn into the conduit.

2. A portable water filter according to claim 1 wherein said inlet conduit is a flexible hose.

3. A portable water filter according to claim 1 wherein the weight is a cage which surrounds the second end of the conduit.

4. The portable water filter of claim 3 including a first filter medium removably retained within said cage, said first filter medium having compressible pore sizes and being easily cleanable by compressing and expanding the pore sizes in clean water.

5. The portable water filter of claim 3 wherein the cage is a coil spring.

6. An inlet assembly in combination with a portable water filter, comprising:

an inlet conduit having a first end and a second end, said first end being connected to a water filter, said second end adapted to be placed in water to be filtered;

weight means for maintaining the second end below a surface of the water; and

at least one float means for maintaining the second end of the inlet conduit off the bottom of the water source, the float means being slidably positioned relative to the weight means such that a distance between said float and said second end can be varied, thereby fixing a depth to which the second end will extend below the surface of the water, wherein the weight means is a weight coupled to a second end of said inlet conduit.

7. An inlet assembly in combination with a portable water filter, comprising:

an inlet conduit having a first end and a second end, said first end being connected to a water filter, said second end being adapted to be placed in water to be filtered;

a weight coupled to the second end of said inlet conduit, the weight being adapted to maintain the second end below the surface of the water; and

at least one float encircling the inlet conduit at a position downstream of the second end, said float maintaining a portion of the inlet conduit at the surface of the water and maintaining the second end off the bottom of the water source, the float being located a given distance from the weight to position the second end at a preferred position between the top surface of the water and the bottom of the water source from which the water is to be drawn into the conduit.

8. A portable water filter according to claim 7 wherein said inlet conduit is a flexible hose.

9. A portable water filter according to claim 7 wherein the weight is a cage which surrounds the second end of the conduit.

10. The portable, water filter of claim 7 including a first filter medium removably retained within a cage, said first filter medium having compressible pore sizes and being easily cleanable by compressing and expanding the pore sizes in clean water.

11. The portable water filter of claim 7 wherein the weight is a cage which surrounds the inlet opening of the conduit, and wherein the cage is a coil spring.

12. An inlet assembly in combination with a portable water filter, comprising:

an inlet conduit having a first end and a second end, said first end being connected to a water filter, said second end adapted to be placed in water to be filtered;

weight means for maintaining the second end below a surface of the water; and

at least one float means for maintaining a portion of the inlet conduit at the surface of the water and for maintaining the second end of the inlet conduit off the bottom of the water source, the float means encircling the inlet conduit and being positioned relative to the weight means to fix a depth to which the second end will extend below the surface of the water.

13. An inlet assembly according to claim 12 wherein the weight means is a weight coupled to the second end of said inlet conduit.

14. An inlet assembly according to claim 12 wherein the conduit comprises a flexible hose and the float means comprises a porous foam piece.

15. An inlet assembly in combination with a portable water filter, comprising:

an inlet conduit having a first end and a second end, said first end being connected to a water filter, said second end being adapted to be placed in water to be filtered;

a weight coupled to the second end of said inlet conduit, the weight being adapted to maintain the second end below a surface of the water; and

at least one float encircling the inlet conduit at a position downstream of the second end, said float maintaining a portion of the inlet conduit at the surface of the water and maintaining the second end off the bottom of the water source, the float being slidably positioned such that a distance between said float and said second end can be varied, thereby positioning said second end at a preferred position between the top surface of the water and the bottom of the water source from which the water is to be drawn into the conduit.

16. A portable water filter according to claim 15 wherein said inlet conduit is a flexible hose.

17. A portable water filter according to claim 15 wherein the weight is a cage which surrounds the second end of the conduit.

18. The portable water filter of claim 15 including a first filter medium removably retained within a cage, said first filter medium having compressible pore sizes and being easily cleanable by compressing and expanding the pore sizes in clean water.

19. The portable water filter of claim 15 wherein the weight is a cage which surrounds the inlet opening of the conduit, and wherein the cage is a coil spring.

20. An inlet assembly in combination with a portable water filter, comprising:

an inlet conduit having a first end and a second end, said first end being connected to a water filter, said second end adapted to be placed in water to be filtered;

weight means for maintaining the second end below a surface of the water; and

at least one float means for maintaining the second end of the inlet conduit off the bottom of the water source, the float means encircling the inlet conduit such that a portion of the inlet conduit is maintained at the surface of the water and being slidably positioned relative to the weight means such that a distance between said float and said second end can be varied, thereby fixing a depth to which the second end will extend below the surface of the water.

21. An inlet assembly according to claim 20 wherein the means for maintaining the second end below the surface of the water comprises a weight coupled to a second end of said inlet conduit.

22. An inlet assembly according to claim 20 wherein the conduit comprises a flexible hose and the float means comprises a porous foam piece.

Water filter description

TECHNICAL FIELD

This patent relates to filters, and more particularly, to portable water filters.

BACKGROUND OF THE INVENTION

The need for filtering water for use, drinking, and consumption to remove impurities has long been recognized. The traditional method of purifying water is, of course, to pass the water through a water treatment facility. Such purified water is, however, often unavailable for persons engaged in international travel and for persons traveling through the back country. Although water may macroscopically appear clean and pure, it may nevertheless contain such impurities as bacteria, pesticides, Giardia and other Protozoa. For backpackers and persons traveling abroad, it is also desirable that the filter be small and easily portable, yet capable of separating such impurities from water drawn from a body of water, such as a lake or stream.

There are, however, several problems associated with traditional portable water filters. One problem relates to the intake of water into the water filter. There may be times when it is desirable to draw water from a body of water at a particular depth where the water is the purest. If, for example, a layer of scum lies on the top of a body of water, it may be desirable to place the opening of the intake hose several inches to several feet below the surface to filter the best quality of water available. This will lengthen the life of the filter and improve ultimately the quality of water obtained. Alternatively, if the most contaminated water resides close to the bottom of a body of water, it may be desirable to adjust the depth of the opening of the intake hose so that it is located close to the surface.

Another problem with respect to the intake of water into the water filter relates to dynamic bodies of water. In rivers and streams, the opening of an inlet hose on the filter may bob up and down in the water and remain, at least momentarily, above the surface of the water which prevents drawing a full stream of water into the intake hose.

Yet another problem associated with typical portable water filters is the large contaminants and objects that are suspended in the body of water from which water is being drawn. Absent a preliminary means for filtering the water before it enters into the intake hose, the valves and pumping mechanism can be damaged and the filter rendered useless in a relatively short period of time. Prescreening is thus desirable where relatively large foreign objects, such as twigs, leaves, heavy sediment or other large-sized objects, may be present in the water to be filtered.

Traditional prefiltering methods involve a variety of types of filters and screens. While these prefilters prevent large obstacles from entering into the intake hose, they are commonly permanently attached to the end of the intake hose and thus require backflushing to clean the prefilter and free it of objects that have become lodged in the filtering pores.

Still another problem associated with traditional portable water filters relates to clogging of the main filter medium within the filter body. Once the main filter medium has become clogged, which is inevitable over the long run, the filtering (usually carried out by some manner of pumping) becomes progressively more difficult. In most pump models, for example, the water discharged from the outlet remains the same for each full stroke of the piston being pumped. The more clogged the filter medium, the more difficult it is to pump. This increased difficulty of filtering water requires more effort for each pumping stroke, which also increases the strain on the parts and the operator. This pressure build-up within the filter also places additional stress on the mechanical parts, which can lead to failure of these parts.

Relief valves have heretofore been looked upon with disfavor in conjunction with small, portable water filters because of the added complexity to the water filter. A separate discharge tube is generally required to direct the pressurized water being relieved outside the filter.

Another problem associated with conventional portable water filters involves the mechanical means for forcing water through the filter. Prior filtering devices have included piston-cylinder arrangements where a rod is coupled to the piston so as to coincide with the orthogonal axis of the cylinder. The rod is typically secured in place relative to the cylinder by a wall with a central aperture through which the rod must pass. This keeps the plane of the piston perpendicular to the orthogonal axis of the cylinder at all times while the piston moves back and forth in the cylinder.

Prior filters with piston-cylinder arrangements are usually actuated by pumping the rod directly in and out of the cylinder as is done by a typical hand-held tire pump. This type of ergonomic pumping action is awkward and makes the overall process of filtering water complicated and difficult.

Lever-action pumps have traditionally not been used for portable water filters. Such lever-action pump handles require many linkage parts to ensure that as the piston is moved back and forth, it constantly remains in a plane perpendicular to the orthogonal axis of the cylinder. To achieve this constant perpendicularity with the lever-action handle, several linkage members are needed which increases the overall friction, number of parts that may fail or wear out, and the overall complexity of the filter device.

Still another problem associated with portable water filters relates to the filter medium on the inside of-the water filter itself. Over time, the filter medium will become clogged with the filtered impurities. Therefore, it is inevitable that the filter of the medium must be changed or backflushed in some way. Removal and replacement of filter mediums on traditional portable water filters is generally complicated and expensive.

A further problem exists with respect to damage to the filter element from impact resulting from, for example, dropping the filter. Water filters have traditionally lacked the ability to absorb shock to prevent damage to the filter medium. Carbon, a filter medium commonly used in portable water filters, is particularly susceptible to breakage upon impact.

There are also problems associated with the build up of impurities inside the filter, which may later be discharged from the filter. For example, carbon filters are commonly used in portable water filters to filter bacteria and other microscopic impurities from the water. Once used, some water will remain inside the carbon filter medium. The water that remains in the carbon filter medium may act as a breeding ground for bacteria. When this occurs toward the downstream end of the carbon filter, the water initially discharged after a long period of non-use may be contaminated with living organisms.

Some other problems associated with portable water filters involve the vessel into which the filtered water is placed for use. Traditionally, portable water filters have been cumbersome and awkward in their pumping.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a portable water filter with an inlet hose that can be adjusted to draw water from a body of water at a variety of depth.

Another object of the invention is to provide a prefiltering device at the end of the inlet hose for preventing relative large-sized impurities from entering into the intake hose.

Still another object of the present invention is to provide a water filter with an inlet hose having an easily replaceable prefilter at the end of the inlet hose.

Yet another object of the invention is to provide a method of relieving pressure inside the water filter if the pressure exceeds a predetermined level.

Another object of the invention is to provide a means for redirecting unfiltered water back down through the inlet hose when the filter medium inside the main filter is clogged.

Still another object of the invention is to provide a water filter through which water can be pumped using the same amount of force regardless of the degree to which the filter medium has been clogged.

Still another object of the invention is to provide a water filter that includes a lever-action handle for pumping water through the filter that is efficient, reduces friction, requires few parts, is more ergonomic, and is less susceptible to breakdown.

Still another object of the present invention is to provide a cartridge filter assembly that absorbs shock and minimizes damage due to impact.

Still another object of the invention is to provide a cartridge filter assembly that is easily removable and economical to replace.

Another object of the invention is to provide a filter means for removing regrowth bacteria that form inside the filter medium before the water is completely discharged from the water filter.

Another object of the invention is to provide a water filter that requires only one person to operate.

Yet another object of the invention is to provide a water filter with a means for directly connecting the discharge end of the filter to a container into which filtered water is discharged.

Another object of the invention is to provide a water filter with a means for storing the inlet supply hose in a convenient manner on the water filter.

Another object of the invention is to provide a water filter with a means for sealing the inside of an open-ended piston-cylinder arrangement so that dirt or other foreign substances will be prevented from entering into the piston-cylinder arrangement.

The foregoing objects, and other objects that will become more apparent from the detailed description that follows, are achieved by providing a portable water filter having a float adjustably coupled to the end of the intake hose and a weight on the end of the intake hose so that the inlet opening can be placed at a given depth in the body of water from which water is being drawn. A prefilter assembly located at the end of the inlet hose prevents relatively large-sized impurities from entering into the inlet hose.

The water filter further comprises a combination check/relief valve which limits the flow of water in one direction during normal operation and discharges water back down the inlet hose if excessive pressure builds up within the filter assembly due to clogging. Water is forced through the water filter by way of a lever-action handle used in combination with a rocking piston to provide an easy-to-use, efficient method for filtering the water.

A unique cartridge filter assembly is provided inside the water filter which is supported at its periphery by opposite O-rings to cushion the filter medium and prevent damage in the event the water filter is subject to impact. The cartridge filter assembly is also easy to remove and inexpensive to replace. The water filter also includes a membrane filter located downstream of the cartridge filter assembly which acts as a final filtering medium to prevent residual regrowth bacteria from being discharged with the filtered water.

An additional feature of the water filter is an adapter base which allows for the filter to be directly connected to a vessel into which the filtered water can be discharged. The water filter further includes a feature for conveniently storing the inlet hose on the filter. A notch is provided on the lever-action handle so the hose can be placed in the notch to secure the handle tightly against the filter body which closes a door to prevent debris and other material from entering into the cylinder body of the piston-cylinder arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, partly in section, of the water filter of the present invention.

FIG. 2 is an exploded perspective view, partly in section, of the water filter of the present invention.

FIG. 3 is a partial sectional side view, taken along line 3--3 of FIG. 1 of the water filter of the present invention.

FIG. 3A is a cross-sectional view taken along line 3A--3A of FIG. 3 of the umbrella valve of the present invention.

FIG. 4 is a side elevational view, partly in section, of the hose and inlet assembly of the present invention.

FIG. 5 is an exploded view of the inlet assembly of the present invention.

FIG. 6 is a partial front elevational view, partly in section, of the check/relief valve of the present invention.

FIG. 7 is a front elevational view, partly in section, of the check/relief valve of the present invention.

FIG. 7A is a magnified view of the check/relief valve, shown in FIG. 7 of the present invention.

FIG. 8 is a partial side elevational view, partly in section, taken along the line of 8--8 of FIG. 7 the piston-cylinder arrangement of the present invention.

FIG. 9 is a partial side elevational view, partly in section, taken along the line of 9--9 of FIG. 7 of the piston-cylinder arrangement of the present invention.

FIG. 10 is a partial side elevational view, partly in section, taken along the line 10--10 of FIG. 7 of the piston-cylinder arrangement of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1 the present invention relates generally to a portable water filter 10 generally comprising an inlet assembly 12 a hose assembly 14 a relief valve assembly 16 a piston-cylinder assembly 18 a main filter assembly 20 a discharge assembly 22 and a handle assembly 24. The water filter is small and lightweight so that it can be used by persons traveling internationally or through the backcountry, such as backpackers, yet the water filter is highly effective for separating impurities from water commonly found in the backcountry, such as bacteria, pesticides, Giardia and other Protozoa.

Referring now to FIGS. 4 and 5 the water filter 10 comprises an inlet assembly 12 which includes a foam piece 26 partially inserted into an end housing 28 which is inserted, in turn, into a supply conduit or inlet hose 30. In one embodiment, the inlet hose is made of a flexible silicone material which is easy to bend to facilitate wrapping the hose around the filter when not in use. It is understood, however, that the hose could be made of any conventional material. A coil spring or cage 32 encapsulates the combination of the hose, the end housing, and the foam. The cage holds the inlet assembly together, and particularly, the foam piece inside the inlet housing. The cage further acts as a weight on the end of the hose. With reference to FIG. 5 the cage has a narrowed portion 32a which gradually increases to an enlarged portion 32b.

The end housing 28 comprises a cylindrical large diameter portion 34 frustoconical portion 36 and a cylindrical, small-diameter portion 38. The final element of the inlet assembly 12 is a compressible foam piece 26 having a plurality of pores 40. The pores are generally equal in size when the foam piece is in an uncompressed state.

In assembling the inlet assembly 12 the narrowed portion 32a of the cage 32 is slid over the end of inlet hose 30 after which the small diameter portion 38 of the end housing 28 is inserted into the hose. A portion of the foam 26 is then compressed (shown in phantom in FIG. 5) and forced into the large-diameter portion 34 and the frustoconical portion 36 of the housing, respectively. The