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
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