Water filter abstract
A water filter including a cup into which water may be filled,
and a replaceable filter cartridge removably receivable within the
lower portion of the cup, with the cartridge including a hollow
body having top and bottom openings across which first and second
sheets of filter material extend, and with a mass of activated carbon
being contained within a chamber in the body of the replaceable
cartridge and confined between the two sheets of filter material.
Water filter claims
I claim:
1. A water filter comprising:
a cup having a top opening through which water may be filled into
the cup, and having a bottom outlet through which filtered water
discharges; and
a replaceable filter cartridge removably received within a lower
portion of said cup and through which the water flows to said outlet;
said replaceable cartridge including a hollow body adapted to be
removably placed in said lower portion of the cup and containing
a chamber and a top opening through which water flows downwardly
into the chamber and a bottom opening through which water discharges
from the chamber toward said outlet;
said replaceable cartridge including a first sheet of filter material
extending across said top opening of the cartridge body and peripherally
sealed to the body about said top opening, a second sheet of filter
material extending across said bottom opening of the cartridge body
and peripherally sealed to the body about said bottom opening, and
a mass of activated carbon contained within said chamber between
said first and second sheets of filter material and retained in
the chamber by said sheets;
said lower portion of the cup having a cylindrical vertically extending
side wall, an annular bottom wall extending inwardly at the lower
end of said side wall and containing said outlet at its center,
and an annular essentially horizontal flange extending horizontally
outwardly from and about the upper end of said side wall and connected
peripherally to an upper portion of said cup;
said body of the replaceable cartridge having a vertical cylindrical
side wall extending about said chamber and having an outer surface
of greater diameter than the internal diameter of said side wall
of the lower portion of the cup to be forced fit therein frictionally
retaining the cartridge in the cup while permitting it to be forced
therefrom for replacement;
said body of the cartridge having an annular bottom wall extending
horizontally inwardly from the lower extremity of said side wall
of the cartridge body and containing said bottom opening, said second
sheet of filter material being received at the upper side of said
bottom wall of the cartridge body and being peripherally fusion
sealed thereto;
said body of the cartridge having an annular horizontal flange
extending outwardly from and about the upper extremity of said side
wall of the cartridge body and fusion sealed to the periphery of
said first sheet of filter material;
said bottom opening of the cartridge body and said second sheet
of filter material being smaller than said upper opening of the
cartridge body and said first sheet of filter material, and being
larger than said bottom outlet of the cup.
2. A water filter as recited in claim 1 in which said bottom wall
of the cartridge body has an outer annular horizontal portion at
a first level, and an inner annular horizontal portion at a lower
level to the upper side of which said second sheet of filter material
is secured and which projects downwardly into an annular recess
formed in said bottom wall of the lower portion of the cup.
3. A water filter as recited in claim 2 in which said inner portion
of said bottom wall of the lower portion of the cup has a circular
upwardly projecting rib engageable with the body of the cartridge
about said lower opening therein, said cup having an upwardly projecting
circular rib engageable with the underside of said flange on the
upper portion of the cartridge body.
4. A water filter comprising:
a cup having a top opening through which water may be filled into
the cup, and having a bottom outlet through which filtered water
discharges; and
a replaceable filter cartridge removably received within a lower
portion of said cup and through which the water flows to said outlet;
said lower portion of the cup having a side wall extending thereabout;
said cup having a generally horizontal wall extending outwardly
from and about an upper end of said side wall;
said replaceable cartridge including a hollow body which is adapted
to be removably placed in said lower portion of the cup and containing
a chamber and which has a top opening through which water flows
downwardly into the chamber and a bottom opening through which water
discharges from the chamber toward said outlet;
said replaceable cartridge including a first sheet of filter material
extending across said top opening of the cartridge body and peripherally
sealed to the body about said top opening, a second sheet of filter
material extending across said bottom opening of the cartridge body
and peripherally sealed to the body about said bottom opening, and
a mass of activated carbon contained within said chamber between
said first and second sheets of filter material and retained in
the chamber by said sheets;
said body of the cartridge having a side wall which is a close
fit within said side wall of the lower portion of the cup in a relation
preventing flow of water downwardly therebetween to require that
water flowing to said outlet pass through said filter sheets and
said activated carbon;
said body of the cartridge having a peripheral flange extending
generally horizontally outwardly from the upper end of said side
wall of the cartridge body and received above said generally horizontal
wall of the cup;
said cup having an upper portion containing and defining an upper
water receiving compartment above the top of said cartridge and
above the top of said flange and having a side wall extending about
said compartment and projecting upwardly higher than the flange
from the periphery of said generally horizontal wall of the cup;
said upper compartment within the upper portion of the cup above
said cartridge and said flange being larger in horizontal and vertical
dimension and in volume than said lower portion of the cup which
contains said cartridge.
5. A water filter as recited in claim 4 in which said side wall
of said body of the replaceable cartridge has an outer surface which
is a forced fit within said side wall of said lower portion of the
cup to frictionally retain the cartridge in the cup while permitting
it to be forced therefrom for replacement.
6. A water filter as recited in claim 4 in which said bottom outlet
of the cup is located directly beneath a portion of said replaceable
cartridge at a location enabling a removal instrument to be inserted
upwardly through the bottom outlet into contact with the cartridge
and to force the cartridge upwardly relative to the cup for removal
therefrom.
7. A water filter as recited in claim 4 in which said first sheet
of filter material is peripherally secured to said flange and is
larger horizontally than said second sheet of filter material.
8. A water filter as recited in claim 4 in which said lower portion
of the cup has a bottom wall containing said outlet, said cartridge
body having a bottom wall containing said bottom opening and having
an undersurface extending about and adjacent said bottom opening
and which is engageable downwardly with said bottom wall of the
lower portion of the cup, said second sheet of filtering material
being peripherally secured to the upper side of said bottom wall
of the cartridge body and being located at a level above that of
said undersurface of the bottom wall of the cartridge body.
9. A water filter as recited in claim 4 in which said lower portion
of the filter cup has upwardly facing shoulders at the upper and
lower ends of said replaceable cartridge, and which have essentially
annular upwardly projecting ribs for contacting and supporting the
cartridge body at locations essentially about said upper and lower
openings respectively.
Water filter descriptionBACKGROUND OF THE INVENTION
This invention relates to improved water filters for removing from
drinking water certain substances having unwanted taste and odor
characteristics.
There are on the market water filters of a type including a cup
into which water to be filtered is filled, and having a mass of
activated carbon contained in a lower portion of the cup and through
which the water flows before reaching an outlet in the bottom of
the cup. In some such prior devices, the activated carbon has been
confined between upper and lower sheets of filter material, so that
the water first flows through the upper of these sheets for an initial
filtering action, then flows through the activated carbon to attain
removal of substances affected by such carbon, and finally flows
through the lower filter sheet to the outlet of the device. After
discharge from the filter unit, the water may be collected in a
drinking glass or the like, or in a water bottle or other receptacle
for later use. Such filters are not intended to purify the water,
but rather to render it more palatable.
SUMMARY OF THE INVENTION
The present invention provides an improved water filter of the
above discussed general type, and particularly one in which the
active filtering elements are easily replaceable after a period
of use, and after their filtering effectiveness has diminished by
accumulation of separated substances on the filter sheets and activated
carbon, to thereby enable reinstatement of the overall filter to
its original effectiveness without the necessity for replacement
of the main structure of the device. To attain this result, a unit
embodying the invention includes a filter cartridge which is contained
within the lower portion of the main filter cup and is removable
therefrom, and which includes the filter sheets and the activated
carbon therebetween. The cartridge may be lightly frictionally held
in place in the bottom of the cup to give the assembly an integrated
characteristic in use, while still permitting the filter cartridge
to be easily removed from the cup for replacement when desired.
The replaceable cartridge includes a hollow body receivable within
the lower portion of the main filter cup, and having an upper opening
through which the water to be filtered enters the cartridge body
and a lower opening through which the filtered water leaves the
cartridge body, with a chamber being provided between the upper
and lower openings for receiving the activated carbon filtering
material in confined relation. The upper and lower sheets of filter
paper or other filtering material extend across the top and bottom
openings respectively of the filter body, and are peripherally secured
thereto, desirably by forming the hollow body of resinous plastic
material and fusion bonding it to the peripheries of the two filter
sheets, preferably by ultrasonic bonding. To achieve the discussed
light frictional retention of the cartridge in the lower portion
of the cup, the cartridge body may have a side wall receivable within
and engageable with a side wall of the cup, and having an outer
surface which is very slightly oversize with respect to the inner
surface of the cup wall to be a slightly forced fit therein, thereby
frictionally retaining the cartridge in place in the cup while permitting
it to be forced therefrom when desired. These side walls of the
cartridge body and lower portion of the cup may extend vertically,
preferably both being cylindrical.
At its upper end, the cartridge body may have a peripheral flange
extending horizontally outwardly therefrom for engaging a support
surface in the cup, and to which flange the upper filter sheet may
be secured. At the lower end of the vertical cylindrical side wall
of the cartridge body, that body may have an inwardly extending
generally horizontal bottom wall containing the bottom opening across
which the lower sheet of filter material extends.
BRIEF DESCRIPTION OF THE DRAWING
The above and other features and objects of the invention will
be better understood from the following detailed description of
the typical embodiment illustrated in the accompanying drawing,
in which:
FIG. 1 is a central vertical section through a filter device constructed
in accordance with the invention;
FIG. 2 is a view similar to FIG. 1 showing the manner in which
the filter cartridge can be forced from the filter cup for replacement;
FIG. 3 is a top plan view of the filter cartridge, taken on line
3--of FIG. 2; and
FIG. 4 is a bottom plan view of the filter cartridge, taken on
line 4--4 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates at 10 a water filter constructed in accordance
with the invention and which is typically to be utilized for filling
filtered water into a drinking cup represented at 11 or any other
receptacle for containing filtered water. The device 10 includes
a main filter cup 12 having an open top 13 through which the water
to be filtered is poured into the cup, and having a bottom wall
14 containing a central outlet opening or spout 15 through which
the filtered water is discharged into cup 11. The filtering action
is attained by a replaceable filter cartridge 16 removably contained
within the lower portion of cup 12.
The cup 12 is constructed the same as that of a prior filter device
in which the filtering materials are retained permanently in the
lower portion of the cup rather than in a replaceable cartridge.
To describe the cup in greater detail, the cup is preferably formed
of an appropriate slightly resiliently deformable resinous plastic
material, such as polyethylene, and may be circular in horizontal
section and about a vertical axis 17 with the upper portion of
the cup forming a frusto-conically flaring side wall 18 which progressively
increases in horizontal dimension between the location 19 of FIG.
1 and the upper circular top edge or opening 13. At the location
19 the side wall of the cup extends inwardly to form a horizontal
annular portion 20 forming an upwardly facing horizontal shoulder
or surface 21 which preferably has, at a location midway between
its radial inner and outer extremities, circular upwardly projecting
rib or ring of material 22 for engaging the cartridge 16 in supporting
relation. This rib 22 when viewed in vertical section in a plane
containing axis 17 may have the upwardly rounded configuration
illustrated in
FIG. 1.
Extending downwardly from the inner edge of horizontal portion
20 of the outer cup 12 the side wall of that cup has a vertical
cylindrical portion 23 centered about axis 17 and terminating
downwardly at an in-turned bottom wall 24 of the cup. This bottom
wall is annular about axis 17 and, in extending radially inwardly
from its peripheral edge 25 forms first an annular horizontal portion
26 of the bottom wall, is then stepped downwardly to form a second
annular portion 27 at a slightly lower level, and at the inner edge
of that portion is stepped downwardly again to form a third and
radially innermost horizontal annular portion 28 at a still lower
level. The discharge spout 15 is formed at the center of this inner
lower portion of the bottom wall 24. The upper surfaces 29 30 and
31 of the portions 26 27 and 28 are stepped downwardly as illustrated,
and are all desirably directly horizontal except for the provision
on the intermediate surface 30 at a location midway between its
radially inner and outer extremities, of a circular rib 32 which
is centered about axis 17 and projects upwardly above the level
of the remainder of the horizontal surface 30 to engage cartridge
16 in supporting relation. This rib 32 as viewed in vertical section
may be rounded in the same manner as discussed in connected with
rib 22. The strength of the lower portion of the cup may be improved
somewhat by provision of a series of circularly spaced radial ribs
33 at the outer side of vertical side wall 23 as shown.
The replaceable filter cartridge 16 includes a hollow outer body
or case 34 which is annular about the vertical axis 17 of the device
and may be formed of an appropriate resinous plastic material, such
as polyethylene. The body forms within its interior a cylindrical
chamber 35 within which a mass of activated carbon filtering pellets
36 is contained, typically of a size to pass a 12.times.40 U.S.
screen, with these pellets being confined between and contained
by an upper sheet 37 of filtering material and a lower sheet 38
of such material. The body 34 has a vertical cylindrical side wall
39 centered about axis 17 and an upper horizontal annular flange
40 projecting radially outwardly from the upper end of side wall
39. This flange 40 has a horizontal undersurface 41 engageable with
rib 22 of the cup in supported relation when the cartridge is inserted
in the cup. The upper surface 42 of flange 40 is horizontal, except
at the location of an upwardly projecting annular rib 43 centered
about axis 17 by which the periphery of top filter sheet 37 is annularly
bonded to flange 40. This rib 43 may initially be molded to a configuration
similar to ribs 22 and 32 of cup 12 but may be fused under pressure
and while in contact with sheet 37 to form a seal therebetween.
This fusion may be attained by ultrasonic bonding of sheet 37 to
rib 43. The sheet 37 may be externally circular, having a peripheral
edge 44 of a diameter corresponding approximately to the external
diameter of flange 40. The filter sheets 37 and 38 may be any known
type of filtering paper or paper-like sheet material capable of
removing particulate matter from the water being filtered, and capable
of effectively retaining the activated carbon 36 within chamber
35.
The outer surface of cylindrical side wall 39 of the cartridge
body is preferably of a diameter slightly greater than the diameter
of the inner surface of side wall 23 of cup 12 the difference in
diameters typically being between about one and three thousands
of an inch, so that the cartridge body 34 must be forced slightly
downwardly into the FIG. 1 position of reception within the lower
portion of the cup, with slight resilient deformation of the two
side walls 39 and 23 to permit such entry, and with resultant frictional
retention of the cartridge in the lower portion of the cup and in
fixed relation thereto. The filter cartridge is then permanently
retained in that assembled position for handling with the cup without
unintentional disassembly, and with an effective seal being provided
by virtue of the tight fit between the parts, until the filter cartridge
is subsequently forced upwardly out of its position of reception
in the cup for replacement.
At the lower extremity of the vertical cylindrical side wall 39
of the cartridge body 34 the material of that body forms an inwardly
extending bottom wall 45 of the cartridge body, which is annular
about axis 17 and contains a circular opening 46 centered about
that axis and through which water discharges downwardly from the
filter cartridge. Bottom wall 45 in extending radially inwardly
from the lower edge 47 of side wall 39 forms first an annular horizontal
portion 48 of the bottom wall, and then an annular radially inner
portion 49 located at a level slightly beneath the level of outer
portion 48. The upper surface 50 of portion 48 of bottom wall 45
is horizontal, and the upper surface 51 of inner portion 49 of the
bottom wall is similarly horizontal but at a level beneath that
of surface 50 with a circular upwardly projecting rib 52 being
formed at the center of surface 51 for attachment to the periphery
of bottom filter sheet 38. This bottom sheet 38 has an outer circular
edge 53 of a diameter just slightly smaller than the diameter of
the recess formed by the downward offset of bottom wall portion
49 and is annularly secured in sealed relation to rib 52 by fusing
the material of the rib, desirably by ultrasonic welding techniques.
Lower filter sheet 38 may be formed of the same kind of filtering
material as has been discussed in connection with upper sheet 37.
In using the device illustrated in the drawing, the replaceable
filter cartridge 16 is first inserted downwardly into cup 12 to
the position illustrated in FIG. 1 being pressed downwardly as
the cartridge enters the cavity formed within the cylindrical side
wall 23 of the bottom portion of the cup. The forced fit relationship
between the side of the cartridge and wall 23 frictionally retains
the cartridge in position as previously discussed and until intentionally
removed from the cup. To fill filtered water into a receptacle such
as that shown at 11 in FIG. 1 the device 10 is placed over and
in a position of support on the upper edge of that receptacle, and
water is poured into the upper end of cup 12 to flow downwardly
through the filter material 37 and activated carbon 36 and the bottom
sheet 38 for discharge downwardly through outlet 15 to the receptacle
11. Particulate matter and substances having adverse taste and odor
characteristics are removed by the filtering materials, including
for example chlorine, unpalatable impurities, and the like, to give
the filtered water a vastly improved taste and odor.
The proportioning of the bottom outlet 15 and the openings at the
top and bottom of the filter cartridge, as well as the relative
positioning of the bottom filter sheet 38 relative to outlet 15
are such as to slow the flow of water downwardly through the device
just sufficiently to attain an effective filtering action, while
at the same time maintaining a rapid enough flow to fill the cup
11 as quickly as possible. In this connection, it is considered
of importance that the bottom filter sheet 38 is secured to the
upper side of bottom wall 45 of the cartridge body, at a level slightly
above the undersurface 49 of bottom wall 45 by which the cartridge
is supported. This leaves a space of sufficient size beneath sheet
38 and above the upper surface 31 of the bottom wall of the cup
to enable water to accumulate fairly rapidly for discharge downwardly
through the outlet.
After the device has been in use for a substantial period of time,
impurities may accumulate on filter sheets 37 and 38 and on the
activated carbon 36 descreasing the effectiveness of these filtering
elements. When that condition is noted, the user can remove the
replaceable filter cartridge 16 and insert another such cartridge
in the cup 12 to reinstate the entire unit to its original highly
effective condition. FIG. 2 illustrates the manner in which the
frictionally retained cartridge 16 can be removed, specifically
by insertion upwardly through the tubular outlet spout 15 of an
elongated removal instrument or tool 54 acting upwardly against
the center of the bottom sheet 38 to force cartridge 16 upwardly
relative to the cup and to the FIG. 2 position from which it can
be withdrawn. An item which can very effectively be used as the
removal element of FIG. 2 is a pencil having an eraser at its end,
with the eraser being placed in engagement with the filter sheet
38 to act thereagainst without puncturing through the sheet.
While a certain specific embodiment of the present invention has
been disclosed as typical, the invention is of course not limited
to this particular form, but rather is applicable broadly to all
such variations as fall within the scope of the appended claims.
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