Water dispenser abstract
An automatic filter shutoff device removably connected to a water
container and in fluid communication with a water dispenser, which
is adapted to monitor water dispensing and disable dispensing after
a predetermined amount of water usage. The device includes a housing
containing a water filter and removably connected to the water container;
a monitoring and disabling mechanism having a shutoff apparatus
moveable between first and second locations, the first location
being one in which water dispensing is monitored by the mechanism,
and the second location being one in which the mechanism is placed
in an interfering position with the connection between the housing
and the water container. The shutoff apparatus automatically moves
into the second location after the predetermined amount of water
usage has occurred, and without interrupting water dispensing from
the then-connected water container, so that the used filter shutoff
device must be replaced in order to reestablish connection to a
successive water container. A filter mechanism is also provided
with a housing containing a water filter and having a throat removably
connected to a bottled water container. The throat is a restricted
orifice sized to permit a volumetric flow rate of not greater than
about 7500 ml./min. of water passage during inversion of the water
container and initial flow from the container into the filter. A
plurality of vent holes are located in an upper surface of the filter
housing and sized to permit air from the filter to escape into the
water container and allow continuous water flow from the container
into the filter. When a new water container is connected to the
housing, the water level within the filter does not reach the vent
holes in the filter housing.
Water dispenser claims
We claim:
1. An automatic filter shutoff device removably connected to a
water container and in fluid communication with a water dispenser,
the device being adapted to monitor water dispensing and disable
dispensing after a predetermined amount of water usage, comprising:
a housing containing a water filter and removably connected to the
water container; a monitoring and disabling mechanism having a shutoff
apparatus moveable between first and second locations, the first
location being one in which water dispensing is monitored by the
mechanism, and the second location being one in which the mechanism
is placed in an interfering position with the connection between
the housing and the water container; wherein the shutoff apparatus
automatically moves into the second location after the predetermined
amount of water usage has occurred, and without interrupting water
dispensing from the then-connected water container, so that the
used filter shutoff device must be replaced in order to reestablish
connection to a successive water container.
2. The automatic filter shutoff device of claim 1 wherein the
predetermined amount of water usage generally corresponds to the
useable life of the filter.
3. The automatic filter shutoff device of claim 1 wherein the
device is adjustable so that dispensing may be disabled after differing
amounts of water usage.
4. The automatic filter shutoff device of claim 1 wherein the
shutoff apparatus comprises a plunger whose vertical height may
be varied, and wherein the second location comprises a position
in which the plunger obstructs the connection of the filter housing
and the water container.
5. The automatic filter shutoff device of claim 1 wherein the
monitoring and disabling mechanism further comprises a filter cap
with a downwardly depending leg having a locking window engageable
with a locking tab located on the shutoff apparatus.
6. The automatic filter shutoff device of claim 1 wherein the
plunger has a top surface with a throat opening and annular side
walls with spaced openings, and wherein the surface area of the
orifice is approximately equal to the surface area of the side openings.
7. The automatic filter shutoff device of claim 1 wherein the
monitoring and disabling mechanism further comprises a filter cap
mounting radially disposed, opposing teeth, and the shutoff apparatus
comprises a rotary indexer having a radially protruding tab iteratively
communicating with the teeth, and wherein the rotary indexer monitors
water dispensing by tracking the number of water containers used
during dispensing.
8. The automatic filter shutoff device of claim 1 wherein the
monitoring and disabling mechanism comprises a NSF-compliant performance
indication device.
9. The automatic filter shutoff device of claim 5 wherein the
engaging surfaces of the locking tab and locking window are angled
to facilitate entry of the tab within the window.
10. The automatic filter shutoff device of claim 5 wherein the
engaging surfaces of the locking tab and locking window are angled
to prevent disengagement of the tab from the window.
11. The automatic filter shutoff device of claim 1 wherein a visual
indicator is provided to advise the user that the filter is nearing
the end of its useful life.
12. The automatic filter shutoff device of claim 11 wherein the
visual indicator comprises a color band located on an outer surface
of the filtering and disabling mechanism.
13. The automatic filter shutoff device of claim 3 wherein the
monitoring and disabling mechanism comprises a visual indication
to facilitate adjusting of the mechanism for differing water usages.
14. The automatic filter shutoff device of claim 1 wherein the
monitoring and disabling mechanism comprises a helical-shaped spring.
15. The automatic filter shutoff device of claim 1 wherein the
monitoring and disabling mechanism comprises a rotary index engageable
with teeth having a number corresponding to the predetermined amount
of water usage.
16. A filter mechanism connected to a bottled water container adapted
to be inverted and placed in fluid communication with a water dispenser,
comprising: a housing containing a water filter with a throat removably
connected to the bottled water container, the throat comprising
a restricted orifice sized to permit a volumetric flow rate of not
greater than about 7500 ml./min. of water passage during inversion
of the water container and initial flow from the container into
the filter; a plurality of vent holes located in an upper surface
of the filter housing and sized to permit air from the filter to
escape into the water container and allow continuous water flow
from the container into the filter; wherein when a new water container
is connected to the housing, the water level within the filter does
not reach the vent holes in the filter housing.
17. The filter mechanism of claim 16 further comprising a monitoring
and disabling mechanism having a shutoff apparatus moveable between
first and second locations, the first location being one in which
water dispensing is monitored by the mechanism, and the second location
being one in which the mechanism is placed in an interfering position
with the connection between the housing and the water container,
wherein the shutoff apparatus automatically moves into the second
location after the predetermined amount of water usage has occurred,
and without interrupting water dispensing from the then-connected
water container, so that the filter shutoff device may not be connected
to a successive water container.
18. The filter mechanism of claim 16 wherein the restricted orifice
has a diameter of less than about one inch.
19. The filter mechanism of claim 16 wherein the restricted orifice
has a diameter of about 3/4 inches.
Water dispenser description
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to the dispensing
of filtered, bottled water. More specifically, the invention relates
to a shutoff device that monitors the number of bottles used and
then disables further use of the filter when the filter has reached
the end of its useful life. The device can also provide an early
warning signal to the user that the filter is nearing the end of
its useful life.
[0002] Self-contained filters for removing unwanted minerals and
chemicals such as chlorine have become increasingly popular with
bottled water users. These filters may be threadably attached or
otherwise connected to the opening of a bottled water container,
or may be contained within the water dispenser unit. Various devices
are also known for monitoring water flow and then interrupting water
flow after a predetermined use.
[0003] Some prior art devices have provided techniques for opening
a pressure vessel containing a carbon filter used in water purification.
However, such techniques are cumbersome and undesirable for the
user. Thus, it is desirable to provide an economical self-contained
dispenser shutoff and filter cartridge which may be easily replaced
when a monitor indicates that the filter has reached the end of
its useful life.
[0004] In general, prior art patents and known water dispensing
disabling devices (herein termed "shutoff devices") with
a filter have tended to concentrate on ways of interrupting water
flow through the bottle opening once the filter has reached the
end of its useful life, by physically blocking water flow However,
this may result in an interruption in dispensing when the water
container still has a substantial volume of water in it, which is
not desirable from a user viewpoint.
[0005] To overcome this problem, some prior art devices provide
specific shutoff mechanisms so that when the filter cartridge is
removed, dispensing is stopped; these devices also require a separate
filter monitor device to visually or audibly warn the user that
the filter has reached the end of its useful life. Many such shutoff
devices have also tended to have a number of moving parts, increasing
the risk of part malfunction.
[0006] However, there is a need for a water filter shutoff device
which monitors water usage and automatically disables dispensing
when the filter has reached the end of its useful life, without
the need to rely on visual or audible warning signals. Such a filter
shutoff device would also preferably meet the following constraints.
Given space constraints, the shutoff device preferably is integral
with the filter, and should not unduly impede flow through the filter.
The shutoff device would also preferably allow presetting at the
time of manufacture to change the allowable water flow or application
uses, so that the device could be used with differently rated filters
and differently sized water containers. The device should be economical
to manufacture and preferably not require an entirely new mold or
any substantial additional investment in assembly equipment or fixtures,
while also being relatively simple in design with few moving parts
to reduce quality control risks. The shutoff device would also preferably
disable dispensing, without interrupting water flow from the currently
used water container, when a monitor indicates the useful life of
the filter is over.
[0007] A filter shutoff device preferably meets NSF criteria, including
qualifying as a filter "performance indication device"
(PID) under NSF standards, and include component materials that
have existing NSF approval for extraction. If no filter monitor/PID
is provided for a water dispenser with a filter, obtaining NSF approval
currently requires that the filter be tested to work at 200% of
its rated capacity. If a PID is provided, the filter need only be
tested to work at 120% of its rated capacity for NSF approval. For
example, if a filter is rated for 150 gallons, and a filter PID
is provided, the filter need only have a capacity of 180 gallons,
as opposed to 300 gallons if no filter PID is provided. This is
a significant added cost feature for a filter manufacturer, since
providing a filter capable of filtering 300 gallons requires additional
media content resulting in a significant added cost.
[0008] Filter shutoff devices must also be provided with venting
in some manner to allow continuous water flow, without "lock
up". One problem with such devices is that, upon initial use,
as water from the inverted water bottle flows into the device, water
pressure/water hammer conditions may cause unfiltered water to leak
or spurt out of the venting channels and into the dispensing unit.
A sufficient volume of water may escape filtration in this manner,
such that the device may not receive NSF approval for, e.g., lead
testing. It is also desirable to provide a filter shutoff device
which overcomes this problem.
[0009] Accordingly, an object of the present invention is to provide
a shutoff device integral with a filter and useable with a water
dispenser, in which the water dispenser is automatically disabled
at the end of the useful life of the filter.
[0010] Another object of the invention is to provide a filter shutoff
device which does not impede or interrupt water flow between the
water dispensing device and a water source such as an inverted water
bottle. A further object is to provide such a device that qualifies
as filter PID under NSF standards, enabling the more economical
manufacture of the filter.
[0011] Yet another object is to provide a filter shutoff device
which may be manufactured in an economical manner, such that the
device monitors the number of water containers used, disables further
dispensing after a predetermined number of uses, and then may be
discarded and replaced with a new device.
[0012] A further object is to provide a filter shutoff device which
automatically disables the connection between the device and a water
container, rather than simply providing a visual indication of end
of filter life, and rather than maintaining the ability to make
this connection and physically impeding or interrupting water flow.
[0013] A still further object is to provide such a device with
an appropriate size and configuration, together with appropriately
located and sized vent holes, to ensure that unfiltered water does
not leak out of the device and be dispensed.
Definition of Claim Terms
[0014] The following terms are used in the claims of the patent
as filed and are intended to have their broadest meaning consistent
with the requirements of law. Where alternative meanings are possible,
the broadest meaning is intended. All words used in the claims are
intended to be used in the normal, customary usage of grammar and
the English language.
[0015] "Automatic filter shutoff device" means a device
in fluid communication with a water container which filters water
and then interferes with the ability to dispense water from the
container after a predetermined amount of water usage (i.e., the
"shutoff" feature), which may generally correspond to
the useable life of the filter, has been reached. "Automatic"
in this context means that shutoff occurs without the need for user
intervention, such as without the need for the user to respond to
a visual or audible signal from a filter monitor.
[0016] "Monitoring and disabling mechanism" means a mechanism
which monitors filter life by monitoring water usage, and which
includes a shutoff feature.
SUMMARY OF THE INVENTION
[0017] The objects mentioned above, as well as other objects, are
solved by the present invention, which overcomes disadvantages of
prior filter shutoff devices for water dispensers, while providing
new advantages not believed associated with such devices.
[0018] In one preferred embodiment, An automatic filter shutoff
device is provided, and is removably connected to a water container
and in fluid communication with a water dispenser. The device is
adapted to monitor water dispensing and disable dispensing after
a predetermined amount of water usage. The device includes a housing
containing a water filter and removably connected to the water container;
and a monitoring and disabling mechanism having a shutoff apparatus
moveable between first and second locations, the first location
being one in which water dispensing is monitored by the mechanism,
and the second location being one in which the mechanism is placed
in an interfering position with the connection between the housing
and the water container. The shutoff apparatus automatically moves
into the second location after the predetermined amount of water
usage has occurred, and without interrupting water dispensing from
the then-connected water container, so that the used filter shutoff
device must be replaced in order to reestablish connection to a
successive water container. Preferably, the predetermined amount
of water usage generally corresponds to the useable life of the
filter.
[0019] In a preferred embodiment, the filter shutoff device is
adjustable so that dispensing may be disabled after differing amounts
of water usage. In one preferred embodiment, the shutoff apparatus
includes a plunger whose vertical height may be varied, and the
second location is one in which the plunger obstructs the connection
of the filter housing and the water container. The monitoring and
disabling mechanism may include a filter cap with a downwardly depending
leg having a locking window engageable with a locking tab located
on the shutoff apparatus. The engaging surfaces of the locking tab
and locking window may be angled to facilitate entry of the tab
within the window, and to prevent disengagement of the tab and window.
[0020] In a particularly preferred embodiment, the plunger has
a top surface with a throat opening and annular side walls with
spaced openings, and wherein the surface area of the orifice is
approximately equal to the surface area of the side openings.
[0021] The monitoring and disabling mechanism may include a filter
cap mounting radially disposed, opposing teeth, and the shutoff
apparatus may include a rotary indexer having a radially protruding
tab iteratively communicating with the teeth. In this embodiment,
the rotary indexer monitors water dispensing by tracking the number
of water containers used during dispensing. Preferably, the monitoring
and disabling mechanism is a NSF-compliant performance indication
device.
[0022] A visual indicator, such as a color band located on an outer
surface of the filtering and disabling mechanism, may be provided
to warn the user that the filter is nearing the end of its useful
life. The monitoring and disabling mechanism may also include a
visual indication to facilitate adjusting of the mechanism for differing
water usages.
[0023] In an alternative embodiment, the monitoring and disabling
mechanism may include a helical-shaped spring, and a rotary index
engageable with teeth having a number corresponding to the predetermined
amount of water usage.
[0024] In another aspect of the invention, a filter mechanism is
provided which is connected to a bottled water container and adapted
to be inverted and placed in fluid communication with a water dispenser.
The filter mechanism includes a housing containing a water filter
with a throat removably connected to the bottled water container.
The throat is a restricted orifice sized, such as less than one
inch or about 3/4-inches in diameter, for example, to permit a volumetric
flow rate of not greater than about 7500 ml./min. of water passage
during inversion of the water container and initial flow from the
container into the filter. A plurality of vent holes located in
an upper surface of the filter housing are provided; the vent holes
are sized to permit air from the filter to escape into the water
container and allow continuous water flow from the container into
the filter. When a new water container is connected to the housing,
the water level within the filter does not reach the vent holes
in the filter housing. This embodiment may, but need not, including
a monitoring and disabling mechanism having a shutoff apparatus
as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The novel features which are characteristic of the invention
are set forth in the appended claims. The invention itself, however,
together with further objects and attendant advantages thereof,
will be best understood by reference to the following description
taken in connection with the accompanying drawings. The drawings
illustrate one preferred embodiment of the present invention. As
further explained below, it will be understood that other embodiments,
not shown in the drawings, also fall within the spirit and scope
of the invention.
[0026] FIG. 1 is a perspective view of a water bottle being filled,
together with one preferred embodiment of a filter shutoff device
according to the present invention;
[0027] FIG. 2 is a perspective view showing the threaded connection
of a preferred embodiment of the filter shutoff device according
to the present invention to a water bottle;
[0028] FIG. 3 is a perspective view showing the filter shutoff
device, now attached to the water bottle, just prior to seating
onto the upper housing of a water dispenser;
[0029] FIG. 4 is a perspective view showing various components
of a preferred filter shutoff device according to the present invention;
[0030] FIG. 5 is a perspective view of the preferred, assembled
filter shutoff device;
[0031] FIG. 6 is a top view of FIG. 5;
[0032] FIG. 7 is a sectional view along reference line 7-7 of FIG.
6;
[0033] FIG. 8 is a side and planar perspective view of a preferred
form of the plunger component of the filter shutoff device;
[0034] FIG. 9 is a side and planar perspective view of the plunger
and a partial cross-sectional view of the filter cap;
[0035] FIG. 10 is a side and planar partial, cross-sectional view
of the plunger and filter cap;
[0036] FIG. 11 is a side and planar partial, cross-sectional view
of the plunger, filter cap and filter housing;
[0037] FIG. 12 is a side and planar perspective view of the plunger,
filter cap, spring and filter housing;
[0038] FIG. 13 is a side and bottom perspective view of the lower
portions of the plunger and filter cap;
[0039] FIG. 14 is an exploded view of the area circled "14"
in FIG. 13;
[0040] FIG. 15 is a side cross-sectional view of the preferred
assembled filter shutoff device;
[0041] FIG. 16 is an exploded view of the locking mechanism of
the preferred filter shutoff device;
[0042] FIG. 17 is a side cross-sectional view of an alternative
embodiment of the filter shutoff device of the present invention;
[0043] FIGS. 18 and 19 are partial, side cross-sectional views
showing two positions of the locking mechanism of an alternative
filter shutoff embodiment;
[0044] FIG. 20 is a side and planar cross-sectional view of the
alternative filter shutoff embodiment of FIG. 17;
[0045] FIG. 21 is a side and planar perspective view of the monitoring
and shutoff components of the alternative filter shutoff device
of FIG. 17;
[0046] FIG. 22 is a side and planar perspective view of the assembled
components shown in FIG. 21;
[0047] FIGS. 23-25 are side, enlarged views of the FIG. 17 embodiment
showing opposed teeth and their interaction with a tab of the alternative
filter shutoff device;
[0048] FIG. 26 is a partial side and cross-sectional view of an
alternative, one-piece embodiment of the filter shutoff device of
the present invention;
[0049] FIG. 27 is a partial sectional view along reference line
27/27 of FIG. 26;
[0050] FIG. 28 is a sectional view along reference line 28/28 of
FIG. 26; and
[0051] FIG. 29 is an exploded view of a portion of filter cap 80
of FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0052] Set forth below is a description of what are currently believed
to be the preferred embodiments and/or best examples of the invention
claimed. Future and present alternatives and modifications to these
preferred embodiments are contemplated. Any alternatives or modifications
which make insubstantial changes in function, in purpose, in structure
or in result are intended to be covered by the claims of this patent.
[0053] Referring first to FIGS. 1-3 a water container such as
water bottle 20 is shown, together with a preferred embodiment of
the filter shutoff device of the present invention, generally referred
to as 30. While it is preferred that water bottle 20 have threads
35 that allow threaded connection with mating threads 25 on the
neck of water bottle 20 a threaded connection is not required.
[0054] Referring to FIG. 3 filter shutoff device 30 is sized and
shaped to permit its placement within opening 27 of water cooler
housing 26. (The particular water dispenser chosen for use is of
little importance to the present invention.) For this purpose, filter
device 30 may include an enlarged rim or neck 37 that rests on the
top peripheral wall 27a of aperture 27.
[0055] Referring now to FIGS. 4-6 one preferred embodiment of
filter device 30 includes the following components: filter cap 80;
plunger 90; spring 57; support or media retaining ring 33; and upper
and lower filter pads 32a, 32b. Upper pad 32a is preferably sonic-welded
to ring 33 inside rim 33a; lower pad 32b is preferably sonic-welded
to the lower interior of filter housing 36. Pads 32a, 32b maintain
the filter media, such as activated charcoal, in place within filter
housing 36. During assembly, plunger 90 is placed down through within
center opening 92a of plunger 90. Spring 57 compresses against plunger
90 and, in turn, is compressed by retaining ring 33; compression
is maintained on plunger 90 for the reasons described below. Filter
cap 80 may be sonic-welded to the upper surface of filter housing
36 since, in the preferred embodiment, filter shutoff 30 is designed
to be replaced, rather than cleaned and re-used, when the useful
life of the filter is over. Filter housing 36 is preferably generally
cylindrical in shape, as shown, and includes passages 38 (FIG. 11)
in its lower surface which permit water passage through the lower
end of filter housing 36. Ribs 113 on the outer surface of housing
36 facilitate gripping of the housing by the user. Filter cap 80
includes vent holes 120 which, in the preferred embodiment shown,
are six in number.
[0056] Referring to FIG. 8 a preferred form of plunger 90 includes
an annular top surface 92 with a restricted throat opening 92a.
Legs 93 project downwardly from top surface 92 and include projections
93b and retaining tabs 93a. Annular wall 91 and legs 93 are separated
by arcuate openings such as U-shaped openings, as shown.
[0057] Referring to FIGS. 7 and 10 filter cap 80 has an inner
annular wall 83 with internal threads 35. Annular wall 83 houses
an opposing series of angled teeth, lower teeth 81 and upper teeth
82. Prior to installation of a water bottle, projection 93b of plunger
90 is in an upper position in between upper teeth 82. Upon installation
of water bottle 20 projection 93b will move straight down about
1/4 inch (equal to the distance that the lower edge of the water
bottle must travel to meet the filter cap threads 35) until projection
93b lies between two lower teeth 81. As the water bottle is threaded
onto the filter cap, projection 93b will continue to move downward
between the two lower teeth 81. Referring to FIG. 29 projection
93b preferably traverses the path shown by circuit 188.
[0058] Filter cap 80 and plunger 90 are preferably designed such
that projection 93b does not touch either the upper surface 82a
of upper teeth 82 or the lower surface 81b of lower teeth 81 (see
FIG. 10), so that projection 93b is not stressed during use. While
other dimensions may obviously be used, in a preferred embodiment
upper teeth may have a length equal to the length of projection
93b teeth 81. For example, in the preferred embodiment, the shorter
and longer sides of upper teeth 82 may have a length of 0.062 and
0.109 inches, respectively, while the shorter and longer sides of
lower teeth 81 may have a length of 0.253 and 0.294 inches, respectively.
(The individual teeth may vary slightly in length, given the individual
sections of the collapsible cored use to mold the filter cap.) By
designing the filter cap so that the lower teeth 81 are longer than
the upper teeth 82 this ensures that follower projection 93b will
index over and into position so that when threading the filter cap
onto the bottle, projection 93b will continue down the correct channel
between the lower teeth, and avoid backtracking of projection 93b
due to clockwise rotation of the threading action.
[0059] In operation, and referring now to FIGS. 7-16 plunger 90
rotates as filter shutoff device 30 is replaced and connected to
new water bottles. Plunger rotation is caused by the interaction
of projection 93b with opposing angled teeth 81 82. During normal
water dispensing and filter use, plunger 90 is positioned at a vertical
level that permits threaded connection of threads 35 of filter cap
80 with threads 25 on the neck of bottle 20 (FIG. 2). Plunger 90
is maintained by spring 57 in the highest vertical position permitted.
As plunger 90 incrementally rotates during water dispensing, projection
93b moves within opposing teeth 81 82 which are off-set and angled
to induce this rotation. (This continues until retaining tab 93a
reaches locking window 84. Upon locking, which is further discussed
below, plunger 90 is locked at a vertical level such that the plunger
covers threads 35 and interferes with engagement of the threads
by a water bottle.
[0060] Referring to FIGS. 13-16 "lead-in" angled surfaces
93a.sub.1 and 84a of retaining tab 93a and locking window 84 respectively,
are provided. These surfaces are angled to allow the locking tab
to cam its way onto the inside surfaces of window "frame"
84a as a result of the rotation of plunger 90 during the last few
iterative movements of projection 93b between teeth 81 82 just
prior to the locking of tab 93 within window 84. This camming action
flexes leg 93 toward the filter throat until retaining tab 93a clears
ramped surface 84a and enters the window itself.
[0061] The locking mechanism is also designed to reduce the risk
of losing the locking function, as now described. Referring to FIG.
16 if the user tries to connect the bottle threads to filter shutoff
device 30 after the locking mechanism has been engaged (and, thus,
retaining tab 93a lies within locking window 84), a downward force
is exerted on plunger 90 by the water bottle end. This pushes retaining
tab 93a against the bottom surface 84b of locking window 84. Bottom
surface 84b and the adjacent bottom surface of locking tab 93a are
each angled slightly in a downward direction moving away from filter
throat 91a. This results in locking tab 93a having a tendency to
"bury" itself deeper into locking window 84 rather than
trying to slide back toward the filter throat and losing engagement
with the locking window.
[0062] Referring to FIGS. 9 and 11 opening 85 is provided as a
relief, to ensure that projections 93b on the plunger do not shear
off as the plunger is installed. In addition, opening 85 provides
a visual indication to the installer, giving the installer the ability
to choose the number of iterations necessary before lock-up of the
filter occurs. For example, in the device shown in FIG. 11 fifty
teeth 81 82 and three openings 85 are provided about the inner
circumference of cap 80. The positions of openings 85 allow a design
in which, by initially locating the plunger so that projection 93b
is situated in an opening 85 filter shutoff device 30 can be configured
to provide any number of iterations necessary to correlate the volume
of bottles being used and the filter rating, and trigger filter
lock-up.
[0063] The openings of plunger 90 should be appropriately sized,
as now described. First, plunger top 92 is preferably provided with
a restricted circular throat 92a, to reduce water hammer through
the plunger. In the preferred embodiment, this opening has a diameter
of about 3/4 inches, which is 0.442 in.sup.2. Once the opening in
plunger top 92 is sized, the vertical slots in apron 91 of plunger
90 are then sized, by providing slots having an area such that the
effective surface area of the openings permitting water travel out
the side annular walls of plunger 90 is equal to the surface area
of throat opening 92a in plunger top surface 92.
[0064] Given this preferred plunger size and configuration, it
was found that water will fill the upper chamber of the filter,
i.e., above media retaining ring 33 and below cap 80 relatively
slowly, such that water will not be permitted to pass through vent
holes 120.
[0065] In a particularly preferred embodiment, an early warning
signal may be used to notify the user of the impending end of the
filter's useful life. For example, a red flag may be sprung into
position within the center of the filter when 90% of the filter's
useful life has expired. As another example, bi-colored icons or
a graduated bi-color band 191 (FIG. 12) may be used to indicate
that the useful life of the filter is nearing an end, by matching
dot or projection 190 on rotating plunger top surface 92 for example,
with band 191.
[0066] Filter cap 80 carrying opposed teeth 81 82 may be manufactured
by machining a collapsible core, such as those available from Detroit
Mold Engineering of Detroit, owned by Cincinnati Millicron (Catalog
No. CC-402-PC). When designing the teeth, a proper draft angle is
required to insure release from the molding surface. Each of the
teeth has a different shape depending on where they are located
on the collapsing core. The collapsing action of the DME core is
inward, or perpendicular to the primary draw angle of the mold,
and works with a specific number of pie shaped segments, as disclosed
in U.S. Pat. Nos. 3247548 and 3660001 incorporated herein by
reference. These pie shapes, usually consisting of twelve segments,
may have two different sizes, e.g., six large and six small. Each
segment should be machined separately.
[0067] Another aspect of the invention concerning vent holes 120
is now discussed. Referring to FIG. 3 when water bottle 20 is inverted
into a dispensing position, a seal is created between shutoff filter
rim 37 and bottle seat ledge 27a. To allow continuous dispensing
without lock-up, air passes from outside the filter through vent
holes 120 in filter cap 80 (FIG. 6), and into water bottle 20. When
the filter is initially installed on the bottle and the bottle is
rotated into the functioning position, during the time that water
flows down and wets and fills the filter media, the water flow path
that presents the least amount of resistance, and thus the path
the water actually travels, is through the vent holes. This is believed
due to a water hammer effect such that the existing air already
in the filter will tend to escape through these vent holes, carrying
water with it. This initial condition may result in some (less than
about 1 cc.) untreated water escaping through the vent holes and
into the treated water. This initial condition may result in a failure
to comply with NSF regulations regarding lead treatment, for example.
[0068] To solve this problem, a reduced throat diameter "D"
(FIG. 6) is provided, e.g., the throat diameter was reduced from
about 2 inches to about 3/4 inches, for example. In the preferred
embodiment, six vent holes 120 are provided on the upper surface
of filter cap 80 and pass completely through the filter cap. One
preferred size of the vent holes is about 0.031 inches; however
the vent holes may be sized larger, in which case fewer than six
may be used. Vent holes 120 permit air to escape from the filter,
and flow between the bottle threads and into the water bottle. Using
this restricted throat diameter, when water bottle 20 is inverted,
water slowly passes into filter shutoff device 30 such that the
water level in the device slowly rises. In a particularly preferred
embodiment, 0.7266 minutes was required for 3500 ml. of water to
flow through a filter shutoff device having a throat diameter of
about 3/4 inches (a fill rate of 4817 ml./min), whereas only 0.1728
minutes was required for the same volume of water to flow through
an identical filter with a throat diameter of about 1.5 inches (a
fill rate of 20255 ml./min). It was noted that water hammer continued
to cause water passage through the vent holes until the fill rate
was reduced below about 7500 ml./min. Unlike prior art designs,
even during the filling stage and before the water reaches its final
level within the filter due to the pressure head created by the
bottle neck, the water level never reaches above the level of vent
holes 120. With this design, then, water never flows out through
the vent holes, allowing NSF compliance, and reducing spillage and
mess.
[0069] Referring now to FIGS. 17-25 an alternative embodiment
of the filter shutoff device of the present invention, generally
referred to as 130 is shown. Referring first to FIG. 17 filter
cap 180 has opposed vertical walls 139 ending in tabs 139a designed
to removably snap into the opening formed by rim 141a of ring 141.
The outside walls 141b of ring 141 preferably taper, as shown, to
make room for this removable snap fit. A filter, not shown, is contained
within opening 152 created by this connection
[0070] Referring still to FIGS. 17-25 filter cap 180 is assembled
to a monitoring and locking device, generally referred to as 140
which consists of rotary indexing ring 141 and stationary ring 143.
Ring 141 includes a number of teeth 144a axially spaced about the
upper internal periphery of the ring, and a flexible or spring-loaded
tab 145 positioned along the outside edge of ring 141 having a
distal end 145a and a function described further below. Ring 143
includes a curved annular disc 144 with two curved springs 146
which may be helically-shaped, opposing tabs 148 on the ring periphery,
and two opposed indexing tabs 147. Indexing tabs 147 each have triangular
projections 147a, 147b, preferably shaped as shown.
[0071] Referring now to FIGS. 23-25 during normal water dispensing
and operation of the filter, teeth 144a are positioned as shown
in FIG. 23. Each time filter shutoff device 130 is removed from
an empty water bottle 20 and threaded to a new water bottle, device
140 is shaped, sized and configured to provide an rotary indexing
movement such that tab 147 is advanced in a counter-clockwise direction
(as seen when looking downward on device 130) the distance of one
tooth, as now explained. Each time device 130 is removed from an
empty water bottle, ring 143 is forced upward by springs 146 causing
two adjacent teeth 144a to be positioned adjacent triangular projection
147b, as shown in FIG. 24. The interaction of the leading tooth
144a.sub.1 against projection 147b causes an incremental counter-clockwise
rotation of ring 144 and indexing tab 147 (when viewing device 130
from a downward direction). Then, when a new water bottle is threadably
attached to device, 130 ring 143 is forced in a downward direction
by the neck of the bottle. When this occurs, indexing tab 147b moves
downward as well so that leading tooth 144a.sub.1 now contacts projection
147a, causing another incremental counter-clockwise rotation of
ring 144 and indexing tab 147 as shown in FIG. 25 such that trailing
tooth 144a.sub.2 is in the position that leading tooth 144a.sub.1
of FIG. 23 previously occupied.
[0072] In this manner, ring 143 is continued to be advanced in
a rotary direction until the disassembly of device 130 from an empty
water bottle causes spring-loaded tab 145 to reach opening 150 in
vertical wall 139 of filter cap 180. Now, distal edge 145a, which
was earlier prevented from doing so (see FIG. 18), enters opening
150 and halts further rotary movement of ring 143 and indexing tab
147 as shown in FIGS. 19-20. When this occurs, device 130 can no
longer be threadably connected to a new water bottle since the presence
of distal end 145a within opening 150 prevents downward movement
of ring 143 so that ring 143 remains in a position that covers
internal threads 135 of filter cap 180 as shown in FIG. 20.
[0073] As will now be understood, the components of filter monitoring
and locking device 140 may be shaped and oriented such that the
number of teeth used corresponds to the number of bottles which
may be used before the filter is disabled. For example, if 45 teeth
are used for 3-gallon bottles, then the filter disable device will
activate after 135 gallons of water have been used.
[0074] In an alternative preferred embodiment, shown in FIGS. 26-28
filter monitoring and locking device 240 is of one-piece construction,
and includes a single molded component consisting of upper ring
243 and lower ring 241. Indexing tab 247 extends down from ring
244 and includes an upper opening 247c with a pointed tab 245. Indexing
tab 247 also includes a lower, stepped series of openings 247d.
In a similar manner as described above, ring 243 and tab 247 are
rotary indexed in a counter-clockwise direction (again, when viewing
device 240 from above) by the stepped orientation and interaction
of openings 247d with teeth 244a, as shown in FIGS. 26 and 28. As
the filter shutoff device is used, removed and then connected to
a new water container, tab 247 rotates and pointed tab 245 moves
within succeeding angled openings 260. When tab 247 reaches a position
permitting the entry of tab 245 into opening 270 on ring 241 (FIG.
27), further rotary movement of ring 243 ceases, disabling the filter
shutoff device by preventing its threaded connection with water
container 20.
[0075] It will be understood that the filter shutoff device of
the present invention may be used with water containers other than
the inverted water bottles shown in the drawings. For example, the
device may be used with water pitchers or sports bottles. It will
also be understood that the filter shutoff device may be used with
a variety of water dispensing devices, and a variety of filters,
other than those specifically described here.
[0076] While the invention has been described with reference to
a threaded connection between filter shutoff device 30 and water
bottle 20 it will be understood that device 30 may be modified
for use with water containers that are not intended to be threadably
connected to device 30. For example, filter shutoff device 30 could
be used with non-threaded connections between device 30 and water
bottle 20 such as those described in U.S. Pat. Nos. 5222531 and
5289855 incorporated herein by reference, such that a cap could
be press-fit onto the filter device. As another example, instead
of both the water container and the filter shutoff device having
threads, one could have a partial thread and the other a simple
projection that would engage the partial thread when the filter
shutoff device is rotated; this could act as a helical ramp for
the projection, pulling the two components tightly together.
[0077] The above description is not intended to limit the meaning
of the words used in the following claims that define the invention.
Rather, it is contemplated that future modifications in structure,
function or result will exist that are not substantial changes and
that all such insubstantial changes are intended to be covered by
the claims. |