Title: Portable liquid dispensers
Abstract: A battery operated self-contained submersible liquid dispenser for dispensing discrete quantities of a liquid from a remote liquid reservoir is provided. The dispenser comprises a hermetically sealed walled housing containing a peristaltic pump driven either directly or via a speed reduction gear train by an electric motor in response to motor activation signals received from an electric control circuit within the housing. The pump includes a flexible liquid dispensing tube connected to respective liquid inlet and liquid outlet ports extending through the wall of the housing, a pump actuator for forcing liquid received via the liquid inlet port through the tube to the outlet port, and a sensor on or in the wall of the housing connected to the circuit. The sensor is adapted to sense a changed condition from a required parameter external to the housing, e.g., such as the presence or absence of water, the circuit thereafter activating the motor and hence the pump to dispense a discrete quantity of the liquid
Patent Number: 6,993,795 Issued on 02/07/2006 to Prineppi
| Inventors:
|
Prineppi; Frank Joseph (PMB 341, 1323 SE. 17th St., Fort Lauderdale, FL 33316)
|
| Assignee:
|
Prineppi; Frank Joseph (Ft. Lauderdale, FL)
|
| Appl. No.:
|
754122 |
| Filed:
|
January 9, 2004 |
| Current U.S. Class: |
4/227.1; 417/411; 417/477.1 |
| Current Intern'l Class: |
E03D 9/02 (20060101) |
| Field of Search: |
4/222
417/411,477.1,902,36
222/64
|
References Cited [Referenced By]
U.S. Patent Documents
Primary Examiner: Phillips; Charles E.
Attorney, Agent or Firm: Stockwell and Associates
Claims
What is claimed is:
1. A battery operated self-contained submersible liquid dispenser for dispensing
discrete quantities of a liquid from a remote liquid reservoir, the dispenser comprising
a hermetically sealed walled housing containing therein a peristaltic pump driven
either directly or via a speed reduction gear train by an electric motor in response
to motor activation signals received from an electric control circuit within the
housing, the pump including a flexible liquid dispensing tube connected to respective
liquid inlet and liquid outlet ports extending through the wall of the housing,
a pump actuator for forcing liquid received via the liquid inlet port through the
tube to the outlet port, and a sensor on or in the wall of the housing connected
to the circuit, the sensor being adapted to sense a changed condition from a required
parameter external to the housing, the circuit thereafter activating the motor
and hence the pump to dispense a discrete quantity of the liquid.
2. A dispenser according to claim 1, wherein the sensor comprises a pair of electrodes
and the changed condition comprises a change in electrical resistivity between
the electrodes.
3. A dispenser according to claim 1, wherein the sensor comprises a pair of electrodes
and the changed condition comprises detecting the presence or absence of water
between the electrodes.
4. A dispenser according to claim 3, wherein the sensor is adapted to detect
the presence or absence of water within a toilet cistern such that when the cistern
is full, the sensor detects the presence of water within the cistern or when the
toilet is flushed the sensor detects the absence of water within the cistern.
5. A dispenser according to claim 1, wherein a microprocessor is contained within
said electric control circuit, and is programmable by means of an external signal.
6. A dispenser according to claim 5, wherein the microprocessor is programmed
via a keyboard mounted on or in the wall of the housing and connected to the microprocessor.
7. A dispenser according to claim 5, wherein the microprocessor further comprises
a timer circuit for activating the motor and hence the pump for a preset duration
corresponding to a required rate and hence a pre-selected quantity of the liquid
to be dispensed.
8. A dispenser according to claim 1, wherein the actuator comprises a spoked
wheel having a plurality of radially disposed spokes each having a free end and
driven either directly or indirectly via the motor, the free ends of a respective
adjacent pair of spokes being adapted to bear directly or indirectly onto a predetermined
section of the tube to thereby trap therebetween a bolus of liquid to be dispensed
via the outlet port, the spokes being further adapted to push the bolus progressively
through the tube and out of the outlet port as the wheel rotates in response to
the urging of the motor.
9. A dispenser according to claim 1, wherein the actuator comprises a spoked
wheel having a plurality of radially disposed spokes each having a free and driven
either directly or indirectly via the motor, the free ends of a respective adjacent
pair of spokes being adapted to bear directly or indirectly onto a pre-determined
section of the tube to thereby trap there between a bolus of liquid to be dispensed
via the outlet port and the spokes being further adapted to push the bolus progressively
through the tube and out of the outlet port as the wheel rotates in response to
the urging of the motor, and whereas the end of each spoke further includes a roller
so as to minimize wear and tear on the outside of the tube in this region and to
reduce friction, the rollers "pinching" the walls of the tube flat as they roll
over the tube.
10. A dispenser according to claim 1, programmed to dispense a preselected quantity
of the liquid repeatedly at timed intervals, subject to the condition sensed by
the sensor indicating a required parameter.
11. A dispenser according to claim 1, wherein the condition sensed by the sensor
is the presence or absence of a fluid having a pre-determined characteristic.
12. A dispenser according to claim 11, wherein the fluid is water.
13. A dispenser according to claim 12, wherein the fluid is water and the predetermined
characteristic is selected from the group consisting of a desired pH, a desired
electrolytic content, and an undesirable pathogen.
14. The dispenser according to claim 12, wherein the fluid is air and the predetermined
characteristic is a desired humidity.
15. A dispenser according to claim 1, wherein the control circuit is pre-programmed
during manufacture to perform required tasks and the battery is built into the
housing before it is hermetically sealed, thereby making the dispenser relatively
cheap to make such that it may simply be a disposable item once the battery has
been exhausted.
16. A dispenser according to claim 1, further comprising means for preventing
backflow of the liquid within the tube such that entry of a fluid at the outlet
port is substantially prevented.
17. The dispenser according to claim 16, wherein the means for preventing backflow
of the liquid within the tube comprises configuration of the speed reduction gear
train the permit rotation of the pump actuator in a single direction.
18. The dispenser according to claim 17, wherein the speed reduction gear train
comprises a drive shaft connected to the motor, a first worm gear connected to
the drive shaft to drive a first spur gear mounted for rotation with a second worm
gear in mesh with a second gear mounted for rotation with the pump actuator, such
that rotation of the actuator is effectively permitted to occur in a single direction.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of priority in prior UK Patent Application
Serial Number: 0314887.1, filed on Jun. 26, 2003
1. Field of the Invention
This invention relates to portable liquid dispensers of the type including a
power source, a pump and a motor for driving the pump, all contained within a single
housing and operable to selectively dispense a discrete quantity of a liquid
2. Backgroud of the Invention
Portable liquid dispensers are known for dispensing, e.g., medicines, such
as insulin, into the body of a recipient, and a system for achieving this is disclosed
in U.S. Pat. No. 5,429,602, the disclosure of which is incorporated herein by reference.
In that prior art device, a programmable microprocessor is used to perform one
or more control functions via the use of a keyboard or similar or automatically
via, e.g., a card reader or from an external source via a modem. The present invention
is derived from the realisation that such dispenser technology may be adapted to
different uses so as to perform tasks that would otherwise be carried out in conventional
but substantially different ways.
SUMMARY OF INVENTION
According to a first aspect of the invention there is provided a battery
operated self-contained submersible liquid dispenser for selectively dispensing
discrete or pre-selected quantities of a liquid from a remote liquid reservoir.
The dispenser comprises a hermetically sealed walled housing containing a peristaltic
pump driven either directly or via a speed reduction gear train by an electric
motor in response to motor activation signals received from an electric control
circuit within the housing. The pump includes a flexible liquid dispensing tube
connected to respective liquid inlet and liquid outlet ports extending through
the wall of the housing and a pump actuator for forcing liquid received via the
liquid inlet port through the tube to the outlet port. A sensor is located on or
in the wall of the housing and is connected to the circuit, the sensor being adapted
to sense a changed condition from a required parameter external to the housing,
e.g., such as the presence or absence of a fluid such as air or water, the circuit
thereafter activating the motor and hence the pump to selectively dispense a discrete
or pre-selected quantity of the liquid.
With this arrangement, the liquid dispenser may e.g. be connected via the inlet
port to a reservoir of the liquid, e.g., such as a cleaning liquid for cleaning
the bowl of a toilet. The housing may ordinarily be submerged near to the top of
the toilet cistern such that when a changed condition arises, i.e., the absence
of water at the sensor due to the toilet being flushed, a discrete amount of the
cleaning liquid may then be discharged into the cistern, either immediately or
at some timed interval thereafter, or when the cistern fills up again.
The sensor may conveniently comprise a pair of electrodes, between which a change
in electrical resistivity may be sensed as the water is discharged from the cistern
when the toilet is flushed.
Conveniently, the microprocessor is programmable by means of external
signals, such as through a keyboard mounted on or in the wall of the housing. The
microprocessor may also include a timer circuit for activating the motor and hence
the pump for a preset duration corresponding to a required rate and hence pre-selected
quantity of liquid to be dispensed.
The actuator may conveniently comprise a spoked wheel comprised of a plurality
of radially disposed spokes having free ends, the wheel being driven either directly
or indirectly via the motor. The free ends of respective adjacent pairs of spokes
are adapted to bear directly or indirectly onto the tube at a pre-determined section
of the tube to thereby trap therein and between the adjacent spokes a bolus of
liquid to be dispensed via the outlet port. As the wheel rotates in response to
urging by the motor, the free ends of the spokes push the bolus progressively through
the tube and out of the outlet port. In an improvement to this concept, the end
of each spoke includes a roller so as to minimize wear and tear on the outside
of the tube in this region and to reduce friction, the rollers "pinching" the walls
of the tube flat as they roll over the tube.
In a second aspect of the invention, the liquid dispenser is programmed to dispense
liquid repeatedly at timed intervals, subject to the condition sensed by the sensor
indicating a required parameter, e.g., such as if the housing is submersed in a
liquid or not. This embodiment finds particularly advantageous use as a dispenser
for dispensing liquid chemicals at regular intervals into, e.g., a swimming pool
where, if the sensed condition outside of the housing is dry, no liquid is dispensed,
but if the dispenser is submerged, e.g., resting at the bottom of the swimming
pool, liquid chemicals such as chlorine, salt, etc. may be dispensed at regular
intervals, the sensor or another sensor continually monitoring a required parameter
of the swimming pool, such as its pH, salinity, etc.
Other applications for the liquid dispenser of the invention may also be found
such as, e.g., an automatic fragrance/deodorizer dispenser, a consumer-programmed
automatic plant feeder, and a fish-tan algaecide dispenser in which the user can
set up the desired operating interval between delivery and hence make the volume
adjustable to thereby deliver a well metered infusion into the fish tank.
In a further refinement, the control circuit may be pre-programmed during manufacture
to perform required tasks and the battery may be built into the housing before
it is hermetically sealed, thereby making the dispenser relatively cheap to make
such that it may simply be a disposable item once the battery has been exhausted.
The invention will now be described, by way of example only, with reference to
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a liquid dispenser in accordance with
first and second aspects of the invention,
FIG. 2 is a sectional elevation of the liquid dispenser of FIG. 1 showing its
internal components,
FIG. 3 is a sectional elevation of part of the dispenser of FIG. 1,
FIG. 4 is a schematic circuit diagram showing how the invention works in accordance
with a first embodiment, and
FIG. 5 is a schematic circuit diagram showing how the invention works in accordance
with a second embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring firstly to FIGS. 1 to 3, which show the mechanical arrangement
of a liquid dispenser, an hermetically sealed walled housing
1 of part-cylindrical
shape contains a motor
2, drivingly connected to a double worm wheel and
spur gear speed reduction arrangement shown generally at
3 to a rotatable
actuator
4 of a peristaltic pump mechanism shown generally at
5.
A pair of batteries
6 (shown in outline only in FIG. 2) provide electric
power for the motor
2, a printed circuit board
7 connected to it
and to a sensor in the form of a pair of electrodes
8 extending through
the housing
1.
As can be seen more clearly with reference to FIG. 3, the peristaltic pump mechanism
also includes a flexible tube
9, such as of silicone, which bears against
the part cylindrical inner wall
1a of the housing
1 and each
end thereof is connected to respective inlet and outlet ports in the shape of spigots
10,
11 to allow liquid within the tube
9 to be drawn into
it via the inlet port
10 and expelled via the outlet port
11.
The pump actuator
4 has four radially disposed spokes or arms
12
carrying respective rollers
13 which bear against the flexible tube
9
such that upon rotation of the actuator in the direction arrowed adjacent pairs
of rollers
13 trap therebetween, in use, a bolus of liquid until such is
forced out through the outlet port
11 but without such liquid ever entering
the hermetically sealed interior of the housing
1 other than to pass through
the tube
9.
As will be appreciated, because the actuator
4 is connected to the drive
shaft of the motor
2 via the worm and spur gear speed reduction arrangement
3, using a worm gear connected to the drive shaft of the motor to drive
a spur gear mounted for rotation with another worm gear in mesh with a second spur
gear mounted for rotation with the actuator
4, the combined effect of the
gearing means that rotation in the opposite direction of the actuator
4
is effectively impossible so that the combination of gearing and actuator
3
essentially acts as a one way valve mechanism for the tube
9 which, in turn,
ensures that liquid pushed out of the tube
9 through the outlet port
11
cannot thereafter return. Also, when the motor
2 stops the actuator
4
effectively locks-up such that, depending upon its rotational position within the
housing
1, there are always at least two spokes
12 and respective
rollers
13 pressing against the outer wall of the tube
9 to prevent
escape or ingress of liquid from or to the reservoir (not shown) to which the inlet
port
10 of the dispenser is attached. Such reservoir may conveniently be
vented to allow ingress of air and hence escape of liquid when the pump
5
is activated by the motor
2, or the reservoir may be collapsible, the torque
generated by the motor
2 and drive train
5 being sufficient to cause
the liquid in the reservoir to be sucked out of it until empty.
Turning now to FIG. 4, there is shown a schematic circuit diagram showing
how a first embodiment of the invention operates. In this embodiment the liquid
dispenser produces a single pumping cycle per activation when an activation event
occurs which is detected by the electrodes
8. This could typically be a
change from a wet state corresponding to the electrodes being submerged, such as
in a toilet cistern, to a dry state when the cistern has been flushed, at which
point a metered infusion of e.g. a disinfectant is then released into the cistern
when a change in electrical resistivity is detected between the electrodes
8.
This change is detected by the electrodes
8 and the signal is then amplified
and processed via an amplifier and signal conditioner circuit
14 which produces
a single pulse "A" which activates a duration time circuit
15 for determining
how long a motor driver circuit
16 activates the motor
2 and hence
the peristaltic pump
5. The duration timer
15 may be factory preset
through the use of attendant jumper straps shown generally at
17, although
it will be understood that other timing circuits may be used, such as through the
use of a decade switchbank or even a simple analogue R-C timing circuit. The embodiment
shown in FIG. 4 is, however, particularly simple to adopt and lends itself to mass
production and hence relatively inexpensive manufacture aimed especially but not
necessarily, at the disposable market.
Turning now to the more sophisticated circuit shown in FIG. 5, this can be
used to provide activation of the motor
2 and hence pump
5 at regular
intervals via a separate pre-set interval timer circuit
18 connected via
and gate
19. This circuit is designed for use when the electrodes
8
are normally submerged, such as where the liquid dispenser is for dispensing liquid
chemicals at regular intervals in e.g. a swimming pool. The amplifier and signal
conditioner circuit
14a provide a steady state signal "B" to the
gate
19 to signal the electrodes
8 are submerged and at regular intervals,
pre-set via the jumper straps
17a, a "duration elapsed" pulse is
then sent to the second input terminal of the gate
19, producing a signal
in combination with the steady state signal from the amplifier and signal conditioner
14a which triggers the duration timer
15 which, in turn, operates
the motor driver circuit
16 and hence motor
2 for the duration specified
by the pre-set jumper straps
17. If the electrodes
8 are taken out
the water the change of resistivity is sensed by the amplifier and signal conditioner
14a which then shuts off the steady state signal until the electrodes
8 are submerged again, effectively switching off the circuit, the programmable
interval timer
18 thereafter being unable to send a signal to the duration
timer
15 through the gate
19. Again, it will be appreciated that
the duration timer
15 and programmable interval timer
18 may use
instead of jumper straps
17,
17a, e.g., a decade switchbank
or a simple analogue R-C timing circuit.
Reverting to FIG. 1, it is envisaged that, depending upon the sophistication
of the circuitry and the intended use of the liquid dispenser, digital readout
may be provided via a digital display facility
20 using, e.g., an LCD readout,
some or all of the circuits may be externally programmable through the use of a
keypad
21 and a mode select function
22 may also be used, particularly
where, e.g., the liquid dispenser is to be used in variable circumstances, such
as in horticulture for, e.g., slow release of fertiliser to suit the particular
circumstances in terms of location, type of plant and ambient conditions.
Because the liquid dispenser uses a peristaltic pump it can be manufactured
as a hermetically sealed unit which, as aforesaid, lends itself to the mass market
and a multitude of uses where accurate liquid metering is required in response
to or dependent upon a sensed condition as described above. A further advantage
of using a peristaltic pump is that it is able to self-prime and can be used submerged
in another liquid whilst at the same time resisting back-flow leakage. Hence, highly
concentrated liquids to be dispensed by the device, which would or could cause
environmental or other problems to occur in the event of too great a dose being
allowed into the environment, can still be safely connected upstream of the pump
without the need for separate control valves or taps.
*
