Information
-
Patent Grant
-
6386390
-
Patent Number
6,386,390
-
Date Filed
Wednesday, December 1, 199924 years ago
-
Date Issued
Tuesday, May 14, 200222 years ago
-
Inventors
-
-
Examiners
- Shaver; Kevin
- Buechner; Patrick
Agents
- Durando; Antonio R.
- Durando Birdwell & Janke, P.L.C.
-
CPC
-
US Classifications
Field of Search
US
- 222 52
- 222 4815
- 222 1813
- 222 571
- 250 221
-
International Classifications
-
Abstract
A dispenser has a container for a liquid, a vent opening to allow air into the container, a valve to control the admission of air into the container, and a dispensing opening for the liquid to be dispensed therefrom. The dispenser is mounted with the dispensing opening at the bottom. When the valve is closed, a pressure differential is created that prevents the liquid in the container from flowing out. Upon opening of the vent valve, the pressure differential is reduced and dispensing can continue. Such a dispenser can be used to dispense fluids of varying viscosities and even nonporous solids. In one embodiment of the invention, an infrared radiation emitter and an infrared radiation detector are arranged in such a manner that, when a hand is placed below the dispenser, radiation from the emitter impinges on the hand and is reflected to the detector. Upon sensing the reflected radiation, the detector causes the valve for the vent tube to open so that the pressure differential in the container is eliminated and the liquid can be dispensed. When the hand is withdrawn, the detector no longer senses radiation from the emitter and causes the valve for the vent tube to close reestablishing the pressure differential that stops the outflow of liquid. The dispensing opening is preferably in the form of an S-shaped tube to prevent dripping of the liquid, such as soap, when the valve is closed.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a dispenser for flowable soap.
2. Description of the Prior Art
Most dispensers for flowable soap are currently manually operated, which means that the dispenser must be touched when soap is to be dispensed. Since it is unsanitary to touch the dispenser, it would be desirable to be able to obtain soap without touching the dispenser.
Accordingly, several automatic dispensers have been developed employing two distinct principles for delivering fluid from a reservoir. The first technique makes use of a pump, which can be solenoid operated, rotating-cam operated, or actuated by deformation of a flexible reservoir. Pumps are inefficient in this type of application because any change in the kinetic or potential energy of the fluid must be provided by the electrical source energizing the pump.
More efficient devices use gravity to provide the force necessary to move the liquid. Accordingly, another technique is to position an electrically actuated valve below the fluid reservoir. When the valve is opened, the fluid is forced through it by gravity. This design is necessarily inefficient because the aperture size of the valve must be adapted as a function of the viscosity of the fluid that must flow through it. Thus, larger apertures require more energy to open them. Therefore, a more efficient automatic-dispenser design would be desirable for reasons of economics and energy conservation.
SUMMARY OF THE INVENTION
It is an object of the invention to eliminate the need for touching a dispenser in order to dispense a liquid such as soap therefrom.
Another objective of the invention is a design for an automatic dispenser that is suitable for liquids of various viscosities.
Another goal is a dispenser that utilizes gravity as the motive force for the liquid being dispensed.
Still another goal is a dispenser that operates with increased efficiency regardless of the viscosity of the liquid being dispensed.
Another objective is a design that can be implemented efficiently and economically.
Still another object is a dispenser that prevents dripping of the dispensed liquid between uses.
The preceding objects, as well as others which will become apparent as the description proceeds, are achieved by the invention.
One aspect of the invention resides in a dispenser for a liquid, such as liquid soap. The dispenser comprises a container for a supply of soap, and the container is provided with at least one opening for discharging soap therefrom. The dispenser further comprises means for detecting objects at a spacing from the container, and means for controlling the passage of soap through the discharging opening. The controlling means has a first condition in which soap is free to pass through the discharging opening and a second condition in which the passage of soap through the opening is inhibited. The controlling means is designed to assume the first condition in response to the detection of an object by the detecting means and to revert to the second condition in response to discontinued detection of the object. The detecting means can detect a hand which is spaced from the dispenser and is designed so that soap is dispensed when a hand is detected. Hence, the dispenser in accordance with the invention makes it unnecessary to touch the dispenser in order to obtain soap therefrom.
According to another aspect of the invention, the dispenser consists of a closed reservoir having a dispensing opening at its lower extremity through which the liquid can flow. As the fluid flows out of the reservoir through the opening, the pressure at the top in the reservoir is gradually reduced until the pressure differential between the inner top portion of the reservoir and the ambient, external atmospheric pressure is sufficient to stop the flow of fluid. An electrically actuated valve is positioned to admit air from outside the reservoir into the upper, low pressure, area of the reservoir to allow the fluid to flow from the reservoir through the lower opening.
Another aspect of the invention resides in a method of operating a soap dispenser. The method comprises the steps of placing an object at a predetermined location spaced from the dispenser, sensing the object while the object is at such location, and dispensing soap from the dispenser in response to the sensing step. The sensing step may include detecting energy reflected from the object, and the energy can comprise infrared radiation. The method can further comprise the steps of removing the object from the predetermined location, discontinuing the sensing step upon removal of the object from this location, and terminating the dispensing step in response to discontinuation of the sensing step.
The method may also comprise the step of inhibiting the dripping of soap from the dispenser subsequent to the terminating step. The dispenser can include a soap container and a supply of soap in the container, and the dispensing step may involve establishing communication between the soap supply and the atmosphere.
Additional features and advantages of the invention will be forthcoming from the following detailed description of preferred embodiments when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a schematic view of a dispenser according to the preferred embodiment of the invention.
FIG. 2
is a perspective view of a soap dispenser according to the invention in a holder.
FIG. 3
is a partly sectional perspective view of a soap reservoir constituting part of the soap dispenser of FIG.
2
.
FIG. 4
is a partially cut-out, enlarged perspective view of a cap constituting part of the soap dispenser of FIG.
2
.
FIG. 5
is a block diagram of circuitry for operating the soap dispenser of FIG.
2
.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, wherein like parts are designated throughout with like numerals and symbols,
FIG. 1
illustrates schematically a rigid reservoir
10
constructed with an opening
12
at the bottom and a sealed removable top
14
. The top is fitted with a small hose barb
16
that is connected to a valve
18
by a small tube
20
to admit air into the upper portion
22
of the reservoir. The opening
12
in the bottom of the reservoir
10
is preferably threaded to allow various dispensing nozzles, such as the S-shaped nozzle
24
, to be removably attached. The shape of the nozzle
24
is provided to inhibit post-dispense dripping as well as dripping due to atmospheric pressure variations.
The valve
18
is preferably a normally-closed miniature valve, such as the Clippard EE3-TL-12 Double E-3 Subminiature Electronic Valve made by Clippard Instrument Laboratory, Inc., of Cincinnati, Ohio. When open, the valve
18
admits air into the upper portion
22
of the reservoir, thereby allowing fluid in the reservoir to flow through the opening
12
and the nozzle
24
. As well understood in the art, the dispensing nozzle
24
can be constructed in a variety of internal diameters to achieve equal dispensing volumes for liquids with different viscosities. For a target dispensing time period and a given liquid volume in the reservoir, a variation in the kinematic viscosity of the liquid can be accounted for by the known relationship D
1
/D
2
=[v
1
/v
2
]
¼
, where v
1
and v
2
are the kinematic viscosities of two alternative liquids and D
1
and D
2
are corresponding internal diameters for the dispensing nozzle. See Fox et al.,
Introduction to Fluid Mechanics
, Wiley & Sons (1985).
Upon receiving a dispense signal, the valve
18
is opened to admit air into the upper reservoir cavity
22
. In response, the liquid
26
contained in it begins to flow through the opening
12
and the dispensing nozzle
24
. The kinetic energy of the flowing liquid causes the upper reservoir cavity
22
to “overshoot” the equilibrium pressure differential required to just balance the liquid depth to stop the flow. Thus, the excess pressure differential causes the liquid to be “sucked back” into the reservoir such that the equilibrium position of the liquid-air interface
28
in the nozzle is drawn to the intermediate section of the S-shaped tube in the dispensing nozzle. It is understood that for the dispenser to drip, the liquid-air interface
28
would need to be in the outer section
30
of the tube in dispensing nozzle, which is no longer the case. Therefore, the combination of the nozzle design and the vacuum-controlled release of the liquid effectively prevents dripping when the valve
18
is closed. Similarly, atmospheric-pressure changes can cause the migration of the liquid-air interface
28
along the tube of the dispensing nozzle, but the dispenser can tolerate atmospheric-pressure reductions equal to the liquid head separating the current height of the interface
28
from the top of the intermediate section of the S-shaped tube in the nozzle
24
, as would be clearly understood by one skilled in the art.
Referring to
FIG. 2
, the numeral
110
identifies another embodiment of an automatic dispenser in accordance with the invention. The dispenser
110
is designed to dispense liquid soap in a flowable form and is especially well-adapted for that application. The soap dispenser
110
comprises a container
112
for holding a supply of soap. The container
112
includes a generally frustoconical reservoir or body
114
and a cover
116
which is removably mounted on one axial end of the reservoir
114
. The cover
116
can, for instance, be screwed onto the reservoir
114
, be a press fit on the reservoir or be held on the reservoir by suitable fasteners, such as screws. The soap dispenser
110
further comprises a lower cap or housing
118
which is removably mounted on the axial end of the reservoir
114
remote from the cover
116
. Similarly to the cover
116
, the cap
118
can, for example, be screwed onto, press fit, or held on the reservoir
114
by suitable fasteners.
FIG. 2
shows the soap dispenser
110
being supported in a holder
120
. The holder
120
includes a ring
122
having an inner diameter smaller than the maximum outer diameter of the reservoir
114
so that the reservoir can rest on the ring
122
when inserted in the latter. The holder
120
further includes a shank
124
which extends radially outward from the ring
122
and serves as a mounting element for the holder
120
. Thus, the shank
124
allows the holder
120
to be affixed to a surface such as a wall surface. The reservoir
114
accommodates a supply or body of soap
126
. Between the soap
126
and the cover
116
is an empty space
128
which is essentially airtight.
Turning to
FIG. 3
, the end of the reservoir
114
remote from the cover
116
is closed by a wall
130
which separates the interior of the reservoir
114
from the interior of the cap
118
. The wall
130
is provided with an opening
132
through which the soap
126
can be discharged from the reservoir
114
. The wall
130
is provided with a second opening
134
which is spaced from the discharging opening
132
. A vent tube
136
passes through the opening
134
and extends through the reservoir
114
as well as through the cap
118
. The vent tube
136
has opposite longitudinal ends
136
a
and
136
b
which are provided with apertures so that the vent tube
136
is open at either longitudinal end
136
a
,
136
b
. The longitudinal end
136
a
is located in the empty space
128
of the container
112
, and a check valve
138
is mounted in the longitudinal end
136
a
. The check valve
138
prevents the soap
126
from flowing into the vent tube
136
if the container
112
should be tilted.
Considering the enlarged view of
FIG. 4
, a valve
140
is mounted inside the cap
118
at the longitudinal end
136
b
of the vent tube
136
. The valve
140
is preferably a miniature valve such as described above. The valve
140
has an open condition or open position in which the valve establishes communication between the interior of the vent tube
136
and the atmosphere. The valve
140
also has a closed condition or closed position in which the interior of the vent tube
136
is sealed from the atmosphere.
In the open condition of the valve
140
, the space
128
in the container
112
communicates with the atmosphere by way of the vent tube
136
and is at atmospheric pressure. The soap
126
is then free to flow out of the container
112
via the discharging opening
132
. When the valve
140
is subsequently placed in the closed condition, a vacuum is produced in the space
128
and causes the soap
126
to stop flowing out of the container
112
. The vent tube
136
and valve
140
can thus be considered to constitute a means for controlling the passage of the soap
126
through the discharging opening
132
.
The cap
118
is provided with a central opening
142
. A tubular member
144
extends between the cap opening
142
and the discharging opening
132
of the reservoir
114
. The tubular member
144
establishes a flow path for the soap
126
from the reservoir
114
to the cap opening
142
. The cap opening
142
constitutes a dispensing opening through which the soap
126
is dispensed from the soap dispenser
110
. As in the embodiment of
FIG. 1
, the tubular member
144
is designed to inhibit or prevent the dripping of soap from the dispenser
110
. To this end, it is preferred for the tubular member
144
to have a generally S-shaped configuration as shown. Thus, the tubular member
144
includes a straight section
144
a
extending from the dispensing opening
142
, a straight section
144
b
extending from the discharging opening
132
, and a curved section
144
c
connecting the straight sections
144
a
,
144
b
to one another. The curved section
144
c
defines a depression between the straight sections
144
a
,
144
b.
Also mounted in the cap
118
are an energy emitter
148
and an energy detector
150
. The energy emitter
148
is arranged to direct energy to a location which faces the dispensing opening
142
in the cap
118
and is spaced from the cap
118
. On the other hand, the energy detector
150
is arranged to detect energy reflected from an object at such location. The energy detector
150
is designed to detect energy having the same frequency or frequency range as the energy emitted by the energy emitter
148
.
The cap
118
, or at least the portions of the cap
118
adjacent to the energy emitter
148
and the energy detector
150
, are transparent to the energy emitted by the energy emitter
148
. Hence, the cap
118
does not interfere with the transmission of energy emitted by the energy emitter
148
. The energy emitter
148
and the energy detector
150
are preferably designed to emit and detect infrared radiation. The energy emitter
148
and the energy detector
150
are spaced from one another, and a partition or wall
152
extends across the interior of the cap
118
between the energy emitter
148
and the energy detector
150
. The partition
152
separates the energy emitter
148
and the energy detector
150
from each other and is opaque to the energy emitted by the energy emitter
148
. The partition
152
prevents energy generated by the energy emitter
148
from reaching the energy detector
150
unless the energy has been reflected from an object which faces the dispensing opening
142
and is spaced from the cap
118
. Thus, the partition
152
prevents energy generated by the energy emitter
148
from traveling directly to the detector
150
. Likewise, the partition
152
prevents energy which is generated by the energy emitter
148
and then reflected by the cap
118
from reaching the energy detector
150
.
With reference to
FIG. 5
, the energy emitter
148
is driven by an oscillator
154
which functions as a clock. Thus, the oscillator
154
periodically sends a signal to the energy emitter
148
which thereupon generates an energy pulse having a predetermined frequency. The signals produced by the oscillator
154
also go to a coincidence and frequency discrimination unit
156
. The energy detector
150
is energized whenever the energy detector
150
senses energy having a frequency within a predetermined range. The energy detector
150
then generates output signals indicative of the frequency of the energy impinging upon the energy detector
150
. The signals produced by the energy detector
150
are sent to the discrimination unit
156
.
The discrimination unit
156
performs two main functions. On the one hand, the discrimination unit
156
determines whether the signals arriving from the energy detector
150
coincide with the signals arriving from the oscillator
154
. On the other hand, the discrimination unit
156
determines whether the energy sensed by the energy detector
150
has the same frequency as the energy emitted by the energy emitter
148
. If both conditions hold true, the discrimination unit
156
concludes that the energy detector
150
is sensing energy coming from the energy emitter
148
by reflection from an object near the dispensing opening
142
. The discrimination unit
156
then causes the valve
140
to assume its open condition. When the signals from the energy detector
150
cease, no longer coincide with the signals from the oscillator
154
, or no longer have the same frequency as the signals from the energy emitter
148
, the discrimination unit
156
causes the valve
140
to assume its closed condition. The oscillator
154
can be keyed to the discrimination unit
156
.
Referring back to
FIG. 4
, the valve
140
, energy emitter
148
, energy detector
150
, oscillator
154
and discrimination unit
156
are all fixed to a circuit board
158
removably mounted inside the cap
118
. The circuit board
158
runs circumferentially of the cap
118
and may be circumferentially complete. If the circuit board
158
is circumferentially complete, the circuit board
158
is provided with a central opening for the tubular member
144
. The circuit board
158
can, for example, have a generally annular configuration. Power for the valve
140
, energy emitter
148
, energy detector
150
, oscillator
154
and discrimination unit
156
is supplied by a small battery connected to the circuit board
158
.
The soap dispenser
110
is of the gravity-fed type as opposed to the pump type. Thus, with the soap dispenser
110
, gravity rather than a pumping action is used to discharge the soap
126
from the dispenser
110
.
One manner of operation of the dispenser
110
will be described assuming that the dispenser
110
is mounted on a wall in the upright position of FIG.
2
. It is further assumed that the energy emitter
148
emits infrared radiation and that the energy detector
150
is designed to sense infrared radiation. The energy emitter
148
periodically emits a pulse of infrared radiation having a predetermined frequency. The rate at which the pulses are generated is determined by the oscillator
154
which activates the energy emitter
148
at regular intervals and sends a signal to the discrimination unit
156
upon each activation. As long as no objects are placed below and in the vicinity of the dispensing opening
142
, the radiation pulses are dissipated and are not detected by the energy detector
150
. Consequently, the energy detector
150
sends no signals to the discrimination unit
156
which, in turn, causes the valve
140
to be in its closed condition. The space
128
above the soap
126
in the soap container
112
is cut off from the atmosphere and a vacuum exists in the space
128
. The vacuum prevents the soap
126
from flowing out of the reservoir
114
.
When a hand is placed below and within a predetermined distance of the dispensing opening
142
, the infrared radiation from the energy emitter
148
is at least partially reflected by the hand to the energy detector
150
. Upon sensing the reflected radiation, the energy detector
150
generates signals which are sent to the discrimination unit
156
. These signals are indicative of the frequency of the infrared radiation sensed by the energy detector
150
, and the discrimination unit
156
determines whether such frequency is the same as the frequency of the infrared radiation emitted by the energy emitter
148
. Furthermore, the discrimination unit
156
determines whether the signals generated by the oscillator
154
and the signals generated by the energy detector
150
arrive at the discrimination unit
156
at the same intervals. If the frequency of the infrared radiation detected by the energy detector
150
equals the frequency of the infrared radiation emitted by the energy emitter
148
and the signals from the oscillator
154
and the energy detector
150
are received at the same intervals, the discrimination unit
156
causes the valve
140
to assume its open condition. The space
128
above the soap
126
is then placed in communication with the atmosphere and the pressure in the space
128
increases to atmospheric pressure. The soap
126
can thereupon flow out of the reservoir
114
into the tubular member
144
and through the dispensing opening
142
onto the hand below the opening
142
.
Upon withdrawal of the hand from below the dispensing opening
142
, infrared radiation from the energy emitter
148
is no longer reflected to the energy detector
150
. The energy detector
150
stops sending signals to the discrimination unit
156
which, in turn, causes the valve
140
to return to its closed condition. When the valve
140
closes, the space
128
above the soap
126
is again cut off from the atmosphere and a vacuum redevelops in the space
128
. Since the vacuum must overcome the kinetic energy of the flowing soap
126
, the vacuum overshoots the value required to simply prevent the outflow of the soap
126
from the reservoir
114
when the soap
126
is stationary. As a result, once the soap
126
stops flowing, the relatively small volume of soap
126
present in the straight section
144
a
of the tubular member
144
is drawn into the curved section
144
c
of the tubular member
144
. Inasmuch as the curved section
144
c
defines a depression between the straight sections
144
a
,
144
b
of the tubular member
144
, the soap
126
drawn out of the straight section
144
a
and into the curved section
144
c
is unable to escape from the curved section
144
c
while the valve
140
remains closed. Consequently, dripping of the soap
126
from the dispensing opening
142
is prevented.
The energy emitter
148
and the energy detector
150
of the soap dispenser
110
make it possible for the soap
126
to be discharged without touching the dispenser
110
. Hence, the dispenser
110
is more sanitary than conventional soap dispensers. The removable cover
116
of the soap container
112
also allows easy access to the interior of the reservoir
114
so that the reservoir
114
can be easily cleaned.
Inasmuch as the soap dispenser
110
employs gravity to discharge the soap
126
from the dispenser
110
, the dispenser
110
is relatively efficient. The efficiency of the dispenser
110
is enhanced because the fluid directly controlled by the valve
140
is air rather than the relatively viscous soap
126
.
Since the valve
140
need only allow the passage of air therethrough, the valve
140
can be designed with a small flow aperture. This enables the valve
140
to be actuated with a relatively small amount of energy as the energy required to actuate a valve increases with increasing flow aperture size. Consequently, the energy supplied by a single small battery can suffice to operate the dispenser
110
for an extended period, e.g., 90 days. Moreover, the same valve can be used to dispense liquids with a wide range of viscosities.
Various modifications are possible within the meaning and range of equivalence of the appended claims. For example, the liquid dispensed could equivalently be, without limitation, a soap, a lotion, a beverage, a cleaner, a disinfectant, an adhesive, or a fabric treatment. Similarly, the container could consist of a deformable structure. Therefore, while the invention has been shown and described herein in what is believed to be the most practical and preferred embodiments, it is recognized that departures can be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent processes and products.
Claims
- 1. A liquid dispenser comprising:a container for a supply of liquid, said container being provided with at least one opening for discharging liquid from said container; means for detecting objects at a spacing from said container; means for controlling the passage of liquid through said one opening, said controlling means having a first condition in which liquid is free to pass through said one opening and a second condition in which the passage of liquid through said one opening is inhibited, and said controlling means being designed to assume said first condition in response to the detection of an object by said detecting means and to revert to said second condition in response to discontinued detection of the object; and a circuit board, at least part of said detecting means and at least part of said controlling means being mounted on said circuit board.
- 2. The dispenser of claim 1, wherein said detecting means comprises an energy emitter and an energy detector.
- 3. The dispenser of claim 1, wherein said controlling means comprises a tube which extends into and is provided with an aperture in said container, said controlling means further comprising valve means for connecting said aperture with and disconnecting said aperture from the atmosphere.
- 4. The dispenser of claim 1, where in said liquid is a liquid soap.
- 5. The dispenser of claim 1, further comprising means for inhibiting dripping of liquid from said container.
- 6. The dispenser of claim 5, wherein said inhibiting means comprises a generally S-shaped tubular member.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5405058 |
Kalis et al. |
Apr 1995 |
A |
5505340 |
McBride, Jr. |
Apr 1996 |
A |