U.S. patent number 3,556,146 [Application Number 04/806,946] was granted by the patent office on 1971-01-19 for liquid dispensing device automatically operated by proximity of a hand thereto.
This patent grant is currently assigned to N. V. Metaalwarenfabriek "Venlo". Invention is credited to Johannes Groen.
United States Patent |
3,556,146 |
Groen |
January 19, 1971 |
LIQUID DISPENSING DEVICE AUTOMATICALLY OPERATED BY PROXIMITY OF A
HAND THERETO
Abstract
A liquid dispensing device, in particular for hospitals and
clinics, whereby the supply of hot or cold water to a wash bowl or
the like may be controlled without touching any valves by hand. The
water supply is regulated by an electromagnetic valve controlled by
a proximity detector operating as a variable voltage divider. The
proximity detector is fed with a high frequency signal and delivers
an output voltage which may be influenced by putting the hand near
the proximity detector. Separate proximity detectors for
controlling the supply of hot and cold water, respectively, are
mounted on the outlet pipe of the wash bowl in such manner that
they may be actuated either separately or simultaneously, os that
hot, cold or tepid water may be supplied as desired.
Inventors: |
Groen; Johannes (Loenen Vecht,
NL) |
Assignee: |
N. V. Metaalwarenfabriek
"Venlo" (Venlo, NL)
|
Family
ID: |
27428657 |
Appl.
No.: |
04/806,946 |
Filed: |
March 13, 1969 |
Current U.S.
Class: |
137/606; 4/623;
137/801; 251/129.05 |
Current CPC
Class: |
H03K
17/955 (20130101); E03C 1/05 (20130101); G01F
23/265 (20130101); Y10T 137/9464 (20150401); Y10T
137/87684 (20150401) |
Current International
Class: |
E03C
1/05 (20060101); G01F 23/26 (20060101); G01F
23/22 (20060101); H03K 17/94 (20060101); H03K
17/955 (20060101); E03c 001/04 (); F16k
019/00 () |
Field of
Search: |
;4/166,ELEC. FLUSH/
;137/606,607,801 ;251/129 ;340/258,258C |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
60,971 |
|
Mar 1968 |
|
DL |
|
1,124,436 |
|
Feb 1962 |
|
DT |
|
Primary Examiner: Nilson; Robert G.
Claims
I claim:
1. A liquid dispensing device, comprising an outlet pipe, at least
one electromagnetic valve regulating the flow of a liquid through
said outlet pipe, a proximity detector operating as a variable
voltage divider, associated with said electromagnetic valve and
attached to said outlet pipe, a high frequency oscillator, means
connecting said high frequency oscillator with said proximity
detector, a control circuit adapted to receive an input voltage and
to actuate said electromagnetic valve in dependence on said input
voltage, and means for supplying the output voltage of said
proximity detector to said control circuit, the arrangement being
such that the output voltage of the proximity detector may be
influenced by putting the hand near the same.
2. A liquid dispensing device as claimed in claim 1, wherein said
proximity detector comprises two series connected condensers having
one electrode in common and each having one separate electrode, one
of the said separate electrodes being connected with said high
frequency oscillator and the other one with said control circuit,
the arrangement being such that the output voltage of said
proximity detector may be influenced by putting the hand near said
common electrode.
3. A liquid dispensing device as claimed in claim 1, wherein said
proximity detector comprises a dielectric plate, three juxtaposed
separate electrodes on one side of said plate, a continuous
electrode facing the said separate electrodes on the other side of
said plate, ground connections for said continuous electrode and
for the middle one of the said separate electrodes, and means
connecting one of the outer separate electrodes with said high
frequency oscillator and the other outer separate electrode with
said control circuit, the arrangement being such that the output
voltage of said proximity detector may be influenced by putting the
hand near the said separate electrodes.
4. A liquid dispensing device as claimed in claim 3, further
comprising an impedance transformer between said proximity detector
and said control circuit.
5. A liquid dispensing device, comprising an outlet pipe , two
electromagnetic valves regulating the flow of different liquids
through said outlet pipe, two proximity detectors operating as
variable voltage dividers, each associated with one of the said
electromagnetic valves attached to said outlet pipe, a common high
frequency oscillator, means connecting said high frequency
oscillator with each of the said proximity detectors, two control
circuits each associated with one of the said electromagnetic
valves and each adapted to receive an input voltage and to actuate
the associated electromagnetic valve in dependence on said input
voltage, and means for supplying the output voltage of each of the
said proximity detectors to the associated control circuit, the
arrangement being such that the output voltage of each of the said
proximity detectors may be influenced by putting the hand near the
same.
6. A liquid dispensing device as claimed in claim 5, wherein the
two electromagnetic valves regulate the flow of hot and cold water
through said outlet pipe, respectively.
7. A liquid dispensing device as claimed in claim 5, wherein the
two proximity detectors are arranged on opposite sides of said
outlet pipe.
8. A liquid dispensing device as claimed in claim 5, wherein the
two proximity detectors are arranged on said outlet pipe in such
positions that they may be simultaneously influenced by one
hand.
9. A liquid dispensing device as claimed in claim 5, further
comprising an insulating housing attached to said outlet pipe and
enclosing the two proximity detectors, and means within said
housing to screen the two proximity detectors with respect to each
other.
10. A liquid dispensing device as claimed in claim 5, further
comprising a group of connecting lines for each proximity detector,
means for insulating each of the said groups, and means for leading
the said insulated groups through said outlet pipe.
11. A liquid dispensing device, comprising an outlet pipe, at least
one electromagnetic valve regulating the flow of a liquid through
said outlet pipe, a proximity detector operating as a variable
voltage divider, associated with said electromagnetic valve and
attached to said outlet pipe, a high frequency oscillator, means
connecting said high frequency oscillator with said proximity
detector, means for amplifying the output voltage of said proximity
detector, rectifying means converting said amplified output voltage
into a direct voltage, and control means actuating said
electromagnetic valve in dependence on said direct voltage in such
manner that said valve is opened by a first proximity, and closed
again by a second proximity.
12. A liquid dispensing device as claimed in claim 11, wherein the
said control means comprises a first, a second and a third relay
each having at least one contact, said first relay being energized
at each proximity, an energizing circuit for said second relay
extending through a make contact of said first relay and a break
contact of said third relay, a circuit for holding said second
relay and for energizing said third relay extending through a break
contact of said first relay and a first make contact of said second
relay, a holding circuit for said third relay extending through a
make contact of said first relay and a make contact of said third
relay, and an energizing circuit for said electromagnetic valve
extending through a second make contact of said second relay.
13. A liquid dispensing device as claimed in claim 11, wherein the
said control means comprise a Schmitt trigger fired at each
proximity, a flip-flop changed over at each firing of said Schmitt
trigger and having a zero-output and a one-output and means for
energizing said electromagnetic valve connected with the one-output
of said flip-flop.
14. A liquid dispensing device as claimed in claim 12, further
comprising a DC source for feeding the said control means, and a
Zener diode inserted between said DC source and the said control
means.
15. A liquid dispensing device as claimed in claim 13, further
comprising an AC source, a thyristor having a gating electrodes,
means for connecting said electromagnetic valve with said AC source
through said thyristor, and means connecting the gating electrode
of said thyristor with the one-output of said flip-flop.
16. A liquid dispensing device as claimed in claim 13, further
comprising a resetting circuit for said flip-flop, a condenser in
said resetting circuit, charging means for said condenser, means
for deriving a voltage impulse from the said charging means, and
means for supplying said voltage impulse to said flip-flop in such
manner, that said flip-flop is kept in its zero-condition during a
predetermined interval following the time at which the liquid
dispensing device is switched on.
Description
BACKGROUND OF THE INVENTION
It is known to regulate the supply of water to a wash bowl by means
of a proximity detector inserted in the frequency determining
circuit of a high frequency oscillator. When a hand is brought into
the vicinity of the detector, the operation of the oscillator is
modified or even interrupted, whereby a signal is generated that
may be used to control an electromagnetic valve. This arrangement
has the limitation that a separate oscillator is required for each
valve to be controlled.
It is also known to regulate the supply of water to a wash bowl by
the interception of light impinging on a photo cell. With such an
arrangement, it may occur that the water supply is actuated at an
undesired time by an accidental interception of the light rays.
Furthermore, photoelectric devices of this kind are rather
susceptible to the flickerings generated by luminescent lamps upon
their ignition.
SUMMARY OF THE INVENTION
It is the main object of the invention to provide an improved
liquid dispensing device of the above-mentioned kind wherein the
limitations of the known devices have been overcome.
A further object of the invention is to provide a liquid dispensing
device of the above-mentioned kind wherein separate proximity
detectors for controlling the supply of hot and cold water to a
wash bowl may be actuated either separately or simultaneously, so
that hot, cold or tepid water may be supplied as desired.
Another object of the invention is to provide a liquid dispensing
device of the above-mentioned kind wherein several electromagnetic
valves may be controlled with the aid of a common high frequency
oscillator.
According to the invention, the outlet pipe carries at least one
proximity detector operating as a variable voltage divider, to
which a high frequency signal is supplied and of which the output
voltage may be influenced by putting the hand near the proximity
detector, the said output voltage being used to control an
associated electromagnetic valve.
Two different constructions for the proximity detector will be
disclosed hereinafter. In the first construction, the proximity
detector comprises two series connected condensers having one
electrode in common and each having one separate electrode. The
high frequency signal is supplied to one of the separate electrodes
and the output voltage is taken from the other separate electrode.
The output voltage may be influenced by putting the hand near the
common electrode.
In the second construction, the proximity detector comprises a
dielectric plate carrying on one of its sides three juxtaposed
electrodes of which the middle one is grounded. The high frequency
signal is supplied to one of the outer electrodes and the output
voltage is taken from the other outer electrode. The other side of
the plate carries a continuous grounded electrode facing the three
juxtaposed electrodes. The output voltage may be influenced by
putting the hand near the three juxtaposed electrodes.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows the circuit diagram of a device according to the
invention provided with two proximity detectors.
FIG. 2 shows a first embodiment of the receiver connected with each
of the two proximity detectors in FIG. 1.
FIG. 3 shows a sensing head mounted on the outlet pipe of a wash
bowl and comprising two proximity detectors, which may be used in
the device according to FIG. 1.
FIG. 4 shows a cross section of the sensing head according to the
line IV-IV in FIG. 3.
FIG. 5 shows a second embodiment of the receiver, in combination
with an alternative embodiment of the proximity detector.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, K1 and K2 denote two feed terminals to which a DC
voltage of 80 v. is supplied, the DC voltage being obtained by
rectification of AC voltage at the mains. By means of a voltage
divider comprising the series connection of a resistor R1 and a
Zener diode Z1, a DC voltage of 3.6 v. is obtained which is used to
feed an impulse generator IG.
The impulse generator IG produces a series of rectangular impulses
having a frequency of 50--200 kc, which is supplied through a
resistor R2 to the base of a transistor T1, of which the emitter is
grounded and the collector is connected through a resistor R3 to
the potential of 80 v. Furthermore, the collector of transistor T1
is grounded through a Zener diode Z2, having a Zener voltage of
about 40 v., so that rectangular impulses with a constant amplitude
of 40 v. may be taken from said collector. These impulses are
supplied to the sensing head OK through a coaxial cable L1.
The sensing head OK contains two proximity detectors turned away
from each other in such manner that they may be separately
influenced by hand. The first proximity detector comprises two
series connected condensers C1 and C2, each having a capacity of
0.5 pF, for instance, and having a common electrode E1. The second
proximity detector is carried out in exactly the same manner, and
comprises two series connected condensers C3 and C4 with a common
electrode E2. The common electrodes E1 and E2 lie on the outside of
the sensing head. If the hand is put near one of these electrodes,
a capacitive ground connection is formed, whereby the output
voltage is considerably reduced.
The output voltages of the two proximity detectors are each
supplied through an associated coaxial cable L2, or L3,
respectively, to an associated receiver 01, or 02,
respectively.
The arrangement may be such that the receiver 01 controls an
electromagnetic valve for the supply of hot water, and that the
receiver 02 controls an electromagnetic valve for the supply of
cold water. Thus, the supply of hot water may be initiated or
terminated by putting the hand near the first proximity detector,
and the supply of cold water may be initiated or terminated by
putting the hand near the second proximity detector. If desired,
the two valves may be opened simultaneously to obtain a supply of
tepid water.
The construction of the receivers 01 and 02 is shown in FIG. 2. The
output voltage of the associated proximity detector as taken from
cable L2 or L3 is supplied to the terminals K3 and K4. The terminal
K3 is connected with the base of a transistor T2 to which a
suitable bias voltage is supplied through a resistor R4. The
emitter of transistor T2 is grounded, and the collector is
connected with the feed line through a resistor R5. The collector
voltage of transistor T2 is supplied to the base of a transistor T3
operating as an emitter follower. The emitter of transistor T3 is
grounded through a resistor R6 and a condenser C6 in parallel with
each other, and connected with the base of a transistor T4 through
the series connection of a condenser C6 and an a adjustable
resistor R7. The network R6, C5 integrates the current impulses
produced by transistor T3, so that a DC voltage occurs across said
network. Variations of this DC voltage are transmitted to
transistor T4 through elements C6 and R7. The base of transistor T4
is connected with the feed line through a resistor R8 in order to
produce a suitable bias voltage. The emitter of transistor T4 is
grounded, and the collector is connected with the feed line through
a resistor R9. The collector voltage of transistor T4 is supplied
to the base of a transistor T5 of which the emitter is grounded
through a diode D1, and the collector circuit contains the series
connection of a resistor R10 and the energizing winding of a relay
RA; a condenser C7 is connected in parallel with this winding in
order to render the relay slow to deenergize. The relay RA has a
switch-over contact ra.
It is pointed out that the feed voltage for transistors T4 and T5,
amounting to about 20 v., is derived from the 80 v. voltage by
means of a voltage divider consisting of a resistor R11 and a Zener
diode
BRIEF DESCRIPTION OF THE DRAWINGS
Under normal circumstances the DC voltage at the base of transistor
T4 has such a value that this transistor is conductive. Transistor
T5 is cutoff in this case. However, if a hand is put near the
proximity detector, the AC voltage supplied to the receiver is
reduced to such an extent, that the DC voltage across network R6,
C5 vanishes, whereby a negative voltage impulse is transmitted to
transistor T4, so that the latter is cut off. Transistor T5 is now
rendered conductive, so that relay A is energized. Thus, relay RA
is energized at each proximity, i.e. every time when the hand is
put near the proximity detector.
When relay RA is energized for the first time and contact ra is
changed over, relay RB is energized through contacts ra and rc. A
diode D2 is connected in parallel with the energizing winding of
relay RB. Relay RB changes over its contacts rb1 and rb2, and the
magnet M of the electromagnetic valve is energized through contact
rb2, so that the valve is opened.
After a delay determined by a condenser C7, relay RA is
deenergized. Relay RB remains energized through contacts ra and
rb1. At the same time, relay RC is energized,; a diode D3 is
connected in parallel with the energizing winding of this relay.
Contact rc interrupts the energizing circuit of relay RB comprising
contact ra.
If the hand is again put near the proximity detector, so that relay
RA is energized anew, the holding circuit of relay RB is
interrupted, so that this relay is deenergized. Contact rb2
interrupts the circuit of magnet M, so that the liquid supply is
terminated. Relay RC remains energized through contacts ra and rc,
so that the direct energizing circuit of relay RB remains
interrupted. As soon as relay RA is deenergized, relay RC is also
deenergized, and the circuit returns to the initial condition.
The circuits of relays RB and RC comprise decoupling diodes D4, D5
and D6. Relays RB and RC are fed through a Zener diode Z5 having a
Zener voltage of 56 v., so that only a voltage of 24 v. is
available for these relays. The effect of this arrangement is that
relays RB and RC are deenergized and the valve is closed when the
feed voltage drops below a predetermined value; in this case, the
actuation by means of the proximity detectors is rendered
impossible, so that the valve cannot be closed by these detectors
any more.
Diode D7 serves to discharge condenser C6 when the feed voltage
disappears; otherwise an impulse operating the valve might occur
when the feed voltage returns.
The transistors are operated as switches, so that they are either
cut off or saturated; the sensitivity to outside interference is
reduced to a minimum in this manner.
In FIG. 3, the outlet pipe of a wash bowl is indicated at 1. The
water leaves the outlet pipe through an outlet opening 2. A
rectangular recess has been provided in the body of the outlet pipe
at the upper left of FIG. 3, so as to obtain a platform carrying
the sensing head. The sensing head is provided with a housing 3
made of a synthetic material and closed at the side turned towards
the outlet pipe by means of a metal lid 4 attached to the housing
by means of an adhesive. The lid 4 is provided with two conical
projections 5 fitting into corresponding recesses of the outlet
pipe and adapted to receive screws (not shown) with a countersunk
head, by means of which the sensing head is secured to the outlet
pipe. These screws are accessible through bores in two block-shaped
bodies 6 and 7 placed on the bottom of the housing. After the
screws have been fastened, these bores are filled up with casting
resin or a similar hardening mass.
As appears from FIG. 4, which shows a cross section of the sensing
head according to line IV-IV in FIG. 3, the proximity detectors 8
and 9 are arranged between the bodies 6 and 7 and the side walls of
the housing. The detectors are screened with respect to each other
by means of a plate 10.
The lid 4 is provided with an opening 11 (FIG. 3) for passing the
connecting lines for the detectors 8 and 9. These lines are led, as
indicated at 12, through the inside of the outlet pipe in an
insulated fashion.
Each of the detectors 8 and 9 comprises two condenser electrodes 13
and 14, separated by a dielectric plate 15 from a common electrode,
which is situated near the side wall of the housing, so that it may
readily be influenced from the outside.
When the hand is put in front of the sensing head, the two
detectors are influenced simultaneously, so that the
electromagnetic valves are actuated at the same time; in this
manner, a supply of tepid water may be obtained.
Preferably, the housing 3 is filled up, after the electric
components have been mounted, with a casting resin or a similar
hardening mass. The lid 4 may be left out, as desired; in this
case, the sensing head is secured to the outlet pipe by means of
longer screws extending through the bores of bodies 6 and 7.
Lines L1, L2 and L3 (FIG. 1) may be combined into a coaxial cable
with three inner conductors.
Referring to FIG. 5, each of the proximity detectors comprises a
plate 16 made of a dielectric materials, and carrying three
juxtaposed electrodes 17, 18 and 19 on one side, and a continuous
electrode 20 on the other side. The electrodes 18 and 20 are
grounded. A common impulse generator IG, which may be followed by
an amplifier in the manner as shown in FIG. 1, supplies a high
frequency signal to each of the electrodes 17. The output voltage
of each proximity detector is taken from the electrode 19, and
supplied to an associated control circuit; only one of these
control circuits is shown in the drawing. Since the capacity
between the electrodes 17 and 19 is small, and a relatively low
frequency is used, the proximity detectors have a very high output
impedance. For this reason, the output voltage taken from the
electrode 19 is first supplied to an impedance transformer 21,
which may comprise the combination of a field-effect transistor and
an ordinary transistor; in practice, such a combination may have,
for instance, an input impedance of 100 megohms, and an output
impedance of 199 ohms.
The output voltage of impedance transformer 21 is supplied through
an amplifier 22 to a rectifier 23 converting the high frequency
impulses into a direct voltage. It is advisable to use a voltage
doubling rectifier, for instance of the Greinacher type, and to
select the polarity in such manner that a negative direct voltage
is obtained. This direct voltage is supplied through an emitter
follower 24 to a Schmitt-trigger 25. Thus, whenever the hand is
brought into the vicinity of the proximity detector, so that the
output voltage of the same is considerably reduced, a positive
impulse is supplied to the Schmitt trigger, whereby the latter is
changed over and delivers an output impulse to a flip-flop 26.
Thus, the flip-flop 26 is changed over from the zero-condition to
the one-condition by a first proximity, returned to the
zero-condition by a second proximity, and so on. The output voltage
delivers by the flip-flop in its one-condition is used to energize
the associated electromagnetic valve.
For this purpose, the said output voltage is supplied to the gate
electrode of a thyristor 27, connected with an AC source in series
with the electromagnetic valve 28. As long as the flip-flop 26 is
in its one-condition, the thyristor is fired during each cycle of
the AC voltage, so that the valve is energized. When the flip-flop
returns to its zero-condition, the valve is put out of action. If
desired, the thyristor may be fed with a pulsating voltage taken
from a rectifier bridge, so that the thyristor is fired during each
half cycle.
When the device is switched on, care must be taken that the
flip-flop 26 is brought into its zero-condition, since otherwise
the liquid supply would start immediately. For this purpose, a
resetting circuit 29 has been provided, which supplies a long
voltage impulse to the flip-flop 26, whereby the latter is brought
into and/or kept in its zero-condition. The said voltage impulse is
taken from the charging circuit of a condenser, so that it vanishes
as soon as the condenser has been fully charged.
* * * * *