U.S. patent number 3,732,556 [Application Number 05/156,670] was granted by the patent office on 1973-05-08 for swimming pool alarm system.
Invention is credited to Nelson P. Caprillo, JOhn P. Husko, David Snyder.
United States Patent |
3,732,556 |
Caprillo , et al. |
May 8, 1973 |
SWIMMING POOL ALARM SYSTEM
Abstract
A swimming pool alarm system for instantly providing an audible
or other alarm in response to a person or other object falling into
the water. According to the invention, the alarm is adapted to be
energized and held in the energized state by electronic switching
means that switches from its "off" to its "on" condition in
response to a trigger pulse from normally open sensor conductor
means which is closable by a momentary splash of water thereon.
Such sensor conductor means substantially completely circumscribes
the pool closely spaced above the normal water level thereof,
whereby the splash or wave motion from an object falling into the
pool any place about the periphery thereof will momentarily close
the sensor conductor means and thereby turn the switching circuit
means "on" to actuate the alarm.
Inventors: |
Caprillo; Nelson P. (Arleta,
CA), Snyder; David (Canoga Park, CA), Husko; JOhn P.
(Tarzana, CA) |
Family
ID: |
22560536 |
Appl.
No.: |
05/156,670 |
Filed: |
June 25, 1971 |
Current U.S.
Class: |
340/566; 73/304R;
200/61.04; 340/620 |
Current CPC
Class: |
G08B
21/082 (20130101) |
Current International
Class: |
G08B
21/00 (20060101); G08B 21/08 (20060101); G08b
013/16 () |
Field of
Search: |
;340/261,244R,244C,258R
;200/190 ;73/34R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Trafton; David L.
Claims
We claim:
1. A swimming pool alarm system which comprises normally
unenergized alarm means, electric circuit means operatively
connected to said alarm means and adapted to energize said alarm
means in response to a sensed signal, and sensor means electrically
connected to said circuit means, at least a portion of said sensor
means extending around substantially the entire perimeter of a
swimming pool closely spaced above the normal water level thereof,
said sensor means being operative to provide a sensed signal to
said circuit means to energize said alarm means in response to the
contacting of said portion of said sensor means by disturbed water
of the pool at any point around the perimeter of the pool.
2. A swimming pool alarm system as defined in claim 1, wherein said
circuit means comprises electronic switching means that is switched
by said sensed signal from said sensor means from a normal
generally non-conducting "off" condition to a conducting "on"
condition.
3. A swimming pool alarm system as defined in claim 2, wherein said
electronic switching means include SCR circuit component means.
4. A swimming pool alarm system as defined in claim 1, which
includes a manually operable electrical switch in said circuit
means that is selectively movable between an open position wherein
said circuit means is disarmed and unresponsive to said sensor
means, and a closed position wherein said circuit means is armed
and responsive to said sensor means.
5. A swimming pool alarm system as defined in claim 4, wherein said
circuit means comprises electronic switching means which, in said
closed position of said manually operable switch, is normally in a
generally non-conducting "off" condition but is adapted to be
switched by said sensed signal from said sensor means to a
conducting "on" condition in which it remains until said manually
operable switch is moved to its said open position.
6. A swimming pool alarm system as defined in claim 1, wherein said
sensor means comprises normally open electrical conductor means
closable by contact therewith of disturbed water of the pool.
7. A swimming pool alarm system as defined in claim 1, wherein said
alarm means comprises at least one audible alarm device.
8. A swimming pool alarm system as defined in claim 7, wherein said
audible alarm device is located adjacent to the swimming pool.
9. A swimming pool alarm system as defined in claim 7, wherein said
audible alarm device is located remote from the swimming pool.
10. A swimming pool alarm system which comprises normally
unenergized alarm means, electric circuit means operatively
connected to said alarm means and adapted to energize said alarm
means in response to a sensed signal, and sensor means electrically
connected to said circuit means, at least a portion of said sensor
means extending around substantially the entire perimeter of a
swimming pool closely spaced above the normal water level thereof,
said sensor means being operative to provide a sensed signal to
said circuit means to energize said alarm means in response to the
contacting of said portion of said sensor means by disturbed water
of the pool at any point around the perimeter of the pool, said
sensor means comprising normally open electrical conductor means
closable by contact therewith of disturbed water of the pool, and
said sensor conductor means comprising a pair of generally
parallel, generally uniformly spaced conductors extending around
substantially the entire perimeter of a swimming pool spaced above
the normal water level of the pool.
11. A swimming pool alarm system as defined in claim 10, wherein
the lowermost of said pair of sensor conductors is spaced in the
range of from about one inch to about three inches above the normal
water level of the pool.
12. A swimming pool alarm system which comprises normally
unenergized alarm means, electric circuit means operatively
connected to said alarm means and adapted to energize said alarm
means in response to a sensed signal, and sensor means electrically
connected to said circuit means, at least a portion of said sensor
means extending around substantially the entire perimeter of a
swimming pool closely spaced above the normal water level thereof,
said sensor means being operative to provide a sensed signal to
said circuit means to energize said alarm means in response to the
contacting of said portion of said sensor means by disturbed water
of the pool at any point around the perimeter of the pool, said
sensor means comprising normally open electrical conductor means
closable by contact therewith of disturbed water of the pool, and
said sensor conductor means comprising a first electrical conductor
extending around substantially the entire perimeter of a swimming
pool spaced above the normal water level of the pool, and a second
electrical conductor extending into the pool with a portion thereof
normally submerged below the normal water level of the pool.
13. A swimming pool alarm system as defined in claim 12, wherein
said first electrical conductor is spaced in the range of from
about one inch to about three inches above the normal water level
of the pool.
14. A swimming pool alarm system which comprises normally
unenergized alarm means, electric circuit means operatively
connected to said alarm means and adapted to energize said alarm
means in response to a sensed signal, and sensor means electrically
connected to said circuit means, at least a portion of said sensor
means extending around substantially the entire perimeter of a
swimming pool closely spaced above the normal water level thereof,
said sensor means being operative to provide a sensed signal to
said circuit means to energize said alarm means in response to the
contacting of said portion of said sensor means by disturbed water
of the pool at any point around the perimeter of the pool, said
sensor means comprising normally open electrical conductor means
closable by contact therewith of disturbed water of the pool, and
said conductor means at least in part comprising lead foil tape
adhesively bonded to the side of a swimming pool.
Description
BACKGROUND OF THE INVENTION
Most swimming pool safety measures are in the nature of physical
barriers such as fences, gates and the like, and sometimes pool
covers. Such conventional protective measures are very expensive,
yet they do not provide positive assurance against accidental
drownings resulting from a child or other non-swimmer falling into
the water from the side of the pool or from some apparatus
associated with the pool such as a diving board, slide or the like.
In fact, fences and gates often serve as an attractive nuisance for
children to climb over. Additionally, such conventional physical
barriers are generally troublesome to operate, with the result that
gates are frequently left unlocked, and pool covers are often left
in the open position when the pool is unattended.
Another problem in connection with such conventional physical
barrier type swimming pool safety measures is that in the event
they for some reason fail to stop a child or other non-swimmer from
accidentally falling into the water, they do not provide any
warning of the occurrence; in fact, such physical barriers provide
an obstruction to visual observation of the pool and dampen sounds
emanating from the pool so as to compound such an accident once it
has occurred.
A still further problem in connection with such physical barrier
safety measures applied to swimming pools is that while they may be
regularly closed and locked when the pool is unattended for a
substantial period of time, as for example overnight or while the
proprietor is away for the weekend, nevertheless such barriers are
generally left open and unlocked for extended periods of time
during the day or evening when people may be using the pool for
only part of the time, and perhaps going into and out of an
adjacent house or other structure for meals, to use lavatory
facilities, or the like. Several minutes of such non-attendance of
the pool provide sufficient time for an accidental drowning to
occur.
SUMMARY OF THE INVENTION
In view of these and other problems in the art, it is a general
object of the present invention to provide a novel swimming pool
alarm system usable either alone or to supplement existing swimming
pool safety measures of the physical barrier type that will
instantly and reliably provide an audible or other alarm in
response to a person or other object falling into the water of the
swimming pool.
Another object of the invention is to provide a swimming pool alarm
system of the character described, wherein one or more alarm
devices are adapted to be energized and held in the energized state
by electronic switching means that switches from an armed but
non-conducting or "off" state to a conducting or "on" state in
response to a trigger pulse from normally open sensor conductor
means which is closable by a momentary splash of water thereon.
Another object of the invention is to provide a swimming pool alarm
system of the character described wherein the sensor that provides
the gating pulse to the electronic switching means for keying on
the alarm comprises conductor means disposed along the wall of the
pool closely spaced above the normal water level and substantially
completely circumscribing the pool, such conductor means providing
a normally open electrical circuit to said switching means that is
adapted to be momentarily closed or shorted by disturbed water of
the swimming pool splashing or surging thereagainst to provide a
trigger pulse to said switching means for turning on the alarm.
Provision of said sensor conductor means around substantially the
entire perimeter of the pool and closely spaced above the normal
water level thereof assures that the splash or wave motion from the
object falling into the pool at any location about the periphery
thereof will actuate the alarm system. According to one form of the
invention, a pair of spaced, generally parallel sensor conductors
extend around the periphery of the pool, being adhesively bonded or
otherwise attached to the tile or other wall material of the pool
just above the normal water level, so that a disturbance of the
water adjacent the side of the pool at any point around the
periphery will cause the water as a conducting medium to bridge the
parallel sensor conductors to close the circuit and energize the
alarm. According to another form of the invention, only a single
sensor conductor extends peripherally about the wall of the pool
closely spaced above the normal water level, while the second
conductor is simply exposed to the water in the pool at any desired
point below the surface thereof.
The electronic switching circuit employed in the swimming pool
alarm system of the present invention can be armed to make the
system operative during periods of disuse of the pool, or disarmed
to make the system inoperative during periods of use of the pool,
by simply manipulating an electrical switch. The system preferably
utilizes a relatively low voltage battery as its source of
electrical energy to avoid any danger of shocks and so that the
system will not be vulnerable to commercial power failures. A
presently preferred semiconductor switching circuit according to
the invention draws so little current in its armed but "off" or
non-conducting condition that a conventional 6 volt type "F"
lantern battery will last for many months under ordinary use of the
system, so that the battery can generally be replaced
seasonally.
Further objects and advantages of the present invention will appear
during the course of the following part of the specification,
wherein the details of construction and mode of operation of a
presently preferred embodiment are described with reference to the
accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view illustrating one form of
the present invention operatively associated with a swimming
pool.
FIG. 2 is an enlarged fragmentary elevational view of the alarm
system shown in FIG. 1.
FIG. 3 is a fragmentary elevational view similar to FIG. 2 but
illustrating another form of the invention.
FIG. 4 is a wiring diagram illustrating a presently preferred
circuit arrangement employed with the present invention.
DETAILED DESCRIPTION
Referring to the drawing, and at first particularly to FIGS. 1 and
2 thereof, one form of the invention is illustrated in these
figures operatively disposed in combination with a swimming pool
generally designated 10. The swimming pool 10 includes a generally
vertical peripheral wall 12 which may be rectangular or otherwise
configured in horizontal section, and within which the water of the
pool is confined. According to conventional construction the pool
is surrounded by a deck 14, the deck 14 that is illustrated in the
drawing being of a modern cantilever type having an edge 16 which
projects somewhat over the wall 12. A diving board 18 is shown
mounted on the deck 14, and it is to be understood that other
conventional apparatus (not shown) such as a slide, stairs for
entering and leaving the water, or the like may be associated with
the swimming pool 10 without interfering with the installation or
operation of the present invention.
The body of water contained in the swimming pool 10 is generally
designated 20, and its normal water level around the wall 12 is
designated 22.
The swimming pool alarm system shown in FIGS. 1 and 2 is generally
designated 24, and this includes sensor means 26 supported on the
wall 12 above the normal water level 22 and substantially
completely circumscribing the pool so as to be sensitive to a surge
or splash of water at any point around the entire periphery of the
pool. In the form of the invention shown in FIGS. 1 and 2, this
sensor means 26 includes a pair of elongated, parallel electrical
conductors 28 and 30 that are bonded to the wall 12 of the pool,
the conductors 28 and 30 being electrically connected through
respective connections 32 and 34 to an alarm unit 36. The parallel
conductors 28 and 30 are preferably substantially uniformly spaced
throughout their extent about the pool, and in the form shown in
FIGS. 1 and 2 they extend from their respective connections 32 and
34 around to free ends that are located just short of the
connection 32, such free ends being disposed close enough to the
connection ends that any splash or surge of the body 20 of water in
this region will bridge the parallel conductors 28 and 30 either
proximate the connections 32 and 34 or proximate the free ends of
the parallel conductors.
Alternatively, if desired, the free end of the lower conductor 28
may be joined to the connected end of conductor 28 so as to form a
closed loop of the conductor 28; while the free end of the upper
conductor 30 may extend either over or under the connection 32 in
electrically insulated relationship thereto and be connected to the
connected end of the conductor 30 so as to form a closed loop of
the conductor 30 (such closed loop construction not being
shown).
Although the present invention is not limited to any particular
dimensions for the spacing of the sensor conductors 28 and 30, in
an experimental example of the present invention reliable and
sensitive pulsing of the alarm unit 36 has been achieved with the
lower conductor 28 spaced approximately 11/2 inches above the
normal water level 22 of the pool, and the upper conductor 30
spaced approximately one-half inch above the lower conductor 28.
The presently preferred range of the spacing of the lower conductor
28 above the normal water level 22 is between about 1 inch and 3
inches. If such spacing is less than about 1 inch, the system tends
to become too sensitive to small disturbances in the body 20 of
water in the pool; while if the spacing of the lower conductor 28
above the water level 22 is more than about 3 inches, the
sensitivity of the alarm system tends to fall below a desired
minimum sensitivity for positively assuring energization of the
alarm in response to an object falling into the pool.
The conductors 28 and 30 may be made of any electrically conducting
material that is generally resistant to the corrosive effects of
the swimming pool water; i.e., any material that will remain
generally surface conducting so that in the operative state of the
alarm system a splash of water covering the two conductors 28 and
30 at any point around the pool will provide an electrical short or
connection between the conductors 28 and 30. One satisfactory type
of material for the conductors 28 and 30 is lead foil tape, between
about one-fourth inch and one-half inch in width. A satisfactory
form of such lead foil tape is No. 420 "Scotch" brand tape
manufactured by 3M Company of Saint Paul, Minnesota, which has a
water-resistant, pressure-sensitive adhesive on one side thereof.
Such tape can simply be pressure-bonded to the tile or other
surface material of the swimming pool wall 12.
Another satisfactory material for the conductors 28 and 30 is
stainless steel wire, as for example No. 20AWG stainless, which can
be bonded to the wall 12 by any suitable water-resistant adhesive,
as for example by means of an epoxy or other water insoluble
cement.
If desired, one of the conductors 28 and 30 may be composed of lead
foil tape and the other of stainless steel wire. Similarly, either
or both of the conductors 28 and 30 may be composed of any other
suitable conductive material within the scope of the invention, and
may be secured to the wall 12 by any suitable bonding means.
Some conventional swimming pool wall materials such as tile or
fiberglass are good electrical insulators, and accordingly if the
wall 12 is of such insulation material, it is not necessary to
insulate the conductors 28 and 30 relative to the wall. However, if
the wall 12 were of an electrical conducting character, then a
layer of insulation material would be provided between the
conductors 28 and 30 and the wall 12 so that the conductors 28 and
30 would not be bridged by the wall itself, but only by a splash or
surge of water thereon.
The alarm unit 36 is preferably contained in a suitable housing
which is louvered or otherwise apertured to allow the alarm noise
to project therefrom. The unit 36 may be placed at any convenient
location outside of the wet area of the pool. FIG. 1 illustrates
the unit 36 disposed underneath the diving board 18, which is a
particularly convenient place therefor because it is close to the
sensor means 26 and also affords good protection for the alarm unit
36 and the connection leads 32 and 34.
Referring now particularly to FIG. 4 of the drawing, the presently
preferred circuit arrangement for energizing the alarm pursuant to
a splash or surge of water against the sensor conductors is an SCR
switching network arranged to conduct or switch "on" when the SCR
gate sees a positive potential. The circuit is energized by a
suitable dry cell battery 38, as for example a 6 volt type "F"
lantern battery. The circuit includes positive and negative
conductors 40 and 42, respectively, that are connected to the
battery 38, the positive conductor 40 having a switch 44 therein
that arms the circuit in its closed position and disarms the
circuit in its open position.
The SCR is designated 48, and includes an anode terminal 50, a
cathode terminal 52 and a gating terminal 54. The sensor conductor
connection 34 is electrically connected to the anode terminal 50 of
the SCR through a conductor 46; while the sensor conductor
connection 32 is electrically connected to the SCR gating terminal
54 through a resistor 56. The SCR cathode terminal 52 is connected
to the negative conductor 42.
A resistor 58, alarm bell 60, and a diode 62 are all connected in
parallel between the positive conductor 40 and the conductor 46.
The alarm bell 60 is preferably disposed within the alarm unit 36,
and if desired a second alarm bell 64 may also be connected between
the conductors 40 and 46, but may be positioned at a location that
is remote from the swimming pool, as for example in an adjacent
house.
Satisfactory values for the resistors 56 and 58 are 2.2 kilohms and
1.3 kilohms, respectively. A satisfactory SCR 48 is Radio Shack SCR
No. 276-1067, 6 amps, 200 volts. A satisfactory diode 62 is a 1N547
diode. Satisfactory bells 60 and 64 are Edwards Catalog No. 740
bells. Such particular values and designations for circuit
components are given by way of example only, and not of
limitation.
With the switch 44 in its open position as illustrated in FIG. 4,
the circuit is disarmed and completely inoperative so that the
swimming pool can be used without the alarm inadvertently being
actuated. All that is required to arm the circuit and thereby make
it responsive to an object falling into the water at any point
around the perimeter of the pool is to close the switch 44.
With switch 44 closed, positive voltage from the battery 38 is
provided through conductor 40 to one side of resistor 58, one side
of the coil in each of the alarm bells 60 and 64, and the cathode
of diode 62. In the normal armed but "off" condition of the
circuit, the bell coils do not have a completed circuit to the
negative conductor 42, or ground, through the SCR 48, so the bells
are unenergized. At this time, the positive voltage on conductor 40
is passed through resistor 58 to conductor 46 and thence through
connection 34 to the upper sensor conductor 30, so that the upper
sensor conductor 30 has this positive voltage thereon throughout
its length.
When water splashes or surges across the sensor conductors 28 and
30, positive voltage is instantly applied to sensor conductor 28
and thence through its connection 32 and resistor 56 to the gating
terminal 54 of SCR 48. At this point resistors 58 and 56 act as
current limiters for the gate circuit and protect the gate from an
over-current pulse.
When the gating terminal 54 of SCR 48 thus receives the positive
pulse as a result of the sensor conductors 28 and 30 being shorted
by the water, SCR 48 switches to its conducting or "on" state, and
the coils of the bells 60 and 64 now have a potential difference
thereacross, thus causing the bells to draw current and produce
their alarm sound. The diode 62 acts as an arc suppressant across
the bell coils and protects the SCR 48 from receiving impulses from
the rising and falling magnetic fields of the bell coils.
Once the SCR 48 is thus turned on by a splash or surge of water, it
remains in its "on" or conducting state, and the bells continue to
sound the alarm, as long as the switch 44 remains in its closed
position. Thus, to turn off the alarm it is necessary to manually
open the switch 44. Once switch 44 has been opened and the alarm
shut off, and the SCR 48 has accordingly been returned to its
non-conducting or "off" state, the switch 44 can then be closed
again so as to arm the circuit, and the alarm will not be sounded
again until another surge or splash of water closes the electrical
connection between the sensor conductors 28 and 30. Accordingly,
switch 44 serves both as an "on-off" switch as well as a reset
switch.
In the operation of test apparatus according to the invention
embodying the circuit arrangement illustrated in FIG. 4,
measurements indicate that the transient trigger time is in the
order of microseconds, the energization of the warning bell or
bells is in the order of milliseconds, and the sensitivity is such
as to require only on the order of about 0.3 volts from the sensor
means 26.
With the resistor 56 in the gate circuit, the SCR 48 is protected
against damage from a current reversal in the event that battery 38
should be connected the wrong way.
FIG. 3 illustrates a second form of the invention wherein the alarm
system is generally designated 24a. This system is the same as that
illustrated in FIGS. 1, 2 and 4, except for the sensor means 26a
which in this form of the invention includes only a single
peripheral conductor 66 that is disposed in closely spaced
relationship above the water level 22, preferably about 11/2 inches
above the water level 22, and preferably within the range of from
about 1 inch to about 3 inches above the water level 22. The single
peripheral conductor 66 is connected to the alarm unit 36 through a
connection 68. In this form of the invention, the other sensor
conductor is a conductor 70 that extends directly down into the
water 20. In the form illustrated in FIG. 3, the conductor 70
extends from the alarm unit 36 over the deck 14 and its edge 16 and
then generally vertically downwardly along the wall 12 so as to be
submerged in the water 20 below the normal water level 22 thereof.
If desired, this direct sensor conductor 70 may extend into the
water in the skimmer area of the pool, or the conductor 70 may
extend underground and come out through the wall 12 at any desired
underwater point.
Preferably, the connection 68 to the peripheral conductor 66 is
electrically connected to the conductor 46 in the circuit of FIG.
4, with the direct conductor 70 being connected to the gating
circuit, although such connections may be reversed if desired.
While the instant invention has been shown and described herein in
what are conceived to be the most practical and preferred
embodiments, it is recognized that departures may be made therefrom
within the scope of the invention, which is therefore not to be
limited to the details disclosed herein, but is to be accorded the
full scope of the appended claims.
* * * * *