Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to an aerosol dispenser.
It is }cnown to provide aerosol dispensers which permit
metered dispensing of an aerosol spray such as an
insecticide, air feshener, sanitizer etc. Thus when
dispensing an insecticide such dispensers can be used to
control flies, insects etc. by automatically, at pre-set
intervals, dispensing spray into the environment.
The object of the present invention is to provide an
aerosol dispenser which is of improved design and function
or at least provides the public with an alternative to
those hitherto known.
~roadly the invention consists of an aerosol dispenser
which comprises a housing within which an aerosol
container can be removably located, a dispensing nozzle
arrangement through which aerosol contained in the
container can be dispensed, valve means providing for
~communication between~ an outlet of the aerosol container
and the spray nozzle arrangement, and electronic control
means for activation of the valve means to facilitate a
metered dosage of aerosol to be dispensed from said spray
nozzle arrangement.~ Preferably said valve means is
solenoid~operated.
In~ the ~;following more detailed description of the
invention according to a preferred form~reference will be
made~to the accompanying~drawings in which:- ~
Figure l~is ~an exploded perspective view of the
dispenser, ~ ~ ~
Figure 2 is a cross-section view of the valve means
and
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Figure 3 is a block circuit diagram of the electronic
control means.
Referring to Figure 1 of the drawings the housing is
formed by a shaped cover 10 and a mounting plate 11 said
mounting plate including a drip tray 12. Apertures 13
are provided whereby the mounting plate can be attached to
a wall or any other suitable support surface.
An upper sloping wall surface of cover 10 includes a
nozzle opening 14 with an integral drip catcher. Thus an
aerosol container 15 can be located on drip tray 12 and
covered by cover 10.
The outlet 16 of aerosol container 15 has mounted thereon
a valve 18 with a one piece adapter collar 17 being
provided for this purpose. The outlet (shown generally at
20) of valve 18 thus communicates with nozzle opening 14
so that an aerosol spray from container 15 can be
dispensed via valve 18 through a nozzle communicating with
opening 14. Valve 18 is mounted to aerosol container 15
by end 19 (being of skirt form) snap engaging via adapter
collar 17~
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The front vertical wall of cover 10 includes a recess 24
in which a circuit board 21 is located and covered by
cover plate 22. A circuit board 25 is also located within
cover 10 and this includes an LED 23 which engages through
one of openings 23b in recess 24. The LED is visible
from external of cover 10 through one of windows 23a in
ccver plate 22. A photo transistor T is located in
alignment with another window 23a via an aligned opening
23b.
Power for the electronic control arrangement is derived
from a conventional battery or pack of batteries 26 which
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is coupled in a conventional manner to circuit board 25.
Valve means 18, which is solenoid operated, is also
coupled via leads to the circuit board 25.
As shown in Figure 2 the valve 18 comprises a body having
skirt 19 at a lower end thus when the valve 18 is located
on aerosol container 15 the outlet 16 of the container
locates within a recess 27. Recess 27 is in communication
with a passage 28. Located within passage 28 is a spring
29.
Located within the valve body is a solenoid indicated
generally at 30. A sleeve 31 is located between valve
member 32 and the solenoid coil, this sleeve 31 being
coaxial with chamber 27 and passage 28 and effectively
providing a guide within which valve member 32 can
slidingly move.
Figure 2 of the drawings shows to the left hand side of
the centre line valve 18 in its open position whereas to
the right hand side of the centre line the valve is shown
in its closed position. Thus a seating 33 is provided at
the outlet end of passage 28 such that when the valve is
in the open position the end of valve element 32 locates
on a plastic "C" washer 33a positioned on seat 33. In the
closed position, however, valve element 32 is lifted away
from:seat`33.
The opposite~ end of~valve element 32 includes a seating
pad 35 (preferab~ly made of a rubber material) which, when
the valve is in the closed:position locates against seat
Thus in the closed position of the:valve spring 29 forces
valve element 32 so that seating elément 35 engages on
seat 34~thus closlng a ~meterlnq ~orifice 38. Upon
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operation of the solenoid 30, however, valve element 32 is
drawn back against the bias of spring 29 such that the
lower end of valve element 32 seats via washer 33a on seat
33. This draws seating element 35 away from seat 34 thus
aerosol spray which has been prior dispensed from
container 15 via outlet 16, recess 27 and passage 28 to
fill the space within sleeve 31 (a clearance 36 beiny
provided between the radial projecting portions of valve
element 32) is permitted to flow out through metering
orifice 38 into dispensing chamber 39 and then through
mechanical break up nozzle 40 which is in communication
with opening 14 in cover 10.
The amount of aerosol dispensed is determined by the time
that the solenoid operated valve is open. Thus generally
the volume of spray within sleeve 31 is not fully
dispensed during the open period of the valve. When
valve member 32 returns to the closed position aerosol
spray from container 15 via its outlet 16 flows till there
is a pressure balance between the chamber defined between
~sleeve 31 and valve element 32 and the interior of
container 15.
Operation of valve 18 and the time during which the valve
is~ open i5 carried out electronically and to further
describe the invention reference will now be made to
Figure 3 of the drawings which illustrates a circuit
arrangement of a preferred form of the electronic control
means.
Circuit board 21 located in recess 24 incorporates a
pressure activated "on" switch 41 and an "off" switch 42.
The dlspenser is~thus activated by~pressing "on" switch 41
which causes capacitor 43 to commence charging and this in
turn causes the clock oscillator 45 to operate and allows
a clock divlder chip 46 to start dividing. The clock in a
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preferred form o~ the invention runs at 0.7 seconds and
the divider 46 establishes intervals ~or the output to the
spray solenoid 30 such intervals being adjustable by dip
switches associated with the select gate 47. Thus for
example the outputs from divider 46 can provide division
by 512, 1024 and 2048 to give six, twelve and twenty-four
minute outputs or by selecting combinations of such
divisions other output intervals. The output from the
select gate 47 thus operates solenoid on timer 48 which is
set at a constant time such as for example 0.022 seconds.
Line 49 from divider 46 is connected through a pulse
shortener 50 to an LED driver 51 which drives LED
indicator 23. The output 49 from divider ~6 provides
division by a number, such as for example four, which
controls flashing of LED 23 to indicate that the dispenser
is working correctly and that the battery condition is
good. There is, however, provided a low battery detector
52 which when detecting a battery condition of say 10~
causes, via pulse controller 50, the LED to have longer
flashes. Furthermore when the battery condition has
reached a critical point such as 5% the low battery
detector via the pulse controller 50 causes the LED to
give even longer flashes.
Thus as battery voltage decreases the LED on time
increases to a point where the user is aware that the
battery condition is near being unsuitable for continued
reliable operation of the solenoid valve. In the event
that the battery gets Iow when the dispenser is turned
off, the LED gives a "steady glow" until the battery is
completely dead.
When used as an insecticide spray there is no requirement
~or the dispenser to operate during hours of darkness thus
photo transistor T is coupled via a threshold detector 53
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which is in turn connected via a day switch 54 to the
select gate 47. Threshold detector 53 is also coupled to
an inverter 55 which is connected to the select gate 47
via a night switch 56.
Upon the threshold detector 53 detecting an output from
photo transistor T which is indicative of night time the
day switch 54 (which is closed to lock out the night
function) opens and night switch 56 is closed thereby
causing the dispenser to cease operation. However, when
photo transistor T once again goes lo this is detected by
the threshold detector 53 and the positions of switches 54
and 56 are reversed thereby automatically causing the
dispenser to recommence operation.
When operation of the dispenser is not required stop
switch 42 is activated which causes capacitor 43 to fully
discharge and thereby completely shut down operation of
the unit.
If manual operation is required switch 41 can be pressed
at any time during which the dispenser is operative and
via line 57 the solenoid on timer 48 will cause solenoid
30 to function as previously described.
All the operation times and divider ratios stated herein
are only by way of example and can be changed to suit the
product in the aerosol container and/or battery
requirements.
Circuitry according to the iLlustrated form is not only
effective in providing correct~and adjustable dispensing
intervals but also results in low power consumption
thereby enhancing battery life. The~provision of the LED
2~3 ensures~ that the user of the dispenser is aware that
the~dispenser is operating or is in a condition whereby
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some rectification steps need to be taken such as
replacement of the battery.
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