Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
This invention relates to a humidity control appliance
adapted for portable domestic and hospital use to add or remove
water vapour from air in the environment of the appliance
according to a selected humidity nurnber chosen by the operator
on a control dial of the appliance.
THE PRIOR ART
Prior types of humidity control appliances for domestic
use generally comprise a motor driven fan adapted to pass air
over an evaporator cloth rising from a water tank thus to add
moisture to the air in a room. Such devices have in the past
provided a humidity responsive switch device for disconnecting
the fan when the room humidity achieves a certain value. In
`~ addition, tin~ing circuits controlling the duration of the
addition of moistureto air have been employed. (:;enerally,
however, the discomfort of excessive moisture in a room environ-
ment usually arises when room heat is excessive. An air-
conditioning unit provides partial relief. Such air - conditioning
unit, however, operates responsive to temperature rather
than humidity though there will be a tendency for the humidity
to be reduced thereby.
OBJECTS ~F THE INVENTION
It is an object of the invention to provide a humidity control
appliance for domestic and hospital use adapted to ~ ontrol the
humidity of the air environment in a room responsive to the
~election of a humidity control number on a control dial
of the appliance by the operator.
It is another object of the invention to provide an appliance
as set forth herein which is adapted to increase or
decrease the hun~idity of environmental air in a room responsive
to adjustment of same by the operator.
DETAILED DESCRIPTION OF THE DRAWING
Other objects of the invention will be appreciated by
a study of the following specification taken into conjunction
with the accompanying drawing showing the preferred expression
of the invention and in which:
Figure 1 is a perspective view of a humidity control apparatus
according to the invention; and
Figure 2 is a diagrammatic illustration of the components of
the invention showing their relationships and the connections
therefor.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawing the humidity control appar-
atus 10 may be in a form of a general box shaped structure having
on the front panel 11 thereof an on-off switch 12 and a dial type
humidity control switch 13 preferably arranged above a louvered
panel 14 adapted to expel air in the direction the arrow 15. A
rear panel (not shown) has suitable openings for the entry of air.
; The interior of the appliance lO contains the components and the
e]ectric circuitry both diagrammatically illustrated in Figure 2.
With reference to Figure 2, humidity sensitive means
or humidistat 13a comprises a moisture swellable element or strip
16 formed of a material adapted to expand when subjected to
increasing moisture such as for example a strip of a "Mylar"type
of plastic material. The strip is attached at opoosite ends to
lever arms 17 and 18 and to springs 19 and 20 which maintain the
moisture sensitive element 16 under tension. Arms 17 and 18 are
pivotal about points 21 and 22.
The end of arm 18 opposite strip 16 is fastened to a
shorting bar 23, which moves into and out of contact with electrical
31 terminals 24 and 25. The end of arm 17 rides an eccentric cam
member 26 controlled as to its rotatable position by a shaft 27
which is manually rotatable by means of switch 1~. Clockwise rot-
ation of such shaft will cause the shorting bar 23 to advance in the
direction of arrow 28 toward the electrical terminals 24,25 whereas
rotation in the opposite direction will cause the shorting bar to
retreat from the terminals.
An increase in environmental humidity will result in
expansion of strip 16 with resulting clockwise movement of arm 18.
The shortin~ bar will move into contact with terminals 2~,25 thereby
activating the cooling operation described below. By contrast, a
decrease in humidity will result in movement of the shorting bar
away from terminals 24,25 with resulting deactivation of the cooling
operation.
Off-on switch 12 controls the electric c~rcuit of
motor 29 which drives fan 29a. In addition the switch controls
the electrical circuit which activates the refrigerating means.
The latter circuit electrically interconnects the power source, a
conventional motorized refrigerant compressor 30 and terminals 24,25
of the humidit~ control. Thus the compressor is electrically in
parallel through the shorting bar 23 with the fan motor 29.
Compressor 30 conventionally contains a reservoir
of refrigerant whereby refrigerant is pumped through high pres-
sure line 31 to a conventional condenser 31a. The condenser is
preferably located in the stream of air produced by the fan so
that the latent heat of the refrigerant is given up to the air.
The saturated liquid refrigerant which exits from the condenser
enters an expansion valve 32 in which its pressure is reduced
to a much lower value with simultaneous reduction in its temp-
erature. The lower tem~erature refrigerant is admitted into
the eva~orator 34 which is also located in the stream of air
31 operated by fan 29a~ The refrigerant leaving the evaporator
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passes through line 35 and enters the suction side of the
compressor.
Evaporator 34 is located directly above the
reservoir into which extends ~e~ mclns ~7 ln the form
of an evaporator cloth. The cloth may be any suitable open
weave c]oth. The upper portion 39 of the cloth may be sus-
pended in the stream of air generated by the fan by means of
frame 38.
It will be evident that when the cooling circuit
is energized, the refrigerating means described above serves
to chill the stream of air generated by the fan w;th result-
ing condensation of moisture from the surrounding atmosphere.
The moisture can be collected in tank 36.
Further it will be evident that when the circuit
is not energized, the fan 29acreates a stream of air which
follows path 15 and passes through the upper portion 39 of
the evaporator cloth 37. As it passes through the cloth,
moisture is added to the stream of air.
Thus for anys~ected setting of the humidity control
switch 13 the appliance of the invention will cause moisture to
be added to or extracted from the surrounding atmosphere accord-
22 ing to the humidity condition of the atmosphere.
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SUPPLEMENTARY DISCLOSIJRE
The operation of the humidity control apparatusof the invention may be controlled manually or may be fully
automatic. In the second sheet of drawings:
Figure 3 is a diagrammatic illustration of the components of
a manually operated device; and
Figure 4 ls a diagrammatic illustration of the components of
a fully automàtic device.
With reference first to Figure 3, the components of
the humidity control apparatus include a humidity control
apparatus or humidistat 45, compressor 47, condenser 49, expan-
sion valve 51 and an evaporator 53. Motor 55 activates a
fan 57. The compressor, condenser, expansion valve and evaporator
are in fluid-flow communication with each other and have the same
construction as the components illustrated in Figure 2. Fan 57
similarly has the same construction as fan29_ except that the
former fan is interposed between the condenser and evaporator
in order to suck air through the condenser 49 and to blow it
through the evaporator 53 and thereafter through evaporator
cloth 59 which is suspended above a liquid filled reservoir 61.
The construction of humidistat 45 is the same as
humidistat l3a in Figure 2 except that the former humidistat
is provided with a switch, generally 63, having a movable contact
63a which is movable from the illustrated position which completes
a first e]ectrical circuit 65 via power source 67, double pole
double throw switch 68 (when the handle 68a of the switch is
thrown to the left). Switch 63 is in the illustrated posi-tion
when the humidistat detects that the level of moisture in the
surrounding atmosphere is above a predetermined range and com-
pletion of the first circuit 65 causes activation of compressor 47
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and fan motor 55 with resulting cooling of the gas stream
generated by fan 57.
When the level of moisture is below a given
predetermined range, the movable contact 63a of the humidistat
45 will switch to the upper position therebv completing a
second electrical circuit 69 provided that the movable
contact 68a of switch 68 is closed to the right. CompLetion
of the second circuit causes activation of the fan motor 55
with resulting humidification of the stream of air produced
by fan 57.
The humidity control apparatus illustrated in
Figure 3 will only operate to humidify or dehumidify air in
the surrounding atmosphere provided that (a) the humidistat
detects either that the moisture`level in the air is above or below
a predetermined range and (b) that switch 68 completes which-
ever of the first or second circuits is required to restore the
humidity to the required range. For example, if the humidistat
detects that the humidity is too high, the apparatus will only
serve to restore the humidity to the required range provided
that switch 68 completes the first circuit 65. Similarly if
the humidity is too low, only where the switch 68 completes
the second circuit will the humidity control apparatus serve
to raise the humidity to within the required range.
The apparatus illustrated in Figure 4 is similar to
that illustrated in Figure 3 with the exception that a relay
generally 71 is substituted for switch 68 in Figure 3. Relay 71
serves to make the operation of the humidity control apparatus
28 fully automatic.
Switch 73 of humidistat 75 controls the electro-
magnets of relay 71. When the humiditv is within the required
range, switch 73 will be in the illustrated position in which
it contacts neither adjacent terminal. When the switch is
so positioned, the relay is deactivated and the movable
contact 77 of the relay is biased by a spring (not illustrated)
to the illustrated neutral position.
When the humidistat detects that the level of
moisture is above a predetermined range, contact 73 will move
upward to complete a first circuit 79 thereby drawing movable
contact 77 to the left and causing activation of the compres-
sor 81 and fan motor 83 with resulting condensation of the
moisture from the alr surrounding the apparatus.
By contrast, when the humidistat detects that the
moisture level is below a predetermined range, contact 73
will move downwardly to complete a second circuit 83 which
causes movable contact 77 of the relav to swing to the right
and thereby activate fan motor 83 with resulting humidifi-
cation of the surrounding air.
