U.S. patent number RE35,153 [Application Number 08/234,386] was granted by the patent office on 1996-02-06 for humidifier with float activated water level responsive turn off.
This patent grant is currently assigned to Duracraft Corporation. Invention is credited to Bernard Chiu.
United States Patent |
RE35,153 |
Chiu |
February 6, 1996 |
Humidifier with float activated water level responsive turn off
Abstract
A humidifier including a base defining a reservoir for retaining
a liquid volume having an upper surface; a humidification unit
removably mounted on the base and having an electrically energized
humidifier adapted to induce dispersion of liquid retained by the
reservoir, and a switch adapted in an active condition to energize
the humidifier and in an inactive condition to cause deenergization
thereof; and an actuator retained by the base and adapted for
movement between activating and inactivating positions with respect
to the switch, the actuator adapted in its activating positions to
actuate the switch into its active condition and in its
inactivating positions to actuate the switch into its inactive
condition and wherein both given changes in the level of the upper
surface and movement of the humidification unit relative to the
base produce the controlling movement of the .[.actuator.].
.Iadd.switch.Iaddend.. Mounting of a switch on a removable
humidification unit and an actuator for the switch in a base
supporting the unit facilitates desired shut-off in response to
either an inadequate water supply or removal of the unit.
Inventors: |
Chiu; Bernard (Ashland,
MA) |
Assignee: |
Duracraft Corporation
(Whitinsville, MA)
|
Family
ID: |
27056691 |
Appl.
No.: |
08/234,386 |
Filed: |
April 28, 1994 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
509885 |
Apr 17, 1990 |
5034162 |
|
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Reissue of: |
687141 |
Apr 18, 1991 |
05108663 |
Apr 28, 1992 |
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Current U.S.
Class: |
261/26;
261/107 |
Current CPC
Class: |
F24F
6/043 (20130101) |
Current International
Class: |
F24F
6/02 (20060101); F24F 6/04 (20060101); B01F
003/04 () |
Field of
Search: |
;261/26,107 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Sears Owners Manual for Kenmore.TM. Quiet Comfort.TM. Evaporative
Console Humidifier bearing notation "Printed in U.S.A. May 1990"
(see last page, lower right hand corner)..
|
Primary Examiner: Miles; Tim R.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent
application Ser. No. 07/509,885 filed Apr. 17, 1990, .Iadd.now U.S.
Pat. No. 5,034,162, .Iaddend.entitled High Capacity Portable
Humidifier.
Claims
What is claimed is:
1. A humidifier .Iadd.apparatus .Iaddend.comprising:
a base .[.means.]. defining a reservoir for retaining a liquid
volume having an upper surface;
a humidification unit removably mounted on said base .[.means.].
and comprising an electrically energized humidifier .[.means.].
adapted to induced dispersion of liquid retained by said reservoir,
a flow passage including a receiving end communicating with said
reservoir and a discharge end for discharging dispersed liquid
received therefrom, and .Iadd.a .Iaddend.switch .[.means.]. adapted
in an active condition to energize said humidifier .[.means.]. and
in an inactive condition to cause deenergization thereof;
.[.and.].
an actuator .[.means.]. retained by said base .[.means.]. and
adapted for movement between activating and inactivating positions
with respect to said switch .[.means.]., said actuator .[.means.].
adapted in said activating positions to actuate said switch
.[.means.]. into said active condition and in said inactivating
positions to actuate said switch .[.means.]. into said inactive
condition and wherein both given changes in the level of said upper
surface and movement of said humidification unit relative to said
base .[.means.]. produce said movement of said .[.actuator means.].
.Iadd.switch; and
a guide for guiding movement of said actuator between said
activating and inactivating positions.Iaddend..
2. A humidifier .Iadd.apparatus .Iaddend.according to claim 1
wherein said humidifier .[.means.]. comprises a blower .[.means.].
adapted to produce air flow through said passage between said
receiving end and said discharge end.
3. A humidifier .Iadd.apparatus .Iaddend.according to claim 2
including .Iadd.a .Iaddend.wick .[.means.]. having supply portions
disposed in said resorvoir below said upper surface and evaporation
portions disposed to intercept and transmit said air flow.
4. A humidifier .Iadd.apparatus .Iaddend.according to claim 3
wherein said wick .[.means.]. is adapted to provide by capillary
action a liquid flow from said supply portions to said evaporation
portions.
5. A humidifier .Iadd.apparatus .Iaddend.according to claim 4
wherein said actuator .[.means.]. comprises .Iadd.a .Iaddend.float
.[.means.]. having a buoyant lower end disposed in said reservoir
and adapted to be moved by changes in the level of said upper
surface, and an upper end adapted to engage and actuate said switch
.[.means.]., said float .[.means.]. being moved into its activating
position by levels of said upper surface above a predetermined
level and into its inactivating positions by levels of said upper
surface below said predetermined level. .[.6. A humidifier
according to claim 5 including guide means for guiding movement of
said float
means..]. 7. A humidifier .Iadd.apparatus .Iaddend.according to
claim .[.6.]. .Iadd.5 .Iaddend.wherein said switch .[.means.].
comprises an electrical switch operated into said active condition
by engagement with
said upper end of said float .[.means.].. 8. A humidifier
.[.apparatus.]. according to claim 2 wherein said actuator
.[.means.]. comprises .Iadd.a .Iaddend.float .[.means.]. having a
buoyant lower end disposed in said reservoir and adapted to be
moved by changes in the level of said upper surface, and an upper
end adapted to engage and actuate said switch .[.means.]., said
float .[.means.]. being moved into its activating position by
levels of said upper surface above a predetermined level and into
its inactivating positions by levels of said upper surface below
said predetermined level. .[.9. A humidifier according to claim 8
including
guide means for guiding movement of said float means..]. 10. A
humidifier .Iadd.apparatus .Iaddend.according to claim .[.9.].
.Iadd.8 .Iaddend.wherein said switch .[.means.]. comprises an
electrical switch operated into said active condition by engagement
with said upper end of
said float .[.means.].. 11. A humidifier .Iadd.apparatus
.Iaddend.according to claim 1 wherein said actuator .[.means.].
comprises .Iadd.a .Iaddend.float .[.means.]. having a buoyant lower
end disposed in said reservoir and adapted to be moved by changes
in the level of said upper surface, and an upper end adapted to
engage and actuate said switch .[.means.]., said float .[.means.].
being moved into its activating position by levels of said upper
surface above a predetermined level and into its inactivating
positions by levels of said upper surface below said predetermined
level. .[.12. A humidifier according to claim 11 including
guide means for guiding movement of said float means..]. 13. A
humidifier .Iadd.apparatus .Iaddend.according to claim .[.12.].
.Iadd.11 .Iaddend.wherein said switch .[.means.]. comprises an
electrical switch operated into said active condition by engagement
with said upper end of
said float .[.means.].. 14. A humidifier .Iadd.apparatus
.Iaddend.according to claim 1 including a liquid supply tank
removably mounted on said base .[.means.]. and juxtaposed with said
humidification unit, said supply tank adapted to provide controlled
liquid flow into said
reservoir. 15. A humidifier .Iadd.apparatus .Iaddend.according to
claim 14 wherein said humidifier .[.means.]. comprises a blower
.[.means.]. adapted to produce air flow through said passage
between said receiving end and
said discharge end. 16. A humidifier .Iadd.apparatus
.Iaddend.according to claim 15 including .Iadd.a .Iaddend.wick
.[.means.]. having supply portions disposed in said reservoir below
said upper surface and evaporation portions disposed to intercept
and transmit said air flow.
A humidifier .Iadd.apparatus .Iaddend.according to claim 16 wherein
said wick .[.means.]. is adapted to provide by capillary action a
liquid
flow from said supply portions to said evaporation portions. 18. A
humidifier .Iadd.apparatus .Iaddend.according to claim 17 wherein
said actuator .[.means.]., comprises .Iadd.a .Iaddend.float
.[.means.]. having a buoyant lower end disposed in said reservoir
and adapted to be moved by changes in the level of said upper
surface, and an upper end adapted to engage and actuate said switch
.[.means.]., said float .[.means.]. being moved into its activating
position by levels of said upper surface above a predetermined
level and into its inactivating positions by levels of said
upper surface below said predetermined level. .[.19. A humidifier
according to claim 18 including guide means for guiding movement of
said
float means..]. 20. A humidifier .Iadd.apparatus .Iaddend.according
to claim .[.19.]. .Iadd.18 .Iaddend.wherein said switch .[.means.].
comprises an electrical switch operated into said active condition
by engagement with said upper end of said float .[.means.]..
Description
BACKGROUND OF THE INVENTION
This invention relates generally to humidifiers and, more
particularly, to a humidifier with an improved liquid level
responsive shut-off.
Various types of humidifiers are used to increase the humidity in a
living environment. Such humidifiers use a variety of different
output mechanisms to disperse from a supply reservoir water which
has been preconditioned by, for example, atomization, evaporation
and vaporization. In the interest of energy conservation and
safety, many humidifiers are equipped with control systems that
deenergize an electrically energized output mechanism in response
to the exhaustion of the unit's water supply. Although providing a
desired shut-off function, prior liquid level responsive control
systems have exhibited various individual and collective
deficiencies such as high cost, irratic performance, and cumbersome
design configurations.
The object of this invention, therefore, is to provide a humidifier
with an improved control system for deenergizing an electrically
operated output mechanism in response to an absence of a sufficient
volume of water in a supply reservoir.
SUMMARY OF THE INVENTION
The invention is a humidifier including a base defining a reservoir
for retaining a liquid volume having an upper surface; a
humidification unit removably mounted on the base and having an
electrically energized humidifier adapted to induce dispersion of
liquid retained by the reservoir, and a switch adapted in an active
condition to energize the humidifier and in an inactive condition
to cause deenergization thereof; and an actuator retained by the
base and adapted for movement between activating and inactivating
positions with respect to the switch, the actuator adapted in its
activating positions to actuate the switch into its active
condition and in its inactivating positions to actuate the switch
into its inactive condition and wherein both given changes in the
level of the upper surface and movement of the humidification unit
relative to the base produce the controlling movement of the
actuator. Mounting of a switch on a removable humidification unit
and an actuator for the switch in a base supporting the unit
facilitates desired shut-off in response to either an inadequate
water supply or removal of the unit.
According to one feature of the invention, the actuator comprises a
float having a buoyant lower end disposed in the reservoir and
adapted to be moved by changes in the level of the upper surface,
and an upper end adapted to engage and actuate the switch, the
float being moved into its activating position by levels of the
upper surface above a predetermined level and into its inactivating
positions by levels below the predetermined level. This feature
provides the desired shut-off control with a highly functional
structural arrangement.
According to yet other features of the invention, the humidifier
includes a blower for producing air flow, wick means having supply
portions disposed in the reservoir below the upper surface and
evaporation portions disposed to intercept and transmit the air
flow. The shut-off system is particularly well suited for use with
an evaporative humidifier.
According to other features, the invention includes a guide for
guiding movement of the float, and the switch is an electrical
switch operated by engagement with the upper end of the float. The
guide insures proper movement of the float in response to changes
in the upper surface level.
According to still another feature, the invention includes a liquid
supply tank removably mounted on the base and juxtaposed with the
humidification unit. The conveniently located supply tank provides
controlled liquid flow into the reservoir thereby increasing
storage capacity.
DESCRIPTION OF THE DRAWINGS
These and other objects and features of the invention will become
more apparent upon a perusal of the following description taken in
conjunction with the accompanying drawings wherein:
FIG. 1 is a front perspective view of a portable humidifier
according to the invention;
FIG. 2 is a rear elevational view of the humidifier shown in FIG.
1;
FIG. 3 is a rear perspective view of a base unit of the humidifier
shown in FIG. 1;
FIG. 4 is a cross-sectional view taken along lines 4--4 of FIG. 1;
and
FIG. 5 is a schematic circuit diagram of a control circuit used in
the humidifier shown in FIGS. 1-4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A humidifier unit 11 includes a water storage tank 12 and an
evaporator housing 13 supported in juxtaposition on a base 14. As
shown most clearly in FIG. 3, the base 14 includes a bottom wall 15
and side walls 16-19 that together define a reservoir 21.
Projecting inwardly from each of the base side walls 16-18 in a
region below the evaporator housing 13 is a rectangularly shaped,
horizontally oriented bracket 22. Each of the brackets 22 retains a
wick element 23 having a framework 24 forming a plurality of
compartments each filled with a suitable absorbant capillary wick
material 25. A lower supply portion 26 of each wick element 23 is
positioned below its horizontal retaining bracket 22 within the
reservoir 21 while an upper evaporation portion 27 thereof is
disposed above its bracket 22 and above the reservoir 21.
Projecting upwardly from the bottom of the base 14 is a stem 28,
the purpose of which is described hereinafter.
The evaporator housing 13 is formed by side walls 31-34 and a top
wall 35 and has an open bottom end 36 opening into the reservoir
21. Supporting the bottom end 36 of the housing 13 is an internal
shoulder 37 on the base 14. The housing side walls 31-33 are
aligned with and directly above, respectively, the base side walls
16-18. Formed in lower portions of each of the housing side walls
31-33 are a plurality of inlet opening slots 38 while a plurality
of discharge opening slots 39 are formed in the top wall 35. The
interior of the evaporator housing 13 forms parallel air flow paths
extending between the inlet slots 38 in each of the housing side
walls 31-33 and the discharge slots 39 in the top wall 35.
Supported by the top wall 35 and extending into the evaporator
housing 13 is a blower assembly 41 that is controlled by an on-off
switch 42.
As illustrated in FIG. 4 the humidifier 11 is provided with liquid
level responsive shut-off system 51. Included in the system 51 is
an elongated, buoyant actuator float element 52 and an electrical
switch 53 actuated thereby, and a control circuit 54. The switch 53
and control circuit 54 are enclosed in a housing 56 supported by
the sidewall 34 of the evaporator housing 13. Connecting the
electrical switch 53 to the control circuit 54 are electrical leads
57, 58. The control circuit 54 is connected also to the motor 41
and the on-off switch 42 by an electrical cable 59. Preferably, the
switch 53 is of a conventional type that is internally biased into
an inactive open condition but can be moved into an active closed
position by an activator lever arm 60. Retaining a buoyant lower
end 61 of the actuator element 52 is a receptacle 62 extending
upwardly from the bottom wall 15 of the base 14. The opposite upper
end 64 of the actuator element 52 extends through an opening 65 in
a bottom wall 66 of the housing
In response to changes in the level of an upper surface 67 of a
liquid volume 68 in the reservoir 21, the buoyant actuator 52 moves
either upwardly or downwardly in a path guided by a guide bracket
69 supported by the sidewall 34 of the evaporator housing 13. With
the upper surface 67 of the liquid volume 68 at a predetermined
level L or above, the upper end 64 of the actuator element 52 is
moved into an activating position engaging the lever arm 60 and
moving the switch 53 into its active closed condition. However, at
levels of the upper surface 67 less than the predetermined level L,
the actuator element 52 floats downwardly to move the upper end 64
into an inactivating position that eliminates forcible engagement
with the lever arm 60. The switch 53 is thereby induced into its
inactive open condition. Also, regardless of the level of the upper
surface 67 of the liquid volume 68, relative separating movement
between the upper end 64 of the actuating element 52 and 40 the
switch 53 resulting from removal of the evaporation housing 13 from
the base 14 will cause the switch 53 to assume its inactive open
condition.
As shown in FIG. 4, the control circuit 54 includes a plurality of
interconnected transistors Q1-Q4 that receive DC power from a full
wave rectifier bridge 91. Supplying the rectifier bridge 91 is the
secondary of a transformer 93 having a primary connected to an AC
supply 94. Resistors R1-R3 and a first filter delay circuit C1, R4
are connected to the base of the transistor 50 Q1. Coupling the
transistors Q1 and Q2 are resistors R5 and R6. A resistor R8 and a
second filter delay circuit C2, R7 are connected to the base of the
transistor Q3, the emitter of which is connected to the base of the
transistor Q4. Connected between the transistors Q3, 55 Q4 and the
DC supply is a parallel combination of a resistor R9 and a winding
of a relay 99. Contacts 98 of the relay 99 and the manually
operated on-off switch 42 connect the motor 41 of the fan blower 40
to the AC supply 94.
OPERATION
To prepare the humidifier 11 for use, the tank 12 is removed from
the base 14 and the reservoir 21 is filled with water. In addition,
the tank 12 is filled and then inverted and positioned on the base
14. Water from the tank 12 flows through a control valve (not
shown) into the reservoir 21. As long as a supply of water exists
in the tank 12, the upper surface 67 of the water volume 68 is
retained at a desired level. Operation of the supply tank 12 is
conventional and a disclosure thereof appears, for example, in U.S.
patent application No. 07/509,885, now U.S. Pat. No. 5,034,162.
Prior to initiating operation of the humidifier unit 11, one of the
wick elements 23 is appropriately positioned within each of the
brackets 22 on the base 14 after removal of the housing 13. As
shown in FIG. 3, with the wick element 23 properly positioned, its
supply portion 26 includes an outer surface disposed directly
adjacent and parallel to the base side wall 16. Also an outer
surface of the evaporator portion 27 of the wick element 23 is
disposed directly adjacent and parallel to the inlet slots 38
formed in the housing side wall 31. Although for reasons of
clarity, only a single wick element 23 is shown in FIG. 3, it will
be understood that an identical wick element will be similarly
positioned in each of the brackets 22. Consequently, the supply
portion of each wick element 23 will be below the upper surface 67
of the water volume 68 in the reservoir 21 while the evaporator
portion 27 of each element 23 will lie above that level and
directly in an air flow path between one set of the inlet slots 38
and the discharge slots 39.
Energization of the fan 10 is established by closing the on-off
switch 42 shown in FIG. 5 to apply supply voltage to the control
circuit 54. With the water surface 67 above the predetermined level
L (FIG. 4), the float 52 maintains the upper end 64 in operative
engagement with the arms 60 to close the switch 53 and thereby
short the resistor R1. The output signal provided by shorting of
the resistor R1 produces conduction of the transistor A1 to
sequentially produce conduction of the transistors Q2, Q3, Q4.
Resultant current flow through the relay 99 closes the contacts 98
to energize the fan 40 through the closed on-off switch 42.
In response to a decrease of water volume 68 that brings the
surface 67 below the predetermined level L, the float actuator 52
moves downwardly into an inactivating position that eliminates
operative engagement between the upper end 64 and the arm 60. The
resultant opening of the switch 53 eliminates the output signal
provided by the shorted resistor R1 and renders the transistor Q1
non-conductive. That in turn renders the transistors Q2-Q4
non-conductive and deenergizes the relay 99 to open the contacts 98
and eliminate the flow of electrical current from the AC source 94
to the blower 40. However, turn-off of the transistor Q1 is delayed
for a given delay period established by the time constant of the
first delay circuit R3, C1, R4. That delay prevents erratic on-off
cycling of the contacts 98. Such erratic operation could result
from wave motion at the surface 67 of the water 68 caused, for
example, by mechanical vibration. A second delay period is provided
by the time constant of the second delay circuit RS, C2, R7
connected to the base of the transistor Q3. Preferably, the first
and second delay circuits C1, R3, R4 and C2, R7, RS, respectively,
are tuned to different frequency ranges so as to eliminate
different noise inputs to the controlled relay 99.
Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is to be
understood, therefore, that the invention can be practiced
otherwise than as specifically described.
* * * * *