USRE35153E - Humidifier with float activated water level responsive turn off - Google Patents

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.

Description

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.

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

Ahumidifier unit 11 includes awater storage tank 12 and anevaporator housing 13 supported in juxtaposition on abase 14. As shown most clearly in FIG. 3, thebase 14 includes abottom wall 15 and side walls 16-19 that together define areservoir 21. Projecting inwardly from each of the base side walls 16-18 in a region below theevaporator housing 13 is a rectangularly shaped, horizontally orientedbracket 22. Each of thebrackets 22 retains awick element 23 having aframework 24 forming a plurality of compartments each filled with a suitable absorbantcapillary wick material 25. Alower supply portion 26 of eachwick element 23 is positioned below itshorizontal retaining bracket 22 within thereservoir 21 while anupper evaporation portion 27 thereof is disposed above itsbracket 22 and above thereservoir 21. Projecting upwardly from the bottom of thebase 14 is a stem 28, the purpose of which is described hereinafter.

Theevaporator housing 13 is formed by side walls 31-34 and atop wall 35 and has anopen bottom end 36 opening into thereservoir 21. Supporting thebottom end 36 of thehousing 13 is aninternal shoulder 37 on thebase 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 ofinlet opening slots 38 while a plurality ofdischarge opening slots 39 are formed in thetop wall 35. The interior of theevaporator housing 13 forms parallel air flow paths extending between theinlet slots 38 in each of the housing side walls 31-33 and thedischarge slots 39 in thetop wall 35. Supported by thetop wall 35 and extending into theevaporator housing 13 is ablower assembly 41 that is controlled by an on-off switch 42.

As illustrated in FIG. 4 thehumidifier 11 is provided with liquid level responsive shut-offsystem 51. Included in thesystem 51 is an elongated, buoyantactuator float element 52 and anelectrical switch 53 actuated thereby, and acontrol circuit 54. Theswitch 53 andcontrol circuit 54 are enclosed in ahousing 56 supported by thesidewall 34 of theevaporator housing 13. Connecting theelectrical switch 53 to thecontrol circuit 54 areelectrical leads 57, 58. Thecontrol circuit 54 is connected also to themotor 41 and the on-offswitch 42 by anelectrical cable 59. Preferably, theswitch 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 anactivator lever arm 60. Retaining a buoyantlower end 61 of theactuator element 52 is areceptacle 62 extending upwardly from thebottom wall 15 of thebase 14. The oppositeupper end 64 of theactuator element 52 extends through an opening 65 in abottom wall 66 of the housing

In response to changes in the level of anupper surface 67 of a liquid volume 68 in thereservoir 21, thebuoyant actuator 52 moves either upwardly or downwardly in a path guided by aguide bracket 69 supported by thesidewall 34 of theevaporator housing 13. With theupper surface 67 of the liquid volume 68 at a predetermined level L or above, theupper end 64 of theactuator element 52 is moved into an activating position engaging thelever arm 60 and moving theswitch 53 into its active closed condition. However, at levels of theupper surface 67 less than the predetermined level L, theactuator element 52 floats downwardly to move theupper end 64 into an inactivating position that eliminates forcible engagement with thelever arm 60. Theswitch 53 is thereby induced into its inactive open condition. Also, regardless of the level of theupper surface 67 of the liquid volume 68, relative separating movement between theupper end 64 of the actuatingelement 52 and 40 theswitch 53 resulting from removal of theevaporation housing 13 from thebase 14 will cause theswitch 53 to assume its inactive open condition.

As shown in FIG. 4, thecontrol circuit 54 includes a plurality of interconnected transistors Q1-Q4 that receive DC power from a fullwave rectifier bridge 91. Supplying therectifier bridge 91 is the secondary of atransformer 93 having a primary connected to anAC 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 arelay 99.Contacts 98 of therelay 99 and the manually operated on-offswitch 42 connect themotor 41 of thefan blower 40 to theAC supply 94.

OPERATION

To prepare thehumidifier 11 for use, thetank 12 is removed from thebase 14 and thereservoir 21 is filled with water. In addition, thetank 12 is filled and then inverted and positioned on thebase 14. Water from thetank 12 flows through a control valve (not shown) into thereservoir 21. As long as a supply of water exists in thetank 12, theupper surface 67 of the water volume 68 is retained at a desired level. Operation of thesupply 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 thehumidifier unit 11, one of thewick elements 23 is appropriately positioned within each of thebrackets 22 on the base 14 after removal of thehousing 13. As shown in FIG. 3, with thewick element 23 properly positioned, itssupply portion 26 includes an outer surface disposed directly adjacent and parallel to the base side wall 16. Also an outer surface of theevaporator portion 27 of thewick element 23 is disposed directly adjacent and parallel to theinlet slots 38 formed in thehousing side wall 31. Although for reasons of clarity, only asingle wick element 23 is shown in FIG. 3, it will be understood that an identical wick element will be similarly positioned in each of thebrackets 22. Consequently, the supply portion of eachwick element 23 will be below theupper surface 67 of the water volume 68 in thereservoir 21 while theevaporator portion 27 of eachelement 23 will lie above that level and directly in an air flow path between one set of theinlet slots 38 and thedischarge 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 thecontrol circuit 54. With thewater surface 67 above the predetermined level L (FIG. 4), thefloat 52 maintains theupper end 64 in operative engagement with thearms 60 to close theswitch 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 therelay 99 closes thecontacts 98 to energize thefan 40 through the closed on-off switch 42.

In response to a decrease of water volume 68 that brings thesurface 67 below the predetermined level L, thefloat actuator 52 moves downwardly into an inactivating position that eliminates operative engagement between theupper end 64 and thearm 60. The resultant opening of theswitch 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 therelay 99 to open thecontacts 98 and eliminate the flow of electrical current from theAC source 94 to theblower 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 thecontacts 98. Such erratic operation could result from wave motion at thesurface 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 controlledrelay 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.

Claims (17)

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.]..

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