US3730497A

US3730497A - Portable humidifier

Info

Publication number: US3730497A
Application number: US00112253A
Authority: US
Inventors: A Schmitt; L Spaeth
Original assignee: West Bend Co
Current assignee: Bemis Manufacturing Co; West Bend Co
Priority date: 1971-02-03
Filing date: 1971-02-03
Publication date: 1973-05-01
Anticipated expiration: 1990-05-01
Also published as: CA936799A

Abstract

A lightweight inexpensive portable humidifier has an air coupling drive between a motor driven fan and a louvered wheel carrying a filter. A fan housing directs the flow of air from the fan to a restricted area of the filter and louvered wheel. Part of the air goes through the filter and then to the blades or louvers of the wheel and part of the air flows directly against such blades. As the wheel rotates the filter passes through a supply of water in a casing having a water storage reservoir and as the air goes through the filter moisture is evaporated into the air. The fan, fan housing, driving motor, saddle block bearings for the shaft of the wheel and float arm are all mounted on a chassis to form a unit which is self-supporting in the water containing casing and is removable therefrom to operate, without the wheel, externally of such casing. When water falls below a low point the float arm operates a brake to stop the wheel from rotating without stopping the fan.

Description

United States Patent [1 1 Schmitt et al. 51 May 11., 11973 PORTABLE HUMIDIFIER Primary Examiner-Tim R. Miles Att0rney.lohn W. Michael, Gerrit D. Foster, Bayard [75] lnvemors' ggtg g 'a g d Spaeth H. Michael, Paul R. Puerner, Joseph A. Gemignani, Robert E. Clemency, Andrew 0. Riteris, Glenn A. [73] Assignee: The West ligand Company, West Buseand Spencer B. Michael Bend, Wis. 22 Filed: Feb. 3, 1971 [57] ABSTRACT Appl. No.2 112,253

3 Claims, 5 Drawing Figures PORTABLE HUMIDIFIER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to a small inexpensive lightweight portable humidifier designed primarily for residential use which employs an air coupling drive between a motor driven fan and a freely rotatable filter.

2. Description of the Prior Art Humidifiers for home use employing air coupling drives are described and shown in US. Pat. Nos. 2,173,645 and 2,210,354. However in both of these, the filter is in the form of a fan which is positioned coaxially with a motor driven fan. These arrangements have a tremendous loss of efficiency and will not operate except by driving the blower fan at high and noisy speeds. Neither of these patents show the flow of air from the driven fan to a restricted area of the filterfan.

Patent searches in the humidifier field failed to uncover any prior art showing: (1) the operation ofa brake to stop rotation of 'the freely rotating filter when water level becomes too low; and (2) the motor driven fan and other componentsmounted on a chassis to form a unit which may be removed from the casing, placed on a level surface and operated exteriorly of such casing.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawing: FIG 1 isa top plan view of ahumidifier embodying the present invention, part of the outlet grills being .broken away to expose some of the internal components;

FIG. 2 is a sectional view taken on the line 2-2 of FIG. is an enlarged sectional view taken on the line 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In order-to illustrate this invention it is incorporated I in a compact lightweight portable humidifier. The humidifier is adapted to be placed on a table top or other flat surface. To standardize and simplify the description of the humidifier, that side of the casing shown to the right in FIG. 3 will be identified as rear while the side to the left as shown in such figure will be identified as front.

An essential feature of this invention resides in the relationship between the motor driven fan and a louvered wheel. Such wheel may also be termed a deflector. Thefan is placed above a water storage reservoir in a casing and the louvered wheel and a water absorbent filter carried by it each extending both into and above the water storage reservoir. The air forced out from the fan is confined so as to strike only a restricted portion of the filter and louvered wheel. This arrangement provides asufficient amount of coupling to start the wheel rotating.

Referring to the drawings by reference numerals the humidifier includes a casing 10 of rectangular shape with an open top. The casing 10 is molded impact polystyrene. The top of the casing 10 is designed to support air deflecting grills 12 of well-known design. The rear wall of the casing 10 has an air intake grill l4 molded-in as an integral part of the casing. The lower part of the casing defines a reservoir for the storage of water.

The moving components of the humidifier hereinafter described in detail are all mounted on a metal chassis 16 which is removable as a unit from the casing 10 when the grills l2 and retaining screws are removed. This chassis includes a stainless steel stand 18 which makes the chassis self-supporting either within the casing 10 or exteriorly thereof on a flat surface. When positioned in the casing 10 the sides of the bottom edges of the stand are held by two sets of spaced

ribs

20 and 22. A pair of ribs 24 engage the front ends of the sides of the stand to properly position it with respect to the rear of the casing 10. The stand 18 has a shoulder 19 visible from the top of the casing to indicate a normal full water level.

The front wall of the chassis 16 has a projecting tubular neck 26 in which is mounted a tubular fan housing 28. This fan housing is positioned entirely above the normal full water level marking shoulder 19 which defines the water reservoir and extends rearwardly from the front wall of the chassis 16 to form a tunnel which directs the flow of air to a confined or restricted area of a freely rotating louvered wheel carrying a disclike filter pad. FIGS. 2 and 3 show the relationship of the area of outlet of the fan housing to the area of the louver wheel.

Extending rearwardly from the front wall of the chassis is a motor mounting frame 30 which consists of a pair of legs welded to a pair of mounting plates. The forward ends of such legs are mounted to the four corner areas of the front wall of the chassis outside fan housing 28 by conventional shock absorbing rubber mountings. t

Mounted by machine screws to the mounting plates is an A.C. electric motor 32 of conventional design to produce 1,500 r.p.m. at volts A.C. The motor is positioned so that its drive shaft extends forwardly into the fan housing 28 concentrically thereof. The drive shaft carries a five bladed aluminum fan 34 which is confined to rotate within the fan housing with minimal clearance. Upon rotation in the direction indicated the fan draws air from the atmosphere, in which the humidifier is placed, inwardly through the intake grill 14 thence into the fan housing and forwardly against a restricted area of a louvered wheel and a filter pad carried by it.

The louvered wheel 36 is shaped as shown (see particularly FIGS. 4 and 5) and is a polystyrene molded part. It has 48 blades 38 equally angularly disposed about its hub. The axial width of these blades 38 increases in increments radially outward so that there is more effective area nearer the perimeter thus providing a greater torque. The wheel 36 has an outer rearwardly extending circumferential flange 40 within which is mounted a disc-like filter pad 42. This pad has a large central opening 44. The pad is preferably polyurethane foam with a 10 pore rating and a thickness of approximately three-eighths of an inch. The pad 42 is held within the flange 40 by projecting tabs 46. The flow of air from the fan 34 also contributes to holding the filter pad 42 in place on the wheel 36. It may be easily withdrawn for cleaning or replacement. Both the wheel and the pad have portions above and below the normal full water level marking shoulder 19 which defines a water storage reservoir. When the wheel 36 rotates the filter 42 will pass through a supply of water in the lower part of the casing 10. While passing through the water it will absorb water. When air is forced through the wetted filter as the filter passes by the front end of the fan housing 28 it will evaporate moisture from the filter and increase the humidity of the air as it passes out of the filter.

In order to mount the louver wheel 36 for free rotation and still have it easily removable for cleaning or changing the filter pad, the wheel is provided with a stainless steel shaft 48 which projects from both ends of its hub. A support 50 of the shape shown in FIGS. 1, 2 and 3 has its rearwardly extending legs secured to the chassis 16. This support extends outwardly around the wheel 36 and has a forward portion extending over the front face of the wheel 36 in spaced relation thereto. At approximately the center of such forward portion there is provided a notch in which is mounted a saddle type outer bearing 52. An inner bearing 54 of the same type as hearing 52 is positioned rearwardly of the wheel 36 and is fastened by a bearing support member to chassis 16. The

bearings

52 and 54 are preferably molded acetal resin. They are axially aligned and mounted above the normal full water level marking shoulder 19. The combination of the plastic bearings and the metal shaft resists the accumulation of friction enhancing lime deposits. Thus the wheel continues to rotate freely and by reason of the U-shaped saddle construction of the

bearings

52 and 54 may be readily lifted out of the casing 10.

It is a feature of this invention that the

bearings

52 and 54 are positioned below the axis of the shaft of motor 32 and above the shoulder 19 which marks the normal full water level. The diameter of the fan housing 28 is only slightly larger, say one-halfinch, than half the diameter of .the flange40 on the wheel 36. Thus the areaof the blades 38 of the wheel 36 to which the air is directed by the fan housing is very restricted in relationship to the total area of such blades. Furthermore the outlet of the fan housing 28 being non-concentric with the wheel 36, the force from the fan 34 will be most efficiently transmitted to the blades 38 of the wheel 36 with a minimal loss of energy. The distance between the front end of the fan housing 28 and the rear edges of the blades 38 is preferably small, say in the neighborhood of five-eighths of an inch. This also aids in obtaining good energy transfer from the fan to the wheel.

Another feature of this invention is the size and location of the circular opening 44 in the filter pad 42. This opening, centrally located, is large enough so that approximately one-quarter of the area of the opening exposed to the mouth of the fan housing 28 will be directly in line with the wheel blades 38 and the volume of air there delivered will not pass through the pores of the filter 42. However this non-filtered portion of the delivered air engages the blades 38 at their smaller axial width and shorter radial extension. The effective energy transmitted at such portion will be sufficient to overcome the inertia of the wheel and start its rotation.

While the velocity of flow of air from approximately the upper half of the fan housing will be lessened as it passes through the filter, it will engage the blades at their larger axial width and longer radial extension and effectuate an effective transfer of energy.

Another feature of this invention resides in providing a brake which will frictionally stop the free rotation of the wheel 36 and prevent it from increasing its speed of rotation when the water level in the water storage reservoir reaches a near empty state. Thus the remaining moisture in the pad and the water picked up by the flange 40 as it passes through the low level water will not be flung outwardly with some of it being projected through the grills 12 into the room where the humidifier is placed. To accomplish this braking action a float arm 56 has a bracket which is pivotally mounted on a stud 58 extending forwardly from the lower righthand (see FIG. 2) front face of the chassis 16. The bracket is retained on the stud by a conventional removable retainer. As shown in FIGS. 1 and 2, the arm 58 has at its lower end a polystyrene float 60. The upper end of the arm is offset and provided with a pad 62 which will bear against the outside of the flange 40 to stop the wheel 36 when the float drops to about the position indicated in FIG. 2. When the supply of water is replenished the float 60 will rise and disengage the pad 62 from the flange 40. The loss of water supply does not automatically stop the motor 32 and fan 34.

It has previously been described how the chassis and the moving components supported by it can be removed from the casing and operated exteriorly thereof. As the unit is raised from the casing the electric cord, its cord switch and the usual male plug are fed inwardly through a sufficiently large opening 64, see FIG. 1, in the intake grill 14 and will be removed with the unit so that it can be plugged in and operated as a mover of air. Before removing the unit it is best to first lift the wheel 36 from the casing 10.

Still another feature of this invention resides in the automatic balancing of the water to air ratio. When the water level in the casing 10 is high there will be a higher hydraulic friction which tends to keep the wheel 36 at a relatively slow r.p.m. As the water level drops the hydraulic friction decreases and r.p.m. of the wheel automatically increases. Thus the volume of water continuously presented to the flow of air for all effective purposes remains constant and the ratio of water to air is maintained proper and predetermined-during operation from high level to low level.

We claim:

1. A portable humidifier comprising:

a. a casing having a water storage reservoir in its base;

b. a motor driven fan in said casing positioned above said water storage reservoir;

c. a louvered wheel freely rotatably mounted in said casing and extending both above and into said water storage reservoir,;

. a filter pad associated with said louvered wheel on the upstream side thereof so hat as said wheel rotates the filter pad will pass downwardly into said water storage reservoir and upwardly to the path of air from said motor driven fan; and

i 6 e. a housing for said fan having an opening above the adapted to engage said louvered wheel when said axis of rotation of said pad in direct communicafloat descends in said water storage reservoir to tion with a restricted area of said filter pad on the n empty positionupstream side thereof. 3. A portable humidifier as defined in claim 1 2. A portable humidifier as defined in claim 1 5 whel'eil'll wh i said filter pad is circular with a centrally placed there is a pivotally mounted float arm having at one P l large enough to extend both above and end a float movable within said water storage Sald water storage reservolrreservoir and braking means at the other end 10

Claims

1. A portable humidifier comprising: a. a casing having a water storage reservoir in its base; b. a motor driven fan in said casing positioned above said water storage reservoir; c. a louvered wheel freely rotatably mounted in said casing and extending both above and into said water storage reservoir,; d. a filter pad associated with said louvered wheel on the upstream side thereof so hat as said wheel rotates the filter pad will pass downwardly into said water storage reservoir and upwardly to the path of air from said motor driven fan; and e. a housing for said fan having an opening above the axis of rotation of said pad in direct communication with a restricted area of said filter pad on the upstream side thereof.

2. A portable humidifier as defined in claim 1 wherein: there is a pivotally mounted float arm having at one end a float movable within said water storage reservoir and braking means at the other end adapted to engage said louvered wheel when said float descends in said water storage reservoir to near empty position.

3. A portable humidifier as defined in claim 1 wherein: said filter pad is circular with a centrally placed opening large enough to extend both above and into said water storage reservoir.