Source: https://www.google.ca/patents/US2074265
Timestamp: 2018-01-24 02:02:04
Document Index: 676338595

Matched Legal Cases: ['art 26', 'arts 32', 'art 5', 'arts 56', 'arts 56', 'art 51', 'art 56', 'art 26']

Patent US2074265 - Air conditioning apparatus - Google Patents
www.google.cahttps://www.google.ca/patents/US2074265?utm_source=gb-gplus-sharePatent US2074265 - Air conditioning apparatus
Publication number US2074265 A
Publication date 16 Mar 1937
Filing date 25 Oct 1933
Priority date 25 Oct 1933
Publication number US 2074265 A, US 2074265A, US-A-2074265, US2074265 A, US2074265A
Inventors James B Kirby
Original Assignee Ind Improvements Inc
US 2074265 A
J. B. KIRBY AIR CONDITIONING APPARATUS Filed Oct. 25, 1933 2 SheetsSheet 1 INVENTOR James B. Ki rby March 16,1937. J. B. KIRBY 2,074,265-
AIR CONDITIONING APPARATUS Filed Oct. 25, 1933 2 Sheets$heet 2 INVENTOR James B. Kirk BY A Ai ATTOR Patented Mar. 16, ll37 amazes 7 ant connrrioninc arraaa'rns .lames 1E. Kirby, West lltichiield, Uhio, assignor to industrial improvements, incorporated, (Cleveland, Uhio, a corporation of @liio Application @ctober 25, 1933, Serial No. 695,135
9 Ulaims.
This invention relates to air treating or air conditioning apparatus for use in connection with automobiles, heating appliances, and as a separate unit for the treating of the air of confined I spaces or buildings.
This invention has for its objects the provision of a generally simplified, relatively small, compact, portable device for circulating, cleaning, heating, humidifying, cooling or otherwise treating the air of confined spaces or inhabited buildings; the provision of an inexpensive, relatively small air treating device which operates to clean, humidify or otherwise treat the air admitted to the interior of a closed automobile; the provision of an air treating device for use in connection with a heating appliance which operates to circulate, clean, humidify or otherwise treat the air which is heated by the appliance; the provision of an air treating apparatus adapted particularly for the removing of pollen and the cleaning of the air supply of a room or inhabited building so that the air admitted thereto is substantially free from pollen and other particles of solid matter suspended in the air; the provision of an air treating machine having a novel arrangement for the filtering and humidifying the air handled by the machine; the provision of an air treating machine having novel provisions for removal and collection of dust and dirt .par-
ticles from the air and for the easy disposal of such collected materials; the provision of an air treating apparatus having improved means for continuously and automatically removing the dust and dirt which are separated from the air dur- .;3 ing the operation of the machine; the provision of an air treating machine having an improved means for filtering the air which will not become clogged up or inoperative after extended periods of use by reason of its being arranged so as to continuously maintain itself clean and in an operable condition regardless of the amount of dirt it separates from the air; the provision of a generally simplified air treating machine'which is so arranged as to require a minimum amount 43 of care or skill in its operation; the provision of an air cleaning and humidifying device in which the humidifying liquid is also used in the process of removing dust and dirt particles from the air being treated; the provision of a humidifying device having novel means for the control and circulation forthe water used for humidification purposes; the provision of an air cleaning and humidifying device in which the cleaning and humidifying agent is continuously subjected to a filtering operation whereby dust and dirt extracted from the air are separated from the humidifying liquid; and the provision of a generally improved and simplifieddevice for forcibly circulating, cleansing and humidifying the air supply of an automobile regardless of the movement of the automobile.
Referring to the drawings, Figure 1 is a side elevational view, partly in section showing the details of my improved air treating apparatus.
Figure 2 is a viewsimilar to Figure l with the device rotated ninety degrees in clockwise direction.
Figure 3 is an enlarged detail sectional view taken on line 33, Figure 2.
Figure 4 is a sectional view taken on line i l, Figure 3 showing the details of the water supply valve.
Figure 5 is an enlarged sectional view taken on line 5-5, Figure 2 showing the details of the water feeding device, and
Figure 6 is a side elevational view, partly in section showing the application of the invention as an air treating devicefor automobiles.
The form of the invention illustrated by Figures 1 to 5 comprises a cabinet structure having a removable top i with air discharge openings 2 located in one or more of the sides thereof. The top I is carried on a rectangular casing having a side 3 which is removably secured thereto for facilitating access to the operating parts of the device. An adjoining side i of the casing is provided with an opening 5 within which there is provided a series of louvers 6, the purpose of which is to prevent the escape of water from the interior of the apparatus. The cabinet is completed by a side I opposite to the removable side 3 and a side 8 opposite to the side 4.
Within the hollow interior of thecasing or cabinet just described, there is provided in the upper part thereof a blower or air pump which comprises a driving motor I0 and an associated fan H which may be of the sirocco type, a fan of this type being preferred by reason of its abilty to handle large volumes of air in a quiet manner. The motor Ill is carried on standards I2 supported by a platform I3 located in the up- I per part of the cabinet.
The fan is surrounded by a snail-shaped housing 14 which discharges into a compartment i5 which is formed in part by a wall l6 located adjacent to and spaced from the casing wall 8. The upper part of the compartment I5 is in communication with the outlet openings 2 provided Bill in the cabinet cover I. The motor Ill is located in a compartment H which has an opening I8 at its bottom for incoming air which passes to the center of the fan from whence it is discharged into the fan case l4.
Beneath the motor and fan there is located a filtering and humidifying device which comprises in the present case a perforate drum or cylinder 20 which may be in the form of a wire mesh screen or any other material suitable for the intended purpose. The cylindrical screen'is carried by a shaft 2| which is mounted for rotation in the bearings 22, 23 fixedly carried by the cabinet structure. An imperforate circular plate 24 is provided to close off one end of the drum whereas the opposite end of the drum is open for the passage of air.
The humidifying and washing action of the device is increased by the use of a double screen on the drum as is best shown in Figure 3. It is to be understood, however, that a single screen might be used on the drum in which case it would probably be desirable to use a somewhat finer mesh screen than is used'when the drum employs two screens.
The rim 25 of the open end of the drum or cylinder is maintained in closely spaced relation with respect to an apertured wall part 26 located inside the cabinet. The opening of this wall part registers with the opening defined by the open end of the cylinder. The shaft 2| carriesa pair of pulleys 21 and 28 at the shaft end which is adjacent to the open end of the cylinder. The pulley 28 is connected by a belt 30 to a pulley 3| which is fixed on the end of the motor shaft opposite to the fan The motor is secured to the standards |2 by means of relatively flexible frame parts 32, which are secured at one end to each of the ends of the casing of the motor Ill. The flexible supporting members 32 are secured at their other ends to relatively rigid frame members 33 which in turn engage with rubber bushing 34 which frictionally engage the reduced upper ends 35 of the supporting columns l2. This mounting permits the motor as a whole to have a slight amount of freedom of movement so as to prevent the transmission of the motor vibrations to the casing of the device.
The pulley 21 is connected by means of a perforated belt 36 to a pulley 31 which is rotatably carried on a supporting pin 38. The lower part of the pulley 3 terminates a slight distance above the bottom to one side of a removable water holding pan 40. This pan has an edge 4| formed by an extension of one of the side walls 44 thereof and such edge rests in a groove provided in a ledge 42 of the cabinet structure. The end of the pan opposite to the edge 4| is flexibly supported by means of a spring 43 so that the pan can move about the edge 4| for the purpose of controlling the supplying of water to the pan.
A rubber block 45 is secured at the upper part of the pan wall 44 by means of an apertured plate 46. Opposite to the block 45 there is provided a ported fitting 41 having a discharge outlet facing the rubber block 45. The stated outlet connects with a passageway which is provided in the fitting 41 and. which passageway is connected at its other end by means of a hose or conduit 48 to a water supply tank 50 located in the upper part of the cabinet.
Access to the container 50 can be had upon the removal of the cabinet coverl so that the water supply of the device can be readily replenished.
When the water in the pan 40 falls below a predetermined level, the spring 43 serves to tilt the pan about its edge 4| to uncover the discharge outlet of the fitting 41 and thus supply more water to the pan. When a predetermined amount of water is carried by the pan the weight of such water compresses the spring 43 and forces the rubber block 45 into engagement with the discharge outlet of the fitting 41 thereby cutting off the supply of water to the pan until such time as its level is reduced to the point where the weight of the water will again allow the spring 42 to shift the pan to a position where the block 45 is moved away from the outlet port of the fitting 41.
The pan 40 can be readily removed from the device after removal of the side wall 3 of the casing has been effected. The removal of the pan 4|] is accomplished by sliding it to the left as viewed in Figure 2 and when the wall part 5| of the pan has passed the end 52 of the ledge 42 the pan can be dropped down a slight distance to permit the top of its end wall 5| to pass beneath the pulley 31 and the valve fitting 41, whereupon the pan can be removed for cleaning or other purposes.
The belt 36 is provided with a plurality of more or less regularly spaced apertures 53 for the purpose of facilitating the conveyance of water from the lower pan 40 to the drum 20 of the device. The pulley 21 is provided with a peripheral groove 54 which also serves to facilitate the tangential discharge of water from that part of the belt which is in contact with the upper pulley 21.
The belt 36 is concealed and guarded on one side by a. wall or shield 55 which is rigid with the cabinet. The lower end of the shield 55 carries the bearing pin 38 of the pulley 31 and it also has laterally extending wall parts 56, 51, and 58. The wall parts 56 and 51 are parallel and closely spaced with respect to each other so as to provide a passageway for the upward traveling side of the belt. Water dripping off the belt onto the wall part 51 will be returned in a quiet manner to the pan 40. This arrangement also facilitates the conveyance of water by the belt to the upper part of the apparatus as some of the water thrown onto the wall part 56 will eventually find its way back to the belt.
To one side of the upper pulley 21. there is provided a trough 59 which is arranged to catch water thrown off of the pulley and belt during the operation of the device. tends substantially from one end to the other of the drum 20 and it is provided with spaced holes 60 at its bottom for the escape of the water which it collects. The escaping water from the trough 59 drips onto a plate 6| where it spreads out more or less evenly over the length of the plate and then flows to the inner surface of the inner screen of the drum 20. In this manner water is passed continuously through the aperture of the screens in an outward direction.
Beneath the drum 20 there is provided a filter 62 which is carried in the bottom of a. generally rectangular supporting frame 63 having a handle 64. The frame 63 is slidably supported on runners or guideways 65 carried by the cabinet of the machine. The filter 62 may be formed from a fine mesh cloth screen orfrom any other material suitable for the purpose intended and with its frame 63 it constitutes a litter receptacle for dust and dirt collected by the water passing therethrough.
The trough 59 ex-' a partially opened window, so that substantially all of the air admitted by way of the open window passes through the device and is there treated before it is discharged into the room in which the device is located.
When the'motor I0 is connected to a source of electric current supply, the fan II and the belts 30 and 36 are thereby driven. The belt 3!! drives the drum at a relatively high speed and the movement of the belt 34 serves to transfer water from the pan til to the screen of the drum ill as aforesaid. Due to centrifugal force, the water passes through the screen of the drum and is thrown into the compartment surrounding the drum in an atomized or rather finely divided state. This water then passes to the filter screen by way of the apertured bottom wall it of the humidifier compartment and in this manner dust and dirt are separated from the water before it is returned to the pan til.
This operation is substantially continuous and the air drawn by the fan it through the space defined by the open window passes through the opening 5, thence through the screen of the drum 20 discharging at the open end of the drum into the compartment ll by way of the opening it. The humidified and cleaned air then passes to the fan H which forces it into the compartment if, from which it escapes by way of the openings 2 into the space surrounding the apparatus.
After the device has been operated for a considerable period of time the accumulated dirt col- 40 lected by the filter can be readily disposed of by simply removing the tray formed by the frame 63 and its filter screen '62 whereupon such accumulated dirt canbe dumped at a convenient place. The filter can be washed off by inverting 45 it under a running stream of water and then replacing it in the cabinet.
The supply of water for the devicecan be eas-' ily replenished by simply removing the casing cover I whereupon the upper pan 50 is uncovered 50 and a suitable quantity of water can then be poured into this pan. This water is automatically fed to the lower pan by the gravity control valve which is made up of the pan 40 and the rubber block and the fitting 41.
The operation of this device involves several novel features among which is the directing of the air stream in a generally opposite direction to the movement of the water which is used for the humidification of such air. The belt 36 is op erated at a relatively high speed so that an appreciable quantity of water is fed to the inner sur- Whatever moisture is present in the air at the discharge outlet of the device is largely in the gaseous state in the form of water vapor. The louvers 6 prevent the escape of water from the cabinet by way of the air inlet opening 5. The
manifold or passageway formed by the wall part air in the space in which the device is located and if it is desired to heat such air the opening 5 can be located adjacent to a radiator or other heating device in which case the air is heated, humidified, filtered and circulated by the device.
In warm weather with the device operated in connection with air supplied by way of a window opening, the evaporation of the water used with the device tends to reduce the temperature of the air in which case the apparatus operates as an air cooling air filtering and air circulating device. 'The cooling effect of the device can also beincreased by placing ice in the upper and lower water pans.
In the form of the invention shown in Figure 6 the numeral iii represents the cowl of an automobile beneath which there is slidably fitted a small water holding tray M which rotatabiy carries a pulley 112. A perforated drum i3 is carried on a shaft which is rotatabiy mounted in suitable support bearings (not shown). The drum i3 is of similar construction to the drum of the device shown in Figure 1. One end of the drum is closed by an imperforate wall M, the other end of the drum constitutes the discharge outlet of the device.
The side wall of the drum I3 is surrounded by a spiral housing 715 having a drain opening 16 at the bottom thereof for the return of water to the pan M. The drum is provided with a pulley ll similar to the pulley 27 shown in connec-' tion with Figure 1 and a perforated belt 18 similar to the belt shown in Figure l connects the pulleys l2 and H to each other. A water trough 19 having holes in its bottom is carried at one side of the pulley ill to catch water thrown off the belt at this point and to transfer such water to the drum 13 in the manner previously described.
Fan blades are provided on the periphery of the drum. The snail-shaped housing l5 communicates tangentially with a conduit 8| which terminates in a funnel-shaped opening 82 facing the fan 83 of the automobile engine 84. By reason of this arrangement the fan 83 forces air into the passageway of the conduit 8| which directs it against the blades 80 of .the drum 13, thus imparting a relatively rapid rotational movement of the drum.
After impinging against the fan blades the air passes through the screen and then out of the open end of the drum and into the automobile. The movement imparted to the belt 18 by the rotation of the drum causes water to be transferred from the pan H to the trough I9 from where it drips onto the inner surface of the perforated drum and passes through the drum and drains from the housing 15 by way of the opening 16.
The opening it is located just above a filter screen 85 carried in a frame 86 which is removably carried above the water pan ll so that dirt and dust are removed from the water before it is returned to the pan H. The air supplied to the interior of the car is thus filtered and humidified and in warm weather its temperature is lowered by reason of the evaporation of the water used in connection with its treatment. If desired a suitable closure (not shown) can be provided for the outlet side of the device or a butterfly valve 81 in the conduit Bl having an operating rod 88 extending into the interior of the car can be used so that thesupplying of air to the interior of the car can be controlled by the occupants of the car.
In all of the foregoing arrangements there is no substantial tendency for the air to pick up large water particles by reason of its flow being in a direction opposite to the movement of the water and the moisture which is added to the air is principally in a gaseous state in the form of water vapor. Better cleaning of the air also results by preventing the air from carrying water particles as such water particles often serve as nuclei for the collection of dust and dirt particles.
This invention also readily lends itself to the scenting, deodorizing, disinfecting or chemical treatment of air, as suitable substances for such purposes can be readily incorporated in the water supply and such water then acts and can be used as the distributing or disseminating agent for Water soluble substances many of which might not be readily volatilizable in air.
The various forms of the air conditioning apparatus herein illustrated are capable of handling and treating relatively large volumes of air with the expenditure of relatively small amounts of energy. This result is accomplished by the use of relatively unrestricted air passageways which are maintained at all times in such condition. In a great many air conditioning devices filters are used which become clogged or filled with dirt within a short time, thus requir ing the frequent cleaning or replacement of such filters. The filters used in connection with the devices shown herein are not only highly porous but they are also kept so by continuously passing clean water through the filter in a direction op- DQSite to that of the air flow.
The efiiciency of devices employing filters which require cleaning or replacement decreases from day to day as the filters become more and more filled with dirt and if attention and care is not given to the filters of the device it will eventually become wholly inoperative for the purpose intended. The filters used in carrying out this invention require little or no attention and they operate at all times at their maximum efiiciency.
The use of a screen for air filtering purposes accomplishes several highly desirable objects. In the first place a screen may be readily wetted to effect the exposure of a large surface of water to the air. A wet filter forms a much better filtering device for the removal of dust and dirt from air than would a dry filter as the dust and dirt particles are more easily trapped and removed from the air by a wet surface than they are by a dry surface.
By passing the air through a screen the air is temporarily broken up into as many paths as there are openings in the screen. By revolving the screen at a rather rapid rate a larger percentage of the air passing through the screen will come in contact with the wetted surfaces of the screen than would if the screen were stationary. By the use of a moving or revolving screen the water used in the air treating process can be readily atomized or broken up into small particles which makes it more efiicient both for cleaning and humidifying purposes.
In all of the devices disclosed herein it should be noted that the air is exposed to water spray and suspended particles of water at one side and at one side only of the screen. The rapidly moving screen operates to remove from the air, paraovaaee ticles of water that might be picked up by the air in passing through the space surrounding the screen. The devices shown herein are also very economical in the use of water and in some of the forms of the invention the water can be used over and over again by reason of the provision of a filtering device for removing the dust and dirt collected by the water.
The speed at which the drum is rotated and the force of the suction fan or blower are two of the factors which determine the fineness of the mesh of the screen which can be used. It is preferred to use a screen of such mesh so that a film of water will not be maintained in its open spaces during the operation of the device and thus a relatively free and unobstructed path is provided for the air by the screen.
It is possible by'the use of a fine mesh screen, to maintain a film of water on the screen despite the "air pressure and the centrifugal force both of which are operating to break down the film. Under such conditions the screen would in effect constitute an imperforate cylinder which however would permit the transference of water through its surface as'this does not require the breaking of the film. It might be advantageous for some purposes to employ this form of constructionin which case passageways could be provided adjacent to the ends of the drum for the escape of the air which has been directed against the curved side wall of the drum. In the case of the device shown in Figure 1 the space between the end of the drum and the wall part 26 could be increased or the solid end wall 2 5 could be replaced by a spider (not shown) or any other form of construction which would permitthe passage of air at this point.
By directing the air against such a moving wetted surface even though the surface be imperforate it will operate to remove a very considerable portion of the dust and dirt out of the air by reason of the dust and dirt impinging against the wetted surface where the dust and dirt particles are trapped by the water. The surface is maintained clean by the constant supplying of water to the interior of the drum.
It is also within the contemplation of this invention to employ a drum having a side wall formed from a solid air impervious material which could be continuously wetted by a device similar to the arrangement shown in Figure 1 with the difierence, however, that thev water would be fed to-the outer surface of the drum rather than to the inner surface as shown and while such device would lack the advantages resulting from the passing air through a screen in one direction and water in the opposite direction, it might serve sufficiently well as a humidifier and air cleaning device for some purposes.
Furthermore it is to be understood that the particular forms of apparatus shown and described, and the particular procedure set forth are presented for purposes of explanation and that various modifications of said apparatus and procedure can be made without departure from this invention as described in the appended claims.
1. Air treating apparatus comprising a casing structure in the form of a hollow cabinet having air inlet and air outlet openings and a communicating passageway therebetween, means for effecting the passage of air through said cabinet by way of the inlet and outlet openings thereof,
a water supply reservoir in the bottom of said cabinet, a humidifying device located above said reservoir, belt means for transferring water from said reservoir to said humidifying device and returning unevaporated water from the humidifying device to the reservoir for use over again continuously during the operation of the apparatus, means for filtering the unevaporated water before it is returned to said reservoir, and a support for said filtering means accessible exteriorly of the cabinet whereby the filter may be removed without disturbing the rest of the apparatus.
2. Air treating apparatus comprising a casing structure in the form of a hollow cabinet having air inlet and air outlet openings and a communicating passageway therebetween, means inside said cabinet for drawing air into the inlet opening and discharging it from the outlet opening thereof, a water supply reservoir in the bottom of said cabinet, a humidifying device located above said reservoir, means for transferring water from said reservoir to said humidifying device and returning the unevaporated water to the reservoir for use over again continuously during the operation of the apparatus, means for filtering the unevaporated water before it is returned to said reservoir, and a support for said filtering means in the form of a frame mounted for slidable movement by way of an opening in the side of said cabinet, said frame having a handle outside the cabinet to facilitate its manipulation.
3. An air treating device comprisinga hollow cabinet or casing structure having air inlet and air outlet openings and a communicating pas sageway therebetween, means including a motor andfan in the upper part of said cabinet for circulating air through said cabinet, a Water supply reservoir in the bottom of said cabinet, at humidifying device between said reservoir and said air circulating means, a belt connecting said humidifying device to said motor, conduit means fixed with respect to a part of said cabinet for conveying water to said humidifying device, and
belt means for raising water from said reservoir and delivering it to said conduit means.
4. An air treating device comprising a hollow cabinet or casing structure having air inlet and air outlet openings and a communicating passageway therebetween, means including a motor and fan in the upper part of said cabinet for circulating air through said cabinet, a water supply reservoir in the bottom of said cabinet, a humidifying device between said reservoir and said air circulating means, a belt connecting said humidifying device to said motor, conduit means fixed with respect to a part of said cabinet for conveying water to said humidifying device, and belt means for raising water from said reservoir and discharging it centrifugally into said conduit means, said cabinet having a readily removable section for permitting access to said humidifying device and motor.
5. An air treating device comprising a hollow cabinet or casing structure having air inlet and air outlet openings and a communicatingpassageway therebetween, means including a motor and fan in the upper part of said cabinet for circulating air through said cabinet a water supply reservoir in the bottom of said cabinet, a humidifying device between said reservoir and said air circulating means, a belt connecting said humidifying device to said motor, and means for conveying water from said reservoir to said humidifying device, said cabinet having a readily removable wall section to permit access to said air circulating means, said humidifying device and the connecting belt therebetween.
6. An air treating device comprising a hollow cabinet or casing structure having air inlet and air outlet openings and a communicating passageway therebetween, means including a motor and fan in the upper part of said'cabinet for circulating air through said cabinet, a water supply'reservoir in the bottom of said cabinet, a humidifying device between said reservoir and said air circulating means, a belt connecting said humidifying device to said motor, and means for conveying water from' said reservoir to said humidifying device, said cabinet having a horizontally disposed partition between said air circulating means and said humidifying device and a communicating passageway extending around said partition between the upper and lower portions of the cabinetv 7. An air treating device comprising a hollow cabinet or casing structure having air inlet and air outlet openings and a communicating passageway therebetween, a water container in the upper part of said cabinet, a conduit leading from said container to the lower part of said cabinet, a removable top for said cabinet overlying said container, means for circulating and humidifying air in said cabinet including a water supply reservoir pivotally supported at one end and resiliently supported at the other end so that the reservoir may move about its pivot in accordance with the volume of water it contains, and means responsive to the movements of said reservoir and operatively associated with said conduit for controlling the supply of water to said reservoir.
8. An air treating device comprising a hollow cabinet or casing structure having air inlet and air outlet openings and a communicating passageway therebetween, means for circulating and humidifying air in said cabinet including a water supply reservoir pivotally supported at one end and resiliently supported at the other end so that the reservoir may move about its pivot in accordance with the volume of water it contains, and means including a closure pad fixed to the side of said reservoir and a water supply conduit fixed with respect to said cabinet and having an opening presented to said pad and cooperating therewith for controlling the supplying of water to said reservoir.
9. Air treating apparatus comprising a casing structure in the form'of a hollow cabinet having air inlet and air outlet openings and a communicating passageway therebetween, means for effecting the passage of air through said cabinet by way of the inlet and outlet openings thereof, a water supply reservoir in said cabinet, a humidifying device located in said cabinet, means for transferring water from said reservoir to said humidifying device and returning unevaporated water from the humidifying device to the reservoir for use over again continuously during the operation of the apparatus, and means for filtering the unevaporated water before it is returned to said reservoir including a part accessible exteriorly of the cabinet whereby the filter may be removed without disturbing the rest of the apparatus.
JAMES B. KIRBY.
US2421557 * 2 Jun 1945 3 Jun 1947 Haniquet George Hydro-vapor air conditioner
US2657026 * 5 Jan 1951 27 Oct 1953 Richter Sr Charles Frederick Evaporation type vehicle cleaning and cooling unit
US3869529 * 30 Aug 1972 4 Mar 1975 Donald T Follette Air conditioning apparatus
US3951625 * 27 Feb 1975 20 Apr 1976 Follette Donald T Air conditioning apparatus
U.S. Classification 261/90
International Classification F24F6/06
Cooperative Classification F24F6/06
European Classification F24F6/06