US2780826A

US2780826A - Air supported cleaner

Info

Publication number: US2780826A
Application number: US418512A
Authority: US
Inventors: Curtis C Coons; John C Montgomery
Original assignee: Hoover Co
Current assignee: Hoover Co
Priority date: 1954-03-25
Filing date: 1954-03-25
Publication date: 1957-02-12
Anticipated expiration: 1974-02-12
Also published as: BE536780A; GB767647A; US2814064A; GB777549A; FR68225E; FR1126989A; US2743787A; BE541908A

Description

Feb. 12, 1957 c. c. COONS ETAL AIR SUPPORTED CLEANER 5 Sheets-Sheet 1 Filed March 25, 1954 Fe. 12, 1957 c. c. COONS ET AL 2,780,826

AIR SUPPORTED CLEANER 3 Sheets-Sheet 2 Filed March 25, 1954 Feb. 12, 1957 Q c, co Ns L 2,780,826

AIR SUPPORTED CLEANER 3 Sheets-Sheet 3 Filed March 25, 1954 AIR SUPPORTED CLEANER ('lurtis C. Coons, North Canton, and John C. Montgomery, Gleveland, Ohio, assignors to The Hoover Company, North Canton, @hio, a corporation of Ohio Application March 25, 1954, Serial No. 413,5i2

23 Claims. (Cl. 15327) Our invention. relates to the art of suction cleaners and in particular to a novel means of supporting a cleaner upon a surface and providing for effortless movement of the cleaner about a supporting surface at the will of the operator to facilitate cleaning operations.

In a suction cleaner built according to our invention, the weight of the cleaner body is wholly or partially supported upon a cushion of air created by the air discharged from the cleaner body in the normal operation thereof. The cleaner exhaust air is entrapped between the cleaner body and a supporting surface in a space having an effective area on the cleaner body of a size such that a slight super-atmospheric pressure maintained in the entrapped body of air suflices to support the entire or the major portion of the weight of the cleaner upon an air cushion formed by the escaping air with the result that a very minute force applied to the cleaner body in any direction is suflicient to cause the same to move a very considerable distance across a carpet or other supporting surface. It has, for example, been found that a conventional type of so-called canister suction cleaner embodying our invention can be caused to slide a distance of five to ten feet across the carpet as the result of a slight push applied with the fingertips on the side thereof. Our invention embodies itself in several different forms, in some of which the entire weight of the cleaner is always supported on an air cushion while the cleaner is operating to discharge air through the clean air exhaust port in the body thereof. in another form of the invention all or a major part of the weight of the cleaner may be supported by an air cushion as described only when the operator desires to move the cleaner about from place to place.

in suction cleaners constructed according to our invention, the weight of the cleaner is wholly or partially supported upon an air cushion which is maintained by air discharging through the normal discharge ports of the cleaner body and there is a constant escape of air from the air cushion or supporting body of air either beneath the lower portions of the cleaner body which are normally in contact with the supporting surface or carpet or alternatively, there may be a constant escape of air through auxiliary escape ports provided for the purpose which are so related in size to the volumes of air normally expected to be discharged from the cleaner as to maintain a sufficient pressure in the cushioning body of air to support all or a major part of the weight of the cleaner.

It is a further characteristic of our invention wherein auxiliary discharge means are provided as mentioned hereinabove, that the size of the auxiliary escape ports may be so chosen with reference to the size and weight of the cleaner and air flow characteristics thereof, that only part of the weight of the cleaner is supported while the cleaning nozzle is in normal use; that is, in engagement with a fabric surface to be cleaned and the entire weight of the cleaner is supported on the air cushion when the nozzle is out of contact with the surface to be cleaned producing conditions of maximum air flow "atent 2,730,826 Patented Feb. 12, 1957 through the cleaner and maximum back pressure in the supporting air cushion whereby the operator may at Will convert the cleaner from a partially supported to a fully supported condition by merely lifting or rocking the nozzle with reference to the fabric being cleaned so as to open the nozzle to maximum extent to allow free air flow therethrough.

Further objects and advantages of our invention will become apparent as the description proceeds when taken in connection with the accompanying drawing wherein:

Figure l is a section elevational view of a known type of suction cleaner embodying our invention;

Figure 2 is a small scale view partly in section, il lustrating the cleaner of Figure 1 in operation and showing the manner in which the weight thereof is supported upon an air cushion;

Figure 3 is an elevational view partly in section, illustrating a modified form of the invention having metered discharge ports above the supporting surface;

Figure 4 is a side elevational view partly in section, illustrating a different type of suction cleaner embodying our invention; and

Figure 5 is a bottom plan view of the cushion cleaner illustrated in Figure 4.

Referring now to the drawing in detail and first to Figures 1 and 2 thereof, our invention is shown embodied in a suction cleaning apparatus comprising a main cylindrical casing l which is open at its upper and lower ends and is provided with inwardly projecting horizontal annular upper and lower flanges 2 and 3, respectively.

lnteriorly of the casing 1, a channel-shaped annular member 4 is provided which is suitably secured to the inner surface of casing 1 as by spot welding. The invetted channel-shaped member iis provided with an inwardly directed horizontal annular flange 5 which forms a supporting base for a power plant structure to be described hereinafter.

The apparatus is provided with a motor fan unit indicated generally by the reference character 6 which comprises a suction air fan of known type housed within the casing 7 and drivingly connected to an electrical drive motor 8. The housing 7 is so constructed that air drawn thereinto through the central air inlet opening 10 passes through the air pumps and over the motor 8 and then discharges around the lower portion of the motor as indicated by the arrows.

The power plant housing 6 is provided approximately centrally thereof with a laterally-projecting annular flange 9 which is received in a notched portion of an upper annular and resilient gasket 11 made of rubber or similar material and rests upon a lower similar gasket 12 which is seated upon the flange 5.

The motor fan unit is seated in the housing 1 with the fan at the upper portion thereof and the fan air inlet opening 10 facing upwardly. That portion of the power plant structure projecting above the gasket 11 is housed by a dish-shaped forarninous member 13 which is positioned in spaced relation to all portions of the power plant unit and is provided at its edge with a horizontal outwardly projecting annular flange 14 resting upon the upper surface of the gasket 11. Spaced studs 15 extend through the flange l4, gaskets 11 and 12, flange 5 and thread into nuts 16 secured to the undersurface of the flange 5 as by welding. When the studs 15 are drawn down through the nuts 16, the flange 1dis drawn toward the flange 5 which compresses the gaskets 11 and 12 between the flanges l4 and 5 and causes the same to grip the supporting flange 9 of the motor fan structure to retain those portions immovably and firmly in position but still to provide a resilient sound and shock-absorbing mounting therefor.

It is to be noted that as shown the motor fan unit 6 is positioned low within the casing 1 and substantially centrally of the periphery thereof whereby the center of gravity of the cleaner is positioned low in the casing 1 and substantially centrally of the projected base area.

It is apparent from a study of Figure 1 of the drawing that the interior of the casing 1 is divided by the power plant unit and its supporting structure into a lower air discharge chamber 17 and an upper filter chamber 18.

An open-topped, closed-bottom filter '19 which may be of suitable paper or fabric material is housed Within the filter chamber 18 and at its lower portion rests on the perforated shield and support member 13. The open end of the filter 19 is anchored to an annular channel member 20 as by means of the anchoring cords or wires 21. The member 20 is provided at its upper end with an outwardly directed horizontal flange 22 which is embedded in an annular rubber mounting gasket 23 resting upon the upper surface of the flange 2 to form an air seal therewith.

A dome-shaped cover 25 is provided for closing the upper end of the annular casing 1 and is hinged thereto to one side of the members 1 and 25 by means of a suitable hinge 26. The other side of the cover 25 is firmly secured to the casing 1 by means of a known type of snap acting latch mechanism indicated generally by the reference character 27.

An annular spring member 29 is mounted on the inside of the cover 25 and secured thereto by means of suitable rivets 30 which also serve to secure mounting brackets 31 for a handle 32 to the outer surface of the cover 25. The handle 32 is mounted on the brackets 31 by means of pivot rivets 33. The annular spring 29 is formed as a section of a cone as indicated in Figure 1 and terminates at the lower end in an outwardlydirected horizontal annular flange 34 which rests upon the upper surface of the gasket 23. The dimensions of the parts are such that the spring member 29, and in particular the flange 34 thereof, bears on the upper surface of the member 23 with the parts in the closed position illustrated in Figure l with sufficient'pressure to seat the gasket 23 firmly on flange 2 and to form an air seal between the gasket 23 and flanges 2 and 34. The bail handle 32 provides a means by which the cleaner structure may conveniently be carried from place to place and, as is apparent from Figures 1 and 2, it may be folded down against the upper surface of the cover 25 into an out-of-the-way position when desired.

The central portion of the cover 25 is provided with an inwardly-projecting tubular fitting 36 adapted to be connected to a suction hose in a manner to be described. The tubular fitting 36 is adapted to receive a bearing 'portion 37 on an elbow-shaped end 38 of a flexible suction hose 39. The hose 39 is adapted to be connected to a suitable dusting or cleaning tool 43. The bearing 37 on elbow fitting 38 is adapted to be detachably and pivotally secured in the tubular fitting 36 by means of spring-pressed projecting tab or finger 40 which is receivable in an annular groove 41 formed in the fitting 36. When it is desired to remove the elbow fitting 38 from the fitting 36, the finger 40 is withdrawable by finger pressure applied on the retracting button 42. The foregoing provides a readily detachable connection between the dusting tool hose and the cover 25 of the cleaner structure and in which the elbow fitting on the end of the hose is pivotally mounted in the cover of the cleaner structure so that the same may turn as the operator moves about in various angular relations to the cleaner structure.

It is apparent from Figure 1 that operation of the motor 8 drives the fans in the casing 7 which produce an air flow through the hose 39 and fitting 38 into the open interior of the filter 19 where dirt and dust are separated from the air stream which then passes through the perforated shield 13 and into the fan structure.

The lower side of the exhaust chamber or casing 17 of the housing 1 is closed by a downwardly-directed dome-shaped member 45 which is provided in its central portion with a fitting 46 adapted to receive the hose fitting 38 for the purpose of converting the cleaner to blowing operation should that be desired. The fitting 46 is normally open as illustrated in Figure l to permit exhaust air to discharge freely therethrough. The dome 45 is provided with a horizontally-directed peripheral flange 47 which rests against the underside of the flange 3 and is secured thereto in a manner to be described.

The cleaner structure so far described is supported by a cylindrical base frame 48 having a semi-circular section supporting bead 49 as its lower end adapted to rest upon a supporting surface and having a horizontallyextending, inwardly-directed flange 50 at its upper end engaging the under surface of the flange 47. The flanges 3, 47 and 50 are secured together in air-tight relation by means of spaced studs 51 which extend through the flanges 50 and 47 and thread into suitable tapped openings in the flange 3.

The lower end of the bead 49 extends below the lowest portion of the dome 45 so that only the bottom surface of the bead 49 actually engages the supporting surface upon which the cleaner rests. The lower end of the cylindrical base structure 48 is provided with a large central opening defined by the inner edge of a narrow, inwardly-projecting flange 52 to allow air discharging through the fitting 46 free access to the supporting surface.

Referring now to Fig. 2, the operation of my cleanersupporting device is illustrated when the cleaner is in use. In Figure 2 the cleaner is shown as being supported upon the surface of a floor covering such as a carpet 55. The air discharging through the fitting 46 is initially entrapped within the space between the dome 45, cylindrical supporting member 48 and that portion of the carpet or supporting surface 55 lying within the perimeter of the head 49. The base portion of the cleaner structure within and above the perimeter of the bead 49 comprises a comparatively large projected area subjected to the pressure of the air entrapped within the member 48 above the supporting surface. That space in effect forms a plenum chamber when the cleaner is in operation in which the pressure is above that of the outside atmosphere. The air pressure within the supporting ring 48 exerts suflicient force upon the cleaner structure to counterbalance the weight thereof and lift the cleaner slightly to allow the air to escape beneath the head 49 through the small opening 56 formed therebetween and the supporting carpet when the motor fan unit is operating and the nozzle is unsealed so that a significant air stream can flow through the cleaner structure and into the interior of the ring 48. Thus, in the use of the device the cleaner is not actually supported upon the bead 49 but upon an air cushion or hearing entrapped within the ring 48. This air cushion or hearing has been found to provide such support for the cleaner that a very slight force applied to the side thereof in a horizontal direction is suflicient to move the cleaner freely across a carpet; that is, in practice a very slight pull upon the hose 39 when the cleaner is in use is sufficient to cause the same to move large distances across the carpet with substantially no expenditure of energy on the part of the user.

That comes about by reason of the fact that the center of gravity of the cleaner is low and centrally located relative to the base 48 whereby a horizontal force applied to the casing will be less than sufficient to tip the cleaner about the bead 49 when the cleaner is partially or wholly air supported.

In the description so far, our invention has been described as applied to a device in which the air stream discharging from the motor fan unit into the interior of the supporting ring builds up suflicient pressure to counterbalance the weight of the cleaner and, in elfect, support the same on an air cushion or hearing. This type of support for the cleaner is effective only when the motor fan unit is operating and is highly desirable as the cleaner may be moved about with greatest of case without placing any significant strain on the op erator or on the hose 39 by which the. operator will normally manipulate the cleaner structure. In operation of a device such as described heretofore, the airlift imposes a slight additional back pressure on the machine as the air built up within the ring -33 depending upon the weight of the cleaner and the diameter of ring 48 and may be between one and two inches of water pressure higher than that which would be obtained if the fitting 46 discharged directly to the atmosphere, for example. This, however, is not a significant obstacle to the type of cleaner with which the invention is associated as such cleaners are now customarily provided with extremely large power plants, some approaching one horsepower in capacity, and are characterized by extremely large air flow. The suction produced by modern suction cleaners of this type is so great that many of them are provided with automatic forms of suction relief valves in the suction line to prevent too great suction pressures from building up which would make it substantially impossible to move the nozzle along a carpet or other heavy fabric with which it is engaged. The air which forms the supporting bearing or cushion is, of course, not a static body of air but is continually changing in identity as air is discharged through the fitting 46. The air within the ring 48 discharges in a large diameter thin annular stream underneath the bead 49.

Referring now to Figure 3, a modified form of our invention is disclosed. This form of the invention differs from that heretofore disclosed and described in detail only-in certain particulars respecting the supporting structu're and the manner in which an air float or air bearing is provided; hence, those portions of the apparatus of Figure 3 which are identical with corresponding portions of the apparatus of Figures 1 and 2 will be given the same reference characters as corresponding parts of Figures 1 and 2 distinguished by the addition of a prime. In the form of the invention illustrated in Figure 3 the main casing 1' is closed at its lower end by means of a dome-shaped end cover 6i) having a fitting 61 secured thereto but in off-center relation so as not to engage the downwardly-projecting portion of the motor 8'. The fitting 61, like the fitting d6, may be connected to the cleaner hose for converting the cleaner to blowing operation.

The supporting structure for this form of the invention comprises a cylindrical member 62 terminating in its lower end in a semi-circular surface-engaging bead 63 and open at its lower end except for that portion thereof closed by the member 63 and a narrow annular flange 64 projecting inwardly therefrom. The upper end of the annular member 62 is closed by a downwardlydished, dome-shaped member 65 which is complemental to and spaced from the dome-shaped member 60. The member 65 is provided with an opening 66 which is spaced from, but aligned with, the fitting 61 whereby exhaust air discharged through the member 61 may flow through the opening 66 into the interior of the supporting ring 62.

The supporting ring 62 is pivotally secured to the dome 6t) and in spaced relation thereto by means of a hinge 63 which has one leaf thereof secured to the member 6% and the other leaf thereof secured to the member 6% as illustrated most clearly in Figure 3. The opposed leaves of the hinge 6S and the rivets and studs 69 and 70 which secure these leaves to the

domes

60 and 65, respectively, serve as a spacing means for the

domes

66 and 65 on the sides thereof which are directly connected to the hinge structure. Those portions' of the dome-shaped

members

60 and 65 whichiare spatially removed from the hinge 68 are maintained spaced relation to each other by means of

outstruck protuberances

71 and 72, respectively, which are engaged with each other in the operative position of the parts shown in Figure 3. The parts of the apparatus constituting the supporting structure are maintained in a position illustrated in Figure 3 with respect to the casing 1 by means of a spring strap 73 secured to the casing 1 as by means of the rivets 74 and having an opening therein adapted to receive a pin 75 secured to the ring 62 and projecting outwardly therefrom. The spring member 73 is biased to move in a clockwise direction, as viewed in Figure 3, so that the same maintains itself in engagement with the pin 75. If his desired to obtain access to the fitting 61 to convert the apparatus to blowing operation, the spring 73 is first moved against its bias in a counterclockwise direction to disengage the same from the pin 75 after which the cleaner body may be pivoted in a counterclockwise direction, as viewed in Figure 3, away from the supporting ring 62 to expose the fitting 61 for converting operation.

In this form of the invention a portion of the air escapes into the space between the

domes

60 and 65 and then outwardly at the periphery of the cleaner as shown by the arrow in Figure 3. In the design of the cleaner the separation between the

domes

60 and 65 is so chosen with reference to the other constants of the particular machine that all or only a portion of the air normally discharged from the cleaning apparatus is allowed to escape in this manner. The construction illustrated in Figure 3 lends itself to a plurality of variants in design and function; that is, the change in function depends eutirely upon a choice of certain constants by the designer. For example, the space between the

domes

60 and 65 may be made very narrow so as to offer a very significant resistance to the air discharging therethrough. In this event, pressure built up in the plenum chamber within the ring 62 may be so chosen as to support all or only a portion of the total weight of the cleaning apparatus. At this point, it is necessary to consider another variable always present in the operation of cleaners of this type, mainly, the degree of seal obtained between the cleaning nozzle and the surface of the fabric undergoing cleaning. In normal usage, a partial seal is maintained between these parts which tends to offer considerable restriction to air fiow and to cut down the quantity of air flowing through the system below that which is obtained when the nozzle is held upwardly, for example, in air without contacting anything which might impede air flow therethrough. It is preferred to provide an apparatus of this type with a spacing between the

domes

60 and 65 which is insufficient to build up a complete lifting air pressure within the ring 62 when the cleaner is being used for normal cleaning; that is, the quantity of air discharged through the fitting 61 per unit of time is such that it can escape around the periphery of the cleaner through the space between the

members

60 and 65 continuously without building up pressure within the ring 62 sufiicient to counterbalance the entire weight of the cleaner in which event the ring 63 is always maintained in engagement with a supporting surface and air does not discharge beneath this member. If, however, the nozzle is disengaged from any body to be cleaned, the air flow is greatly increased and pressure builds up within the ring 62 sutficiently to overcome the weight of the cleaner onan air cushion or hearing and a portion of the air dis charges beneath the ring 63 in a manner described in the form of the invention illustrated in Figures 1 and 2.

Under conditions of free air flow through the cleaner in which it is supported on the air bearing, the slightest pull upon the hose is again suflicient t-ocaus'e the cleaner to tnove freely across the carpet "or other supporting stir face. Thus, this form of the invention rovides the eperator a positive control over the operation of the lifting device; that is, during normal cleaning when the nozzle or tool is engaged with a rug or carpeting or other fabric to be cleaned, the air flow is so cut down that all air discharged by the cleaner discharges between the members and in a diffused ring directed at a slight upward angle and spaced sufiiciently far above the supporting surface so as not to tend to blow or scatter dust or litter which .may be freely resting on the surface thereof, whereas, when the operator desires to move the cleaner body she has only to manipulate the nozzle 43' to provide free air flow thereinto in which event the cleaner then becomes air supported and a slight tug on the hose is sufiicient to move the same wherever the operator may desire. With this arrangement, air discharges from beneath the ring 63 only when the nozzle is free and the operator has positive control over the air lift or air bearing feature of the cleaner support structure.

It is within the purview of our invention to increase the size of the spacing between the

members

60 and 65, relatively to the constants of the particular machine, to a value such that under free air flow conditions the air pressure within the ring 62 will support only approximately 90% of the total weight of the cleaner in which event air will always discharge through the space between

domes

60 and 65, there will never be a lateral blowing of air across the supporting surface under the ring 63 and the cleaner may be moved easily because the pressure with which it bears on the supporting surface is comparatively light. A suction cleaner designed in accordance with the foregoing is not as easily moved as one in which the entire weight of the cleaner is counterbalanced by the air column or cushion produced by the discharge, but air never discharges along the supporting surface. In

each instance, when the cleaner is in operation, a plenum chamber is formed within the ring 62 in which the pressure is above atmospheric pressure a sufficient amount to support all or a portion of the weight of the cleaner.

Referring now to Figures 4 and 5, our invention is illustrated as being applied to a different type of suction cleaner. In this form of the invention the type of air bearing or air support illustrated in connection with Figures 1 and 2 is utilized.

In the devices of Figures 4 and S, we have illustrated a conventional so-called tank type suction cleaner having our invention applied thereto.

The cleaner proper comprises an outer casing having a substantially fiat or plane bottom wall 81. A motor fan power plant unit 82, which may be substantially identical to that of the power plant structure 6 of Figure 1, is mounted Within the casing 80, being supported at its forward or air inlet end in a gasket 83 which is carried by a bulkhead 84 secured to the interior wall of the casing 80. The rear end of the power plant 82 is supported in a gasket 85 which is carried by a second bulkhead 86. The rear end of the casing 80 is closed by an imperforate cover plate 87.

A filter 88 which may be of fabric or paper or a compound filter such as are commonly used in this type cleaner is mounted within the casing 80 forwardly or to the right of the power plant unit as viewed in Figure 4. The front end of the cleaner is closed by a cover 90 hinged as indicated in 91 to the casing 80 and secured in a closed position by means of a suitable latch 92 of known type. The cover 9% is formed in a known manner releasably to receive the connecting end 94 of a flexible hose 95 which communicates at its end with a suitable dusting tool 96.

When the device is in operation, the motor fan unit 82 creates a suction by drawing air from the portion of the casing 80 housing the filter. This causes air to flow through the tool 96, hose 95, fitting 94, into the interior of the filter structure 88 and therethrough into the suction-producing unit which discharges into the interior of the casing 80 to the left of the bulkhead 84 as viewed in Figure 4. Air so discharged by the motor fan unit serves to cool the motor and then flows through the exhaust fitting 98 to the underside of the cleaner body 80 where it is entrapped Within the confines of an air bearing or air cushion forming device to be described.

In the particular form of tank cleaner herein illustrated, the bottom wall 81 thereof is shown and described as being plane or flat but this, however, is not a necessary construction in order to utilize and enjoy the advantages of our invention; it is chosen for convenience of illustration.

The underside wall 81 of the casing 80 is provided with a supporting bead member 100 which extends from the rear or left-hand end of the casing as viewed in Figure 5 forwardly on adjacent opposite sides thereof toward the front end of the cleaner where the two sides of the member 100 curve inwardly and join in a roughly V-shaped apex 1431. At the rear of the cleaner the bead lot} extends across the width thereof to join the two side legs, thus forming an enclosure or plenum chamber extending around the discharge fitting 98. As a consequence of the foregoing construction, exhaust air discharging through fitting 98 is entrapped within the confines of the annular supporting bead 100 and exerts an upward pressure on the body of the cleaner suflicient to overcome or counterbalance the weight thereof to lift the cleaner a small degree to permit air to escape under the edge of the bead or supporting skid 100 in the manner in which air escapes under the member 49 as illustrated in Figure 2.

In this form of the invention the hose connector 94 is straight as contrasted with the elbow-shaped connector 33 disclosed in connection with Figure 1. That is for the reason that this type of cleaner lies low to the floor and is so arranged that the hose leaves the end thereof angled upwardly at a slight angle to the supporting surface. If the operator wishes to turn the cleaner, a slight tug on the hose will accomplish this purpose as well as draw the cleaner towards her because of the free support of the cleaner body upon an air cushion or air hearing.

In this form of the invention, the cleaner is turned over on its side or optionally set upright on the end cover 87 and the hose 94 is secured in the fitting 98 when it is desired to convert the same to blowingoperation. v

In each of the forms of the invention specifically illustrated herein, an annular supporting skid has been provided on the cleaner which skid encloses a substantial area on the underside of the cleaner and into which air under pressure is discharged for the purpose of providing an air bearing or air cushion support for the cleaner in use. An annular skid as above described is a preferred supporting structure as it provides for minimum resistance to movement of the cleaner when the air pump is not operating; however, the surface engaging portions of our apparatus may be, if desired, in the form of a plane body having a substantial area connected by means of a conduit to the discharge side of the air pump whereby air under pressure discharges beneath the plane area and flows between it and the supporting surface to form the air cushion or bearing.

In accordance with our invention, all forms thereof provide means by which the exhaust air from the cleaner in use is entrapped within or under a supporting surface or skid having an area sufiicient to cause the pressure of the entrapped exhaust air to counterbalance all or a major part of the weight of the cleaner and then to escape in a narrow diffused stream around the periphery of the supporting means.

It is characteristic of our invention that the cleaner is wholly or partially supported on an air cushion or air bearing confined between the cleaner body and supporting surface by an annular support or skid and has a substantially frictionless relation to the supporting surface whereby a very slight force applied thereto in any direction substantially normal to the supporting surface against eye -see '9 which -the air bearing is pressing will cause the cleaner to move freely.

While we have illustrated and described the invention in considerable detail, it is to be understood that various changes may be made in the arrangement, proportion and construction of parts without departing from the spirit of he invention or the scope of the appended claims.

We claim:

1. In a suction cleaner comprising a casing, a suction cleaning nozzle connected by a flexible hose to the casing, an air pump in the casing connected to the hose to produce a flow of cleaning air into the nozzle through the hose to the air pump and a drive motor for the air pump in the casing, the combination of an annular skid for supporting the cleaner in a stable position on a supporting surface and normally bearing on the supporting surface and enclosing an air space beneath the cleaner casing having a substantial projected area below the casing and exposed to the supporting surface, and means for leading air discharged by the air pump to said air space, said skid being formed to restrict the flow of air from said air space, the area of said air space which is exposed to the supporting surface being so related to the weight of the cleaner and to the quantity of air discharged into said air space that an air cushion is built up within said air space under sufficient pressure to support the major part of the weight of the cleaner on said air cushion, the center of gravity of the cleaner being so related to the area of said air space exposed to the supporting surface, and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported on said air cushion that the cleaner may be propelled about, in a stable condition, by the application of the necessary horizontal force to the cleaner.

2. A suction cleaner according to claim 1 wherein the means for leading air under pressure to the air space comprises a fitting adapted to be connected to a flexible hose for converting the cleaner to blowing operation.

3. A suction cleaner according to claim 1 wherein the annular skid is attached to and projects below a wall member, the casing is hingedly connected to the skid and wall member, the casing includes a base member spaced from the wall member, means are provided for maintaining the base member and wall member in predetermined spaced relation providing a restricted orifice at the periphery of the wall member, and means are provided for conducting air under pressure from the air pump to the space between the wall and base member and to the space below the wall member.

4. A suction cleaner according to claim 3 wherein the air conducting means includes a fitting opening through the base member to the space between the wall and base members exposable for attachment of a flexible hose thereto by pivoting the casing away from the wall member and skid.

5. In a suction cleaner having a casing including an air inlet port and an outlet port, means for connecting a suction cleaning nozzle to the air inlet port by means of a flexible hose, means in the casing for producing a flow of cleaning air from the nozzle into the casing and for discharging such air under pressure from the out-let port, the combination of a means for supporting the cleaner in a stable position on a supporting surface and for entrapping air under pressure discharging from the outlet port and forming an air cushion between the casing and the supporting surface, said supporting means being formed to restrict the flow of air :between the casing and the supporting surface, the area of said air cushion in contact with the supporting surface being so related to the weight of the cleaner and to the quantity of air discharged from said outlet port that the {pressure of the entrapped air serves to support the major part 'of the weight of the cleaner, the center of gravity of the cleaner being so related to the area of said air cushion 10 and to the horizontal force necessary to propel thecleanei along the supporting surface when the cleaner is supported on said air cushion that the cleaner may be propelled about, in a stable condition, by the application of the necessary horizontal force to the cleaner.

6. in a suction cleaner having a casing including an air inlet port and an outlet port, means in the easingfor producing a flow of cleaning air into the casing and for discharging such air under pressure from the outlet port, the combination of a supporting structure attached to the having a surface engaging part forming a peripheral wall for supporting the cleaner in a stable position on supporting surface and defining an open bottom plenum chamber between the casing and the supporting surface, said chamber being arranged to receive air under pressure from the outlet port and entrapping the air therein to form an air cushion, said surface engaging part being formed to restrict the flow of air from said chamber, the area of the open bottom of said chamber "being so related to the weight of the cleaner and to the quantity of air received from said outlet port that the air pressure in the chamber supports the major part of the weight of the cleaner, the center of gravity of the cleaner being so related to the area of said open bottom plenum chamber and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported on said air cushion that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal 'force to the cleaner.

7. in a suction cleaner having a casing, an air pump in the casing connected to produce a how of cleaning air into the casing and to place such air under pressure, the combination of a supporting structure for supporting the cleaner in a stable position on a supporting surface and including a surface engaging part having a perimeter enclosing a space on the underside of the casing open to the supporting surface and means for discharging air placed under pressure by the air pump into said space, said surface engaging part being formed to restrict the flow of air from said space, the extent of said space open to the supporting surface being so related to the weight of the cleaner and to the quantity of air discharged beneath said surface engaging part that a cushion of air is formed within its perimeter under sufiicient pressure to support the major portion of the weight of the cleaner, the center of gravity of the cleaner being so related to the area of said supporting structure and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported on said air cushion that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal force to the cleaner.

8. A suction cleaner according to claim 7 wherein all the air placed under pressure by the pump is directed into the said space and the air escapes to the atmosphere by flowing under said surface engaging part.

9. A suction cleaner according to claim 7 wherein the apparatus includes restricted air exhaust ports for e:-:-. hausting air under pressure to the atmosphere while maintaining a predetermined air pressure in the said enclosed space.

10. in a suction cleaner having "a casing, a suction cleaning no'zzle connected to said casing by means of a flexible hose and a suction air pump in the casing connected to induce a flow of cleaning air into the nozzle and thence to the pump, the combination or supporting means on the casing including an annular peripheral por: tion for supporting the cleaner in a stable position on a supporting surface anddefining the outer perimeter of an air space on the underside of the casing and open to the supporting surface over a substantial area within said annular portion and means for supplying air under pressure from the air pump to the said air space, said annular peripheral portion being formed to restrict the new of air from said air space, the ateaof the "supporting surface encompassed by said annular peripheral portion being so related to the weight of the cleaner and to the quantity of air supplied to said air space that a cushion of air is formed within said space suflicient to form a weight supporting air cushion beneath the casing under sufiicient pressure to carry the major part of the weight of the cleaner, the center of gravity of the cleaner being so related to the area of the supporting surface encompassed by said annular peripheral portion and to the horizontal force necessary to propel the cleaner along the supporting :surface when the cleaner is supported on said air cushion that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal force to the cleaner.

ll. A suction cleaner according to claim l wherein all the air discharged by the air pump is supplied to said space and builds up a pressure sufiicient to support the weight of the cleaner before escaping under the said annular portion.

12. A suction cleaner according to claim wherein the casing includes an auxiliary exhaust port above the lower portion of the supporting means and the exhaust port is so restricted as to maintain a supporting air pressure in the said space sufiicient to carry the major part of the weight of the cleaner.

l3. A suction cleaner according to claim 10 wherein the casing includes an auxiliary air exhaust port above the lower portion of the supporting means, and the exhaust port is so restricted that all air discharged from the air pump is exhausted through the port when the nozzle is restricted and a part of the air discharged from the air pump exhausts between the supporting surface and the annular portion of the supporting structure when the nozzle is unobstructed.

14. In a suction cleaner a casing, a filter in said casing, and a motor driven air pump in said casing for drawing cleaning air into the filter to the pump, the combination of an annular supporting skid depending below the casing and adapted to engage a supporting surface for supporting the cleaner in a stable position thereon, said skid forming a base skirt at the bottom of the cleaner and being open at its bottom, and means for conducting air under pressure discharged fromthe air pump into the space within the skid, said skid being formed to restrict the flow of air beneath said base skirt, the area of the space of the supporting surface within said skid being so related to the weight of the cleaner and to the quantity of air conducted into it that a cushion of air is entrapped within it under suflicient pressure to support the cleaner on a cushion of air, the center of gravity of the cleaner being so related to the area of the supporting surface within said skid and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported on said air cushion that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal force to the cleaner.

15. In a suction cleaner having a casing including an air inlet port and an outlet port, means in said casing for producing the flow of cleaning air from said inlet port into said casing and for discharging such air under pressure from said outlet port, the combination of means for entrapping air under pressure discharging from said outlet port and forming an air cushion between said casing and a supporting surface and forming a support for supporting the cleaner in a stable position on a supporting surface, said means being formed to restrict the flow of air between said casing and the supporting surface, the area of contact between said air cushion and the supporting surface being so related to the weight of the cleaner and to the quantity of air discharged into said air cushion forming means from said outlet port that the pressure of the entrapped air normally serves to support the major part of the weight of the cleaner, means responsive to an increase in the flow of air through said outlet port for increasing the pressure of the entrapped air sufiieiently to carry the entire weight of the cleaner, the center of gravity of the cleaner being so related to the area of contact between said air cushion and the supporting surface and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported on said air cushion that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal force to the cleaner.

16. In a suction cleaner according to claim 15 including a suction nozzle attached to said hose, the arrangement being such that the pressure of the entrapped air will be insufiicient to raise the weight of the cleaner so long as said nozzle is applied to the surface being cleaned and will be sufficient to support the cleaner when said nozzle is removed from the surface being cleaned to provide a free flow of air through the cleaner.

17. A suction cleaner comprising, a casing, said casing having an inlet port and an outlet port, a fan unit within said casing for drawing air into said casing through said inlet port and for discharging it through said outlet port, a filter positioned within said casing between said inlet and outlet ports in the path of air flow produced by said fan unit, a support for said casing for supporting the cleaner in a stable position on a supporting surface, said support including an annular surface engaging member forming a pocket between the base of said casing and the supporting surface upon which the cleaner rests and encompassing a substantial area of the supporting surface, said exhaust port communicating with said pocket so as to build up an air pressure therein, said annular surface engaging member being formed to restrict the flow of air from said pocket, the area of the supporting surface encompassed by said annular surface engaging member being so related to the weight of the cleaner and to the quantity of air discharged into said pocket that the air pressure built up therein is sufiicient to carry the major portion of the weight of the cleaner, means responsive to an increase in air flow through the cleaner for increasing the air pressure formed within said pocket so that it is sufiicient to carry the weight of the cleaner, the center of gravity of the cleaner being so related to the area of the supporting surface encompassed by said annular surface engaging member and to the horizontal force necessary to propel the cleaner along the supporting surface, when the cleaner is supported by said air pressure that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal force to the cleaner.

18. A suction cleaner according to claim 17 including a suction nozzle, the arrangement being such that the pressure within said pocket will rise sufiiciently to support the cleaner on an air cushion when said nozzle is raised from a surface being cleaned to provide for the free flow of air through said casing and the air pressure within said pocket will be reduced when said nozzle is applied to a surface to be cleaned to a point where the pressure within said pocket will be insufficient to support the entire weight of the cleaner.

19. A suction cleaner comprising a casing, said casing having an inlet port and an outlet port, a fan unit within said casing for drawing air into said casing through said inlet port and for discharging it through said outlet port, a filter positioned within said casing between said inlet and outlet ports in the path of air flow produced by said fan unit, a support for said casing for supporting the cleaner in a stable position on a supporting surface, said support including an annular surface engaging member forming a pocket between the base of said casing and the supporting surface upon which the cleaner rests and normally encompassing a substantial area of the supporting surface, said exhaust port communicating with said pocket so as to build up an air pressure therein, said annular surface engaging member being formed to restrict the flow of air from said pocket, the area of the supporting surface encompassed by said annular surface engaging member being so related to the weight of the cleaner and to the quantity of air led into said pocket that the air pressure built up therein is sutficient to carry the major portion of the weight of the cleaner, means for varying the air pressure produced within said pocket whereby it may be increased to a point sufiicient to carry the weight of the cleaner and reduced to a point which is insufficient to carry the weight of the cleaner, the center of gravity of the cleaner being so related to the area of the supporting surface encompassed by said annular surface engaging member and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported by said air pressure that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal force to the cleaner.

20. A suction cleaner according to claim 19 including a suction nozzle and in which said last mentioned means includes an air vent between said pocket and atmosphere above said annular surface engaging member, the arrangement being such that the pressure within said pocket will increase sufliciently to carry the weight of the cleaner when said nozzle is raised from a surface being cleaned and will decrease when said nozzle is applied to a surface being cleaned so as to be insuflicient to support the entire weight of the cleaner.

21. In a suction cleaner, a casing having a hose connecting fitting thereon, a flexible suction hose including a cleaning nozzle connected to said fitting, a filter in the casing, and a motor driven air pump in the casing for drawing cleaning air into the nozzle and through the hose and filter to the pump, the combination of an annular support depending below the casing and adapted to engage a supporting surface, said support including a base skirt forming an open bottom space at the base of the cleaner and encompassing a substantial area of the supporting surface, and means for conducting air under pressure discharged from the air pump into the space within the support wherein the air is entrapped therein, said casing being formed to restrict the flow of air from the space within said skirt, the area of the supporting surface en compassed by said skirt being so related to the weight of the cleaner and to the quantity of air conducted to said space that an air pressure is built up within said space sufiicient to carry the major portion of the weight of the cleaner and means between said support and easing above the lower edge of said support forming a vent to place said space in communication with the outside of said casing whereby air under pressure normally flows through said vent to the air outside of said casing, the center of gravity of the cleaner being so related to the area of the supporting surface encompassed by said skirt and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported by said air pressure that the cleaner may be propelled about by the application of the necessary horizontal force to the cleaner.

22. In a suction cleaner having a casing including an air inlet port and an air outlet port, and means in said casing for producing a flow of air into said inlet port and for discharging air under pressure from said outlet port,

said casing having a supporting base normally supporting the cleaner in a stable position on a supporting surface when said air flow producing means is not in operation, said base including a downwardly facing portion adapted to coaet with a supporting surface to encompass a substantial area thereof and to restrict the flow of air from the encompassed area between said portion and the supporting surface, said outlet port being arranged to discharge air under pressure beneath said base within the confines of said downwardly facing portion, the area of the supporting surface encompassed by said downwardly facing portion being so related to the weight of the cleaner and to the quantity of air discharged beneath said base that the air under pressure reacts between said casing and the supporting surface to form a supporting cushion of air which serves to support the major part of the weight of the cleaner, the center of gravity of the cleaner being so related to the area of said base and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported on said air cushion that the cleaner may be propelled about in a stable con dition by the application of the necessary horizontal force to the cleaner.

23. In a suction cleaner including a casing having an inlet port, suction creating means within said casing, said casing having a supporting base adapted to encompass a substantial area of the supporting surface upon which the cleaner rests to support the cleaner in a stable position, at least the periphery of said base being normally in contact with the supporting surface when the cleaner is not in use and means for supplying air under pressure beneath said base, said casing being formed to restrict the flow of air from beneath said base, the area of the supporting surface encompassed by said base being so related to the weight of the cleaner and to the quantity of air supplied beneath said base that the air under pressure reacts between said base and the area of the supporting surface encompassed by said base to form a supporting cushion of air which serves to support the major part of the weight of the cleaner, the center of gravity of the cleaner being so related to the area of the supporting surface encompassed by said base and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported on said air cushion that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal force to the cleaner.

References Cited in the file of this patent UNITED STATES PATENTS 1,083,408 Matchette Jan. 6, 1914 1,247,654 Farnsworth Nov. 27, 1917 2,037,557 Ahnstrom Apr. 14, 1936 2,287,474 Hansson June 23, 1942 2,332,208 Dow Oct. 19, 1943 2,719,600 Brace Oct. 4, 1955 FOREIGN PATENTS 571,465 France May 17, 1924