US2244165A - Suction cleaner - Google Patents

Description

Julie 3, 194 c. H. M FARLAND ETAL 2,244,165

' SUCTION CLEANER Filed May 25, 1939 2 Sheets-Sheet l a k r INVENTOR Llzarles [i MacFarland A 8+ Howard A. Shumalrer ATTORN EY June 1941, 0 c. H. M' FARLAND ET AL 22 sucwzou CLEANER I Filed Ma 25, 1939 2 Sheets-Sheet 2 INVENTOR Charles l2. MacFarland a! fi oward A. Jhumalrer ATTORN EY .wherever dirt is removed longitudinally thereof and Patented June 3, 1941 UNITED STATES 'PATENT- OFFICE t r 2,244,165

The Hoover Compan corporation of Ohio MacFarland, rrimos, Pa.,

North Canton. Ohio,

and Howard minors to 7, North Canton, Ohio, a

Application May 25, 1939, Serial No. 275,620

a claim. (on. 183-63) This invention relates to improvements in suction cleaners and more particularly to a dirtseparating system for suction cleanerswherein the separation is performed by a separating or filter member rotating at high speed within a chamber located between the nozzle and the fan chamber.

stream before it is carried by suction into the fan chamber and as a result clean air is discharged from the fan chamber into the atmosphere. It may be added that a cleaner of this general design is sometimes referred to as a bagless cleaner with the rotating filter member taking the piece of the usual filter bag.

The merit 'ci a rotary separating and filter member lies in the fact that advantage can be taken of centrifugal force in removing the bulk of the dirt from the air by impact with its surface and also in keeping the filter relatively free from clogging, so that the cleaner can be operated for relatively long periods of time without cleaning the filter.

However, there is one problem that exists by a rotary filter member and that is in providing an effective seal against the passage of dirt-laden air through the clearance spaces which must necessarily separate the rotating parts from the surrounding chamber walls. Otherwise, the escape of any considerable quantity of dust into the atmosphere of the room in which the cleaner is being operated, would be detrimental to its success as a bagless" cleaner.

Therefore, the object of the present invention is to provide for the effective and positive sealing of the rotary separating member and associated running parts against the escape or bypassing of dirt-laden air into the fan chamber and thence to the atmosphere.

A preferred embodiment of the invention is disclosed in the accompanying drawings in which:

Figure 1 is a general view of a cleaner of a rotary filter type, shown in vertical section taken showing the general arrangement of parts;

Figure 2 is a grouping of perspective views of the various parts of the cleaner associated with the air handling and sealing, these parts being disassembled and spaced apart so as to show their construction more clearly;

Figure 3 is a view in vertical section taken through the fan chamber as on line 3-3 of Fi ure 1; and

By this arrangement, the dirt is removed from the air Figure 4 is a view of the cleaner in front elevation. I a

The suction cleaner embodying the present invention is preferably of the horizontal motor type, with the motor, fan and dirt-separating member arranged in that order from rear to front.

As clearly shown in Figure ,l,"the body-of the cleaner consists of a main housing or casing 1 within which are located the motor 2, the motordriven fan 3v and filter member I,

armature shaft. The main easing l is divided into several parts or sectons, namely, a somewhat elongated cylindrical mot r casing 6 a fan chamher I relatively narrow in depth and of increased diameter, and finally, a separator chamber 8, including a nozzle 9 extending transversely across the forward end of the cleaner and having a downwardly opening suction mouth. The separating member 4 of frustro-conical shape is fixed at theJorward end of the shaft 5, with its apex directly in 8 to the large chamber forming a collecting receptacle for the dirt removed from the air stream by the filter.

The cleaner is preferably constructed with the several sections assembled end to end in the manner suggested in Figure 2; although for the purpose of the present disclosure, the main casing I may be regarded as of a unitary construction, except for the section 8 housing the separator member which must be detachable for emptying the dirt accumulating in the bottom of the chamber. For this reason, the front section 8 is held in place by means of a pair of clampingbolts II, "I, one on each side of the casing section and adapted to engage a pair of ears H, II formed integral with the section 8 just behind, as clearly shown in Figure 4.

To complete the general assembly, the cleaner body is supported'on pairs of front and rear wheels l2, l2 and l3, l3, respectively, and furthermore, carries a handle I! shown in part as an inverted U-shaped bail which straddles the main casing and has pivotal connection therewith so that the handle can swing forwardly and rearwardly with the reciprocating movement of the cleaner body over the carpet surface.

Referring now more in detail to the fan and rotary separator assembly, it is to be noted that a transverse partition or dividing wall l5 separates the fan chamber from the separator chamcenter where a relatively large 15a is formed in the. dividing ber, except at its annular opening the latter being mounted upon an extension 5 of the motor the discharge outlet from the nozzle 7 wall concentrically with the axis of ,rotation of the is! most part, the fan 3 is of a-design moreiorlws standard for suction cleaner use and consisting of a hui'slportion ta'having fixed hearing on the shaft 5, a radial disc lb integral with the hub and providing a backing plate for the radial vanes or blades 3c and finally, a fiat ring or shroud l 6 formed integral with the outer front edge portions of the blades 30 and including an annular flange l6a. slightly less in diameter than The skeleton frame also includes a ring-shaped base plate or shroud I! having an internal flanged portion I la adapted to have threaded engagement with the forward end of the annular flange lGw.. iritegral with the shroud l6 of the fan 3. In this way. the fan 3 and the separator member cannot only mounted upon the same shaft but are also joined together through their respective parallel shrouds l6 and I! on opposite sides of the partition wall Ii with the connecting annular flange .i-ic forming the passage from the separator ch mber to the fan chamber.

NOmassuming-that all of the air entering through the nozzle is drawn through the filter member and thence into the fan chamber, and that the filter screen is 100% efficient in its ability to remove the dirt from the air stream, it follows that the air han'dled by the fan would be entirely free of dirt and hence fit to be discharged directly into the room. But as previously stated, there must be some clearance between the rotating separating or filter member and the chamber walls in which the inlet opening to the fan chamber is located, and to prevent the passage of dirt-laden air around the filter member and into the fan chamber, is a matter of reducing the pressure differential in the clearance space in a degree such that a counterfiow of air is created to oppose the natural flow of air from the region of higher to lower pressure.

Referring now to the sealing arrangement; attention is first directed to the transverse rear wall l8 of the fan chamber carrying one of the main bearings l9 for'the armature shaft 5. As

shown in Figure 2, this wall i8,-having the form oi a circular plate, is eccentric with respect to the fan {having its geometric center ofi'set directly below the fan axis), and, being considerably largeiin diameter than the fan, defines the periphery of an eccentric air-space surrounding the fan, the radial depth'of which even at its narrowest point is considerably greater than is no required for a fan chamber. As a matter of fact, the annular outer and front walls of the fan chamber are formed by a separate and secondary wall segment 20 which is fitted into the main fan chamber section 1. This internal section 2| has a somewhat irregular shape but-generally dishshaped, with a large circular opening 20a in its front wall.

As clearly shown in Figures 1 and 3, this internal'fan chamber section 20 is supported eccentrically within the outer section I, with its front located in the rear wall wall spaced a short distance from the partition wall l5 and its annular opening 20a registering with the central opening lSa therein. Moreover, the outer annular wallportion 20b of the section 20 has. edgewise sealing contact with the face ofithe transverse partition wall l8 and follows the usual helix or volute around the periphery of the fan with the ofiset ed by a radially disposed segment 20c at apoint immediately below the fan where it registers with a discharge port 2| from the fan chamber l8. An auxiliary housing 22 attached to the underside of the motor casing i is preferably added as the air stream by exhausting it through series of upwardly directed louvres 22a in the sides of the housing. Thus, the air entering the fan chamber at the center or eye of the fanfrom the separator chamber follows the usual path inannular opening 20a in the forward vertical wall thereof clears the collar Ilia, joining the fan with the filter member, leaving a space leading directly back to the fan chamber with a relatively narrow clearance between the fan shroud l6 and the inner face of the front wall of the fan chamber. Again, it is to be noted that the annular and eccentrically formed air space immediately surrounding the actual'fan chamber c0mmuni-,

cates with the narrow space between the front wall of the fan chamber and the partition wall Ii, which in turn communicates with the clearance space between the front face of the partition wall l5 and-the filter member 4. Thus, if atmospheric air is admitted to this air space, it will flow radially inward along the passage between the fan chamber and the partition wall I5 and thence, making a U-turn, will fiow radially outward into the separator chamber after the manner indicated by the arrows in Figure 1.

But to insure this counterfiow of air, it is vital to prevent the flow of air between the front shroud ii of the fan and the adjacent wall of the fan chamber as would otherwise take place, due to the considerably greater atmospheric pressure existing in the region surrounding the fan. Hence, to seal this clearance space against the passage of air. a so-called labyrinth" seal is provided between the fan shroud l6 and the adjacent wall of the fanchamber, thisseal consisting of a series of interfitting annular grooves and ribs, as at 23, which act to retard the passage of air at this point. Now, with the fan chamber sealed against the counterfiow of high pressure air toward the filter chamber by the presence of the labyrinth seal at 23, and the pressure within the separator chamber at less than atmospheric pressure under normal operating conditions, a constant flow of air at atmospheric pressure from the air space wfll be maintained through the clearance space between the partition wall l5 and the shroud ll of the filter member, the direction of this counterflow directly opposing the flow of fan chamber and thence into the atmosphere.

Under normal operating conditions-with a constant pressure difl'erential between the filter wall segments unit-.

a means of breaking up blades and thence laden air around the filter, memben.

aeunoo i 4115;.-

chamber and the fan chamber, this counterflow of atmospheric airis calculated to provide an efiective .seal against the by-passing of dirt- However. should the cleaner be operated in such a manner as to break or materially reduce the sealing contact between the nozzle and the carpet. there would be a sudden decrease in suction at the nozzle and a consequnt approach to atmospheric pressure in the filter chamber, which wouldvery likely cause a pull of dirt-laden air to be discharged into the room each time the nozzle was lifted from the carpet or thecleaner Now, toprevent this reversal of air fiow in the sealing passages, due to temporary and sudden variations in the pressure differential between the atmosphere and the separator chamber, a positive counterflow is insured in part by providing what may be termed a booster fan,

consisting of a plurality of fan blades 24 mounted on the rear face of the shroud H at the base portion of thefilter member 4. Obviously, with these booster fan bladesv 24 the shroud ll becomes a fan acting to maintain a positive fiow of air which will not be afiected by sudden variations in pressure within the dirt separating system.

And finally, there is the matter oi conducting the atmospheric air into the air space surrounding the fan chamber and, as already pointed out, any connection from this air space to the atmosphere would be quite satisfactory. Notwithstanding, a novel feature of the present disclosure is the utilization of the atmospheric air for cooling the motor before it is led into the air space and thencethrough the sealing passages.

Referring to Figure 1, it will be noted that inlet ports 25 are provided at the rearmost end of the motor casing 6 and preferably on the underside thereof, the arrows indicating the direction of air flow through these ports, thence in a forward direction through and around the arma- -ture and field coils, this circulation of the motor ventilating air being induced and maintained by an auxiliary ventilating fan 28 mounted on the armature shaft between the armature and the adjacent.partition wall l8.

The auxiliary or ventilating fan 26 is preferably closed within its own fan chamber by introducing a partition wall 21 into the motor casing just to the rear of the fan, a central aperture in the plate forming the eye or inlet opening 21a to the ventilating fan chamber. The outlet passage from the ventilating fan chamber is at its top and connects with a substantially oval-shaped port 28 leading into the upper end of the air space surrounding the tan chamber. Thus, the same air which cools or ventilates the motor is utilized for creating and maintaining the so-called counterfiow air-seal for the clearance spaces between the chamber walls and the rotary filter member, the tan, or both.

' The advantages of the air-seal in a cleaner using a rotary dirt-separating system include the absence of contact between running parts' and the consequent wear and frictional losses, as well as the ability to maintain an eflectiveseal that is not dependent upon the exact dimensioning of parts or accuracy in fitting certain parts together. In fact, the maintenance of an through a passage leading to the clearance space effective seal requires only that an adequate pressure differential be maintained at all times.

It should be observed, however; thatatmos- I pheric air can be led directly into the sealing passages and therefore the present invention is not limited to the circulation of air through the motor for cooling purposes and hence into the system of sealing es, nor to any particular arrangement for maintaining a positive unirorm air -fiow type of dirt-separating member.

Having set forth a preferred embodiment of the invention, we claim: V

1. In a dirt-separating system, the combination 01 a rotary dirt-separating member mount ed within a chamber having an inlet and an outlet, and means for sealing against the leak-' age of dirt-laden air around said separating member and through said outlet opening including means for iorcing air from an external source between said separating member and the surface 0!; said chamber adjacent its outlet.

2. .In a dirt-separating system, the combina tion of a rotary dirt-separating member mounted within a chamber having an inlet for the dirt-laden air and an annular opening in one of its walls concentric'with the axis of rotation of said dirt-separating member, the lat-v. ter having an annular flanged portion registering with the opening in said chamber wall, and means for sealing the clearance space between the said annular flanged portion of said dirt separating member and the said opening in the chamber wall. comprising a passage formed between said chamber wall and a complementary wall spaced therefrom. and means for forcing; air into said clearance space in a direction counand forming an auxiliary air passage leading to 7 said clearance space, and means for a constant counterfiow of air through; said, air

passage and clearance space while the system i in operation.

4. In a dirt-separating system, the combination oi a rotary filter member mounted within a chamber having an inlet opening for the dirtladen air. said filter member having an annular base portion and a centrally locatedflanged opening therein with an annular opening in the adjacent .wall in said chamber, and means for sealing 'the clearance space between the baseot said filter member and said adjacent wall, oomprisingan' auxiliary wall segment spaced from said adjacent wall oi the filter I chamber and forming a disposed air passage leading to said clearancaspace rum the atmosphere, and means for forcing airfih iwh said I 5.121 a dirt-separating system, the combinetion of a filter chamber having. an inlet opening for the dirt-laden air, a rotary filter member mounted in said chamber and having an annular base portion with a flanged opening at its center registering with a concentric opening in the adjacent wall or said chamber with a clearance space therebetwcen, and means for sealing said clearance space against the leakage of dirtladen air including a wall segment spacedirom the adjacent chamber wall and forming a radially disposed air passageleading to said clearance space and communicating with the atmosphere, and a motor-driven auxiliary fan for maintaining a constant counterflow of air through said passage.

6. In a dirt-separating system. the combination of a rotary filter member mounted within a chamber having an inlet for the dirt-laden air, said filter member consisting of a conicalshaped screen having an annular base with a centrally located flanged outlet registering with a concentric opening in the adjacent wall of the chamber, and means for sealing the Tclearance space between said filter member and the adjacent chamber wall, comprising an exterior wall segment spaced from said adjacent chamber wall and forming an air passage therebetween leading from the atmosphere to said clearance space, and means for maintaining a constant counterfiow of air to said air passage including a group of radially disposed impeller blades mounted on the face of the base of said filter member and surrounding said flanged outlet.

7. In a dirt-separating system, the combination of a filter chamber having an outlet vfor the dirt-laden air, a fan chamber separated from said filter chamber by spaced walls forming an air space therebetween and having a connecting opening therein, a motor-driven filter and fan mounted in said filter and tan chambers respectively, said filter having an annular flanged outlet passage registering with the opening from said filter chamber to said fan chamber with the of air to said air space from a source exterior said filter chamber.

8. In a dirt-separating system, the combination of a rotary dirt-separating member mounted within a chamber having an inlet opening for the dirt-laden air and an outlet opening for the filtered air arranged concentrically with respect to the axis of said dirt-separating member, the latter comprising an annular base portion registering with said outlet opening with a clearance space therebetween, an external wall spaced from the chamber wall in which said outlet opening is located and forming. a passage communicating with said clearance space exterior-of said chamber and means for forcing air under pressure through said passage and into said clearance space.

CHARLES H. MACFARLAND. HOWARD A. SHUMAKER.

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