US2135036A - Vacuum cleaner - Google Patents

Description

Nov. 1, 1938.

J. F. R. KARLSTROM VACUUM CLEANER Filed NOV. 5, 1936 2 Sheets-SheetI l N 0V-,1, 1938- J. F. R. KARLsTRoM y 2,135,036

VACUUM CLEANER` Filed Nv. 5, 193s 2 sheetssheet 2 ATTORNEY.

Patented Nov. 1, 1938 UNITEDv STATES VACUUM CLEANER Johan ,Fredrik Robert .Karlstrom, Bo, Sweden, assignor to Electrolux Corporation, Dover, Del., a corporation of Delaware Application November 5, 1936, Serial No. 109,241 In-Germany November 8, 1935 14 claims.' (01.183-35) A My invention relates to vacuum cleaners. Heretofore it has been the common practice to provide a vacuum cleaner with a dust bag or other dust separating member through which all of the air is forced to pass. This dust separating member not only imposes a resistance to the flow of air, thereby decreasing the efficiency of the vacuum cleaner, but in order that this resistance shall not rise beyond permissible limits as dust accumulates, it .has been necessary to make the dust bag many times larger than would be required to accommodate the necessary volume of dust. In other Words, the size of the dust bag is determined by the permissible resistance to ilow of air rather than by the volume of the dust accumulated.

One of the objects of my invention is to provide an eicient and dependable arrangement for separating dust `from air which involves no dust bag at all, or a dust bag of only suicient size to accommodate the dust accumulated.

Further objects and advantages of my `invention will be apparent from the following description considered in connection with the accompanying drawings, which form part of this specication, and of whichz- Fig. 1 is a cross-sectional view of one embodiment of my invention;

Fig. 2 is a. cross-sectional view line 2-2 of Fig.. 1;

Fig. 3 is a cross-sectional view of another embodiment of my invention;

taken on the Fig.V 4 is a cross-sectional view of a still fur-v ther embodiment of my invention, and

Fig. 5I is a cross-sectional view taken on the line 5-5 of Fig. 4.

Referring fmore particularly to Fig. 1, reference character ID designates the lower part of a' vacuum cleaner housing mounted on wheels or casters II. One end of housing I is formed as 'a suction nozzle opening I2 which is located adjacent to the surface supporting the wheels II. A drawer I3 is removably positioned within housing I0 and is provided with a handle I4 by which it may be removed.

A hollow conical member I is secured to housing I0 and is provided at its upper and smalerv inlet opening 2|) to the impeller.

Disposed within conical member I5 is a second conical member 25, the walls of members I5 and 25 preferably vbeing substantially parallel. Member 25 is formed with a plurality of slits 26 and preferably guide vanes 21 are provided adjacent to these slits. As will be seen from Fig. 2, these guide vanes are so directed as to divert air rotating in a clockwise direction within member 25 to pass through the slits 26. It will be seen that conical member 25 is disposed between impellers I8 and the smaller end of conical member I5.

A third conical member 2B is secured to the lower end of motor I'I with its smaller end below its larger end and extending upwardly into the space within conical member 25. The housing of motor I'I is provided with openings 29 at the lower end and openings 30 at the upper end to permit passage of air through the motor. Openings 29 are disposed within conical member 28. The upper end of the motor is enclosed within a capv 3| formed with outlet openings 32. If desired, a filter 33 may be disposed Within the space enclosed within cap 3|.

A passageway 34 extends radially outwardly through conical member I5 at a point adjacent to impell'er I8 therein. rA dust bag 35 is secured with its interior in communication with passageway 34 by means of a flange 36. A handle 31 ls plvoted to housing I0 and serves for moving the vacuum cleaner over the surface to be cleaned.

The operation of the above described device is as'follows:.-

Rotation of impeller I8 by motor II causes air to be drawn in through nozzle opening I2 and As the vacuum cleaner is passed over a surface to be cleaned, dust and other particles of dirt will be drawn in with this air. In passing through screen 2I any large particles such as matches, needles and pins or the like will be separated from the air and fall into drawer I3. 'I'he ordinary particles of dust and dirt pass through the screen and are acted upon along with the air by the impeller. This impeller not only produces flow of air through 'the vacuum cleaner, but imparts to the air and dust discharged therefrom a. vvery rapid circular motion which results in centrifugal force acting on the particles. The rotating air and dust in seeking an outlet from the cleaner, is forced to pass upwardly along the inner wall of vconical l member I5 in a helical path. However, the dust particles having a much greater mass than air molecules, the effect of centrifugal force upon the former is much greater than on the air and causes the dust Ato spiral vdownwardly within maximum diameter.

member I5 in seeking a circular path of maximum diameter. The heavier of the dust particles hence travel in a path having an axial directional component opposite 'to that of the air to the point of maximum diameter within conical member I5 and are carried radially outwardly through passageway 34 which communicate with the interior of conical member I5 at its point of A comparatively small percentage of the air passing through the cleaner also paes through passageway 34. This air and dust passes into dust bag 35 where the dust is entrained and the air passes through the material of the bag to the atmophere. Due to the fact 'that' only a small percentage of the total quantity of air passes through the bag, the resistance to the flow of this air is not great, even though the bag is substantially full of dust. Consequently,.the size of the bag need only be sumciet to accommodate the volume of dust and need not be designated extra large for the purpose of reducing resistance to air flow.

The air and lighter particles of dust are forced to spiral upwardly within member I5 until they strike the end wall I6 and are then forced tov spiral downwardly around the outside of conical member 25 and pass around the lower open end of this member into the interior thereof. Much of the dust still entrained with this air will` be thrown radially outwardly when the air is forced to pass to the interior of member 25 and will join the air discharged from the impeller and will again be subjected to the centrifuging action tending to cause it to pass to the place of maximum diameter within member I5 and thence through passageway 34 to the dustbag.

Dust whichY still accompanies the air around the lower end of member 25 makinga second pass in an axial direction away from impeller IB` is again subjected to a similar action within this member as was described in connection with member I5. However, due to the provision of slits 26 and vanes 21 this dust will pass outwardly through the slits and be again subjected to a centrifuging action in the space between conical members I5 .and 25.

it is forced to spiral downwardly around motor decreasing diameter.

I1 and into conical member 28. Within member 28 centrifugal force acting on any remaining dust causes it to spiral upwardly along the inner wall of the member and to pass therefrom to the stream of air spiraling upwardly Within member 25, where it will again be subjected to a centrifuging action. The air thus freed in successive passes in the same direction from dust passes through openings 29 into the motor housing, where it serves to cool the motor and is discharged through openings 30, filter 33, if one be provided, and openings 32 to the atmosphere. Filter 33 may be impregnated with a disinfectant for killing any germs which have such a small mass that they are not separated from the air by centrifuging.

It will be noted that the air in flowing from the impeller to the openings 29 in the motor is caused to travel in a spiral path of generally Consequently, the further the air goes from the impeller, assuming it to travel with aconstant linear velocity, the greater must be its angular velocity. The angular velocity -of the air immediately after it has left the impeller is suiiicient to separate the heavier particles, while the lighter particles are/separated as the angular velocity of the air increases.

The embodiment shown in Fig. 3 differs from that shown in Fig. 1 in the fact that the dust bag is replaced by a settling chamber formed in the drawer I3. A partition 40 divides the drawer into atray 4I and a settling chamber 42. Passageway 34 communicates with one end of the settling chamber, while partition 40 is provided with a restricted opening 43 which establishes communication between the settling chamber and the inlet 20 to the impeller.

Also, in this embodiment the third conical member, here designated by reference character 28a is mounted to rotate with impeller I8. As previously explained, the angularv speed of the air increases as it passes through the device due to the decrease in the diameter of the circular path which it is forced to follow.' However, the frictional resistance to the flow of air may tend to prevent this increase. By causing the conical member, such as member 28a, to rotate in the same direction as the air this frictional loss may be eliminated.

In operation, the dust and small quantity of air passing through passageway 34 as explained in connection with Fig. 1, passes into settling chamber 42. Due to the great cross-sectional area of this chamber as compared with that of passageway 34, the velocity of' air ow through the chamber is greatly reduced and most of the dust settles therein. The nir and a small amount of the lighter particles which do not settle pass through opening 43 and join the stream of 'clust laden air which pass to the impeller through inlet 20.

In Fig. 4, an embodiment of my invention is shown in conjunction with a vacuum cleaner of the so-called pot" type. The lower part of the vacuum cleaner consists of a container 50 adapted to stand on 'the iioor. This container is provided with an inlet opening 5I to which may be connected a flexible hose leading to a suction nozzle, the nozzle being moved over the floor of the surface to be cleaned while the rest of the vacuum cleaner remains stationary. 'I'he upper end of container 50 is formed with a bell-mouth 52 within which isremovably supported conical member I5.

The construction of the dust separating arrangement shown in Fig. 4 diiers from that described in connection with Fig. 1, only in the fact that an opening 53 is provided in the outer wallof conical member I5 adjacent to end wall I6. This opening communicates with a passage 54,'also formed in conical memberv I5, and which leads downwardly to communicate with the interior of container 50. In this embodiment container 50 constitutes a settling chamber.

lilso,l as seen in Fig. 5, the passageway 34 leading from the point of maximum diameter of conical member I5 to the settling chamber may advantageously be arranged obliquely, and in such a manner as to aid in the flow therethrough of dust rotating in a clock-wise direction within member I5. Passageway 53 may likewise be arranged in this oblique manner. The operation of this embodiment is as followsz- Rotation of impellers I8 by the 'motor causes air and entrained dust to be drawn in to the container 50 through inlet 5I. Screen 2| preventsiany large particles from reaching the impeller. The air and entrained particles are discharged from the impeller with a rapid rotary motion and the particles are centrifuged in the same manner as described in connection with the embodimentI shown in Fig. 1. However, lighter particles which reach the upper end of the space between conical members I and 25 may pass therefrom under the infiuenceof centrifuging action through passageways 53 'and'54 to within container 5U. The air admitted to the container 50 along with the air admitted through passageway 34 and passage 54 joins the main stream of air flowing through the inlet 20 to the impeller and any dust not settling from the air is again subjected to the centrifuging action.

While l have described three more or less specific embodiments of my invention it is to be understood that this has been done for purposes of illustration only, and that the scope of my invention is not to be limited thereto, but is to be determined by the appended claims viewed in the light of the prior art.

What I claim isi- 1. In a vacuum cleaner, a first hollow conical member, a centrifugal impeller disposed within said conical member and spaced annularly therefrom adjacent to the larger end thereof for causing flow of air and entrained solid particles andl for imparting rotary motion thereto, the smaller end of said conical member being spaced axially from said impeller, a second hollow .conical member within said first conical member and disposed between the smaller end of lsaid first member and the impeller, the walls of said conical members being substantially parallel, means forming a passageway for air from the interior of said `second conical member to atmosphere, and -means forming a passageway extending radially outwardly from the interior of said rst conical member at a point adjacent to said impeller.

2. A vacuum cleaner as defined in claim 1 in which said second conical member is formed with apertures intermediate the ends thereof.

3. A vacuum cleaner as defined in lclaim 1 in which said second conical member isV formed with -apertures intermediate the ends thereof and including guide vanes disposed adjacent to said apertures and positioned so as to direct flow through said apertures of rotating particlesA from withinsaid inner conical member.

4. In a vacuum cleaner, a first hollow conical member, a centrifugal impeller disposed within said corneal member and spaced annularly therefrom adjacent to the larger end thereof for causing flow of air and entrained solid particles andl for imparting rotary motion thereto, the smaller end of said conical member being spaced axially from said impeller, a secondhollow conical member within said first conical member and 'clisposed between Athe smaller end of said first member and the impeller, the walls of vsaid conical members being substantially parallel, an electric motor for driving said impellerv disposed within said second conical member and formed with a passage for conveying air from within said second conical member to atmosphere, and means forming a passageway extending radially outwardly from the interior of said firstk conical member at a point adjacent to said impeller.

5. Ina vacuum cleaner, a first hollow conical member, a centrifugal impeller disposed within said conical member and spaced annularly therefrom adjacent to the larger end thereof for causing ow of air'and entrained solid particles and for imparting rotary motion thereto, the smaller end of said conical member being spaced axially member disposed within said second memberl withthe smaller end of the third member adjacent to the larger end of the second member and with the larger end of the third member between the ends of the second member, an electric lmotor for driving said impeller disposed within said second member and having one end extending into said third member, said motor/being formed with a passage opening within said third member and leading to atmosphere, and means forming a passageway extending. radially .outwardly from the interior of said rst conical member at a pointadjacent to said impeller.

6. In a vacuum cleaner, a first hollow conical member, a centrifugal impeller disposed within said conical member and spaced annularly therefrom adjacent to the larger end thereof for causing flow of air and entrained solid particles and for imparting rotary motion thereto, the smaller end of said conical member being spaced axially from said impeller, a second hollow conicalfmember within said rst conical member and disposed between the smaller end of said first member and the impeller, the walls of said conical members being substantially parallel, an electric motor for driving said impeller within said second conical member and having an end adjacent the larger end of said second member, a third conical member supported at the smaller end by vsaid end of the motor and extending into the, space between said motor and said second end of said .conical member being spaced axially from said impeller, a second hollow conical member within said rst conical member and disposed between the smaller end of said rst member and the impeller, the walls of said conical members being substantially parallel, an electric motor for driving said impeller within said second conical member, and-having an end adjacent the larger end of said second member, a third conical member mounted for rotationA with said impeller and having its larger end disposed within the space between said motor and said secondl member, said motor being formed with a passage opening Within, said third member and `leading to atmosphere, and means forming a passageway extending radially outwardly from the interior of said first member` at a point adjacent to said impeller.

8. In a vacuum cleaner, ahollow member having curved inner wall surface, a centrifugal impeller disposed within said hollow member andv spaced annularly therefrom for causing ow. of air and entrained solid particles and for imparting rotary motion thereto, means forming an inlet passage for said impeller, said hollow memberextending axially beyond said impeller and the cross-sectional area of said hollow member dehcreasing at points progressively more remote axially from said impeller, means forming a passageway for air from said hollow member to the atmosphere, means forming a settling chamber,

means forming a passageway extending radially ing rotary motion thereto, means forming an inlet passage for said impeller, said hollow member extending axially beyond said 4impeller and the cross-sectional area of said hollow member decreasing at points progressively more remote axially from said impeller, means forming a passageway for air from said hollow member to the atmosphere, a removable dust drawer forming a settling chamber, means forming a passageway extending radially outwardly from the interior of `said hollow member at apoint adjacent to said impeller and communicating with said dust drawyer, and means establishing communication beltween said dust drawer and said inlet passage to said impeller.

10. In a vacuum cleaner, a hollow member having curved inner wall surface, a centrifugal impeller disposed within said hollow member and spaced annularly therefrom for causing ow of air and entrained solid particles and for imparting rotary motion thereto, said hollow member extending axially beyond said impeller. and the cross-sectional area of said hollow member decreasing at points progressively more remote axially from said impeller, means forming a passageway for air from said hollow member tothe atmosphere, means forming a passageway extending radially outwardly from the interior of said hollow member at a point adjacent to said impeller, and means forming a passageway extending radially outwardly from the interior of said hollow member at a place therein of reduced diameter.

11. In a vacuum cleaner, a first hollow conical member, a centrifugal impeller disposed within said conical member and spaced annularly therefrom adjacent to the larger end thereof for causing ow of air and entrained solid particles and for imparting rotary motion thereto, the smaller end of said conical member being spaced axially from said impeller, a second hollow conical member within said rst conical member and disposed between the smaller end of said lrst member'and the impeller, the walls of said conical members being substantially parallel, an end wall joining the smaller .ends of said conical members, means forming a passageway extend-aL ing radially outwardly from the interior of said first conical member at a place adjacent to said impeller, and means forming a passageway ex- 12. In a vacuum cleaner, a hollow member having curved inner wall surface, a centrifugal impeller disposed Within said hollow member and spaced annularly therefrom for causing flow of airy and entrained solid particles and for imparting rotary motion thereto, said hollow member extending axially beyond said impeller and the cross-sectional area of said hollow member decreasing at points progressively more remote axially from said impeller, means forming a passageway for air from said hollow member to the atmosphere, means forming a channel extending radially outwardly from the interior of said hollow member at a point adjacent to said impeller, means forming a channel extending radially outwardly from the interior of said hollow member at a place therein of reduced diameter, means forming a settling chamber, both of said channels communicating with said settling chamber, and

- means establishing communication between said settling chamber and the inlet of said impeller. 13. In a vacuum cleaner, a hollow member having curved inner wall surface, a centrifugal impeller disposed within said hollow member and spaced annularly therefrom for causing flow o f air and entrained solid particlesand for imparting rotary motion thereto, said hollow member extending axially beyond said impeller and the/ cross-sectional area of said hollow member decreasing at points progressively more remote axially from said impeller, means forming a passageway for air from said hollow member to vthe atmosphere, said impeller being formed with an inlet opening, a coarse screen disposed across the path of flow of air to said inlet, a removable receptacle, a partition dividing said receptacle into two parts, one of said parts being disposed below said screen and the other of said parts constituting a settling chamber, and means forming a passageway extending radially outwardly from the interior of said hollow member at a'point adjacent to said impeller and communicating with said settling chamber, said partition being formed with an opening for establishing communication between said settling chamber and said inlet opening.

14. In a vacuum cleaner, structure forming a separator chamber having a conical wall, said chamber being formed with an inlet adjacent to its end of maximum diameter, means for causing flow of dust laden air through said chamber and cooperating with said structure to impart rotary motion to said dust laden air, a hollow conical member within said chamber, and disposed between its end of minimum diameter and said inlet, the surface of said conical member being substantially parallel to said conical wall, means forming a passageway for air from the interior of said conical member to atmosphere, and means forming a passageway extending radially outwardly from the interior of said conical wall adjacent to its point of maximum diameter.

JOHAN FREDRIK ROBERT KARLSTROM.

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