US2077572A

US2077572A - Vacuum cleaner

Info

Publication number: US2077572A
Application number: US10759A
Authority: US
Inventors: Lofgren Gustaf Einar
Original assignee: Electrolux Corp
Current assignee: Electrolux Corp
Priority date: 1935-03-13
Filing date: 1935-03-13
Publication date: 1937-04-20
Anticipated expiration: 1954-04-20

Description

G. E. LOFGREN VACUUM CLEANER April 20, 1937.

Filed March 15, 1935 2 Sheets-Sheet 1 7?4 46;, ATTORNEY.

G. E. LOFGREN VACUUM CLEANER A ril 20, 1937.

Filed March 15, 1955 2 Sheets-Sheet 2 I nyvggToR, 7 W

@/M 5 ATTORNEY.

Patented Apr. 20, 1937 VACUUM CLEANER Gustaf Elna: Lofgren, Riverside, Conn., asslgnor to Electrolux Corporation, Dover, Del., a corporation of Delaware Application March 13, 1935, Serial No. 10,759

14 Claims.

My invention relates to vacuum cleaners, and more particularly to vacuum cleaners oi the type wherein the dust separating member is contained within a casing.

One of the objects of my invention is to provide a vacuum cleaner of this type which is provided with a removable receptacle, such as a drawer, for receiving the dust separated from the air stream by the dust separating member. A

receptacle of this kind may be more readily removed and emptied than can a dust bag.

A further object oi my invention is to provide means for mechanically dlslodging dust adhering to the dust separating member, thus causing the dust to be collected in the receptacle. In the embodiment illustrated, this removal of dust is accomplished by shaking the dust separating member.

A still further object of my invention is to provide an improved type 01' indicating means for informing the operator when it is desirable to dislodge dust adhering to the dust separating member.

Another object of my invention is to provide a dust separating member having a maximum surface area.

Further objects and advantages of my invention will be apparent from the following description considered in connection with the accompanying drawings, which form a part of this specificatlon and on which:

Fig. 1 is a cross-sectional view of one embodiment of my invention;

Fig. 2 is a front end view of the device shown in Fig. 1;

Fig. 3 is a cross-sectional view taken on the line 3-3 of Fig. 1;

Fig. 4 is a perspective view of a dust collecting receptacle or drawer;

Fig. 5 is a cross-sectional view on an enlarged scale showing a detail of construction;

Fig. 61s a, cross-sectional view on an enlarged scale showing the dust indicator;

Fig. 7 is a cross-sectional view showing a different embodiment of dust separating member;

and

Fig. 8 is a cross-sectional view taken on the line 88 of Fig. 7.

Referring more particularly to Fig. 1, reference character It) designates a casing made of rigid impervious material, such as sheet metal. Casing l0 preferably comprises an upper stamping I l and a lower stamping l2. These stamplngs are joined along a horizontal line, as is shown at IS. The details of this Joint are shown more particularly in Fig. 5. The edge of upper stamping II is formed with an ofl-set portion H, which is bent back upon itself at IS. A strip ..of rubber or other resilient material l6 has a hook-shaped portion I! which extends between the upper edge of lower stamping I2 and offset portion Screws l8 extend through holes formed in lower stamping l2 and engage threaded apertures formed in the ofi-set portion It. This portion is turned back upon itself in order to provide a greater thickness of material for screws l8 to engage. The heads of screws l8 are concealed under the rounded portion I9 of strip l6. Portion l9 also serves as a bumper so that if the cleaner is accidentally brought into contact with a piece of furniture or the like, the furniture will not be marred.

A motor supporting member 20 is secured within one end of easing l0. Member 20 is formed with a channel portion 2| which rests within a sealing ring 22 of rubber or other suitable material. Screws 23 extend through casing 10 and ring 22 and engage threaded apertures formed in channel portion 2|, thus retaining member 20 securely in place. Sealing ring 22 prevents the passage of air between member 20 and the casing 10. A plurality of lugs 24 are secured to channel portion 2| by bolts 24a and are distributed equidistantly around the circumference thereof. Preferably, three lugs spaced apart are provided.

Reference character 25 designates an electric motor which is provided with lugs 26 spaced 120 apart around the circumference of the motor. Secured in these lugs are pins 21 encircled by springs 28. These pins and springs extend through apertures formed in lugs 24, thus providing a resilient support for the motor. Spacing members 29 may be placed between lugs 24 and 26.

One or more fan rotors 30 are mounted on the shaft 3| of motor 25. In the embodiment illustrated two rotors 30 are provided. The forward rotor is surrounded by a fan housing 32 having a cylindrical portion 83. The other rotor is surrounded by a fan housing 34 having a cylindrical portion 35. Cylindrical portions 33 and 35 are telescoped and the rear edge of each is provided with an outwardly extending flange 86. The housing of motor 25 is provided with a radial flange 31 against which the flanges 36 are clamped by means of clamping ring 38.- Ring 38 is secured to flange 31 by bolts 39. Rings of packing material 40 are provided in order to eflect an air-tight seal between the fan housings and flange 31. Member 28 is formed with a cylindrical portion 4| which is eccentric with respect to channel portion 2|. A sealing ring 42 is provided around the outer circumference of ring 38 and bears against cylindrical portion 4! in order to effect an air-tight seal therebetween. The left hand end of cylindrical portion 4|, as viewed in Fig. 1, serves to support a member 43 having a curved surface and preferably made of wire screen or other stiff, air-pervious material.

A dust separating member 44. preferably made of cloth having a weave such that it will permit the passage therethrough of air, while preventing the passage of dust, is supported over member 43. Dust separating member 44 is secured at 45 to a movable tube 46. Tube 46 is rotatably and slidably mounted in a bushing 4! secured in member 43 and in a bushing 48 supported by a spider 49 supported within member 43. A collar 'end of tube 46 is formed a handle 53, which may be grasped to pull the tube out against the force of spring 5| and to rotate the tube. Dust separating member 44 is somewhat larger than supporting member 43, so that it can be pulled away from member 43 when the tube is pulled out. If the tube is pulled out suddenly, it snaps the dust separating member into stretched condition, thus dislodging dirt from the outer surface thereof. Rotating the tube also agitates member 44 and aids in dislodging dirt. When handle 53 is released, spring 5| snaps the tube back to its normal position.

The left hand end, as viewed in Fig. l, of lower stamping I2 is formed with a rectangular opening 54. A drawer 55 is adapted to be inserted and removed through opening 54. The outer end of drawer 55 is formed with a flange 56 of greater dimensions than opening 54 in order to overlap the opening and bears against the front wall of stamping l2. A sealing strip 51 of rubber or other suitable material is secured to the flange 56 in order to seal the joint between the drawer and the casing. An arm 58 is secured to stamping I2 above the center of opening 54 and extends downwardly so as to be within the drawer 55 when the latter is in place. Ann 58 is formed with a threaded aperture 59. A pin 68 is journalled in a bushing 6| secured in the front wall of drawer 55 and is provided at its outer end with a knurled knob 62 and at its inner end is formed with screw threads 63 which engage threaded aperture 59. Pin 68 thus provides means for fastening the drawer in place and placing sealing ring 51 under compression so as to effect a tight seal.

The rear wall 64 of drawer 55 is cut away, as is clearly shown at 65 in Fig. 4, so as to accommodate the lower portion of supporting member 43 and dust separating member 44. This cutaway portion also makes it possible to withdraw the drawer without interference from arm 58. Inasmuch as drawer 55 is not as wide as lower stamping l2, spacing members 66 are secured within stamping [2 in order to center the drawer and prevent sidewise movement thereof. Deflecting members 61 are secured within upper stamping I l and serve to direct the dust into the drawer and prevent to a great extent accumulation of the dust in the space between the side walls of lower stamping I 2 and the outside of the drawer.

Upper stamping l l is provided with a threaded bushing 68 forming an inlet opening and adapted to receive the threaded end 69 of a hose 18. The other end of hose i8 is adapted to be connected to a suction nozzle or other air cleaning tool. A threaded bushing II is secured within an opening formed in lower stamping l 2 and serves as an outlet for air. Louvers 12 may be provided across the opening in bushing H in order to direct the air upwardly and away from the surface on which the vacuum cleaner is resting. If it is desired to use the device for blowing purposes, hose 18 may be screwed into bushing 1|. As shown in Fig. 1, the convex surface of dust separating member 44 faces the inlet opening with respect to the direction of air flow.

A dust indicating device is incorporated within the handle 53. The inner end of tube 46 opens within the space between dust separating member 44 and the fan rotors 38. The outer end of tube 46 communicates through a passage 13 with a space 14 formed within a member 15 forming part of the handle 53. A tube 16 surrounds the outer end of tube 46 and extends through bushing 52. Tube I6 is provided with apertures 11 which communicate with the space in the casing betweenthe inlet and the dust separating member. The outer end of tube 161s threaded into member 15 at 18. A passageway 19 establishes communication between tube 16 and a space 38 formed between member 15 and a cap 8!. Member 15 and cap 81 are fastened together by means of bolts 82. A cup-shaped member 83 is formed with an outwardly extending flange 84 which is clamped between member 15 and cap 8|. The peripheral portion of the bottom 83a of member 83 serves to clamp the outer circumference of a flexible diaphragm 85 between member 83 and a shoulder 86 formed in member 15. A disc 81 with downturned edges is secured to the center of diaphragm 85 and retains one end of a spring 88, the other end of which bears against member 15. A flat disc 89 is secured to the other side of diaphragm 85 and bears against the bottom 83a of cup-shaped member 83. One or more apertures 83b are formed in bottom 83a to assure that the pressure communicated through passageway 19 will act on diaphragm 85. Discs 8'! and 89 are secured to diaphragm 85 by a round headed rivet 91 or the like which extends through the central opening in the bottom 83a.

An indicating. member 98 is pivoted at 9|,to ears 92 formed on member 83. A spring 93 has one end secured to indicating member 98 at 94 and the other end to a hook 95 formed on member 83. Spring 93 is maintained under tension and tends to rotate indicator member 98 in clockwise direction as viewed in Fig. 5. A flat-bot tomed portion 96 of member 98 bears against the rounded head of rivet 91 carried by diaphragm 85 and prevents the rotation of member 98. Indicator member 98 is formed with a cylindrical portion 98 which is adapted to be rotated in front of an air-tight window 99. Cylindrical portion 98 bears markings so that its position may be determined by viewing it through window 99. These markings may consist in coloring white a part which is visible in the position shown in Fig. 5, and coloring red 9. part I88 which will be visible when the member is rotated sufficiently.

The operation of the above described device is as follows:

Assuming the vacuum cleaner to be assembled as shown in Fig. 1, rotation of the fan rotors II by the motor 2! causes them to draw air into the casing through hose 10. If the cleaning tool attached to the other end of hose II is passed over a dusty surface, the dust will be picked up and carried by the air stream into the casing. The air passes through dust separating member 44 which is supported by screen 43, while the dust is not permitted to pass through. The air discharged from the fan rotors passes through motor 25 as shown by the arrows, and is discharged through outlet opening Il. Due to the sudden reduction in the velocity of the air stream when it enters the casing, a considerable proportion of the entrained dust will be precipitated and will settle in drawer 55. The remaining dust will adhere to the outer surface of the dust separating member 44. When it is desired to remove the dust from the cleaner, the fan is stopped and the dust may be removed from member 44 by pulling out and releasing handle 53, as has been previously described. This shakes the dust loose from the dust separating member and this dust is collected in drawer 55. Thereafter knob 82 is turned so as to disengage threaded portion 83 from arm 58 and the drawer and its contents may be withdrawn from the casing and emptied in any suitable place.

The dust indicating member warns the operator when sufllcient dust has accumulated on the dust separating member to make it desirable to remove this dust. Dust separating member 44 offers a certain resistance to the passage therethrough of air and hence the pressure in the space between the inlet and the dust separating member is higher than the pressure between the dust separating member and the fan. As dust accumulates in the dust separating member it increases the resistance to flow of air therethrough and thus increases this difference in pressure. The higher pressure existihg between the inlet and the dust separating member is communicated to chamber in handle 53 by means of tube I6 and passage 19. This pressure is exerted against one side of diaphragm 85 and tends to move the diaphragm so as to compress spring 88. The lower pressure existing between the dust separating member and the fan is communicated to chamber I4 in handle 53 through tube 46 and passage 13. In chamber 14 this pressure is exerted against diaphragm 85. When, due to the accumulation of dust on the dust separating member, this pressure difference is great enough to overcome the force of spring 88, diaphragm 85 and projection 91 will move to the right as viewed in Fig. 6, and thus permit spring 93 to rotate indicating member in clockwise direction. This will cause the part Hill which. is painted red, or distinguished in some other suitable manner, to appear below window 99. This will warn the operator that the dust should be removed from the dust separating member. This can be done by stopping the motor and shaking the dust separating member, as previously described.

It is not necessary always to empty the drawer after the dust separating member has been shaken. However, if, immediately after it has been shaken and the motor is again started, the dust indicator again shows that there is an excessive pressure drop through the dust separating member, this should be taken as a warning that the drawer should be emptied inasmuch as it contains so much dust that the air stream picks it up and deposits it on the dust separating member.

Figs. '7 and 8 show a somewhat modified embodiment of my invention. This embodiment differs from that illustrated in the previous figures in that the supporting member, here designated by reference character 43' is formed with an undulated surface, star-shaped in cross-section, in order to provide a greater surface. The dust separating member 44 consequently may be made with a greater surface without occupying a greater overall space. The greater the surface of the dust separating member, the less resistance it offers to the passage of. air and hence the longer it may be operated without requiring cleaning. The operation of this embodiment is otherwise similar to that previously described.

While I have shown two more or less specific embodiments of my invention for purposes of illustration, it is to be understood that the scope thereof is to be limited only by the appended claims viewed in the light of the prior art.

What I claim is:

1. In a vacuum cleaner, a casing formed with an air inlet and an air outlet and a drawer open- 4 ing, means for producing flow of air through said casing, a dust separating member in said casing having a horizontal extent, a drawer removable through said opening and having impervious walls extending under said member for collecting dust separated from the air by said members, said drawer having a flange adapted to seal against said casing, an arm secured within said casing and extending to within the space defined by said drawer, one wall of said drawer being cut away to provide for passage past said arm, and means secured to another wall of said drawer for engaging said arm to secure said drawer in said casing with said flange in sealing relationship with said casing.

2. In a vacuum cleaner, a casing formed with an air inlet and an air outlet, means for producing flow of air through said casing, a dust separating member, and means for supporting said member within said casing and maintaining the entire surface of said member curved, the convex side of said member facing said inlet with respect to the direction of air flow, the area of said dust separating member being substantially greater than the area of the supporting means, whereby said dust separating member is folded against said supporting means.

3. In a vacuum cleaner, a casing formed with an air inlet and an air outlet, means for producing flow of air through said casing, a supporting member having an air pervious curved surface,

the convex side of said member facing said inlet with respect to the direction of air flow, a dust separating member supported on the convex side of said member, the area of said dust separating member being substantially greater than the area of said supporting member, whereby said dust separating member is folded against said supporting member, and a removable receptacle located beneath said members for collecting dust separated from the air by said dust separating member.

4. In a vacuum cleaner, a casing formed with an air inlet and an air outlet, means for producing flow of air through said casing, a supporting member having an air pervious curved surface, the convex side of said member facing said inlet with respect to the direction of air flow, a dust separating member supported on the convex side of said member, the area of said dust separating member being substantially greater than the area of said supporting member, whereby said dust separating member is folded against said supporting member, an agitator member slidablymounted in-said supporting member and in said casing and secured to said dust separating member and movableto straighten out the folds in said dust separating member, one end or said agitator member extending outside said casing, and a removable receptacle located beneath said dust separating member for collecting dust.

5. In a vacuum cleaner, a casing formed with an air inlet and an air outlet, a motor fan unit within said casing for producing flow of air therethrough, supporting means for said unit, a wire form having a convex surface'facing said inlet secured to said'supporting member, a dust separating member supported on the convex side of said form, the area of said dust separating member being substantially greater than the area of said wire form whereby said dust separating member is folded by the air-flow against said wire form, and a removable-receptacle located beneath said dust separating member for collecting dust.

6. .In a vacuum cleaner, acasing formed with an inlet opening-and an outlet opening, means for producing flow of -air through said casing, a dust separating member in the path of air flow, a movable hollow member secured to said dust separating member and formed with an opening on one side of said dust separating member, and differential pressure responsive means carried by said hollow member and subjected to the pressure therein.

7. In a vacuum cleaner, a casing formed with an inlet opening and an outlet opening. means for producing flow of air through said casing,--a dust separating member in the path of air flow, a movable hollow member secured to said dust separating member and formed with an opening on one side of said dust separating member, a movable diaphragm carried by said hollow member and subjected on one side to the pressure therein and means for communicating the pressure on the other side oi said dust separating member to the other side of said diaphragm.

8. In a vacuum cleaner, a casing formed with an inlet opening and an outlet opening, means for producing flow of air through said casing, a dust separating member in the path of air flow, a movable hollow member secured to and extending through said .dust" separating member and having an opening on one side thereof, a movable diaphragm carried by said hollow member and subjected on one side to the pressure msrem a tube surrounding said hollow member and having an opening on the other side of said dust separating member, and means connecting said tube with the other side or said diaphragm 9. In a'vacuum cleaner, a casing formed with an inlet opening and an outlet opening, a motor fan unit in said casing for producing flow of air therethrough, a dust separating member between said inlet and thefan, a slidably mounted .tube extending through said casing and being secured to "and extending through said dust separating member, said tube'having an opening communicating with the space between said dust separating member and said fan, a diaphragm carried by said tube outside said casing and exposed on one side to the pressure within said tube, a second tube rigidly connected to the first mentioned tube and extending through said casing and communicating with thespace between said-inlet and said=dust separating member, and means con necting said second tube with the other side of said diaphragm.

10. In a vacuum cleaner, a-casing formed with an inlet opening and'an outlet opening, a motor fan unit in said casing for producing flow or air and extending through said casing and communicating with the space between said inlet and said dust separating member, said handle member -formed with a passage connecting said second tube with the other side of said diaphragm.

ll. In a vacuum cleaner, a casing formed with an inlet opening and an outlet opening, a motor fan unit in said casing for producing flow oi air therethrough, a dust separating member between said inlet and the fan, agitating means for said dust separating member comprising two tubes. one within the other, extending through said casing, a hollow handle member secured to the outer ends of said tubes, the longer of said tubes extending through and being secured to said dust separating member and communicating with the space between said dust separating member and said fan, said agitating means being reciprocably.

mounted and resilient means tending to cause movement thereof in one direction, and a diaphragm mounted in said hollow handle and exposed on one side to the pressure within-said longer tube, the shorter tube communicating with the space between said inlet and said dust separating member and with the other side of said diaphragm.

12. In a vacuum cleaner, a casing formed with an air inlet and an air outlet, means for producing flow of air through said casing, a supporting member of rigid air pervious material,

said member being generally conical in shape and having an undulated surface to increase the area thereof, and a dust separating member supported on said member, the area of said dust separating member being substantially greater than the area of said undulated surface.

13. In 'a vacuum cleaner, an elongated noncirc'ular casing, a transverse partition disposed within-said casing and secured in air-tight relation to the interior thereof to provide separate compartments within said casing capable of sustaining different pressures, a motor-fan unit supported "irom' said partition and arranged to produce a sub-atmospheric pressure within one of said compartments, said partition being formed with an aperture for flow of air produced by said motor-tan unit froms'aid one 01' said compartments, said partition serving to strengthen said non-circular casing against atmospheric force actingon the exterior of said one oi. said compartments, and a dust separating member disposed in said one of said compartments in the path or flow of air therethrough.

14. In a vacuum cleaner, an elongated casing including a rounded upper shell and a substan- .,tially flat bottomed lower shell, said shells being joined' together along a continuous air-tight longitudinal seam. said casing being formed with an inlet opening adjacent to one end and an outlet opening adjacent to the other end, said openings being disposed wholly on one side of said seam, transverse partition means within said casing between said openings and secured in air-tight relation to both said shells to provide separate compartments within said casing capable of being subjected to different fluid pressures, a motorian unit supported from said partition means and arranged to produce sub-atmospheric pressure within the compartment communicating with said inlet opening and to produce pressure higher than atmospheric in the compartment communicating with said outlet opening, said partition means serving to reenforce said casing against atmospheric pressure acting on the exterior of the first-mentioned compartment and against internal pressure acting on the secondmentioned compartment, and a dust separating member disposed in said first-mentioned compartments in the path of flow of air from said inlet opening to said motor-tan unit.

GUSTAF EINAR LOFGREN.