US 2155669 A
Description (OCR text may contain errors)
April A25, 1939.
G. E. LOFGREN VACUUM CLEANER Filed March 12, 1955 3 Sheets-Sheet 1 '/02 lNvE TOR,
April 25, 1939. G. E. LOFGREN VACUUM CLEANER Filed March l2, 1955 3 SheetS--Sheetl 2 April25, 1939. f G ELQFGRE 2,155,669
VACUUM CLEANER Filed March l2, l1935 3 Sheets-Sheet 3 A? aIyENTOR, BY b 6.5 ATTORNEY.
Patented Apr. 2,5, 1939 UNITED STATES' VACUUM CLEANER Gustaf Einar Lofgren, Riverside, Conn., assignor to Electrolux Corporation, Dover, Del., a corporation of Delaware Application March 12, 1935, Serial No. 10,620
My invention relates to vacuum cleaners and more particularly to vacuum cleaners of the enclosed bag type.
One of the objects of my invention is to provide a vacuumcleaner of this type in which the bag may be more readily removed for emptying than has been the case heretofore. In the past, cleaners of this type having a casing adapted to be supported horizontally upon a horizontal surface have been formed with an opening in a vertical plane through which the bag is removed. The open mouth of the bag is secured in this opening, and in order to remove the bag when partially filled with dirt, it has been convenient to stand the cleaner on end in order that the dirt will not fall out when the cleaner is opened. In order to render this unnecessary, the cleaner in accordance with the present invention is formed with an opening for withdrawal of the dust bag located in an inclined plane. Thus, the advantages of a horizontal construction are retained, and itis also convenient to remove the bag without first standing the cleaner on end. i
The inclined dust bag opening has a further advantage. It has heretofore been proposed to employ a dust bag which is longer than the available space within the cleaner casing in which it is received. Such a bag has, of course, a greater wall surface than one of equal or shorter length than the space, and consequently offersy less resistance to the passage of air. Necessarily, the walls of the bag arefolded in order that it may be received in the smaller space and difficulties have been experienced in properly inserting the bag due to the fact that most of the folds are apt to occur adjacent to the mouth of the bag and hence tend to block the passage of dust ladened air into the bag. Even if the fan is operating during insertion of the bag, and hence producing a suction effect tending to draw the bag into the space, this tendency will cease -as soon as the closedend of the bag strikes the end of the space. Thereafter, the suction simply tends to expand the bag and. presses the folds, which are formed adjacent to the open en`d of the bag by the opersides of the space. I have determined, however,
that if the mouth of the bag is held in a position 6 inclined with respect to the lengthwise extent of the space, as it' is in a cleaner in accordance with the present invention due to the inclination of the dust bag opening, the tendency of the air flow to expand the baghas the effect of preventing the formation of folds adjacent to the mouth ator forcing this end into the space, against the.
of the bag, where the axis of the bag curves from an inclined to a horizontal position, and causes the folds to be distributed more towards the closed end of the bag. Consequently, the inclined opening aids in the proper insertion of the long bag.
v.Another object of the invention is to reduce 5 lthe noise produced by the air discharged from the cleaner. To accomplish this, I cause the air to pass through a comparatively long passage after leaving the fan and to be discharged to the atmosphere through a plurality of openl0 ings, rather than through a'single opening. Thus the noise of the fan is deadened before the airis discharged from the cleaner and the roar produced by the rapid flow of air through a single opening is greatly reduced. 15
It is desirable that vacuum cleaners should be available for blowing purposes, as well as for their normal use as suction cleaners, and one of the objects of my invention is to provide connections for a hose for both blowing and suction purposes at the same end of the vacuum cleaner.
A further object of my invention is the provision of a casing for a vacuum cleaner, particu- -larly of the enclosed bagtype, including two stampings, preferably an upper and a lower one. Heretofore, casings for vacuum cleaners of this type have been cylindrical with an opening at either end, thus necessitating detachment andA removal of the interior parts if access to them becomes necessary for purposes of repair'or so forth. A two-piece casing, on the other hand, makes it possible to secure the interior parts to either of the stampings, and thus access thereto is possible by merely removing the other stamping. I'he original assembly of the device is also facilitated inasmuch as the interior parts may be secured to one stamping before the other stamping is secured in place.
A casing made in this manner has many other advantages, some of the more important of which will be mentioned. In the event of injury to one piece, only that piece need be replaced, thus reducing the cost of repairs. In this connection also, if the interior parts are secured to the undamaged stamping, the injured stamping may be replaced without disturbing them. 'I'his will usually be the case if the interior parts are secured to the lower stamping, as shown in this application, inasmuch as the upper stamping is the one more aptfto be injured. With a casing comprising two stampings, one or both ends of the casing may be integral with these stampings, rather than separate pieces, as is necessary with a cylindrical casing, thus making a cheaper construction while eliminating opportunities for leaks. Stampings may be of most any desired shape, thus making possible a wide latitude in the design of the casing so that it may best serve its intended purposes. For instance, reinforcing ribs may be stamped directly in the casing. Also, the joint between the two stampings may be made air-tight, without soldering or riveting, by the use of a strip of packing material, such as rubber. The suction produced within the casing exerts a large force tending to draw the abutting edges of the stampings together, and thus effects a tight seal, regardless of whatever other means are employed to fasten the parts together. Other advantages of this type of casing will be apparent from description contained hereinafter.
Another object of my invention is to provide means whereby the plurality of outlet openings above referred to are closed when a hose is attached to the blowing opening, this means also serving to close the hose connection blowing opening when no hose is connected.
Further objects and advantages of my invention will be apparent from the following description taken in connection with the accompanying drawings forming a part of this specification and of which:
Fig. 1 is a. side view of a vacuum cleaner in acv cordance with my invention;
Fig. 2 is a front view of the device shown in Fig, 1;
1 Fig. 3 is a rear view of the device shown in Fig.
Fig. 4 is a cross-sectional view taken on the line 4--4 of Fig. 1;
Fig. 5 is a cross-sectional view taken on the line 5-5 of Fig. 2;
Fig. 6 is a cross-sectional view taken on the line 5-,6 f Fig. 5;
Fig. 'I is a cross-sectional view taken on the line 1-1 of Fig. 5;
Fig. 8 is a cross-sectional view on an enlarged scale taken on the line 8 8 of Fig. 7;
Fig. 9`is a cross-sectional view on a similar scale taken on the line 9 9 of Fig. '1;
Fig. 10 is a cross-sectional view of a portion of the cleaner as shown in Fig. 5, but with a hose connected in position for blowing;
Fig. 11 is a perspective view of a part of the vacuum cleaner shown in the preceding figures;
Fig. 12 is a cross-sectional view on an enlarged scale showing the dust indicator;
Fig. 13 is a cross-sectional view taken on the line I3I3 of Fig. 12; and
Fig. 14 is a cross-sectional view taken on the line I4I4 of Fig. 13.
Referring to the drawings, reference character I designates generally a hollow casing made of metal or other rigid sheet material. Casing III comprises anupper part or shell II and a lower part or shell I2. If, the casing is made of sheet metal the parts are preferably formed by stampmg.
Lower part I2 is clearly shown in Fig. l1. Secured within part I2, as by Welding, riveting or the like, is a U-shaped channel member I3, which serves as a motor support. The upper horizontal edge of part I2 is formed with a V-shaped groove I4 adapted to receive a bead I5 of rubber or other resilient material. Bead I is formed with a dove-tailed portion I6, (Fig. 6) and the lower horizontal edge of upper part I I is stamped to form an edge I1 which extends into the upper groove formed by the dovetail. Bead I5 serves the dual purpose of providing an air-tight seal between the upper and lower parts and of providing a bumper or guard around the cleaner casing to prevent the marring of furniture with which the casing accidentally may come in contact. Upper part II of the casing is secured to channel member I3 by means of a plurality of screws or the like I9, and is 4thus held rigidly with respect to the lower part I2.
The forward part of the casing comprises a casting I9 into which are secured, as by screws 23, the forward ends of both the upper and lower parts II and I2, respectively. Casting I9 is formed with a large circular opening 29 located in an inclined plane, as is clearly shown particularly n Figs. 5 and 12. A cylindrical wall 2| (Fig. 7) extends rearwardly from the opening 2D to the rear of casting I9. 'I'he casting is formed with an intermediate transverse wall 22, which extends across the entire casting below the opening 20. A cylindrical inner casing 25 is positioned within casing I9, and is joined to the rear end of cylindrical part 2l of casting I9. Cylindrical part 2I and inner casing 25 provide a space within which is positioned a dust bag 25. The length of bag 26 is preferably somewhat greater than the space into which it is inserted, so as to obtain the benets of an increased wall surface. When in place, the walls of the dust bag are folded, as shown in Fig. 5. A cage 21 made of wire mesh or perforated plate may be located within inner casing 25 in order to space the dust bag from the casing. This aids the passage of air through the walls of the dust bag. The forward open end of the dust bag is secured to a ring 28 having an outwardly extending flange 29 (Fig. 12). A packing ring 39 is secured over the edge of flange 29 and the flange and packing ring are adapted to be clamped between the forward face of casting I9 anda cover member 3|, which is secured in place by two or more spring clips 32. Cover member 3| is formed with a threaded central opening 35 which is adapted to receive the threaded end of a hose 39.v
Channel member I3 is provided with a plurality of inwardly extending lugs 31, which are preferably made of a phenol condensation product or other electric insulating material. An electric motor 39 is'supported from lugs 31 by means of pins 39 extending through holes in the lugs 31 and in lugs 40 formed on the motor. Pins 39 may be surrounded with coil springs in order to give the motor a resilient mounting.-
Secured to the shaft of motor 39 are one or more fan rotors 4I. These rotors are surrounded by a fan housing 42, which has a cylindrical portion secured to a flange 45 formed on the motor. Flange 45 carries an annular sealing ring 45 of resilient material, which also engages the rear end of cylindrical inner casing 25. Sealing ring 46 effects an air-tight seal between the motor and casing 25, while permitting a slight amount of movement between these parts.
Motor 38 is formed with openings 41 in the forward bearing plate, and all of the air discharged from fan rotors 4I is forced to pass through these openings. The rear part of the motor is formed with a single opening 49, to which is secured a conduit' member 49, which may preferably be made of rubber or other flexible material. The shape of member 49 may best be seen from Figs. 5 and 6. The lower rectangular vend 50 of member I49 receives a rectangular piece 51 and an inner convex top 68. A strip of asbestos or other heat-resisting flexible material 59 is preferably placed between the top 58 and inner casing 25. The portion of lower part I2 of the casing which forms the bottom 55 of channel 52y is preferably corrugated and is shown in Figs. 4 and 411 in order to provide a maximum heat transfer surface and to stiffen the plate. The forward end of channel 52 communicates with a space 60 (Fig. 5) formed in the casting |9 between the bottom of the casting and transverse wall 22. Casting I9 is formed with a forward threaded aperture 6| which also communicates with the space 60. Aperture 6| is adapted to receive a threaded end of hose 36 when it is desired to use the device for blowing purposes. Wall 22 is formed with openings 62 adjacent either end thereof, which openings communicate with a space 65 bounded by wall 22, circular part 2| and the outer wall of the casting. A valve member 66 is pivoted at 61 and serves to close either openings 62 on the one hand or opening 6| on the other. A spring 68 serves to normally hold valve member 66 in the position shown in Figs. '1, 8 and 9, so that the central part 69 of the valve member bears against the material of casting I9 surrounding opening 6 I, and thus serves to close the opening.
The hose 36 is provided with an extension 10, which, when the hose is screwed i'nto opening 6i presses valve member 66 to the position shown in Fig. 10. In this position the end portions 1| of the valve member bear against the lower side of wall 22 around the openings 62, and these openings are thereby closed. It will be seen that the end portions 1|,of the valve member lie in the same plane, while the central portion 69 is in a plane parallel theretobut spaced somewhat therefrom.
-Space communicates with a similar space 12 bounded by casing III, inner casing 25 and member 56. Upper part II of the casing is formed with a plurality of louver openings 15, which establishcommunication between space 12 and the atmosphere. shown in Fig. 1, so as to direc-t air discharged therethrough upwardly and away from the surface supporting the cleaner.
The dust indicator is located in a recess formed in the upper part of casting I9. The indicator includes a cap-shaped member 11 sec-ured in place within the recess by means of a member 18 having openings 19 therethrough which communicate with the space immediately outside of dust bag 26. The upper end of member 11 is formed with an annular flange which receives and holds in place a piece of glass or other transparent air-irnpervious material 80. A visual indicating member 8| is pivoted at 82 to the bottom of the cap-shaped member 11. Member 8| comprises an arcuate portion 8'5 adapted to be rotated underneath an opening 86 formed in the casting I9 above the glass 80. The upper convex surface of part bears markings of a nature to indicate its position. A weight 81 is secured to indicator member 8| and tends to cause the member to rotate in a clockwise direction, as viewed in Fig. 12, about pivot 82. Secured between the bottom of Ycap-shaped memberA 11 and member 18 is a flexible diaphragm 88 tothe central part of which is secured a plate 89 and a flanged disc 90. -A rivet or the like 9| passes through disc 90, diaphragm 88 and plate 89, and bears aaginst a horizontal portion-92 of indicator member 8|. A spring 95 is retained between member 18 and Openings 65 are inclined ask dust bag ring 28 is formed with one or more depressed portions 98 which extend into groove 91 and are provided with openings 99, which establish communication between the space within cap 3| and groove 91. Inasmuch as the space Within cap 3| is directly in communication with the interior of dust bag 26, the pressure existing within the dust bag is communicated through openings 99, groove 91 and passage 96 to within recess 16. Cap-shaped member 11 is formed with one or more openings |00 whereby this pressure is communicated to within the cap-shaped member, and acts upon the upper side of diaphragm 98.
The bottom of part I2 of the casing and the bottom of casting |9 are formed with downwardly extending portions |0| and runners |02 are secured to the lower ends of portions I 0|.
rIfhese runners serve to support the cleaner on the l ycasing may be rounded, as shown at |08 in Fig.
l, and formed with a vertical iin |09 from which extends the electric conductor lead ||0.
The operation of the above described device is as follows:
If the hose 36 is connected to suction opening 35, as shown in Figs. l, 2 and 5, and the motorfan unit is operated, air will be drawnY in through the hose and into the interior of dust bag 26. If a nozzle or like cleaning implement II2 is secured to the end of hose 36 and passed over a dusty surface, dust will be drawn in with this air and deposited within the dust bag. The air will pass through the material of the dust bag into the inlet of the fan and be discharged from the fan and pass through the electric motor 38, thereby cooling the motor. The air is discharged through opening 48 at the rear of the motor and passes through members' 49 and 5| to within Ichannel 52. From here the air passes into space 60 formed in casting I9 and through openings 62 in wall' 22 into space 65. Unless the hose is screwed into opening 6|, valve member 66 closes this opening and no air escapes therethrough. From space 65the air passes into space 12 formed between casing I0 and inner casing 25. From here the air is discharged through louver openings 16 in a plurality of streams to the atmosphere.
It will thus be seen that the air has passed the entire length of the cleaner after having been discharged from the motor-fan unit, and then has its direction reversed and starts to pass to'- ward the rear of the cleaner before its passage to the atmosphere. This vcomparatively long path oftravel of the air causes the sound produced by the operation of the motor-fan unit, which sound This results in a much quieter operation of the cleaner than would be the case if the air were immediately discharged after having passed through the motor-fan unit. The corrugations in the bottom of channel 52 permit radiation of heat from the air which has been warmed by the motor, and thus prevent any possibility of overheating of the cleaner.
If it is desired to use the device for blowing purposes, hose 36 is screwed into opening 6|. The extension 10 on the hose presses valve member 6G, against the action of spring 68, to the position shown in Fig. l0, thus closing openings 62. When themotor-fan unit is operated air is drawn through opening 35, and passes as before described to space 60. From here the air passes directly into the hose and does not pass through openings 62 into space E5.
The operation of the dust indicator will now be described.
The dust bag always offers some resistance to the passage of air therethrough, and hence the pressure existing within inner casing 25 and outside of the dust bag is lower than the pressure existing within the dust bag.v As dirt accumulates within the bag this adds to the resistance to flow, and hence the pressure drop through the bag is an indication of the amount of dirt contained therein. The low pressure outside of the bag is communicated through openings 19 to the lower side of diaphragm 88. As before described, the pressure existing within the bag is communicated to the upper side of the diaphragm. As dirt accumulates within the bag, this causes an increase in the difference in pressure, and hence there is a greater pressure difference acting on the diaphragm. Inasmuch as the higher pressure exists within the bag and hence on the top of the diaphragm, the diaphragm is caused to move downwardly against the action of spring 95. This causes the upper end of rivet 9| to be moved away from part 92 of the indicator member 8|, and weight 81 is able to cause the indicator mem- `lier to rotate slightly in a clockwise direction. The amount of this rotation is visible through opening 86 and when it is suillcient the operator knows that the dust bag should be removed and emptied.
In order to remove the dust bag it is only necessary to unfasten clips 32 and remove cap 3|. This may be done without standing the cleaner on end inasmuch as theopen end of the bag is in an inclined position and the dirt contained therein will not fall out when the cap Il is removed. The bag may be withdrawn through opening 20 in the casting I! and emptied. In replacing the bag it is preferable to start the motor-fan unit, and the suction thus produced will draw the bag into place within the cleaner. The air flow carries the closed end of the bag to the right, as viewed in Fig. 5, until it strikes the closed end of cage 21. Thereafter, the difference in pressure inside and outside the bag tends to inflate it to the greatest possible extent and hence tends to straighten out the bag adjacent to the open end thereof where it is somewhat curved due to ring 28 being in an inclined position. This tendency to straighten out the bag prevents the formation of folds at this point, and the folding occurs further back toward the closed end of the bag. i
While I have shown one more or less specic embodiment of my invention, it is to be understood that this has been done for purposes of illustration only and does not constitute a limitation. The scope of the invention is to be determined by the appended claims viewed in the light of the prior art.
What I claim is:
i. A casing for a vacuum cleaner including a front member, a lower shell, an upper shell, said front member being formed with an inlet opening and an outlet opening, means, for securing said shells together and to said front member, a dust bag in said casing, said front member having an inclined wall formed with an opening, means for securing the open end of said dust bag in said opening, said lower shell having runners for movably supporting said casing on a surface, a flexible hose, and means for connecting an end of said hose to said opening, said hose being adapted for pulling said casing around on said surface.
2. In a vacuum cleaner, a casing including a lower shell portion and an upper shell portion, a frame member extending upwardly from the side of said lower shell and within said casing, a motorfan unit supported by said frame within said casing, and means for securing said upper shell to said frame whereby said shells are held in xed relationship.
3. In a vacuum cleaner, a casing formed with a horizontally extending space for a dust bag, a dust bag formed with an open end and having a length greater than the length of said space, and means for securing the open end of said bag in a position inclined with respect to the lengthwise extent of said space, whereby the axis of the bag is curved adjacent to said open end.
4. In a vacuum cleaner, a casing arranged to be supported horizontally on a substantially horizontal surface and formed with an opening in a plane inclined to the horizontal, said opening communicating with a space within said casing having a horizontal lengthwise extent, a dust bag in said space having a length greater than that of the space, said dust bag having an open end, and means for removably securing said open end adjacent to said inclined opening in said casing, whereby the axis of the bag is curved adjacent to said open end.
5. A vacuum cleaner including a casing having a horizontal longitudinal extent when normally mounted on a horizontal surface, said casing having an opening at one end in an inclined plane, a dust bag having an open mouth securable in said opening and normally extending longitudinally of the casing, said dust bag being supported in said casing along the bottom so that the center-lineA of the bag is bent adjacent to the mouth thereof, a cover for securing said bag at said inclined opening, and surface contact means on said casing whereby the casing may be pulled in the line of longitudinal extent.
6. A vacuum cleaner including a casing having a horizontal longitudinal extent when normally mounted on a horizontal surface, said casing having an opening at one end in an inclined plane, a generally cylindrical dust bag having an open mouth securable in said inclined opening and normally having its axis extending longitudinally of the casing, said dust bag being supported in the casing along the bottom so that the axis of the bag is curved adjacent to the mouth thereof, a cover for securing the mouth of the bag in the inclined opening, and a hose connectible to said cover for 'delivering dust-laden air to said bag and for pulling the casing in the direction of its longitudinal extent.
7. In. a vacuum cleaner, a casing, partition means dividing said casing into a rst chamber, a
second chamber and a third chamber, said casing being formed/with an inlet opening at one end thereof communicating with one end of said iirst chamber, and with an outlet opening at the same end communicating with one end of said second chamber, the other ends of said ilrst and second chambers being in communication, said casing being formed with a plurality of outlet openings communicatingwith said third chamber, said partition means being formed with a passage between said second and third chambers adjacent the first mentioned outlet, means for producing iiow of air through said casing, and valve means for closing said ilrst mentioned outlet and opening said passage and alternatively for opening said rst mentioned outlet and closing said passage.
8. In a vacuum cleaner, an elongated casing formed of an upper shell member and a lower shell member, both of said shells having substantially at portions, means for joiningl said shells in air tight relation, a motor-fan unit for creating a pressure in said casing different from atmospheric, and reenforcing means in contact with the interior of said shells serving to stiflen said shells, and particularly ilat portions thereof, against deformation by said pressure differences. f
9. Apparatus as claimed in claim 8 characterized by the fact that said motor-fan unit is supported from said reenforcing means.
10. A non-circular, elongated casing for a vac-y uum cleaner of thev type designed to be pulled horizontally on a supporting surface by a hose including an upper elongated shell, a lower elon gated shell, said shells having attened portions and being joined together along lines in a plane disposed parallel to said supporting surface, a dust separating member within said casing, and means for supporting air-flow producing means within said casing, l V
11. In a. vacuum cleaner, an elongated casing, means for supporting said casing horizontally on a horizontal surface, said casing including at least two shells having flattened portions and open ends, said shells being Joined together in air-tight relation along linesin a plane disposed parallel to the lengthwise extent. of saidcasing, an end member formed with a dust bag opening, means for securing both of said shells to said end member, a dust bag securable in said dust bag opening, andl means for supporting air-flow producing means within said shells.
12. In -a vacuum cleaner, an elongated casin having a substantially fiat portion, a motor fan within and in contact with the interior of said casing serving to stiifen said casing, and particularly the flat portion thereof, against deformation diierences.-
by said pressure GUSTAF EINAR LOFGREN.