US2804166A - Dust containers for vacuum cleaners - Google Patents

Description

Ailg- 1957 H. w. STEVENS ETAL 2,804,166

DUST CONTAINERS FOR VACUUM CLEANERS Filed May 11, 1953 3 Sheets-Sheet l Aug. 27, 1957 H. w. STEVENS ETAL 2,304,156

nus'r CONTAINERS EOR'VACUUM CLEANERS Filed May 11, 1953 I '3 Sheets-Sheet 2 INVENTORS HE/veY W. 576 Vin 6 Guam; t7/me .Lorszav EflYMO/VO 'L. BEOWA/ fie/V040 M 66505 ATTbRNEY Aug. 27, 1957 H. W. STEVENS ET AL DUST CONTAINERS FOR VACUUM CLEANERS 3 Sheets-Sheet 3 Filed May 11, 1953 Unite States Patent DUST CONTAINERS run VACUUM CLEANERS Henry W. Stevens, Phoenixville, Pa., and Gustaf Einar Lofgren, Riverside, Raymond L. Brown, Noroton Heights, and Arnold H. Beetle, fitamford, Conn, assignors to Electrolux Corporation, Cid Greenwich, Conn, a corporation of Delaware Application May 11, 1953, Serial No. 354,148

11 Claims. (Cl. 183-49) Our invention relates to disposable dust containers for vacuum cleaners. Containers of this nature may economically comprise a bag portion of porous paper secured to a disc of relatively stifi cardboard, as is disclosed in Patent No. 2,621,757 of Emil Anderson issued December 16, 1952.

The porous paper employed for the bag portion has a porosity such that it will permit the passage therethrough of air, but will retain dust and other particles of dirt. As the dirt accumulates within the bag it increases the resistance to air flow and consequently increases the pressure drop through the bag and the porous paper must have sufiicient strength to resist the bursting pressure resulting from this pressure drop. For a paper to possess this strength and to be able to filter out the fine particles of dirt, it is necessary that the interstices between the fibers be very small. Although satisfactory porosity of such a paper is obtainable by having a very large number of these interstices, nevertheless, due to their small size,

they become rather quickly clogged up by fine dust, thus increasing the pressure drop through the bag which in turn reduces the air flow and. the cleaning efiiciency of the vacuum cleaner. This condition particularly obtains in those regions where fine dust is the predominant constituent of the dirt picked up during operation of the vacuum cleaner.

In order to remove fine dust from the air it is desirable to provide what is termed a filter in depth. Such a filter should have rather large interstices and, While the fine particles of dust are small enough to pass through these interstices, the depth or thickness of the filtering material is such that most of the fine particles are caught before they get all the way through. However, such filtering material has very little mechanical strength and consequently would not be able to resist the bursting pressure. Moreover, it would not be suitable to use this material by itself, even if it could be made strong enough, inasmuch as a certain amount of fine dust will find its way through.

In accordance with our present invention we employ filtering material of this nature as a liner for an outer bag made of paper of the type first abovedescribed. With this combination the outer bag has suificient strength to withstand the bursting pressure and the interstices therethrough are small enough to retain the fine dust particles which find their way through the inner liner. On the other hand, the liner is able to remove most of the fine dust without becoming quickly clogged and the amount of fine dust which does reach the inner surface of the outer bag is so small that quick clogging of the latter does not result. Consequently, a dust container made in accordance with our invention is able to retain a much larger quantity of fine dust before the pressure drop becomes excessive, than have containers heretofore used.

In accordance with one embodiment of our invention the liner consists of a sheet of fibrous material, such as wadding of cotton, wool, cellulose, synthetic fibers or the like. This sheet is of comparatively open structure, but.

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for ease of handling it preferably is compressed, heat sealed, stapled or otherwise compacted together at spaced points or along spaced lines, or it may be a plurality of such sheets secured together in this manner.

In accordance with another embodiment of our invention a quantity of loose fibrous material, such as wool, cotton, synthetic fibers, cellulose or other springy fibers may be introduced into the container during its manufacture. When such a container is placed in a vacuum cleaner, the air flow therethrough tends to distribute the loose fibrous material more or less evenly over the inner surface of the bag, thus providing the desired filter in depth. Especially when loose material is placed in the container, it is-preferable that the inlet opening of the latter be provided with a self-closing seal in order that the loose fibrous material will not be spilled therefrom prior to placing the container in the vacuum cleaner, as well as to prevent the escape of dirt when the container is removed from the cleaner. The loose fibrous material may be used either with a bag having a liner as above described, or with a bag without such a liner.

In accordance with a still further embodiment of our invention loose fibrous material may be adhered to the inner surface of either the paper bag or the liner by'means of glue or the like, thus assuring that the fibrous material will be evently distributed over the inner surface of the container. Inasmuch as the glue or other adhesive tends to seal the interstices of the liner or outer bag, the entire inner surface should not be coated with glue, but the latter should be merely spotted over the surface. I

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

Fig. 1 is a side view, partially in cross section, showing a container in accordance with our invention in place within a vacuum cleaner;

Fig. 2 is a side view of the container shown in Fig. l, but in collapsed condition;

Fig. 3 is a top view of the container shown in Fig. 2, partially broken away;

Fig. 4 is a view partially in cross section of the container shown in the previous figures, but on a greatly enlarged scale in order to show the multi-layer construction of the liner;

Fig. Sis a view similar to Fig. 3, but showing the bag portion before the cardboard disc has been applied thereof Fig. 3;

Fig. 8 is a cross-sectional view taken on the same line as Fig. 7, but showing the bag in fully expanded condition;

Fig. 9 is a cross-sectional view on an enlarged scale taken on the line 99 of Fig. 6;

Fig. 10 is a cross-sectional view showing a container partially expanded and partially filled with loose fibrous material and is taken on the line 10-10 of Fig. 11;

Fig. 11 is a cross-sectional view taken on the line 11-11 of Fig. 10;

Fig. 12 is a cross-sectional view of the container shown in Figs. 10'and 11, but in fully expanded condition, and with the loose fibrous material distributed by the flow of air therethrough; and

Fig. 13 is a view similar to Fig. 12, but showing a container with loose fibrous material adhered to the inner walls of the bag portion.

Referring to the drawings, and more particularly to Fig. 1, reference character 10 designates generally a disposable container in accordance with our invention in place within a vacuum cleaner. The cleaner includes a"- housing 12 within which the container is disposed when in use. A motor fan unit 14 is mounted in one end of the housing, while the other end may be closed by a removable cover member. 16. The cover is provided with an inletconduit 18 which, when the, cover is in place, extends some distance into the housing 12. The outer end ofthe inlet conduit is provided with one element 20 ofa separable hose coupling, bymeans of .Which a flexible hose, may be connected to the inlet conduit. Operation of the fan serves to draw air and entrained dirt inwardly from the hose through the inlet conduit to within the container 10. The bag portion of this container is pervious with respect to air, but. impervious with respect to dust, and consequently the air passes through the walls of the bag-portion while the 'dust'is retained therein.

, The container comprises an outer bag portion having a first pair of side walls 22 'and 24 and a second pair ofside walls 26 and 28, all four of these walls being best shown in Fig. 9. The side walls 26 and 28, are formed with longitudinally extending center creases 30 and 32, respectively, whereby these walls may be folded fiat between the walls 22 and 24 when the container is in collapsed condition. This bag portion is made from an initially flat sheet of paper, the longitudinal edges of which are secured together by a seam 34 in the side wall 22. I When the bag is in expanded condition, as is shown in Figs. 1 and 8 the sidewalls. of each pair are disposed parallel to each other, while the side walls of the different pairs are disposed substantially at right angles to each other. I

The'left-hand ends of the side walls, as viewed for example in Fig. 5, are formed with extensions which, when the bag portion is in extended condition, extend inwardly at substantially right angles with respect to the side walls. Thus, the side walls 22 and 24 are formed with extensions 36 and 38, respectively, while the side walls 26 and 28 are formed with extensions 40 and 42, respectively. As will be seen particularly. in Fig. 5, the length ofeach extension is less than one-half the distance from the respective side Wall to the other side wallof the same pair, thus forming a rectangular opening 44 in the flat end portion of the bag.

Secured .to the flat end portion as by means of a suitable adhesive, is a flat relatively stiff disc 48 of cardboard, or the like having preferably a circular aperture 50 which communicates with the rectangular opening 44. Thus, aperture 50 and opening 44 together constitute an inlet aperture for the container, through which extends the inlet conduit 18 when the container is in place within the vacuum cleaner. r

Disposed within the outer bag portion of the container is a liner bag designated by reference character'52. This liner bag is preferably made of fibrous sheet materialhaving a much greater porosity than that of the outer bag. A suitable material for this purpose is cellulose waddi'ng which has larger interstices therethrough than has the porous paper of the outer bag. In order to obtain the desired thickness or depth of the liner a plurality of plies of'cellulose. may be used. Preferably these plies are laminated together by means of heat sealing, pressure or the like to provide a single sheet for ease in handling. As shown in Fig. 4, four plies are employed and these are pressedrtogether along spaced parallel lines 54. However, a different number of plies may be employed and they may be secured together otherwise thanal'ong lines. The area over which they are secured should be kept, at a minimum consistent with that required to laminate the plies together, inasmuch as this area of the" walls and end extensions'as is the outer bag. 'However,

as will be clear from Fig. 9, the sheet of material forming the liner bag is offet laterally from the sheet forming the outer bag so that the side seam 56 of the liner bag is offset with respect to the side seam 34 of the outer bag. This not only reduces the thickness of the composite bag at the seams, but it enables the overlappededges of the sheet forming the outer bag to be glued directly to gether, that is without the liner sheet being interposed between the overlapped edges of theouter sheet. 'As is also apparent from Fig. 9, the width of the liner sheet may be slightly less than that of the outer sheet, inasmuch as less overlap is required for the inner seam 56 than is desirable for the outer seam 34. This is so because the outer seam must sustain the bursting pressure, while the liner bag' is mechanically supported by the outer bag and therefore the liner seam 56 is subjected to little or no force tending to tear it apart.

As is shown in Fig. 5, the extensions 36and 38 overlie the extensions 40 and 42 and consequently when the end disc 48 is glued to these four extensions, portions of the extensions 36 and 38 will be disposed between the extensions 40 and 42 and the disc. Inasmuch as the liner bag has extensions corresponding to those of the outer bag, the extensions of the liner bag corresponding to extensions 40 and 42 willbe disposed between the extensions 40 and 42 and the extensions 36 and 38, re spectively, as is shown in Fig. 8. Therefore, the liner bag will be secured to the outer bag at the inlet end. Also, the glue used to form the seam 56 may penetrate the liner and adhere it to the outer bag along the line of this seam.

A bag of this type may be manufactured on automatic bag machines by feeding simultaneously thereto a web of porous paper for the outer bag and a web of laminated cellulose wadding for the liner, the two webs being offset laterally from each other by the amount necessary to provide the above desciibed lateral spacing of the seams.

The end of the bag portion opposite from the disc 48' is closed. by having the side walls folded over on themselves several timesand glued, as is shown at 58. Inasmuch as this end of the liner bag is included in the foli over, the two bags are secured together at their closed en s. j When a bag of the above type is placed in a vacuum cleaner and air bearing fine dirt is introduced through the conduit 18, a majority of the fine dirt is intercepted bythe liner. While the dirtparticles may be smaller than the interstices between the fibers of the material used to form the liner, only a small percentage of such particles will find their way through the several plies or layers due to the depth of the filter provided thereby. The small percentage which does find its way through will be intercepted by the porous paper of the outer bag. However, ifthe-liner were not present all of the tine dirt would immediately reach the surface of the outer bag and would quickly. clog up the small interstices between the fibers thereof. This in turn would rapidly increase the pressure drop through the bag and consequently would reduce the air flow, thus reducing the etliciency of the vacuum cleaner. However, with the liner present, only a small percentage of the fine dirt reaches the inner surface of the outer bag. The dirt which is retained by the liner does not clog up its interstices as'rapidly as it would. the smaller ones of the outer bag and consequently a bag of this type is able to collect a much greater quantity of fine dirt than is an unlined bag, while still maintaining equal .efiiciency of the vacuum cleaner. The material of the outer bag has suflicient mechanical strength to sustain the 'bursting pressure imposed thereon as a result of the pressure drop through both bags.

Due to the fact that the liner, especially when clean,

offers much less resistance to the flow of air than does the outer bag and is unattached to the outer bag except attheendsand possiblyalongthe seam 56, it could occur,

particularly if the dust container were placed'in thevac'-;

uum cleaner with the seam 56 on the bottom, that the initial flow of air would inflate the outer bag without inflating the inner bag if it were not for the fact that both bags are formed with inwardly folded side walls 30 and 32. As will be seen from Fig. 9, inflation of the outer bag causes these folded walls 30 and 32 to straighten out and in so doing they carry the corresponding folded walls of the liner along with them, thus assuring that both bags will be inflated together. Should the inner bag not expand with the outer one, portions thereof would not be supported by the outer bag and hence would tend to flutter in the air stream and in consequence thereof might be torn. Also, should a relatively heavy solid object, such as a stone, be carried into the container by the air stream while the inner bag were partially unsupported, it could easily rupture the latter.

A still greater filtering depth is obtained in the disposable container shown in Figs. 10 through 12. In this embodiment the container shown in previous figures is partially filled with loose fibrous material 60. This material may be introduced into the bag by means of an air stream directed through the inlet opening, or it may be introduced through the opposite end of the bag before the side walls are folded over and glued. The loose fibrous material employed may be of different types, but We have found that springy, fine, rough fibers, such as wool, cotton, cellulose, or synthetic fibers are advantageous.

In order to avoid spilling of the loose fibrous material,

from the bag through the inlet aperture 50 before the container is put in use in a vacuum cleaner, a self-sealing closure is preferably provided for the inlet, as is shown in Figs. 6, l and 11. A sheet of elastic material 62, such as sheet rubber is glued to the outer surface of disc 48 so as to cover the opening 50 therethrough. This sheet is formed with a normally small elongated opening 64 substantially centered with respect to the opening 50. A strip of light cardboard 66 is secured to the outer surface of the disc 48 and initially extends over the opening 64 and is provided with a weakened portion 68 adjacent to one edge of the opening 50. Preferably an outer disc 48:: of the same size and shape as the disc 43 is glued to the disc 48 over the elastic sheet 62 and the strip 66, as is shown in Fig. 10.

If the fibrous material is to be introduced through the inlet opening of the container, a conduit similar to the inlet conduit 18 is inserted through the opening 50. The insertion of this conduit breaks the strip 66 at the weakened portion 68 thereof and stretches the rubber sheet 62 so as to enlarge the normally small opening 64- sufficiently to receive the conduit. A measured quantity of the loose fibrous material is blown into the bag through the inlet conduit. Upon subsequent withdrawal of the conduit the aperture 64 in the rubber sheet returns to its normal small size and the end of strip 66 remains inserted therethrough so as to substantially close this aperture, thus preventing spilling of the loose fibrous material during handling of the bag before the latter is placed within a vacuum cleaner.

When the bag is placed in the cleaner and the motor fan unit started, the inflow of air through the conduit 18 expands the bag and distributes the loose fibrous material 60 in a more or less even layer, as is shown in Fig. 12, over the inner surface of the liner. This loose fibrous material has a substantially greater thickness or depth than the liner and hence is able to intercept and hold a large quantity of fine dust before becoming clogged up. Most of the fine dust which does eventually find its way through the loose material is caught by the liner and consequently very little fine dust ever reaches the inner surface of the'outerbag. Therefore, a bag of this type can hold a substantially greater quantity of fine dust before the pressure drop becomes sufiicient to materially reduce the efficiency of the cleaner, than can other types.

Obviously, the liner 52 could be omitted and reliance placed entirely on the loose fibrous material for intercept-. ing the fine dust before it reaches the inner surface of the outer bag. Instead of introducing the fibrous material loosely into a completed or partially completed container, and relying on the air flow produced by the vacuum cleaner forproperly distributing the fibrous materials, adhesive may be applied at spaced points to the inner surface of the bag and loose fibrous material, preferably directly as received. from a carding machine, may be blown into the fully expanded bag. Under these conditions the air stream will distribute the fibrous material quite evenly over the inner surface of the bag where it will be retained by the adhesive. Due to the fact that the adhesive tends to seal the interstices in the bag, it should not be placed in a continuous film thereover, but only at spaced points as above described. A bag in accordance with this embodiment of the invention is shown in Fig. 13, where the loose fibrous layer 70 is adhered to the inner surface of the liner bag by means of spots of adhesive 72. As was the case with the embodiment illustrated in Figs. 10 through 12, the liner bag may be omitted and the layer of loose fibrous material 70 may be adhered directly to the inner surface ofithe outer bag. Instead of introducing the fibrous material into a completed bag, it may be applied to the web of paper or liner before the latter is formed into'a bag. a

While we have shown several embodiments of our invention, it is to be understood that this has been done for purposes of illustration only and the scope of our invention is not to be limited thereby, but is to be deter-,

mined from the appended claims.

What we claim is:

1. A disposable dust container for a vacuum cleanerineluding a bag portion comprising an outer bag composed of pliable porous paper of porosity to permit the passage of air but to preclude the passage of dust particles therethrough and of sufiicient strength to resist the bursting pressure resulting from the pressure drop of the air passing therethrough, a liner bag within said outer bag composed of a plurality of sheets of pliable fibrous material secured to each other at spaced points to form a laminated sheet having greater porosity and thickness than said paper, each of said bags being open at one end and otherwise closed, and means for permanently securing said bags to each other at their open ends.

2. A disposable dust container for a vacuum cleaner including a bag portion comprising an outer bag composed of pliable porous sheet material of porosity to permit the passage of 'air but to preclude the passage of dust particles therethrough and of suflicient strength to resist the bursting pressure resulting from the pressure drop of the air passing therethrough, a liner bag within said outer bag composed of pliable sheet material having substantially greater porosity and thickness than the first-meme tioned sheet material, each of said bags being open at one end and otherwise closed, means for permanently securing said bags to each other at their open ends, and fibrous material loosely disposed within said liner bag and distributable by air flow to form a filtering layer on the inner surface of said liner bag.

3. A disposable dust container for a vacuum cleaner including a bag portion comprising an outer bag composed of pliable porous sheet material of porosity to permit the passage of air but to preclude the passage of dust particles therethrough and of sufiicient strength to resist the bursting pressure resulting from the pressure drop of the air passing therethrough, a liner bag within said outer bag composed of pliable sheet material having substantially greater porosity and thickness than the first-mentioned sheet material, each of said bags being open at one end andotherwise closed, means for permanently securing said bags to each other at their open ends, self-sealing means" for closing the opening at the ends of said bags, and fibrous material loosely disposed within said liner bag and retained therein by'said self-sealing means and dis tributable by air flow to form afiltering layer on the preclude the passage of vdust particlestherethrough,,said

bag portion having an opening at one endand being otherwise closed, self-sealing means for closing said opening, and fibrous materialloosely disposed within said bag portion and retained therein by said self-sealing means and distributable jby airflowto form a filtering'layer on the inner surface of sai'dfbagportion;

5. A disposable dust container for a vacuum cleaner including a bag portion comprisingjan outer bag composed of pliable porous paper of porosity to permit the passage of air but to .preclude the passage of dust particles therethrough and of sutficinet, strength to resist the bursting pressure resulting from the pressure drop of the air passing therethrough, a liner bag within said outer bag composed of pliable sheet material having substantially greater porosity and thickness than said paper, each of said bags being open at one end and otherwise closed, means for permanently securing said bags to each other at their open ends, and a coating of individual fibers secured to the inner surface of said liner bag.

6. A disposable dust container for a suction cleaner,

said container including a composite bag portion comprising an outer bag composed of pliable porous paper of porosity to permit the passage of air but to preclude the passage of dust particles 'therethrough and of sufficient strength to resist the bursting pressure resulting from the pressure drop of the air passing therethrough, and a liner bag Within said, outer bag composed of pliable sheet material having substantially greater porosity and thickness than said paper, said composite bag having two pairs of side walls, the walls of each pair being substantially parallel to each other and disposed substantially at right angles to the walls of the other pair when said composite bag is in inflated condition each of the walls of one of said pair being formed with a center, longitudinally extending crease line whereby the walls of the last-mentioned pair are folded flat between the walls of the other pair when the composite bag is in deflated condition, the paper and sheet material forming an extension at one end of each side wall and being folded inwardly substantially at right thereby prolonging the filtering effectiveness of -said con tainer and accordingly of the dust receptacle.

8. For use with a vacuum cleaner, adisposable dust receptacle designed to be discarded when it becomes filled comprising a container of sheet material of sufficient strength to withstand the pressure of air to which it is subjected, a liner for said container composed of a plurality of sheets of fibrous material secured to each other at spaced points and constructed to be externally reinforced and supported by said container, said liner and container each being composed of filtering material of porous texture and through the pores of which air is adapted to' pass, the pores of the liner being larger than the pores of the container so that coarse dust particles entrained with air are retained by the liner, the thickness of the liner being greater than the thickness of the container sothat a substantial amountof finedust particles is also retained thereby, and the remaining ,fine dust particles passing through the liner are retained by the container, whereby ,upon the .use of the dust receptacle in areas in which there are relatively fine as well as coarse dust particles a substantial amount of the time particles as well as substantially all of the coarse particles are filtered from the air by said liner thereby prolonging the filtering effectiveness of said-container and accordingly of the dust receptacle. I

9. A disposable dust container for vacuum cleaners comprising an outer support layer of strong porous sheet material capable of filtering dust particles from an air stream and a liner of substantially greater porosity than said support layer intimately associated therewith, said liner comprising a plurality of plies of cellulosic wadding, and a thin applique of fibers on at least one surface of a ply of said wadding.

, 10. A disposableldust container for vacuum cleaners comprising an outer bag of strong porous sheet material capable of filtering dust particles from an air stream passing therethrough and of sufficient strength to resist bursting under the pressures exerted by the air stream, and a multi-ply liner of substantially greater depth and porosity than said outer bag.

11. A disposable dust'container comprising an outer bag of fibrous sheet material of suflicient strength to withangles to the respective wall to form a fiatend portion,

said end portion having anopening .therethroughto the interior of said liner bag, and said paper and sheet material being secured together at said. end portion around said opening, inflation of said outer bag causing the folded side walls thereof to unfold and to assure unfolding of the corresponding folded side walls of said liner bag.

7. For use with a vacuum cleaner, a disposable dust receptacle designed to be discarded when it becomes filled comprising a container of sheet material of sufiicient strength to withstand the pressure of air to which it is subjected, a liner for said container constructed to be externally reinforced and supported by said container, said liner and container each being composed .of filtering material of porous texture and through the pores of which of the fine particles as well as substantially'all of the coarse particles are "filtered from the air by said liner stand the pressure of air exerted thereon during the operation of, the vacuum cleaner, and a liner for said bag comprising a plurality of plies of cellulosic wadding secured together at spaced points and disposed to be supported by said outer bag, said outer bag and liner each comprising porous material through which air can pass, with the pores in said liner being larger than the pores of said outer bag and the thickness of the liner being greater than the thickness of said outer bag.

References Cited in the file of this patent UNITED STATES PATENTS 754,053 Derham Mar. 8, 1904 1,148,501 Collins Aug. 3, 1915 1,535,800 Anderson Apr. 28, 1925 1,738,249 Jordahl Dec. 3, 1929 1,810,613 Keller June 16, 1931 1,821,824 Woodward Sept. 1, 1931 1,847,352 McClatchie Mar. 1, 1932 2,225,389 Osterdahl Dec. 17, 1940 2,324,231 Osterdahl July 13, 1943 2,564,845 Holt Aug. 21, 1951 2,596,808 Lofgren May 13, 1952 2,637,409 Turner et al. May 5, 1953 FOREIGN PATENTS 257,711 Great Britain Sept. 9, 1926 527,228 Great Britain Oct. 4, 1940

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