US2641333A

US2641333A - Suction cleaner

Info

Publication number: US2641333A
Application number: US221666A
Authority: US
Inventors: William H Woessner
Original assignee: Hoover Co
Current assignee: Hoover Co
Priority date: 1951-04-18
Filing date: 1951-04-18
Publication date: 1953-06-09
Anticipated expiration: 1970-06-09
Also published as: GB703219A

Description

June 9, 1953 w. H. WOESSNER 2,641,333

SUCTION CLEANER Filed April 18, 1951 s Sheet-Sheet 1 IN VEN TOR.

WILLIAM H. WOESSNER ATT'Y June 9, 1953 w. H. WOESSNER 2,641,333

\ SUCTION CLEANER Filed April 18, 1951 6 Sheets-Sheet 2 mmvrom WILLIAM H. WOESSNER June 9, 1953 w. H. WOESSNER 2,641,333

SUCTION CLEANER Filed April 18, 1951 e Shets-Sheet 3 IN V EN TOR.

I LL-IAM H.WOESSNER ATT'Y June 9, 1953 w. H. WOESSNER 2,641,333

SUCTION CLEANER Filed April 18, 1951 6 Sheets-Sheet 4 mmvrox; WILLIAM H, WOESSNER ATT'Y June 9, 1953 w. H-. WOESSNER SUCTION CLEANER 6 Sheets-Sheet 5 Filed April 18, 1951 INVENTOR. WILLIAM H. WOESSNER @W ATT'Y' June 9, 1953 w. H. WOESSNER 2,641,333

SUCTION CLEANER filed April 18, 1951 6 Sheets-Sheet 6 INVENTOR. NILLIAM H.WOESSNER ATT'Y Patented June 9, 1953.

SUGTION CLEANER.:.

WillianrIL Woessnen, Canton, .0hio,.. assignor. to The..Hoover Company, NorthCanton, ()hio a...

corporation of' Ohio ApplitatiomAprihlS, 1951;. ,SeriaLIENOt. 221,366

241Cl'aims; (GL.183.--51)f The" present invention relates; to:suction cleans eessand more particularly;- to va filter. bagltherefor; and .to'themethod of :making: the same.

Specifically; the; inventionrelates to. inexpen-v siyegzporouspaper filter. bags which are-intended to be discarded and replaced by new: onesiafter becoming soiled by zuseo Thepfilter bags, of; the present=.invention:are=;for-. attachment to (the .exhausts-nozzle; ofan, upright type,- cleaner; and arecintendeditozbe protected by an air; pervious cloth. bag which does not act: as. a filterebut merely-permits. passage ;.of-. clean air; filtered" by the encased porous paper 1' filter bags.

The porous paper bag .to:whichthe-dnvention relates; when expandedtis:QfJarge diameter/oyer tlrea maj orportiorriof itsslength' to: providea large filtering; area; At;its; ;lower-. end,;howe.ver; it must-,fitt; closely: about: the: exhaust 1 nozzle of l a suction: cleaner: which; hasa; comparatively smaller diameter:

For r that: reason the bagrzisaproyided with in; wardly extending: accordion: like: f older. or: pleats over its entire length'and; may be'formediin a well"kncwmbag:making-machine: The-diameter ot the open lowerropen.end ofztheabagzwithycers tain folds turned? inwardly and: sealed, is sub; stantially the same as thatioffthesexhaust nozzle of the cleanera to which it 1151130: bezzattached.

The-lower open endi'of the porous paper-shag must be clamped to' the'exhausttnozzleof, fa suc.=.= ti'on cleaner; and' inorder' to prevent failure when expanded, the lower folded-endfofthe bag: should be reenforced and properly positionedperiphorally.

It* is also necessary to' provide-some means; for preventing-dust anddirtwhich is blown upwards ly intothe bag and separated "from therair; from falling backwardl'y' into the exhaust nozzle: of the-"cleaner.-

It is' knownin the art to attach the lower end ofa rigid tubeto the inner lowenopenen'd-"of the bag' neckand extend the tube-upwardly into the bag to form a trap aboutits periph'eryvas the" bag is expanded by air pressure during use.

Difii'culty has been experienced in attaching both'thereenforcement and the dirttrapr tube to the foldedlower end of the bagon .account of thefolds in the bag;

Prior to' the present invention it was; usual practice to sew or stitch both the-reinforcement'and the dirt'trap to'thefolded lower endof the bag which required separatelyholding'both oftliese items during the-sewing operation and sewing across the folds of the bag asthe seam was" made about the "periphery of the folded-and 2. narrowed end thereof while thereenforcement and a dirt .trap were. held, in, place on .the. inner and :outer sides of thefolded .open bagsendn According to the present: invention the; re: enforcementand .dirt traparemade of a, single blanlc of acomparatively stiifipaper, impregnated with a cement which. may be thermosetting so that both the reenforcement 'andthedirtl-trap maypbev. appliedto the lower folded open. end of thehpaper. bag by: aosimplel operation.

The blank is cut and scored'to form the proper panels, flaps andltabs. The. blank iathen folded along, longitudinalscoring; lines. and. the free edgessecuredtogether to. form. a..double\ layer sleeve. whichmay, be expanded. into" a, circle by pressing inwardly. on .the... edges.- thereof.

The flat lend whicheventually. forms .the dirt trap, is inserted into the flat open endliofl the pprouspaper bag insideopposedfolds with a locatingnotch formed in. the reenforcement'and positioned; at the edge of. the material. of the open end,of .'the..bag.. Thevarious flaps and tabs aresthen .fdldedibackwardly over the outside of thefolded open end of-the bag,,two of the flaps or tabs bfeing folded inwardly from the. outside. to overlap. the interior, of..the\ folds resulting in a construction .-.in. which. theupper and lower folds of the bag are. permanently. sealedagainst .unfolding movement. while. the central foldsvare free to ibeuexpandedrto form. a circular, neck .of, a diameter; tol fitztheexhaust nozzle of. theolaner.

The open end.of.the-.bag and. they combined reenforcement, and... dirt trap iscrthenlexpanded andtelescopedtoverlalheated.form of substantial- 1y the-same diameteras the. exhaust nczzleof theccleaner. Heating shoesare ,then applied over theexterior. periphery of. theassembly to heat sealthematerial ofthereenforcement andtrap to .the. interior and exterior. of the bag neck, it being v noted that .the.,material ofthe reenforcementsis. sealed... interiorly, and exteriorlyof. certainafolds: of .thebag andextend across .the fold"; ed edges thereof so astolockthe unoccupied folds againstexpansion at the lowerlopenendof the. bag and .thus formabag. neck which whenv expanded is of; substantially thesame. diameter. as that. of theexhaustnozzle to whichit is. tobeapplied and which may be easily telescoped over, the exhaust nozzle .with a. positioningv notch. mating with a complementary detent'on the exhaustnozzle. H

The patentto Smellie- 2,418,371; dated=April 1; 1947', proposed to=eliminate the necessity of separately sewing the dirt trap and; reenforcings'memberx-to. the mouth' of "the-bag. However, accordi'ngsto the teaching-of that patent .itisnem 3 essary to separately secure the unoccupied folds to each other prior to the application of the dirt trap and then to separately secure the dirt trap and reenforcement to the bag mouth.

The present invention is an improvement over the Smellie construction in that it eliminates the necessity of separately securing the unoccupied folds to each other while retaining the function of the separate securing means.

Other objects and advantages of the present invention will become apparent as the description proceeds when taken in connection with the accompanying drawings in which:

Figure l is a view of the blank of one form of the combined neck reenforcement and dirt trap of the present invention, the heavy single lines denoting cuts through the material and the light double lines denoting score or fold lines;

Figure 2 shows the blank of Fig. 1 applied to the open end of the filter bag preparatory to the 'heat sealing operation;

Fig. 5 is a perspective view of the invention of Fig. 1 in the final stages of the folding operation;

Figure 6 is a perspective view of a preferable heat sealing apparatus as the dirt valve and positioning reenforcement is being heat sealed;

Figure '7 shows the second modification folded preparatory to the heat sealing operation; and

Figure 8 shows the blank for the second modification.

Referring to the drawings, the porous filter bag is generally indicated by the reference numeral l0. It is formed by a bag forming machine in a manner well known in the art and is adapted to be enclosed in a protecting pervious cloth bag as disclosed in the United States patent to Smellie 2,418,371, dated April 1, 1947.

As shown in Fig. 4 the bag I0 is folded so as to have on each side three outwardly extending reentrant or accordion-like folds H, l2 and I3 and .two inwardly extending reentrant or accordion-like folds 4 and I5 extending the full length thereof. The open end of the bag I0 is cut in a shallow V-shape as shown at |6.

The reenforcing and valve element comprises a valve portion I1 and a reenforcing portion 8. The blank of the first modification is shown in Fig. 1. The reenforcing portion |8 comprises a central reenforcing extension !9, side reenforcing extensions 20, intermediate flaps 2|, connecting tabs 22 and locking tabs 23. The valve portion I! comprises a central panel 24 and

side panels

25 and 26. The side panel 25 is provided with an extension 21 shown separated therefrom by a dash line as shown in Fig. 1.

The extension l9 and panel 24 are connected .by a fold line. 28 and at their central junction are secured to panels 25 and 26'by fold lines 4 as shown. The

panels

25 and 26 are connected to panel 24 by fold lines 36.

The blank of Fig. 1 is stamped from the rolls or sheets of paper preferably impregnated with a heat scalable cement of any suitable character.

Assembly of the modification of Figs. 1 to 5, inc.

The blank of Fig. 1 is manually manipulated and the

panels

25 and 26 folded over the panel 24, about fold lines 36, with the extension 21 of panel 25 overlapping the free edge of panel 26. If desired, the extension 21 may be sealed to the panel 26 in any suitable manner. The

tabs

22 and 23 and flaps 2| are spread outwardly as shown in Fig. 4 which leaves the spaces 31 in the top edge of the panel 24, which openings were formerly occupied by the locking tabs 23.

The folds of the open end of the bag Ill are then separated as shown in Fig. 4 and theflat valve or dirt trap portion inserted so as to occupy a position between mating folds, preferably the middle folds l2. The insertion is continued until the edge of the opening 29 is located at the apex of the V-shaped end I6 of bag M as shown in Fig. 2.

The open end of the bag ID is then collapsed and the extensions 20 turned rearwardly and underneath over the ends of folds l3 and I5 so that the edges of extensions 20 will overlap, as shown in dotted lines 38 of Fig. 2, to leave the flaps 2| and the

tabs

22 and 23 extending sidewardly from the edges of the bag 0. That will lock the folds l3 and I5 together.

The flaps 2| are then turned toward each other along lines 30 across the edges of the bag It] to overlap folds l2 and I3 with the flaps 2| lying over the material of the upper side of bag l0 above the openings 3'! in the panel 24 so as to reenforce the bag mouth at those'points. The tabs 22 will form a continuation of extensions 20 and will lie on the opposite side of the bag mouth from the flaps 2|.

The locking tabs 23 are then turned inwardly across the edge of the folds of the bag mouth and will occupy the openings 31 which they originally occupied as shown in Fig. 3. The extension I9 is then turned backwardly over the V- shape end l6 of the bag mouth. The locking tabs 23 and the extension I9 lock the folds II and I4 while the junction between the flap 2| and tab 22 also look the folds l2 and |3 across the edges of the bag I0.

The material of the flaps, extensions, tabsand panels, positioned as above described, are then heat-sealed to the material of the bag mouth both inside and outside in any suitable manner, but preferably by the apparatus shown in Fig. 6. The heat sealing operation will permanently lock the folds of the bag together, permanently attach the dirt trap I! to the inside of the bag mouth and reenforce the bag mouth both inside and outside.

The bag mouth is then ready for application to an exhaust nozzle of a suction cleaner similar to that shown in the United States patent to White 2,295,981, dated September 15, 1942. The notch formed by the opening 29 corresponds to the notch shown in the White patent.

The mechanism of the apparatus of Fig. 6 is mounted on a suitable support 50. A mandrel '5| projects forwardly from the support and is surrounded by four heating shoes 52 innerleaved ,at 53 so as to form a complete annulus when in closed position. The heating shoes are reciprotending apex.

form a continuation of lines 66 and 69.

the folds l3 and i5 of the bag.

.cated inwardly and outwardly by'air cylinders 54 controlled by a suitable valve mechanism operated in any suitable manner.

The mandrel 5| and the shoes 52 are heate by electric heaters to approximately 250 F. and

controlled by a timer which applies heat'for approximately 11 seconds. The timer may also "control the valve mechanism for reciprocating the shoes 52.

In operation the mouth'of the bag is expanded as shown in Fig. 3, its open end slidover the on both the inside and outside.

In the modification of Figs. 7 and 8 thecom- 'bined valve and reenforcement comprises a valve portion 56 and a reenforcing portion 6|. The valve portion 60 comprises a central panel 62 and side panels 63 connected to the central panel 62 by fold lines 64. Central reenforcing'extensions 65 and 66 are separated from each other by a out line 6'. and are attached to the central panel 62 by

diagonal fold lines

68 and 69 respectively, which meet substantially centrally of the central panel 62 to form an outwardly ex-- Side reenforcing flaps Ill are connected to the side panels 63 by fold lines H which Circular openings 12 are formed in the blank on the meeting line H adjacent the edges of side panels 63 and side flaps M as shown in Fig. 8.

A suitable glue or cement which may be'pressure sensitive, heat scalable or of any other kind is applied to one face of the material'of the blank 3 above the dot-dash line 73 of Fig. 8'. The material of the blank may be impregnated with a heat scalable cement as in the first modification.

Assembly ofFz'gs. 7 and 8 The side panel 63 is folded over on top of the panels 62 along the fold lines 64 so as to overlap as shown at M of Fig. 7. If desired, the overlapping portions M may be glued or cemented to each other in any suitable manner.

The mouth of the bag ill is then opened as shown in Fig. 4 and the valve portion '50 inserted between mating folds, preferably the central folds l2, until the edge of the openings 12 "mates with the V-shaped edge 56 of the bag mouth as shown in Fig. 7. The central extensions'65 and 66 are then folded backwardly and downwardly over the bag mouth so as to overlap as shown at of Fig. '7. which will lock The side extensions 70 are then turned backwardly and upwardly over the edge of the bag mouth so as to "overlap as shown at T6 in Fig. '7, it being noted that the openings 12 will mate to form a semicircular notch in the edge of the bag mouth. The side flaps 10 will thus lock the upperfolds H and M.

The glue or cement may then be activated in any suitable manner. If it is heat scalable the machine of Fig. 6 may be used as previously described. If the cement is pressure sensitive pressure may be applied either by the machine of Fig. 6 without using heat or in any other suitable manner.

According to both modifications, both the upper folds II and M and the lower folds l3 and i5 are permanently sealed to each other leaving the folds I2 free to expand to form the bag mouth and that, without the use of sepa- 6 rate means'ifor securing the unoccupiedfolds to- Eether.

While I have shown and described "but two modifications of myinventionit is to be understood that those modifications are to be taken as illustrative only and not in a limiting sense. I do not wish to be limited to the particular structure or method shown and described but to include all equivalent variations thereof except as limited by the scope of theclaims.

I claim:

L'The method of making a filter bag comprising the steps of, stamping a blank from" paper impregnated with a heat scalable cement, said blank being straight at one end and having reenforcing extensions connected to its other end by fold lines, folding saidblank into the form of a flat sleeve with reenforcing extensions extending from each flat side thereof, inserting the straight end of said sleeve between opposed folds of a tube of filter material having accordionlike folds extending inwardly from its opposed sides and two unfolded sides with the edges of said sleeve lying between the apices of the opposed folds, folding said reenforcing extensions across the ends of said folds to lie against the opposed unfolded'siclcs of said tube and applyingheat to the inner surface of'said sleeve and'to the outer surface of said extensions to bond said sleeve to the inner surface of said folds and to bond said extension to the outer surface of the unfolded sides of said tube.

2. The method of making a filter bag comprising: forming an open ended tube of filter material folded along its opposite sides to form a pair of central opposed outwardly extending reentrant folds,'and a pair of flat unfolded sides which cooperate with said central folds to form pairs of outer opposed outwardly extendingreentrant folds with the apices of said folds extending along the edges of the unfolded sides and ith the walls of said folds on each edge of said tube superimposed upon each other and upon the unfolded sides; forming a flat sleeve having integral extensions formed on both sides at one end;

inserting the free end of said sleeve into said central opposed folds with its edges positioned within the apices thereof; folding said extensions across the ends of said folds to lie against the 'unfolded sides of said tube and securing said sleeve to the walls of said central folds and said extensions to the unfolded sides of said tube.

'3. The method of making a filter bag comprising, forming a flat open ended folded tube of filtering material folded along its opposed sides to form a plurality of opposed outwardly extending reentrant folds and opposed unfolded sides with the aplces'of said folds extending along the edges of the unfolded sides'and with the walls of said foldssuperimposed upon each other and upon the unfolded-sides at each edge of said tube, cutting said folds and the unfolded sides at the open end of saidtube to form a shallow reentrant V-shapcd end, forming a flatten d tubular sleeve having integral extensions on both sides anda locating notch formed centrally on its one side at one end of said sleeve, inserting the unextended end of said sleeve into one'pair of said opposed folds with its edges lying within-the apices of said folds and the inner edge of said'locating'notch positioned at the apex of the shallow reentrant v-shaped end of the tube, folding said extensions across the ends of said folds to lie against the unfolded sides of said tube and securing saidextensions to saidunfolded sides and said sleeve -to 'thewalls of thefolds m which it ls-positioned.

4. The method of making a filter bag compris ing, forming an open ended tube from filtering material, folding said tube along two of its opposed sides to form a plurality of opposed outwardly extending reentrant folds and opposed unfolded flat sides with the outer apices of said folds extending along the edges of the unfolded sides and with the walls of said folds superimposed upon each other and upon the unfolded sides of said tube at each edge thereof, forming a flattened sleeve having integral extensions on each side at one end inserting the unextended end of said sleeve into one pair of said opposed folds with its edges lying within the apices of said folds, folding said extensions over the ends of said folds to lie against the outer surface of the unfolded sides of said tube at its open end, bonding said sleeve to the inner surface of the folds in which it is positioned and bonding said extensions to the outer surface of the unfolded sides of said tube.

5. The method of making a filter bag comprising, folding an open ended tube of filtering material along two of its opposed sides to form a plurality of mating outward extending accordion-like folds and opposed flat unfolded sides with the outer apices of said folds extending along the outer edges of the unfolded sides and with the walls of said tube superimposed upon each other and upon the unfolded sides of said tube at each edge thereof, forming a flattened mouth and dirt trap forming sleeve from paper impregnated with a heat scalable cement, said sleeve having integral extensions on each side at one end thereof, inserting the unextended end of said sleeve into one pair of said opposed folds with its edges positioned within the apices of said folds, folding said extensions over the end of said folds to lie against the outer surface of the unfolded sides of said tube and applying heat to the inner surface of said sleeve and to the outer surface of said extensions to heat seal them to the open end of said folded tube.

6. The method of making a filter bag comprising: forming a blank from a sheet of paper im;- pregnated with a heat sealable cement and having a dirt trap and bag mouth forming portion and a reenforcing portion; said trap forming portion including a central panel and a side panel hinged to each side edge of said central panel; said reenforcing portion including a central extension hinged to said central panel, a side extension hinged to each of said side panels on a diagonal fold line sloping toward said central panel, a flap hinged to the inner edge of each of said side extensions by a diagonal fold line and a locking tab hinged to the lower side of each of said flaps by fold lines forming a continuation of the fold lines for said side extensions and being cut from the material of said central panel; folding said side panels over said central panel so that their edges overlap; bonding the overlapping edges to each other; inserting said folded trap forming portion into the central fold of a flattened open end filter bag having accordionlike folds in its opposed edges; folding said central extension across the ends of said folds to lie against one of the unfolded sides of the bag; folding said side extensions across the ends of said folds to lie against the other unfolded side of said bag; folding said flaps across the folded edges of the bag to lie against the first unfolded side of the bag on either side of said central extension; folding said locking tabs across the ends of said 'fold to lie against the interior of the-centralfold of the bag and applying heat to bond said panels. extensions, flaps and tabs to the surface of the bag where they contact therewith.

7. The method of making a filter bag comprising; forming a blank from a sheet of paper having a dirt trap forming portion and a reenforcing portion; said trap forming portion including a central panel and a side panel hinged toeach side edge thereof; said reenforcing portionincluding a side extension hinged to one end of each of said panels on a diagonal fold line sloping away from said central panel, a pair of central extensions hinged to said central panel on fold lines forming extensions of the fold lines of said side extensions, said central extensions being separated by a out line extending diagonally sideward from the junction of their fold lines; folding said side panels over on said central panel so that their edges overlap; bonding said overlapping edges to each other; inserting the folded trap forming portion into the central folds of a flattened open ended filter bag having accordion-like folds in each of the opposite edges thereof; folding said central extensions across the ends of the folds to lie against one unfolded side of said bag; folding said side extensions across the ends of the folds to lie against the other unfolded side of the bag and bonding said panels and extensions to the surface of the bag where they contact therewith.

8. In a suction cleaner, an open ended filter bag folded along two of its opposed sides to form a plurality of opposed mating outwardly extending accordion-like folds and opposed flat unfolded sides with the outer apices of said folds extending along the edges of the unfolded sides and the walls of said folds being superposed upon each other and upon the walls forming the unfolded sides of said bag at each edge thereof, the material of said folds and flat sides being cut to form a shallow reentrant V-shaped open end for said bag, a flattened mouth forming sleeve positioned within one pair of said opposed I folds with its edges extending to the outer apices of said folds, integral extensions on each side of said sleeve, said extensions being folded across stantially at the apex of the V-shaped open end of said bag, said sleeve and extension be- .ing impregnated with a heat scalable cement, said sleeve being heat sealed to the inner sides ,of the folds in which it is positioned and said extensions being heat sealed to the outer surfaces of the unfolded sides of said bag.

9. In a suction cleaner, an open ended filter bag foldedalong opposite sides to form a plurality'of opposed pairs of outwardly extending reentrant folds and opposed fiatunfolded sides with the outer apices of said folds extending along the edges of said flat sides with the walls of said folds being superposed on each other and upon the walls forming said flat sides at each edge of said bag, a flattened tubular sleeve positioned between the walls of one pair of said opposed reentrant folds with its edges extending to the apices thereof, extensions integral with each side of said flattened tubular sleeve, said extensions extending across the ends of said folds and the unifolded sides at the open end of said bag to lie against the outer surface of said unfolded sides, the walls of said sleeve be.-

ing bonded to the walls of the folds in which it is positioned and said extensions being bondedsaid opposed outwardly extending reentrant folds,

integral extensions on each side of said tubular member extending across the ends of the walls of said reentrant folds and lying against the unfolded sides of saidbag, said flat tubular member being bonded to the inside of the walls of the reentrant folds in which it is positioned and said extensions being bonded to the-outside of the unfolded sides of said big thereby locking" the walls of the remainder of said reentrant folds to each other and constituting the-sole means for preventing their expansion. I

11. In a suction cleaner, an open ended paper filter bag folded along its length'to form three opposed pairs of outwardly extending reentrant folds lying between two unfolded sides at each edgethereof whereby it can beflattened with the walls of the reentrant folds superimposed upon each other and upon the unfolded sides of. the 1 bag, a flattened tube having its edges. extending into one pair of opposed reentrant folds, integral extensions on both sides of said flattened tube extending across the ends of the Walls of said reentrant folds and lying against the unfolded sides of said bag, said flattened tube being secured to the walls of said reentrant folds; in which, it is positioned and said extension being secured to the unfolded sides of said bag, said tube and extensions forming sole connection between the walls of said reentrant folds.

12. In a suction cleaner, an open ended paper filter bag folded along its length to form three outwardly extending reentrant folds. and two in-. wardly extending reentrant folds on' each side so that the bag will lie flat with the walls of. said: reentrant folds superimposed, a combined dirt trap and reenforcing member associated with the Opel-fend; of said bag; said member having: anattened tubular portion positioned: between the Walls oflone pair of said outwardly extending re: entrant folds and integral extensions formed on one end of both sides of said flattened tubular portion, said extensions being folded over the ends of the walls of said reentrant folds so as to lie against the unfolded sides of' said bag and means for securing said tubular portion to the inner sides of the Walls of the reentrant folds in which it is positioned and for securing said extensions to the unfolded sides of said bag, said folded over extensions forming the sole securing means between the walls of said reentrant folds.

13. In a suction cleaner, an open ended filter bag folded along two of its opposed sides to form a plurality of opposed mating outwardly extending accordion-like folds and opposed fiat unfolded sides with the outer apices of said folds extending along the edges of the unfolded sides with the walls forming said folds being superposed upon each other and upon the walls forming the unfolded sides of said bag at each edge thereof, a flattened tubular sleeve positioned within one pair of said opposed mating folds with its edges extending to the apices thereof, the remainder of said folds remaining unoccupied, ex-

10 tensions integral with each side of said flattened. sleeve,v said extensions extending across the: ends of the walls of both the occupied andunoccupied folds and lying: against the outer surface of the walls forming the unfolded side of, said bag, thesides of said sleeve being bonded to the inside of thewalls'of thefolds in which it is positioned? and said: extensionsbeing bonded to the unfolded sides; of saidbag, said sleeve and extensions form.-

ing the sole means for holding the unoccupied foldsfromexpanding.

14:. Ina suction cleaner, an. open ended filter bag folded. along. two of. its opposed sides to form three.- opposed mating outwardly extending ac cordion1ike folds-and opposed flat unfolded sides with the outer apices of said folds extending. along the edges of the unfolded sides andwith. the walls of said folds being superimposed upon each other and upon the fiat unfolded sides at.

each edge of said bag, a flattened tubular mouth forming sleeve positioned withinthe central: pair, of said opposed folds with its edges' extending. to the apices of said central folds, extensions inte-- gral with each side of said sleeve, said extensions extending across the ends of the foldson opposite sides of said central folds and lyingagainst the outer surface of the unfolded sides of said bag, said sleeve and extensions being impregnated with a heat scalable cement, said sleeve being heat sealed to the-inner surface of. said cen tral folds and said extensions being heat sealed to the outer surface of the unfolded sides of said: bag.

15. In a suction cleaner, an open ended filter bag folded along two of its opposed sides to form a plurality of opposed mating outwardly extending accordion-like folds and opposed flat unfolded sides with the: outer apices of said folds extending. along the edges of. the unfolded sides and with the walls of said folds. being, superposed upon each other and upon the Walls fomring the unfolded sides ofv said bag. at. each edgethereof, the material of said folds andflat sides being cut to form a shallow reentrant V-shaped open end for said bag,-a flattened mouth formingsleeve positioned within one pair. of saidopposed folds withits edges extending to the outer apicesthereof, integral. extensions on each side of said sleeve, said. extensions being: folded across the ends of saidfolds to lie against the outer surface of said fiat unfolded sides, a locating notch formed. centrally in one side of said sleeve, the inward edge of said notch being: located substane tially at the apex of the V-shaped. open end of. said bag, said. sleeve being secured tothe inner surface of the folds in which it. is positioned andsaid. extension being secured to the outer sidesof said fiat unfolded sides.

16. In a suction cleaner according to claim' 15 in which the fold lines between the sides of said sleeve and said extensions form an outwardly extending V-shaped edge on one side of said sleeve and a reentrant edge on the other side thereof with said notch being located at the apex of said reentrant edge.

17. A blank for forming a dirt trap and reenforcement for a filter bag mouth comprising, a substantially rectangular central panel, a side panel hinged to each side edge of said central panel, the combined widths of said side panels being greater than the width of said central panel, a central extension hinged to the central portion of one end of said central panel on a fold line normal to the side edges of said central panel, a side extension hinged to one end of each side panel on diagonal hinge lines sloping toward the hinge line for said central extension, a flap hinged to the inner edge of each of said side extensions on fold lines forming continuations of the fold lines between said central and side panels so as to overlie said central panel, said flaps being separated from said central extension by a diagonal cut, and a locking tab hinged to the lower edge of each flap on hinge lines forming a continuation of the hinge lines between said side panels and side extensions, said locking tabs being cut from the material of said central panel.

18. A blank according to claim 17 in which a circular opening is cut centrally in said central panel and extension on the fold line between them to form a locating notch when the blank is folded about a bag mouth.

19. A blank for forming a dirt trap and reenforcement for attachment to a filter bag mouth comprising, a central substantially rectangular panel, a side panel hinged to each lateral edge of said central panel, the combined widths of said side panels being greater than the width of said central panel so as to overlap when folded over upon said central panel, a pair of extensions hinged to one end of said central panel on sloping hinge lines meeting at an outwardly extending apex centrally of said central panel, said central extensions being separated by a out line extending diagonally from said apex and a side extension hinged to each side panel on hinge lines forming extensions of the hinge lines between said central panel and central extensions.

' 20. A blank according to claim 19 including locating openings cut in each of said side panels and extensions on their fold lines adjacent their free edges so as to mate when said side panels are folded upon said central panels.

21. In a filter bag, a flattened trap forming sleeve positioned in the central folds of an open end flattened bag of filter paper having accordion-like folds extending inwardly from its opposite edges, a first reenforcing extension of less width than said flattened sleeve centrally attached to one side of said sleeve and extending across the folds on one side of the bag and lying against one of its fiat sides, second and third reenforcing extensions attached to the other side of said sleeve on diagonal fold lines meeting centrally of said other side of said sleeve to form an outwardly extending apex, said second and third extensions extending across the ends of the folds on the other side of the bag and lying against the other fiat side thereof, a reenforcing fiap attached to the outer edges of said second and third reenforcing extensions and extending across the edges of the bag at its open end and lying against the first mentioned flat side of the bag at opposite ends of said first reenforcing extension, and a locking tab attached to each flap and extending across the ends of the folds on the first mentioned side of the bag and lying against the interior surface of the central folds of the bag, said sleeve, extension, flaps and tabs being bonded to the surface of the bag walls with which they are in contact.

22. In a filter bag according to claim 21 in which the open end of said bag is cut to form a shallow reentrant V-shaped end and said first reenforcing extension and the first mentioned side of said sleeve are formed with an inwardly extending positioning notch having its inner edge positioned at the apex of said V-shaped end.

23. In a filter bag, a flattened trap forming sleeve positioned in the central folds of an open ended flattened bag of filter paper having accordion-like folds extending inwardly from its opposite edges, first and second reenforcing extensions attached to one side of said flattened sleeve on outwardly inclined fold lines meeting centrally of said one side to form an outwardly extending apex, said first and second extensions extending across the ends of the folds on one side of the bag and lying against one fiat side thereof adjacent said open end, third and fourth reenforcing extensions attached to the other side of said sleeve on fold lines inclined in the opposite direction from the first mentioned fold lines and meeting at a reentrant apex centrally of said other side of said sleeve, said third and fourth extensions extending across the folds on the other side of the bag and lying against the other fiat side thereof adjacent its open end, said sleeve and extensions being bonded to the surfaces of the walls of said bag with which they are in contact.

24. In a filter bag according to claim 23 in which the open end of said bag is cut to form a shallow reentrant V-shaped end and said third and fourth extensions and the second mentioned side of said sleeve are formed with an inwardly extending positioning notch having its inner edge positioned at the apex of said V-shaped end.

WILLIAM H. WOESSNER.

' References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,444,762 Waters July 6, 1948 2,488,038 Sharkey Nov. 15. 1949 2,564,845 Holt Aug. 21, 1951 2,566,275 White Aug. 28, 1951