US2891716A - Valve bag with pasted end closure - Google Patents

Description

June 23, 1959 H. E. LEE

VALVE BAG wma PASTED END cLosuRE Filed March 9, 1956 JNVE'NTOR. H4 P/PVE LEE.

///l// l llllttll ZW//Mmhm United States- Patf O VALVE BAG WITH PAsrED END cLosUREl v Harry E. Lee, Pensacola, Fla., assignor to St. Regis Paper C0mpany, New York, N.Y., al corporation of, New

York Y v v r v This invention relates to valve bags of the type having an end closure formed of pasted flaps, that is to say, with an inturned corner flap at each corner and with overlying side flaps pasted` with respect to one"corner ap, and with a valve opening provided between the other corner flap and the overlying side aps." Such bags are formed of paper or the like sheet material which may sometimes be laminated with' other material to reinforce same orV to render same moisture-proof or .capable of resisting deterioration by reason of chemically active materials contained in the bag. Usually,.but not necessarily, the bags of this invention are formed of a plurality of plies of the sheet material.. f- Y -v It has ofter1.been.thelpraticey to ,insert a flexible sleeve or supplemental sheet 'inmth'e' valve'of such bags to extend inwardly beyond the valvetlip at thefinner end ofv the-corner.' ilap so that suchvsleeve or sheetwilllbe collapsed or` pressed bythe contents `of the'bag. ;wl1en filled up against the interior of the top of the bag for more securely closing thefvalvefaga'inst leakage and sifting out,of ythe contents. It basalso been the practice so to secure' such4 sleeve' or supplemental' sheet to th'e lvalve lip that the latter will be thrust up against the top of the bag along with the sheet or sleeve. Despite numerous different expedients of this nature which have been used to obtain more secure and dependable closing of such valves, it is possible for some material, particularly if of a granular nature, to sift out. While this can largely be overcome by providing an outwardly protruding sleeve adapted to be tucked into the Valve after filling the bag, yet such tuck-in type sleeves have to be carefully and manually tucked in by the workman who operates the automatic filling machine and this substantially reduces the speed and increases the cost of filling the bags.

With the present invention, the above difficulties are quite surprisingly and effectively overcome by using an inwardly directed valve sleeve so secured in place in the valve that in effect a pocket will be provided between the inner portions of the valve lip and portions of the sleeve material thereabove which are thrust up against the top of the bag when filled. Such pocket has its open end directed inwardly of the bag and thus when the bag is illled and bounced oif from the filling machine spout, the material in the bag will thrust the greater part of the sleeve firmly up against the inside of the top of the bag, for effectively collapsing and closing the sleeve, and a mass of such material will be thrust into such pocket, such mass preventing the valve lip from being pushed up along with the collapsed sleeve and serving in effect as a wedge between the valve lip and the collapsed sleeve portions thereabove and acting thereafter to hold the outer portions of the sleeve collapsed in secure valve-closing condition.

If at least portions of the valve lip of such a construction are made relatively stiff as by pasting a plurality of plies thereof together without pasting same with respect to the collapsible sleeve portions thereabove,

p 2,891,716 `Paten-ital- ,Jurrie "23 1959 Vice then the closing effect due to such pocket will be espe# cially effective. l i i Preferably the sleeve in accordance with the inve'n tion is made at1its outer end'pwith a folded-,over'portion f orrningan inwardly directed cuff and l,theouter,surface of this culi is pasted to thetinside wall surfaces in the valve opening sothat the pocketvforms betweensuch cuff and the adjacent portions of the sleeve per-se; The material ofsuch cuff at this inner end may, if desired, be'continued'and folded outwardly to the outer end of the sleeve and thence again inwardly inside the sleeve for'somefdstance whereby theouter portions'fof the pocket will have at least' two plies.

`Other and more specific objects, features and fadvn'- tages Aof the inventionwillappear from the detailed description given below, taken in connection Awithftlna accompanying drawings which forrn- `a part .of `this specification and illustrate by way of examplethe present preferred embodiment of the invention. Iny the drawings: v t v v. Fig. 1 is a perspectveview of thevalve' corner of a Vbag made in accordance with the invention;Y r Figs, 2 and 3 respectively are fsectionalwiews ,taken substantially alonglines 2 2 audit-3y ofFig.1; yand Fig.` 4 is' a perspective view ,of a preferred forni', of sleeveadapted for use in accordance'gwith theinvention. Referring now to Fig. ,1i in further detail, a .multiwallxbag is here shownat 10 lhavingan; intlllrned'vaglve corner flap 11,`with overlying side ilapsf'of conventional `'formas atl12 and 13. The valve 'sleeve is indicatedat 14 and shown inv further, ydetail@beforedts insertion in .Fig- 4. p A s' shownin Fig'. y4,'.the Nsleeve may comprise adlttened Vtubular `feleniert fc'ir'rnefdat its outer-fend with Qa folded:- Qvf;p' fris, whenitinsefd 'meeba-isfdass@ inwardly f' the vane. The-upper sufefof' the can and under surface areas as at 16 insofar as same contact with the corner or side flaps in the valve, are adapted to be pasted to the latter. The areas on the inside of the cuif are free from pasting to the sleeve per se, so that a pocket opening inwardly of the bag is formed as indicated in Figs. 3 and 4. The sleeve may be formed by taking a suitable area of sheet material and folding it over to form the flattened tube as shown and with the folded-over edges overlapped and glued together as at 17 (Fig. 2). The surface of the sleeve which is to be the undersurface of the inner end thereof in the bag, may, if desired, be slit as indicated at 17a, such slit as shown being at a slightly angular position permitting the edges of the slit to overlap somewhat without wrinkling in case pressure is applied to the upper face areas of the filled bag tending to compress the sleeve edgewise. Various other forms of slits well known for such valve sleeves may be used, if desired. While ordinary at kraft paper may be used as the sleeve material, in some cases it may be preferred to use a relatively llexible laminate of two thin sheets of paper for example with a thin interposed asphalt layer therebetween or a sheet of paper coated with a film of polyethylene or other moisture-proof material may be used as is well understood in the art of manufacturing bag valve sleeves.

The sleeve may be inserted in the bag valve during the operation of bottoming the bag by the same type of automatic operations heretofore customary for inserting sleeves in pasted end bags. That is to say, the cui 15 in this case may have adhesive applied thereto or the bag ap surfaces which are to contact with the cuif may have suicient adhesive applied thereto so that when the sleeve is put into place, it will remain lodged with its outer end affixed and sealed with respect to the inside wall portions of the Valve. Bags in accordance with the invention may be lled on automatic filling machines in .the same manner as heretofore accomplished simply by placing the bagon 'the'fillrig spout of the machine with the spout extending into the' sleeve. And when the bag is lled and is dropped oi or bounced from the region of the lling spout Onto a 'conveyor for example, ,the material in thebag will be thrust up'agains't "theinterior of the top of the bag causing the inner portions of 'the sleeve to become collapsed as indicated' 'at'20 in Eig. '3. This will cause the upper e'nd of the bag to arch 'upwardly Somewhat including the portions as at 21 which "are located above the valve 'lip shown at 22 in Figi 3. Consequently a pocket as indicated will be formed into which a 'mass of the material will immediately lind its way,`thereafter acting in effect like a wedge preventing the valve lip' 22 from llexing' upwardly and keeping the sleeve portions as at 2.1 firmly collapsed even to the outermost portions as at A23 which will be exposed outside the valve. 'It would normally be expected that when the material inthe bag `forces the inner portions of the sleeve up Yto collapsed condition, the valve lip 22 would similarly be forced up against the top of thev bag, thus preventing the opening of any pocket for the reception of material as above described, `In fact heretofore so far as is known, it has been the universal practice so to secure the valve sleeves in such valves as to insure that the valve lip areas would be pulled or forced up against the top of the bag, it having been supposed that such a result was essential to good closing action of the valve. However, extensive tests have shown quite surprisingly that if the sleeve is so ksecured as above explained as to permit the pocket to be formed, then invariably the pulverulent or granular' material' in the bag will enter and more or less lill 'such pocket and therefore ajo'rd the above-explained wed'g'in'g 'effect forV firmly collapsing' and closing even the outermost 'portions' of' the sleeve.

Although a preferred embodiment of the invention is herein" disclosed'vfor purposes of'explanation, V'various modifications' thereof, after study of this "specification, inayY be apparent to those skilled in the art to which the georgia i invention pertains. Reference should accordingly be had to the appended claim in determining the scope of the vti., .i

What is claimed and desired to be secured by Letters Patent is:

ln a valve bag of the type having an end closure formed of corner aps and adhered overlying side aps and with one of the inturned 'underlying corner aps forming a valve lip, said side aps joining with corner flaps along diagonal foldlines, a sleeve positioned in the 'valve and normally atwise against the 'inside of the top of the bag when empty, 'such sleeve vhaving flexible portions protruding inwardly of the bag substantially beyond such lip and adapted to be pressed up against the inside of the top of the bag by material therein when filled, the outer end portion of the sleeve vbeing formed with a cuff directed inwardly of the bag, a part of the culled portion of the sleeve extending outwardly of the bag corner in exposed position beyond said diagonal fold lines, exterior portions of said cut being secured and sealed with respect to the interior walls of the valve, a pocket thereby being providedV when the bag is lilled, between the cul and 'other portions of the sleeve which are adapted to arch upwardly together with the top vof the bag, such pocket being open to the interior of the bag for receiving a mass of the material filled therein, whereby such mass will retain the sleeve portions thereabove up in collapsed valve-closing condition and with the valve lip portions spaced therebelow.

References Cited in the le of this patent STAEES PATENTS 2,040,335 -Rosmait May l2, 1936 2,275,505 Crawford Mar. 10, 1942 2,590,568 Peters Mar. 25, 1952 PORElGN PATENTS

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