Sandwich wrapper and method of wrapping

Hide panel

Patent issued

05/14/1996

Inventor(s):	Capy, Gilbert Benarrouch, Jacques Allain, Jean-Luc
Assignee	Wrapco International B.V. (Rotterdam)
Application	No. 08/136,188 filed on 12/06/1993
Current US Class	426/111, 426/106, 426/115, 426/410, 229/938, 53/465, 383/20
Field of search	229/87.03, 229/87.08, 229/DIG.4, 229/DIG.7, 229/DIG.13, 426/410, 426/106, 426/111, 426/115, 383/120, 206/410, 206/303, 53/465, 53/461, 53/466, 53/40, 493/394
International Classes:	B65D 6512
Examiners
Primary	Weinstein Steven
Attorney, agent or firm:	Kane, Dalsimer, Sullivan, Kurucz, Levy, Eisele and Richard
US patent references	397475, 834474, 1165644, 1628429, 1846584, 1846585, 1846949, 1920841, 1948615, 1951019, 2105368, 2109504, 2224504, 2586078, 2665001, 2705104, 2845215, 3120337, 3815649, 3955001, 4096987, 4137333, 4494785, 4795648
Foreign patents	86 03956 (03/17/1986, FR), 189654 (11/30/1922, GB)

A sandwich wrapper is formed from a substantially rectangular sheet byproviding a plurality of overlapping folds which are positioned into asubstantially pleated arrangement. Two substantially parallel lines ofadhesive, glue, or adhesive tape are used to attach spaced apart zones ofthe folded areas to each other. The dimensions of the sheet with respectto an article to be wrapped, spacing between the adhesive lines, anddimensions of the fold can be calculated to provide an efficient andcost-effective food wrapper.
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention generally relates to the packaging of convex shapedarticles, and more particularly to packaging for a variety of sandwiches,and specifically hamburger-type sandwiches.
2. Description of Background and Relevant Information
Presently, in France, a large number of fast food establishments have beendeveloped. The development of these types of establishments has resultedin the replacement of conventional French and similar restaurants; thesenew restaurants direct their efforts to developing meals which include around bun, cut at its center, parallel to its base, and filled with groundmeat, which sandwiches are commonly known as hamburgers.
Conventional hamburger sandwiches comprise a plurality of successivelypiled layers of round ground beef patties, bread slices, sauce, tomatoslices, and lettuce or other green vegetable slices, all of which areframed, both above and below, by two halves of a hamburger bun.
The hamburger sandwiches are prepared and are thereafter packaged, eitherin thin, resistant paper, or in an expanded polystyrene box. The paperwrapping is adapted to be used for small hamburger sandwiches, and issimilar to the wrapping used on round pieces of cheese; it is generallymore practical to remove the hamburger sandwich from its wrapping so thata consumer is able to eat it.
The expanded polystyrene box type of container is adapted to contain largerhamburger sandwiches, and it is imperative that the hamburger be removedfrom such box so that it can be eaten. One major disadvantage of ahamburger sandwich is that the meat, the vegetables, and the sauce whichcomprise the sandwich together form a mass which is substantial relativeto the mass of the bread. As a result, the act of biting into the sandwichcauses the garnish layers to slide with respect to each other, such thatthe hand of the user which holds the sandwich inevitably contacts thesauces and/or juices from the meat, all of which creates a tendency forthese materials to drip and stain the ties and clothing if a consumer isnot careful, particularly since they do not remain in the container wheneaten.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to providepackages for hamburgers and similar sandwiches which are adapted toovercome the above-identified problems and to minimize the discomfort of auser which result from contact of undesirable juices and food with theclothing of a user.
In a first aspect of the present invention, a wrapper is adapted to bepositioned about a solid article having a convex shape. The article has acentral axis passing through the geometric center of the solid, whereinthere are two intersecting planes which extend through the article, whichinclude the axis. The wrapper comprises a thin, flexible substantiallyrectangular sheet having a predetermined width and a predetermined length,determined by particular equations, with respect to the dimensions of theobject to be wrapped, set forth hereinafter, the sheet being folded into aplurality of folds which are substantially parallel to the width(substantially parallel to the length), wherein adjacent folds arepositioned on top of each other and are adhesively attached to each otheralong two narrow strip areas located adjacent two side edges of thesheets.
The folds can be glued to each other, soldered to each other by a heatsensitive adhesive, or elsewhere attached to each other by adhesive tapeattached to the sheet along the two strip areas.
The folds are positioned over each other in a lengthwise, staggered mannerin a pleated fashion, with the folds comprising first and second sets ofalternating width fold sections located along the sheet, wherein each ofthe fold sections in the first set of fold sections has a larger widththan each of the fold sections in the second set of fold sections.
The dimension and number of folds as well as the length of the folded,i.e., plated wrapper, are also determined by particular equations setforth hereinafter, and are also dependent upon the dimensions of thearticle to be wrapped.
Narrow strips comprise substantially parallel selvage area, with thedistance between selvage areas being equal to a value dependent upon thelength of the wrapper and dimensions of the article to be wrapped, as setforth hereinafter.
The sheet can include, e.g., an additional strip between each of theselvage areas and a side edge of the sheet, with each additional striphaving a width defined by the equation dependent upon the wrapper and thearticle to be wrapped, as set forth hereinafter. The additional strip caninclude a plurality of triangular recesses and triangular sections,wherein the width is measured to the peak of each of the sections, and thesheet can include a plurality of rounded corners.
Each of the folded areas are substantially equal, each folded area having asection of larger width and a section of a smaller width, the wrapperbeing adapted to cover a solid article in the form of a solid cylinder ofrevolution having a predetermined diameter and height, wherein the sheetwidth and length can be determined by particular equations with respect tothe dimensions of the article to be wrapped, as will be set forthhereinafter.
Each of the strips has a width which is less than 5% of the sheet width,and the folds can be attached to each other by thermally-activated glueattached to the sheet prior to formation of the folds. Alternately, thefolds can be attached to each other by heat and pressure when the foldsare formed.
The sheet has a front surface and a rear surface, wherein the attachmentstrips can be located along both of the surfaces. The wrapper can beformed from a material which, when subjected to heat and pressure, willattach the folds to each other along both of the strips.
If desired, the folds can be attached to each other only along the strips.
The wrapper may comprise a thin paper sheet, wherein the folded areas areattached to each other by a plastic film along the strips, or the sheetcan comprise a thin, flexible plastic film; the film can be a single filmsheet, or a plurality of laminated sheets.
A plurality of the sheets can be provided in the form of a continuous rollof the material, the roll having a predetermined width, wherein theattachment strips are separated from each other by alternating distances,respectively. Each sheet includes a plurality of folds and a non-foldedportion, the non-folded portion comprising means for facilitatingseparation of adjacent sheets from the roll.
In a second aspect, the present invention provides a method of wrapping asandwich with a substantially rectangular wrapper having a predeterminedlength, a predetermined width, and a plurality of folded portions arrangedsubstantially parallel to the width and overlapping each other in apleated fashion, with the portions being adhered to each other alongsubstantially folded parallel, spaced adhesive strips perpendicularlyarranged with respect to the folded areas. The method comprises placing afirst end of the wrapper into abutment with a peripheral portion of thesandwich, with the folded areas being substantially vertical, pulling anopposed second end of the wrapper about the sandwich, wherein the areas ofthe wrapper between the strips and side edges of the wrapper will formgenerally circular areas on the top and bottom of the sandwich as thepleats are unfolded, and attaching the first and second wrapper ends toeach other.
In a third aspect of the present invention, a sandwich wrapper is formedfrom a thin, substantially rectangular sheet having opposed first andsecond ends and opposed first and second sides, the sheet comprising aplurality of overlapping folds arranged in a pleated fashion, the foldsextending generally parallel to the edges and being separably attached toeach other by substantially narrow adhesive areas arranged parallel toeach other and to the sides, and perpendicularly with respect to thefolds.
Each of the strips is spaced away from a respective one of the sides by anedge area of a predetermined distance.
Each of the folds comprises a first, relatively wide section of a firstwidth and a, relatively narrow section of a second width, and all of thecorners of the sheet can be rounded. Each of the edge areas can beprovided to have a constant width.
A plurality of spaced triangular portions can be positioned adjacent thesheet sides, which portions will be adapted to overlap each other when thewrapper is wrapped about a food article.
The adhesive areas can extend along only a portion of the sheet sides. Thewrapper is to be wrapped about a substantially cylindrical hamburgersandwich having a predetermined height and diameter, and the sheet has apredetermined width and a predetermined length, taking into account asandwich-covering coefficient which will be set forth hereinafter. Each ofthe folds includes a relatively wide section and a relatively narrowsection, defined by a predetermined relationship, and the length of thesheet, when folded, is also defined by a predetermined relationship, suchrelationships set forth hereinafter. The distance between the adhesiveareas is likewise defined by a particular relationship also set forthhereinafter.

What is claimed is: .[.1. A wrapper adapted to be positioned about and wrapa solid article having a convex shape, said article having a central axispassing through the geometric center of said solid, wherein twointersecting planes extend through said article and include said axis,wherein said wrapper comprises a thin, flexible substantially rectangularsheet having a predetermined width and a predetermined length, said sheetcomprising two lengthwise-extending opposing side edges and first andsecond opposing ends, said sheet further being folded into a plurality offolds which extend substantially parallel to said width, wherein adjacentfolds are positioned on top of and overlap each other in a lengthwise,staggered manner and are adhesively attached to each other along twolengthwise-extending narrow strip areas located, respectively, proximatesaid two side edges of said sheet, said wrapper, including said stripareas, being dimensioned and configured relative to said article such thatupon holding one of said ends of said wrapper against said article andpulling the opposite one of said ends of said wrapper about the peripheryof said article, said plurality of folds between said strip areas at leastpartially unfold to allow said wrapper to encompass the periphery of saidarticle, whereas portions of said wrapper adjacent said strip areas andsaid side edges tend to move together, respectively, to cause saidportions to fold over and under said article to substantially enclose said
article..].2. A wrapper in accordance with claim .[.1.].
.Iadd.37.Iaddend., wherein said folds are glued to each other. 3. Awrapper in accordance with claim .[.1.]. .Iadd.37.Iaddend., wherein said
folds are soldered to each other by a heat sensitive adhesive. 4. Awrapper in accordance with claim .[.1.]. .Iadd.37.Iaddend., wherein saidfolds are attached to each other by adhesive tape attached to the sheetalong said two strip areas. .[.5. A wrapper in accordance with claim 1wherein said folds are positioned over each other in a pleated fashion,said folds comprising first and second sets of alternating width sectionslocated along said sheet, wherein each of the fold sections in the firstset of fold sections has a larger width than each of the fold sections inthe second set of fold sections, thus producing a staggered array..]..[.6.A wrapper in accordance with claim 5, wherein said narrow strip areascomprise substantially parallel selvage areas, with the distance (M)between said selvage areas being equal to M=P/2-L/3.14(1+alpha).+-.5%,wherein P is defined as the length of the closed curve formed by theintersection of a first one of said planes and one arcuate surface of saidarticle, and wherein M is the distance between the strip areas and whereinsaid sheet length (L) is defined by the equation L=R(1+alpha), wherein0.2.].7. A wrapper in accordance with claim .[.6.]. .Iadd.37.Iaddend.,wherein said sheet width (K) is defined by the equation K=P/2.+-.5% and,further.Iadd., wherein said narrow strip areas comprise selvage areas,.Iaddend.wherein said sheet includes an additional strip between each ofsaid selvage areas and a side edge of said sheet, each additional strip
having a width (C) defined by the equation C=P/4-M/2. 8. A wrapper inaccordance with claim 7, wherein said additional strip includes aplurality of triangular recesses and triangular sections, wherein said
width (C) is measured to the peak of each of said sections. 9. A wrapperin accordance with claim 8, wherein said sheet includes a plurality of
rounded corners. 10. A wrapper in accordance with claim .[.1.]..Iadd.37.Iaddend., wherein each of the .[.folded areas.]. .Iadd.folds.Iaddend.are substantially equal, .[.each folded area comprising a largersection of width A and a smaller section of width B,.]. said wrapper beingadapted to cover an article in the form of a solid cylinder of revolutionhaving a diameter D and a height H, wherein the sheet width K=D+H.+-.5%,the sheet length L=3.14D(1+alpha), .[.wherein 0.2.[.strips.]. .Iadd.narrow strip areas.Iaddend.. 11. A wrapper inaccordance with claim .[.1.]. .Iadd.37 .Iaddend.wherein each of said.[.strips.]. .Iadd.strip areas .Iaddend.has a width which is less than 5%
of the sheet width .[.K.]. (.Iadd.K).Iaddend.. 12. A wrapper in accordancewith claim .[.1.]. .Iadd.37 .Iaddend.wherein said folds are attached toeach other by thermally-activated glue attached to said sheet prior to
formation of said folds. 13. A wrapper in accordance with claim 12 whereinsaid folds are attached to each other by heat and pressure when the folds
are formed. 14. A wrapper in accordance with claim .[.1.]..Iadd.37.Iaddend., wherein said sheet has a front surface and a rearsurface, and wherein said .[.strips.]. .Iadd.strip areas .Iaddend.are
located along both of said surfaces. 15. A wrapper in accordance withclaim .[.1.]. .Iadd.37.Iaddend., wherein said wrapper is formed from amaterial which, when subjected to heat and pressure, will attach the foldsto each other along both of said .[.strips.]. .Iadd.strip areas.Iaddend..
6. A wrapper in accordance with claim 15, wherein said folds are attachedto each other only along said .[.strips.]. .Iadd.strip areas.Iaddend..
A wrapper in accordance with claim .[.1.]. .Iadd.37 .Iaddend.whichcomprises a thin paper sheet, wherein said .[.folded areas.]. .Iadd.folds.Iaddend.are attached to each other by a plastic film along said
.[.strips.]. .Iadd.strip areas.Iaddend.. 18. A wrapper in accordance withclaim .[.1.]. .Iadd.37 .Iaddend.wherein said sheet comprises a thin,
flexible plastic film. 19. A wrapper in accordance with claim 18
comprising a single film sheet. 20. A wrapper in accordance with claim 18
comprising a plurality of laminated sheets. 21. A wrapper in accordancewith claim .[.1.]. .Iadd.37 .Iaddend.comprising a plurality of sheets on a
continuous roll of said material. 22. A wrapper in accordance with claim21, wherein each sheet includes a plurality of folds and a non-foldedportion, said non-folded portion comprising means for facilitatingseparation of adjacent sheets from said roll. .[.23. A method of wrappingan article having a predetermined shape with a substantially rectangularwrapper having a predetermined shape with a substantially rectangularwrapper having a predetermined length, a predetermined width, opposing endportions and opposing side edges, and a plurality of folded portionsarranged substantially parallel to said width and overlapping each otherin a lengthwise staggered, pleated fashion, said folded portions beingadhered to each other along substantially parallel, spaced longitudinaladhesive strip areas substantially perpendicularly arranged with respectto said folded areas, said method comprising:
(a) placing one of said end portions of said wrapper into abutment with aperipheral portion of said article, with said wrapper being substantiallyflat;
(b) pulling the opposite one of said ends of said wrapper about theperiphery of said article such that said plurality of folds between saidstrip areas at least partially unfold to allow said wrapper to encompassthe periphery of said article, whereas portions of said wrapper adjacentsaid strip areas and said side edges tend to move together, respectively,to cause said portions to fold over and under said article to
substantially enclose said article..]. 24. The method of wrapping anarticle in accordance with claim .[.23.]. .Iadd.38.Iaddend., wherein saidarticle is a food product and said method is a method of wrapping said
food product. 25. The method of wrapping an article in accordance withclaim .[.24.]. .Iadd.38.Iaddend., wherein said food product is a sandwichand said method is a method of wrapping said sandwich. .[.26. A sandwichwrapper formed from a thin, substantially rectangular sheet having opposedfirst and second ends defining a length between them and opposed first andsecond sides, said sheet comprising a plurality of lengthwise staggered,overlapping folds arranged in pleated fashion, said folds extendinggenerally parallel to said ends and being attached to each other bysubstantially narrow adhesive strip areas arranged substantially parallelto each other and to said first and second sides and substantiallyperpendicularly with respect to said folds, said wrapper, including saidstrip areas, being dimensioned and configured relative to said sandwichsuch that upon holding one of said ends of said wrapper against saidsandwich and pulling the opposite one of said ends of said wrapper aboutthe periphery of said sandwich, said plurality of folds between said stripareas at least partially unfold to allow said wrapper to encompass theperiphery of said sandwich, whereas portions of said wrapper adjacent saidstrip areas and said side edge tend to move together, respectively, tocause said portions to fold over and under said sandwich to substantiallyenclose said sandwich..]..[.27. A wrapper in accordance with claim 26,wherein each of said strip areas is spaced from a respective one of saidsides by an edge area of a predetermined distance..]..[.28. A wrapper inaccordance with claim 27 wherein each of said folds comprises a first,relatively wide section of width A and a second, relatively narrow sectionof width B..]..[.29. A wrapper in accordance with claim 27 wherein all ofthe corners of said sheet are rounded..]..[.30. A wrapper in accordancewith claim 27 wherein each of said edge areas has a constant
width..]..[. . A wrapper in accordance with claim 30, wherein said stripareas extend along only a portion of said sheet sides..]..[.32. A wrapperin accordance with claim 27, wherein said wrapper is wrapped about asubstantially cylindrical hamburger sandwich having a height H and adiameter D..]..[.33. A wrapper in accordance with claim 32 wherein saidsheet has a width K=D+H.+-.5% and a length L=3.14(1+alpha), where alpha isan optimum sandwich covering coefficient between 0.2 and 0.6..]..[.34. Awrapper in accordance with claim 32 wherein each of said folds comprises awide section of width A and a relatively narrow section of width B,wherein D4>A>D/10,5/6A>B>A/3, and the length of the sheet, when folded, isdefined by L'=N(A-B), where N is the number of folds in thesheet..]..[.35. A wrapper in accordance with claim 32 wherein the distancebetween the adhesive areas is defined byM=2B.times.D/A+B+H.+-.5%..]..[.36. A wrapper in accordance with claim 26further comprising a plurality of spaced triangular portions adjacent saidsheet sides which are adapted to overlap each other when said wrapper is
wrapped about a food article..]..Iadd.37. A wrapper adapted to bepositioned about and wrap a solid article having a convex shape, saidarticle having a central axis passing through the geometric center of saidsolid, wherein two intersecting planes extend through said article andinclude said axis, wherein said wrapper comprises a thin, flexiblesubstantially rectangular sheet having a predetermined sheet width (K) anda predetermined sheet length (L), said sheet comprising twolengthwise-extending opposing side edges and first and second opposingends, said sheet further being folded into a plurality of folds whichextend substantially parallel to said width, wherein adjacent folds arepositioned on top of and overlap each other in a lengthwise, staggeredmanner and are adhesively attached to each other along twolengthwise-extending narrow strip areas separated by a distance M located,respectively, proximate said two side edges of said sheet to form apleated wrapper, said wrapper, including said strip areas, beingdimensioned and configured relative to said article such that upon holdingone of said ends of said wrapper against said article and pulling theopposite one of said ends of said wrapper about the periphery of saidarticle, said plurality of folds between said strip areas at leastpartially unfold to allow said wrapper to encompass the periphery of saidarticle, whereas portions of said wrapper adjacent said strip areas andsaid side edges tend to move together, respectively, to cause saidportions to fold over and under said article to substantially enclose saidarticle wherein each fold comprises a larger section of width A and asmaller section of width B connected to and folded relative to the largersection;
wherein A, B and M are defined by
(R/31.4(A/3M=(P/2)-L'/3.14* (1+alpha)+/-5%;
wherein P is a length of a closed curve formed by the intersection of afirst of said planes and a first arcuate surface of said article; R is alength of a closed curve formed by the intersection of a second of saidplanes and a second arcuate surface of said article, said second planebeing substantially perpendicular to said first plane; L' is the length ofthe pleated wrapper; and alpha has a value between 0.2 and 0.6..Iaddend..Iadd.38. A method of wrapping an article having a predeterminedshape with a substantially rectangular wrapper said article having ageometric center and central axis passing through said geometric centerwith two intersecting planes extending through said article and includingsaid central axis, said wrapper having a predetermined length, apredetermined width, opposing end portions and opposing side edges, and aplurality of folded portions arranged substantially parallel to said widthand overlapping each other in a lengthwise staggered, pleated fashion,said folded portions being adhered to each other along substantiallyparallel spaced longitudinal adhesive strip areas substantiallyperpendicularly arranged with respect to said folded areas and separatedby a distance M, wherein each fold comprises a larger section of width Aand a smaller section of width B connected to and folded relative to thelarger section;
wherein A, B and M are defined by
(R/31.4)(A/3)M=(P/2)-L'/3.14* (1+alpha)+/-5%;
wherein P is a length of a closed curve formed by the intersection of afirst of said planes and a first arcuate surface of said article; R is alength of a closed curve formed by the intersection of a second of saidplanes and a second arcuate surface of said article, said second planebeing substantially perpendicular to said first plane; L' is the length ofthe pleated wrapper; and alpha has a value between 0.2 and 0.6
(a) placing one said end portions of said wrapper into abutment with aperipheral portion of said article, with said wrapper being substantiallyflat;
(b) pulling the opposite one of said ends of said wrapper about theperiphery of said article such that said plurality of folds between saidstrip areas at least partially unfold to allow said wrapper to encompassthe periphery of said article, whereas portions of said wrapper adjacentsaid strip areas and said side edges tend to move together, respectively,to cause said portions to fold over and under said article tosubstantially enclose said article..Iaddend.

BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features, and advantages of the presentinvention will now be described more specifically with reference to theattached drawings, which are provided by way of non-limiting example only,wherein like reference numerals are used to identify similar partsthroughout the several views, and wherein:
FIG. 1 is a plan view of a sheet formed in accordance with the presentinvention which comprises a wrapping prior to folding, includingcross-hatching in zones 16 and 17, where adhesive is placed for attachinga plurality of folded areas to each other;
FIG. 2 is a plan view of the sheet of FIG. 1 after it has been folded andafter which folded areas are attached to each other by bands 13 and 14;
FIG. 3 is a perspective view of a first phase or stage of wrapping ahamburger sandwich with the folded wrapper of FIG. 2;
FIG. 4 is a perspective view of a subsequent stage of folding the wrapperof FIG. 2 about a hamburger sandwich;
FIG. 5 is a perspective view of a final stage in which the wrapper of FIGS.2-4 has been wrapped about a hamburger sandwich;
FIG. 6 is a detailed plan view of the sheet prior to being folded,illustrating, in dashed lines, the future locations of folds indicated bya set 42 of reference letters a-f;
FIG. 7 is a sectional view illustrating the wrapper after it has beenfolded, illustrating the manner in which the folds of the folded sheet arepositioned with respect to each other;
FIG. 8 is a top plan view of the wrapper of FIG. 6 after a plurality offolds have been formed;
FIG. 9 is a cutaway plan view of a second embodiment of a wrapper formed inaccordance with the present invention, in which a plurality of recessed orcutaway zones 31, each having a predetermined width C, are provided, whichwrapper is adapted to reduce the amount of wrinkles on the wrapping paperwithin a circle 27 when the wrapper is positioned about a food article tobe protected;
FIG. 10 is a partial or cutaway plan view of a wrapper having a cutout orrecessed area adjacent to a strip of adhesive film; and
FIG. 11 is a perspective view of a substantially convex object which isadapted to be covered by a wrapper in accordance with another embodimentof the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
It is an object of the present invention to provide a sandwich wrappingwhich is adapted, on one hand, to be positioned about a hamburger sandwichin a relatively simple manner, and on the other hand, which is capable ofprotecting a hamburger sandwich during transport of the sandwich, and toprotect, during consumption of the sandwich, a consumer against drips andstains which otherwise would result, i.e., it will serve as a receptacleduring consumption. Thereafter, when a consumer has finished eating hishamburger, it is only necessary to crumple the wrapping paper into a balland to throw it into the first garbage receptacle which is available.
Additionally, the wrapping can be mass-produced in large quantities in acontinuous fashion; it is further advantageous that the present wrapperuses a smaller quantity of material than that used in conventionalwrappers, and puts this lesser amount of material to better use. Finally,a wrapper in accordance with the present invention can be stored in a flatfashion so that it efficiently fills cartons and comprises an efficientload for pallets.
The combination of all of these advantages results in a product which hasan extremely attractive performance-to-price ratio.
The present wrapping is adapted to wrap a hamburger sandwich, whichsandwich is best illustrated in FIG. 3. The sandwich is substantiallycylindrical and has a diameter D (or 4) and a height H (or 5), as bestseen in FIG. 3.
The main parameters and characteristics of the wrapping will now bedescribed. The wrapping preferably comprises a sheet of paper 6, as sheenin FIG. 1, which is thin and flexible, and which has a weight ofapproximately 20-30 g/M.sub.2. The paper has good tear-resistance via itsincorporation of relatively long fibers, and can possibly even be coatedwith polyethylene to increase this desirable resistance. It is also clearthat the use of a relatively simple or complex plastic film iscontemplated as being within the scope of the invention, rather thanpaper.
As seen in FIG. 1, the sheet is substantially rectangular and has a width 7(or K), which width is selected in accordance with the equationK=D+H.+-.5%. The length of the sheet is represented by L, where L isdetermined in accordance with the equation L=3.14D(1+alpha), where alphais the optimum covering coefficient, which is between 0.2 and 0.6. Inother words, the length of the wrapper L is calculated in accordance withthe circumference of the hamburger (.pi.D) multiplied by the number oftimes that the wrapper is to surround the hamburger (either partially orcompletely).
The sheet is then provided with a plurality of accordion folds 9, as bestseen in FIG. 7. The accordion folds are dissymetric and are positionedparallel to the width 7 of the sheet. Between the successive folded orpleated areas, as shown in FIGS. 6 and 7, alternating distances areprovided; as shown in FIG. 7, a first set of distances 11, between foldlines in a relatively short series of folds on the paper is provided witheach equal to the distance B in FIG. 6; and there is also a second set ofdistances 10 between some of the adjacent fold lines, which distances areeach equivalent to A, which is the distance between the farther spacedapart fold lines on the wrapper in FIG. 6. As seen in the drawings, thedistance B is less than the distance A. The value of the distance A isselected as a function of the hamburger sandwich to be wrapped, such thatA is selected to be between D/4 and D/10. By so selecting the largerdistance A, the wrapper will not have folding dimensions which are eithertoo large or too small, which too large or too small dimensions wouldotherwise interfere with proper operation of the wrapper when it is used.The distances B, between the more closely spaced fold lines, is between5/6 and 1/3 of the distance A.
Once folding has been performed, a rectangular folded wrapper is formed, asseen in FIG. 2, which still has the original width 7 with a value K as inthe starting, unfolded sheet or wrapper of FIG. 1, and which also has alength with a value which has been substantially reduced. In essence, eachcompleted fold comprises a portion of the folded wrapper which includes astrip of width A and a strip of width B. In this manner, the number offolds N which can be formed in the sheet is determined by the followingequation: N=the largest whole number determined by the calculationL/(A+B), if all of the folds are formed of equal length. Obviously, therewill be an additional amount of material which will remain and which willnot form one of the folds N if the total length L of the unfolded wrapperis greater by some amount than a numerical factor multiplied by (A+B).
The new length 12 of the folded wrapper is represented by the value L',which is determined by the following equation: L'=N(A-B)+B. As clearlyseen in FIGS. 6, 7, and 8, the amount (A-B) corresponds to the path orextent 28 of each fold. In practice, the distance L' will be slightlylarger than as calculated by the above formula because, in order tofacilitate cutting between two wrappers, a small zone having no folds isleft between each set of N folds. The folded areas are then attached toeach other along two narrow, substantially parallel strips 13 and 14, asseen in FIG. 2, which strips are positioned symmetrically along both sidesof the axis of symmetry 15 of the wrapper which is located perpendicularto the folds, again as seen in FIG. 2.
Gluing of the folds can be achieved in various fashions.
It is possible to coat the wrapping paper prior to folding with strips 16and 17 (see FIG. 1) of a product which will adhere to the wrapper surfaceunder contact and pressure, under either hot or cold temperatures. Forexample, a cold adhesive can be used which will attach/adhere the folds toeach other as soon as the folds are folded back on each other and pressureis applied to them.
After folding, it is possible to glue the folds, via hot pressing, by usinga thermally activatable strip which has been previously positioned on thewrapping paper. From experience, it is preferable to deposit a strip ofsuch glue on each side of the unfolded wrapper or sheet 6 so that thefolds will be glued to each other along both sides of the fold.
It is also possible to deposit a strip of adhesive film, after folding, tohold the folds together. As in the above embodiments, better grip andadhesion between the folds will be obtained if the adhesive is placed onboth sides of the wrapper.
For proper operation of the wrapper, the width of each attachment band 13or 14 which attaches the folds to each other must be less than 5% of thewidth K of the wrapper. In this fashion, a zone 18 having a width M isformed between the inner boundaries or selvage areas of each of theattachment strips 13 and 14, as best shown in FIG. 1. This zone is locatedbetween the attachment strips and is free to be unfolded when the wrapperis eventually wrapped about a hamburger sandwich. The wrapper thusobtained is used in a fashion as described hereinafter, as firstillustrated with reference to FIG. 3.
In use, first end portion 20 of the wrapper is applied on or positioned inabutment with a cylindrical peripheral portion of the hamburger sandwichsuch that the folds will be located parallel to axis 19 of the cylindricalsandwich. The median portion 15 of the wrapper, which is locatedperpendicular to each of the folds, is located substantially in the middleof the height H (or 5) of the cylindrical sandwich. The hamburger ispreferably held between the thumb and the middle finger of the left handof a consumer so that the index finger of the consumer will be free toretain end portion 20 of the wrapper against the hamburger. The free orsecond end portion 21 of the wrapper, adjacent median portion 15 of thewrapper, is then grabbed and the consumer pulls (as seen in FIG. 4) thewrapper in a fashion so as to undo the folds in a "rolling" fashion. Whenthe wrapper is so unfolded, edge portions 22 naturally tend to movetogether, folding over the upper and lower circular surfaces 23 and 24 ofthe sandwich. The upper strip 13, which serves to attach the foldstogether, thus defines a circle 27 (see FIG. 5), the position of whichdepends upon the distance between attachment strip 13 and attachment strip14.
For the wrapper to be unfolded properly, the distance 18, represented by M,which represents the width between the internal selvage portions 25 and 26of attachment strips 13 and 14 (see FIG. 2) is preferably of a particulardimension which is calculated as follows:
M=(2B.times.D)/(A+B)+H.+-.5%
It has been observed that if M is too small a value, it will be difficultto unfold the folds from the pleated wrapper, and if M is too large, thewrapper will form a conical area over the circular surfaces of thehamburger sandwich, which conical area is difficult to flatten out.
All that portion of the paper wrapped situated along both sides of theinterior selvage of the attachment strips is positioned so as to form acircle 27 defined by the selvage 25. If left unattended, folding of thissection will have wrinkles which can, however, be attenuated by providinga plurality of cutouts 29 (see FIG. 9) in a manner so as to eliminateexcess paper. These cutouts are formed in one embodiment, in a triangularconfiguration. Additionally, better coverage of the sandwich can beprovided by rounding the wrapper corners 32.
In an alternate embodiment of the invention, a wrapper is provided whichbegins with a sheet having a width K', or 30 as seen in FIG. 10. Width K'is defined here as being equal to the value M, increased by the width ofeach of the attachment strips along the folded areas. Thereafter, thesheet is folded as in the first embodiment, and a non-folded strip portion34 having a width 31 defined by C=1/2 (D+H-M), which is used to attach thefolds and which is located rightwardly of the attachment strip, comprisesa plurality of triangular cutouts. The triangular cutouts make itpossible, during positioning of the wrapper around a hamburger, to fill acircle 27 defined by the internal selvages 25 and 26 of the attachmentstrips, with the triangular portions 34 overlapping one another in ascale-like or roof-tile fashion.
It has further been found that, if B is selected to be less than or equalto A/2, the embodiment of FIG. 10 is an appropriate solution for wrappinga hamburger. However, if B is greater than A/2 but less than 2A/3, it ispreferable to form the triangular cutouts during the folding process.Finally, if B is greater than or equal to 2A/3 and less than or equal to5A/6, it is possible to use the wrapper without forming triangular cutoutsduring folding; in this case, adhesive ribbons are preferably not utilizedto attach the folds, because the contact surfaces between the adhesiveribbon and the triangular cutouts would provide an adhesive contact areawhich would become unduly weak.
The manufacture of the wrapper is effected from a roll of paper or thinplastic film having a substantial width. In one example, thermallyactivatable glue strips are continuously positioned along the roll of thinplastic film or paper in the direction of movement of the sheet from theroll; these strips will alternately be spaced from each other by distancesM and K-M, respectively. Folding is effect in a perpendicular fashion withrespect to the direction of movement of the sheet. The cutting of stripsof width K occurs just prior to folding, and gluing of the folds occursduring hot pressing which occurs after folding. Finally, the machineprovides a non-folded strip along every N folds, and it is in the zone ofthe non-folded portion of the wrapper that the wrapper is cut, therebydefining a folded wrapper having a length L'.
The above embodiments have been directed to a wrapper which is adapted toassume a cylindrical shape when it is wrapped about a cylindrical article.The same wrapper can, however, be perfectly adapted to any convexconfiguration 35, as shown in FIG. 11; specifically, it is adapted toconform to the shape of any convex article between a cylindrical and aspherical shape, including, e.g., ovoidal and ellipsoidal configurations.The characteristics of such a wrapper are defined with respect to thedirection at which first end 20 of the wrapper is positioned. An axis 37is defined, as shown in FIG. 11, which will be parallel to the folds ofthe wrapper and which will pass through the isobar center (when usedherein, isobar center refers to the geometric center of a solid article)36 of the shaped article. The surface of the convexly shaped article willintersect with a plane 39 which passes through axis 37; this intersectionwill form a closed curve 38 having a length P. A plane 40 passes throughthe isobar center 36 perpendicular to axis 37, cutting the surface of theconvexly shaped article 35 along a closed curve 41 having a length R.
With these parameters, the dimensions of the wrapper are preferablycalculated in accordance with the following formulae:
K=P/2.+-.5%; L=R(1+alpha), where 0.2Finally, it is possible in any of these wrappers to have fold interruptionsor folds of variable dimensions. Under these conditions, assuming that thefolds are identified by a series 1,2, . . . , i . . . , N, where each fold"i" is characterized by Ai and Bi, the formulas noted directly abovebecome:
R/31.4and
Ai/3where Ai and Bi will assume random values within their respective ranges ofvariation.
In this case, N is defined such that##EQU1##
Under these conditions an approach value of L' can be defined which issufficiently precise such that the determination of other parameters,i.e., M and C, can be calculated in accordance with the formulas describedabove, i.e., L' is defined by##EQU2##
The present application has proposed securing the folds by means of athermally activatable glue, which has previously been disposed orpositioned along the wrapping sheet. Instead, a component on the sheetitself could be used to attach the folds to each other by hot pressing thefolds between two thermal electrodes, or other equivalent systems could beused to form strips 13 or 14 of desired widths. This technique can be usedwhenever the structure comprises, along its exterior surface, a plasticfilm such as polyethylene, and under such conditions, the folds will beheat-soldered.
Although the present invention has been described with respect to specificmeans, materials, and embodiments, it is to be understood that theinvention is not limited to the particular embodiments disclosed, andextends to all equivalents which are within the scope of the claimshereinafter.