US3424366A - Hinged hollow walled carton and blank therefor - Google Patents

Description

Jan. 28, 1969 M. l. WILLIAMSON HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Filed NOV. 21, 1966 of IQ Sheet INVENTOR Marx/4a Z Uzi/441.50

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' Jan. 28, 1969 1. WILLIAMSON HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Filed Nov. 21. 1966 Sheet N?) NM Wmw m INVENTOR Niki/M44 I. lV tL A/widnl 1m 1969 M. l. WILLIAMS-ON 3,424,366

HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Filed Nov. 21, 1966 Sheet 3 of 10 F/a/z a 2 3 F/G l3 J 4 INVENTOR.

anew/4a f. wuuawofl Jan. 28, 1969 M. WILLIAMSON HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Sheet 4 of 10 Filed Nov. 21, 1966 INVENTOR.

M466 4: L :1. M 4 z MMJa/J 1969 M. l. WILLIAMSON 3,

HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Filed Nov. 21, 1966 Sheet 5 of l0 INVENTQR. I M42544 1'. WAftAqMJO/l/ F BY Jan. 28, 1969 M. WILLIAMSON- HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Filed Nov. 21, 1966 Sheet INVENTOR. MARJ'HIL l 1'. W/l l I4MJO/V BY v I m, awq ywt Jan. 28, 1969 M. WILLIAMSON HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Filed Nov. 21, 1966 Sheet INVENTOR.

14?.941: I. W/41/4MJ0A/ Jan. 28, 1969 M. 1. WILLIAMSON HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Filed Nov. 21, 1966 Sheet ,7 4% ATTORNEYS 1969 M. WILLIAMSON- 3,424,365

HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Filed Nov. 21, 1966 Sheet 9 of 10 INVENTOR.

Niki/I411 J1 WILL 4 4F041 n- 2 1969 M. I. WILLIAMSON 2 HINGED HOLLOW WALLIED. CARTON AND BLANK THEREFOR Filed NOV. 21, 1966 Sheet of 10 rn I ATTO United States Patent O 3,424,366 HINGED HOLLOW WALLED CARTON AND BLANK THEREFOR Marshall I. Williamson, P.O. Box 2975, New Haven, Conn. 06515 Filed Nov. 21, 1966, Ser. No. 595,991 US. Cl. 229-31 22 Claims Int. Cl. B65d /24, 5/22 ABSTRACT OF THE DISCLOSURE Hollow walled folding cartons, including cut and creased blanks for the same, wherein the cartons have hollow side walls of polygonal cross-section, the blanks being made in sections hingedly joined together and with the hollow side walls specially constructed at these joints to provide for the folding of the upstanding hollow side walls.

This invention relates to hollow-walled folding cartons and to cut and creased blanks of foldable material from which they are formed and initially erected into open tray-like shape or condition and then readily converted into various other useful forms hereinafter described.

The invention provides a unique hinge construction intermediate the ends of such an erected tray-like hollow walled carton, which is integral therewith and which enables it to be secondarily folded from its initial open, tray-like status to fully closable book-line form, or other attractive form for the packaging or display of various retail merchandise, where the section or part on one side of the-hinge is folded out of the plane of the other section. The hollow side walls of such a carton may be of any polygonal cross section but, as best suited to the present invention, are of triangular cross section.

The hinge construction of the invention is unique in that it not only permits but automatically assists and controls the transverse folding of the erected three dimensional triangular hollow side walls of the carton despite their otherwise strong resistance to such transverse foldmg.

The invention provides for making from a single out and creased blank the open-tray carton having hollow triangular walls, and also the closed carton having a receptacle portion, section or part, a back part, and a cover part, all three having hollow triangular side walls, the

back portion being foldable with respect to the receptacle part and the cover part with respect to the back part so that the cover portion will close on the receptacle portion with the apexes of its triangular side walls resting squarely on the apexes of the similar walls of the receptacle. Cartons of this type are advantageous both because of their economy their attractive appearance and because of the facility with which they they may be stacked, either empty or filled with merchandise. Also various forms of the carton are well adapted for use in shrink film packaging, inasmuch as the shrinking of the film will not cause shifting or deformation of the hollow triangular walls.

The carton blank may be made from any suitable foldable material, although advantageously it is made of paperboard, and also advantageously the direction of the grain of the paperboard is lengthwise of the blank or longitudinally of the side walls of the carton. The direction of grain is important in the mechanical folding of the side wall panels and in the subsequent functioning of the carton. A further advantage is that the transverse folding of the end panelsresults in flat exterior surfaces free of bulging which would be present if the grain were in the longitudinal direction of the end panels.

In accordance with the invention the stray-like carton is arranged to have a main panel with hollow triangular 3,424,366 Patented Jan. 28, 1969 sidewalls and one or more crosswise hinge lines dividing the panel and the side walls into two or more portions. The portions of the side walls on opposite sides of the hinge line have cooperating components which are foldable into telescoping relation and form mitered joints when the portions are folded relative to each other. The components of the one side of each of the hollow triangular wall portions on the opposite sides of the hinge ilne are interconnected by a web section.

The wall of each hollow triangular side wall opposite the web section is interrupted and provided with terminal components which slide into telescoping engagement with one another when the portions of the tray-like carton are folded about the hinge line. The parts forming the web section cooperate with the terminal components to facilitate their telescoping action.

As the result of this unique hinge construction not only are the three dimensional hollow triangular walls folded the one with respect to the other, but they are folded in such a way that an attractive exterior is provided. Moreover, if desired, the cover section and back section of the box can be raised to any desired angle for display purposes, and will remain in the positions to which they have been moved.

The flat blank for the tray-like carton can be made on standard machines and is easy to set up. The necessary folding and setting up operations to form this carton and also the several other related cartons to be later described can be performed mechanically or manually.

The invention will now be further described in connection with the accompanying drawings.

'- In these drawings:

. FIG. 1 is a projectional view of the carton of the invention in open tray-like form or condition;

FIG. 2 is a similar view showing the carton of FIG. 1 secondarily folded to form a closed carton;

FIG. 3 shows the carton of FIG. 1 partially folded towards the condition of FIG. 2;

FIGS. 4-7 are projectional views drawn to a much smaller scale showing cartons of various shapes folded from portions of the tray-like carton of FIG. 1 having their dimensions varied as required in order to form any of the particular shapes shown. Thus FIG. 4 shows a carton in the form of a closed triangle, FIG. 5 an L- shaped carton, FIG. 6, a C-shaped, and FIG 7 shows a carton having 5 folded sections instead of 3 as in FIGS. 1, 4 and 6;

FIG. 8 is a plan view of a flat sheet blank from which the tray-like carton of FIG. 1 is made just as it is cut out and creased by, for example, a steel rule cutting and creasing die;

FIG. 9 is a view showing the blank of FIG. 8 with certain of its side panels primarily folded, and glued in position, his view showing the blank as sold by the manufacturer to the user of the carton;

FIG. 10 is a fragmentary plan view drawn to a greatly enlarged scale showing a crosswise or transverse portion of the blank of FIG. 8 in the area indicated by the arrows 1010 and the associated broken lines, and with most of the main panel broken away;

FIG. 11 is a fragmentary view similar to FIG. 10 of a transverse portion of the folded blank of FIG. 9 indicated by arrows 1111 and the associated broken lines showing the inner side wall panels folded over and theglue panels or flaps glued to the main panel;

FIG. 12 is a sectional view at 1212 of FIG. 11;

FIG. 13 is similar to FIG. 12 but shows the folding of the side walls to upright position;

FIG. 14 is a fragmentary projectional view showing the hinge construction and hinge area of joined portions of the tray-type carton having parallel hollow triangular side walls and including a crosswise or transverse portion of the tray-like carton of FIG. 1 as indicated by the arrows 1414 and the broken lines associated therewith, but with most of the main panels of the two portions broken away. This is the same transverse portion as shown in FIGS. -13;

FIG. 15 is a view similar to FIG. 14 with the portions of the tray-type carton on opposite sides of the hinge area in partially folded position;

FIG. 16 is a section taken on line 1616 of FIG. 15;

FIG. 17 is a horizontal section taken on line 1717 of FIG. 15;

FIG. 18 is a view similar to FIGS. 14 and 15 with the portions of the carton on opposite sides of the hinge area completely folded at right angles to one another;

FIG. 19 is a section taken on line 19-19 of FIG. 18;

FIG. 20 is a section taken on line 20-20 of FIG. 19;

FIG. 21 is a section taken on line 2121 of FIG. 20;

FIG. 22 (sheet 4) is a view similar to FIG. 14 but showing the left-hand wall portions only and illustrating a variation of the hinge construction;

FIG. 23 is a view of the carton portions shown in FIG. 22 in partially folded position;

FIGS. 24 and 25 (sheet 5) are cross sectional views showing variations of the hollow triangular walls;

FIG. 26 is a fragmentary projectional view illustrating a still further variation of the hinge construction, this view corresponding to the central portion of FIG. 1 but with the main panels broken away in the lengthwise direction;

FIG. 27 shows the parts illustrated in FIG. 26 folded to final or closed position;

FIG. 28 is a fragmentary projectional view similar to FIG. 14 but showing the left-hand side wall only and illustrating a hinge immobilizer for cartons having inside web sections;

FIG. 29 is a projectional view showing the parts of FIG. 28 folded to their final position at right angles to each other;

FIGS. 30-36 illustrate hinge constructions wherein the web section is in the outer side wall panel of each hollow triangular side wall, instead of being located in the inside wall panel thereof;

FIG. 30 is a fragmentary projectional view similar to FIG. 14 showing the outside web hinge construction but drawn to a somewhat smaller scale;

FIG. 31 is a view of the carton portions shown in FIG. 30 in partially folded position, and is similar to FIG. 15;

FIG. 32 shows the carton portions in final position at right angles to one another, and is similar to FIG. 18

FIG. 33 shows the left-hand part of FIG. 30 for the purpose of illustrating a further variation of the outside web or linkage construction;

FIG. 34 is a view similar to FIG. 14 showing the outside linkage or web hinge construction including a hinge immobilizer;

FIG. 35 shows the carton parts illustrated in FIG. 34 folded at right angles to one another;

FIG. 36 is a section taken on line 3636 of FIG. 35;

FIGS. 37-42 illustrate variations in the linkage or web hinge construction and also variations in the carton side wall, corner and end structures;

FIG. 37 is a plan view of the upper left-hand portion of a blank including the related inside web hinge construction having one form of foldable end structure such as just referred to;

FIG. 38 shows a cross section of the side wall construction of FIG. 37 in erected position;

FIG. 39 is a view similar to FIG. 37 of the upper lefthand portion of a blank for an outside web or linkage hinge which includes an additional interior main panel and another form of foldable end structure;

FIG. 40 is a cross-sectional view of the side wall and a portion of the bottom of the blank of FIG. 39 when erected;

FIG. 41 is a view similar to FIG. 37 of a blank which when erected provides a hollow side wall of trapezium cross section having an outside web hinge; and

FIG. 42 is a cross-sectional view of the trapeziumshaped wall formed from the blank of FIG. 41.

Referring to FIGS. 1-3, in FIG. 1 there is illustrated a tray-like carton having three sections, portions or parts made up respectively by main or bottom panels 1, 2 and 3 interconnected as shown by crosswise hinge lines 21 and 22. Main panel 1 has hollow side walls 4 and 5, shown as being triangular in shape, and an end wall 6. Panel 2 has similar side walls 7 and 8, and panel 3 similar side walls 9 and 10 and an end wall 11. All of these walls have vertical inside panels and sloping outside panels (see FIGS. 14, 15 and 18). However, the angularity of these panels is a matter of choice in all forms of the invention. The reverse arrangement may be used, as in FIG. 24, or both walls may be sloped as in FIG. 25.

For convenience the part having panel 1 will be referred to hereafter as receptacle part or portion R, the section having panel 2 as intermediate or back part or portion B, and the section having panel 3 as cover part or portion C. However it will be understood that in making up cartons or containers from the tray-like carton of FIG. 1 the several parts or sections may be utilized for numerous different purposes not indicated by the terms receptacle, back and cover, these terms being used merely for convenience of description.

Because of the special telescoping hinge construction between the several parts of the tray-like carton shown in FIG. 1, and in enlarged detail in FIGS. 14, 15 and 18 and to be described presently, the cover and back parts C and B respectively can be folded as shown in FIG. 3 and then further folded to provide the closed carton shown in FIG. 2. In this closed condition the hinge area of back section or part B is telescoped with that of the receptacle part or section R, and in FIG. 2 these portions are disposed at right angles to each other in forming a mitered joint. Cover section C occupies a similar position with respect to back part B, and is parallel with the receptacle R. FIG. 2 shows that the apex of hollow Side wall 9 of cover C rests upon the apex of wall 4 below it on receptacle R. Similarly, the remaining side walls of the cover and receptacle parts rest apex-to-apex.

In order to hold the cover and receptacle portions in closed position a suitable closure device such as the closure strap 12 may be arranged on the end wall of cover C. This may be formed by a portion cut out of the inner wall of end wall 11, as indicated in FIG. 1, and then bent upwardly so as to project from the ridge of this wall. A tongue 13 may be formed in strap 12 and displaced inwardly from its surface. Tongue 13 will enter a slit 14 formed in the outside of end wall 6 of receptacle R by making a suitably shaped cut as shown in FIG. 1. Tongue 13 may be engaged in slit 14 when the carton is in the closed position of FIG. 2.

Also projecting from end wall 6 of receptacle R and the end wall 11 of cover C are pairs of projections which will be referred to as dentals 15 and 16. Their use is optional but advantageous. The pairs of dentals 16 of the cover C are spaced with respect to the pairs of dentals 15 of the receptacle so that when the cover is closed on receptacle R, the adjacent edges of these dentals engage one another as shown in FIG. 2. It will be understood that instead of, or in addition to, dentals 15 and 16, similar dentals (not shown) may be provided on the opposite side walls 4 and 5 of the receptacle section and 9 and 10 of the cover section.

By means of these dentals, or their equivalent, in conjunction with the construction of the special hinge means between back section B and receptacle R and cover C, cover C is firmly seated on receptacle R with their respective walls in contact with one another apex-to-apex, and they will be maintained in this position. Consequently such cartons can be safely stacked one upon another even when filled with heavy articles of merchandise.

In FIG. 3 it is indicated that the adjacent portions of the holow triangular walls at the hinge lines 21 and 22 engage or telescope one another as the back portion is folded with respect to the receptacle portion R and the cover portion C is folded with respect to back portion B, and when the carton is in the closed condition of FIG. 2 this telescoping produces a locking action between walls 4 and 9 and wall 7, also between walls 5 and 10 and wall 8. The interlocking of these walls at such points gives the carton great stability so that the ridge lines of the hollow triangular walls on the cover portion C are held apex-to-apex with the ridge lines of the hollow walls of receptacle section R, without the closure strap 12 and without the dentals 15 and 16.

By changing the dimensions of the various sections of the tray-like carton of FIG. 1 and also by changing the telescoping angles between adjacent sections when they are folded about their hinge lines, cartons of various configurations can be constructed as illustrated in the small scale FIGURES 47. Thus in the triangular shaped carton of FIG. 4- the wall at the left may be formed from the back section B of the tray-like carton of FIG. 1, the bottom being formed from the receptacle R, and the right-hand sloping section from cover section C. It will be understood that the hollow triangular walls at the upper and lower hinge lines are in fully telescoped relation to each other when the wall sections are folded to an angle of 60 with respect to one another instead of 90 as is the case with the carton of FIG. 2. The cover and tray sections of the triangular carton will close along the line 17, and the surfaces of the adjacent hollow triangular walls will be beveled along the line 18 so as to contact one another in this plane.

In FIG. 5, an L-shaped box, the horizontal portion corresponds to back section B of the L-shaped tray of FIG. 1, and the upright portion to cover section C. These two sections will be maintained at right angles to one another by hinge-immobilizing devices to be later described.

In FIG. 6, in which the carton has the shape of the letter C, the upright portion will correspond to the back section B of FIG. 1 having a considerably increased dimension longitudinally of its side walls. The lower portion of this box will correspond to receptacle portion R and the upper portion to cover portion C, these two portions being maintained in spaced and parallel relation.

Referring to FIG. 7, this carton has two section 19 and 20 which correspond to back section B, and its remaining sections correspond either to the receptacle portion R or the cover portion C of FIG. 1.

All four of these constructions lend themselves touse as counter display devices. In the devices of FIGS. 4 and 7 the carton can 'be partially opened for display purposes, and the devices of FIGS. 5 and 6 are particularly useful in shrink film packaging.

FIG. 8 of the drawings illustrates the blank from which the tray-like carton of FIG. 1 is made. Its unfinished inner surface is shown uppermost. The blank is subdivided into panels and flaps by a plurality of fold lines. Main panel 1 forms the bottom of receptacle R, panel 2 the back of back section B and main panel 3 is the principal panel of cover section C. Panel 1 is conected to panel 2 by means of the transverse hinge line 21, and panel 3 is connected to the opposite edge of panel 2 by crosswise hinge line 22 parallel to hinge 21.

Main panels 1, 2 and 3 are bordered by outer side fold lines 23 and 24 and by outer end fold lines 25 and 26. These fold lines intersect at the corners 27, 28, 29 and 30. Outer side wall panels 31 and 32 are articulated to main panels 1, 2 and 3 along the outer side fold lines 23 and 24 respectively. Inner side wall panels 33 and 34 are articulated to the outer side wall panels along side ridge fold lines 35 and 36. Reverse fold panels 37 and 38 are articulated to the inner side wall panels 33 and 34 along inner side fold lines 39 and 40 respectively. Glue flaps 41 and 42 are articulated to the reverse fold 6 panels 37 and 38 along fold lines 43 and 44. Each of these panels and flaps extends throughout receptacle section R, back wall section B and cover section C of the tray-like carton of FIG. 1.

In a similar manner outer end wall panels 45 and 46 are articulated to main panels 3 and 1 respectively along the outer end fold lines 25 and 26 respectively. Inner end wall panels 47 and 48 are articulated to the outer end wall panels along end ridge fold lines 49 and 50 respectively. Tuck flaps 51 and 52 are articulated to the inner end wall panels 47 and 48 along inner end fold lines 53 and 54 respectively.

The corners of the blank shown in FIG. 8 have flaps 55 and 56 at one end and 57 and 58 at the opposite end. In addition there are flaps 59, 60, 61 and 62, together with flaps 63, 64, 65 and 66, as well as flaps 67, 68, 69 and 70. Present also at the corners of the blank are corner fold lines 71, 72, 73 and 74, also corner lines 75, 76, 77 and 78. In addition there are flap fold lines 79, 80, 81 and 82.

These parts, and also the end panels on the fold lines referred to above are described in detail in my Patent No. 2,605,953, issued Aug. 5, 1952, and these or other suitable means in cooperation with glue fiaps 41 and 42, serve to maintain the tubular or hollow triangular side walls 4, 5, 9 and 10 of the carton of FIG. 1 in erected position.

The erection of the tray-like carton of FIG. 1 will now be described.

FIG. 10 shows a fragment or portion of the blank of FIG. 8 indicated by the arrows 10--10 and associated broken lines of FIG. 8, and FIG. 11 shows a similar section of the partially folded 'blank of FIG. 9 indicated by the arrows 1111 and associated broken lines of this figure. While the blank is in the flat condition of FIG. 8, glue stripes 83 and 84 are applied to glue flaps 41 and 42. Thereafter inner side wall panels 33 and 34, reverse fold panels 37 and 38, and glue flaps 41 and 42 are folded about the respective ridge fold lines 35 and 36 to their positions as shown in FIGS. 9, 11 and 12 and the glue flaps are adhered to the inner surface of main panels 1, 2 and 3. Flaps 67, 68, 69 and 70 at the opposite ends of inner wall panels 33 and 34 are folded simultaneously about the stipple cut lines shown in FIG. 8 as extensions of ridge fold lines 35 and 36.

The first step in the erection of the carton is the lifting of panels 31, 33 and 32, 34 (FIG. 13) so as to form the hollow side walls of the receptacle section R, the back section B and cover section C along the fold lines 23 and 24 respectively as shown by the curved arrows in FIG. 9. As such lifting takes place the blank bends along fold lines 23 and 24 as may be seen in FIG. 13. As the upward and inward lifting or swinging of these panels continues from the full line position of FIG. 13 to the dot and dash position, panels 33 and 34 forming the inner walls of the hollow side walls reach the vertical position, and reverse fold panels 37 and 38 are folded fiat against the upper surfaces of the respective glue flaps 41 and 42, as shown in FIGS. 13 and 24.

The flaps forming the end walls of receptacle section 1 and cover section 3 are now folded as referred to above and described in applicants prior patent. These end closure flaps engage the flaps at the ends of panels 31, 32, 33 and 34 as described in the patent and serve to maintain in fixed upright position the hollow triangular walls formed by panels 31, 32, 33 and 34. The adhesion of the glue flaps 41 and 42 to the respective bottom or main panels 1, 2 and 3 maintains the spacing of panel 31 with respect to panel 33 and of panel 32 with respect to 34 at the bases of the respective hollow side walls. The hollow triangular side walls are now held in fully erected position as shown in FIG. 1 and also in FIG. 14.

The special hinge construction by which these fully erected hollow triangular side walls are folded transversely despite their naturally strong three-dimensional resistance to such folding includes the interruption of one of the side wall panels at the hinge line and the provision in the other side wall panel of a generally triangular linkage or web section joining the portions of that panel on opposite sides of the hinge line. The generally triangular web or linkage section is composed of a plurality of triangular panels two of which are joined by fold lines to the respective wall panel portions on opposite sides of the hinge line, these fold lines radiating from the vicinity of the hinge line and the triangular panels being joined to each other by one or more fold lines.

By employing two triangular panels, one larger than the other they are made to co-act with the inner surfaces of the hollow triangular walls when the portiOns of these walls on the opposite side of the hinge line are folded relative to each other, and thus produce a frictional braking effect with which to control the folding action of the hollow walls. Specific embodiments of the invention wherein the web or linkage sections include two such unequal triangular panels will now be described in connection with FIGS. 8-36.

Referring first to FIGS. 8, 9 and 10, portions of the inner side walls 33 and 34 on opposite sides of crosswise hinge line 21 are interconnected by means of web or linkage sections indicated generally by numeral 85. Each of these web sections comprises two approximately triangular panels one somewhat larger than the other. The larger triangular panel is indicated by reference numeral 85L (FIGS. 8 and 10) and the smaller one by reference numeral 855. These two triangular panels have a common fold line 86 which, in this form of the inven tion, is in line with crosswise hinge lines 21 and 22 between main panels 1 and 2 thus effecting the difference in panel size.

Usually the carton will be made of paperboard, and the direction of the grain is indicated by the arrows in FIGS. 8 and 37. It is to be noted that the grain extends lengthwise of the wall panels containing the triangular panels and therefore crosswise of the common fold line between them.

The smaller triangular panel 858 has a fold line 87 joining it to the adjacent portion of inner side wall panel 33 at an angle extending obliquely with respect to the common fold line 86 and crosswise hinge line 21. The larger triangular panel 85L is similarly connected to the portion of panel 33 on the opposite side of hinge line 21. It has a fold line 88 which is also oblique but at a greater angle to hinge line 21 than fold line "87 so that it intersects the ridge fold line 35 at a point 89 which is at a greater distance from hinge line 21 and common fold line 86 than the point 90 where hinge line 87 intersects the ridge fold line 35.

The two fold lines 87 and 88 of the web section triangular panels extend obliquely from the opposite sides of and near the inner end of a wide slot 91 which is centered on hinge line 21 at each side of the blank. It is important for the best operation of web sections 85 that fold line 87 be stiffer than fold line 88, and this is indicated by showing fold line 88 as being stipple cut. The width of both triangular panels 85S and 85L is less than the width of panel 33 in order to facilitate the folding of web section 85 as will be described later on. The material of panel 33 from panel edges 93 and 94 to the ridge fold line 35 is removed and discarded.

Slots 91 extend from the inner margins of panels 37 and 38 (FIG. 10) across these panels and partially across panels 41 and 42 respectively, leaving short portions 92 at the marginal edges of panels 41 and 42 which serve to interconnect the portions of these respective panels which are on the opposite sides of fold hinge line 21. Short fold lines 21a and 21b are provided in the portions 92 in line with the side edges of slots 91. Slots 91 extend through and therefore interrupt the two glue stripes 83 and 84.

When panels 33, 37 and 41, and the corresponding panels on the opposite side of the blank are folded to the positions shown in FIG. 11, and glue flaps 41 and 42 are adhered to main panels 1, 2 and 3, slots 91 will overlie the end portions of binge fold line 21, and portions 92 will also overlie the adjacent portions of fold line 21. See FIGS. 11 and 14. Thus When portions of the tray-like carton on opposite sides of hinge line 21 are folded about this hinge line as shown in FIGS. 15 and 18 the short portions 92 bulge upwardly or inwardly as shown in FIGS. 14 and 15 and portions 92 together with slots 91 receive the upward bulging of the material along hinge line 21. Should slots 91 and short fold lines 21a and 2111 be omitted, the double thickness of material in the glue flaps 41 and 42, and the superposed panels 37 and 38 would cause the cracking of the material of the carton main panels 1 and 2 on the outside surface thereof and would seriously impair its appearance. While it is advantageous from the standpoint of machine gluing to keep panels 41 and 42 integral throughout their length slots 91 may be extended to the edges of these panels, if desired.

This completes the description of web sections interconnecting the end portions of the inner side wall panels 33 and 34 on the opposite sides of the crosswise hinge lines 21 and 22. The structure of the outer side wall panels 31 and 32 on the opposite sides of crosswise hinge line 21 will now be described.

Referring more particularly to FIGS. 10 and 14, and also to FIG. 8, panels 31 and 32 which form the outer side walls of the respective hollow triangular side walls of the carton are interrupted at the crosswise hinge line 21. The terminal portions 95 of walls 31 and 32 on one side of the hinge line are arranged to engage in sliding contact the terminal portions 97 of these walls on the opposite side of the hinge line as the two hollow triangular wall portions of each side wall on opposite sides of hinge line 21 telescope one another when main panel 1 is folded or bent about hinge line 21 with respect to the main panel 2 of the intermediate or back section B of the tray-like carton.

Terminal portion 95 has a sloping edge 96 opposite the larger triangular panel 85L of web section 85 and which extends from the intersection of fold line 23 of panel 31 and crosswise hinge line 21 (FIGS. 8 and 10) to the intersection point 89 where the edge 93 of triangular panel 85L intersects ridge fold line 35. The angle between edge 96 and hinge line 21 in the flat blank as shown in FIG. 10 is nearly the same as the angle of the stripple out or weaker fold line 88 by which triangular panel 85L is connected to inner side wall panel 33. The material of the blank between edge 96 and ridge fold line 35 and hinge line 21 is removed and discarded.

Terminal portion 97 on the opposite side of cross-hinge line 21 from terminal portion 95 has an abutment edge 98 which is in line with cross-hinge line 21 and therefore at right angles to the direction of the hollow triangular side walls of the carton. It also has an edge 99 at right angles to abutment edge 98 and parallel to and slightly spaced from the ridge fold lines 35 and 36 respectively.

After the hollow triangular side walls are erected as shown in FIG. 14 the sloping edge 96 of terminal portion 95 of each of walls 31 and 32 extends angularly from the intersection of these walls with the cross-hinge line 21 to the intersection point 89 of triangular panel 85L with each side wall. The abutment edge 98 of terminal portion 97 on the opposite side of hinge line 21 is in upright position in the vertical plane passing through hinge line 21 at right angles to main panels 1 and 2, while the edge 99 is parallel to main panels 1 and 2 and at or slightly below ridge fold lines 35 and 36.

In FIG. 15 the main panel portion 1 of receptacle portion R and main panel portion 2 of the intermediate or back portion B of the tray-like carton shown in FIG. 1, have been bent about cross hinge line 21 with respect to one another and this has caused the web sections 85 of each side wall to commence their folding action. In FIGS. 1 and 14- the triangular panels 85L and 858 of each of the web sections are in substantially the plane of the respective inner walls 33 and 34 of the hollow triangular side walls. In FIG. 15 these triangular panels 85L and 85S of each web section have been broken about their respective common fold lines 86 and the panel portions adjacent these fold lines have swung toward the interior of each of the hollow triangular walls. Thus in FIG. 15 the common fold line 86 of the left-hand hollow wall has moved in a leftward direction, whereas the fold line 86 of the right-hand hollow wall has moved toward the right.

In converting the tray-like carton from the condition of FIG. 1 to the position of FIG. 3, in order to insure that these web sections fold inwardly as just described, the common fold lines 86 of all four web sections 85 of FIG. 1 and fold lines 87 and 88 are broken inwardly either mechanically or manually. Thereafter, because fold lines 88 of the larger web panels are weaker than. fold lines 86 and 87 the web sections will automatically fold in the correct directions.

As shown in FIG. 15 the terminal portions 97 of each side wall have begun their sliding engagement with the terminal portions 95 on the opposite side of hinge line 21. This movement will continue until the edge 98 of each terminal portion 97 rests against the bottom surface of each triangular side wall as shown in FIG. 18. A portion of each of these surfaces has a multi-thickness layer inasmuch as it consists of the reverse fold panels 37 or 38, the glue flaps 41 or 42 and the main panel 1 and therefore provides a firm support for terminal portion 97. At the same time the two ridge fold lines 35 and 36 are brought into firm engagement with the intersection points 89 (FIG. 18) previously referred to, at the tops of the respective triangular side walls on the opposite side of hinge line 21, that is, on back section B and receptacle section R.

The telescoping of the end portions of the hollow triangular side walls on the back section B with the end portion of the corresponding walls on the receptacle portion R is possible because of the fact that the intersection points 90 on the side walls of the back section B are closer to the vertical plane through hinge line 21 than the intersection points 89 of the side walls of the receptacle portion R. This may be seen from FIG. 10, intersection point 90 being associated with the small triangular panel 858 and intersection point 89 with panel 85L. Because of this points 90 are closer to hinge line 21 than points 89 as indicated in FIG. 15 and shown in FIG. 16 which is a transverse section taken on a plane at right angles to the right-hand hollow triangular wall of back section B.

The terminal portions 97 must always telescope on the inside of the terminal portions 95 and this is accomplished by exerting pressure either manually or mechanically against the outer surfaces of the hollow triangular wall sections of the back section B. The direction of this pressure is indicated by the arrow in FIG. 17 showing the correct location of terminal portion 97 with respect to terminal portion 95. This figure also shows the initial folding of the triangular panels 85L and 85S which are shown in the position corresponding to the right-hand portion of FIG. 15.

During the folding of the carton sections to the position of FIG. 18 from the position of FIG. 15, the triangular panels 85S and 85L fold closer to one another about their respective fold lines 87 and 88 and their common fold line 86 until these triangular panels are substantially in contact with each other and the larger panel 85L of the right-hand hollow wall is folded substantially 180 about fold line 88 and fiat against the inner surface of side wall 34 and panel 85L of the left-hand hollow wall is against side wall 33. The panels 85S and SSL are shown in these positions in FIG. 18, and in the sectional views in FIGS. 19, 20 and 21.

The telescoping of the hollow triangular walls at the hinge line imparts stability and ruggedness to any carton to which the invention is applied. Such characteristics are 10- particularly apparent in a box of the type shown in FIG. 2, sometimes referred to as a book form of box. The stability results in part from the frictional engagement of the parts of the web sections with respect to one another and with the inner panels of the hollow walls,

as well as through the inter-engagement of the terminal portions and 97 of the outer wall panels.

The telescoping of these hollow wall portions on opposite sides of both hinge lines 21 and 22 serves to hold the ridges of the hollow walls in apex-to-apex contact. They are maintained in such direct, firm engagement that the triangular walls are themselves prevented from telescoping with respect to one another. They have good stacking strength similar to that of conventional cartons. Moreover, considerable economy is eifected over the usual telescoping walls of the receptacle and cover portions of conventional cartons.

FIGS. 22 and 23 (sheet 4) show a variation in the construction of the web sections 85, these figures corresponding to FIGS. 14 and 15, respectively, but showing only the left-hand triangular wall portions. In this variation a shoulder is arranged on the edge 93 of triangular panel 85L at any desired location. Shoulder 100 may be produced in any convenient manner, as for example, by means of a notch in the edge 93, or as shown in FIG. 22 by lowering the edge 94 of triangular panel 855 at the point where it intersects fold line 86 or by suitably curving the edges of the triangular panels as shown for example at 144 in FIG. 37.

The purpose of shoulder 100 is to insure that the larger triangular panel SSL is folded through an angle of approximately when the carton parts have been folded about the hinge line 21 and have reached the position corresponding to FIG. 15. This is accomplished by the engagement of the edge 98 of terminal portion 97 with shoulder 100 during the folding operation about hinge line 21. It is indicated in FIG. 23. The pressure of edge 98 against shoulder 100 forces the larger panel 85L to the right through an angle of approximately 180 or until this parallels against the surface of wall 33.

In addition, the folding of panel. 85L by the pressure of shoulder 100 swings this panel against terminal portion 95 at the proper time to cause portion 97 to telescope inside of portion 95.

It will be understood that the hollow triangular walls may be made in other forms than illustrated in FIGS. 1-23 in which the inner walls 33 and 34 are vertical. Thus, FIG. 24 shows in section a right hand hollow triangular wall in which the outer wall panel 32a is vertical instead of sloping as shown in FIG. 16 and the other FIGS. 1-23. In the variation of FIG. 25 inner side wall 34b and outer side wall 32b both slope.

Referring now to FIG. 26 (sheet 7) there is here shown a variation in the inside web hinge construction which renders the parts of the carbon easier to fold but without detracting from its appearance. FIG. 26 shows the central portion of the carbon corersponding to the back portion B and parts of the receptacle and cover portions R and C of FIG. 1. However, instead of the inside wall panels being vertical, both wall panels slope as in FIG. 25. The web sections 85 are identical with those shown in the previous figures and previously described. The

same reference numerals have been used but with the subscript b applied to the numerals that are common to the previous figures. The terminal portions 97b of the outside wall panels of the hollow, triangular walls are also the same as described previously.

The construction of FIGS. 26 and 27 features the addition of a guide flap 101 to each of the wall hinge structures. Such guide flap is hinged by a crease line 102 to the terminal portions 95b of the outside wall portions which are opposite each of the terminal portions 97b.

In the operation of setting up the carton from the tray-like condition of FIG. 26 to the form shown in FIG.

27, for example, the guide flaps 101 are bent outwardly along their fold lines either manually or mechanically. Thereafter, they remain in a somewhat outwardly projecting position. Consequently, when any carton portion, such as the receptacle portion R, is folded about hinge line 21b with respect to the back portion B, the terminal portions 97b are directed by the guide flaps 101 towards the inside of each of the terminal portions 95b, so that the cooperating wall sections correctly telescope one within the other.

In a similar manner the cover portion C can be folded about its hinge line 22b with respect to the back portion B so that the cover portion and receptacle portion are in contact wtih one another along the respective ridgefold lines of their hollow, triangular side walls as shown in FIG. 27. The carton may be opened either partially or completely as shown in FIG. 26, and then reclosed as often as desired, and the portions of the hollow, triangular side walls on the opposite sides of the two hinge lines 21b will telescope properly with respect to one another.

This carton may be closed by folding the receptacle and cover sections R and C about the respective hinge lines 21b and 22b to form a closed or booklike carton as shown partially in FIG. 27 and quite similar to the carton of FIG. 2. The sections of the hollow side walls of the carton opposite each of the hinge lines telescope one another and thus hold the ridge fold lines 35b and 36b in contact apex-to-apex, the same as with the construction of FIGS. 1-3. The flap guides 101 lie close against the sloping surfaces of the outer panels of the side walls of the intermediate section B, and present a neat appearance.

In FIGS. 28 and 29 there is shown a device by which any of the hinge constructions previously described can be immobilized, so that the hinged carton parts are secured in the desired position relative to each other.

In FIG. 28 a hollow, triangular side wall construction is shown on only the left side of the portions of the receptacle section R and back section B on opposite sides of the hinge. A web section 85b is arranged in the inner panel of the side wall as described previously, and projecting from the sloping edge 96b of terminal portion 95b of the outer wall panel, there is a hook-shaped member 103. The point 104 of this hook member extends upwardly towards the ridge-fold line 35b.

In the outside wall panel portion 97b on the opposite side of the hinge line a slit 105 is cut at an angle to the bottom of the hollow, triangular wall, such that when the carton sections on the opposite side of the hinge line, are folded into the right-angle position as shown in FIG. 29, hook member 103 will enter slit 105 and engage its upper edge. This looks the two sections at right angles to one another and immobilizes the hinge. To facilitate such engagement, a second slit 106 is cut at right angles to slit 105.

The construction just described is important in connection with numerous forms of the carton, such as those shown for example in FIGS. 5, 6 and 7. In a carton such as shown in FIG. 5, it is often desirable to place merchandise which may have considerable weight in the upright section. It will be understood that the upright section corresponds to back section B in the description of FIGS. 28 and 29, and consequently the hinge-immobilizing device will maintain the upright section of FIG. in position, so that the carton may be placed on a display counter without danger of any change in the angular relationship of the two sections with respect to each other.

The carton constructions of any of the previous figures in which the web sections 85 or 85b are in the inside panels of the hollow side walls, are advantageous wherever the setting up, formation or assembly of the cartons starts with the tray-like carton of FIG. 1 and is done manually. The pre breaking of the web sections in the right directions is very easily accomplished. However the setting-up operation can be done mechanically where the quantity of cartons warrants the provision of settingup apparatus.

FIG. 30 shows a section of tray-like carton as shown in FIG. 14, that is, a portion of receptacle section R and a portion of back or intermediate section B connected by a cross hinge line 21c between their main panels 10 and 2c. In this construction however, the web section, instead of being in the inside wall panel of each of the hollow triangular side walls, is in the outside wall panel of these walls, and is identified by numeral 107. Like the inside web structure the outside web structure 107 consists of two triangular panels one larger than the other and identified as 108L and 1085.

These panels are joined by a common fold line 110 which corresponds with fold line 86 of the inside web structure. Also panel 108L is joined to outer side wall panel 31c by means of a stipple cut fold line 109, and panel 1085 is joined to panel 31c on the opposite side of hinge line 21c by means of a stiffer continuous fold line 109x. Fold line 109x (FIG. 31) for the smaller triangular panel 1088 and the common fold line 110 between the two triangular panels may be made stiffer than fold line 109 of the larger panel 108L for the same reason as before, namely, so that once these fold lines are broken in the right direction the web section will thereafter fold correctly and automatically.

In FIGS. 30-32 the force to swing panel 108L through an angle of nearly 180 against the surface of wall panel 310 is applied to a shoulder 111 provided on panel 108L which is engaged by the vertical edge of terminal portion 97a of the inside wall panel 330 on the opposite side of hinge line 21c. Such engagement occurs when the two carton sections R and B are folded about hinge line 21c first to the position shown in FIG. 31 and thereafter to the right angular position of FIG. 32. During this folding movement terminal portion 97a telescopes and slides along the inner surface of the terminal portion a which is on the same side of hinge line 21c as triangular panel 108L.

As receptacle portion R and back portion B are folded about hinge line 210 the swinging of small triangular panel 108$ moves inwardly from its position shown in FIG. 30 panel 108L and its shoulder 111 into the path of the edge of terminal portion 97a. It also swings the upper edge of panel 108L into contact with the inner surface of terminal portion 95a pushing it towards the center of the carton and out of line with terminal portion 97a. Thereafter the continued folding about hinge line 21c causes the swinging of panel 108L through substantially 180 a previously mentioned so that it rests against the interior surface of wall panel 31c when the back section B reaches the upright position of FIG. 32 at right angles to receptacle R, and ridge 35 engages intersection point 89a. A neat mitered joint is produced.

In the above description of FIGS. 30-32 the outside web construction has been described in connection with the left-hand hollow triangular wall only. It will be understood that the same construction is repeated in the righthand hollow triangular wall consisting of sloping outside panel 32c and vertical inside panel 34c.

The outside web construction shown in FIG. 33 is similar to that just described except that the shoulder 111 (FIG. 30) is omitted. FIG. 33 shows the hollow triangular wall construction on the left side only of a half width carton section similar to that of FIG. 30. The larger triangular panel 112L and the smaller triangular panel 1125 are similar to the panels 108L and 1088 except that panel 112L has no shoulder for the engagement of the vertical edge of terminal portion 97a when the sections R and B are folded with respect to one another as described in connection with FIGS. 30-32.

The two triangular panels 112L and 1125 are interconnected by a common fold line 113 which like common fold lines and 86 previously referred to, lie in a vertical plane passing through the hinge line, such as hinge line 21c, when the two sections are in the fiat tray-like condition of FIG. 33. Panel 112L is hinged to sloping outer side wall panel 31c by means of a stipple cut 109, the same as in FIG. 30, and panel 1128 is connected along a continuous fold line 109x to the same panel but on the opposite side of the crosswise hinge line 210.

In folding the receptacle portion R with respect to intermediate or back portion B of either the form shown in FIG. 30 or that shown in FIG. 33, for the first time, the panels 108L and 1088 as well as the panels 112L and 1128 are to be forced inwardly to break or soften the fold lines 109, 109x, 110 and 113. This can be accomplished mechanically by means of a special folding finger so that cartons having the outside web construction are particularly adapted to be set up by machine.

Cartons having the outside web construction have an especially neat appearance because the terminal portions 95a and 97a of the wall panel which is interrupted at the hinge line are located on the inside of each of the hollow triangular walls, and also because guiding flaps if used to facilitate the telescoping of these terminal portions are also located on the inside so that they are not exposed to view. With cartons having the outside web construction the appearance of a miter joint is provided by the fold line 109 as shown in FIG. 32, when the triangular webs 108L or 112L have been folded or turned through an angle of 180 and lie against the inner surfaces of the outside panels 310 and 32a of the two hollow triangular side walls.

It will be understood that the hinge construction of the invention can be employed to maintain the carton sections at any desired angle with respect to one another for display purposes. Thus for example the cover section C and the back section B of FIG. 3 may be placed in any desired angular position with respect to receptacle portion R, and the hinge construction will maintain the parts in such positions. Friction between the interengaging telescoping sections of the hollow triangular walls such as the terminal portions 95 and 97, and the friction of the partially folded web sections such as 85, 107, 112, and 115 with these terminal portions serves to hold the carton sections in the angular positions to which they have been placed.

FIGS. 34-36 illustrate a device for immobilizing the hinge of a carton having the outside web hinge construction so as to maintain the parts on the opposite sides of the hinge fixed in position at right angles to each other as shown in FIG. 36. Such a construction is especially useful in forming cartons such as shown in FIGS. 5, 6 and 7. The hinge construction illustrated in FIGS. 3436 does not include the shoulder 111 (FIG. 30) but this shoulder may be included if desired.

Referring to FIG. 34 this shows a tray-like carton fragment similar to that of FIG. 14 but embracing portions of back section B and cover section C on opposite sides of cross-hinge line 22 (instead of hinge line 21) as indicated by the arrows 114 and the associated broken lines in FIG. 1. The two hollow triangular side walls have sloping outside wall panels 31d and 32a, and also inwardly sloping inside wall panels 33d and 34d, instead of the vertical inside wall panels shown in FIGS. 30-33. Here -again the angularity of the wall panels is a matter of choice.

The two sections of the outside wall panels 31d and 32d on opposite sides of the crosswise hinge line 22 are interconnected by a web section 115 consisting of large and small triangular panels 115L and 1158 which are interconnected by a common fold line 116. Also panel 115L is joined to panel 31d along a stipple cut fold line 117 and panel 1158 along a continuous, stronger fold line 118.

The inside wall panels 33d and 34d of the hollow triangular side walls are interrupted as before at the hinge line 22. The portions of these side walls on the intermediate or back section B have terminal portions 119 and the portions of these panels 33d and 34d on the cover section C terminate in triangular flaps 120, connected to their respective panels by continuous fold lines 14 121. At the ends of flaps there are tabs 122 connected by fold lines 123.

At the fold line 124 (FIG. 34) between the bottom edge of inner wall panel 34d and reverse fold panel 125 a U-shaped cut 126 is made so that when reverse fold panel 125 is folded about line 124 a short but wide projection or lug 127 is formed which lies against the upper surface of glue flap 128. These parts are shown at the right in FIG. 34 and they occur also in the left-hand hollow triangular wall although they are not visible in the drawing. Glue flap 128 is glued to the upper surface of main panels 2 and 3 but reverse fold panel 125 is not glued to the upper surface of glue flap 128. Hence when the cover portion C is folded about hinge line 22 to the upright position shown in FIG. 35, its hollow triangular side walls and those of the back portion B telescope with respect to one another.

In this upright position the tabs 122 of flaps 120 may be bent at right angles and tucked beneath the projections 127 and between reversed fold panels 125 and the upper surfaces of glue flaps 128. An incision has previously been made in the fold line 129 of glue flap 128 so that the tips of tabs 122 can project beyond the fold lines 129. U-shaped cuts 130 are also made in the flaps 120 at fold lines 123 so that when tabs 122 are bent about these fold lines, projections 131 are formed, and these projections are received beneath projections 127 as may be seen in FIGS. 35 and 36. In this 'way the tabs 122 are securely held by friction between the surfaces of the reverse fold panels 125 and glue flaps 128, and cover section C is securely locked in its upright position with respect to its intermediate back section B. In other words, the hinge construction is immobilized.

It will be understood that the carton construction shown in FIGS. 34-36 is especially useful in the construction of cartons having the shapes shown in FIGS. 5, 6 and 7 and wherein merchandise of some weight is to be mounted within the upright portion corresponding to the cover portion C of FIGS. 34-36. It is often desirable to open the cartons and place them on a shelf or counter so as to display the contents, and, with this construction, the upright section is secured firmly in position with respect to the horizontal or base section.

Reference will now be made to FIGS. 37-42 which show further variations in the linkage or web sections and in the cross sections of the hollow walls. In all of these figures the free edges of the linkage or web sections are in the form of a compound or reverse cur-ve instead of being straight.

In FIGS. 37 and 38 is shown the upper left-hand corner of a blank for an inside web carton having a sloping outside wall and vertical inside wall. The blank has a panel 2d for the intermediate or back part B of the carton and a main panel 3d for the cover part C, these panels being interconnected by a crosswise hinge line 22d. The panels are bounded by outer side fold lines 230., only the lefthand line being shown and by end fold lines 25d, only the upper fold line being shown.

At the left portion of the blank there are panels forming the hollow triangular wall section shown in FIG. 38. These comprise an outside wall panel 31d and an inside Wall panel 33d which are interconnected by a ridge fold line 35d. Joined to the outer wall panel 33d along a fold line 131 there is a side wall spacer panel 132 (FIG. 38), which serves, without gluing, to space the foot of inner wall panel 33d at the proper distance from the foot of the outer sloping wall panel 31d.

Interconnecting the portions of inner side wall panel 33d on the opposite sides of hinge line 22d there is a linkage or web section 85d. This is similar to the web sections previously described for the inside web structures except that the upper points of the triangular panels are blunted as shown and do not extend to the ridge fold line 35d, and the common fold line 860 is not in line with the hinge line 22d but is at an angle thereto so as to make the two triangular panels 143 of about equal size. In a dition the free edges 144 of these two panels are in the form of a compound curve and the Width of the triangular panels along the common fold line 860 is less than the spacing of wall panels 31d and 33d at the level of the free edge of the triangular panels 143 at fold line 860.

By having these panels narrowed in this way at the common fold line and also having their outer ends blunted the hollow walls 31d and 33d (FIG. 37) will not be pushed outwardly when the hollow walls are folded and the frictional resistance of folding is relieved. In addition if a tray insert is placed in a book-like carton such as shown in FIGS. 1 and 2 the hollow walls will not interfere with the edge of the tray insert during closing of the carton.

The outer wall panel 31d is interrupted at hinge line 220. as in the previous figures and the construction is as previously described including a guiding flap 10111.

The end and corner construction of FIG. 37 is the same as previously described in connection with FIG. 8, and the same reference numerals have been applied to the respective flaps and fold lines so that an understanding of this structure will be had from the previous description and also from the applicants prior Patent No. 2,605 953 previously referred to. However, any suitable structure may be used.

In the carton construction just described (FIG. 38) the side wall spacer panel 132 is not glued to panels 2d and 3d and the hollow triangular wall is maintained in upright erected position solely by the corner and end construction. As mentioned, FIG. 37 shows only the upper left-hand corner of a blank. This structure is repeated at each of the other three corners and a supporting structure is thereby provided at each end of each of the hollow triangular side walls for holding them in erected position.

In the foregoing description (FIGS. 1-36) the web sections 85, 107, 112 and 115 have been described as being comprised of two triangular panels each. However, these web sections need not be limited to having only two panels and may comprise three or more triangular panels interconnected by hinge lines and functioning in substantially the same way as heretofore described, but with what might be described as a rolling action as the carton parts are folded about the respective cross hinge lines 21 or 22.

FIGS. 39-40 show such a form of blank in which the web section 85e, instead of being made of only two triangular panels is composed of a plurality of these panels. This web section is in an outside wall, but it may be also used in an inside wall. The triangular panels include one large panel 145 which is connected to the side wall 31:; by means of a strong rather than a weak fold line. The remaining triangular Panels 146 (shown as four in number) are connected to one another by means of weaker fold lines and the terminal triangular panel is connected to wall panel 31e by a weaker fold line, all of these latter fold lines being shown as stipple cut lines. The free edge of this web section is a compound curve similar to FIG. 37.

FIGURES 39 and 40 also show a bank in which the hollow triangular side walls are of the shape shown in cross section in FIG. 40 where both the inner and outer panels are sloping and the web section is in the outside wall panel.

In this construction the carton has a double bottom. The outer and inner side wall panels 3-1e and 33a are of equal width and are bounded by fold lines 23e and 131e, the two panels being joined at their centers by ridge fold line 35e. The two panels 22 and 3e are joined by a crosswise hinge line 22e. The web section 85e is shown as being equivalent to the web sections described in connection with FIG. 33, although web section 85d of FIG. 37 may be used if desired.

An additional panel 133 which forms the double bottom is joined to the inner side wall panel 33 along fold line, the outer side Wall panels having oppositely 16 folded as shown in FIG. 40 panel 133 resting on top of main panels 2e and 3e.

The corner and end structure of the blank of FIG. 39 is similar to that shown and described in the applicants prior Patent No. 2,522,325 issued Sept. 12, 1950. At the end of the main panel 3e and secured thereto by a fold line 134 there are three panels in series indicated by numerals 12a, 12b and 13. Joined to the ends of outer and inner side wall panels 312 and 33a are two panels 12s and 12f, these panels being interconnected by a fold line 16a. Also a fold line 135 crosses panel 12e as an extentsion of ridge fold line 35a. These panels and flaps and their associated fold lines are described in detail in applicants patent just mentioned and these are the means by which the opposite ends of the hollow triangular side walls of the carton are maintained in erected position, but here again any suitable structure may be used for this purpose.

FIGS. 41 and 42 show a blank for forming an outside web carton having a hollow side wall having the cross section of a trapezium. This blank has main panels 2 and 3f interconnected by a crosswise hinge line 22f, and an outer side wall panel 136 which is joined to panels 2 and 3f along a fold line 137.

In this trapezium structure the inner wall is composed of an upper panel 138 and a lower panel 139. Panel 138 is joined to outer sidewall panel 136 along a ridge fold line 35 and the two inner side wall panels are joined together by common fold line 140. The lower inner side wall panel 139 has projecting therefrom along a fold line 141 a spacer panel 142. This spacer panel (FIG. 42) serves to maintain the lower inner wall panel 139 in properly spaced relation to the outer edges of main panels 2 and 3 The end wall and corner construction of the carton formed from the blank shown in FIG. 41 corresponds to those of FIG. 8 except for changes required by the trapezium walls which have four panels instead of three. The extra panel for the inner wall of the end hollow wall is shown at 47a. Like reference numerals have been placed upon the flaps and tabs.

In this form of carton the web section is in the outside wall 136 and serves to connect the two portions of this wall which are on opposite sides of the crosswise hinge line 22 This web section 85 may be formed as described in connection with either FIG. 33 or FIG. 39.

'It will be understood that the contour of the various angular shaped panels of the blanks both at the corners and in the web sections at the hinge lines may vary substantially from the specific shapes shown in the drawings, as for example, the shape of the corner panels 55, 59, 63 and 67 and the web section panels of FIGS. 37, 39 and 41, as compared with the corresponding panels of FIG. 8.

In the forms of the invention described above in connection with FIGS. 1-42 the end portions of the hollow triangular side walls of the intermediate or back section B telescope into the end portions of the hollow triangular side walls of the receptacle and cover sections R and C. This is, however, not necessary and the reverse arrangement may be employed if desired. That is to say, the end portions of the side walls of the receptacle and cover portions R and C may be arranged to telescope into the end portions of the side walls of the intermediate or back section B. The choice depends upon the type of carton which is to be the end product, and also on the angles chosen for the fold lines of the small and large triangular panels of the web section with respect to the main panels.

Thus, if the book form of box shown in FIG. 2 is to be the end product it is desirable, if not necessary to provide comparatively long ridge fold lines 35 and 36 for the back or intermediate section B. It is therefore desirable to have the angles of fold lines 87 for the small triangular web panels with respect to the main panel 2 relatively large. With these angles relatively large the angles of the fold lines 88 of the large triangular panels with respect to main panels 1 and 3 will be correspondingly small. By way of example, the former might be 60 and the latter 45 (FIG. 8). Such relative angles will bring about the telescoping ofthe walls of the back section B into the walls of the receptacle and cover sections R and C.

As mentioned in the description and shown in the drawings, the common fold lines such as 86, 110, 113 and 116 between the two triangular web panel sections are stated to be in a plane passing through the crosswise hinge lines 21 or 22 when the carton sections are in the tray-like form of FIGS. 1, 26, 30 and 34. This however is not essential to the proper functioning of the hinge construction, and these fold lines may be angled either to one side or the other of such a plane (FIGS. 37 and 41), depending upon the particular carton which is to be the end product. For example, if the book-like box of FIG. 1 were to be used for confectionery, a removable tray might be included which would fit snugly the receptacle part of the carton. The side walls of such a tray might interfere with the proper operation of the web sections of the cover part C if the common fold lines between these web sections were vertical thereby making the web section unequal. By arranging the common fold lines at an angle to make the web section equal such interference would be avoided.

In making up a package of merchandise, should it be desired to use shrink film, the hollow triangular side wall construction is especially useful because of its inherent strength and resistance to the draw of the shrink film. Cartons of the type shown by way of example in FIGS. 4, and 6 can be used successfully with shrink film. In the structures of both FIGS. 5 and 6 the hinge locking or immobilizing devices, one of which has been described in connection with FIGS. 28 and 29, and another with FIGS. 34 and 36, are especially helpful when shrink film is applied.

I claim:

1. A tray-like structure formed of foldable sheet material =having a flat bottom panel divided into at least three parts by at least two transverse hinge lines and having at opposite sides of each of said hinge lines aligned hollow wall portions of polygonal cross-section, said hollow wall portions each comprising a plurality of panels at least one of which is interrupted at its intersections with said transverse hinge lines, and another of said wall panels having a plurality of transverse fold lines defining a flexible linkage section interconnecting the portions of said other wall panel on the opposite sides of the hinge line at each of said intersections with the hinge lines, thereby enabling the thus integral-walled tray-like structure to be folded transversely at said bottom panel hinge lines.

2. A tray-like carton including a main panel having hollow triangular side walls and crosswise hinge means dividing the panel and its side walls into at least two portions, the hollow triangular wall portions 'having 00- operating flexible linkages at said hinge means thus enabling the hollow wall portions to be foldable into telescoping relation for forming a mitered joint between the hollow triangular wall portions on opposite sides of the hinge means when the panel and side wall portions are folded at an angle to each other.

3. A tray-like carton 'as set forth in claim 2 wherein the inside wall panel of each hollow triangular side wall is secured to the main panel.

4. A tray-like carton as set forth in claim 2 in which one side of each hollow triangular side wall is interrupted at the hinge means and the terminal portions thereof on opposite sides of the hinge means engage one another in sliding contact as the two hollow triangular side wall portions telescope each other, and also wherein the flexible linkage of the other side of each of the hollow triangular side wall portions include a linkage section interconnecting such wall portions on the opposite sides of the hinge means, said linkage sections co-operating with said terminal portions and facilitating the telescoping engagement thereof.

5. A tray-like carton as set forth in claim 4 wherein the linkage section of each of the hollow triangular side Walls comprises at least two triangular panels having a fold line therebetween, one of said triangular panels being larger than any other, and two of said panels each having a fold line extending from said crosswise hinge means and joining it to one of the wall panels of the hollow triangular side walls.

6. A tray-like carton as set forth in claim 5 wherein the fold lines for the two triangular panels which join said panels to one of the side wall panels extend obliquely to the base of the said wall panel, the angle of the smaller triangular panel with respect to said base being greater than the angle of the larger triangular panel thereby causing the hollow wall to which the small triangular panel is connected to telescope within the hollow Wall to which the larger triangular panel is connected.

7. A tray-like carton as set forth in claim 5 wherein the point of at least one of the triangular panels terminates short of the ridge fold line thereby reducing the resistance of the triangular panel to folding about its oblique fold line.

8. A tray-like carton asset forth in claim 5 in which the linkage section comprises two triangular panels having a fold line therebetween, said fold line lying out of alignment with the hinge means.

9. A tray-like carton as set forth in claim 5 in which the linkage section comprises two substantially triangular panels, the free edges thereof being reversely curved.

10. A carton as set forth in claim 5 wherein a shoulder is provided in one triangular panel of each web section at the top of the fold line thereof with the adjacent panel, the terminal component of the opposite sides wall having an abutment edge which engages said shoulder during the swinging of the carton portions into telescoping position and causes the triangular panel to swing to final position.

11. A tray-like carton as set forth in claim 4 wherein the inside wall of each hollow triangular side wall has at its foot a spacer panel the edge of which engages the base of the outer wall of said side wall, and also wherein means is provided at the opposite ends of the hollow triangular side walls for maintaining said Walls in erected position.

12. A tray-like carton as set forth in claim 4 wherein the linkage section of each of the hollow triangular side walls comprises a plurality of triangular panels two of which are joined by fold lines to the respective side wall panels on opposite sides of the hinge line and the several triangular panels being joined to each other by one or more fold lines, all of said fold lines radiating from the vicinity of the hinge line.

13. A tray-like carton as set forth in claim 4 wherein the terminal portions of the hollow side walls which engage one another in sliding contact include a hook member on one terminal portion and a slit in the other terminal portion which are engageable with each other when the side wall and main panel portions are folded at right angles to each other thereby maintaining said portions in such position.

14. A tray-like carton as set forth in claim 4 wherein one of the terminal portions of each of the hollow side Walls which engage one another in sliding contact has a projecting flap which has a foldable tab near the end thereof, such tab being bent at an angle to the flap and inserted and frictionally held beneath the foot of the side wall on the opposite side of the hinge means when the side wall and main panel portions are folded at an angle to each other, said flaps and tabs maintaining said portions in such position.

15. A re-closable box having a receptacle part and a cover part each having a hinged joint with an intermediate back part, the said three parts each having hollow side walls of polygonal cross-section which meet at one of the hinged joints, the receptacle and cover parts each also having front walls, the said side and front walls of the receptacle and cover parts of the box, when closed, bearing directly upon one another in non-telescopic relationship, and the said hollow walls of the back part being in telescopic mitered relation with the rear ends of the thus disposed hollow side walls of the closed box.

16. A pre-cut and creased blank for forming a hollow walled foldable carton comprising a series of main panels interconnected by parallel spaced hinge lines, outer side wall panels joined to the sides of the main panels along first side fold lines respectively, an inner side wall panel joined to each outer side wall panel along a side wall ridge fold line, a reverse fold side wall panel joined to each inner side wall panel along a third side fold line, a glue flap articulated to each reverse fold panel along a fourth fold line, said glue flaps having glue stripes extending lengthwise thereof intermediate their side edges, said reverse fold panels and glue flaps having slots therein in line with the hinge lines, each of said slots near one end interrupting the adjacent glue stripe and extending at its opposite end into the adjacent inner side wall panel, said slots being of sufiicient width so that when the reverse fold panels are folded to overlie the glue flaps and the glue flaps are adhered to the surfaces of the main panels and the blank is folded at the hinge lines, slack will be provided in the material of the glue flaps above the hinge lines, and the material of the blank on the opposite side will thus not be cracked.

17. A pre-cut and creased blank for forming a hollowwalled foldable carton as set forth in claim 16 wherein said slots are closed at both ends leaving a connection between the outer margins of the glue flaps on the opposite sides of each hinge line, and a small crease on each side of each such connection.

18. A pre-cut and creased carton blank as set forth in claim 16 wherein triangular areas forming linkage or web sections are provided between each of said slots and the end of the corresponding hinge line.

19. A pre-cut and creased blank for forming a hollowwalled foldable carton comprising a series of main panels interconnected by parallel spaced hinge lines, outer side wall panels joined to the sides of the main panels along first side fold lines respectively, an inner side wall panel joined to each outer side wall panel along a side wall ridge fold line, the outer side wall panels having oppositely facing generally triangular apertures having their respective apexes at the respective ridge fold lines, the bases of such triangles opposite the apexes being approximately in line with the respective hinge lines, and the inner side wall panels each having at each hinge line at least two generally triangular web sections whose side edges radiate from the 20 vicinity of the hinge line near the outer edge of the panel, said sections being joined by a common fold line which lies approximately on an extension of the hinge line.

20. A pre-cut and creased blank for forming a hollowwalled foldable carton as set forth in claim 19 made of paperboard and having the direction of grain crosswise of the web sections and substantially at right angles to the common fold lines of said web sections.

.21. A pre-cut and creased blank for forming a hollowwalled foldable carton comprising a series of main panels interconnected by parallel spaced hinge lines, outer side wall panels joined to the sides of the main panels along first side fold lines respectively, an inner side wall panel joined to each outer side wall panel along a side wall ridge fold line, the inner side wall panels each having at each hinge line at least two generally triangular web sections whose side edges radiate from the vicinity of the hinge line and the outer edge of the panel, said web sections being joined by a common fold line which lies approximately on an extension of the hinge line, the web sections having free edges which are spaced from said ridge fold line, and each outer side wall panel having a triangular interruption space at each hinge.

22. A pre-cut and creased blank for forming a hollowwalled foldable carton as set forth in claim 19 in which the outer side wall panels each has at each hinge line at least two generally triangular web sections whose side edges radiate from the vicinity of the hinge line, near the outer edge of the panel, these sections being joined by a common fold line which lies approximately on an extension of the hinge line, and wherein also the inner side wall panels have oppositely facing generally triangular apertures having their respective apexes on the respective ridge fold lines, the bases of such triangles opposite the apexes being approximately in line with the respective hinge lines.

References Cited UNITED STATES PATENTS 2,387,790 10/ 1945 Williamson.

2,605,953 8/1952 Williamson 22934 2,713,450 7/ 1955 Williamson 229-40 2,781,898 2/ 1957 Desmond et al 229-34 X 2,914,234 11/ 1959 Aazelwood 22931 2,980,309 4/ 1961 Papas 22934 3,074,615 1/ 1963 Johnson 229-34 X 3,159,274 12/ 1964 Burt 22940 X 3,254,434 6/1966 Gintoft 229-34 X DAVIS T. MOORHEAD, Primary Examiner.

U.S. Cl. X.R. 229--34, 36

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