US2987237A

US2987237A - Folding box having diagonally overlapping closing panels

Info

Publication number: US2987237A
Application number: US750249A
Authority: US
Inventors: Robert P Bemiss; Jack G Herring; Richard C Stenger
Original assignee: BINNS MACHINE WORKS Inc
Current assignee: BINNS MACHINE WORKS Inc
Priority date: 1958-07-22
Filing date: 1958-07-22
Publication date: 1961-06-06
Anticipated expiration: 1978-06-06

Description

June 6, 1961 R. P. BEMls Erm. 2,987,237

FOLDING BOX HAVING DIAGONALLY OVERLAPPING CLOSING PANELS Filed July 22, 1958 4 Sheets-Sheet 2 ROBERT- mss/mss JACK G. Hsefzw@ RICHAR@ C. STENG ER INVENTORS #q1-um s W mi ATTORNEY June 6, 1961 R. PL BEMlss Erm. 2,987,237

FOLDING Box HAVING DIAGQNALLY OVRLAPPING CLOSING PANELs 4 Sheets-Sheet 3 Filed July 22, 1958 www mAc. ma Rey l E m G. w ATTORNEY Julie 6, 1961 R. P. -BEMlss ErAx. 2,987,237

i FOLDING Box HAVING DIAGONALLY OVERLAPPING CLOSING PANELs Filed July 22, 1958 4 Sheets-Sheet 4 reos Ere?- f?. BEM/ss Amc cs. HERR/NQ le :cf-f A@ c. STE/v6 E@ JNVENToRs .mug ATTORNEY United States Patent O 2,987,237 FOLDING BOX HAVING DIAGONALLY OVER- LAPPING CLOSING PANELS Robert P. Bemiss, Burlingame, Calif., Jack G. Herring, f Portland, Oreg., and Richard C. Stenger, San Carlos,

Calif., assignors to Binns Machine Works, Inc., Redwood City, Calif., a corporation of California Filed July 22, 1958, Ser. No. 750,249

7 Claims. (Cl. 229-40) This invention provides au improved self-locking folding box having four diagonally overlapping closing panels, and further provides a method of setting up the box blank.

Gluelessly assembled folding boxes having four diagonally overlapping closing panels are known in principle. The basic blank for a box of this style comprises a centrally located bottom panel to which side wall panels are articulated-along the four sides. YTop panels extend om the side wall panels. The top panels are roughly of triangular shape and overlap along marginal areas disposed substantially diagonally with respect Vto the square or rectangular top surface of the box.

A principalY feature of this sryie of box is that it re;

quires a minimum of stock, since the box is practicallyV ofY single ply thickness throughout, except at the areas of overlap.

A principal diculty encountered with forms of known boxes of the aforementioned style is the limited resistance of the box to twisting. Lack of resistance to twisting not only limits Ithe strength of the box, but it may also lead tol a failure of the box closure, since in a twisted box the margin of overlap of the top panels is easily reduced to a point where the four top panels separate. This difficulty may be met to some extent by making the areas of overlap wider, but such a change sacrifices the principal advantage of this style of box which is the small amount of board theoretically required.

Certain knownforrns of boxes employ interlocks in which opposite triangular Vtop panels are locked together at their peak. This form of interlock is unsatisfactory because it affords no resistance to twisting since opposite locked panels are free to slide'substantially parallel to each other. A box of square top outline is therefore readily twisted into the shape of a rhombus, and a rectangular box into the shape of a rhomboid.

One known form of box employs an interlock between opposite-panels in which the apex of one of the top panels is shaped substantially in the form of an arrowhead and inserted into a slit in the opposite top panel. 'I'he resulting'engagement leaves the two panels free to slide parallel to one another and provides little, if any, resistance to twisting.

The invention provides an improved form of box and blank in which one of the top panels is interlocked with the two adjoining top panels by a centrally disposed lock which alfords a surprisingly high degree of twist resistance and permits the amount of overlap between the panels to be held extremely small. The invention further provides a method of assembling at blanksV into box form and locking three' of the top panels in such a manner that the 'interlock is relatively loose and easy to engage during the initial phases of the locking operation, but isautomatically tightened when the three top panels are brought into their nal position in which the box is also fully squared.

The various features and advantages ofthis invention will appear more fully from the detailed description which follows accompanied by drawings showing, for the purpose of illustration, a preferred embodiment of the invention. The invention also resides in certain new and original features of construction and the combination of y by-two main locking cuts 47 and 48 extending from the- Patented June 6,y 1961 FIG. 2 is a perspective view of a box in -a condltionr immediately prior to closing;

FIG. 3 is a perspective view of a device for setting up and locking three top panels of the box automatically;

FIG. 4 is a perspective view of the device of FIG. 3 showing a partially folded blank engaged by a mandrel; and

FIGS. 5 through 8 illustrate successive phases in the folding and locking operations resulting in a box structure ready for filling with merchandise and subsequent closing. In the following description and in the claims various details will be identified by specific names for convenience. Ihe names, however,.are intended to be generic in their application. Corresponding reference characters refer -to corresponding parts in the several figures of the drawings.

The drawings accompanying, and forming part of, this specification disclose certain specific details of the invention for the purpose of explanation of its broader aspects, but it is understood that the details may be modified in various respects without departure from the principles of the invention and that the invention may be applied to` other structures than the one shown.

The blank A shown in FIG. l may be cut and scored, in multiple, from large sheets or rolls of foldable board, for example paperboard, on automatic cutting and creasing machines. The blank may be of waxed board which, as is well known, does not lend itself to convenient gluing. The invention permits the blank to be formed into box shape entirely by folding and glueless interlocking.

The blank comprises a bottom panel l11 to which

side wall panels

12 and 13 are articulated along bottom side fold lines 14 and 15. Lateral

top panels

16 and 17 are articulatedto the

side wall panels

12 and 13 along top

side fold lines

18 and 19.

A back panel 20 is articulated to the bottom panel 11 along a bottom back fold line 21, and a main top panel 22 is articulated to the back panel along a top back fold line 23. On the opposite side of the blank a front panel 24 is articulated to the bottom panel 11 along a bottom front fold line 25, and a front top panel 26 is articulated to the front panel along a top front fold line 27.

`V The blank areas between the side wall panels and the back and front panel, respectively, may be used as corner gussetsin a conventional manner, but are shown in the illustrated form of blank as

corner aps

28, 29, 30 and'. 31, articulated to the side wall panels along

Hap fold lines

32, 33, 34 and 35, respectively.

The

lateral top panels

16 and 17 are of substantially triangular shape and are preferably truncated at the tops at 36 and 37 to facilitate assembly. Locking cuts 38 and 39 extend into the lateral panels from the side edgesin a direction toward the truncated apex and form

side locking tabs

40 and 41 pointing away from the respective sides of the main panel into the board in a direction away from the arrowhead, thereby forming

main locking tabs

49 and 50 to either side of the neck. The tabs 49 and 5l)Y point towardsr the arrow point 43.

The base portion S1 of the main panel which lies adjacent the top back fold line 23 is substantially rectangular and is characterized by opposite

parallel side edges

52 and 53. Similarly, the front top panel 26 has a base portion 54 characterized by parallel side edges 55` and 56. The parallel side edges serve to tighten the central interlock of the lateral top panels with the main top panel, as will later appear.

The blank A may be shaped into hollow box form either by hand or, more economically, by an automatic forming and locking device in a manner about to be described. Y

'Ihe assembly device shown in FIG. 3 comprises a mandrel 57 movable between

rails

58 and 59. The mandrel is of square bottom outline, the bottom area being just slightly smaller than the area of the bottom panel 11 of the blank. The side surfaces of the mandrel are substantially perpendicular at the front and back, but are upwardly and inwardly slanted at the sides, as shown particularly Well in FIG. 5 at 60 and 61, to permit the side wall panels of the box blank to be folded into a position beyond the vertical for reasons which will hereinafter appear. As a result of the slant of the sides 60 and 61 the

lateral top edges

62 and 63 converge rearwardly.

The mandrel is tted with a resilient front bumper- 64 which may be depressed against the action of springs 65 to lie llush with the front surface 66 of the mandrel. As particularly well visible in FIG. 4, the mandrel has a recess 67 into which the bumper 64 may be depressed.

The top surface 68 of the mandrel has a leading depressed portion 69 so as to permit the main top panel of the blank to be depressed into a position slightly below the remainder of the top surface of the plunger.

The mandrel is moved between the

rails

58 and 59 by a reciprocable rod 70. During its forward stroke the mandrel 57 first encounters a plow or sweep 71 for engaging and folding a blank advanced by the mandrel and moves thereafter into the space between lateral resilient

folding elements

72 and 73 adapted to fold the side walls of the blank beyond the 90 degree position with respect to the bottom panel againstithe side surfaces 60 and 61 of the mandrel. Further folding and locking elements will be described in connection with the following explanation of the assembly procedure. Y

At the start of the operation shown in FIG. 4 the blank A is placed underneath the mandrel 57 with the result that the lateral rails 58 and 59 maintain the side wall panel and the lateral

top panels

16 and 17 substantially vertical. The

corner aps

28 and 30 are folded sub.- stantially at right angles with respect to the side wall panels in which position they clear the front bumper 64. The main top panel 22 extends upwardly and is about to be folded down by the plow '7.1 as the mandrelV 57 advances. During the assembly operation the blank moveS with the back panel 20 leading and the front top panel 26 trailing.

FIG. 5 shows the mandrel 57 in an advanced positionY in which the main top panel 22 is folded over the de pressed top portion 69 of the mandrel. The bumper 64 is still fully extended at this phase of the operation and engages the blank near the toprback fold line 23 along which the main top panel is articulated to the back panel 20.

The lateral

top panels

16 and 17 are about to be engaged by the ploW 71 which then folds the lateral top panels into a position in which their'truncated apexes overlap, as shown in FIG. 6.

Y Shortly after theleading portion ofV theblank passes the plow 71, the lateral folding elements 72 and Y73 engage` naamw r the side wall panels of the blank and urge them against the inwardly sloping side surfaces of the mandrel 57 so that the overlap of the apexes of the lateral top panels becomes greater than it is in the nally assembled box. In this position the ends of the side locking tabs 40 and r41 are spaced less than the ends ofthe

main locking tabs

49 and 50.

At this phase of the operation, the back panel 20' of the box which is engaged by the bumper 64 is still forwardly slanted. As a result, the arrowhead 42 is in advance of the side locking tabs 40 and 41.y During the next phase of the assembly operationthe main top panel 22 is engaged by a nger 74 which depresses the main top panel into the depressed portion 69 of the mandrel into a position slightly below the plane of the

lateral topi panels

16 and 17 so that it will pass underneath the lateral'top panels.

In the position shown in FIG. 7 the extended front bumper of the mandrel (not visible in the figure) maintains the back panel 20 of the box at a forward and upward slant until the back panel engages a transverse bar 75. This happens shortly after the point 23 of the arrowhead clears the end of a downwardly extending blade 76` mounted on a transverse bracket 77. VAs the mandrel 57 advances from the position shown in FIG. 7V to a position shown in FIG. 8, the back panel 20'of the box is erected by the transverse bar 75. 'Ihe bumper is depressed into the recess 67 and the arrowhead 42 moves in a reverse di-Y- rection with respect to the mandrel 57. This causes the arrowhead toL ride up on the blade 76 while the remainder of the panel 22 including the side locking tabs 40 and 41y (only tab 40V is visible in FIG. 7) slide underneath the lateral

top panels

16, 17. This motion causes the

main locking tabs

49 and 50 to engage the

side locking tabs

40 and 41.

Shortly after the initial locking engagement takes place,

the parallel side edges 52 and 53 of the, maintop panel,

enter between the side wall panels ofthe box, thereby forcing the side wall panels as well as the lateral top panels 1-6` and 17' apart into a position in which the ends of the

side locking tabs

40 and 41 are spaced farther apart than the ends of the

main locking tabs

49 and 50. The

spacing of the

main locking tabs

49 and 50 may also beY vice. A V-shaped cutout 78 (FIG. 4) provides clearance for the trailing front top panel 26 which is stilly at and extended andY lies in substantially the same plane as theY bottom panel 11. Y

After lling ofthe box with merchandise, the front panel 24 and the front top panel 26 are folded into closing position and the front top panel 26 lis inserted underneath the lateral

top panels

16 and 17. V'I'he parallel side edges S5 and 56 of `the front top panel urge the

side wall panels

12 and 13 apart, thereby further tightening the central lock of the top panel assembly byrpulling the

side locking tabs

40 and 41 apart.

The locked box is surprisingly strong and rigid, and is particularly twist resistant. YThe diagonally disposed areas of overlap may be quite narrow, thereby resulting in great economy of board. lFor example, an overlap of onequarter of an inch is found sucient in a box having a bottom panel measuring 5 x 5 inches.

What is claimed is:

1. A folding box comprising, a bottom panel; two side wall panels articulated to said bottom panel along bottom side fold lines; a front panel and aback panel articulated to said bottom panel along a bottom front fold line and a bottom back fold line, respectively, extending at right angles to the side fold lines; and four top panels including two lateral top panels articulated to said side wall panels along top side fold lines, a front panel articulated to said front wall panel along a top front fold line, and a main top panel articulated to said back panel along a top back fold line, said top panels being of substantially triangular shape, the sides of the triangles overlapping along marginal edge portions, the overlapping portions extending substantially diagonally of the top structure, the main panel having an apex portion substantially of arrowhead shape, the arrowhead having a point, wings in back of the point, and a reduced neck in back of the Wings, the neck being formed by main locking cuts extending from the sides of the main panel into the stock in a direction away from the arrowhead forming main locking tabs to either side of the neck, said tabs pointing towards the arrow point, each of the lateral panels having side locking cuts extending from a side edge into the panel in a direction towards the apex of the lateral panels forming a side locking tab pointing away from the apex, the inner portions of the locking tabs being engaged in the locked box in a position in which the side locking tabs underlie the main panel and the main locking tabs underlie the side panels, the arrowhead overlying the center of the top structure.

2. A folding box comprising a substantially square bottom panel; two side wall panels articulated to said bottom panel along bot-tom side fold lines; a front wall panel and a back wall panel articulated to said bottom panel along a bottom front fold line and a bottom back fold line, respectively; and four substantially triangular top panels including two lateral top panels articulated to said side wall panels along top side fold lines, a top front panel articulated to said front wall panel along a top front fold line, and a main top panel articulated to said back wall panel along a top back fold line, said top panels having overlapping marginal edge portions which extend substantially diagonally of the box top structure, the two lateral panels being truncated at their apexes suiliciently to prevent overlap at the center of the box top structure when the lateral panels are in closing position, the main panel having an apex portion substantially of arrowhead shape, the arrowhead having a point, wings in back of the point, and a reduced neck in back of the wings, the neck being formed by cuts extending from the sides of the main panel into the stock in a direction away from the arrowhead and substantially parallel to the sides of the triangle, thereby forming main locking tabs to either side of the neck, said tabs pointing towards the arrow point, said main panel comprising a substantially parallel sided base portion adjacent the top back fold line above which base portion the triangular portion of the panel rises, the lateral panels having locking cuts extending from their side edges into the panels in a direction towards the truncated apex of the lateral panels, said locking cuts forming side locking tabs adapted to be engaged in a hook type engagement with the main locking tabs in a position in which the side locking tabs underlie the main panel, the main locking tabs underlie the side panels, and the arrowhead overlies the center of the top structure, and in which the said base portion urges the side wall panels spaced by engagement at the' top side fold lines in a position in which the tips of the side locking tabs are spaced farther apart than the tips of the main locking tabs.

3. A folding box comprising, a bottom panel; two side wall panels articulated to said bottom panel along bottom side fold lines; a front panel and a back panel articulated to said bottom panel along a bottom front fold line and a bottom back fold line, respectively, extending at right angles to the side fold lines; and four top panels including two lateral top panels articulated to` said side wall panels along top side fold lines, a front top panel articulated to said front wall panel along a top front fold line, and a main top panel articulated to said back panel along a top back fold line, said top panels being of substantially triangular shape, the sides of the triangles overlapping along marginal portions, the overlapping portions extending substantially diagonally of the top structure of the closed box, the main panel having an apex portion substantially of arrowhead shape, the arrowhead having a point, wings in back of the point, and a reduced neck in back of the wings, the neck being formed by main cuts extending from the sides of the main panel into the stock in a direction away from the arrowhead forming main locking tabs to either side of the neck, said tabs pointing towards the arrow point, the lateral panels having locking cuts extending from their side edges into the panels in a direction towards the apex of the lateral panels forming side locking tabs pointing away from the respective apex, the locking cuts being so located with respect to the main cuts that an internal portion of each main cut coincides with a portion of a locking cut in a lateral panel, when the panels are in marginally, overlapping box closing position for interengagement of the main locking tabs with said side locking ta-bs in hook-type engagement.

4. A folding box comprising, a bottom panel; two side wall panels articulated to said bottom panel along bottom side fold lines; a front panel and a back panel articulated to said bottom panel along a bottom front fold line and a bottom back fold line, respectively, extending at right angles to the side fold lines; and four top panels including two lateral top panels articulated to said side wall panels along top side fold lines, a front top panel articulated to said front wall panel along a top front fold line, and a main top panel articulated to said back panel along a top back fold line, said top panels being of substantially triangular shape, the sides of the triangles overlapping along marginal portions, the overlapping portions extending substantially diagonally of the top structure of the closed box, the main panel having an apex portion substantially of arrowhead shape, the arrowhead having a point, wings in back of the point, and a reduced neck in back of the wings, the neck being formed by main cuts extending from the sides of the main panel into the stock in a direction away from the arrowhead forming main locking tabs to either side of the neck, said tabs pointing towards the arrow point, the lateral panels having locking cuts extending from their side edges into the panels in a direction towards the apex of the lateral panels forming side locking tabs pointing away from the respective apex, the locking outs being so located with respect to the main cuts that an internal portion of each main cut in the main top panel coincides with a portion of a side locking cut in a lateral panel when the panels are in marginally overlapping, box closing position, the tips of the side locking tabs being spaced farther apart than the tips of the main locking tabs.

5. A folding box as set vforth in claim 4 in which the lateral panels are truncated suiiciently so as not to overlap in the position in which the main panel and the lateral panels are in box closing position in which also the main locking tabs underlie the lateral panel and the side locking tabs underlie the main panel in locking interengagement of the main panel with the lateral panel.

6. A folding box as set forth in claim 4 in which the main top panel comprises a substantially parallel-sided rectangular base portion adjacent the top back fold line above which base portion the triangular portion of the main panel rises, the distance between the parallel sides of the base portions being substantially equal to the distance between the bottom side fold lines.

7. A folding box as set forth in claim 4 in which both the main top panel and the front top panel comprise a References Cited in the le of this patent UNITED STATES PATENTS Arneson ..f- D ec. 4,' 1956 Bolding Mar. 5, 1,957 Sparks May 1431957 Klein Feb. 25, 1958