US 3917157 A
A tubular container having a perimeter of uniform length with a circular bottom and a square top is fitted with a cover having upwardly projecting stacking tabs suitable for maintaining a second container of the same design in a stable position atop the first container and cover.
Claims available in
Description (OCR text may contain errors)
United States Patent 1 1 [111 3,917,157 Smith Nov. 4, 1975 STACKABLE CONTAINERANDCOVER 2,298,146 10/1942 Mersbach 229/32 3,276,662 10/1966 Farquhar 229/43  lnvemor- Ernest L'smlthKansas 3,402,876 9/1968 Kuchenbecker ..229/21x 73 A i hi petroleum Company, 3,411,692 11/1968 Mathews 229/21 Bartlesvme, Okla 3,520,468 7/1970 Wiemann 206/512 x  Filed: 1974 Primary Examiner' Davis T. Moorhead  Appl. No.: 440,482
 ABSTRACT  US. Cl 229/43 R; 229/21; 206/512 51 1m. (:1. B65D 5/64; B65D 43/00 A tubular wmmer havmg a Permeter "mfmm  Field 61 Search 206/503 509 512 515 length with a Circular and a Square t0P is fitted 229 DIG with a cover having upwardly projecting stacking tabs suitable for maintaining a second container of the  References cued same design in a stable position atop the first con- UNITED STATES PATENTS tame and 2,004,818 6/1935 Luckett 229/43 x 13 Clains, 6 Drawing Figures Sheet 1 of4 3,917,157
U.S. Patent Nov. 4, 1975 US. Patent Nov. 4, 1975 Sheet 2 of4 U.S. Patent Nov. 4, 1975 Sheet 3 of4 STACKABLE CONTAINER AND COVER This invention relates to a container having a circular end and a rectangular end and a rectangular cover therefor provided with stacking tabs. In one aspect it relates to a container having a circular bottom and a reinforced square top and a cover therefor provided with stacking tabs. In yet another aspect it relates to a cover for a container having a square top.
In the production of fiberboard, paperboard, and other similar containers, particularly containers of relatively large size suitable for packaging pretzels, potato chips, and the like, it is necessary that the container have sufficient rigidity, especially when its contents are susceptible to being broken or crushed, to maintain its shape in the course of the handling, stacking, and storing associated with the distribution and sale of the packaged products. One means known in the art for imparting the desired rigidity to a container has been attaching one or both end closures of the tubular container to the container body using a rigid metal band into which the parts to be joined are clamped. This and many other methods of strengthening the paperboard containers in which the body of the container is manufactured separately from the ends of the container lend themselves to efficient use with containers having a generally circular cross section.
Tubular container bodies having a generally circular cross section can be constructed so that the diameter of the circular top is larger than the diameter of the circular bottom thereby making the containers easier to stack. The blank from which said container is formed, however, must be curved. The most efficient use of the sheet material from which the container body is made is realized when a rectangular blank is used. The use of a rectangular blank dictates that the container have generally equal top and bottom perimeters. In the case of a cylindrical container, the top and bottom will both be in the shape of circles with at least substantially the same diameter. Nearly all of the techniques for strengthening a tubular paperboard container result in a container wherein either the top or the bottom of the container, or both, are not flush with the respective top and bottom edges of the container body. In such cases stacking of the container without external support is difficult since the edge of the bottom of one container must rest on the edge of the top of the container below it.
It is an object of this invention to provide a container having improved stacking characteristics. Another object is to provide a stackable container which can be constructed with maximum utilization of the blank sheet material from which it is made. Yet another object of the invention is to provide a closure for a container having a square top. Still another object is to provide a closure for a stackable container having a round bottom and a square top. An additional object is to provide a blank from which a container having a generally round bottom and a reinforced square top can be produced. Another object is to provide a blank from which a square carton closure suitable for stackable containers can be constructed. Other objects, aspects, and advantages of the invention will be apparent from a study of the specification and the appended claims.
In accordance with the invention, a container having a tubular body formed from a rectangular blank can be reinforced at its circular bottom by any means known to the art such as bonding the bottom of the container to the tubular body by crimping a metal band around the edge of both the bottom closure member and the bottom of the tubular body. The top of the container body member is formed so that it has a square cross section capable of accepting a square closure means. The closure means can be of any basic design and has upwardly protruding tabs or other means for holding a container similar to one which it covers in a stable position above it. In one embodiment the cover is of the type which can be folded into a flat shape for storage and handling following assembly of the cover. Although the embodiment of the invention described herein is a preferred embodiment made of paperboard, variations of the material from which the container is constructed as well as variations in structural details known to persons skilled in the art are considered to be within the scope of the invention.
' IN THE DRAWING FIG. 1 is a partially exploded perspective view of a first container in a stacked position above a second container.
FIG. 2 is a partial vertical cross sectional view of a container with the closure attached.
FIG. 3 is a partial detail of the container closure of FIG. 1.
FIG. 4 is a cross sectional view taken along line 44 of FIG. 1.
FIG. 5 is a plan view of a blank from which the body of the container of FIG. 1 can be constructed.
FIG. 6 is a plan view of a blank from which the container closure of FIG. 1 can be constructed.
Referring now to FIG. 1, a container 10 having a generally tubular body member 11 and a closure 12 (shown removed from the container for the purpose of illustration) is shown in the stacked position atop a second container 10 having a tubular body member 11 and a container closure 12. Attached to the bottom container body: 11 by crimped metal ring 15 is bottom closure 13 (FIG. 2). Body member 11 is comprised of container body panels 16, 17, 18, and 19 defined by score lines 21, 22, 23, and 24. (See FIG. 5). Reinforcing flaps 26 and 27 are folded outwardly and downwardly from the topedge of container body panels 16 and 17, respectively, along score lines 31 and 32 and are adhered topanels l6 and 17 to strengthen the top of the container. Reinforcing flaps 28 and 29 (FIG. 5) are folded outwardly and downwardly from the top edge of panels 18 and 19, respectively, along score lines 33 and 34 and are adhered to panels 18 and 19. Reinforcing flaps 26, 27, 28, and 29 can be adhered to the appropriate respective body panels using conventional adhesive, hot melt adhesive, mechanical fasteners, or other'suitable means known in the art.
Closure 12 comprises central panel 35 and closure sides 36, 37, 38, and 39 (38 and 39 shown in FIG. 6). Closure sides 36, 37, 38, and 39 are joined to the central panel 35 along score lines 41, 42, 43, and 44, respectively and extend downwardly from central panel 35 at an angle of approximately from central panel 35. Stacking tab panels 46, 47, 48, and 49 partially project above the central panel 35 with the portions projecting above the central panel 35 forming stacking tabs. The use of the stacking tabs for maintaining a container in a stable position atop another containeris illustrated in FIGS. 1 and 4 by stacking tab panels 46', 47', 48, and 49 of closure 12'. In the preferred embodiment illustrated, stacking tab panels 46 and 47 are hinged to closure sides 36 and 38, respectively, along score lines 51 and 52 and are affixed to closure side 37 to maintain the closure sides perpendicular to the central panel 35. In the same manner stacking tab panels 48 and 49 are hinged to closure sides 38 and 36 along score lines 53 and 54 and are affixed to closure side 39.
FIG. 2 is a partial cross section of container 10, with closure 12 in place. Bottom closure 13 is shown attached to body panel 17 by crimped metal ring 15.
Joining the bottom closure of a container to the container body in such a manner yields a container which, although it is rigid, has a closure which is inset from the bottom edge of the container with the bottom edge of the container forming a rim around the container bottom. Because the side of the container extends below bottom closure 13, the difficulty of stacking such a container atop a container of the same circumference is readily seen. FIG. 2 also illustrates the manner in which reinforcing panel 27 is folded outwardly from and adhered to container panel 17 to reinforce the top of the container. Construction of the top of the container in this manner permits closure top 35 to rest on the fold between container panel 17 and reinforcing panel 27 with closure side 37 extending below the bottom edge of reinforcing panel 27. Closure 12 can be held in place by friction between closure sides 36, 37, 38, and 39 and reinforcing panels 26, 27, 28, and 29, by tape or adhesive, by a mechanical latching means, or by any other -means known to the art.
FIG. 3 is'a partial detail of one corner of the container closure 12. Closure sides 36 and 37 have been folded downward along score lines 41 and 42 respectively from the central panel 35 of the closure. Stacking tab panel 46 is attached to closure side 36 along score line 51. Stacking tab panel 46 is secured against closure side 37 by inserting an assembly tab of stacking tab panel 46 into slot 81 in closure side 37. Diagonal fold line 86 extends from the corner of closure side 36 nearest stacking panel 46 to a point along the bottom edge of closure side 36, and, along with a similar fold line 89 at the opposite end of panel 36 and similar fold lines 87, 88 at either end of opposite closure panel 38, per.- mits the sides of closure 12 to be folded under the closure for storage and handling prior to placement of the closure on a container 10. Fold lines 86, 87, 88, 89 can be a broken line of severance as illustrated in FIG. 3, a score line along which the closure material can be bent, or any other similar means known in the art. In addition to providing stacking tabs to aid in storing and handling packaged products, closure 12 has a central panel 35 which covers the entire top of container in a manner sufficient for the protection of packaged food products or other products where complete enclosure is important. Even though a container 10 with a cover 12 may be used in conjunction with a sealed plastic or paper bag to package products, complete and uninterrupted coverage of the top opening of the container 10 by cover 12 is important to prevent the entrance of foreign matter into the container during storage and handling of the packaged product.
FIG. 4 is a cross sectional view of the top of container cover 12 showing the circular bottom of container 10 stacked above it. The size of the cover 12' and bottom of container 10 permits all four cover corners of cover 12' to extend beyond the circular container bottom outline. Stacking tab panels 46, 47', 48', and 49' are I the containers are to be stacked, the relative strength located adjacent to the four corners of the central}, panel 35'-of cover 12. Crimped metal ring 15, con- I necting container body 11 and bottom closure 13, rests on the central panel 35' of cover 12'. If the outside diameter of the circular bottom of a container 10 is desigv nated as a distance A and the diagonal length between.
opposite corners of the central panel 35' of closure 12' is designatedas a distance 8, distance B being greater than distance A, the width of the stacking tab on stackv ing tab panels 46', 47', 48, and 49', designated by a distance C, which will be suitable for use to properly hold a container in a stacked position above closure 12 can be algebraically defined by the following formula:
The exact distance C for use with an individual container application will necessarily be determined by 7 manufacturing tolerances, the conditions under which of the material from which closure 12' is fabricated and other similar requirements or conditions applicable to each individual embodiment.
FIG. 5 is a plan view of a blank from which the body member 11 of container 10 can be constructed. Rectangular body panels 16, 17, 18, and 19, of approximately equal width, and rectangular sealing panel 71 1 are joined along scorelines 21, 22, 23, and 24. Rectangular reinforcing flaps'26, 27, 28, and 29 are joined to 6 body panels 16, 17, 18, and 19, respectively along score lines 31, 32, 33, and 34, respectively. Reinforcing flaps 26 and 27 are separated by a cut 72. Cut 72 is lo cated along the same line as score line 22. In the same manner, reinforcing flaps 27 and 28 are separated by cut 73 along the same line as score line 23 and reinforcing flaps 28 and 29 are separated by cut 74 along the. same line as score line 24. The cornerof the rectangular material from which the blank can be constructed 1 adjacent to reinforcing flap 26 and sealing panel 71 has, been removed. The finished blank therefore has a generally rectangular shape with a small rectangle of material, having a length and width equal to the width of reinforcing flap 76 and sealing panel 71 respectively, j
missing from one corner. This small rectangle of missing material is the only necessary waste material resulting from construction of the blank from properly sized l blank material stock. Although score lines 31, 32, 33, and 34 can be overlapped to form one continuous score line along the blank and score lines 21, 22, 23, and 24 can be extended to meet the bottom end of the blank and to intersect score lines 31, 32, 33, and 34, a preferred method of scoring the blank by terminating all score lines a short distance away from another score line or cut or the edge of the blank is illustrated. Scoring in this manner imparts additional strength to score line intersections with other score lines, edges of the blank, or cuts in the blank to decrease the possibility of unwanted folding or tearing during manufacture and handling of the blank without adversely affecting the ability of the blank to be readily folded into a container 1 section, while the bottom has a generally circular cross section. Sealing panel 71 and body panel l9 are overlapped and adhered to each other by any suitable means known to the art. Reinforcing flaps 26, 27, 28, and 29 are folded along score lines 31, 32, 33, and 34 outwardly and downwardly from the top edge of the container body at an angle of approximately 180 and are adhered to the outside surface of body panels 16, 17, 18, and 19, respectively, by any suitable means known to the art. The reinforcing flaps 26, 27, 28, and 29 can be folded inwardly approximately 180 and adhered to the inside surface of panels 16,17, 18, and 19 in other embodiments within the scope of the invention. A circular bottom closure can be applied to the bottom of'the tubular container body by any means known to the art to form a container 10 having a square top and a round bottom with both the top and bottom being of substantially equal perimeter;
FIG. 6 is a plan view of a blank from which container cover 12 can be constructed. The central panel 35 of the closure is defined by score lines 41, 42 43, and 44 which are of substantially equal length and are each paralleltoand located a substantially equal distance from therespective nearest edge of the generally rect: angular blank. Score lines 41 and 43 extend substan} tially the. entire length of their respective sides of central panel 35 whereas score lines 42 and 44 are terminated a distance D-away .from the corner of central panel 35 at each end of each score line. The distance D will be determinativeof the height of the stacking tab portion of stacking tab panels 46, 47, 48, and 49 and will therefore vary for different designs within the scope of the invention, depending on the materials used, the conditions of handling andstorage for which stacking stability is required,'-and other similar circumstances associated with varying applications. Score lines 51 and 52 are along the same line as score line 42 and extend from a point near one end of score lines 41 and 43 respectively to points near opposite sides of the blank. Score line 51 also defines the boundary between closure side panel 36 and stacking panel 46, and, in the same manner, score line 52 defines the boundary between closure side panel 38 and stacking tab panel 47. Score lines 53 and 54, along the same line as score line 44, extend from a point near the other ends of score lines 43 and '41 respectively to points near opposite sides of the blank. Score line 53 defines the boundary between closure side panel 38 and stacking tab panel 48, and, in the same manner, score line 54 defines the boundary between closure side panel 36 and stacking tab paanel 49. Although score lines 41, 42, 43, 44, 51, 52, 53, and 54 can extend to meet the sides of the blank, other score lines, cuts in the blanks or other similar features of the blank, a preferred method of scoring is to terminate each score line a small distance from the edge of the blank, another the score line, acut in the blank or other similar feature in order to.give additional strength to the blank and preyentinadvertent tearing or folding during handling and storage of the blank without I interfering with the assembly of.the blank into a container cover.
Stacking tab panels 46 and 47-are separated from side panel 37 by cuts 76 and 77 respectively. ln a similar manner, stacking tab panels 48 and 49 areseparated from side panel 39 by cuts 78 and 79. The shape of cuts 76, 77, 78, and 79 is selected so that stacking tab panels 46, 47, 48, and 49 will have protruding stacking tabs With the desired dimensions C and D, with C being the horizontal-length of each upwardly protruding tab and D being the height which the tab extends above the central panel 35 of the assembled cover.
Slots 81, 82, 83, and 84 are located on side panels 37 and 39 to accept assembly tabsof stacking tab panels 46, 47, 48, and 49 respectively. The assembly tabs are formed on stacking panels 46, 47, 48, and 49 by trimming the side of each panel opposite score lines 51, 52,
53, and 54 respectively to form a tab-shaped protrusion on the side of each stacking tab panel opposite its connection to the respective side panel. Although a blank is illustrated which can be assembled by inserting these tabs into their respective slots, omission of the tabs and slots from the blank will result in a blank which can be assembled into the same general container cover shape using glue, hot melt adhesive, mechanical fasteners, or other similar means to engage or attach stacking panels 46 to 47 to cover the ends of side panel 37 and stacking panels 48 and 49 to cover the ends of side panel 39. Fold lines 86, 87, 88, and 89 can be score lines, perforated lines, intermittently cut, partially cut, or other similarly weakened lines diagonally connecting a point near each end of score line 41 with a point near the outside edge of closure side 36 and a point near each end of score line 43 with a point near the outside edge of closure side 38. Thus, each end of opposite closure sides 36 and 38 has a fold line extending diagonally from a point adjacent to the respective comer of central panel 35 to a point adjacent to the side of the respective closure side opposite central panel 35. Although the angle formed by fold lines 86 and 89 .with score line 41 and by fold lines 87 and 88 with score line 43 can vary, without affecting theability of the fabricated container cover to fold flat for handling and shipment, an angle of approximately 45 is preferred because such an angle permits the assembled cover to be folded in the least possible space and exerts as little stress as possible on the means for affixing stacking panels 46 and 47 to cover side panel 37 and stacking panels 48 and 49 to cover side panel 39 while the cover is being collapsed and being stored in a collapsed condition. 1
, To assemble the blanks shown in FIG. 6 into a container cover, cover side panels 37 and 39 are folded downwardly along score lines 42 and 44 respectively from topvpanel 35 at an angle of approximately Cover side panels 36 and 38 are also foldeddownwardly fromtop-panel 35 along score lines 41 and 43 respectively at an angle of approximately 90. Stacking panels 46 and 47 are then folded along lines 51 and 52 respectively at an angle of approximately 90 overlapping cover side panel 37 and the assembly tabs on stacking panels 46 and 47 are inserted into slots 81 and 82 respectively. In a similar manner, stacking panels 48 and 49 are bent at an angle of approximately 90 along some lines 53 and 54 respectively to overlap cover side panel 39 and the assembly tabs of stacking panels 48 and 49 are inserted into slots 83 and 84 respectively. In addition to insertion of assembly tabs into slots 81, 82, 83, and'84, stacking panels 46 and 47 may be gluedor otherwise adhered to cover side panel 37 and stacking panels 48 and 49 can be adhered in a similar manner to cover side panel 39. After the container has been thus assembled, it can be flattened for storage by folding cover side panels 36 and 38 under top panel 35 and similarly folding cover side panels 37 and 39 over cover side panels 36 and 38 so that cover side panels 36, 37, 38, and 39 are all substantially folded beneath top panel 35 with folds of approximately 180 along score lines 51, 52, 53, and 54 and fold lines 86, 87, 88, and 89. When stored and shipped in this flattened position, the container cover can be easily reopened for use as a cover for the container made from the blank illustrated in FIG.. 5.
Cut lines 72, 73, and 74 of FIG. 5, as well as cuts 76,
77, 78, and 79 in slots 81, 82, 83, and 84 of FIG. 6 can be either completely severed lines or severable lines which, although they may not completely disconnect the panels which they separate, can be easily converted into completely severed lines at the time the blanks are assembled into the desired product. Some connection between adjacent panels along these cut lines can therefore remain until the container and cover are assembled in order to prevent unwanted bending or tear ing during handling or storage of the blanks without interfering with the ease of efficiency of assembly of the blanks into the desired products.
Although the invention has been described in a preferred container embodiment having a square top cross-section, the same technique can be used to construct a similar container having a container having a rectangular top with adjacent sides of different lengths, within reasonable limits, to produce a stackable container and cover therefor. While preferred methods of forming and reinforcing. the rectangular and circular ends of the container have been disclosed, any known means for forming the container ends can be used within the scope of the invention. In addition, while the preferred embodiment has a rectangular top and a round bottom, production of a container having a round top and a rectangular bottom is within the scope of the invention.
Reasonable variations and modifications are possible within the scope of the foregoing disclosure and the appended claims to the invention.
1. A container comprising a generally tubular body member having a circular end with a generally circular cross section and a rectangular end with a generally rectangular cross section, circular closure means at said circular end, and rectangular closure means at said rectangular end, said rectangular closure meanshaving an uninterrupted closure surface to provide uninterrupted coverage of the opening in said rectangular end of said container, said rectangular closure means also having a stacking tab located adjacent each of the four corners thereof with each said stacking tab projecting beyond said uninterrupted closure surface away from said circular end of said container, said circular end of said container and said rectangular closure means being sized to permit all four corners of said rectangular closure means to extend beyond the circumference of the contiguous circular end of an identical container positioned thereagainst.
2. A container in accordance with claim 1 wherein said circular closure means comprises the bottom of said container and said rectangular closure means comprises the top closure of said container.
3. A container in accordance with claim 2 wherein said rectangular end of said container comprises a square end and wherein said rectangular closure means comprises a square closure means having a square top member and four side members, depending downwardly therefrom at an angle of approximately 90 with said top member.
4. A container in accordance with claim 3 wherein the circumference of said circular end of said container and the perimeter of said square end of said container are at least substantially equal.
5. A container in accordance with claim 4 additionally comprising a reinforcing flap affixed to each wall section of said square end of said container adjacent to t the edge of said square end of said container.
6. A container in accordance with claim 5 wherein two said stacking tabs are located along each of two opposite sides of said square closure means.
7. A container in accordance with claim 6 wherein each of the two opposite sides of said square closure means along which said stacking tabs are not located has a pair of fold lines therein, each fold line being adjacent to a respective end of the side, said fold lines being positioned to permit said square closure means to be folded to a flattened shape.
8. A blank from which a rectangular container cover can be constructed comprising an uninterrupted rectangular, central surface for providing uninterrupted coverage of a rectangular opening which said cover is adapted to close; four side panels located adjacentto said central surface, each of said side panels being con-. nected to a respective side of said central surface along a score line; each of a first opposite pair of said side panels having a pair of stacking tab panels, each of said stacking tab panels being attached to a respective end of the respective side panel along a score line; said.
stacking tab panels being shaped so that when said first opposite pair of side panels are folded downward from said central surface at an angle of approximately and the remaining second opposite. pair of side panels. are folded downward from said central surface at an angle of approximately 90, each of said stacking tab panels can be folded against a respective one of said second opposite pair of side panels with a portion of each stacking tab panelextending above said central surface.
9. A blank. in accordance with claim 8 additionally comprising a pair of diagonal fold lines in each of said first opposite pair of side panels each said diagonal fold line extending from a respective end of the respective side panel at the point nearest the corner of said central 1 surface to a point along the edge of each such side panel opposite said central surface.
10. A blank in accordance with claim 9 wherein each said stacking tab panel has an assembly tab on the side I opposite its attachment to one of said first pair of opposite side panels; and wherein each side panel of said second opposite pair of side panels has a slot at each end into which the respective one of said assembly: tabs said rectangular end of ,said container comprises a square end and wherein said rectangular closure means comprises a square closure means having a square top member and four side members depending downwardly therefrom at an angle of approximately 90 with said top member.