The present invention relates to a paper or paperboard container having dove tail locks, wherein the paperboard container is created form a blank having offset, non-symmetrical dove tail locks. Further, the present invention relates to a paperboard substrate having multiple contiguous paperboard blanks, wherein the dove tail locks of one blank border the dove tail locks of an adjacent blank in a configuration that eliminates angles of less than 90 degrees.
Corrugated paperboard is typically used in many different applications, for example, to form containers, boxes, cartons, or dividers for holding, storing or shipping various items such as agricultural produce.
Typically, such containers have a bottom and four side walls, and are formed from a blank scored with score lines or cut lines. The blanks are most often formed by automated machines in a continuous in-line process involving scoring and cutting a large substrate of paperboard into blanks of a desired configuration. During scoring and cutting, multiple, virtually identical container blanks are contiguously formed on a large, single substrate of paperboard. The automated machines separate the substrate into individual blanks by severing common intermediate cut lines with cutting knives. The resultant individual blanks are then folded along the score lines or cut lines to form functional containers. The blanks may be folded into a container manually or by an automated machine.
An individual container blank, on its own, often contains knife recesses or other cut out formations along the outer edges of the blank. However, during severance from a large paperboard substrate, the outer edge of the blank borders a virtually identical blank along an intermediate common cut line. In these circumstances, the die cut recesses or other cut out formations touch each other across the intermediate common cut line, essentially forming a combined cut out shape. For example, a blank may include dove tail locks, which are recesses having a flat base and two angled side walls that extend from the base to an open mouth top at the edge of the side wall, and may further have identical recesses on an opposing side edge. When this happens on contiguous blanks on a larger paperboard substrate, the open mouth of the dove tail lock on one blank will border the open mouth of a dovetail lock on an adjacent blank. As a result, the two bordering locks form a single, larger cut out shape that traverses the intermediate common cut line. When the blanks are fully separated across the intermediate common cut line, the individual blanks once again have separate dove tail locks.
However, to account for the thickness of the blank's panels when they are folded over one another during the formation of the container, the recesses cut out of one end of a blank are sometimes offset from the recesses on the opposite end of the blank by moving one recess a small lateral distance as opposed to the other. For example, the dove tail lock on one end of a blank can be laterally spaced ⅛ inch from a dove tail lock on the opposing edge. Stemming from that offset, when the blanks are arranged adjacently on a single substrate, the dove tail locks on one blank are offset from the bordering dove tail lock on the adjacent blank. That is to say, the open mouth top of the dove tail lock on one blank does not perfectly align with the open mouth top of the adjacent dove tail lock. This results in a combined cut out shape having sharp angles of less than 90°, called pinch points, which are undesirable because they are difficult to properly cut, leaving frayed edges and causing extra wear and tear on the cutting knife.
Therefore, it is an object of this invention to provide a paperboard blank that eliminates pinch points when aligned with an adjacent, identical blank on the same paperboard substrate.
The present invention comprises a paperboard container formed from a paperboard blank, wherein the blank contains non-symmetrical offset dove tail locks, which eliminate pinch points and increase the ease of separating the blank from a larger paperboard substrate.
The container is a corrugated box of a type often used for transporting food items, with a bottom side, two side walls, two end walls and a removable lid. The container further contains dove tail locks on the end walls to facilitate the locking of the container in an upright, erect position. A dove tail lock, as stated above, is a cut recess wherein the shape of the recess resembles a tail of a bird, that is to say, it is a recess with a base line, two angled slope lines moving in diverging or converging paths, and an open mouth top.
When the container is in its blank form, the dove tail locks are cut into opposing sides of the container blank. Each dove tail lock is offset from its opposing dove tail lock by a small lateral distance to account for the thickness of the paperboard during folding. However, the offset opposing dove tail locks are non-symmetrical, such that each slope line of the dove tail locks extend at different horizontal distances (vectors). The different vectors result in each slope line extending a different horizontal distance during its path from the base line to the open top than its corresponding, opposing slope line. The difference in the horizontal distances eliminates pinch points by aligning the open mouth tops of two adjacent dove tail locks together.
One embodiment of the invention includes dove tail locks having a base line, two slope lines and an open mouth top, wherein the slope lines of the locks are single lines that angle divergently away from each other at different angles relative to the base line. Each slope line of the dove tail locks crosses different horizontal vectors, creating a non-symmetrical lock that eliminates pinch points when multiple blanks are contiguously scored and cut on a single paperboard substrate.
Further embodiments include dove tail locks wherein the slope lines of the locks are segmented. In these embodiments, one segment extends perpendicular to the base and in parallel to a corresponding segment on the opposing side of the lock. The parallel segments combine with second segments that extend divergently away from each other at different angles relative to the base line and the first segments. This embodiment also results in each slope line of the dove tail lock traveling different horizontal vectors, eliminating pinch points when the blank borders an adjacent blank on a paperboard substrate.
Other objects, embodiments, features and advantages of the present invention will be apparent when the description of a preferred embodiment of the invention is considered in conjunction with the annexed drawings, which should be construed in an illustrative and not limiting sense.
a–7b are perspective views of the container blanks of
Each end flap has at least one dove tail lock 2. The dove tail locks are die cut recesses, cut from the outer edge of the side panels. Referring to
To erect the container, side panels 20 and 40 of
To overlap properly, however, the thickness of the paperboard must be accounted for. Failing to do so would result in end panel 22 and end panel 26 obstructing each other by attempting to fold into the same location. Avoiding this requires the length of end panel 22 to be slightly different than the length of end panel 26. As a result of this length difference, each end panel naturally folds next each other without interference.
Corresponding with the length differences of the end panels, the dove tail locks on end panels 22 are offset a small lateral distance as compared to the dove tail locks on end panels 26. This offset accounts for the thickness of the paperboard and allows the dove tail locks to properly align with each other when overlapped on the end wall.
Prior art blank 10 is generally scored and cut on a large paperboard substrate with multiple other blanks in a continuous in-line process.
One embodiment of the present invention is shown in
Each side flap has at least one dove tail lock 2. The dove tail locks are die cut recesses, cut out from the outer edge of the side panels. The die cut recesses are generally trapezoidal in shape, with a base line 34, two opposing slope lines 42 and 44 diagonally diverging at different angles relative to the base line, and an open mouth top. The different angles of the opposing slope lines result in different horizontal vectors of the slope lines, i.e., the slope lines travel different horizontal distances as they extend from the base line to the open top mouth. For example, in the present example, slope line 42 has a horizontal vector of ¼ inch, while slope line 44 has a horizontal vector of ⅛ inch. In general, the difference of the horizontal vectors of the two slope lines is equivalent to the difference in length of end flap 22 and end flap 26.
In the embodiment shown in
To erect the container of
Third, end panels 24 are folded about horizontal axis 32 upwards 90° out of the plane. The end flaps 22 and 26 overlap each other and end panel 24 in a face-to-face-to-face arrangement, resulting in a three-ply end wall that is triple the thickness of the blank. The locking flap 60 is then pulled down through the dove tail locks of flaps 22 and 26, locking the container in an erect position, shown in
An alternate embodiment is shown in
When blank 10′ of
As noted previously, the slightly different lengths of the end flaps 22 and 26 compensate for the thickness of the material of the blank. See
In alternate embodiments, slope lines 42 and 44 may have different geometric arrangements, for example, containing only an angled segment without a first segment that extends perpendicular to the base line. However, in these embodiments, the integrity of the horizontal vector of sides 42 and 44 is maintained. That is to say, side 42 would still have the same horizontal vector Y, whereas slope line 44 would have a horizontal vector X, different from that of Y, resulting in the elimination of corners with angles of less than 90° when adjacent container blanks touch on a larger paperboard substrate.
Although the invention has been described with reference to preferred embodiments, it will be appreciated by one of ordinary skill in the art that numerous modifications are possible in light of the above disclosure. For example, the base line of the dove tail locks may be cut non-parallel to the edge of the blank or intermediate cut line. Further, the slope lines of the dove tail locks may be further segmented. All such variations and modifications are intended to be within the scope and spirit of the invention as defined in the claims appended hereto.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/365,007, filed Mar. 14, 2002.
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Number | Date | Country | |
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20040007613 A1 | Jan 2004 | US |
Number | Date | Country | |
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60365007 | Mar 2002 | US |