AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant/s: Warren Brent Davis Actual Inventorls: Warren Brent Davis Address for Service is: SHELSTON IP 60 Margaret Street Telephone No: (02) 9777 1111 SYDNEY NSW 2000 Facsimile No- (02) 9241 4666 CCN: 3710000352 Attorney Code: SW Invention Title: IMPROVED REUSABLE NESTING AND DENESTING PLASTIC CONTAINER The following statement is a full description of this invention, including the best method of performing it known to me/us: File: 53022AUP00 5010723ED1.000644 -2 IMPROVED REUSABLE NESTING AND DENESTING PLASTIC CONTAINER FIELD OF THE INVENTION The present invention relates to blow molded plastic containers in which food 5 or food-related products, including cheese, may be stored. BACKGROUND OF THE INVENTION Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of 10 common general knowledge in the field. The food industry initially utilized containers made from steel for holding and/or transporting food, especially for holding and/or transporting cheese. Increased weight, cost, the undesirable appearance of rust and other considerations have led many food manufacturers and transporters of food to switch from steel to plastic containers. IS Small plastic containers are typically injection molded, allowing for greater flexibility in the design and manufacture of the shapes and contours of the containers. Larger, industrial sized containers, on the other hand, are typically blow molded, which encumbers design flexibility. For example, sharp corners and other design features may be designed and manufactured via injection molding with relatively few complications 20 by, for example, the use of mold slides and other injection molding tools. The same design features, however, present greater challenges when manufacturing a larger, industrial sized container by blow molding. Thus, many features that would appear straightforward to use in smaller containers are often times deemed not feasible or altogether avoided in the manufacture of larger containers. 25 The containers must, nonetheless, meet several design criteria while still being hampered by blow molding manufacturing limitations. For example, the containers must be sufficiently durable to withstand forces during transport, such as the pressure from the food or food-related products pushing against the container walls and/or external forces from the containers bouncing or being pushed against a side of a 30 transport vehicle. The containers must also properly store the food and still be sufficiently light for ease of handling. To be easily stored, lids are removed from the containers, and the containers are nested within one another. But, the internal pressure from the food pushing outward -3 against the container often causes the lower container portions and container bottoms to protrude outward and to permanently deform. The deformation makes it difficult and, in some cases, impossible to nest the containers within one another, Further, the containers must not buckle when subject to compressive forces. SIn an attempt to prevent the lower container portions from deforming outwardly, some manufacturers implemented partial external ribbing that covered only about one-quarter of the lower container portion. The partial ribbing showed marginal, if any, benefits to prevent deformation - but the buckling problem and container floor deformation problems persisted. 1o In addition, because the containers are typically very heavy, especially when containing the food product, individuals typically tilt and roll the containers on a bottom annular leg of the container. The annular leg used on many containers, however, is relatively feeble, having about the same thickness as the container wall. Because of the large forces borne by the legs, the legs often permanently deform and, in extreme cases, 15 fracture. Some steel containers incorporate stacking beads to prevent a top container from sliding all the way within a bottom container in which the top container is nested. The stacking beads, however, are subject to large shear forces from the bottom containers pushing up on the stacking beads of the top containers. Specifically, the shear 20 forces may cause the bead to bend upward or, in extreme cases, fracture. Further, when containers in the art are nested within one another, they often become wedged, making it difficult to denest (separate the containers from one another) the containers. Containers known in the art are also subject to other manufacturing and use problems. Accordingly, there exists a need for an improved plastic, blow molded 25 container that addresses the shortcomings of the containers now used in the art. It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 30 The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein: -4 FIG. 1 is a front view of a first container incorporating embodiments of the invention; FIG. 2 is a cross-sectional view along the line A-A shown in FIGS. I & 9; FIG. 3 is a cross-sectional view along the line 13-13 shown in FIG. 1; s FIG. 4 is a blown up and cross-sectional view of the area shown by the letter X in FIG. 1, FIG. 5 is a blown up and cross-sectional view of the area shown by the letter Y in FIG. 1; FIG. 6 shows a plurality of containers stacked atop of one another pursuant to Io embodiments of the invention; FIG. 7 shows a bottom view of a container bottom pursuant to a fourth embodiment of the invention; FIG. 8 is a more detailed front view of the first container incorporating embodiments of the invention. 15 FIG. 9 is a front view of a second container incorporating embodiments of the invention; FIG. 10 is a cross-sectional view along the line B-B shown in FIG. 9; FIG. 11 is a blown up and cross-sectional view of the area shown by the letter X in FIG. 9; and, 20 FIG. 12 is a blown up and cross-sectional view of the area shown by the letter Y in FIG. 9. DETAILED DESCRIPTION OF THE INVENTION While the present invention is susceptible of embodiment in various forms, 25 there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated. It should be further understood that the title of this section of this 30 specification, namely, "Detailed Description Of The Invention", relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.
-5 In the present disclosure, the words "a" or "an" are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular. Unless the context clearly requires otherwise, throughout the description and 5 the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". The present invention pertains to a blow molded plastic container configured to hold food or food-related products, including cheese. Pursuant to an embodiment of 10 the invention, the container includes extended vertical ribs that have a height that spans at least about ninety-five percent of a height of a lower portion of the container. It is believed that the extended ribs prevent buckling of the container, Pursuant to another embodiment of the invention, the container includes a reinforced annular leg that is at least greater than the thickness of the container wall. It is 15 believed that the reinforced leg better absorbs forces when the container is tilted and rolled along the leg. Pursuant to further embodiment of the invention, the stacking bead is positioned between the lower and upper container walls, and the lower container wall is inwardly offset from the upper container wall. It is believed that such a configuration 20 reduces the shear stress that the stacking bead is subjected to and, thus, reduces potential deformation and failure of the stacking bead. Pursuant to yet another embodiment of the invention, the container bottom is reinforced with continuous ribbing as opposed to only partial ribbing incorporated in containers known in the art. It is believed that the continuous ribbing increases strength 25 and reduces container bottom deformation. Pursuant to still another embodiment of the invention, the plane of the bottom wall is positioned such that when the toe of the container is placed flat on a floor, the container bottom is spaced from the floor when the container is empty, and does not protrude beyond the bottom of the toe when the container is full. 30 Pursuant to a sixth embodiment of the invention, an area just beneath the stacking ring can have an additional chamfer to permit adaptation to particular configurations of fork lifting equipment or to permit air flow so as to negate the potential for vapor lock holding stacked containers together.
-6 Pursuant to a seventh embodiment of the invention, ribs can extend all the way up to the stacking ring to permit air to flow during nesting and denesting the containers to facilitate air to flow and prevent the formation of too much pressure in the stacked containers that can inhibit stacking, or prevent the formation of too little 5 pressure in the nested containers that may inhibit denesting. In one embodiment of the invention shown in FIG. 1, the container 10 includes lower and upper container portions 12, 14 that are separated by a stacking bead 16. The lower and upper portions 12, 14 are formed from lower and upper container walls 18, 20, respectively. The upper portion 14 includes a rim 22 that defines a t container opening 24 and that has a diameter DR, which is about twenty-four inches in a preferred embodiment. The rim 22 preferably extends outward from the container upper portion 14 to facilitate nesting. Specifically, the outward extension 26 of the rim 22 pushes up against a bottom surface 28 of the stacking bead 16 of a top container 30 (FIGS. 5 & 6) under which a lower container 32 is positioned. In a preferred is embodiment, the stacking bead 16 has a diameter Ds of about twenty-four inches, and the upper portion 14 depends straight downward so that the diameter just below the rim 22 is substantially the same as the diameter just above the stacking bead 16. To further facilitate nesting, the lower portion 12 of the container 10 tapers inward so that a diameter of the container bottom Dca has a diameter smaller than the 20 diameter of the upper portion and, in a preferred embodiment, a diameter of about twenty inches. The container 10 shown ir FIG. l is comprised of a plastic material and, in a preferred embodiment: the container is comprised of high density polyethylene; the height of the container Hc is about thirty-six inches; the height of the lower portion HLP 25 is about twenty-five inches; the thickness of the rim Ta is between about one-quarter and three-eighths of an inch; and, the thickness of the stacking bead Tse is between about one-eighth and one-quarter of an inch. Pursuant to the first embodiment of the invention shown in FIGS. 1, 2 and 3, extended vertical ribs 36 have a height that is at least about ninety-five percent of the 30 height of the lower container portion HLp. The ribs 36 are defined by substantially smooth curves and can be defined by, for example, oval type shapes, In an alternative embodiment of the invention shown in FIG. 9, the container has one or more air passage vertical ribs 37 that extend all the way up to the bottom surface 28 of the stacking bead -7 16. In a further alternative embodiment, the extended ribs 36 are defined by substantially semi-circular cross sections. It is believed that, when known containers are subject to forces, portions of the lower container "panel" and transform from being substantially circular to becoming 5 substantially oval and form flat areas. it is believed that the flat areas lead to unwanted buckling when the containers are subject to compressive forces. The extended vertical ribbing 36 of the first embodiment is believed to prevent paneling and, thus, buckling. Further, it is believed that the ribs 36 allow for increased air flow paths when containers 10 are denested (separated from one another when nested within one another), thus 10 easing the denesting process. The depth of the ribs DvR, e.g., the amount the ribs extend into the interior of the container 10, should not be too large in order to avoid problems cleaning the container 10 after food product is removed from the container. Further, there should be a sufficient number of ribs 36 to prevent paneling, and the ribs should be spaced from one 15 another. In the first embodiment, the extended vertical ribs 36 are defined by a radius RVR that is about equal to how far the ribs are spaced S from one another, and the depth of the ribs DVR is about one-quarter of the spacing S distance, In the preferred embodiment, the ribs are defined by a radius of about 0.63 inches. Pursuant to the embodiment of the invention shown in FIGS. 1 and 4, a 20 reinforced annular leg 38 is formed along the container bottom 34. The reinforced leg 38 includes a thickness that is greater than the thickness of the container wall TCw. which is about 0.19 to about 0.25 inches thick in a preferred embodiment. In the first embodiment, the reinforced leg is defined by first and second thicknesses TaLl, TRU, both of which are greater than the thickness of the container wall. In one preferred 25 embodiment, the first thickness TRLI is about two times as thick as the container wall 18, 20 and is about 0.38 to about 0.5 inches thick; and, the second thickness TRU is about two and one-quarter times as thick as the container wall 18, 20 and is about 0.43 inches to about 0.56 inches thick. Further, in the embodiment of FIGS. I and 4, there is a gap 40 between the 30 reinforced leg 38 and other portions of the container bottom 34. The gap is defined by a width To that is not more than about five times as wide as the container wall thickness Tcw and, in a preferred embodiment, is about 0.75 inches wide. The height of the gap Ha -8 is not more than about five times as thick as the container wall thickness Tcw and, in a preferred embodiment, is about 0.75 inches high. The increased thickness and material of the reinforced leg 38 allow the reinforced leg to better withstand forces that it is subjected to when the container 10 is 5 tipped on its side or rolled, when the entire weight of the container is borne by the leg. Those of skill in the art will appreciate that, although a particular shape and design of a reinforced annular leg 38 is shown, many other reinforced annular legs are covered by the scope of this invention that have a thickness greater than the thickness of the container wall. For example, in other embodiments not shown, the toe 41 of the 1o preferred embodiment that protrudes from the annular leg 38 is absent. As described above, containers of the invention also incorporate stacking beads 16 that facilitate denesting and prevent the containers from being wedged within one another when they are nested. Specifically, the stacking bead prevents a top container from sliding all the way into and wedging or being stuck within the lower 15 container in which it is nested. Pursuant to the embodiments of the invention shown in FIGS. 1, 5, 6, and 9, 10, and 12, the stacking bead 16 is positioned between the lower and upper container walls 18, 20, and the lower container wall 18 is inwardly offset from the upper container wall 20. A top surface 42 of the stacking bead 16 extends from the upper container wall 20 20, and the bottom surface 28 of the stacking bead 16 extends from the lower container wall 18 and is shorter than the top surface 42 of the stacking bead 16. As a result, when a top container 30 is stacked on top of a lower container 32, the walls of the lower container 18, 20 push up against not only the stacking bead 16 (of the top container 30) but also against the upper container wall 20 of the top container 30. It is believed that 25 such a configuration reduces the shear stress that the stacking bead is subjected to and, thus, reduces potential deformation and failure of the stacking bead. Referring to FIGS. 5 and 12, showing the intersection of two nested containers, more detail in the structure can be seen. In particular, in a preferred embodiment shown in Fig. 12, a transitional chamber 19 can be used to precisely adapt 30 the diameter of the container to desired handling equipment, and can also serve the function of facilitating the function of the air passage vertical ribs 37. Pursuant to the embodiment of the invention shown in FIG. 7, the container bottom 34 is reinforced with continuous waffle ribbing 44 as opposed to only partial -9 waffle ribbing incorporated in containers known in the art. Containers known in the art are manufactured from blow molding, which entails inserting a tube of plastic within two halves of the mold and inserting an air tube near or on a pinch area of the mold. Air is then blown through the tube and expands the plastic to the outer periphery of the 5 mold. Those of skill in the art believe that the pinch area should be flat to facilitate inserting the air tube within the mold and that it would be unfeasible to use a non-flat pinch area. Ribbing, therefore, was never formed adjacent the pinch-area. Pursuant to the embodiment, however, it is believed that it is feasible to insert the air tube by a non-flat pinch area 46 that is adjacent to or on the ribbing 44. It is believed that the continuous 10 waffle ribbing 44 increases container bottom strength and reduces container bottom deformation. Pursuant to a second illustrative container of the invention shown in FIGS. 9 through 12, particularly suitable for formation through blow molding, a reinforced annular leg 38 is still formed along the container bottom 34. However, in this 15 embodiment, the reinforced leg 38 includes a thickness that is greater than the thickness of the container wall Tew, which is about 0.19 to about 0.25 inches thick in a preferred embodiment. In the preferred embodiment, the reinforced leg is defined by first and second thicknesses
T
aLI, TRa, both of which are greater than the thickness of the container wall, In one preferred embodiment, the first thickness TaLI is about two times 20 as thick as the container wall 18, 20 and is about 0.38 to about 0.5 inches thick; and, the second thickness Tu is about one and a half times as thick as the container wall 18, 20 and is about 0.29 inches to about 0.38 inches thick. Further, in the embodiment of FIGS. 9 and 11, there is a gap 40 between the reinforced leg 38 and other portions of the container bottom 34. The gap is defined by a 25 width T 0 that is not more than about five times as wide as the container wall thickness Tcw and, in a preferred embodiment, is about 0.75 inches wide. The height of the gap H 1 c is not more than about two times as thick as the container wall thickness Tcw and, in a preferred embodiment, is about 0.38 inches high. The increased thickness and material of the reinforced leg 38 allow the 30 reinforced leg to better withstand forces that it is subjected to when the container 10 is tipped on its side or rolled, when the entire weight of the container is bome by the leg. Those of skill in the art will appreciate that, although a particular shape and design of a reinforced annular leg 38 is shown, many other reinforced annular legs arc -10 covered by the scope of this invention that have a thickness greater than the thickness of the container wall. For example, in other embodiments not shown, the toe 41 of the preferred embodiment that protrudes from the annular leg 38 is absent. From the foregoing it will be observed that numerous modifications and 5 variations can be made to the invention without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or to be inferred. The disclosure is intended to cover all such modifications as fall within the scope of the invention. 10