WO 2012/031352 PCT/CA2011/001005 1 TITLE OF INVENTION BULK BIN 5 FIELD OF THE INVENTION This invention relates to bins, and in particular, to bulk bins for carrying and transporting items. 10 BACKGROUND OF THE INVENTION Bulk bins are used to carry and transport many different types of items, including food products such as fruit or produce. Conventional bulk bins are generally box-shaped structures with flat square or rectangular walls. Because the walls are flat, there is a need to 15 reinforce the strength of the walls and to prevent the bulk bins from bulging and splitting apart when they are filled with items. Ribs may be added to the walls, such as near the external corners, edges, and/or perimeter of the bulk bins in order to reinforce the overall strength of the bulk bins. In addition, one or more hollow columns may be incorporated into the corners of the bulk bins or along with middle of the walls. 20 However, because the walls of a conventional bulk bin are flat, the addition of columns will necessarily result in the columns either protruding from the interior or exterior surfaces of the walls. If the columns protrude on the exterior surfaces of the walls, this results in an increase in the overall dimensions of the bulk bin, but without any increase in the 25 interior capacity of the bulk bin. Consequently, the exterior columns lead to an inefficient use of space. If, however, the columns protrude on the interior surfaces of the walls, the columns will disrupt the smooth surfaces of the interior walls. This can result in bruising and damage 30 to the items placed in the bulk bin, especially if the items are delicate, such as fruits or vegetables.
WO 2012/031352 PCT/CA2011/001005 2 Therefore, there exists a need for a bulk bin that is structurally strong but does not require the addition of protruding columns on the interior or exterior surfaces of the walls of the bulk bin. 5 SUMMARY OF THE INVENTION The bulk bin according to the invention comprises four sides and a base. The interior of the bulk bin comprises a substantially smooth and continuous surface, without any sharp or abrupt corners or edges. Each of the sides comprises a top strip portion and a curved wall 10 portion. The top strip is substantially straight in the horizontal direction, whereas the curved wall portion is curved (in a concave manner) in the horizontal direction. A chamfer provides a smooth transition between the relative straightness of the top strip portion and the concavity of the curved wall portion, while maintaining the overall smooth and continuous interior surface of the bulk bin. 15 The curved wall portions of the sides contribute to the enhanced strength and rigidity of the bulk bin. The corner columns, which join the adjacent sides together, have a curved inner surface that continues the curvatures of the curved wall portions. 20 According to one aspect of the invention, the bin comprises a first side, a second side, a third side, a fourth side, and a base. The first side and the second side are attached to a first corner column. The second side and the third side are attached to a second corner column. The third side and the fourth side are attached to a third corner column. Finally, the fourth side and the first side are attached to a fourth comer column. The first side, the second side, 25 the third side, the fourth side, the first corner column, the second corner column, the third corner column, and the fourth corner column are all attached to the base. Each of the first side, the second side, the third side, and the fourth side comprises a top strip, a curved wall, and a chamfer. The top strip is substantially straight in a horizontal 30 direction. The chamfer is between the top strip and the curved wall and provides a substantially smooth and continuous transition surface between the top strip and the curved wall.
WO 2012/031352 PCT/CA2011/001005 3 In another aspect of the invention, each of the first comer column, the second comer column, the third corner column, and the fourth corner column comprises a corner surface. The corner surfaces are curved. 5 In yet another aspect of the invention, each of the corner surfaces join, in a smooth and continuous manner, with an inner surface of two curved walls of adjacent ones of the first side, the second side, the third side, and the fourth side. In still another aspect of the invention, each of the curved walls comprises a curvature 10 in a horizontal direction. The curvature is concave, as from within the bin. In another aspect of the invention, each of the first side, the second side, the third side and the fourth side comprises a plurality of horizontal ribs. The horizontal ribs extend away from an outer surface of the first side, the second side, the third side, and the fourth side. 15 In still another aspect of the invention, the chamfers' heights vary along the chamfers' lengths. The chamfers' heights are greatest at a middle of the chamfers' longitudinal axes. The chamfers' heights are least near an end of the chamfers' longitudinal axes. The chamfers are substantially semi-elliptical in shape. 20 In a further aspect of the invention, the curved walls and/or the base comprise a plurality of vents. The base comprises a curved top surface, with the curved top surface being concave, as from within the bin. 25 In another aspect of the invention, the first corner column, the second corner column, the third corner column, and the fourth comer column are substantially exterior to the curved walls of the first side, the second side, the third side, and the fourth side. In yet another aspect of the invention, the base comprises a plurality of supports 30 extending away from the bin's bottom. The bin further comprises a plurality of feet, wherein one of each of the feet is fitted upon each one of the supports. In another aspect of the invention, a bin comprises a first side, a second side, a third said, a fourth side, and a base. The first side and the second side are attached to a first corner WO 2012/031352 PCT/CA2011/001005 4 column. The second side and the third side are attached to a second corner column. The third side and the fourth side are attached to a third corner column. Finally, the fourth side and the first side are attached to a fourth corner column. The first side, the second side, the third side, the fourth side, the first corner column, the second corner column, the third corner 5 column, and the fourth corner column are all attached to the base. Each of the first side, the second side, the third side, and the fourth side comprises a curved wall. Each of the first comer column, the second comer column, the third corner column, and the fourth corner column comprises a curved corner surface. Each of the curved 10 corner surfaces join, in a smooth and continuous manner, with an inner surface of two curved walls of adjacent ones of the first side, the second side, the third side, and the fourth side. The foregoing was intended as a broad summary only and of only some of the aspects of the invention. It was not intended to define the limits or requirements of the invention. 15 Other aspects of the invention will be inferred from the detailed description of the preferred embodiment and the claims. BRIEF DESCRIPTION OF THE DRAWINGS 20 The invention will be described by reference to the detailed description of the preferred embodiment and to the drawings thereof in which: Fig. 1 is a top perspective view of the bulk bin according to the preferred embodiment; 25 Fig. 2 is an exploded bottom perspective view of the bulk bin; Fig. 3 is a side view of the bulk bin; 30 Fig. 4 is a front view of the bulk bin; Fig. 5 is a bottom view of the bulk bin; Fig. 6 is a top view of the bulk bin; WO 2012/031352 PCT/CA2011/001005 5 Fig. 7 is another front view of the bulk bin; Fig. 8 is a cross-sectional slice of Fig. 7, taken along line A-A; 5 Fig. 9 is a cross-sectional slice of Fig. 7, taken along line B-B; Fig. 10 is a cross-sectional slice of Fig. 7, taken along line C-C; 10 Fig. 11 is another top perspective view of the bulk bin; Fig. 12 is another top view of the bulk bin; Fig. 13 is a cross-sectional slice of Figs. 11 and 12, taken along line A-A; 15 Fig. 14 is a cross-sectional slice of Figs. 11 and 12, taken along line B-B; Fig. 15 is a cross-sectional slice of Figs. 11 and 12, taken along line C-C; 20 Fig. 16 is a magnified view of Fig. 13, taken at A; Fig. 17 is a magnified view of Fig. 14, taken at B; Fig. 18 is a magnified view of Fig. 15, taken at C; and 25 Fig. 19 is a cutaway view of the bulk bin. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 30 Referring to Figs. 1 to 6, the bulk bin 10 of the present invention comprises a base 20 with a first side 30, a second side 32, a third side 34, and a fourth side 36. The first, second, third, and fourth sides 30, 32, 34, and 36 are preferably substantially rectangular in overall shape; however, portions of the sides 30, 32, 34, and 36 are curved (as described later). Preferably, a number of vents 90 are cut into the first, second, third, and fourth sides 30, 32, WO 2012/031352 PCT/CA2011/001005 6 34, and 36 and the base 20. The first side 30 and the second side 32 are joined at a first corner column 40. The second side 32 and the third side 34 are joined at a second comer column 42. The third side 34 and the fourth side 36 are joined at a third corner column 44. The fourth side 36 and the first side 30 are joined at a fourth corner column 46. 5 Each of the sides 30, 32, 34, and 36 preferably comprises a wall portion and a top strip portion, with a chamfer portion in between the two portions. For example, the first side 30 comprises a first wall 31, a first strip 60, and a first chamfer 70. The second side 32 comprises a second wall 33, a second strip 62, and a second chamfer 72. The third side 34 10 comprises a third wall 35, a third strip 64, and a third chamfer 74. The fourth side 36 comprises a fourth wall 37, a fourth strip 66, and a fourth chamfer 76. The first strip 60 extends horizontally between the first corner column 40 and fourth corner column 46 and preferably extends vertically to the top of the bulk bin 10. The second 15 strip 62 extends horizontally between the first comer column 40 and the second corner column 42 and preferably extends vertically to the top of the bulk bin 10. The third strip 64 extends horizontally between the second corner column 42 and the third corner column 44 and preferably extends vertically to the top of the bulk bin 10. Meanwhile, the fourth strip 66 extends horizontally between the third corner column 44 and the fourth corner column 46 and 20 preferably extends vertically to the top of the bulk bin 10. Each of the first, second, third, and fourth strips 60, 62, 64, and 66 are substantially straight in the horizontal direction. The first, second, third, and fourth walls 31, 33, 35, and 37 lie below the first, second, third, and fourth strips 60, 62, 64, and 66 respectively and are substantially curved in the 25 horizontal direction (as described later). The chamfers 70, 72, 74, and 76 provide a transition between the substantially straight strips 60, 62, 64, and 66 and the substantially curved walls 31, 33, 35, and 37. For example, the first chamfer 70 lies between the first strip 60 and the first wall 31. The second chamfer 72 lies between the second strip 62 and the second wall 33. The third chamfer 74 lies between the third strip 64 and the third wall 35. Meanwhile, the 30 fourth chamfer 76 lies between the fourth strip 66 and the fourth wall 37. A number of ribs extend, substantially horizontally and outwardly, away from the top portions of the sides 30, 32, 34, and 36. For example, a number of first ribs 61 extend from the top portion of the first side 30. Most of the first ribs 61 extend away from the first strip WO 2012/031352 PCT/CA2011/001005 7 60; however, depending on the location of the first ribs 61 on the side 30, a portion of the first ribs 61 may extend away from the first chamfer 70 or the first wall 31. Similarly, a number of second ribs 63 extend from the top portion of the second side 32. Most of the second ribs 63 extend away from the second strip 62; however, a portion of the second ribs 63 may 5 extend away from the second chamfer 72 or the second wall 33. A number of third ribs 65 extend from the top portion of the third side 34. Most of the third ribs 65 extend away from the third strip 64; however, a portion of the third ribs 65 may extend away from the third chamfer 74 or the third wall 35. Finally, a number of fourth ribs 67 extend from the top portion of the fourth side 36. Most of the fourth ribs 67 extend away from the fourth strip 66; 10 however, a portion of the fourth ribs 67 may extend away from the fourth chamfer 76 or the fourth wall 37. In the preferred embodiment, each of the first, second, third, and fourth ribs 61, 63, 65, and 67 comprises four horizontal ribs, but other numbers of ribs may also be used. The first, second, third, and fourth sides 30, 32, 34, and 36 and the first, second, third, 15 and fourth corner columns 40, 42, 44, and 46 form a frame, with the bottom edges of the frame attached to the base 20 and the top edges of the frame forming an opening for the bulk bin 10. This opening is preferably rectangular in shape. In an alternate embodiment, the opening is square. 20 The first side 30 and the base 20 are joined at a first base comer 50. The second side 32 and the base 20 are joined at a second base corner 52. The third side 34 and the base 20 are joined at a third base corner 54. The fourth side 36 and the base 20 are joined at a fourth base comer 56. The first, second, third, and fourth corner columns 40, 42, 44, and 46 are also joined to the base 20. Preferably, the first side 30 and the second side 32 are substantially 25 perpendicular to one another; the second side 32 and the third side 34 are substantially perpendicular to one another; the third side 34 and the fourth side 36 are substantially perpendicular to one another; and the fourth side 36 and the first side 30 are substantially perpendicular to one another. 30 Referring to Figs. 2 and 5, preferably, one or more sockets 80 project downwards from the bottom surface of the base 20, as best seen in Fig. 2. Each of the sockets 80 may be fitted with a foot 82. The feet 82, when fitted onto the sockets 80, runs substantially along the length of the bottom of the sockets 80. The sockets 80 and the feet 82 raise the base 20 off the ground and allow for convenient lifting of the bulk bin 10 by forklifts. The feet 82 WO 2012/031352 PCT/CA2011/001005 8 also serve to protect the sockets 80 and the base 20 from impact damage, abrasion, and dirt ingress. The first corner column 40 comprises a first corner surface 41 that is formed on the 5 inner surface of the first corner column 40, facing the interior of the bulk bin 10. Similarly, second, third, and fourth corner surfaces 43, 45, and 47 are formed on the inner surfaces of the second, third, and fourth corner columns 42, 44, and 46, respectively. The corner columns 40, 42, 44, and 46 are externalized with respect to the sides 30, 10 32, 34, and 36; that is, the corner columns 40, 42, 44, and 46 are on substantially the outside of the sides 30, 32, 34, and 36 and do not protrude into the interior of the bulk bin 10. Further, the corner columns 40, 42, 44, and 46 preferably form four corners of a rectangle. The perimeter of this rectangle can be formed by extending imaginary lines from the exterior sides of each of the comer columns 40, 42, 44, and 46 to those of its neighbouring corner 15 columns 40, 42, 44, and 46 (e.g. extending an imaginary line from the exterior sides of the first corner column 40 to the exterior side of the second comer column 42 and to the exterior side of the fourth corner column 46). Preferably, the walls 31, 33, 35, and 37 all lie substantially within this perimeter. 20 Referring to Fig. 6, the interior of the bulk bin 10 is a substantially continuous, smooth surface. The interface of the first wall 31, the second wall 33, and the first corner surface 41 is a substantially continuous, smooth surface. The curvature of the first corner surface 41 meets with the first wall 31 and the second wall 33 in a continuous manner, without any sharp corners or edges. Similarly, the interface of the second wall 33, the third 25 wall 35, and the second corner surface 43 is a substantially continuous, smooth surface. The interface of the third wall 35, the fourth wall 37, and the third corner surface 45 is a substantially continuous, smooth surface. The interface of the fourth wall 37, the first wall 31, and the fourth comer surface 47 is a substantially continuous, smooth surface. 30 In addition, the interface of the first wall 31 and the base 20 (via the first base corner 50) is a substantially smooth and continuous surface. The interface of the second wall 33 and the base 20 (via the second base comer 52) is a substantially smooth and continuous surface. The interface of the third wall 35 and the base 20 (via the third base corner 54) is a substantially smooth and continuous surface. The interface of the fourth wall 37 and the base WO 2012/031352 PCT/CA2011/001005 9 20 (via the fourth base corner 56) is a substantially smooth and continuous surface. Preferably, the base 20 comprises a slight curvature on its upper surface (i.e. the surface facing the interior of the bulk bin 10) such that the depth of the interior of the bulk bin 10 is greatest near the centre and least near the interfaces of the base 20 with the walls 31, 33, 35, 5 and 37. Furthermore, the interface of the first comer surface 41 with the base 20 is also a substantially smooth and continuous surface. The interface of the second corner surface 43 with the base 20 is a substantially smooth and continuous surface. The interface of the third 10 corner surface 45 with the base 20 is a substantially smooth and continuous surface. Finally, the interface of the fourth corner surface 47 with the base 20 is a substantially smooth and continuous surface. Referring to Figs. 7 to 10, Figs. 8 to 10 show cross-sectional slices of the bulk bin 10 15 of Fig. 7 at various vertical levels. As seen in Figs. 8 to 10, much of the comer columns 40, 42, 44, and 46 are on the exterior of the sides 30, 32, 34, and 36, with only corner surfaces 41, 43, 45, and 47 part of the interior surface of the bulk bin 10. Fig. 8 shows the cross-sectional slice of the portion of the bulk bin 10 where the strips 20 60, 62, 64, and 66 are located (at line A-A). As shown in Fig. 8, the strips 60, 62, 64, and 66 are substantially straight in the horizontal direction, resulting in straight edges along the sides 30, 32, 34, and 36. The comer surfaces 41, 43, 45, and 47 are curved to provide for a substantially smooth transition between the adjacent sides 30, 32, 34, and 36. 25 Fig. 9 shows the cross-sectional slice of the portion of the bulk bin 10 below the strips 60, 62, 64, and 66 and in the region where the chamfers 70, 72, 74, and 76 meet with the walls 31, 33, 35, and 37 (at line B-B). The corner surfaces 41, 43, 45, and 47 remain curved. In addition, the sections of the sides 30, 32, 34, and 36 near the corner surfaces 41, 43, 45, and 47 are more curved (in comparison with the cross-sectional slice of Fig. 8). These curved 30 sections represent the curvature of the portions of the walls 31, 33, 35, and 37 present in the particular cross-sectional slice. The middle portions of the sides 30, 32, 34, and 36 in Fig. 9 are substantially straight and represent the portions of the chamfers 70, 72, 74, and 76 present in the particular cross-sectional slice.
WO 2012/031352 PCT/CA2011/001005 10 Fig. 10 shows the cross-sectional slice of the portion of the bulk bin 10 through the walls 31, 33, 35, and 37 (at line C-C). The comer surfaces 41, 43, 45, and 47 remain curved. In this region, the sides 30, 32, 34, and 36 are further curved (in comparison with Figs. 8 and 9). These curved sections represent the full curvature of the walls 31, 33, 35, and 37 (since 5 the chamfers 70, 72, 74, and 76 are not present in this region). Preferably, the degree of curvature of the walls 31, 33, 35, and 37 is substantially constant throughout the height of the walls 31, 33, 35, and 37; however, variation in the degree of curvature is also possible. Although the walls 31, 33, 35, and 37 are curved, they still lie within the perimeter formed by the corner columns 40, 42, 44, and 46. 10 The curvatures of the walls 31, 33, 35, and 37 in the horizontal direction act to strengthen the sides 30, 32, 34, and 36 and to prevent the bulk bin 10 from bulging when items are packed into the bulk bin 10. By utilizing these curvatures, there is no longer the need for reinforcing columns to be placed vertically at the middle of the sides 30, 32, 34, and 15 36. Such reinforcing columns may reduce the efficient use of space or damage items in the bulk bin 10 (if present on the interior of the sides 30, 32, 34, and 36). Because the curvatures of the walls 31, 33, 35, and 37 act to strengthen the sides 30, 32, 34, and 36, the sides 30, 32, 34, and 36 are not required to be as thick as if they were completely planar. As a result, less material is required to construct the bulk bin 10, and the overall bulk bin 10 is lighter. 20 Another reason why less material is required is because reinforcing columns are no longer required. In addition, the curvatures of the walls 31, 33, 35, and 37 allow for a shallower curvature of the corner surfaces 41, 43, 45, and 47. If the walls 31, 33, 35, and 37 were not 25 curved, then the corner surfaces 41, 43, 45, and 47 (in order to produce a smooth and continuous interface) would need to transition between two perpendicular surfaces. However, since the walls 31, 33, 35, and 37 are curved, adjoining walls (e.g. first wall 31 and second wall 33; second wall 33 and third wall 35; third wall 35 and fourth wall 37; and fourth wall 37 and first wall 31) are already curved towards each other and therefore, the corner 30 surfaces 41, 43, 45, and 47 are not required to transition between surfaces that are abrupt. This shallower curvature of the corner surfaces 41, 43, 45, and 47 allows for a more gradual curvature in the corners of the bulk bin 10.
WO 2012/031352 PCT/CA2011/001005 11 Referring to Figs. 11 to 18, cross-sectional slices of the bulk bin 10 at various vertical sections are depicted. The cross-sectional slices show the arrangement of the sides 30, 32, 34, and 36 and in particular, the ribs 61, 63, 65, and 67 at various vertical locations. Figs. 13 and 16 depict cross-sectional slices of the bulk bin 10 at line A-A of Figs. 11 and 12, which 5 cuts through first side 30 and third side 34 near the left end of the bulk bin 10. As shown in Fig. 13, the first ribs 61 and the third ribs 65 extend outwardly from the outer surface of the first side 30 and the third side 34, respectively. Referring to Fig. 16 (which is a magnified view of Fig. 13 at A), the third wall 35 extends substantially vertically. The third chamfer 74 joins the third wall 35 with the third strip 64. Much of the third ribs 65 extend from the third 10 strip 64. However, because at this region of the bulk bin 10 the third chamfer 74 is relatively short, a portion of the third ribs 65 extends from the third wall 35. Substantially all of the third ribs 64 lie outward of the third wall 35. Figs. 14 and 17 depict cross-sectional slices of the bulk bin 10 at line B-B of Figs. 11 15 and 12, which cuts through first side 30 and third side 34 approximately one-third of the way from the left end of the bulk bin 10. As shown in Fig. 14, the first ribs 61 and the third ribs 65 still extend outwardly from the outer surface of the first side 30 and the third side 34, respectively. However, referring to Fig. 17 (which is a magnified view of Fig. 14 at B), in this region of the bulk bin 10 the third chamfer 74 is longer (compared to that in Fig. 16), a 20 portion of the third ribs 65 now extend from the third chamfer 74 and not from the third wall 35. The third ribs 65 are also now partially sunken in, in relation to the third wall 35. Figs. 15 and 18 depict cross-sectional slices of the bulk bin 10 at line C-C of Figs. 11 and 12, which cuts through first side 30 and third side 34 approximately halfway along the 25 length of the bulk bin 10. As shown in Fig. 15, the first ribs 61 and the third ribs 65 still extend outwardly from the outer surface of the first side 30 and the third side 34, respectively. However, referring to Fig. 18 (which is a magnified view of Fig. 15 at C), in this region of the bulk bin 10 the third chamfer 74 is at its longest. More of the third ribs 65 extend from the third chamfer 74 (compared to Figs. 16 and 17). The third ribs 64 are now substantially 30 sunken in, in relation to the third wall 35. Fig. 19 is a cut-away view of the bulk bin 10 that shows the curvatures of the second side 32 and the fourth side 36. Although Figs. 11 to 19 may only depict the curvatures of some of the sides 30, 32, 34, and 36 (in particular, the first side 30 and third side 34), it is WO 2012/031352 PCT/CA2011/001005 12 understood that all of the sides 30, 32, 34, and 36 have substantially similar curvatures and features. As seen in Figs. 11 to 19, each of the chamfers 70, 72, 74, and 76 lies between one of 5 the strips 60, 62, 64, and 66 and the corresponding one of the walls 31, 33, 35, and 37. Preferably, the chamfers 70, 72, 74, and 76 are substantially semi-elliptical in shape, with the height (or depth) of the chamfers 70, 72, 74, and 76 the greatest near the middles of each of the sides 30, 32, 34, and 36 and the least near the corner columns 40, 42, 44, and 46. The chamfers 70, 72, 74, and 76 provide a substantially smooth and continuous transition surface 10 between the curved walls 31, 33, 35, and 37 and the straight (in the horizontal direction) strips 60, 62, 64, and 66. By providing a substantially smooth and continuous transition surface, the strength of the bulk bin 10 is improved by eliminating stress points typically found in sharp corners or edges. 15 Preferably, the bulk bin 10 has an overall, external rectangular box arrangement (formed by the relatively straight edges of the exterior of the corner columns 40, 42, 44, and 46, the base 20, and the strips 60, 62, 64, and 66). However, within this external rectangular box arrangement, the interior of the bulk bin 10 is substantially curved (from the walls 31, 33, 35, and 37, the curvature of the top surface of the base 20, the corner surfaces 41, 43, 45, and 20 47, and the base corners 50, 52, 54, and 56). The has the benefits of allowing multiple bulk bins 10 to be stacked or packed next to each other in an efficient manner, while still providing the benefits of a smooth interior surface. In an alternate embodiment, instead of a rectangular box arrangement, the bulk bin 10 has an overall cube arrangement (i.e. the sides 30, 32, 34, and 36 and the base 20 are substantially square in overall shape). 25 In the preferred embodiment, the length of the bulk bin 10 is approximately 1,200 mm, with a width of approximately 1,000 mm, and a height of approximately 800 mm. However, other dimensions are also possible. In the preferred embodiment, the curvatures of the corner surfaces 41, 43, 45, and 47 have a radius of approximately 112 mm. The 30 curvatures of the walls 31, 33, 35, and 37 have a radius of approximately 3,393 mm. The curvatures of the base corners 50, 52, 54, and 56 have a radius of approximately 40 mm, and the curvature of the base 20 has a radius of approximately 12,000 mm. Other degrees of curvature are also possible, as long as it results in a substantially smooth interior surface for the bulk bin 10 without any abrupt edges or corners.
WO 2012/031352 PCT/CA2011/001005 13 The smooth interior surfaces of the bulk bin 10 (because of the relative curvatures of the walls 31, 33, 35, and 37; the corner surfaces 41, 43, 45, and 47; the base corners 50, 52, 54, and 56; the chamfers 70, 72, 74, and 76; and the base 20) results in less damage to items 5 stored in the bulk bin 10. For example, items in the bulk bin 10 will not come into contact with any abrupt corners or edges and will not come into contact with interior reinforcing columns. These various curvatures also further strengthen the rigidity of the bulk bin 10 as they eliminate stress points present in sharp corners or edges. Also, the propensity for the bulk bin 10 to bulge (and subsequently contract) is reduced. 10 Although the preferred embodiment shows chamfers 70, 72, 74, and 76 providing a transition surface between the curved walls 31, 33, 35, and 37 and the straight strips 60, 62, 64, and 66, in an alternative embodiment, the chamfers 70, 72 74, and 76 may be omitted. In this embodiment, the bulk bin 10 will still have a curved surface for most of the interior (i.e. 15 from the walls 31, 33, 35, and 37 and the corner surfaces 41, 43, 45, and 47). In a further embodiment, the strips 60, 62, 64, and 66 may be omitted as well, in which case the horizontal ribs 61, 63, 65, and 67 may extend away from the walls 31, 33, 35, and 37 solely. Furthermore, the curvature of the walls 31, 33, 35, and 37 may result in better air 20 circulation about the bulk bin 10. Air impacting the side of the bulk bin 10 more readily enters the vents 90 because the air impacts a curved surface, rather than a straight, planar surface. The curved surfaces also results in a more turbulent flow of air, facilitating a mixing of the air. 25 Preferably, the bulk bin 10 is made from a polypropylene or polyethylene material. The bulk bin 10 may be made as a single, unitary piece by injection molding. If the bulk bin 10 comprises sockets 80 and feet 82, the feet 82 may be produced separately and fitted to the sockets 80 after production of the rest of the bulk bin 10. 30 It will be appreciated by those skilled in the art that the preferred and alternative embodiments have been described in some detail but that certain modifications may be practiced without departing from the principles of the invention.