US20040026435A1

US20040026435A1 - Storage container with blow molded inverted rim and ergonomic handle

Info

Publication number: US20040026435A1
Application number: US10/444,312
Authority: US
Inventors: Erik Skov; William Shepler; Gina Rodi; Tony Marchetta
Original assignee: Rubbermaid Inc
Current assignee: Rubbermaid Inc
Priority date: 2002-05-23
Filing date: 2003-05-23
Publication date: 2004-02-12
Also published as: AU2003234654A1; WO2003099666A2; WO2003099666A3; WO2003099666B1

Abstract

A storage container includes a bottom wall, a pair of side walls extending up from the bottom wall, and a pair of end walls extending up from the bottom wall, the bottom wall, side walls, and end walls being interconnected and defining a cargo space. A side rim is disposed on top of the side walls and includes a bottom portion extending outwardly from the side wall and an arch extending upward and downward from the bottom portion. The arch defines a convex upper surface and a concave interior arch surface. A middle portion extends upwardly from the arch, an upper portion extends inward from the middle portion, and a lip extending downward from the upper portion and outside of the cargo space. A plurality of spaced apart ribs extend downward from and traverse the concave interior arch surface.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. [0001] Provisional Application 60/382,749, filed May 23, 2002.

TECHNICAL FIELD

An improved reusable plastic storage container is disclosed. More specifically, a blow molded reusable plastic storage container is disclosed which includes one or more of an inverted upper rim spaced laterally outside of the interior storage space and an ergonomically designed handle.

DESCRIPTION OF RELATED ART

Reusable storage containers are known. One common type of reusable storage container is fabricated from molded plastic in the form of an open-top box with a molded plastic lid. Such containers come in a variety of styles and colors.

Reusable plastic storage containers are typically made from one of two processes—injection molding or blow molding. An example of an injection molded reusable storage container is illustrated in FIGS. 1 and 2. FIG. 1 is a partial sectional view of a

container

30 defining a cargo space 32 with a bottom panel 34 connected to a side panel 36 which, in turn, is connected to a continuous outer rim 38. The rim 38 extends laterally outward from the side panel 36 and cargo space 32. A horizontal surface 40 is provided for engaging a top (not shown) and a downwardly protruding lip 42 can be used either to engage a lid latching mechanism or as a grip or handle. Due to the structure of the rim 38 and, specifically, the thickness of a lateral portion 44 (see FIG. 2), the container 30 must be fabricated using an injection molded process. While injection molding is suitable for providing high quality reusable storage containers, injection molding is relatively slow and not cost effective.

Blow molding is faster than injection molding but, as shown in FIGS. 3-5, blow molded designs present a different set of problems. A first blow molded reusable storage container 50 is illustrated in FIG. 3. The container 50 includes a bottom panel 52, connected to a side panel 54 which, at its upper end, includes a continuous outer rim 56. The outer rim terminates at an inwardly extending lip 58 which is disposed laterally inward from at least one portion of the side panel 54 and therefore infringes on the amount of available storage space provided by the container 50. Further, the inwardly extending lip 58 is sharp and therefore can scratch or cause injury to the user's hands or to material being stored in or removed from the container 50. Further, the structure of the rim 56 does not lend itself to an acceptable sealing engagement with a top or lid (not shown). Also, a blow molded container heretofore could not achieve a lip as in FIGS. 1 and 2.

A second blow molded

storage container

60 is shown in FIGS. 4-5. The second container 60 includes a side panel 62 connected to an upper rim 64 which changes in configuration as it extends around the four sides of the container. The smaller configuration is shown at 64 a. Again, both rims 64, 64 a terminate at inwardly extending lips 66 which, although avoiding extending into the available storage space, the lips 66 are sharp and therefore ergonomically undesirable.

Further, currently available reusable storage containers do not include ergonomically acceptable handles. Specifically, handles available with currently available reusable storage containers are often difficult to grasp and do not allow enough space for fingers to grasp the handle. The handles may include sharp edges or pinch points which can dig into the user's hand and cause discomfort, especially given the fact that most reusable storage containers have a five gallon or greater capacity and, when laden with heavy objects such as books, are heavy and difficult to the move.

Further, reusable storage containers with handles must be fabricated with an injection molding process as current technology or designs have not been developed which would enable a suitable handle for a five gallon or greater size container using a more efficient blow molding process.

SUMMARY OF THE DISCLOSURE

A more economical and ergonomic reusable three-dimensional storage container is disclosed that can meet the need for a plastic reusable storage container that can be manufactured using a more cost efficient process than injection molding but that avoids the limitations and problems presented by previous blow molding designs. Further, the disclosed storage container meets the need for an ergonomically designed handle that can be manufactured using a more cost efficient process than injection molding.

One disclosed storage container comprises a bottom panel connected to and disposed between two opposing side panels and two opposing end panels. Each side panel is disposed between and connected to the opposing end panels to form an open top box structure with an interior storage space. The two opposing side panels and two opposing end panels form a continuous upper rim. The upper rim provides an upper flat engagement surface that terminates in a downwardly protruding lip. More specifically, the upper rim comprises a lower section, a middle section and a top section. The lower section is connected to one of the opposing end or side panels and extends laterally away from the panel or the cargo space before being connected to the middle section. The middle section extends upward from the lower section to the upper section. The upper section extends laterally inward towards the storage space that terminates at a downwardly protruding lip disposed laterally outward from a point of connection between the lower section and side or end panel and laterally outward from the storage space defined by the side and end panel. The lip protrudes downwardly as opposed to laterally and therefore does not normally engage a user's hands or the goods being placed into or removed from the container.

In a refinement, the upper rim along the side panel includes an arch that opens downward in between the lower section and the upper section. A plurality of ribs can be disposed within the arch to provide strength and stability to-the rim.

In a refinement, the storage container also includes handles disposed on the end panels. Each handle comprises a hollow tube with two ends connected to its respective end panel. A portion of the hollow tube is spaced apart from the respective end panel defining a finger space disposed between the hollow tube and the end panel. The portion of the hollow tube that is spaced apart from the end panel has a smooth profile with no sharp edges which would cause discomfort when lifting the container when it is full of heavy articles.

In a refinement, the upper section of the rim is substantially horizontal to provide an engagement or sealing surface with a top or lid.

The containers may be formed by a blow molding process, a continuous blow molding process or a co-extrusion blow molding process. In a further refinement, the container is fabricated from a polymeric material selected from the group consisting of polypropylene, polyethyleneterepthalate, polyvinylchloride, polycarbonate and mixtures thereof.

Other advantages of the disclosed container and methods will be apparent to those skilled in the art from a review of the following figures and detailed description taken in conjunction with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed containers are described diagrammatically in the following drawings wherein: [0016]
FIG. 1 is a partial sectional view of a reusable storage container made by a conventional injection molding process; [0017]
FIG. 2 is an enlarged sectional view of the upper rim of the container shown in FIG. 1; [0018]
FIG. 3 is a partial sectional view of a reusable storage container made by a conventional blow molding process; [0019]
FIG. 4 is a partial sectional view of a reusable storage container made by a conventional blow molding process; [0020]
FIG. 5 is another sectional view of the upper rim of the container shown in FIG. 4; [0021]
FIG. 6 is an elevational view of a blow molded reusable storage container made in accordance with this disclosure; [0022]
FIG. 7 is a top view of the storage container shown in FIG. 6; [0023]
FIG. 8 is an end view of the storage container shown in FIG. 6; [0024]
FIG. 9 is a fragmentary cross-sectional view of the handle and upper rim of the storage container taken along line [0025] 9-9 in FIG. 8.
FIG. 10 is a perspective view of the handle section in FIG. 8, partially cut away. [0026]
FIG. 11 is a fragmentary elevational view from inside of the blow molded reusable storage container of the upper rim of the storage container, taken along line [0027] 11-11 in FIG. 7.
FIG. 12 is a fragmentary cross-section view of the side rim of the storage container taken along line [0028] 12-12 in FIG. 11.
FIG. 13 is a fragmentary cross-sectional view of the side rim of the strorage container taken along line [0029] 13-13 in FIG. 11.
FIG. 14 is a fragmentary cross-sectional view of the side rim of the storage container taken along line [0030] 14-14 in FIG. 12.
FIG. 14[0031] a is a perspective view of a portion of the side rim, viewed from underneath and particularly showing the ribbing, of the storage container.
FIG. 15 is a perspective view of a movable blow-molding apparatus configured to produce the storage container, the moving section being in the raised position. [0032]
FIG. 16 is a front elevational view of the apparatus of FIG. 15. [0033]
FIG. 17 is a front view of the moving section of the apparatus. [0034]
FIG. 18 is a fragmentary cross-sectional view taken along line [0035] 18-18 in FIG. 16, and showing the side rim forming portion.
FIG. 19 is a fragmentary cross-sectional view of the handle forming portion of the mold, the moving section being in a lowered position, after receiving the resin, and taken along circle [0036] 19 in FIG. 15.
FIG. 20 is a fragmentary cross-sectional view of the handle forming portion of the mold, the moving section being in a raised position, after the molding process is complete, and taken along circle [0037] 19 in FIG. 15.
FIG. 21 is a fragmentary cross-sectional view of the side rim forming portion of the mold, the moving section being in a lowered position, after receiving the resin, and taken along [0038] circle 21 in FIG. 16.
FIG. 22 is a fragmentary cross-sectional view of the side rim forming portion of the mold, the moving section being in a raised position, after the molding process is complete, and taken along [0039] circle 21 in FIG. 16.
FIG. 23 is a fragmentary cross-sectional view of the side rim forming portion of the mold, the moving section being in a lowered position, after receiving the resin, and taken along [0040] circle 21 in FIG. 16.
FIG. 24 is a fragmentary cross-sectional view of the side rim forming portion of the mold, the moving section being in a raised position, after the molding process is complete, and taken along [0041] circle 21 in FIG. 16.
The drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the disclosed containers or which may render other details difficult to perceive may have been omitted. It should be understood, of course, that the disclosure is not necessarily limited to the particular embodiments illustrated herein. [0042]

DETAILED DESCRIPTION

General [0043]
A [0044] reusable storage container 70, constructed in accordance with the teachings of this disclosure, is illustrated in FIGS. 6-14. Referring to FIGS. 6-8, the container 70 includes a bottom panel 72 disposed between and connected to opposing side panels 74, and includes two opposing end panels 76. The side panels 74, bottom panel 70, and end panels 76 define a cargo space 78 therein. The container 70 also includes handles 80 extending out from the end panels 76. The end panels 76, as well as the side panels 74, may include a number of recesses 82 and/or ribs (not shown). The ribs and recesses 82 enhance the structural integrity of the container 70 and also enhance the stackability of the container 70 with other like containers 70. Further, any one or more of the recesses 82 may also provide a transparent window (not shown) which enables the consumer to view the contents of the container 70 without removing a top or lid or moving the container 70 from a shelf or other stored position.
Rim [0045]
The tops of the respective two opposing [0046] side panels 74 and two opposing end panels 76 form a continuous, inverted upper rim 84. In the region of the handles 80, the upper rim 84 takes on the configuration of the end rim 86, shown in cross section in FIG. 9. On the side panels 74, the upper rim 84 takes on the configuration of the side rim 88, shown in a front view in FIGS. 11 and 14, in cross-section in FIGS. 12 and 13, and in perspective in FIG. 14a. Thus, the end rims 86 and side rims 88 are portions of the upper rim 84.
Referring now to FIG. 9, each end rim [0047] 86 includes an end lower section 90 connected to one of the respective end panels 76 at connection point or joint 92. The end lower section 90 extends generally outward in an angled fashion and away from the cargo space 78 before being connected to an end middle section 94. The end middle section 94 extends generally upward from the end lower section 90 before being connected to an end upper section 96, and includes a first middle section 98 and a second middle section 100. The end upper section 96 extends generally laterally inward toward the cargo space 78 and terminates in a downwardly protruding lip 102. The lip 102 can be positioned at or laterally outward from the joint 92 where the end lower section 90 of the end rim 86 is connected to one of the end panels 76.
The end rim [0048] 86 provides a flat upper engagement surface 104 in the end upper section 96 for sealing against a top or a lid 106. Further, by including the lip 102 in a downwardly extending position, spaced outward relative to a plane of the end panels 76 and away from the cargo space 78, the lip 102 not only does not infringe on the available storage space but its generally vertical downward orientation prevents the lip 102 from scratching or otherwise engaging the user's hands or arms or the material being stored in or removed from the container 70.
The end rim [0049] 86 further includes a lid receiver 108. The lid receiver 108 may be a recess in the end middle section 94. The lid 106 may include a protrusion 110 adapted to extend into the receiver 108, thereby holding the lid 106 under tension in the lid receiver 108 and against the upper engagement surface 104 and sealing the cargo space 78. The lid 106 can also include a tab 112 such that a user can grasp the lid tab 112, pull the protrusion 110 out of the receiver 108, and remove the lid 106 from the container 70 to reveal and access the cargo space 78.
Referring now to FIG. 11, the inside of a [0050] side panel 74, showing especially the side rim 88, is depicted. As can be seen in FIGS. 12 and 13, the side rim 88 includes a side lower section 116 connected to one of the respective side panels 74 at a transition point or curve 118. The side lower section 116 angles generally outward from the cargo space 78.
Connected to the side [0051] lower section 116 is a ribbed section 120. The ribbed section 120 includes an arch 122 that extends upward from the side lower section 116 and back down again. As seen in FIGS. 12 and 13, the arch 122 includes a convex surface 124. As seen in FIG. 13, the arch 122 includes a concave surface 126, and a top point 128 on the concave surface 126. A spaced apart series of ribs 130 (seen best in FIG. 13 and 14 a) are disposed along the length of and interior to the arch 122 as it traverses the upper rim 84 on its concave surface 126 and extend in a downward fashion from the top point 128. The ribs 130 are oriented generally perpendicular to the concave surfaces 126 of the arch 122 and traverse the area within the arch with plastic or resin 132 and serve to increase the strength of the upper rim 84.
The ribbed [0052] section 120 is connected to a side middle section 134. The side middle section 134 extends generally upward from al ledge 135 which extends outward from a lower outer end of the ribbed section 130. The side middle section 134 further includes a shoulder 138 that extends inward. A side upper section 136 is connected to the side middle section 134. The side upper section 136 extends generally inward back toward the cargo space 78 and defines a flat upper engagement surface 140 and terminates in a downwardly protruding lip 142. The lip 142 can be positioned at or laterally outward from the transition point or curve 118 where the side lower section 116 is connected to one of the side panels 74. Again, by including the downwardly protruding lip 142 in a position spaced outward from the plane of the side panels 74 and away from the cargo space 78, the lip 142 not only does not infringe on the available storage space but its generally vertical downward orientation prevents the lip 142 from scratching or otherwise engaging the user's hands or arms or the material being stored in or removed from the container.
The [0053] lid 106 can be disposed on the upper rim 84 in a state of tension to effectively seal the cargo space 78. Accordingly, it is necessary that the upper rim 84 have enough strength such that it does not buckle inward under the tension of the lid 106 or under the weight of the contents of the container 70. The ribs 130 add enough strength to the upper rim 84 to protect against this occurrence.
Handles [0054]
The blow molded [0055] container 70 further includes ergonomic handles 80 as detailed in FIGS. 7, 9 and 10. Each handle is essentially a curved, hollow, open-ended tubular extension of the end panels 76 and has connection portions 144 extending outward from each end panel 76. Each handle 80 also has a hollow grip portion 146 disposed between the connection portions 144. The grip portion 146 includes an outside 148, a bottom side 150, a top side 152, an upper inside portion 154, and a lower inside portion 156.
[0056] Finger spaces 158 are defined by the distance between the end panels 76 and the grip portion 146 of the handles 80. The finger space 158 can preferably have a gap G between the end panel 76 and the grip portion 146 ranging from about 1.25 inches to about 1.50 inches. The length of the grip portions 146, can preferably be from about 3 to about 8 inches. The circumference of the grip portion 146 can preferably be from about 2 to about 4 inches. It has also been found that an ergonomically preferred handle 80 includes a grip portion 146 that has a width w that is slightly larger than its height h.
Further, it is preferred that the [0057] handles 80 not include any sharp corners or edges, such as flashing, which would otherwise cause pinch points. A smooth exterior surface to the grip portion 146 is preferred. Some consumers may prefer that the handles 80 not extend outward from the end panels 76 to a great extent as they could unnecessarily consume storage space. The above dimensions have been found preferable for ergonomic reasons. However, the dimensions can vary according to different consumers' tastes, for reasons such as size, style, and the like.
Mold [0058]
The [0059] storage container 70 described herein can be manufactured via blow molding with a molding apparatus 160, as shown in FIGS. 15-24. The mold 160 has a first half 162 and a second half 164. The first half 162 is depicted in FIG. 15. The second half 164, seen in a side view in FIG. 18 joined to the first half 162, is a mirror image of the first half 162. The two halves are joined together by butting the butt face 166 of the first half 162 against a corresponding butt face of the second half 164. The mold halves can be located by posts (not shown) extending from the first butt face 166 being inserted into locator holes in the second half 164, as is known. When referencing the mold 160 hereinafter, it will be understood that both mold halves are being described, unless otherwise mentioned.
The [0060] mold 160 includes a frame 170 to which is mounted a fixed section 172 and a moving section 174. The moving section 174 is movable up and down from a lowered position to a raised position during the molding process in an X direction by a cylinder 178 within guides 180, as will be described in detail later. As seen in FIG. 9, both the moving section 174 and the frame 170 may include wear plates 182 that bear on each other to decrease the friction and provide an inexpensive component that may easily be replaced instead of replacing the entire moving section 174 or frame 170.
The moving [0061] section 174 generally includes a tub section 184 and a pair of bottom inserts 186 mounted to the tub section 184. The tub section 184 includes a bottom face 188, a pair of end faces 190, and a side face 192 that provide a surface for which the resin 132 may be blown against to generally form the bottom panel 72, end panels 76, and side panels 74 of the storage container 70. The bottom face 188, the end faces 190, and the side face 192 can include relief holes (not shown) such that air inside the mold 160 can escape to the atmosphere, and further can function as a conduit for a vacuum such that a label can be held fast in the mold via vacuum pressure during the molding process to create an in-mold label or in a surface of the finished product.
Mold of End Rim [0062]
Referring to FIGS. 19 and 20, the following describes the elements of the moving [0063] section 174 and the fixed section 172 that can form the handle 80. Disposed at the top edge of the end faces 190 on the tub section 184 is an end lower face 194. The end lower face 194 provides a surface for the end lower section 90 of the end panel 76 and extends generally angularly outward away from the interior of the mold 160. The tub section 184 then extends laterally away from the center of the mold 160, providing a bottom insert receiver 196. Next to the bottom insert receiver 196 on the tub section 184 is a grip bottom face 198. The grip bottom face 198 is the surface that defines the grip bottom side 150 of the handle 80. Disposed next to the grip bottom face 198 is an end tub flash receiver 200. The end tub flash receiver 200 is adapted to receive and trap excess the excess resin 132 or flash 201 in the mold 160. The moving section 174 then extends downward to define a sliding portion 202.
The [0064] bottom insert 186 is mounted to the bottom insert receiver 196. The bottom insert 186 includes an inside face 204 that provides a surface for the first middle section 98 of the end rim 86 to be formed during the molding process. The bottom insert 186 also includes a cut plate 206 that aids in defining the finger space 158 in the handle 80, as will be detailed later. Finally, the bottom insert 186 includes an outside face 208 that provides a surface for the grip lower inside portion 156 of the handle to be formed.
Referring back to FIG. 15, the fixed [0065] section 172 is fixedly attached to the frame 160. The fixed section 172 includes a support section 210, a knife section 212, a handle insert 214, both attached to the support section 210, and an upper finger insert 216 mounted to the handle insert 214. Again referring to FIGS. 19 and 20, the support section 210 and the handle insert 214 define a sliding face 218 upon which the sliding portion 202 of the tub section 184 slides.
Disposed within the fixed [0066] section 172 is the handle insert 214. The handle insert 214 is adapted to form the grip outside 148 and the grip top side 152 of the handle 80, as well as the flat upper engagement surface 104 of the end upper section 96 of the end rim 86. The handle insert 214 includes an upper flash receiver 220, which is adapted to work with the end tub flash receiver 200 of the moving section 174 to contain any extra resin 132 within the mold 160. Next to the upper flash receiver 220 is the grip outside face 222, which transitions to the grip upper face 224. The grip outside face 222 and the grip upper face 224 provide surfaces to create the grip top side 152 and the grip outside 148.
Mounted to the [0067] handle insert 214 is the upper finger insert 216. The upper finger insert 216 includes a grip inside face 226 that corresponds to the grip upper inside section 154. On the bottom side of the upper finger insert 216 are first edge 228, a second edge 230, and a third edge 232. The three edges 228, 230, 232 interact with the cut plate 206 of the bottom insert 186 such that the finger spaces 158 are cut out, as will be detailed later.
The [0068] upper finger insert 216 also includes an inside face 234 which provides a surface for the resin 132 to be molded into the second section 100 of the end middle section 94. Finally, the upper finger insert 216 includes a protrusion 236 that forms the lid receiver 108 in the end middle section 94. Thus, the inside face 204 of the bottom insert 186 and the inside face 234 of the upper finger insert 216 combine to form the middle section 94 of the end rim 86.
The [0069] handle insert 214 also includes an upper face 238 that forms the upper section 96 of the end rim 86. Further attached to the support section 210 is the knife section 212. The knife section 212 includes a lip face 240 extending down and in to the mold 160, and a top edge 242. The lip face 240 forms the lip 102 of the end rim 86, and the top edge 242 creates a thin portion 244 of the resin 132.
Mold of Side Rim [0070]
With regard to FIGS. 17, 18, and [0071] 21-24, the forming of the side rim 88 by the moving section 174 and the fixed section 172 will now be described. Again, the moving section 174 includes a side face 192 that corresponds to the side panel 74 of the finished container 70. The side face 192 is connected to a lower face 246 that angles generally away from the cargo space 78 of the container 70. Extending upward from the lower face 246 is a ridge 248, best seen in FIG. 17. The ridge 248 includes a series of slots 250 extending downward. The ridge 248 and the slots 250 define the ribbed section 120 in the container 70, wherein the ridge 248 creates the arches 122, and the slots 250 create the downward extending ribs 130. Extending outward from the ridge 248 is a tub flash receiving surface 252, and extending downward from the tub flash receiving surface 252 is a sliding surface 254.
The sliding [0072] surface 254 of the tub section 184 slides against a sliding surface 256 of the support section 210. The support section 210 includes a support flash receiving area 258 which works in concert to trap the excess material or flash 260. The support section 210 includes a side middle face 262 and a side upper face 264 for forming the side middle section 134 and the side upper section 136, respectively. Again, disposed in the support section 210 is the knife section 212. The knife section 212 includes the lip face 266 and edge 268. Here again, the lip face 266 forms the downwardly extending lip 142, and the edge 268 creates a lesser cross-sectional area 270 of resin 132. Thus, the resin 132 can lay across the ridge 248, and can fill up the slots 250 to form the ribs 130.
Molding Process [0073]
The [0074] storage container 70 in the present example can be manufactured in the mold 160 by a blow molding process. A parison (not shown) can be extruded continuously. In one example, multiple layers of resin 132 are heated into a liquid, then are extruded into a mulit-layer parison. It is advantageous to use mulitple layers because it is possible to use cost-efficient re-ground plastic in one layer, such as a middle layer, which can then be hidden by an inside and an outside layer. Further, the inside layer can be a more expensive, more durable hard plastic, while the outside layer can be made from a more expensive softer plastic that may be more pleasing for consumers.
The parison can be made thicker at the top where the [0075] uppe rim 84 is to be formed by moving a mandrel within the extruder as is known. After the parison is extruded, the first mold half 164 and the second mold 166 half are brought together, trapping the parison in between. The moving sections 174 of the mold halves 164, 166 at this point are in the lowered position. An air source such as a blow pin (not shown) can then be placed into the mold through a first air inlet 272 and a second air inlet 274 in the fixed section 172 (seen in FIG. 15). In one example, the air source is placed into the first air inlet 272, while an air exhaust is placed in the second air inlet 274. In this manner, pressurized cool air can be continuously inserted into the mold, and exhausted, to ensure that only cool air is inside the mold 160 to increase the cooling rate of the resin 132 therein. If there was no air exhaust, the air inside the mold 160 would be warmed from the heat of the resin, and the cooling rate would be reduced. Further, by limiting the exhaust rate, the elevated pressure can be maintained in the mold 160.
The pressure from the air pushes the [0076] resin 132 of the parison outward against the surfaces of the mold 160. Since the moving section 174 is in the lowered position, areas of the sliding portions 218, 256 of the fixed section also receive part of the resin, as depicted in FIGS. 19, 21, and 23. These same figures depict the resin as it is being blown outward and prior to the resin 132 contacting the mold surfaces.
As the pressurized air enters the chamber, the [0077] resin 132 is blown against the mold surfaces. In FIG. 19, the resin 132 is forced against the end surface 190, the end lower face 194, bottom insert inside face 204, the sliding portion of the fixed section 218, the finger insert inside face 234. At this point, with the resin 132 still molten, the cylinder 178 is activated, and the moving section 174 is pushed upward in the X direction, as is shown in FIG. 20. The first, second, and third edges 228, 230, and 232 of the finger insert 216 contact the cut plate 206 of the bottom insert 186. A volume of flash 260 is captured between the first and second edges 228, 230 of the finger insert 216 and the bottom insert 186. A smaller volume of flash 260 is captured between the second and third edges 230, 232 of the finger insert 216 and the bottom insert 186. This smaller volume creates a rigid edge which makes it easier to cut out the flash 260 from within the finger space 158.
As the moving [0078] section 174 and the fixed section 172 come together, resin 132 is forced against the upper grip face 224, the outside grip face 222, the bottom grip face 198, and the bottom insert outside face 208, and the grip inside face 226. Further, extra resin 132 is caught in the end tub flash receiver 200. By including the end tub flash receiver 200, the resin 132 does not get stretched along the outside grip face 222 as the moving section 174 closes. Thus, unattractive stretch marks in the end product are avoided. A hollow handle 80 with a cut-out finger space 158 can thereby be created with the above blow molding technique.
The first [0079] middle section 98 is joined with the second middle section 100, and the resin 132 is forced against the upper section face 238 of the handle insert 214 by air pressure and by the closing moving section 172. The knife section 212 creates the lip 102, and the edge 242 creates a thin portion 244 of the cooled resin 132. The resin 132 is further forced upward into the knife section 212 to create a top piece 276. The thin portion 244 makes it easy to cut out the top piece 276 away from the storage container 70, to create an open top container 70 that can receive a lid 106 for sealing.
FIGS. [0080] 21-24 depict the portion of the mold 160 responsible for creating the side rim 88. The resin 132 is forced against the side face 192 of the tub section 184, the ridge 248 of the tub section 184, and through the slots 250 of the ridge 248. The resin 132 is further forced against the sliding portion 256, the middle face 262, and the upper face 264 of the support section 210. This can be seen in FIGS. 21 and 23. As the moving section 174 moves upward, as in FIGS. 22 and 24, a portion of the resin 132 becomes trapped in the support flash receiving area 258. The resin 132 then lays down over the ridge 248 to create the arch 122. The resin 132 further lays in the slots 250. The system may be designed such that the support flash receiving area 258 cannot fit all the available resin 132 therein. As such, the extra resin 132 is forced out of the support flash receiving area 258 and back into the mold 160 as the moving section 174 closes. This extra resin 132 then travels into the slots 250, thereby filling up the slots 250 and creating the downward extending ribs 130. The side upper section 136 and side lip 142 are created in the same manner as in the end upper section 96 and the end lip 102.
After the parison is fully inflated against the sides of the [0081] mold 160 and the storage container 70 has been formed, the top piece 276 and flashing 201, 260 remain. In a post-molding operation, this excess material can easily be cut away. The top section can include flat portions that can be used to hold the storage container 70 as the top portion 276 is cut away along the portions of reduced thickness 244, 270. The flashing 201, 260 is also cut away, and the resin can be re-ground and re-used in a later operation, or sold to recyclers.
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitation should be understood therefrom, as modifications within the scope of this disclosure may become apparent to those skilled in the art. [0082]

Claims

We claim:

1. A storage container comprising:

a bottom wall;

a pair of side walls extending up from the bottom wall;

a pair of end walls extending up from the bottom wall, the bottom wall, side walls, and end walls being interconnected and defining a cargo space;

a side rim disposed on top of the side walls and including a bottom portion extending outwardly from the side wall, an arch extending upward and downward from the bottom portion and defining a convex upper surface and a concave interior arch surface, a middle portion extending upwardly from the arch, an upper portion extending inward from the middle portion, and a lip extending downward from the upper portion, the lip being outside of the cargo space; and

a plurality of spaced apart ribs extending downward from and traversing the concave interior arch surface.

2. A method of manufacturing a storage container, the method comprising:

closing two mold halves about a parison, the mold halves including a fixed portion and an upwardly movable portion and defining a mold cavity;

applying air pressure to blow material against surfaces of the mold cavity; and

moving the movable portion upward during or immediately after the applying step to form at least one hollow handle grip and a side rim having an upward extending concave arch with a plurality of spaced apart ribs traversing the concave arch.