U.S. patent application number 10/444312 was filed with the patent office on 2004-02-12 for storage container with blow molded inverted rim and ergonomic handle.
Invention is credited to Marchetta, Tony, Rodi, Gina, Shepler, William, Skov, Erik.
Application Number | 20040026435 10/444312 |
Document ID | / |
Family ID | 29584453 |
Filed Date | 2004-02-12 |
United States Patent
Application |
20040026435 |
Kind Code |
A1 |
Skov, Erik ; et al. |
February 12, 2004 |
Storage container with blow molded inverted rim and ergonomic
handle
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.
Inventors: |
Skov, Erik; (Akron, OH)
; Shepler, William; (North Olmsted, OH) ; Rodi,
Gina; (Wooster, OH) ; Marchetta, Tony;
(Medina, OH) |
Correspondence
Address: |
MARSHALL, GERSTEIN & BORUN LLP
6300 SEARS TOWER
233 S. WACKER DRIVE
CHICAGO
IL
60606
US
|
Family ID: |
29584453 |
Appl. No.: |
10/444312 |
Filed: |
May 23, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60382749 |
May 23, 2002 |
|
|
|
Current U.S.
Class: |
220/600 |
Current CPC
Class: |
B29L 2031/463 20130101;
B29C 49/4823 20130101; B65D 1/46 20130101; B29L 2031/7126 20130101;
B65D 1/26 20130101; B65D 25/2888 20130101; B65D 21/0233 20130101;
B65D 1/22 20130101; B29C 49/4802 20130101; B29L 2031/712
20130101 |
Class at
Publication: |
220/600 |
International
Class: |
B65D 006/28; B65D
008/04; B65D 008/06 |
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.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application 60/382,749, filed May 23, 2002.
TECHNICAL FIELD
[0002] 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
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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 64a. Again, both rims 64, 64a terminate at inwardly extending
lips 66 which, although avoiding extending into the available
storage space, the lips 66 are sharp and therefore ergonomically
undesirable.
[0007] 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.
[0008] 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
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] In a refinement, the upper section of the rim is
substantially horizontal to provide an engagement or sealing
surface with a top or lid.
[0014] 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.
[0015] 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
[0016] The disclosed containers are described diagrammatically in
the following drawings wherein:
[0017] FIG. 1 is a partial sectional view of a reusable storage
container made by a conventional injection molding process;
[0018] FIG. 2 is an enlarged sectional view of the upper rim of the
container shown in FIG. 1;
[0019] FIG. 3 is a partial sectional view of a reusable storage
container made by a conventional blow molding process;
[0020] FIG. 4 is a partial sectional view of a reusable storage
container made by a conventional blow molding process;
[0021] FIG. 5 is another sectional view of the upper rim of the
container shown in FIG. 4;
[0022] FIG. 6 is an elevational view of a blow molded reusable
storage container made in accordance with this disclosure;
[0023] FIG. 7 is a top view of the storage container shown in FIG.
6;
[0024] FIG. 8 is an end view of the storage container shown in FIG.
6;
[0025] FIG. 9 is a fragmentary cross-sectional view of the handle
and upper rim of the storage container taken along line 9-9 in FIG.
8.
[0026] FIG. 10 is a perspective view of the handle section in FIG.
8, partially cut away.
[0027] 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 11-11 in FIG. 7.
[0028] FIG. 12 is a fragmentary cross-section view of the side rim
of the storage container taken along line 12-12 in FIG. 11.
[0029] FIG. 13 is a fragmentary cross-sectional view of the side
rim of the strorage container taken along line 13-13 in FIG.
11.
[0030] FIG. 14 is a fragmentary cross-sectional view of the side
rim of the storage container taken along line 14-14 in FIG. 12.
[0031] FIG. 14a is a perspective view of a portion of the side rim,
viewed from underneath and particularly showing the ribbing, of the
storage container.
[0032] 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.
[0033] FIG. 16 is a front elevational view of the apparatus of FIG.
15.
[0034] FIG. 17 is a front view of the moving section of the
apparatus.
[0035] FIG. 18 is a fragmentary cross-sectional view taken along
line 18-18 in FIG. 16, and showing the side rim forming
portion.
[0036] 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 19 in
FIG. 15.
[0037] 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 19 in FIG. 15.
[0038] 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 circle
21 in FIG. 16.
[0039] 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 circle 21 in FIG. 16.
[0040] 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 circle
21 in FIG. 16.
[0041] 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 circle 21 in FIG. 16.
[0042] 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.
DETAILED DESCRIPTION
[0043] General
[0044] A 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.
[0045] Rim
[0046] The tops of the respective two opposing 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.
[0047] Referring now to FIG. 9, each end rim 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.
[0048] The end rim 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.
[0049] The end rim 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.
[0050] Referring now to FIG. 11, the inside of a 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.
[0051] Connected to the side 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 14a) 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.
[0052] The ribbed 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.
[0053] The 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.
[0054] Handles
[0055] The blow molded 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.
[0057] Further, it is preferred that the 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.
[0058] Mold
[0059] The 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.
[0060] The 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.
[0061] The moving 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.
[0062] Mold of End Rim
[0063] Referring to FIGS. 19 and 20, the following describes the
elements of the moving 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.
[0064] The 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.
[0065] Referring back to FIG. 15, the fixed 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.
[0066] Disposed within the fixed 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.
[0067] Mounted to the 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.
[0068] The 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.
[0069] The 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.
[0070] Mold of Side Rim
[0071] With regard to FIGS. 17, 18, and 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.
[0072] The sliding 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.
[0073] Molding Process
[0074] The 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.
[0075] The parison can be made thicker at the top where the 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.
[0076] The pressure from the air pushes the 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.
[0077] As the pressurized air enters the chamber, the 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.
[0078] As the moving 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.
[0079] The first 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.
[0080] FIGS. 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.
[0081] After the parison is fully inflated against the sides of the
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.
[0082] 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.
* * * * *