U.S. patent application number 11/118139 was filed with the patent office on 2006-11-02 for molded paint can with knit-free handle.
Invention is credited to Terry L. Kline, Michael S. Tunison.
Application Number | 20060243733 11/118139 |
Document ID | / |
Family ID | 37233460 |
Filed Date | 2006-11-02 |
United States Patent
Application |
20060243733 |
Kind Code |
A1 |
Kline; Terry L. ; et
al. |
November 2, 2006 |
Molded paint can with knit-free handle
Abstract
A paint can has a molded plastic bucket and cover which are
releasably engageable with one another at a seal. The bucket has an
integrally-formed, knit-free handle. The anchors for the handle are
knit to the side wall or reinforcing ring of the bucket.
Inventors: |
Kline; Terry L.; (Wheaton,
IL) ; Tunison; Michael S.; (Buffalo Grove,
IL) |
Correspondence
Address: |
COOK, ALEX, MCFARRON, MANZO, CUMMINGS & MEHLER LTD
SUITE 2850
200 WEST ADAMS STREET
CHICAGO
IL
60606
US
|
Family ID: |
37233460 |
Appl. No.: |
11/118139 |
Filed: |
April 29, 2005 |
Current U.S.
Class: |
220/771 |
Current CPC
Class: |
B65D 25/325 20130101;
B44D 3/12 20130101 |
Class at
Publication: |
220/771 |
International
Class: |
B65D 25/10 20060101
B65D025/10 |
Claims
1. A molded bucket, comprising a floor, a wall attached to the
floor and extending therefrom to an upper end, a pair of handle
anchors connected to the upper end of the bucket wall, and a knit
free handle extending from the handle anchors, the handle anchors
being connected to the upper end of the wall at knit zones which
are remote from the handle.
2. The molded bucket of claim 1 wherein the upper end of the wall
further comprises a reinforcing ring extending at least partially
around the wall with the handle anchors being attached to the
reinforcing ring.
3. A bucket having a floor, a wall having an upper end, and an
arcuate handle attached at two anchors to the upper end of the
wall, the bucket being formed by the process of: forming handle,
anchor, floor and wall cavities in a mold with the handle and wall
cavities being in fluid communication with the anchor cavities and
the floor and wall cavities being in fluid communication with one
another; feeding molten material into the mold cavity for the
handle; feeding molten material into one of the mold cavities for
the floor and wall; controlling the feeding of molten material such
that the anchor cavities are filled from the handle cavity;
solidifying the molten material in the mold cavities; and releasing
the finished bucket from the mold cavities.
4. A method of making a bucket having a floor, a wall having an
upper end, and an arcuate handle attached at two anchors to the
wall, the method comprising the steps of: forming handle, anchor,
floor and wall cavities in a mold with the handle and wall cavities
being in fluid communication with the anchor cavities and the floor
and wall cavities being in fluid communication with one another;
feeding molten material into the mold cavity for the handle;
feeding molten material into one of the mold cavities for the floor
and wall; controlling the feeding of molten material such that the
anchor cavities are filled from the handle cavity; solidifying the
molten material in the mold cavities; and releasing the finished
bucket from the mold cavities.
5. The method of claim 4 wherein the controlling step is further
characterized by feeding the molten material such that material fed
into the handle cavity extends at least partially from the anchor
cavities into the wall cavity.
6. The method of claim 4 wherein the forming step is further
characterized by forming the wall cavity to include a reinforcing
ring cavity near the upper end.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to containers for liquids and is
particularly concerned with a container intended for use with paint
and similar materials. It will be understood that the invention is
directed to the structure of a container, and is not limited to use
with any particular contents. Obviously the purpose of a paint can
is to contain paint in a condition that prevents unintended release
or removal of the liquid from the bucket, while allowing convenient
access to the liquid when desired. A paint can requires a rugged,
reliable, sealing engagement between the top of the bucket and the
cover. Simultaneously, access to the can's contents requires the
cover to release its engagement with the bucket upon reasonable,
directed effort on the part of the user. These somewhat
contradictory requirements have more or less been resolved in
satisfactory fashion over the years for traditional metal paint
cans. Recently, however, for reasons of cost and convenience, paint
cans integrally molded from plastic materials have become
competitive with the metal paint can.
[0002] Paint cans have traditionally been provided with a carrying
handle and plastic paint cans are no exception. Metal cans usually
had a handle in the form of a wire bail. The bail was a separate
piece that was pivotally attached to the bucket. The ends of the
bail were received in receptacles attached to the bucket to form a
hinge. It is preferable in plastic cans not to have the handle
formed as a separate part, due to the extra manufacturing step of
attaching such a handle to the bucket and due to the problems of
assuring that a separate handle remains connected to the bucket.
Thus, the handle is integrally formed in plastic paint cans.
However, this has also proven to have its share of problems in
prior molded paint cans. Such buckets have a generally
semi-circular handle fastened to opposite sides of the bucket near
the top edge of the bucket at attachment anchors. Living hinges are
formed at the junctions of the handle and anchors. The molding
process used in prior art cans formed the handle by feeding molten
plastic material into a mold cavity from the bucket floor, into the
walls, through the two attachment anchors and into the handle
cavity from both ends. The plastic material feeding into the handle
cavity from the two anchor areas would meet some-where in the
arcuate extent of the handle cavity, typically somewhere near the
middle. These two separate bodies of plastic material feeding into
the handle cavity would then have to blend together or knit to form
the complete handle. While this can be accomplished under carefully
controlled molding conditions and with properly selected grades of
materials, doing so can increase the cost of the paint can due to
the need for more expensive molding equipment, slower cycle times
and increased material costs. More importantly, it has been found
that molding the handle by attempting to knit two bodies of plastic
fed from separate directions can lead to handle failures when
optimum conditions and materials are not utilized. When such handle
failures occur, particularly with an open bucket at a work site,
the results are not favorable for either the painter or the paint
supplier. Particular unpleasantries are reserved for the paint can
manufacturer when the knit handle fails. The present invention
resolves these issues by providing an improved molded paint
can.
SUMMARY OF THE INVENTION
[0003] The present invention concerns a paint can that can be
molded of plastic material. A primary object of the invention is a
paint can having a knit-free handle attached to the bucket by
knitting the handle anchors to the walls of the bucket.
[0004] The paint can has a bucket and cover which are releasably
engageable with one another. The cover has sealing elements that
cooperate with the upper edge of the bucket. Inner and outer
sealing walls on the cover receive the top land of the bucket. The
bucket is molded by feeding molten plastic material into a mold
cavity both from two separate gates in the mold. The two gates feed
into mold cavities for the floor of the bucket and from the center
of the handle. The fed materials meet somewhere in the side walls
of the bucket so the two streams knit together at a point remote
from the handle itself. This forms a knit free handle and places
the knit locations at a point where the loads on the container will
be spread out over the greatest area.
[0005] These and other desired benefits of the invention, including
combinations of features thereof, will become apparent from the
following description. It will be understood, however, that a
device could still appropriate the claimed invention without
accomplishing each and every one of these desired benefits,
including those gleaned from the following description. The
appended claims, not these desired benefits, define the subject
matter of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a side elevation view of the bucket of the present
invention.
[0007] FIG. 2 is a top plan view of the bucket of FIG. 1.
[0008] FIG. 3 is a bottom plan view of the bucket.
[0009] FIG. 4 is a section taken along line 4-4 of FIG. 2.
[0010] FIG. 5 is an enlargement of the upper left corner of FIG. 4,
illustrating the details of the top edge of the bucket.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The paint can of the present invention includes a bucket and
a cover or lid. The bucket 10 will be described in conjunction with
FIGS. 1-5. The bucket 10 includes a circular floor 12. The center
of the floor panel may have a dimple or indentation 14. The dimple
provides an advantageous location for one of the gates in a mold
that feeds plastic material for forming the bucket. The molding
process is an important feature of the present invention and will
be discussed in greater detail below. On the underside of the floor
12 there is a circular foot 16. The foot is engageable with a cover
of a second paint can to facilitate stacking of multiple cans.
[0012] The bucket further includes a cylindrical wall 18 that
extends upwardly from the outer edge of the floor 12 to an upper,
open end. The wall joins the floor at a junction 19. The wall 18
has an inner face 20 and an outer face 22. At the upper end on the
inner face there is a very slight indentation formed by a mold
parting line 24 (FIGS. 4 and 5). The upper end portion of the wall
terminates at a top land 26. The top land joins the inner and outer
faces 20, 22 at corners 28 and 30 (FIG. 5). The corners have a
simple radius. Corner 28 defines a circular opening into the
interior of the bucket. At the upper end of the wall 18, on the
outer face 22, there is a radially extending projection 32. This
projection encircles the top of the bucket. It meshes with a catch
on the cover to retain the cover on the bucket. The upper end of
the wall 18 also includes a reinforcing ring 34 just beneath the
projection 32 on the outer surface 22 of the wall 18. The ring is
formed by a radial extension 36 and an axial flange 38 attached to
the extension. Arcuate ribs or gussets 40 (FIG. 3) are formed
underneath the radial extension and inside the axial flange to
further stiffen the ring 34.
[0013] A pair of handle anchors 42, 44 are attached to the upper
end of the bucket wall. In a preferred embodiment the anchors are
formed on the outer edge of the reinforcing ring 34, as seen in
FIGS. 2 and 3. Alternately, the anchors could be attached directly
to the outer surface 22 of the upper end of the wall. The anchors
mount a handle 46. It will be understood that the handle is shown
in the as-molded condition where it is in a generally horizontal
plane. In use the handle will be pivoted about the anchors to a
substantially vertical plane with most of the bucket hanging below
the handle. FIG. 2 shows that the handle is a generally
semi-circular bail which includes two outer portions 48 and a
central portion 50. FIG. 1 shows that central portion 50 has a
lower edge 54 that widens the handle in the central portion. Finger
indentations or grooves 52 are provided on the underside of the
central portion. The central portion provides a cushioned grip that
reduces the tendency of the handle to dig into a user's hand or
fingers when carrying a full paint can. The finger grooves 52
further enhance the comfort of the handle.
[0014] The construction of the handle and in particular the central
portion 50 is noteworthy. As best seen in FIG. 1 the central and
outer portions 48, 50 have coplanar upper surfaces. However, the
lower surface 54 of the central portion extends downwardly below
the lower surfaces of the outer portions 48. It will be understood
that the references to "upper" and "lower" surfaces of the handle
are with respect to the horizontal, as molded condition of the
handle, as shown in FIG. 1, before the handle is pivoted to a
vertical plane for use. Two frangible tabs 55 connect the handle
outer portions 48 to the reinforcing ring 34. The tabs are small
enough to be readily broken when the handle is lifted to a vertical
position for use. With the construction shown the cross sectional
area of the central portion 50 is greater than that of the outer
portions 48. The handle 46 is formed in a manner that leaves it
free of molding knit zones, as will be described below.
[0015] A suitable cover (not shown) will be provided to close the
open end of the bucket. The cover forms no part of the present
invention.
[0016] A variety of plastic materials may be suitable for the
bucket. A preferred material for the bucket is a polypropylene
copolymer. However, it will be understood that substitutions for
this material could be made without departing from the scope of the
present invention.
[0017] The process for molding the bucket is as follows. A mold is
prepared that has cavities for forming the floor, the wall
including its upper end portion, the handle anchors and the handle.
The cavities are in fluid communication with one another so the
entire bucket is molded at the same time. Specifically, the handle
cavity communicates with the anchor cavities which in turn
communicate with the cavity for the upper end portion of the wall,
including the reinforcing ring. The wall cavity communicates with
the floor cavity. For these purposes the foot may be considered
part of the floor. The mold cavities are filled from two gates, one
located at the floor dimple 14 and one formed at or near the
central portion of the handle. Molten plastic material is fed from
both of these gates. The feeding process is controlled so that
while the majority of the material is fed through the floor gate,
all of the material forming the handle and handle anchors is fed
through the handle gate. Thus, the handle material enters the
handle gate and flows in two directions from the gate through the
handle cavity, into the handle anchor cavities and tabs and from
there into the reinforcing ring portion of the wall cavity. Floor
fed material joins or knits with the handle fed material in the
wall cavity, in the vicinity of the handle anchors but spaced from
the handle anchors. Accordingly, no knitting of material occurs in
the handle cavity. The handle is free of knitted areas or zones.
There are knit zones in the walls. However, the knitting that
occurs in the walls is in areas of lesser stress concentration than
the handle and thus there is a reduced chance of failure than if
there were a knit zone in the handle. This molding process greatly
reduces the chances of handle failures while also reducing cycle
times by decreasing the amount of time it takes to fill the
mold.
[0018] While the preferred form of the invention has been shown and
described herein, it should be realized that there may be many
modifications, substitutions and alterations thereto. For example,
while the anchors are shown attached to the reinforcing ring, they
could be attached directly to the wall of the bucket. That is, the
reinforcing ring may be located spaced from the anchors. Or in
certain circumstances it may be possible to delete the reinforcing
ring altogether. Thus, the knitting of molten plastic material may
take place in the reinforcing ring, if there is one, or it may take
place in the bucket wall, whether the reinforcing ring is present
or not. What is important is that the knitting does not take place
in the handle cavity. Also, while the bucket wall is shown as
completely cylindrical, it need not have this exact shape. It could
have a conical portion or it could include hand grips formed in the
sides.
* * * * *