U.S. patent application number 15/919654 was filed with the patent office on 2019-09-19 for gasketless closure for open-top pails.
The applicant listed for this patent is Letica Corporation. Invention is credited to Arthur Habitz, Christopher Myles Larsen, Anton Letica, John R. Selina.
Application Number | 20190283937 15/919654 |
Document ID | / |
Family ID | 67905122 |
Filed Date | 2019-09-19 |
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United States Patent
Application |
20190283937 |
Kind Code |
A1 |
Selina; John R. ; et
al. |
September 19, 2019 |
Gasketless Closure For Open-Top Pails
Abstract
A molded plastic closure is configured to provide a plug fit
with the top rim of an open top container having an outwardly
protruding rim flange. A two-part seal preventing leakage of fluid
from the container is provided by means of a ridge structure on the
inner wall of the inverted U-shaped channel of the closure
peripheral structure as well as a flexible sealing wiper appendage
which is formed integrally with the top of the inverted U-shaped
structure and which deformingly contacts the top surface of the
container rim when the rim is essentially fully inserted into the
U-shaped channel. The wiper appendage is formed to angle toward the
inner channel wall in the undeflected condition.
Inventors: |
Selina; John R.; (Brighton,
MI) ; Larsen; Christopher Myles; (Farmington Hills,
MI) ; Letica; Anton; (Bloomfield Hills, MI) ;
Habitz; Arthur; (Berkley, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Letica Corporation |
Rochester Hills |
MI |
US |
|
|
Family ID: |
67905122 |
Appl. No.: |
15/919654 |
Filed: |
March 13, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65D 2543/005 20130101;
B65D 43/0258 20130101; B65D 2543/00296 20130101; B65D 2543/00555
20130101; B65D 2543/00953 20130101; B65D 2543/00796 20130101; B65D
2543/00657 20130101; B65D 2543/00685 20130101; B65D 43/0208
20130101; B65D 2543/0074 20130101; B65D 2543/00092 20130101; B65D
2543/00509 20130101; B65D 2543/0099 20130101; B65D 2543/00537
20130101 |
International
Class: |
B65D 43/02 20060101
B65D043/02 |
Claims
1. A closure for a pail having a sidewall ending in an outwardly
protruding top rim having a substantially flat top surface and a
substantially flat undersurface wherein said closure comprises: a
molded plastic body having a center deck and an integral annular
peripheral channel portion with radially spaced apart inner and
outer annular walls defining an inverted annular U-shaped channel
having an interior inner top and outer surfaces for lockingly
receiving said top rim and a portion of said sidewall therein; said
outer wall having an annular ledge to lockingly abut the under
surface of said outwardly protruding annular rim when the pail rim
is inserted into said annular channel; said interior inner surface
having annular sealed ridges formed thereon to lie sealingly
against an inner sidewall surface of said pail to form a first
seal; and a sealing wiper appendage integrally depending from the
interior top wall of said inverted U-shaped channel and angled
downwardly and inwardly toward said interior inner surface so as to
deformingly contact the top surface of said outwardly protruding
rim when said rim is inserted into said channel to form a second
seal with said container.
2. A closure as defined in claim 1 wherein the entirety of the
closure is molded from high density polyethylene (HDPE).
3. A closure as defined in claim 1 wherein the sealing wiper
appendage has a root and a length and wherein the ratio of the
length dimension to the root dimension is approximately 4.25:1.
4. A closure as defined in claim 3 wherein the length of the
appendage is about 0.170''.
5. A closure as defined in claim 1 wherein the wiper appendage
angles inwardly toward said inner wall by about 20.degree..
Description
FIELD OF THE INVENTION
[0001] This invention relates to closures; i.e., "lids," for
open-top pails and, more particularly, to a plug fit closure that
provides an effective seal between the closure and the pail without
the use of a conventional gasket.
BACKGROUND
[0002] Molded plastic closures for open-top pails are in wide
spread use and are available from numerous manufacturers including
the Letica Corporation of Rochester, Mich. The pails, also called
"containers," and closures are generally made from high density
polyethylene, hereinafter "HDPE," and are injection molded in a
range of capacities from about one to six gallons and may or may
not have pouring spouts and bails for carrying. The closures snap
or "lock" firmly on the pails and may have various means such as
tear bands on an outer skirt to aid in removal from the pail.
[0003] Where such pails are used to carry perishable goods or
fluids, it is common to design the closure to provide a "plug fit"
wherein the pail rim extends into and is trapped between the
parallel walls of an inverted U-shaped annular channel formed in
the peripheral portion of the closure structure. Conventional
wisdom further calls for the use of a resilient gasket which is
placed in the top of the channel and against which the top of the
inserted pail rim bears to form a seal. An example of such a
pail/closure combination is shown in U.S. Pat. No. 7,207,457 issued
Apr. 24, 2007 to Stefan Schwarz and assigned to Letica
Corporation.
[0004] The gasket itself adds to the cost of the product and the
placement of the gasket into the channel is a secondary operation
that adds still more cost and complexity to the manufacturing
process. This presents a competitive disadvantage; moreover,
recycling of the closure becomes more complex because of the
different materials used to make the closure and the gasket.
[0005] As a result, various attempts dating back to at least 1976
have been made to eliminate the gasket while still providing an
effective seal. One approach is to manufacture both the closure and
the pail to close tolerances to provide a very tight fit and to
design the mold to provide a complex and a conforming geometry
between the pail rim and the closure. Again, this puts pressure on
the design, manufacture, and maintenance of the tooling used to
injection mold the HDPE lid and pail. Further, the seals can lose
effectiveness due to age and/or damage to the pail rim or the
closure channel through ordinary handling.
SUMMARY OF THE INVENTION
[0006] The invention here described follows conventional wisdom
insofar as it utilizes a plug fit between the top rim of an
open-top container provided by an inverted U-shape channel formed
in the peripheral structure of the closure, but departs from the
prior art in the manner in which a seal is provided.
[0007] The closure design contemplates use in combination with a
pail or container having a sidewall ending at the top in an
outwardly protruding rim having a top surface. The rim cooperates
with a ledge on an interior wall of the closure to "lock" the
closure on the container. The closure itself comprises a molded
plastic body having a center deck and an integral peripheral
channel portion with radially spaced apart inner and outer annular
walls for receiving the top rim of the pail therein. The outer wall
or "skirt" may have a tear strip on the lower end to facilitate the
first removal of the closure from the pail.
[0008] The pail/closure embodiment used herein to explain the
invention is generally cylindrical, albeit tapered. As a result,
the pail rim and the peripheral channel of the closure are annular.
However, the invention is not limited to cylindrical pails and can
be used to advantage in oval, square, and rectangular pails.
[0009] The outer interior wall of the channel in the disclosed
embodiment is formed with an annular ledge or "undercut" to
lockingly receive and cooperate with the outwardly protruding
annular pail rim when the pail rim is sufficiently inserted into
the annular channel. The interior of the channel, particularly the
surface of the inner wall, has a continuous annular rib
configuration that provides a first primary seal in cooperation
with the inner surface of the pail. In addition, the closure is
molded to provide a sealing wiper appendage which is integral with
the closure and depends downwardly and inwardly from the interior
top wall of the channel; i.e., the appendage leans or curves toward
the inner wall interior surface. When the seal wiper is deformingly
contacted by the top surface of the pail rim upon insertion of the
pail rim into the channel, the appendage bends further toward the
inner wall to form a second seal.
[0010] The closure is preferably, but not necessarily, injection
molded from HDPE. In addition, the sealing wiper appendage
preferably has a ratio of length to root dimension of approximately
4.25:1 in a closure for a five-gallon pail, one of the most popular
sizes, and has a 5.degree. taper from root to distal end. As
indicated above, and in accordance with prior practice, the
container may be made in any of the commercially popular sizes and
shapes, may be tapered or straight-walled, and the closure is
designed and manufactured to correspond to the top configuration of
the container.
[0011] As a result of the design of the closure herein described
and the cooperation between the closure and the pail, a firm and
reliable gasketless seal that can withstand rough handling without
leakage is accomplished in a cost-efficient fashion. By virtue of
the seal, air is prevented from entering container during storage
to spoil or otherwise adversely affect perishable content, and
leakage of fluids from the container in the event of tip overs,
drops, and other handling events is substantially prevented.
BRIEF DESCRIPTION OF THE DRAWING
[0012] FIG. 1 is an example of a molded plastic closure and pail
combination of the type to which the invention can be practically
applied;
[0013] FIG. 2 is a sectional view of a portion of the closure
showing features of the invention;
[0014] FIG. 3 is a dimensioned detail of the closure channel;
[0015] FIG. 4 is a dimensional detail of the wiper appendage;
[0016] FIG. 5 is a perspective view of a portion of the closure
channel; and
[0017] FIG. 6 shows the closure channel with the pail rim inserted
and locked in place.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT
[0018] Referring to FIG. 1 there is shown a molded plastic closure
10 for a five-gallon open-top molded plastic pail 12 having a
tapered sidewall 14 and a wire bail 16. Both the closure 10 and the
pail 12 are preferably injection molded from HDPE. Other plastics,
such as polypropylene, can also be used.
[0019] The closure 10 has an annular peripheral portion 18
surrounding a generally circular inner deck portion 20 and is sized
to fit on the pail 12 in such a way as to "lock" onto the pail and
provide a seal to prevent both the ingestion of air into the pail
12 as well as to prevent leakage from any fluid carried by the pail
in the fully closed condition. This representation is intended to
be generic in nature; i.e., it shows a typical pail/closure
configuration wherein the closure has a "plug fit" on the pail rim,
and also has a "tear strip" on the outer skirt, details of which
are omitted here but can be found in the Schwarz patent identified
above, incorporated herein by reference.
[0020] Referring now to FIGS. 2-6, details of the annular
peripheral portion 18 of the closure 10 are described. As stated
above, the pail 12 has a slightly tapering sidewall 14 which ends
in an annular top rim portion 15 with a generally a flat-top
although the edges, both inner and outer, may be radiused. The top
rim portion 15 is shown in FIG. 6 to have a rolled-over
configuration but can also be flat-bottomed. The rolled-over
configuration is preferred. The diameter of the rim 15 is about
11.5 inches.
[0021] The annular peripheral portion 18 of the closure 10 consists
of an outer wall or "skirt" 26 and an inner wall 32 which, together
with the top wall 36, define an inverted U-shaped channel into
which the top rim portion of the pail 12 is inserted as best shown
in FIG. 6 to provide a plug fit. This means that, in addition to an
outer wall that captures only the outside of the pail rim, the
closure has an inner wall that extends down into the container.
[0022] The inside surface of the outer wall or skirt portion 26 of
the closure 10 is molded with an annular groove 28 which weakens
the material to allow the lower portion 30 of the skirt to function
as a "tear strip" in conventional fashion. Details of a tear strip
structure can be found in the above-described Schwarz patent,
incorporated herein by reference. A ledge 38 is formed below the
top wall 36 of the inverted U-shape channel to lockingly interact
with the undersurface of the top rim 15 of the pail 12 as shown in
FIG. 6.
[0023] The inside surface of the inner wall 32 is molded to provide
two vertically spaced continuous, annular seal ridges 40 that
contact the inside surface of the container sidewall when
sufficiently inserted into the U-shaped channel to provide a
primary seal. See FIG. 6.
[0024] An inner structure 34 connects the inverted U-shaped channel
to the center deck 20 in the manner shown to provide for stacking
stability if desired.
[0025] The inner surface of the top wall 36 of the peripheral
structure 18 has molded thereon a single circularly continuous
sealing wiper 42 which depends downwardly and inwardly; i.e.,
toward the inner wall 32. The angle of the wiper appendage 42 is
about 20.degree. but this angle is not deemed critical so long as
the appendage curves or angles inwardly toward the inner wall 34
and not outwardly toward the skirt wall 26. A practical lower limit
would be about 15.degree..
[0026] The appendage 42 is thicker at the base or root; i.e., where
it integrally joins the top wall 36, than it is at the distal end
as shown in FIG. 4. The appendage 42 also has a length of about
0.170'' which is less than the distance between the inside surface
of the top wall 36 and the ledge 38. The distance between the
inside surface of the top wall 36 and the ledge 38 is also slightly
greater than the distance between the top surface and the
undersurface of the pail rim 15 so as to provide the slight
clearance shown in FIG. 6. The ratio of the root thickness to the
length of the appendage 42 is approximately 4.25:1. The overall
length of the appendage 42 will depend on the size of the closure
but is approximately 0.170'' for a closure that fits a standard
five-gallon molded HDPE container with an 11.5'' diameter.
[0027] FIG. 6 shows the pail sidewall 14 with the top rim portion
15 essentially fully inserted into the U-shaped channel between the
walls 26 and 32; i.e., inserted sufficiently far to seat the
undersurface of the pail rim onto the top surface of the ledge 38
on the interior of the closure skirt portion 26, thereby
essentially locking the closure 10 on to the pail rim 12. In this
condition the inside surface pail sidewall fully contacts the ribs
40 to provide a primary seal therebetween. Furthermore, the top
surface of the rim 15 deflects the sealing wiper appendage 42
inwardly, creating more annular surface area of contact with the
surface of the rim 14 thus providing an additional seal.
[0028] In use, the pail and closure are shipped to the retailer
unattached. The retailer fills the pail and firmly attaches the
closure to the pail to complete the seal. Filled pails can be
stacked to a degree depending on the design strength of the pail
and closure, and the weight of the pail contents. The end user
opens the pail by removing the tear strip. The closure can be
reapplied to preserve unused content as needed.
[0029] It is to be understood that while the invention has been
described in this document with respect to a specific but
illustrative embodiment, various configurational and size changes
may be made within the scope of the invention described and claimed
herein. The drawings, although not fully dimensioned, are to
scale.
* * * * *