U.S. patent number RE28,797 [Application Number 05/600,413] was granted by the patent office on 1976-05-04 for lid.
This patent grant is currently assigned to Solo Cup Company. Invention is credited to Clarence T. Brewer.
United States Patent |
RE28,797 |
Brewer |
May 4, 1976 |
**Please see images for:
( Certificate of Correction ) ** |
Lid
Abstract
A coverall lid or closure for gripping and sealing engagement
with the bead of a cuplike container. The lid includes a central
panel which is connected to a circumferential cavity by means of a
corrugated ring. The cavity is adapted to receive the bead of the
container and abut the bead in sealed engagement. A conical skirt
extends downward and outward from the lower edge of the cavity. The
upper portion of the skirt and the lower portion of the cavity form
a waist and this waist is interrupted by a series of
circumferentially spaced flutes. The portion of the skirt between
the flutes act as lands, each land having a decreasing
circumferential extent from a lower portion to an inner portion
thereof to facilitate flexing of the lands radially outward when
engaged by the container bead. The lower portion of the cavity is
moveable into position beneath the bead to grip the latter when the
lid is fitted on the container.
Inventors: |
Brewer; Clarence T. (Oak Park,
IL) |
Assignee: |
Solo Cup Company (Urbana,
IL)
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Family
ID: |
27083598 |
Appl.
No.: |
05/600,413 |
Filed: |
July 30, 1975 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
843671 |
Jul 22, 1969 |
03583596 |
Jun 8, 1971 |
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Current U.S.
Class: |
220/781; 206/508;
220/784 |
Current CPC
Class: |
B65D
43/0212 (20130101); B65D 2543/00027 (20130101); B65D
2543/00092 (20130101); B65D 2543/00296 (20130101); B65D
2543/00509 (20130101); B65D 2543/00537 (20130101); B65D
2543/00555 (20130101); B65D 2543/00638 (20130101); B65D
2543/00685 (20130101); B65D 2543/00731 (20130101); B65D
2543/00796 (20130101) |
Current International
Class: |
B65D
43/02 (20060101); B65D 041/16 (); B65D
041/18 () |
Field of
Search: |
;220/306,355,374
;229/43,1.5B ;150/.5 ;206/508 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hall; George T.
Attorney, Agent or Firm: Fitch, Even, Tabin &
Luedeka
Claims
What I claim is:
1. A lid for gripping and sealing engagement with a container
having a bead about an upper edge thereof, said lid comprising a
central panel, means defining an inwardly opening,
circumferentially extending cavity on said lid at a position
radially outwardly of said central panel to receive said bead and
to abut said bead in sealed engagement, means connecting said
cavity to the outer edge of said panel, a conical skirt extending
downward and outward from the lower edge of said cavity defining
means and terminating a free end having a diameter larger than the
diameter of said bead, whereby the upper portion of said skirt and
the lower portion of said cavity defining means from a waist, and a
series of circumferentially spaced flutes, interrupting said waist,
the portions of said skirt between said flutes acting as lands when
the lid is telescoped on a container, each of said lands having a
decreasing circumferential extent from a lower portion to an inner
portion thereof to facilitate flexing of said land radially outward
when cammed by the container bead, the lower portion of said cavity
defining means being moveable into position beneath said bead to
grip the latter when the lid is fitted on said container.
2. A lid in accordance with claim 1 in which said cavity-defining
means is elongated in the vertical direction to accommodate bulges
in the container bead.
3. A lid in accordance with claim 1 in which said connecting means
includes a flexible annular corrugated ring disposed between said
central panel and said cavity-defining means, each of the
corrugations in said ring being tapered on height with the higher
ends outermost.
4. A lid in accordance with claim 3 in which said flutes project
upwardly into said cavity-defining means to a point immediately
below a tangential line to said cavity-defining means.
5. A lid in accordance with claim 4 in which the waist extends
inward to about one-half of the width of said cavity and the skirt
extends downward at an angle of less than about 31.degree. to the
vertical plane.
6. A lid in accordance with claim 1 in which stacking lugs in the
shape of oblique frustums of triangular pyramids depend from said
central panel and into the area defined by said skirt for resting
on another central panel of another lid when stacked therewith,
said lugs having one corner thereof directed outward.
7. A lid in accordance with claim 5 in which said connecting means
includes a tapered collar connecting the inner end of the
corrugations to the central panel.
8. A lid for gripping and sealing engagement with an open mouth
container having an annular bead about the upper edge thereof, said
lid comprising a central panel extending substantially across the
mouth of the container, a conical-shaped collar joined to outer
edge of said panel, a ring having radially extending corrugations
joined to and projecting outward and downward from said collar,
said corrugations being tapered in height with the higher ends
being outermost, a circumferentially extending cavity defining
means joined to said ring and elongated in the vertical direction
to receive said container bead and to have a sealed engagement
therewith, a conical skirt depending from said cavity defining
means and projecting downwardly and outwardly to a free end having
a diameter larger than that of said container bead, whereby the
lower portion of said cavity-defining means and the upper portion
of said skirt forms a waist and a series of flutes interrupting
said waist, the portions of said skirt between said flutes acting
as lands when the lid is telescoped on the container, each of said
lands having a decreasing circumferential dimension in the upward
direction and flexing outward about the lower and wider portion of
said land to permit telescoping of said lid on said container bead,
said lower portion of said cavity-defining means flexing inward and
beneath said bead when said lid is telescoped on said container to
grip therewith and hold said lid in sealed engagement with said
container bead.
9. A lid in accordance with claim 8 in which stacking lugs in the
shape of oblique frustums of triangular pyramids depend from said
central panel into the area defined by said skirt for resting on
another central panel of another lid when stacked therewith, said
lugs having one corner thereof directed outward.
10. A lid in accordance with claim 8 in which the waist extends
inward about one-half the radial width of said cavity. .Iadd. 11. A
lid for gripping and sealing engagement with a container having a
bead about an upper edge thereof, said lid comprising a central
panel, means defining a circumferentially extending cavity on said
lid at a position radially outwardly of said central panel to
receive said bead and to abut said bead in sealed engagement, means
connecting an inner end of said cavity defining means to the outer
edge of said panel for permitting said inner end to flex and to
expand the cavity radially outwardly during application to a
container bead, a conical skirt extending downwardly and outwardly
from a lower edge of said cavity defining means and terminating in
a free end having a diameter larger than the diameter of said bead,
an upper portion of said skirt and the lower edge of said cavity
defining means forming a waist having a diameter less than the
outer diameter of the container bead, a series of circumferentially
spaced flutes interrupting said waist, said flutes having a
decreasing depth from said waist toward said free end of said
conical skirt, and surfaces of decreasing circumferential extent in
the upward direction on portions of said skirt between said flutes
acting as lands for camming engagement with the container bead when
the lid is forced onto a container, said means being being located
downwardly of said connecting means and radially inwardly of the
outermost portion of said cavity thereby defining an inwardly
directed access opening into said cavity for the bead, said waist
being positioned to engage the bead and to be forced radially
outwardly during movement of said bead through said access opening,
the outward movement of said waist forcing an upper wall of said
cavity defining means to roll outwardly which forces said
connecting means upwardly, and said waist returning to a position
beneath said bead to grip the latter and the radially outer end of
said connecting means positioned adjacent the bead when said bead
is
projected into said cavity. .Iaddend..Iadd. 12. A lid in accordance
with claim 11 in which said flutes have an increasing width in said
conical skirt from their lower ends to said waist. .Iaddend..Iadd.
13. A lid in accordance with claim 12 in which said connecting
means includes a flexible annular corrugated ring disposed between
said central panel and said cavity defining means. .Iaddend..Iadd.
14. A lid in accordance with claim 11 in which said lands are
generally flat and generally trapezoidal in shape. .Iaddend..Iadd.
15. A lid in accordance with claim 11 in which said waist extends
inward to about one-half the width of said cavity and the skirt
extends downward at an angle of less than about 31.degree. to the
vertical plane. .Iaddend..Iadd. 16. A lid for gripping and sealing
engagement with a container having a bead about an upper edge
thereof, said lid comprising a central panel, a cavity defining
wall extending circumferentially on said lid at a position radially
outwardly of said central panel to receive said bead therein, a
conical skirt extending downward and outward from the lower edge of
said cavity defining means and terminating in a free end having a
diameter larger than the diameter of said bead, said conical skirt
joining a lower and radially outwardly end of said cavity defining
wall at a waist located substantially beneath the center of said
cavity to grip the underside of a bead inserted therein, a radially
inner end of said cavity wall being spaced upwardly and radially
inwardly of said waist, a connecting wall extending
circumferentially between said central panel and said inner end of
said cavity defining wall, said connecting wall extending upwardly
and inwardly from said inner end of said cavity to the outer edge
of said central panel, said inner and outer ends of said cavity
wall defining an access opening directed inwardly and a series of
circumferentially spaced flutes interrupting said waist, and the
portions of said skirt between said flutes acting as lands as said
bead forces said waist outwardly and rolls the upper wall portion
of said cavity defining wall in an upward and outward direction as
said bead is being forced through said access opening and into said
cavity, the radially outer end of said connecting means being
disposed adjacent said bead when said lid is positioned on said
container, said lands having a decreasing circumferential extent in
an upward direction and said flutes having a decreasing depth from
said waist toward said free end of said conical skirt.
.Iaddend..Iadd. 17. A lid in accordance with claim 16 formed of one
piece and thermoformed from a sheet of plastic of uniform
cross-sectional thickness. .Iaddend..Iadd. 18. A lid in accordance
with claim 17 in which spaced stacking lugs are formed in said
central panel for resting on the central panel of another lid when
stacked therewith. .Iaddend..Iadd. 19. A lid in accordance with
claim 16 in which said connecting means comprises a flexible
annular corrugated ring disposed between said central panel and
said cavity defining means. .Iaddend.
Description
This invention relates to lids for cuplike containers and more
particularly to lids of the single end use, disposable type for
cuplike containers having a curled top edge or bead.
Cuplike containers, having their top edges curled outwardly,
downwardly and back under to form curled rims or beads, are
commonly used to package foods, both solid and liquid, especially
for carryout and end-point serving. Such containers are generally
of the tapered or conical nesting type. The containers may be
manufactured from sheet paper, treated or saturated with wax or a
combination of wax and plastic, or from sheet paper laminated to
thin plastic which serves as the interior of the container.
Alternately, the cuplike containers may be post-treated with a
coating, or a saturated coating, of wax or of a combination of wax
and plastic. Containers of the above-described type may also be
manufactured from sheet plastic by the thermovacuum-pressure
forming process. In both the paper and plastic manufacturing
processes, it is common practice to form the body of the container
in one operation and the head in another operation, with both
operations being automatically and progressively performed in one
machine.
Variations in material characteristics, in sheet thickness and in
manufacturing tools and processes cause dimensional tolerances in
the container mouth diameter and the size or thickness of the bead
that are difficult to economically control below a certain minimum.
There are roundness irregularities in the circumference of the
container and there are also variations in the uniformity of the
bead size around the top edge of the container. Also, the bead is
not exactly round; it is normally either round or egg-shaped with
the top edge having the smaller curvature. The bead in containers
made of sheet paper has a slightly enlarged portion resulting from
the side seam of such containers.
The lid for such a container, in order to fit snugly on the
container and be reasonably leaktight, should compensate for these
nonuniformities or irregularities in the bead and container mouth
and the variations between containers. Of course, the lid should be
easy to apply to, or remove from the container. Other desirable
features which should be provided in the lid are: (1) The lid
should have sufficient retention on the container so that when two
or more full containers with attached lids are placed in a bag or
package in juxtaposition with the edge of the lid of one container
overhanging one or more other lids, the weight of that one
container does not peel or rake off the lid; (2) When the container
with the attached lid is held or lifted by gripping opposite sides
of the skirt of the lid with the thumb and fingers, the retention
of the lid on the container should be increased; (3) The skirt of
the lid should be of sufficient length to provide sanitary
protection for the lip area when lifting or holding the container
with the attached lid in the above-described manner; ( 4) For ease
of manufacture, the lid should be of such a design that it is easy
to form by a thermovacuum-pressure forming process and is easy to
strip from the mold.
Stacking of the lid is another important consideration,
particularly where the lids are picked up, conveyed or transported
to packaging for shipment or where the lids are dispensed to end
use. The lids should nest freely, one with the other, and should
nest uniformly laterally so as to form a very rigid column that can
be compressively picked up or conveyed by the ends of the stack.
The lids should maintain this uniform stack in a shipping carton
and be capable of separation from nesting without resistance for
dispensing to end use.
An object of the present invention is to provide a lid which
incorporates one or more of the above desirable features.
Other objects and advantages of the invention will become apparent
from the detailed description taken in connection with the
accompanying drawings in which:
FIG. 1 is a perspective view of a container having an attached lid
embodying the features of the invention;
FIG. 2 is a top view of the lid of FIG. 1;
FIG. 3 is an enlarged fragmentary, cross-sectional view of a lid on
a container;
FIG. 4 is an enlarged fragmentary, cross-sectional view of several
lids in a stack; and
FIG. 5 is an enlarged fragmentary view of flutes and lands on the
lid.
As shown in the drawings, a lid 11 is provided having a
circumferentially extending cavity 12 (as best seen in FIG. 3) for
releasable sealing engagement with a bead 13 of a cuplike container
15 which may be either made by vacuum forming sheet plastic or made
from sheet paper, as previously described. The lid 11 is formed
with a central disclike panel 17 adapted to extend substantially
across the open mount 19 of the container when the lid is
telescoped on the container. The lid also includes a conical lid
skirt 21 which extends downward from the lower edge of the cavity
12. The lower portion of the cavity 12 and the upper portion of the
skirt 21 form a waist and this waist is interrupted by a series of
circumferentially spaced flutes 22. In telescoping the lid 11 on
the container 15, the portions 23 of the skirt between the flutes
22 act as lands 23 which are cammed laterally outward by the bead
13 of the container thereby expanding the waist to permit it to
pass over the container bead 13. A corrugated ring 25 is disposed
between the cavity 12 and the central panel 17, for a purpose
described hereinafter. The lid 11 is provided with stacking lugs 27
projecting downwardly from the central panel to rest on the top of
the central panel of a lid immediately beneath it, as best seen in
FIG. 4.
Referring now in greater detail to the embodiment shwon in the
drawings, the lid 11 is preferably designed so that it is easily
manufactured from a plastic sheet by a thermovacuum-pressure
forming process and is easily stripped from its mold. For purposes
of description, the lid 11 is described as it would be viewed from
the container or its underside. The lid 11 includes the conical
skirt 21 which, as illustrated, flares generally downward and
outward from the lower portion of the cavity 12 to a maximum
diameter at its lower free edge. Along the lower edge of the skirt
21 is an outward extending and substantially horizontal flange 29
which may be employed as a surface to be pushed for detaching the
lid 11 from the container 15. This flange, which is necessary for
presently available trimming operations, should be as narrow as
possible to minimize the possibility of the lid being raked off by
adjacent containers, as previously described.
When the lid 11 is initially placed on the container, it is
normally skewed with one side of the bead 13 seated fully in the
cavity 12. The inner diameter of the lower free edge of the skirt
21 is made of sufficient diameter to cover the maximum tolerance
outside diameter of the container bead 13 when the lid 11 is in the
skewed position on the container. The skirt 21 is made of
sufficient length to provide a low-pressure angle as the skirt
slides over the bead 13. When the lid 11 is attached to the
container 15, the skirt 21 provides sanitary protection for the lip
area about the container mouth.
The upper portion of the skirt 21 and the lower portion of the
cavity 12 form a waist. The waist is interrupted by a series of
circumferentially spaced-apart flutes 22. The illustrated flutes 22
are radius grooves which is the preferred shape but, in certain
applications, they also may be narrow slots. These flutes 22
provide telescopic rigidity to the skirt 21 and the lower portion
of the cavity 12, thereby avoiding an inward bellows action when
the lid is applied to the container.
The relatively flat portions 23 of the skirt 21 between the flutes
act as lands, which are cammed outwardly by the bead 13, when the
lid is pressed downwardly on the container 15, without digging in
or marring the bead. To this end the lands 23 have sufficient
conical strength structurally to cause the flutes to expand
circumferentially or diametrically, that is, the width of the lands
23 vary between the lower and upper portions thereof. Each land 23
has a wider circumferentially extending lower portion 37 (FIG. 4)
at the lower free end of the skirt 21 than at an upper or innermost
portion 39.
The lands 23 are connected to lower rounded portions 43 of the
rim-receiving cavity 12. The lower rounded portions 43 of the
cavity 12 form hooks or latches that snap over the bead 13 and
apply a slight tightening down camming action to hold the lid
against inadvertent separation from the container 15. The lower
rounded portions 43 extend inward approximately to one-half the
width of the cavity 12. For the purpose of facilitating the camming
and snapping action of the hooks 43 on the container bead 13, the
lower rounded portions 43 are formed with a downwardly curved
surface disposed at an angle of about 43.degree. to the horizontal
as exemplified by the angle A in FIG. 4. With a smaller angle it
would be difficult to remove the lid from the mold.
The waist is expanded by the narrower upper portions 39 of the
lands 23 being cammed laterally outwardly. This camming action
causes the walls forming the adjacent flutes 22 to be distorted and
the rounded portions 43 to roll outward. The increased intermediate
widths of the flutes 22 and the nonparallelism of the land-defining
walls also aid in the flexing to accommodate the bead 13. The
camming action is facilitated by providing the land 23 at a small
angle relative to the vertical (angle B in FIG. 3) preferably at an
angle not greater than about 31.degree..
The pivoting of the land 23 and the outward rolling of the rounded
portions 43 to expand the waist are further enhanced by having the
tops of the flutes 22 joined to the rim-receiving cavity 12 as
close as possible to a point of tangency with the inner surface of
the cavity 12, as best seen in FIG. 3. If the tops of the flutes 22
were made tangential to the cavity 12, the flutes 22 would extend
further upwardly to the center of the cavity 12 and thereby provide
passageways between the rim and cavity wall through which liquid
might leak. The preferred angle for the point of connection of the
flutes 22 to the cavity 12 is at an angle of about
15.degree.-20.degree. from a horizontal plane, as illustrated by
the angle C in FIG. 3.
As previously explained, beads 13 are formed by a rolling of the
material which results in noncircular cross sections and sometimes
results in flats, bulges or other variable cross-sectional
dimensions in the beads. In seamed containers, the double thickness
of the material at the seam causes an enlargement or bulge. It has
been found that containers may have a tolerance in the height of
the bead of 0.025 inches. To seal with beads 13 having such
variations, the cavity 12 is formed with a vertical dimension,
i.e., a height, to receive the maximum tolerance dimension of a
container bead. Additionally, an upper rounded wall 45 (FIG. 3) of
the cavity 12 is blended into a flat vertically disposed outer wall
49 with the result that the cavity 12 is elongated in the vertical
direction. The inner diameter of the vertical wall 49 is selected
to be slightly less than the minimum tolerance diameter of the bead
13 or that of the minimum tolerance diameter of the bead with
interference. The flatness of the cavity 12 provided by the
vertical wall permits the cavity to bulge where needed.
The upper arcuate wall 45 is joined at its inner end with an
upwardly facing curved surface 53 at the lower edge of the
corrugated ring 25. The corrugated ring 25 extends inward and
upward from its lower edge and includes a plurality of corrugations
57 each of which has a substantially uniform circumferential extent
and decreases in height. The sides of the corrugations 57 are
radially disposed, the corrugations thereby being wider at the
outer ends than the inner ends.
The corrugated ring allows the upper wall 45 of the cavity to roll
upwardly and outwardly to accommodate variations in the bead
diameter. Also, the upwardly curved surface 53 readily deforms in a
localized area as the corrugated ring 25 spreads circumferentially
and flexes upwardly whereby the lid may fully seat and grip despite
bulges or other such enlargements. The corrugated ring 25 also
allows the lid to be easily removed from the container without any
abrupt or jarring action by placing two or more fingers on top of
the lid, near the edge of the panel 17, and the thumb under the
lower edge of the skirt 21 and gently squeezing between the thumb
and fingers simultaneously with a prying action.
The corrugated ring 25 is connected to the center panel 17 by means
of a conical-shaped collar or tapered cylinder 55. The angle
between the face of the center panel 17 and the collar (angle D in
FIG. 3) is made greater than 90.degree. and the angle between the
collar 55 and the upper surface of the corrugated ring 25 (angle E
in FIG. 3) is made approximately 90.degree. so that the lid does
not permanently buckle. Alternately, the angles may be interchanged
(i.e., angle D may be made 90.degree. and angle E may be made
greater than 90.degree.. Also, this collar 55 facilitates the
rolling of the cavity 12.
The preferred manner of stacking is by means of three spaced
stacking lugs 27, each in the shape of an oblique frustum of a
triangular pyramid with the edges of faces flattened or rounded.
The lugs are integrally formed in and project downwardly from the
top panel 17 to a position in horizontal plane beneath the plane of
lower portions 43 of the cavity 21. More particularly, the bottom
walls 61 on the stacking lugs 27 abut the central panel 17 of a lid
immediately below to space the skirt 21 from engaging and prevent
its moving into a wedging engagement with the outer surface of the
lid cavity 12. As illustrated in FIG. 2, the stacking lugs are each
positioned so that one corner 67 thereof is directed outwardly so
that, when the plastic material from which the lid is thermoformed
shrinks upon cooling, the lid is easily stripped from the mold.
The preferred equipment for forming a series of lids simultaneously
from a sheet of plastic has the stacking lugs angularly spaced at
different angles in the various lid forming dies so that the lids
when formed have the stacking lugs in a series of nonmatchable
positions. Thus, each group of lids formed from a single sheet may
be stacked immediately without having the bottom walls 61 of one
lid aligned and projecting into the openings of the stacking lugs
in the lid next below.
From the foregoing, it will be seen that the lid may be
manufactured by thermoforming or pressured formed from a sheet of
plastic and provided with sufficient flexibility at the depending
skirt to fit containers having bead diameters which vary
substantially over a relatively wide range of tolerances. The lids
are particularly suited for accommodating bulges at the seams or
other nonuniform cross sections in roller beads. The lids may be
readily stacked yet are prevented from wedging into engagement with
one another which would prevent the easy release of one lid from
another.
While a preferred embodiment has been shown and described, it will
be understood that there is no intent to limit the invention by
such disclosure but, rather, it is intended to cover all
modifications and alternate constructions falling within the spirit
and scope of the invention as defined in the appended claims.
* * * * *