U.S. patent application number 12/675107 was filed with the patent office on 2011-05-26 for composite lid for containers.
This patent application is currently assigned to BRASILATA S/A EMBALAGENS METALICAS. Invention is credited to Antonio Carlos Teixeira Alvares, Antonio Roberto Sene.
Application Number | 20110121009 12/675107 |
Document ID | / |
Family ID | 40336331 |
Filed Date | 2011-05-26 |
United States Patent
Application |
20110121009 |
Kind Code |
A1 |
Alvares; Antonio Carlos Teixeira ;
et al. |
May 26, 2011 |
COMPOSITE LID FOR CONTAINERS
Abstract
A composite lid for a container that includes a tubular body
carrying an annular upper wall made of sheet metal, in which is
defined an opening surrounded by a seat, which is configured to
receive and retain the lid. The lid includes a base portion
peripherally incorporating a retention portion to be seated and
retained on the seat when the lid is closed. The base portion
includes a peripheral annular element molded in a plastic material
as a single piece with the retention portion, and a central element
in the form of a sheet metal plate that has an outer peripheral
edge attached to the peripheral annular element. The peripheral
annular element includes, internally and in a single piece, a
central panel disposed on the central element, which is
incorporated to the lid during its injection or attached thereto
afterwards.
Inventors: |
Alvares; Antonio Carlos
Teixeira; (Sao Paulo-SP, BR) ; Sene; Antonio
Roberto; (Sao Paulo-SP, BR) |
Assignee: |
BRASILATA S/A EMBALAGENS
METALICAS
Sao Paulo-SP
BR
|
Family ID: |
40336331 |
Appl. No.: |
12/675107 |
Filed: |
September 1, 2008 |
PCT Filed: |
September 1, 2008 |
PCT NO: |
PCT/BR08/00267 |
371 Date: |
May 25, 2010 |
Current U.S.
Class: |
220/780 |
Current CPC
Class: |
B65D 2543/00509
20130101; B65D 2543/0024 20130101; B65D 2543/00435 20130101; B65D
2543/0087 20130101; B65D 2543/0074 20130101; B65D 43/021 20130101;
B65D 2543/00314 20130101; B65D 2543/00083 20130101 |
Class at
Publication: |
220/780 |
International
Class: |
B65D 43/02 20060101
B65D043/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2007 |
BR |
PI0703738-4 |
Jun 20, 2008 |
BR |
PI0802246-1 |
Claims
1. A composite lid for a container that comprises a tubular body
carrying an annular upper wall made of sheet metal, in which is
defined an opening surrounded by a seat, and which is configured to
receive and retain a lid, the composite lid comprising: a base
portion peripherally incorporating a retention portion to be seated
and retained in the seat, when the lid is closed, the base portion
including: a peripheral annular element molded in plastic material
in a single piece with the retention portion; and a central element
in the form of a sheet metal plate and having an outer peripheral
edge attached to the peripheral annular element.
2. The lid, as set forth in claim 1, in which the annular upper
wall of the container is formed in stamped sheet metal, to produce
a median scrap, wherein the central element of the base portion is
defined by said median scrap.
3. The lid, as set forth in claim 1 wherein the outer peripheral
edge of the central element is inserted and retained in the
interior of the plastic material of the peripheral annular
element.
4. The lid, as set forth in claim 3, wherein the peripheral annular
element includes, superiorly and in a single piece, an inner
peripheral wall portion projecting upwardly, in a substantially
cylindrical or frusto-conical arrangement, the inner peripheral
wall portion presenting an upper edge, that surrounds and retains
the outer peripheral edge of the central element.
5. The lid, as set forth in claim 4, wherein the upper edge of the
inner peripheral wall portion of the peripheral annular element
incorporates an inner annular flange that retains the outer
peripheral edge of the central element within an interior portion
of the inner annular flange.
6. The lid, as set forth in claim 3, wherein the sheet metal plate
of the central element is provided, along and slightly spaced from
its outer peripheral edge, with a plurality of spaced apart through
holes, configured to be filled with the plastic material of the
peripheral annular element, for retention of the central element by
the peripheral annular element.
7. The lid, as set forth in claim 6, wherein the through holes are
formed coaxially with deformed through holes of the sheet metal
plate of the central element projecting outwards from the plane of
the latter.
8. The lid, as set forth in claim 3, wherein the outer peripheral
edge of the central element is in the form of a curved curl.
9. The lid, as set forth in claim 3, herein the retention of the
outer peripheral edge of the central element in the interior
portion of the inner annular flange of the peripheral annular
element is hermetically provided.
10. The lid, as set forth in claim 3, wherein the peripheral
annular element incorporates, internally and in a single piece, a
closing central panel disposed on the central element.
11. The lid, as set forth in claim 1, wherein the peripheral
annular element incorporates, internally and in a single piece, a
closing central panel, the central element having its outer
peripheral edge fitted and locked in a retainer provided in the
peripheral annular element, in order to axially retain the central
element seated under said central panel.
12. The lid, as set forth in claim 11, wherein the peripheral
annular element includes, superiorly and in a single piece, an
inner peripheral wall portion that projects upwardly, in a
substantially cylindrical or frusto-conical arrangement, the inner
peripheral wall portion presenting an upper edge incorporating,
internally and in a single piece, the central panel, the retainer
being provided internally to the inner peripheral wall portion of
the peripheral annular element.
13. The lid, as set forth in claim 12, wherein the retainer
includes at least one radial projection incorporated, in a single
piece, in the inner peripheral wall portion and on which is fitted
the outer peripheral edge of the central element, when it is
mounted under the central panel.
14. The lid, as set forth in claim 12, wherein the retainer
includes at least one screw thread incorporated, in a single piece,
to the inner peripheral wall portion, and on which is fitted the
outer peripheral edge of the central element when it is mounted
under the central panel.
15. The lid, as set forth in claim 3, wherein the peripheral
annular element is incorporated, externally and in a single piece,
at a lower region of the retention portion, the retention portion
including a substantially cylindrical wall, circumferentially
incorporating an outer cradle to be seated against the seat, upon
closing the lid.
16. The lid, as set forth in claim 15, wherein the retention
portion of the lid incorporates, superiorly and in a single piece,
an annular wall projecting radially outwards, and configured to be
positioned over the annular upper wall of the tubular body, when
the lid is closed.
17. The lid, as set forth in claim 16, wherein the annular wall
includes an outer edge incorporating a gripping handle projecting
downwardly, said gripping handle being configured to remain in
proximity to the side wall of the body, upon the seating of the lid
on the seat.
18. The lid, as set forth in claim 16, wherein the annular wall
includes at least one circumferential rib extension projecting
upwardly at least one circumferential rib being configured as a
stacking guide.
19. The lid, as set forth in claim 2, wherein the outer peripheral
edge of the central element is inserted and retained in the
interior of the plastic material of the peripheral annular
element.
20. The lid, as set forth in claim 2, wherein the peripheral
annular element incorporates, internally and in a single piece, a
closing central panel, the central element having its outer
peripheral edge fitted and locked in a retainer provided in the
peripheral annular element, in order to axially retain the central
element seated under said central panel.
Description
FIELD OF THE INVENTION
[0001] The present invention refers to a lid formed of multiple
materials, more particularly in sheet metal and in plastic
material, to be applied to a container generally defined by a can
with a circular or polygonal cross-section, obtained in sheet metal
or in other materials, comprising a tubular body carrying an
annular upper wall, which defines an access opening to the interior
of the container and a seat on which the lid is removably fitted
and retained, for closing the container.
PRIOR ART
[0002] There are well known from the prior art the lids of cans or
other similar containers, said lids being constructed in a single
piece in stamped sheet metal or molded plastic material and
presenting a base portion, which covers the opening of the
container and peripherally incorporates a retention portion to be
seated and retained on the seat, when the lid is closed.
[0003] The lids formed in stamped sheet metal are generally
deprived of a tamper evident seal portion, which is incorporated to
the retention portion and radially projects outwards therefrom, to
cooperate with an upper edge region of the container body. These
lids in sheet metal have been used for many years and present
constructive variations in the base portion and in the retention
portion. However, although presenting substantial mechanical
strength and defining adequate impermeability to oxygen and water
vapor and also an adequate light barrier, these metallic lids lead
to the provision of tamper evident seal elements defined in
separate pieces applied to the container, externally or internally
positioned in relation to the lid, in order to comply with
determined applications.
[0004] On the other hand, the lids of the type considered herein
and molded in plastic material, can be formed in a single piece,
comprising base portion, retention portion and seal portion,
guaranteeing the obtention of a closure element, with adequate
characteristics of sealing, inviolability, strength and which is
easily opened and closed by the user of a product of progressive
consumption, which is stored in the container.
[0005] However, the plastic-molded lids can present some
limitations, in certain applications, regarding the gas and vapor
impermeability, particularly during long shelf periods, and also
the formation of an effective light barrier.
[0006] Another aspect to be considered concerns the containers,
whose annular upper wall is formed from a stamped sheet metal and
peripherally double-seamed or otherwise hermetically attached to an
end edge (upper edge) of the tubular body of the container. In
these conditions, the median scrap of sheet metal, resulting from
the stamping of the annular upper wall, is discarded as scrap, in
spite of representing a sheet metal portion generated in the
surface treatment required for application in the formation of
containers. None of the solutions of metallic lid or plastic lid
permit solving the problem of discarding the median scrap resulting
from the stamping of the annular upper wall of the container.
[0007] A known composite lid construction, made of plastic and
sheet metal, is described and claimed in the Certificate of
Addition C1 0401239-9. This previous document suggests a lid
construction comprising a base portion in sheet metal, with a
peripheral portion conformed to be seated on an upper edge of the
tubular body of the container and coupled to a retention ring, made
of plastic material, provided with seal means which guarantee the
axial retention of the lid in the closed condition.
[0008] The previous construction cited above, and those defined in
documents U.S. Pat. No. 5,881,907, U.S. Pat. No. 6,220,466, U.S.
Pat. No. 7,147,118 and U.S. Pat. No. 7,175,039, use a composite lid
comprising a base portion in sheet metal, integrally covering the
open upper end of the tubular body of the container and having a
peripheral portion necessarily conformed to be hermetically seated
on the upper edge of the tubular body, the axial retention of the
base portion being guaranteed by a peripheral annular element, in
plastic material, presenting an annular or blind upper flange
seated on the metallic base portion and a peripheral skirt to be
coupled to the retention means, externally provided in the tubular
body of the container and optionally incorporating a seal means
detachable upon the first opening of the lid.
[0009] However, the composite lid solutions commented above are
applied to containers without an annular upper wall for the
formation of the seat of the lid, the axial locking of the lid
being carried out by means, such as curl, rib or screw threads,
provided externally to the tubular body of the container and to be
engaged by the peripheral annular element in plastic material,
without having any sealing function in relation to the seat for
seating the base portion integrally in metal.
[0010] In these known composite lids, the oxygen and water vapor
impermeability and the light barrier are produced by the base
portion integrally in sheet metal, which is compulsorily conformed
to interact with the seat defined by the upper edge of the tubular
body of the container, either with or without help of an
intermediate resinous sealing material. These solutions present a
relatively complex and onerous construction, not being applicable
to lids to be fitted and retained on a seat defined on an annular
upper wall of the container.
SUMMARY OF THE INVENTION
[0011] As a function of the limitations and drawbacks of the prior
art composite lids, when related to the containers of the type
considered herein, it is an object of the present invention to
provide a lid in sheet metal and in plastic material, presenting an
improvement in the impermeability to oxygen (and other gases) and
light barrier, in relation to the lids formed only in plastic
material, through a simple construction which is less costly than
that of the known composite lids incorporating or not a tamper
evident seal.
[0012] It is yet a further object of the present invention to
provide a lid as mentioned above and which presents its metallic
portion formed by a stamping scrap.
[0013] It is also a further object of the invention to provide a
lid as defined above and which allows safely stacking the
containers closed by said lids.
[0014] In order to achieve the objects mentioned above, the lid in
question comprises a base portion which peripherally incorporates a
retention portion to be seated and retained on the seat of the
annular upper wall of the container, when the lid is closed.
[0015] In accordance with the invention, the base portion of the
lid comprises: a peripheral annular element molded in plastic
material, in a single piece with the retention portion; and a
central element in the form of a sheet metal plate and having an
outer peripheral edge hermetically attached to the peripheral
annular element.
[0016] By considering the formation of the annular upper wall in
stamped sheet metal, the present invention allows the central
element of the base portion of the lid to be defined by the own
median scrap resulting from the stamping of the annular upper wall,
whereby the metallic piece of the composite lid is then formed by
an element usually treated as scrap.
[0017] The lid formed according to the present invention has
practically its whole area, designed for closing the container
opening, defined by an opaque sheet metal plate being gas
impermeable and with an extremely less production cost, allowing
the retention portion in plastic material to operate as a sealing
element, in cooperation with the seat, and as an element for
axially retaining the lid to the tubular body of the container.
[0018] In a constructive variant, the peripheral annular element
can incorporate, internally and in a single piece, a closing
central panel, also in plastic material, disposed on the central
element. In this case, the plastic piece defined by the retention
portion, by the peripheral annular element and by the central
panel, establishes a hermetical closing barrier, which is
inferiorly reinforced in the region under the central panel with
the incorporation of the metallic central element which may have
its peripheral edge incorporated to the plastic material of the
peripheral annular element, during the injection of the plastic
material of the lid, or fitted to said plastic material after its
molding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will be described below, with reference to the
enclosed drawings, given by way of example of an embodiment of the
invention and in which:
[0020] FIG. 1 represents a perspective view of a construction for
the lid in question;
[0021] FIG. 1A represents a view similar to that of FIG. 1, but
illustrating a constructive variant of the lid, in which the
central element in sheet metal is totally covered with the plastic
material constitutive of the peripheral annular element and of the
retention portion;
[0022] FIG. 2 represents a partial diametral sectional view of the
lid of FIG. 1, when fitted on the seat formed on annular upper wall
of the tubular body of a can, said section taken according to line
II-II in FIG. 1;
[0023] FIG. 2A represents a partial diametral sectional view of the
lid, similar to that of FIG. 2, but considering the constructive
variant of FIG. 1A;
[0024] FIG. 3 represents a top perspective view of the central
element of the base portion of the composite lid;
[0025] FIG. 4 represents a partial diametral sectional view of the
central element of the lid, said section taken according to line
IV-IV in FIG. 3;
[0026] FIG. 5 represents a partial diametrical sectional view of
the lid, similar to that of FIGS. 2 and 2A, but considering another
constructive variant, according to which the central element is
attached to the peripheral annular element, after the molding of
the latter and by means of radial retaining projections
incorporated to the peripheral annular element;
[0027] FIG. 6 represents a partial diametrical sectional view of
the lid, similar to that of FIGS. 2, 2A and 5, but related to a
further constructive variant, according to which the central
element is attached to the peripheral annular element, after the
molding of the latter and through the screw thread incorporated to
the peripheral annular element;
[0028] FIG. 7 represents a top perspective view of the central
element illustrated in the embodiment of FIGS. 5 and 6; and
[0029] FIG. 8 represents a partially sectioned top perspective view
of a can provided with an annular upper wall, from which is
medianly obtained, by stamping, the central element of the base
portion of the lid, said central element being illustrated in an
exploded mode.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The composite lid of the present invention is applicable to
containers of the type which comprises a tubular body 10 in sheet
metal and having a usually cylindrical side wall 11, carrying an
annular upper wall 20, also in sheet metal, presenting an opening A
surrounded by a seat 21 against which is seated and retained a lid
30.
[0031] The annular upper wall 20 can be constructed in different
ways as, for example, being formed by a deformed portion of the
side wall 11 of the tubular body 10, as described in Brazilian
Patent Application PI 0504528-2 (PCT/BR2005/000232) of the same
applicant, or obtained in a separate sheet metal, being duly
stamped and peripherally attached to an upper edge of the side wall
11 of the tubular body 10, as illustrated in FIGS. 2 and 8, by an
upper double-seaming Rs.
[0032] Independently of the construction applied to the annular
upper wall 20 (either a single piece or a piece double-seamed to
the side wall 11 of the tubular body 10), it is constructed to
define, in its inner peripheral edge and around the opening A, a
seat 21 which, in the illustrated construction, takes the form of a
circular or substantially circular tubular cross-sectional rib,
obtained by bending the inner peripheral edge of the annular upper
wall 20 downward, upward and outward, until completing the tubular
form. However, it should be understood that the seat 21 may present
different constructions associable with the type of composite lid
proposed herein, guaranteeing not only the axial retention of the
latter on the seat 21, but also the tightness of the container. For
example, the seat 21 may have its cross-section defined by a circle
arc with an extension sufficient to guarantee the tight seating and
the retention of a confronting circumferential portion of the
lid.
[0033] As illustrated in FIG. 8, when the annular upper wall 20 is
formed in stamped sheet metal and double-seamed to the side wall 11
of the tubular body 10, the annular form of the upper wall is
obtained by stamping a median scrap R in the form of a flat
circular disk that would usually be discarded as scrap.
[0034] According to the invention, the lid 30 comprises a base
portion 31 which peripherally incorporates a retention portion 32,
molded in plastic material, to be seated and retained against the
seat 21.
[0035] The base portion 31 of the lid 30 comprises a peripheral
annular element 33, molded in plastic material, in a single piece
with the retention portion 32, and a central element 34 in the form
of a sheet metal plate and having an outer peripheral edge 34a to
be attached, hermetically or not, to the peripheral annular element
33. More specifically, the outer peripheral edge 34a of the central
element 34 is inserted and retained in the interior of the plastic
material constitutive of the peripheral annular element 33, in the
embodiment illustrated in FIGS. 1, 1A, 2 and 2A. In the embodiment
of FIGS. 1 and 2, the outer peripheral edge 34a of the central
element 34 must be hermetically retained in the interior of the
plastic material constitutive of the peripheral annular element 33,
since said central element 34 operates as part of the lid closure,
i.e., as a sealing element. In the embodiment of FIGS. 1A and 2A,
the peripheral annular element 33 incorporates, internally and in a
single piece, a closing central panel 33d disposed on the central
element 34. In this case, despite being more appropriate, the
retention of the outer peripheral edge 34a of the central element
34 in the plastic material of the peripheral annular element 33 is
not required to be necessarily hermetic.
[0036] When the annular upper wall 20 is attached to the container
by the upper double-seaming Rs, the central element 34 of the base
portion 31 of the lid is defined by the own median scrap R
resulting from the stamping of the annular upper wall 20, as
illustrated in FIG. 8. As is known, the median scrap R is produced
upon stamping the annular upper wall 20, before its double-seaming
to the side wall 11 of the tubular body 10.
[0037] In the illustrated construction, the peripheral annular
element 33, in plastic material, of the base portion 31, superiorly
incorporates, in a single piece, an inner peripheral wall portion
33a, projecting upwards, in a substantially cylindrical or
frusto-conical arrangement and having an upper edge 33b whose
plastic material surrounds and retains the outer peripheral edge
34a of the central element 34 in sheet metal, in the embodiments
illustrated in FIGS. 1, 1A, 2 and 2A. The peripheral annular
element 33 is also externally incorporated, in a single piece, to a
lower region of the retention portion 32 which, in the illustrated
construction, takes the form of a substantially cylindrical wall
32a, radially spaced from the inner peripheral wall portion 33a of
the peripheral annular element 33 of the base portion 31 and
circumferentially incorporating an outer cradle 35 to be seated
against the seat 21, in order to axially retain the lid 30 in the
closed condition. It should be understood that the peripheral
annular element 33 can be deprived of the inner peripheral wall
portion 33a, to receive and retain, in the interior of its
constitutive plastic material, the outer peripheral edge 34a of the
central element 34. In this case, the peripheral annular element 33
and the central element 34 are generally coplanarly arranged.
However, this coplanar construction does not present the advantages
of an adequate structural strength, gain of inner volume of the
container and a better stacking of the lids in the magazines of the
automatic closing machines.
[0038] Also according to the illustrated construction, the
retention portion 32 of the lid 30, more particularly its
substantially cylindrical wall 32a, superiorly incorporates, in a
single piece, an annular wall 36 which projects radially outwards,
to be positioned over the annular upper wall 20 of the tubular body
10, when the lid 30 is closed.
[0039] The annular wall 36 presents an outer edge 36a, which
extends over the upper double seaming Rs, or over the upper edge of
the side wall 11 of the tubular body 10 in case the upper double
seaming is not provided, said outer edge 36a incorporating a
gripping handle 37 projecting downwards, to remain close to the
side wall 11 of the tubular body 10 upon seating the lid 30 on the
seat 21.
[0040] In order to avoid lateral displacements between two
vertically stacked containers 10, the annular wall 36 can
incorporate at least one circumferential rib extension 36b, i.e.,
continuously formed or defined in segments, projecting upwards from
the annular wall 36, radially spaced back or not in relation to the
outer edge 36a of said annular wall 36, so as to be loosely and
telescopically fitted, inwardly or outwardly from the lower end
double seaming of another container 10, which is seated onto the
former in a stack, as illustrated in FIGS. 5 and 6, acting as a
stacking guide.
[0041] In order to guarantee a fixed and hermetical attachment of
the central element 34, in sheet metal, to the peripheral annular
element 33, in plastic material, in the embodiments of FIGS. 1, 1A,
2 and 2A, the sheet metal plate of the former is provided, along
and slightly spaced from its outer peripheral edge 34a, with a
plurality of spaced apart through holes 34b, which can be formed in
deformed through holes 34c of the sheet metal plate, projecting
outwards from the plane of the latter, said through holes 34b being
filled with the plastic material of the peripheral annular element
33, upon incorporation of the central element 34 to the peripheral
annular element 33. This incorporation may be carried out, for
example, by injection molding the peripheral annular element 33 and
the retention portion 32, in a single piece of plastic material, in
a mold in whose interior is previously positioned the central
element 34. The outer peripheral edge 34a of the central element 34
may also be in the form of a downwardly curved curl, for example,
so as to increase even more the mechanical retention between the
sheet metal and the plastic material. Aiming at easing the handling
and also structurally stiffening the central element 34, it may
also be provided with a central recess 34d in the form of a
downwardly projecting spherical cap.
[0042] In the illustrated constructions, the upper edge 33b of the
inner peripheral wall portion 33a of the peripheral annular element
33 incorporates an inner annular flange 33c, in whose interior is
retained the outer peripheral edge 34a of the central element 34.
However, different constructive arrangements are possible for
obtaining a secure and, if necessary, hermetical attachment of the
sheet metal of the central element 34 to the plastic material of
the single piece defined by the retention portion and by the
peripheral annular element 33.
[0043] A constructive variant of the lid 30 is illustrated in FIGS.
1A and 2A. In this construction, the peripheral annular element 33
is constructed so that the upper edge 33b of the inner peripheral
wall portion 33a, or its radially inner region, is extended, in a
single piece, over the whole extension of the central element 34,
forming a central panel 33d over the latter, in order to facilitate
printing the messages related to the identification of the product
to be packaged. In this embodiment, the degree of tightness in the
fixation region between the metallic central element 34 and the
peripheral annular element 33 is not required to be so high as that
required for the embodiment of FIGS. 1 and 2.
[0044] In the constructive variant illustrated in FIGS. 5, 6 and 7,
the peripheral annular element 33 incorporates, internally and in a
single piece, a closing central panel 33d, also in plastic
material, considering that, in this construction, the central
element 34 has its outer peripheral edge 34a fitted and locked in a
retention means 38 provided in the peripheral annular element 33,
so as to axially retain the central element 34 seated under said
central panel 33d which, in these embodiments, presents a
substantially constant thickness along the whole area defined
internally to the inner peripheral wall portion 33a.
[0045] In a particular way, when the peripheral annular element 33
superiorly incorporates, in a single piece, an inner peripheral
wall portion 33a provided with an upper edge 33b, as already
described for the previous embodiments, said upper edge 33b
internally incorporates, in a single piece, the central panel 33d,
the retention means 38 being provided internally to the inner
peripheral wall portion 33a of the peripheral annular element
33.
[0046] The retention means 38 can be defined, as illustrated in
FIG. 5, by a plurality of radial projections 38a or by a single
circumferential radial projection 38a incorporated, in a single
piece, to the inner peripheral wall portion 33a, and on which is
fitted the outer peripheral edge 34a of the central element 34,
when this is mounted under the central panel 33d.
[0047] The retention means 38 can be also defined, as illustrated
in FIG. 6, by at least one screw thread 38b incorporated, in a
single piece, to the inner peripheral wall portion 33a, and in
which is fitted the outer peripheral edge 34a of the central
element 34, in order to permit the latter to be axially retained to
the lid, seated against the central panel 33d.
[0048] In the embodiments of FIGS. 5 and 6, the upper edge 33b of
an inner peripheral wall portion 33a directly incorporates the
central panel 33d, without the provision of the inner annular
flange 33c of the embodiments illustrated in FIGS. 1, 1A, 2 and 2A.
In the constructions of FIGS. 5 and 6, the circumferential radial
projection 38a, in one piece or in a plurality of radially
projecting elements angularly spaced apart, is slightly spaced from
the central panel 33d, in order to define therewith a gap in which
is tightly fitted a corresponding circumferential extension of the
outer peripheral edge 34a of the central element 34, allowing the
latter to be safely and easily attached and seated under the
central panel 33d of the lid 30, after the injection of the plastic
material of the latter, permitting simplifying the molding
tools.
[0049] While only some embodiments of the invention have been
illustrated herein, it should be understood that alterations can be
made in the form and physical arrangement of the different
components of the lid, without departing from the constructive
concept defined in the claims accompanying the present
specification.
* * * * *