U.S. patent number 3,856,184 [Application Number 05/285,000] was granted by the patent office on 1974-12-24 for easy-opening container closure having a sliding tab.
This patent grant is currently assigned to Crown Cork & Seal Company, Inc.. Invention is credited to John J. Luviano.
United States Patent |
3,856,184 |
Luviano |
December 24, 1974 |
EASY-OPENING CONTAINER CLOSURE HAVING A SLIDING TAB
Abstract
A can end of the easy opening type includes an end panel having
a dispensing aperture and a partially preformed vent hole. An easy
opening tab including a portion adapted to slide between closed and
opened positions over the dispensing aperture includes a flip-over
finger engageable portion which is double-backed over the sliding
portion when the tab is in the closed position. A closure panel
puncturing projection extends from the flip-over portion of the tab
so as to engage the partially pre-formed vent hole when the
flip-over portion is pivoted to a substantially upright position.
The continued pivoting of the flip-over tab to a flattened position
on the end panel opposite the dispensing aperture and the
interaction of the puncturing projection of the vent hole opening,
slides the sliding portion of the tab to a position opening the
dispensing aperture.
Inventors: |
Luviano; John J. (Rydal,
PA) |
Assignee: |
Crown Cork & Seal Company,
Inc. (Philadelphia, PA)
|
Family
ID: |
23092323 |
Appl.
No.: |
05/285,000 |
Filed: |
August 30, 1972 |
Current U.S.
Class: |
222/80;
222/541.9 |
Current CPC
Class: |
B65D
17/506 (20130101) |
Current International
Class: |
B65D
17/00 (20060101); B65D 17/50 (20060101); B65d
047/10 () |
Field of
Search: |
;222/541,80,85,484
;220/47,43,41,44,46 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tollberg; Stanley H.
Attorney, Agent or Firm: Woodcock, Washburn, Kurtz &
Mackiewicz
Claims
What is claimed is:
1. A closure of the easy opening type comprising:
a closure panel having a dispensing aperture therein and an at
least partially pre-formed vent hole spaced therefrom;
an easy opening tab including a sliding portion closing said
dispensing aperture, a flip-over portion having a hinged connection
with said sliding portion, and a vent hole puncturing portion
extending from said flip-over portion, said flip-over portion being
double-backed over said sliding portion when said tab is in the
closed position with said vent hole puncturing portion extending
away from said closure panel, said vent hole puncturing portion
contacting said partially pre-formed vent hole when said flip-over
portion is pivoted about said hinged connection to a position
extending outwardly away from said sliding portion, said flip-over
portion forming a lever having a fulcrum at said hinged connection,
the overall length of the lever arm of said flip-over portion being
longer than the distance from the point of contact between said
partially pre-formed vent hole and said hinged connection so as to
provide a substantial mechanical advantage in puncturing said end
panel at said partially pre-formed vent hole.
2. The closure of claim 1 wherein said vent hole puncturing portion
cooperates with said panel adjacent said vent hole after puncturing
so as to slide said sliding portion to open said dispensing
aperture as said flip-over portion is moved toward said vent
hole.
3. The closure of claim 2 wherein said vent hole puncturing portion
pushes against an edge of said vent hole as said flip-over portion
moves toward said vent hole thereby inducing a sliding motion of
said sliding portion.
4. The closure of claim 3 wherein said vent hole puncturing portion
is substantially arcuate in cross-section in a plane parallel to
said hinged connection.
5. The closure of claim 4 wherein a substantial portion of said
edge of said vent hole is substantially arcuate.
6. The closure of claim 1 wherein said panel and said tab comprise
steel.
7. The closure of claim 1 further comprising a plastic sealant
forming a seal between said tab and said closure at said dispensing
aperture before opening.
8. The closure of claim 1 wherein said end panel is lanced in a
partially closed configuration so as to form said partially
pre-formed vent hole and said closure further includes a plastic
sealant material for forming a seal between lanced edges of said
panel at said vent hole before said puncturing.
9. The closure of claim 1 wherein said vent hole is spaced from
said dispensing aperture and said hinge connection is located
between said dispensing aperture and said vent hole.
10. The closure of claim 2 wherein said dispensing aperture is
formed by a double-folded layer of said closure panel extending
over said tab with a raw edge of said closure panel extending
beneath said tab on opposing sides of said opposing aperture so as
to form a sliding track for said tab, said closure further
comprising a plastic sealant material forming a seal between said
raw edge of said panel and the sliding tab.
11. The closure of claim 2 wherein the edge of said dispensing
aperture is formed by a portion of the raw edge of said closure
panel extending over said tab and another portion extending beneath
said tab along opposing sides of said dispensing aperture, said
closure further comprising a plastic sealant for forming a seal
between said tab and said closure panel at said dispensing
aperture.
12. The closure of claim 2 wherein said sliding portion is recessed
adjacent said the edge of said flip-over portion to permit
insertion of the end of a finger under said flip-over portion.
13. The closure of claim 2 wherein said closure panel is domed
upwardly toward said puncturing portion of said tab before
opening.
14. A closure of the easy-opening type comprising:
an end panel to be attached to a container body, said end panel
having a dispensing aperture therein and an at least partially
pre-formed vent hole spaced from said dispensing aperture; and
an easy opening tab including a sliding portion in communication
with the contents of the container body when said sliding portion
closes said dispensing aperture and a finger engageable lever
portion connected with said sliding portion, said lever portion
including vent hole opening means adapted to initially open said
vent hole as said lever portion is pivoted about the connection
with said sliding portion so as to release pressure on the sliding
portion, said lever portion subsequently cooperating with said
panel adjacent said vent hole for sliding said sliding portion to
an open position as said lever portion is further pivoted about
said connection.
15. The closure of claim 14 wherein said vent hole opening means
engages said panel at an edge of said vent hole as said lever
portion is further pivoted about said connection thereby sliding
said sliding portion to said open position.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to easy opening containers including easy
opening cans having finger engageable tabs for use in opening
cans.
The most commercially successful easy opening can of the tab-type
has utilized a tab which is formed by scoring a can end panel and
removed by grasping a ring attached thereto with the resulting
ripping of the tab from the end panel along the score lines.
Aluminum is usually utilized for ring-tab ends of this type because
of its soft and malleable qualities which allow the use of
substantial residual scoring depths while still permitting removal
of the tabs by hand.
However, aluminum can ends of this type do present a number of
problems. First, aluminum is expensive and, due to its low strength
relative to steel, large quantities of aluminum must be utilized in
providing can ends of sufficient gauge to withstand the internal
pressures generated within the cans. Since aluminum is also
expensive relative to steel, the conventional can comprises a steel
can body with only the end or ends comprising aluminum. This in
itself is undesirable since an electrochemical reaction may be set
up within a can due to its metalic nature thereby creating the risk
that the contents within a container may become contaminated.
Aluminum can ends of the ring-tab type are also undesirable from an
ecological standpoint. Aluminum, unlike steel, is not readily
degradable. Furthermore, the removable nature of the aluminum tabs
results in littering which is extremely undesirable from an
ecological standpoint. Of course, where the tabs are disposed of on
a beach or other location where they may come in contact with bare
feet, they present a substantial safety hazard.
Finally, aluminum can ends of the ring-tab type are not
particularly easy to open. In general, more than one hand is
required for opening. Furthermore, there is some risk in cutting
one's hand when removing the sharp-edged tab.
Due to the drawbacks of aluminum ring-tab ends, the container
industry has considered the use of steel in easy opening can ends.
Unfortunately, the hardness of steel makes its use in otherwise
conventional ring-tab ends impractical for a number of reasons.
First, the residual scoring thicknesses of a steel can end of this
type must be small and must be maintained within very close
tolerances to assure a line of weakness which will permit removal
of the tabs from the can end. Second, the hardness of steel makes
for a rather short tool life for the punches and dies which are
utilized in scoring the steel.
Because of the foregoing difficulties in utilizing steel in a
ring-tab can end, other types of easy opening steel can ends have
been considered by the container industry. One prior art suggestion
involves the use of a small steel tab which is riveted to the can
end panel. A portion of the tab slides under a raised rim of a
dispensing aperture in the steel end panel. In order to provide a
seal, a sealing material such as plastisol may be utilized on the
underside of the end panel in contact with the tab in the area
surrounding the opening. This arrangement virtually necessitates
the complete separation of the tab from the end panel upon opening.
Although it is possible to slide the tab under the raised rim again
to effect reclosing, separation of the tab from the end panel
usually results in the loss or contamination of the tab. Another
problem resulting from this arrangement is the cost of riveting the
ring to the tab.
Another easy opening steel can end is disclosed in copending
application Ser. No. 150,351 filed June 7, 1971 in the name of this
inventor. As disclosed in that application, the sliding tab is
moved through a track which retains the tab at all times. While
this particular construction solves many of the prior art problems,
it is still difficult to open a sliding tab of this kind due to the
rather substantial internal pressures which bear upon the tab
thereby creating substantial friction between the tab and the edges
of the dispensing aperture. The required opening force is increased
further by the use of a plastic sealant such as plastisol which
forms a hermetic, pressure resistant seal between the tab and the
can end panel at the dispensing aperture. As a result, it is
difficult to open a can end of this type where, as in the case of a
beverage or beer can, the contents of the can are under substantial
internal pressure of the order of 115 p.s.i.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved easy
opening closure which may be opened with substantial ease.
It is a further object of this invention to provide a low cost easy
opening closure.
It is a still further object of this invention to provide an easy
opening closure which is ecologically desirable.
It is a still further object of this invention to provide an easy
opening closure which may comprise steel.
In accordance with these and other objects of the invention, a
preferred embodiment of the invention comprises a closure panel
having a dispensing aperture therein and an at least partially
pre-formed vent hole with an easy opening tab including a sliding
portion closing the dispensing aperture, a flip-over portion having
a hinged connection with the sliding portion and a vent hole
puncturing portion extending from the flip-over portion. Prior to
opening the closure, the flip-over portion is double-backed over
the sliding portion with the vent hole puncturing means extending
away from the closure panel. When the flip-over portion is pivoted
about the hinged connection to a position extending outwardly away
from the closure panel, the puncturing portion engages the closure
panel in the vicinity of the partially pre-formed vent hole. In
accordance with one important aspect of the invention, the
flip-over tab acts as a lever having a fulcrum at a hinge
connection so as to provide a mechanical advantage enabling the
puncturing portion to open the vent hole. In accordance with
another important aspect of the invention, the flip-over portion
continues to pivot about the hinge connection while cooperating
with the panel adjacent the vent hole opening to slide the sliding
portion of the tab to a position opening the dispensing
aperture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view for a can end embodying the invention;
FIG. 2 is a sectional view of the can end of FIG. 1 taken along
section line 2--2;
FIG. 2a is an enlarged sectional view of the can end vent hole
taken along section line 2--2;
FIG. 3 is a sectional view of the can end of FIG. 1 taken along
section line 3--3;
FIG. 4 is an enlarged sectional view of the vent hole and
puncturing projection taken along section line 4--4;
FIGS. 5 and 6 are sectional views of the can end of FIG. 1 taken
along section line 2--2 representing two different phases of the
can opening process;
FIG. 7 is a plan view of another can end embodying the
invention;
FIG. 8 is a sectional view of the can end of FIG. 7 taken along
section line 8--8; and
FIG. 9 is a sectional view of the can end of FIG. 8 taken along
section line 9--9.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIGS. 1 and 2, a steel can end 10 carries a flip-over tab 12
which closes a dispensing aperture 14 in a central end panel 16.
The tab 12 includes a sliding portion 18 which covers the
dispensing aperture 14, a flip-over portion 20 which is adapted to
be engaged by the fingers of the consumer, and a projection 22
which is adapted to puncture a partially pre-formed vent hole 24
located in the central end panel 16.
As best shown in Fig. 3, the sliding portion 18 is held in place
within a track 26 formed by triple-folding the edges 28 along
opposite sides of the dispensing aperture 14. Specifically, the
sides 28 are double-folded over the exterior of the sliding portion
18 with the single fold along the raw edge 30 of the end panel 16
being located on the interior side of the sliding portion 18. The
dispensing aperture is sealed closed by providing a plastic sealant
material 32, e.g., plastisol, along the raw edge 30.
As best shown in FIGS. 1 and 2, the end 34 of the sliding portion
18 which is located adjacent the chuck wall 36 of the end 10 is
received beneath the raised lip 38 of the end panel 16 along the
edge of the dispensing aperture 14. The plastisol 32 also extends
along the end 34 of the sliding portion 18 so as to form a seal
with the end panel 16. Similarly, the plastisol 32 forms a seal
between the sliding portion 18 and the end of the dispensing
aperture adjacent the vent hole 24.
As shown in FIGS. 1, 2, and 2a, the vent hole 24 is partially
pre-formed by lancing the end panel 16 along a 300.degree. arc 40
with a bridging connection 42 to the remainder of the end panel
being located on the side opposite the dispensing aperture 14. This
bridging connection 42 is particularly important since it prevents
the cover 43 which extends over the vent hole 24 from falling into
the cans at the time the can is opened.
The vent hole 24 is maintained in the closed condition by a
plastisol sealant 44 which extends along the 300.degree. arc 40
between the vent hole cover and the remainder of the central panel
along the edge 46 of the partially pre-formed vent hole. Even
though the pressure within the can may reach rather substantial
levels, e.g., 115 p.s.i., the vent hole construction is capable of
preventing the premature venting of the can. In this connection, it
should be appreciated that the lancing of the end panel 16 to form
the partially pre-formed vent hole would produce a friction fit
between the edge 46 of the vent hole along the arc 40 and an edge
48 of the vent hole cover 43. This construction prevents the vent
hole cover 43 from being blown out of the can. Of course, the
plastisol 44 prevents any leakage between the cover and the end
panel at the edges 46 and 48. Furthermore, this particular lanced
configuration is, from the manufacturing standpoint, easy to
achieve. Finally, the vent hole cover 43 is domed or bubbled so as
to achieve the optimum cooperation between the puncturing
projection 22 which is arcuate in cross-section as shown in FIG. 4
and the cover 43 which will now be described with reference to
FIGS. 2, 5 and 6.
In FIG. 2, which represents the closed position, the flip-over
portion 20 of the tab 12 extends back over the sliding portion 18
and the dispensing aperture 14. While the puncturing portion 22 of
the tab 12 extends over the cover 43 of the vent hole 24, the cans
may be stacked end-on-end without danger of damaging the tab or
producing premature opening. Then, by inserting a finger under the
flip-over portion 20 which is facilitated by a depression 50 in the
sliding portion 18, the flip-over portion 20 may be flipped up to a
substantially upright position as shown in FIG. 5. In this
position, the projection 22 has pushed the vent hole cover 43 down
into the interior of the can. Note however, that the bridge 42
remains intact so as to prevent the cover 43 from falling into the
container.
In accordance with one important aspect of the invention, the
flip-over portion 20 acts as a lever arm pivoting at the hinge
connection 52 between the flip-over portion 20 and the sliding
portion 18. The puncturing portion 22 serves as a much shorter
lever arm between the hinge connection 52 and the vent hole to be
punctured. Thus a substantial mechanical advantage is provided to
assist in the opening of the vent hole 24 in the steel end 10 since
the tab itself acts as a tool in opening the partially preformed
vent hole 24. The same result would be achieved if the vent hole
were scored into the steel end since the mechanical advantage
afforded by the tab would permit puncturing of the can end 10 at
the vent hole 24 even if the residual scoring depth tolerances
should vary substantially.
In accordance with another important aspect of the invention, the
projection 22 cooperates with the edge 46 of the vent hole 24 so as
to slide the portion 18 to an open position once the pressure on
the sliding tab has been reduced through venting of the can and the
flip-over portion 20 has been laid against the central end panel 16
in a position opposite the dispensing aperture 14 as shown in FIG.
6. Thus a single motion of the flip-over tab from the position
shown in FIG. 2 to the position shown in FIG. 6 accomplishes
venting of the can which in turn permits the sliding portion 18 to
move with ease to the position shown in FIG. 6 through the
cooperation of the puncturing projection 22 and the vent hole 24.
Actually, the simple opening procedure may be accomplished with one
hand by placing the thumb beneath the double-backed flip-over
portion 20 and moving the tab through an arcuate motion of
180.degree. about the hinge connection 52. Note that the tab 12
remains with the can end 10 after opening which is extremely
advantageous from an ecological and safety standpoint.
In the embodiment of FIGS. 7-9, the sliding tab 12 is substantially
identical to that shown in FIGS. 1-6, but the track which receives
the sliding tab 12 has a somewhat different configuration. In
particular, a raised lip 60 extends along the end 62 of the
dispensing aperture 14 as well as along a substantial portion of
the sides 64 with the raw edges 66 of the end panel 16 being
located on the exterior of the can. Similarly, a raised lip 68
extends along the opposite end portions of the sides of the
aperture 14. The sliding portion 18 of the tab extends through a
slit 72 located at the end of the lip 68 between the aperture 14
and the partially pre-formed vent hole 24. In order to support the
interior side of the tab sliding portion 18, ears or nibs 74 which
are located between the raised lip 60 and the raised lip 68 extend
beneath the sliding portion 18. Plastisol sealant 76 extends along
the slit 72 and around the dispensing aperture 14 so as to provide
a seal for the contents within the can before opening the can end
in the manner shown in FIGS. 1-6.
Since the tab construction serves as a tool offering a mechanical
advantage in the opening of a can end and steel does have certain
ecological advantages, the preferred embodiments have been
described as steel can ends. However, another metal such as
aluminum might be utilized but is by no means necessary in
practicing the invention due to the mechanical advantage inherent
in this tab construction.
In the foregoing specification, the flip-over tab has been
described in terms of a can end adapted to be double-seamed to the
can body as shown in dotted lines in FIG. 2. However, the flip-over
tab of this type could be embodied in a number of different types
of closures for containers including a crown closure for a bottle.
In essence, this would involve a tab-crown closure configuration of
the general type shown in the aforesaid copending application Ser.
No. 150,351.
Although specific embodiments of the invention have been shown and
described in detail, it will be understood that the invention may
be embodied in other forms which will fall within the spirit of the
invention and the scope of the appended claims.
* * * * *