U.S. patent number 3,762,596 [Application Number 05/058,077] was granted by the patent office on 1973-10-02 for easy opening can end.
This patent grant is currently assigned to Van Dorn Company. Invention is credited to George J. Henning, Joseph Scalia.
United States Patent |
3,762,596 |
Henning , et al. |
October 2, 1973 |
EASY OPENING CAN END
Abstract
An outwardly convex elliptical portion is provided in an area
where initial rupture is to occur in the generally circular
end-panel-defining score line located in the can end wall
immediately adjacent the can side wall of an easy open metal can.
Projections are formed in the end wall to locate and hold the can
ring pull tab which is riveted to the end wall in predetermined
position with respect to the elliptical score line portion with the
rounded tab nose overlapping and its axis extending radially of the
end-panel-defining score line. A straight secondary score line
shallower than the end-panel-defining score line and perpendicular
to the axis of the ring pull tab is formed in the can end wall
between the pull tab riveted connection with the end wall and the
elliptical score line portion.
Inventors: |
Henning; George J. (Canton,
OH), Scalia; Joseph (Massillon, OH) |
Assignee: |
Van Dorn Company (Cleveland,
OH)
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Family
ID: |
22014527 |
Appl.
No.: |
05/058,077 |
Filed: |
July 24, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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16451 |
Mar 4, 1970 |
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Current U.S.
Class: |
220/273;
D9/438 |
Current CPC
Class: |
B65D
17/4011 (20180101) |
Current International
Class: |
B65D
17/00 (20060101); B65d 017/20 () |
Field of
Search: |
;220/54,48,53,27
;222/541 ;215/46 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hall; George T.
Parent Case Text
Related Patent and Application
The structures and concepts of the invention are improvements on
the structures set forth in U.S. Pat. No. 3,490,643 of Jan. 20,
1970, and this application is a continuation-in-part of our
copending application, Ser. No. 16,451, filed Mar. 4, 1970, now
abandoned.
Claims
We claim:
1. In metal end wall construction for an easy open can of a type in
which a continuous generally circular marginal score line located
close to the recessed corner of a recessed can end wall seamed to
can side walls defines a removable end panel, and in which ring
pull tab means having a ring portion, side edge portions and a nose
is secured by rivet means to the end panel; the combination of an
elliptically shaped score line portion, in the can circular
end-panel-defining score line, defining the zone of initial rupture
of the score line; the axis of the pull tab means which passes
through the rivet means and nose being radial of that curved
elliptical portion of the score line which the axis intersects, and
being radial of the end-panel-defining score line; means
independent of the rivet means which secures the pull tab means to
the end panel, and engageable with side edge portions of the pull
tab means outside the ring portion of the pull tab means, holding
the pull tab axis in said radial position; the pull tab nose being
rounded, and the rounded portion of the nose extending radially
along said pull tab axis to a position outwardly overlapping the
elliptical score line portion; a secondary straight score line
formed in the end panel perpendicular to said pull tab axis; and
said secondary score line being spaced from each of and extending
between the pull tab rivet means and the elliptical score line
portion.
2. The construction defined in claim 1 in which the elliptical
portion has a flatter curvature than that of the generally circular
marginal score line, and in which the elliptical portion is
connected by more sharply curved portions to the circular marginal
score line.
3. The construction defined in claim 1 in which the pull tab means
has straight side edges, and in which the engageable means includes
buttons projecting from the end panel engaging the pull tab
straight side edges and holding the pull tab means in said radial
position against movement on the rivet means which secures the pull
tab means to the end panel.
4. The construction defined in claim 1 in which the elliptical
score line portion has a greater depth than that of the secondary
score line.
5. Easy open metal can construction including a metal can having a
bottom wall and side walls forming an open upper end, an end wall,
a double seam between the end wall and open upper end of the side
walls, the end wall having a recessed corner below the seam and a
recessed end panel extending from the recessed corner; an
end-panel-defining continuous score line formed in the recessed end
wall corner immediately adjacent the open upper end of the side
walls and double seam; an outwardly convex elliptically shaped
score line portion connected with the remainder of the score line
defining the zone of the initial rupture of the score line and
located further from the can side wall and double seam than the
remainder of the score line; metal pull tab means, rivet means
securing the pull tab means to the end panel, the pull tab means
having a rounded nose, the axis of the pull tab means which passes
through the rivet means and nose being radial of that elliptical
score line portion intersected by the axis, and radial of the
remainder of the end-panel-defining score line; the pull tab means
having a ring portion and side edges outside the ring portion,
means interengageable between the pull tab side edges and end panel
holding the pull tab means axis in said radial position; the
rounded nose overlapping and extending slightly outward beyond the
elliptical score line portion; and a secondary straight score line
formed in the end panel perpendicular to said pull tab axis, the
elliptical score line portion having greater depth than that of the
secondary score line, the secondary score line being spaced from
and located between the pull tab rivet means and the elliptical
score line portion, and the secondary score line and elliptical
score line portion defining a flap-like portion which bends on the
secondary score line when the elliptical score line portion is
initially ruptured.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to easy open metal cans in which a ring pull
tab is riveted to a can end wall seamed to the open end of can side
walls wherein pulling of the pull tab removes an end panel from the
can providing a full opening permitting complete access to and
removal of the can contents. More particularly the can end wall,
score lines, ring pull tab, and end wall formations are so
arranged, located, and coordinated that the end wall may be
properly connected to the can side walls with a usual double seam
while permitting full opening of the can upon end panel removal;
that assures proper initial rupture of a predetermined portion of
the score line and proper distortion of a predetermined area of the
end panel upon movement of the ring pull tab; and that insures
bending of a small flap-like portion of the end panel on a straight
line upon initial rupture of the can end wall for opening the
can.
2. Description of the Prior Art
The construction and arrangement of the can end wall, score lines,
ring pull tab, and the rounded nose of the ring pull tab in the
easy open can shown in U.S. Pat. No. 3,490,643 provides very
advantageous characteristics for the can facilitating easy opening
of the can, and enabling complete access to the can contents while
protecting the raw metal edge of the can end metal where the end
panel is torn from the end wall from accidentally cutting the
user.
This feature results from the location of the end-panel-defining
score line very close to the recessed corner of the end wall just
below the zone of the double seam connecting the end wall to the
can side walls. The proper initial rupture of the end panel along
the score line depends upon the location of the rounded nose of the
ring pull tab overlapping and extending slightly outward beyond the
score line. Thus, the location of the score line and extended pull
tab nose leaves little room for the chuck of the seaming tool to
engage and hold the recessed corner of the can end wall during the
seaming operation. Difficulties with chuck wear and breakage and
with faulty seams thus have arisen because of the closeness of the
tab nose to the recessed corner of the can end wall.
Proper and easy opening of the cans shown in U.S. Pat. No.
3,490,643 also depends upon the accurate positioning of the ring
pull tab with its nose and rivet connection aligned radially of the
can and score line. The rivet-like connection of the ring pull tab
with the can end wall has been found to permit the tab to be turned
or rotated accidentally or intentionally out of proper exact
position. An improperly located or positioned pull tab normally
will prevent easy and correct tearing out of the can end panel.
Also the rate of curvature of the tear-out score line is such that
a considerable zone of the score line is involved in the initial
rupture, and as a consequence a considerable area of the end panel
also is involved in the initial distortion and bending of the end
panel as it is ruptured and peeled from the can. These factors and
particularly when accompanied by improperly located ring pull tabs
have caused difficulties in opening the cans.
SUMMARY OF THE INVENTION
Objectives of the invention include providing a predetermined
outwardly convex elliptical score line portion at the zone of
initial rupture connecting in curved fashion with the remaining
score recessed zone located close to the recesses corner of the can
end wall seamed to the can, so that the elliptical score line
portion is spaced further from the recessed end wall corner than
the remainder of the normally circular end-panel-defining score
line and so that the elliptical score line portion determines the
zone of initial rupture and directs the rupture along a smoothly
curved line without resistance; providing means for locating in
exact predetermined position and for holding in such position the
ring pull tab as it is being connected or riveted to and after
being connected to the can end wall so that the pull tab axis
extends radially of the end-panel-defining score line or radially
of that curved elliptical portion which the axis intersects;
providing a secondary straight score line in the can end wall
perpendicular to the axis of the pull tab and of lesser depth than
that of the elliptical score line portion, and located spaced from
and between the tab rivet connection with the can end wall and the
elliptical score line portion; and providing for elimination of
difficulties heretofore encountered, and achieving the stated
objectives simply, effectively, and inexpensively.
These objectives and advantages are obtained by the easy opening
metal can and can end construction, the general nature of which may
be stated as including a metal can end wall adapted to be secured
to the side walls of a metal can by a usual double seam, the end
wall having a recessed end panel extending from a recessed corner,
the corner being located below the seam; an end-panel-defining
continuous score line formed in the end wall very close to the
recessed corner, a predetermined portion of the score line being
outwardly convexly elliptically shaped and being connected with the
remainder of the end-panel-defining score line by smoothly curved
portions defining the zone of initial rupture of the score line,
and the score line including the elliptical portion providing a
tear line on which the end panel may be torn from the end wall
member; metal pull tab means, rivet means securing the pull tab
means to the end panel, the pull tab means having a projecting
rounded nose, and the axis of the pull tab means passing through
the center of the rivet means and the center of the rounded nose
extending radially of the end-panel-defining score line and
radially of that elliptically curved portion which the pull tab
axis intersects; projection means engageable between the pull tab
means and end panel holding the pull tab means located in the
position with its axis extending radially of the end-panel-defining
score line; a secondary straight score line in the can end wall
perpendicular to the axis of the pull tab and of lesser depth than
the elliptical score line portion; said secondary straight score
line being located between and spaced from the rivet means and the
rounded pull tab nose; and the rounded nose of the pull tab means
being located in a position overlapping and extending slightly
outward beyond the elliptical score line portion.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention -- illustrative of the best
modes in which applicants have contemplated applying the principles
-- are set forth in the following description and shown in the
drawings and are particularly and distinctly pointed out and set
forth in the appended claims:
FIG. 1 of the drawings is a top plan view of a can provided with
the new can end wall structure;
FIG. 2 is a vertical section on a larger scale taken on the line
2--2, FIG. 1 showing the new structure;
FIG. 3 is a perspective view of the can shown in FIGS. 1 and 2,
with parts broken away, showing the initial stage of manipulating
the pull tab for end panel removal,
FIG. 4 is a fragmentary sectional view on line 4--4, FIG. 5, on a
further enlarged scale showing the pull tab in the position shown
in FIG. 3;
FIG. 5 is a fragmentary plan view of the parts in the position of
FIGS. 3 and 4;
FIG. 6 is a perspective view similar to FIG. 3 showing the removed
end panel and pull tab illustrated in FIGS. 1 to 5;
FIG. 7 is a view similar to FIG. 1 of a smaller sized can provided
with the new can end wall structure;
FIG. 8 is a sectional view similar to FIG. 2 of the can shown in
FIG. 7, taken on the line 8--8, FIG. 7;
FIG. 9 is a view similar to FIGS. 1 and 7 of a still smaller sized
can provided with the new can end wall structure;
FIG. 10 is a bottom plan view of the can illustrated in FIG. 9;
FIG. 11 is a vertical section looking in the direction of the
arrows 11--11, FIG. 9 illustrating two of the cans shown in FIG. 9
stacked one on top of the other;
FIG. 12 is an enlarged fragmentary section illustrating the
relative depths of the predetermined and secondary score lines;
and
FIG. 13 is a fragmentary section taken on the line 13--13, FIG.
1.
Similar numerals refer to similar parts throughout the
drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
The invention is illustrated typically in FIGS. 1 through 6 and 12
and 13 as applied to a large sized can, an intermediate sized can
being illustrated in FIGS. 7 and 8, and a small sized can in FIGS.
9 through 11.
A can 1, generally of conventional construction, has a cup-shaped
body with a bottom wall 2 and side walls 3, and a can end wall 4 is
connected by a usual double seam 5 to the upper or open end of side
walls 3. End wall 4 has a recessed corner 6 at the lower end of
double seam 5 seated on a ledge 7 formed adjacent the upper end of
side walls 3, and a curved score line 8 is formed in the end wall 4
very close to the recessed corner 6. The score line 8 defines an
end panel 9 which is completely removable from the remainder of the
end wall 4 when torn or peeled along score line 8 to provide a
fully open top for the can 1.
A ring pull tab 10 preferably is connected by a rivet formation 11
with the end panel 9 which may be made in any conventional manner
or may be accomplished as set forth in Henning et al. U.S. Pat. No.
3,346,948. Ring pull tab 10 preferably is formed of sheet metal of
somewhat heavier gauge than the sheet metal from which can 1 and
end wall 4 are formed. Members 1, 4 and 10, preferably, but not
necessarily, may be formed of aluminum. End wall 4 and ring pull
tab 10 as thus far generally described may be made as shown in
Henning et al. U.S. Pat. No. 3,490,643.
In accordance with the invention, a predetermined portion 12 of the
score line 8 which forms the zone of initial rupture is formed to
have an outwardly convex elliptical shape, as shown, and connects
with the remainder of the score line 8 by smoothly curved portions.
Pull tab 10 has a rounded nose 13 located in a position, as shown,
slightly overlapping and extending slightly outward beyond the
elliptical score line portion 12. The axis 14 of pull tab 10, which
passes through the center of rivet 11 and the center of rounded
nose 13 is radial with respect to the score line 8 and radial to
that curved elliptical portion which axis 14 intersects. A pair of
buttons or projections 15 are formed projecting upward of the end
panel 9 on either side of the pull tab 10 and its axis 14. Buttons
15 engage straight side edge portions OF the pull tab 10 outside
the ring portion, as shown in FIGS. 1, 5, 7 and 9 and hold pull tab
10 in the described radial position and prevent pull tab 10 from
accidentally turning on rivet 11. In this manner the pull tab is
held in proper position with respect to the elliptical score line
portion 12 so that the initial rupture of the score line 8 can be
accomplished properly and easily. Also, the buttons 15 function to
center and locate pull tab 10 as it is being riveted at 11 to the
end wall 4.
A secondary straight score line 16 is formed in end panel 9
perpendicular to pull tab axis 14, and extends between and is
spaced from the rounded nose 13 and rivet 11. Score line portion 12
and score line 8 have a greater depth (FIG. 12) than secondary
score line 16. For example, where the end wall 4 is 0.012 inch
sheet metal, score line portion 12 and score line 8 may leave a
residual metal thickness of 0.003 inch and secondary score line 16
may leave a residual metal thickness of 0.008 inch.
The opening of can 1 is shown in FIGS. 1, 3, 4, 5, and 6. FIG. 1
shows the parts in normal position with the can closed or sealed.
Pull tab 10 is grasped and pulled upward initially to the position
shown in FIGS. 3, 4, and 5. The tab nose 13 wipes across straight
score line portion 12 where the initial rupture occurs. The metal
bends readily on secondary score line 16 and a flap-like portion 17
is distorted downward as shown in FIG. 4. This rupture occurs
readily, the down-tear occurring easily and smoothly along curved
portion 12 outward from either side of rounded nose 13. The
secondary score line 16 permits ready bending along score line 16
and thus permits flexing of the flap-like portion 17 as the metal
is torn along score line portion 12.
After the initial rupture along line 12 and distortion of flap-like
portion 17, the metal in end wall 4 tears along score line 8 from
either end of portion 12 circumferentially in both directions quite
easily as the tab is continued to be pulled upward until end panel
9 is completely severed when it has the shape shown in FIG 6.
It has been discovered that where any corner-like portions occur in
the complete score line which defines the end panel removed, some
resistance to tearing occurs at such corners. Further, any such
score line corner-like portions may contribute to possible score
line breakage from bumping in handling and shipment of a filled
can.
The particular elliptical shape of the score line portion 12
eliminates these problems. That elliptical portion 12A overlapped
by the rounded pull ring nose 13 has a greater radius of curvature
and thus is flatter than the radius of curvature of the main end
panel defining score line 8. More sharply curved elliptical
portions 12B smoothly connect the flatter elliptical portion 12A
with the main score line 8, as indicated in FIG. 5.
Thus, the elliptical shape of the score line portion 12 at the area
of initial rupture provides most efficient and smooth continuous
breaking along the score line portions from the pressure and pull
of the pull ring 10. At the same time the bending of the flap-like
portion 17 along secondary score line 16 eliminates pressure on the
rivet 11 as the pull ring 10 is manipulated.
Second Embodiment
A medium or intermediate sized can 18 and can end wall 19 are shown
in FIGS. 7 and 8 which are very similar to the can 1 and can end
wall 4 of FIGS. 1 and 2. Can end 19 has a score line 20 with an
elliptical score portion 21 which is ruptured by rounded nose 22 of
pull tab 23 when end wall flap-like portion 21a bends on secondary
straight score line 21b. Tab 23 is held in proper position by
buttons 24. End wall 19 has two rounded upwardly projected bosses
or knobs 25 preferably located triangularly with respect to pull
tab 23 so as to form a three point support for cans 18 when in a
stack one above another. The can 18 of FIGS. 7 and 8 contains all
the new features, and operates the same way and obtains the same
results as the can 1 of FIGS. 1 and 2. FIG. 7 shows clearly the
differing curvatures of the elliptical portion 21 and main score
line 20 because of the smaller size and sharper curvatures in can
18 as compared to can 1.
Third Embodiment
A small sized can 26 and can end wall 27 are shown in FIGS. 9, 10,
and 11, similar to the can 1 and can end wall 4 of FIGS. 1 and 2;
and also similar to the can 18 and can end 19 of FIGS. 7 AND 8.
Can end 27 has a score line 28 with an elliptical score line
portion 29 which is ruptured by rounded nose 30 of pull tab 31. Tab
31 is held in proper position by buttons 32. Knobs or bosses 33
permit stacking of the cans 26 as shown in FIG. 11, the tabs 31
avoiding interference when stacked because of the special bottom
formation 34 illustrated in FIGS. 10 and 11.
Can end 27 also has a secondary score line 35 to facilitate bending
of the initially distorted portion 36 of the end panel as it is
torn from end wall 27.
The improved construction combines a number of important improved
features and advantages over the construction of U.S. Pat. No.
3,490,643 resulting from the shape and location of an elliptical
score line portion for the zone of initial rupture, from
maintaining the pull tab radially located and from the provision of
the secondary straight score line to facilitate initial rupture
bending of the removed end panel; and provides structures which
eliminate difficulties encountered with prior devices; and provides
structures which achieve the objectives and solve problems existing
in the art in a simple manner.
In the foregoing description, certain terms have been used for
brevity, clearness, and understanding; but no unnecessary
limitations are to be implied therefrom beyond the requirements of
the prior art because such terms are used for descriptive purposes
and are intended to be broadly construed.
Moreover, the description and illustration of the invention is by
way of example, and the scope of the invention is not limited to
the exact details shown or described since the features of the
invention may be applied to end walls for different sized cans.
Having now described the features, discoveries and principles of
the invention, the manner in which the improved structures are
made, assembled and used, the characteristics of the new
construction, and the advantageous, new and useful results
obtained; the new and useful structures, devices, elements,
arrangements, parts, combinations, and subcombinations, and the
cooperative relationship therebetween, and mechanical equivalents
obvious to those skilled in the art are set forth in the appended
claims.
* * * * *