Note: Descriptions are shown in the official language in which they were submitted.
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CLOSURE WITH MULTIPLE
AXIS BISTABLE HINGE STRUCTURE
TECHNICAL FIELD
This invention relates to container closures.
The invention is particularly suitable for use with a
squeeze-type container dispensing closure which can be
opened to dispense a fluid product from the container
when the container is squeezed.
BACKGROUND OF THE INVENTION
TECHNICAL PROBLEMS POSED BY THE~PRIOR ART
A variety of packages, including dispensing
packages or containers, have been developed for personal
care products such as shampoo, lotions, etc., as well as
L5 for other fluid materials. One type of closure for
these kinds of containers typically has a bistable hinge
structure connecting a lid to a base mounted over the
.container opening. The hinge structure has a snap-
action biasing force which maintains the lid in a
selected closed or open position.
One type of bistable hinge structure
incorporated in a closure is disclosed in U.S. Patent
No. 3,1.35,456. This patent discloses a snap-action
hinge structure comprising a thin hinge web joining a
base and a lid to accommodate movement of the lid
between an open and closed position. The hinge
structure has two, spaced-apart pivot axes. In
particular, the hinge structure incorporates two,
spaced-apart film hinges, one film hinge having an
arcuate configuration connecting the lid to the hinge
web and the other film hinge having an arcuate
configuration connecting the base to the hinge web. The
' two pivot axes are defined by two parallel lines
wherein, at points where the two film hinges are closest
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to each other, one Line is tangent to the lid film hinge
and the other line is tangent to the body film hinge.
The multiple axis hinge structure disclosed a.n
U.S. Patent No. 3,135,456 does not include a single,
fixed geometric pivot axis such as is employed in the
type of snap-action hinge for a cylindrical closure
disclosed in U.S. Patent No. 4,403,712. The hinge
structure disclosed in the U.S. Patent No. 3,135,456
operates in a different manner. Further, the multiple
axis hinge structure disclosed in U.S. Patent No.
3,135,456 accommodates certain design and manufacturing
advantages. For example, the two spaced-apart film
hinges can be more easily manufactured without stress
risers because there is no need to vary the thickness of
the film hinges along the length of the film hinges.
In contrast, the hinge structure for a
cylindrical closure disclosed in U.S. Patent No.
4,403,712 has a single, main geometric axis film hinge
and has two film hinges which diverge. In commercial
embodiments of the cylindrical closure having a single
axis hinge structure disclosed in the U.S. Patent No.
4,403,712, the film hinge thickness changes along the
1ength of the film hinges. The thickness transition
regions can define stress risers which may ultimately
have a deleterious effect upon the structure during
repeated operation.
The multiple axis hinge structure disclosed in
the U.S. Patent No. 3,135,456 has manufacturing
advantages over the single geometric axis type hinge
disclosed in U.S. Patent No. 4,403,712. In particular,
the less complex hinge geometry of the hinge structure
disclosed in U.S. Patent No. 3,135,456 simplifies design
work, tooling construction and maintenance, inspection,
and quality control procedures for products
incorporating such a design.
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Further, owing to the uniform cross-sectional
thickness of the multiple film hinges along the lid and
body circumferences, the hinge structure disclosed in
the U.S. Patent No. 3,135,456 can be molded more
uniformly by means of injection molding. This prevents,
or substantially minimizes, weld line formation in the
web between the two film hinges, particularly along the
film hinge which attaches the web to the lid.
While the hinge structure disclosed in U.S.
Patent No. 3,135,456 offers numerous advantages over
single pivot axis hinge structures, it\would be
desirable to provide an improved design in which the
opening and closing action of the hinge structure could
be more carefully controlled.
I5 Further, it would be beneficial if such an
improved design could more readily accommodate
incorporation in closures having different types of lid
and base configurations and different sizes.
In particular, it would be especially
desirable to provide a hinge structure which would
accommodate simple design changes to provide a hinge
biasing force of a desired magnitude. For example, in
some applications, a smaller biasing force is desired to
provide a "soft" opening and closing action. In other
applications, a larger biasing force is desired to
provide an opening and closing action with greater
"snap."
A smaller biasing force can result in the lid
having a relatively small full opening angle with
respect to the base. A larger biasing force can result
in the lid having a relatively large full opening angle
relative to the base. An improved hinge structure
design should preferably accommodate the incorporation
of a relatively simple design change so as to provide a
closure having the desired opening and closing angle
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range. A hinge structure with such a capability can
provide performance features that are most desirable in
a particular application.
Also, it would be desirable if such an
improved closure could be provided with a design that
would accommodate efficient, high quality, large volume
manufacturing techniques with a reduced product reject
rate.
Further, such an improved closure should
advantageously accommodate its use with a variety of
conventional containers having a variety of conventional
container finishes, such as conventional threaded or
snap-fit attachment configurations.
The present invention provides an improved
closure which can accommodate designs having the above-
discussed benefits and features.
SUMMARY OF THE INVENTION
According to the present invention, a closure
is provided for an opening to a container interior. The
closure includes a base for mounting to the container
over the opening. The base defines a discharge aperture
communicating with the opening. The closure includes a
lid movable between a closed position occluding the
aperture and an open position spaced from the aperture.
A bistable, snap-action hinge structure connects the lid
to the base.
The hinge structure is of the type that
includes a web having a central portion between two
wider ends wherein an arcuate film hinge connects the
base to the web along one side of the web between the
ends and wherein an arcuate film hinge connects the lid
to the web along another side of the web between the '
ends. The hinge structure includes at least one
abutment surface located so that when the lid is in the
closed position, the abutment surface extends adjacent
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the web central portion from near one of the film hinges
toward the other film hinge more than one-half the
shortest distance between the film hinges. During the
closing and opening of the lid, the abutment surface is
contacted by the web central portion whereby the
position of the web is controlled.
In a preferred form of the invention, the
abutment surface is unitary with the base. The base has
a recessed shoulder adjacent the web ends for
~.0 accommodating seating of the lid thereon when the lid is
in the closed position. The abutment surface is
oriented perpendicularly relative to the base shoulder
adjacent the web central portion. The base has a first,
cylindrical arc surface projecting up from the inside of
the recessed shoulder, and the base defines an edge at
the top of the cylindrical arc surface. The first
cylindrical arc surface has a first radius. The film
hinge that connects the base and the web is axially
spaced from the first cylindrical arc surface top edge.
The abutment surface is defined by a second
cylindrical arc surface having a second radius less than
the first radius. The second cylindrical arc surface
(which defines the abutment surface) projects beyond the
first cylindrical arc surface toward the hinge web
between the web ends. The location of the abutment
surface, the shape of the abutment surface, and the
height of the abutment surface along the web of the
hinge structure can be varied to increase or decrease
the contact between the web and the abutment surface
upon closing or opening the lid. This controls the
location of the web as the lid is closed or opened.
' This interaction, as established by the location, shape,
and size of the abutment surface, results in a
predetermined hinge structure biasing force (e.g., the
opening and closing force). This permits the hinge
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structure to be designed to provide a low biasing force
(i.e., a "soft" hinge action) or a greater hinge biasing
force to provide a more "snappy" hinge action.
Numerous other advantages and features of the
present invention will become readily apparent from the
following detailed description of the invention, from
the claims, and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings forming part of
the specification, in which like numerals are employed
to designate like parts throughout the\same,
FIG. 1 is a perspective view of a first
embodiment of a closure of the present invention shown
in the as-molded open position;
FIG. 2 is a top plan view of the closure in
the fully open, as-molded condition;
FIG. 3 is a front elevational view of the
closure base taken generally along plane 3-3 in FIG. 2;
FIG. 4 is a cross-sectional view taken
generally along the plane 4-4 in FIG. 2;
FIG. 5 is a cross-sectional view taken
generally along the plane 5-5 in FIG. 2;
FIG. 6 is a greatly enlarged, fragmentary, top
plan view of the hinge structure region of the closure
shown in the fully open, as-molded condition in FIG. 2;
FIG. 7 is a fragmentary, cross-sectional view
taken generally along the plane 7-7 in FIG. 6;
FIG. 8 is a fragmentary, cross-sectional view
taken generally along the plane 8-8 in FIG. 6;
FIG. 9 is a fragmentary, cross-sectional view
taken generally along the plane 9-9 in FIG. 6;
FIG. 10 is a fragmentary, cross-sectional view ~
taken generally along the plane 10-l0 in FIG. 8;
FIG. I1 is a view similar to FIG. 2 but FIG.
zl is shown in a reduced scale;
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FIG. 12 is a fragmentary, cross-sectional view
taken generally along the view plane A-A in FIG. 11;
FIG. 13 is a view similar to FIG. 12, but FIG.
13 shows the lid moved 30° from the full open positions
of FIGS. 11 and 12 to a partially closed position that
is 30° from the full open position;
FIG. 14 is a fragmentary, cross-sectional view
taken generally along the plane B-B in FIG. 11, but FIG.
14 shows the lid rotated 30° from the full open position
to the same orientation as illustrated in FIG. 13;
FIG. 15 is'a view similar to'FIG. 13, but FIG.
shows the lid moved to a position 90° from the full
open position;
FIG. 16 is a view similar to FIG. 15, but FIG.
15 16 shows the lid moved 150° away from the full open
position;
FIG. 17 is a view similar to FIG. 16, but FIG.
17 shows the lid fully closed on the base;
FIG. 18 is a fragmentary, rear elevational
view of the closure with the lid in the fully closed
position;
FIG. 19 is an enlarged,. fragmentary cross-
sectional view similar to FIG. 14 and is taken along the
plane B-B in FIG. 11, but FIG. 19 shows the lid in a
less open position than do FIGS. 11 and 14; and
FIG. 20 is an enlarged, fragmentary cross-
sectional view similar to FIGS. 14 and 19, and FIG. 20
is taken along the plane B-B in FIG. 11, but FIG. 20
shows the lid in an even less open position than does
' 30 FIG. 19;
FIG. 21 is an enlarged, fragmentary cross-
sectional view similar to FIG. 14 taken along the plane
B-B in FIG. 11, but FIG. 21 shows the lid in a fully
closed position; and
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FIG. 22 is a perspective view of a second _
embodiment of the closure of the present invention shown
in the fully open, as-molded position.
DESCRIPTION OF TFiE PREFERRED EMBODIMENTS
While this invention is susceptible of
embodiment in many different forms, this specification
and the accompanying drawings disclose only some
specific forms as examples of the invention. The
invention is not intended to be limited to the
embodiments so described, and the scope of the invention
will be painted out in the appended claims.
For ease of description, the closure of this
invention is described in various positions, and terms
such as upper, lower, horizontal, etc., are used with
reference to these positions. It will be understood,
however, that the closure may be manufactured and stored
in orientations other than the ones described.
With reference to the figures, a first
embodiment of a closure of the present invention is
illustrated in FIGS. 1-21 and is represented generally
in many of those figures by reference numeral 40. The
closure 40 is adapted to be disposed on a container,
such as a container 42 (FIG. 1) which has a conventional
mouth or opening (not visible) formed by a neck 43 (FIG.
1) or other suitable structure. The neck 43 typically
has a circular cross-sectional configuration, but the
body of the container 42 may have another cross-
sectional configuration, such as an oval cross-sectional
shape, for example. The closure 40 may be fabricated
from a thermoplastic material, or other materials, .
compatible with the container contents.
The container 42 may be stored and used in the
orientation shown in FIG. 3 wherein the closure 40 is at
the top of the container 42. The container 42 may also
be normally stored in an inverted position (not
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illustrated). When stored in the inverted position, the
container 42 employs the closure 40 as a support base.
The container 42 is a squeezable container
having a flexible wall or walls which can be grasped by
the user and compressed to increase the internal
pressure within the container 42 so as to squeeze the
product out of the container when the closure 40 is
opened (as explained in detail hereinafter). The
container wall typically has sufficient, inherent
resiliency so that when the squeezing forces are
removed, the container wall returns to its normal,
unstressed shape.
The closure 40 includes a base or body 50 for
being mounted to the container neck 43. The base 50
includes an annular wall 52 (FIG. 5) which has a
conventional thread 54 or other suitable means (e.g., a
conventional snap-fit bead (not illustrated)) for
engaging suitable cooperating means, such as a thread
(not visible) on the container neck 43 to secure the
closure base 50 to the container 42.
At the top of the closure base annular wall
52, the closure base has a transverse deck 56 (FIG. 5)
which extends over the upper, distal end of the
container neck 43. The deck 56 has a downwardly
extending, annular, internal flexible seal 58 (FIG. 5)
which is received against the inner edge of the
container neck 43 in the container neck opening so as to
provide a leak-tight seal between the closure base deck
56 and the container neck 43.
As illustrated in FIGS. 1 and 5, the closure
base deck 56 has a spout 62 projecting upwardly to
. define a discharge aperture 60 over the container neck
opening.
The closure 40 includes a lid 70 (FIG. 1)
connected to the base with a hinge structure 80. The
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lid 70 includes a peripheral skirt 82 (FIG. 5) defining
a peripheral termination surface 84. The lid peripheral
surface 84 is adapted to contact or at least confront
the closure base 50 when the lid 70 is closed.
Preferably, as illustrated in FIG. 1, the closure base
50 defines a peripheral shoulder 86 recessed below the
main portion of the deck 56, and the recessed shoulder
86 confronts the surface 84 of the lid skirt 82 when the
lid 70 is closed.
IO The closure lid 70 includes a transverse deck
or cover 88 (FIG. 5): Extending from the underside of
the lid cover 88 is an annular sleeve 90 which is
adapted to be received on, and sealingly engage the
exterior of, the closure base spout 62 when the lid 70
is closed.
The closure lid 70 also preferably includes
an annular sealing collar 94 (FIGS. 1 and 5) which seals
against the closure base 5o when the lid 70 is closed.
In particular, the closure base 50 defines a vertical
wall 98 joining the spout 62 to the deck 56. In FIG. 6,
the arcuate lines 99 represent the limits of small radii
edge surfaces at the top and bottom of the wall 98.
When the lid 70 is closed, the lid annular sealing
collar 94 sealingly engages the annular wall 98 on the
closure base 50.
In the preferred embodiment, the hinge 80 is
integrally molded as a unitary part of the closure with
the base 50 and lid 70. One preferred material for
molding the closure is polypropylene. It has been found
that this material provides a relatively strong, durable
closure. The material functions in the hinge structure
80 with desirable biasing forces, has the capability for
withstanding typical loads imposed by a user of the
closure when the user opens and closes the lid, and has
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the capability for accommodating a relatively high
number of opening and closing cycles without failure.
The hinge structure 80 includes a web 100
having a central portion between two wider ends.102.
The two ends 102 are generally parallel in the preferred
embodiment illustrated.
A first, arcuate film hinge 121 connects the
base 50 to the web 100 along one side of the web 100
between the ends 102. A second, arcuate film hinge 122
to connects the lid 70 to the web 100 along another side of
web 100 between the ends 102. As illustrated in FIG. 6,
the first film hinge 121 lies on an arc concentric with
the circumference of the closure base 50, and the second
film hinge 122 lies on an arc concentric with the
circumference of the lid 70. As illustrated in FIGS. 8
and 18, the first film hinge 121 lies in an upwardly
convex curve on the side of the closure base 50. As
illustrated in FIGS. 9 and 18, the second film hinge 122
lies on an upwardly convex curve on the side of the
closure lid 70.
In a preferred embodiment as illustrated in
FIGS. 6, 7, and 10, the inner surface of the first film
hinge 121 has a particular configuration when the lid is
fully open. Specifically, the inner surface of the
first film hinge 121 (when the lid is fully open) has a
curved, radius surface defined between the arcuate line
128 and another arcuate line 132. Adjacent the base
side of the film hinge 121 there is a radius surface 124
defined between the arcuate line 128 and an arcuate line
126. The arcuate line 126 defines the locus of tangency
between the radius surface 124 and an adjacent shoulder
surface 136 on the base 50. The arcuate line 128
defines the locus of tangency between the radius surface
124 and the radius surface of the first film hinge 121.
The arcuate line 132 defines the locus of tangency
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between the radius surface of the first film hinge 121 _
and the adjacent~portion of the web 100.
In a preferred, contemplated commercial
embodiment wherein the closure 40 is fabricated from
polypropylene, the radius of the surface 124 is 0.01
inch, the radius of the upwardly facing inner surface of
the film hinge 121 (as viewed in FIG. 6) is 0.03 inch,
and the thickness of the web 100 is 0.012 inch.
The second film hinge 122 has a configuration
generally identical to that of the first film hinge 121,
except that the second film hinge 122,'of course, is
oriented in the opposite direction to connect the web
100 to the lid '70. When the lid is fully opened (FIG.
6), the inner surface of the second film hinge 122 has a
curved, radius surface defined between an arcuate line
128A and an arcuate line 132A. Along the lid side of
the second film hinge 122 there is radius surface 124A.
The radius surface 124A is defined the between the
arcuate line 128A and an arcuate line 126A.
The arcuate line 126A defines the locus of
tangency between the radius surface 124A and an adjacent
shoulder 136A on the lid 70. The arcuate line 128A
defines the locus of tangency between the radius surface
124A and the adjacent radius surface of the second film
hinge 122. The line 132A defines the locus of tangency
between the radius surface of the second film hinge 122
and the adjacent portion of the web 100.
The second film hinge 122 preferably has the
same configuration and dimensions as the first film
hinge 121. Therefore, the radius of surface 124A and .
the radius of the surface of the film hinge 122 are
equal to the radius of surface 124 and the radius of
surface of the first film hinge 121, respectively.
With reference to FIG. 7, when the lid 70 is
fully open, the radius surface along the outside of each
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film hinge 121 and 122 along the exterior of the web is
designated by the reference numeral 140. In the
preferred, contemplated commercial embodiment, the
' radius of the surface 140 is 0.012 inch.
The hinge structure 80 is accommodated in the
closure base 50 by a notch 142 defined in the closure
base wall 52 (FIG. 8). Similarly, the hinge structure
80 is accommodated in the closure lid 70 by a notch 144
in the closure lid skirt 82 (FIG. 9).
Preferably, the web 100 is substantially
symmetric about a centerline 135 (FIG.\6). Another line
137 is perpendicular to the centerline 135 and passes
through the centers of the closure base 50 and closure
lid 70. The distance between the centerline 135 and the
. 15 intersection of the line 137 with the film hinge 121
equals the distance between the centerline 135 and the
intersection of the line 137 with the film hinge 122.
The view line 8-8 in FIG. 6 is at the midpoint
between the centers of the lid 70 and base 50. If the
radius of the closure base connection to the film hinge
121 equaled the radius of the closure lid connection to
the film hinge 122, then the film hinges 121 and 122
could also be symmetrically oriented about the closure
midpoint (view line 8-8 in FIG. 6). Typically, however,
the maximum outside diameter of the shoulder 86 on the
closure base wall 52 is about 0.01 inch greater than the
maximum outside diameter of the lid skirt 82 at the lid
skirt confronting surface 84. As a consequence, the
midpoint of the hinge structure 80 along the line 137 is
offset slightly toward the lid compared to the point
mid-way between the centers of the lid 70 and base 50
(marked by the intersection of view line 8-8 with line
137) .
The hinge structure 80 central portion web 100
is narrower than the two ends 102. The widest part of
~
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the hinge structure 80 occurs at each end I02.
Preferably, the widths of the two ends 102 are equal. A
major portion of the width of each end 102 is defined by
a straight line segment 102'. The straight line segment
102' is symmetrically disposed relative to the
longitudinal centerline 135 of the hinge structure 80.
At each end of the segment 102', the end of the first
film hinge 121 is defined by an edge 102 " , and the end
of the second film hinge 122 is defined by an edge
102A " . The edges 102 " and 102A " slant or curve
slightly toward the centerline 137 of the closure, which
centerline 137 passes through the centers of the closure
base 50 and closure lid 70.
Each end of the radius surface 124 is defined
by an edge 102 " ', and each end of the radius surface
124A is defined by an edge 102A " '. Each edge 102 " '
and 102A " ' curves or slants from the edge 102 " and
102A " , respectively, so that the edge joins the
shoulder or surface 136 and 136A, respectively, at an
orientation that is substantially parallel to the
closure centerline 137 joining the centers of the
closure base and lid.
In the preferred embodiment illustrated in
FIGS. 1-21, the shoulder 136 decreases in width from
each end of the hinge structure 80 toward the middle of
the hinge structure 80 where the width of the shoulder
136 becomes very small or, preferably, substantially
disappears. This occurs because a novel abutment
surface 150 (FIG. 6) is provided for controlling the
position of the web 100 upon the closing or opening of
the lid 70. In the preferred embodiment illustrated,
the abutment surface 150 is molded as a unitary part of
the closure base 50.
The abutment surface 150 projects outwardly
from the closure base 50. The closure base 50 has a
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generally vertically oriented, cylindrical surface 15.8
(FIGS. 3 and 7) which extends from the hinge notch 142
above the top of the abutment surface 150. The
cylindrical surface 158 extends around the circumference
of the closure base deck 56, and the peripheral shoulder
86 projects outwardly therefrom on either side of the
hinge notch 142.
The abutment surface 150 projects outwardly
from the surface 158 as shown in FIGS. 6,7 and 8. A
horizontal ledge 162 is defined at the top of the
abutment surface 150~and projects from~the cylindrical
surface 158. In FIG. 6, arcuate line 155 is the inner
end of a radius surface defining the top edge of the
cylindrical surface 158. The outer edge of the ledge
162 is defined by a convex radius surface 164 (FIGS. 6
and 83 which merges with the vertical abutment surface
150. In a presently contemplated commercial embodiment,
the surface 164 has a radius of about 0.01 inch.
The arcuate film hinge 121 is spaced below the
deck 56, below the ledge 162 at the top of the abutment
surface, and below. the shoulder surface 86 at either
side of the hinge notch 142.
In the region of the hinge structure 80, the
closure base notch 142 in the closure base annular wall
52 is defined along its bottom by the shoulder 136
(FIGS. 6 and 10) which decreases in width toward the
center of the hinge structure 80. Adjacent the central
portion of the hinge structure 80, the width of the
shoulder surface 136 decreases to nearly zero as the
protruding abutment surface 150 projects further
outwardly into the surface 136.
. The radius of the cylindrical surface 158 (at
the outer edge of the deck 56 adjacent the hinge
structure 80} is larger than the radius of the exterior,
vertical surface of the abutment surface 150. Moreover,
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both the inner and outer radii of the shoulder 136 are
larger than the radius of the exterior, vertical surface
of the abutment surface 150.
The abutment surface 150 is defined by a
cylindrical arc surface which is preferably positioned
symmetrically relative to the web ends 102 so that it
projects outwardly from the cylindrical surface 158 into
the shoulder 136. In the preferred illustrated
embodiment, the abutment surface 150, at the centerline
137 of the hinge structure 80, may be characterized as
extending both (1) upwardly to an elevation above the
base shoulder surface 86, and (2) downwardly along a
vertical line to the shoulder 136 slightly below the
first film hinge 121.
The ledge 162 at the top of the abutment
surface 150 is recessed below the upper surface of the
base deck 56. The elevation of the abutment ledge 162
is established so that when the lid 70 is closed, the
lid shoulder surface 136A (FIGS. 7 and 10) will not
. 20 interfere with the abutment surface ledge 162.
The abutment surface 150 establishes a
vertically oriented abutment beyond which the hinge web
100 cannot move when the lid 70 is closed and opened.
The abutment surface 150 controls the position of the
hinge structure web 100 upon the closing and opening of
the lid 70. Preferably, the abutment surface 150 has a
vertical height, at the location along the center of the
hinge structure 80 (on the centerline 137 of the centers
of the closure base 50 and lid 70), which is at or above
the second film hinge 122 when the lid 70 is fully '
closed. In other words, at the longitudinal center of
the hinge structure 80 (on centerline 137), the abutment '
surface 150 extends upwardly above hinge 121 for a
distance that is greater than the shortest distance
between the film hinges 121 and 122.
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Upon the closing or opening of the lid 70, the
hinge structure web 100 engages the abutment surface 150
so that the position of the web 100 is controlled.
FIGS. 19 and 20 show how the web 100 bows inwardly
toward and against the abutment surface 150 when the lid
70 is partially closed. The abutment surface 150 should
preferably extend adjacent the web central portion 100
from the first film hinge 121 toward the second film
hinge 122 (when the lid is closed) more than one-half
l0 the shortest distance between the film hinges (as
measured at the centerline 137 between'the web ends
102). However, according to one aspect of the present
invention, the abutment surface 150 at the centerline
137 of the hinge structure 80 preferably extends all the
way to, and slightly beyond, the film hinge 122 when the
lid 70 is closed, and this is presently believed to
provide the most accurate control.
The radial extent of the projecting abutment
surface 150 can be easily varied during manufacturing
according to the hinge characteristics that are desired
for a particular application. If the abutment surface
150 projects outwardly a considerable amount, the hinge
structure web 100 contacts the abutment surface 150
earlier during the closing process. If the abutment
surface projection is less, the hinge structure web 100
would contact the abutment surface 150 later in the
closing process, or only when the lid is substantially
100 percent closed.
When the abutment surface 150 projects further
. 30 outwardly, the biasing action of the hinge structure 80
can be made greater to provide an opening and closing
. action with more "snap" or force. When the projection
of the abutment surface 150 is reduced, the biasing
force can be made less, and the opening and closing
action of the closure will be "softer." Further, when
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the abutment surface 150 projects further outwardly, the
full open position of the lid defines a greater opening
angle relative to the closure base than if the abutment
surface 150 projects outwardly a lesser amount.
In a presently contemplated commercial
embodiment, the radius of the abutment surface 150 is
0.553 inch and the diameter of the cylindrical surface
3.58 from which it projects is about 1.320 inch. The
height of the abutment surface 150 (at the ledge surface
162), is 0.03 inch from the molding parting plane 177
(FIG. 7) defined by the inner surface of the hinge web
100 when the lid is in the as-molded, fully opened
position. In particular, in FIG. 7, the 0.03 inch
dimension would correspond to dimension H. In contrast,
in the contemplated commercial embodiment, when the lid
70 is in the closed position, the lowest part of the
second film hinge 122 (at the centerline 137 between the
hinge web ends 102) would be 0.005 inch lower than the
abutment surface ledge 162. Thus, the abutment surface
150 extends upward slightly beyond the lowest point of
the lid film hinge 122 when the lid 70 is closed.
Generally, in a presently contemplated
commercial embodiment, it is desired to provide a hinge
structure 80 in which there is substantially no strain
in the hinge structure 80 when the lid 70 is in the
fully closed position. This minimizes the tendency of
the hinge structure 80 to loose its snap-action biasing
capability when the lid 70 is maintained closed for long
periods of time in the fully closed position.
In alternate designs wherein the hinge _
structure 80 would have some amount of strain when the
lid 70 is a.n the fully closed position, the strain .
could, over time, result in some creep of the closure
material and subsequent relaxation. This would reduce
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the amount of biasing force that the hinge structure
would exert during opening and closing of the lid.
The opening and closing action of the closure
incorporating the novel hinge structure of the present
S invention.is illustrated in FIGS. 11-18 and 19-21. FIG.
11 is a top plan view of the closure in the fully open,
as-molded condition. FIGS. 12-18 illustrate sequential
closing positions with FIGS. 17 and 18 showing the fully
closed position.
With reference to FIG. 11, the view line A-A
represents the section as taken in FIG. 12, and the view
line B-B represents the section as taken in FIG. 14.
FIGS. 13, 15, 16 and 17 correspond to the same section
A-A as FIG. 12, but FIGS. 13, 15, 16 and 17 show the lid
in positions moved away from the full open position that
is illustrated in FIGS. 11 and 12. FIG. 17 shows the
closure fully closed. FIG. 18 is an enlarged, rear
elevational view of the closed closure shown in FIG. 17.
FIGS. 19 and 20 are enlarged views taken along the plane
B-B in FIG. 11, but FIGS. 19 and 20 show intermediate
positions of the lid that lie between the two lid
positions illustrated in FIGS» 15 and 16. FIG. 21 is an
enlarged view taken along the plane B-B in FIG. 11, but
FIG. 21 shows the closure closed.
As the closure lid 70 is closed or opened
(relative to the base 50 which is assumed to be held
stationary), the lid 70 moves about two axes 201 and 202
(FIG. 11) which are parallel. The axis 201 is tangent
to the film hinge 121, and the axis 202 is tangent to
the film hinge 122.
With reference to FIG. 12, it is seen that a
transverse cross-section through the web 100 has a
substantially linear configuration when the lid 70 is in
the as-molded, fully open position. The angle between
the web 100 and the closure base 50 is designated by the
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a, and the angle between the web 100 and the closure lid
70 is designated by the angle (3. In the fully open
position, which corresponds to the as-molded condition,
the angle a and angle ~i are substantially equal.
when the fully open closure 40 is manipulated
to a closed condition, the closure base 50 (which is
typically attached to the container) is usually held in
a generally fixed orientation (by virtue of its mounting
to the container) while a closing force is applied to
the lid 70. As the lid 70 moves to the closed position,
the lid 70 and the web 100 move (counter-clockwise as
viewed in FIGS. 12-17)--but not in a fixed relationship
relative to the closure base 50.
As seen in FIG. 14, the lid 70 initially
pivots about the lid axis 202 through a greater angle ~i
compared to the movement of the web 100 about the base
axis 201 through a lesser angle a. Through much of the
closing range (from full open to more than 150° closed
as shown in FIGS. 12-16), the pivoting movement of the
lid 70 is greater about the web 100 than is the web
pivoting movement about the closure base 50.
Ultimately, however, at the closed condition (180° as
shown in FIG. 17), the lid/web angle a and the web/base
angle (3 become equal as shown in FIG. 1?. Thus, as the
lid 70 reaches the full closed position (FIG. 17), the
rate of angular displacement through the angle a at the
web/base film hinge 121 becomes greater than the rate of
angular displacement through the angle ,(3 at the web/lid
film hinge 122.
It will be appreciated that when the closure
base 50 is held stationary while the lid 70 a.s opened or
closed, the web/lid axis 202 moves through space ,
relative to the web/base axis 201. If both the lid 70
and base 50 are permitted to move during closing or
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opening, then each axis 201 and 202 can move through
space.
As the hinge structure 80 is moved from the
opened to the closed position, and vice versa, the
changes in the distance between the film hinges 121 and
122 near the ends 102 relative to the smaller changes in
the distance between the film hinges 121 and 122 at the
centerline 137 create a significant tension force or
"stretch" at the outer most ends 102. This causes the
hinge structure 80 to be unstable in any position
between the full open and full closed positions. This
results in the hinge structure 80 having an inherent
bias (when the lid is between the full open and full
closed positions). This urges the hinge structure 80 to
assume one of the two bistable positions (either full
open or full closed).
The stretch or tension in the hinge structure
80 serves to create a temporary deformation within the
hinge structure that is sufficient to move the lid 70
automatically toward the closed position or toward the
open position when it is released from any position
between the full open and full closed positions. The
lid will automatically move to the full closed position
if it is released while it is initially closer to the
full closed position. On the other hand, the lid will
automatically move to the full open position if the lid
is released from an initial position which is closer to
the full open position.
The hinge structure 80 of the present
. 30 invention may be incorporated in a variety of closures.
Another type of closure in which the hinge structure may
be used is illustrated in FIG. 22 wherein the closure is
designated generally by the reference numeral 400. The
closure 400 includes a closure base 450 and a closure
lid 470. A hinge structure 480 connects the base 450 to
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the lid 470. The hinge structure 480 is substantially
identical to the hinge structure 80 described above for
the first embodiment illustrated in FIGS. 1-18.
It will be appreciated that the full open
orientation of the closure illustrated in all of the
figures (except FIGS. 13-21) corresponds to the initial,
as-molded position. This as-molded position preferably
has the base and lid opened 180°. Once the lid is first
closed and the lid is thereafter opened and maintained
free of any exterior forces, the hinge structure will
typically maintain the lid in an open position which has
an opening angle somewhat less than the substantially
180° opening angle of the original, as-molded, open
orientation.
It is seen that the present invention thus
provides a closure which has a lid that operates with a
snap-action motion while moving to and from a closed
position. The hinge structure can be controlled upon
closing and opening by the abutment surface. The hinge
structure can be substantially strain-free in the fully
closed position.
The hinge structure protrudes minimally from
the rear of the closure when the closure lid is in the
closed position. This is compatible with high speed
closure applying machinery employed in conventional
container product filling lines. This permits the
closure to be used with containers processed at high
line speeds.
It will be appreciated that the closure of the
present invention provides a system for covering an -
opening to a container with a closure having a base lid
connected by a multiple axis bistable hinge structure.
The hinge structure includes a web and an engaging
abutment surface which can be designed to provide a
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small or large biasing force and a small or large lid
opening angle.
It will also be appreciated that the closure
of the present invention may be provided with a variety
of dispensing passage structures.
Further, the closure 40 need not be molded as
a unitary article. The hinge structure could be molded
as a separate element, and the lid and base could also
be molded as separate pieces. The separate hinge
structure could then be attached (e. g., by welding,
adhesive, mechanical snap-fit, etc.) to the lid and
base. The abutment surface could be molded as part of
the separate hinge structure element or it could be
molded as part of the lid or base. However, if the
abutment surface is molded as part of the lid or base
while the web and film hinges are molded together as an
element separate from the lid and base, then the
abutment surface may nevertheless still. be characterized
as being a functional, but separate, part of the novel
hinge structure per se. Further, the web could be
provided with slots, apertures, or decreased thickness
regions.
Also, the abutment surface (e. g., 150 in FIGS.
6 and 8) need not be a single, continuous surface. For
example, two slightly separated projecting surfaces
could be employed on either side of the closure
centerline 137 (FIG. 6).
It will be readily observed from the foregoing
detailed description of the invention and from the
illustrations thereof that numerous other variations and
modifications may be effected without departing from the
true spirit and scope of the novel concepts or
principles of this invention.
