U.S. patent application number 12/625859 was filed with the patent office on 2010-05-27 for lightweight child-resistant closure.
This patent application is currently assigned to Stull Technologies, Inc.. Invention is credited to Robert T. Auer, Lino Gabriel Ferri, Jason W. Stull.
Application Number | 20100126996 12/625859 |
Document ID | / |
Family ID | 42195276 |
Filed Date | 2010-05-27 |
United States Patent
Application |
20100126996 |
Kind Code |
A1 |
Ferri; Lino Gabriel ; et
al. |
May 27, 2010 |
Lightweight Child-Resistant Closure
Abstract
A child-resistant container closure includes a base cap having a
plurality of upwardly extending teeth and one or more ramps
protruding radially outwardly from a skirt, and a cover cap having
a plurality of downwardly extending teeth adapted for engagement
with the teeth of the base cap and one or more ramps protruding
radially inwardly from a skirt, the cover cap ramps being adapted
for engagement with the base cap ramps, and springs urging the
cover cap apart from the base cap for enabling selective engagement
between the base cap teeth and the cover cap teeth.
Inventors: |
Ferri; Lino Gabriel;
(Middletown, NJ) ; Stull; Jason W.; (Morristown,
NJ) ; Auer; Robert T.; (East Stroudsburg,
PA) |
Correspondence
Address: |
DRINKER BIDDLE & REATH;ATTN: INTELLECTUAL PROPERTY GROUP
ONE LOGAN SQUARE, SUITE 2000
PHILADELPHIA
PA
19103-6996
US
|
Assignee: |
Stull Technologies, Inc.
|
Family ID: |
42195276 |
Appl. No.: |
12/625859 |
Filed: |
November 25, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61200148 |
Nov 25, 2008 |
|
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|
Current U.S.
Class: |
220/281 |
Current CPC
Class: |
B65D 2215/02 20130101;
B65D 2251/01 20130101; B65D 50/041 20130101 |
Class at
Publication: |
220/281 |
International
Class: |
B65D 43/04 20060101
B65D043/04 |
Claims
1. A child-resistant container closure comprising: a base cap
having a top and a skirt depending downwardly from the top, the
base cap including a plurality of upwardly extending teeth, the
skirt including internal threads for engaging a neck of the
container, a bottom end, and one or more ramps protruding radially
outwardly from the skirt; a cover cap having a top and a skirt
depending downwardly from the top, the cover cap including a
plurality of downwardly extending teeth adapted for engagement with
the upwardly extending teeth of the base cap, the skirt having a
plurality of interspersed vertical legs each spaced apart from
adjacent legs by vertical openings, the legs being joined by a
support ring, the skirt including one or more ramps protruding
radially inwardly from the legs, the ramps being adapted for
asymmetric engagement with the outwardly protruding ramps of the
base cap skirt; and one or more springs for enabling selective
engagement between the upwardly extending teeth of the base cap and
the downwardly extending teeth of the cover cap; wherein in a rest
state the springs cause the base cap top and the cover cap top to
be separated by an at-rest distance such that the cover cap is
rotatable separately from the base cap without the respective teeth
engaging; wherein in an actuated state in which the cover cap is
displaced toward the base cap, the springs deflect to allow the
distance between the cover cap top and the base cap top to decrease
to an actuated distance to enable the respective teeth to engage
such that the rotation of the cover cap causes the base cap to
rotate along with the cover cap; wherein, in the rest state, when
the cover cap is rotated in a first direction, the cover cap ramps
positively engage the base cap ramps to cause the base cap to
rotate along with the cover cap in the first direction; and
wherein, in the rest state, when the cover cap is rotated in a
second direction, the cover cap ramps slide over the base cap ramps
causing an audible clicking sound as a closing face of each of the
cover cap ramps releases from a closing face of each of the
corresponding base cap ramps.
2. The closure of claim 1, the springs protrude downwardly from the
top of the cover cap.
3. The closure of claim 1, the springs comprising a plurality of
spaced apart spring members arranged in a generally circular
pattern protruding downwardly from the top of the cover cap.
4. The closure of claim 3, further comprising an annular ridge
protruding upwardly from the top of the base cap, the ridge
engaging the spring members for centering the cover cap on the base
cap, the ridge having a shaped surface for guiding the flexure of
the springs in the actuated state.
5. The closure of claim 3, wherein a base end of each of the spring
members is recessed into the cover cap top to provide a spring
length that is greater than the at-rest distance between the top of
the cover cap and the top of the base cap.
6. The closure of claim 3, wherein the spring members are at least
partially tapered so as to be thicker at a base to thinner at a
tip.
7. The closure of claim 7, wherein the tip of the spring members is
tapered on one side to facilitate initial bending of the spring
member.
8. The closure of claim 1, the springs comprising: a plurality of
spaced apart spring members arranged in a generally circular
pattern protruding upwardly from the top of the base cap.
9. The closure of claim 8, further comprising an annular ridge
protruding downwardly from the top of the cover cap, the ridge
engaging the spring members for centering the cover cap on the base
cap, the ridge having a shaped surface for guiding the flexure of
the springs in the actuated state.
10. The closure of claim 1, each of the base cap ramps having an
opening face opposite the closing face, the opening face and the
closing face slanting in the same direction with respect to a base
cap radius; and each of the cover cap ramps having an opening face
opposite the closing face, the opening face and the closing face
slanting in the same direction with respect to a cover cap radius;
wherein the engagement of the respective slanted closing faces
provides a positive engagement between the respective ramps for
turning the base cap when the cover cap is rotated in the first
direction; and wherein the engagement of the respective slanted
opening faces enables the ramps to slide over one another, the
slanted closing faces enhancing the audibility of the sound emitted
as the sliding engagement releases.
11. The closure of claim 1, the vertical legs in the cover cap
skirt have flexibility to allow the cover cap ramps and the base
cap ramps to slidably engage and release from one another when the
cover cap is rotated in the second direction but have rigidity to
enable the respective ramps to positively engage the base cap ramps
to cause the base cap to rotate along with the cover cap in the
first direction.
12. The closure o f claim 1, the vertical openings in the cover cap
being small enough to prevent a child's fingers from accessing and
turning the base cap independently from the cover cap, and being
configured to permit the audible clicking sound to emit from the
closure.
13. The closure o f claim 1, the support ring of the cover cap
including a rim which engages with the bottom face of the base cap
to inhibit removal of the cover cap from the base cap.
14. The closure o f claim 1, wherein one or the other of the cover
cap teeth and the base cap teeth is shaped to provide for greater
engagement force in the first direction than in the second
direction when the closure is in the actuated state.
15. A child-resistant container closure comprising: a base cap
having a top and a skirt depending downwardly from the top, the
base cap including a plurality of upwardly extending teeth, the
skirt including internal threads for engaging a neck of the
container, a bottom end, and one or more ramps protruding radially
outwardly from the skirt; a cover cap having a top and a skirt
depending downwardly from the top, the cover cap including a
plurality of downwardly extending teeth adapted for engagement with
the upwardly extending teeth of the base cap top, the skirt
including one or more ramps protruding radially inwardly from the
legs, the ramps being adapted for asymmetric engagement with the
outwardly protruding ramps of the base cap skirt, the skirt having
a support ring protruding radially inwardly from the cover cap
skirt to engage with a ridge protruding radially outwardly from the
bottom end of the base cap skirt to inhibit removal of the cover
cap from the base cap; and a plurality of spaced apart springs
arranged in a generally circular pattern protruding downwardly from
the top of the cover cap and an annular ridge protruding upwardly
from the top of the base cap, the ridge engaging the springs for
centering the cover cap on the base cap, the ridge having a shaped
surface for guiding the flexure of the springs for enabling
selective engagement between the upwardly extending teeth of the
base cap and the downwardly extending teeth of the cover cap;
wherein in a rest state the springs cause the base cap top and the
cover cap top to be separated by an at-rest distance such that the
cover cap is rotatable separately from the base cap without the
respective teeth engaging; wherein in an actuated state in which
the cover cap is displaced toward the base cap, the spring deflect
to allow the distance between the cover cap top and the base cap
top to decrease to an actuated distance to enable the respective
teeth to engage such that the rotation of the cover cap causes the
base cap to rotate along with the cover cap; wherein, in the rest
state, when the cover cap is rotated in a first direction, the
cover cap ramps positively engage the base cap ramps to cause the
base cap to rotate along with the cover cap in the first direction;
and wherein, in the rest state, when the cover cap is rotated in a
second direction, the cover cap ramps slide over the base cap ramps
causing an audible clicking sound as a closing face of each of the
cover cap ramps releases from a closing face of each of the
corresponding base cap ramps.
16. The closure of claim 15, wherein a base end of each of the
spring members is recessed into the cover cap top to provide a
spring length that is greater than the at-rest distance between the
top of the cover cap and the top of the base cap.
17. The closure o f claim 15, each of the base cap ramps having an
opening face opposite the closing face, the opening face and the
closing face slanting in the same direction with respect to a base
cap radius; and each of the cover cap ramps having an opening face
opposite the closing face, the opening face and the closing face
slanting in the same direction with respect to a cover cap radius;
wherein the engagement of the respective slanted closing faces
provides a positive engagement between the respective ramps for
turning the base cap when the cover cap is rotated in the first
direction; and wherein the engagement of the respective slanted
opening faces enables the ramps to slide over one another, the
slanted closing faces enhancing the audibility of the sound emitted
as the sliding engagement releases.
18. The closure of claim 15, the cover cap skirt having a plurality
of interspersed vertical legs each spaced apart from adjacent legs
by vertical openings, the legs being joined by the support ring,
the vertical openings in the cover cap being small enough to
prevent a child's fingers from accessing and turning the base cap
independently from the cover cap, and being configured to permit
the audible clicking sound to emit from the closure.
19. The closure o f claim 15, wherein one or the other of the cover
cap teeth and the base cap teeth is shaped to provide for greater
engagement force in the first direction than in the second
direction when the closure is in the actuated state.
Description
RELATED APPLICATION
[0001] This application is claims priority from U.S. Provisional
Application No. 61/200,148, filed Nov. 25, 2008, which is
incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The application relates to a lightweight container closure
or cap, and in particular to a container closure having a
child-resistant safety feature to inhibit opening of the container
by a child.
BACKGROUND
[0003] Child-resistant container closures are known in the art.
Such closures typically have a nested two-cap construction,
including a base cap for sealing a container opening and a cover
cap that captures the base cap. The base cap threads onto a neck of
the container about the opening. Cooperating features disposed on
an inner portion of the cover cap and an outer portion of the base
cap enable selective engagement between the base cap and the cover
cap, such that a single rotational action is sufficient to install
the closure onto the container while a combined rotational and
pushing and/or squeezing action is required to remove the closure
from the container. In practice, when the cover cap is rotated in a
first direction so as to thread the base cap onto the container
neck, the cover cap and the base cap reliably engage and rotate in
tandem, but when the cover cap is rotated in second a direction so
as to unthread the base cap from the container neck, the cover cap
must be further manipulated (e.g., by pushing downward on the cover
cap or squeezing a portion of the cover cap while rotating) to
cause the base cap to rotate in tandem with the cover cap. If the
cover cap is rotated in the second direction without further
manipulating the cover cap, the closure may emit a clicking sound
to indicate a failed attempt to open the closure. However, in many
existing closures, the clicking sound is only faintly audible.
SUMMARY
[0004] In one embodiment, a child-resistant container closure
includes a base cap, a cover cap, and one or more springs or
resilient members. The base cap has a top and a skirt depending
downwardly from the top, the base cap including a plurality of
upwardly extending teeth, the skirt including internal threads for
engaging a neck of the container, a bottom end, and one or more
ramps protruding radially outwardly from the skirt. The cover cap
has a top and a skirt depending downwardly from the top, the cover
cap including a plurality of downwardly extending teeth adapted for
engagement with the upwardly extending teeth of the base cap top.
The skirt has a plurality of interspersed vertical legs each spaced
apart from adjacent legs by vertical openings, the legs being
joined by a support ring, the skirt including one or more ramps
protruding radially inwardly from the legs. The ramps are adapted
for asymmetric engagement with the outwardly protruding ramps of
the base cap skirt. The springs enable selective engagement between
the base cap upwardly extending teeth and the cover cap downwardly
extending teeth. In a rest or non-engaged state the springs cause
the base cap top and the cover cap top to be separated by an
at-rest distance such that the cover cap is rotatable separately
from the base cap without the respective teeth engaging (i.e., the
teeth are not engaged). In an actuated state in which the cover cap
is displaced toward the base cap, the springs deflect so as to
allow the distance between the cover cap top and the base cap top
to decrease to an actuated distance to enable the respective teeth
to engage such that the rotation of the cover cap causes the base
cap to rotate along with the cover cap. In the rest state, when the
cover cap is rotated in a first direction, the cover cap ramps
positively engage the base cap ramps to cause the base cap to
rotate along with the cover cap in the first direction. In the rest
state, when the cover cap is rotated in a second direction, the
cover cap ramps slide over the base cap ramps causing an audible
clicking sound as a closing face of each of the cover cap ramps
releases from a closing face of each of the corresponding base cap
ramps.
[0005] In another embodiment, a child-resistant container closure
includes a base cap, a cover cap, and a plurality of springs. The
base cap has a top and a skirt depending downwardly from the top,
the base cap including a plurality of upwardly extending teeth, the
skirt including internal threads for engaging a neck of the
container, a bottom end, and one or more ramps protruding radially
outwardly from the skirt. The cover cap has a top and a skirt
depending downwardly from the top, the cover cap including a
plurality of downwardly extending teeth adapted for engagement with
the upwardly extending teeth of the base cap top, the skirt having
a support ring at a bottom end thereof. The skirt includes one or
more ramps protruding radially inwardly from the legs, the ramps
being adapted for asymmetric engagement with the outwardly
protruding ramps of the base cap skirt. The support ring protrudes
radially inwardly from the cover cap skirt to engage with a ridge
protruding radially outwardly from the bottom end of the base cap
skirt to inhibit removal of the cover cap from the base cap. The
springs are spaced apart and are arranged in a generally circular
pattern protruding downwardly from the top of the cover cap and an
annular ridge protrudes upwardly from the top of the base cap, the
ridge engaging the springs for centering the cover cap on the base
cap, the ridge having a shaped surface for guiding the flexure of
the springs for enabling selective engagement between the base cap
upwardly extending teeth and the cover cap downwardly extending
teeth. In a rest state, the springs cause the base cap top and the
cover cap top to be separated by an at-rest distance such that the
cover cap is rotatable separately from the base cap without the
respective teeth engaging. In an actuated state in which the cover
cap is displaced toward the base cap, the springs deflect so as to
allow the distance between the cover cap top and the base cap top
to decrease to an actuated distance to enable the respective teeth
to engage such that the rotation of the cover cap causes the base
cap to rotate along with the cover cap. In the rest state, when the
cover cap is rotated in a first direction, the cover cap ramps
positively engage the base cap ramps to cause the base cap to
rotate along with the cover cap in the first direction. In the rest
state, when the cover cap is rotated in a second direction, the
cover cap ramps slide over the base cap ramps causing an audible
clicking sound as a closing face of each of the cover cap ramps
releases from a closing face of each of the corresponding base cap
ramps.
[0006] Other objects, aspects and advantages of the present
invention will become apparent to those skilled in the art upon
reading the following detailed description, when considered in
conjunction with the appended claims and the accompanying drawings
briefly described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The above and other aspects, features and advantages of the
present invention will be more apparent from the following more
particular description thereof, presented in conjunction with the
following drawings wherein:
[0008] FIG. 1 is a top perspective view of a closure showing a base
cap captured within a cover cap.
[0009] FIG. 2 is a bottom perspective view of the cover cap of FIG.
1.
[0010] FIG. 3 is a bottom plan view of the cover cap of FIG. 2.
[0011] FIG. 4 is a top perspective view of the base cap of FIG.
1.
[0012] FIG. 5 is a top plan view of the base cap of FIG. 4.
[0013] FIG. 6 is a side cross-sectional view of the closure of FIG.
1.
DETAILED DESCRIPTION
[0014] Referring to FIGS. 1 and 6, an embodiment of a
child-resistant container closure 10 is depicted. The closure 10 is
a two-piece device including a cover cap 100 and a base cap 200.
The base cap 200 is designed to seal a container opening by
threading onto a neck of the container. The cover cap 100 is
designed to snap around and capture the base cap 200, as depicted
in FIGS. 1 and 6, and as is described in detail below.
[0015] With particular reference to FIGS. 2 and 3, the cover cap
100 includes a top 110 and a skirt 120 depending downwardly from a
periphery of the top 110. The skirt 120 extends from a top end
adjoining the top 110 to a bottom end 126. The skirt 120 has a
plurality of interspersed vertical legs 122 and vertical cut-outs
or openings 124. The legs 122 and the openings 124 alternate
preferably in a regular pattern and the legs 122 are joined
together at a bottom end 126 of the skirt 120 by a support ring
128. The support ring 128 provides rigidity to the skirt 120 while
the openings 124 enable the skirt 120 to be lighter in weight and
to use less material than a conventional solid skirt. Among other
benefits, the interspersed legs 122 and slots 124 provide a good
gripping surface for a user, particularly for a user with
arthritis, advanced age, or other condition that limits gripping
strength.
[0016] With particular reference to FIGS. 4 and 5, the base cap 200
includes a top 210 and a skirt 220 depending downwardly from a
periphery of the top 210. The skirt 220 extends from a top end
adjoining the top 210 to a bottom end 224. Internal threads 222
protrude inwardly from the skirt 220 for engagement with a
container neck. The base cap 200 has an outer diameter and the
cover cap 100 has an inner diameter, the outer diameter of the base
cap 200 being sufficiently smaller than the inner diameter of the
cover cap 100 to create an annular gap 300, as shown in FIG. 6.
Accordingly, if there were no outward protrusions from the base cap
skirt 220 and no inward protrusion from the cover cap skirt 120,
the gap 300 would permit the cover cap 100 to rotate freely about
the base cap 200 without interference or contact with the base cap
200.
[0017] To prevent the cover cap top 110 from resting in direct
contact with the base cap top 210, one or more springs or resilient
members 150 are provided to maintain the top 110 of the cover cap
100 spaced apart from the top 210 of the base cap 200 by a distance
310 between the cover cap top 110 and the base cap top 210. In a
rest or non-engaged state, when the cover cap 100 is not actuated
or depressed toward the base cap 200, the springs 150 establish an
at-rest distance. In an actuated or engaged state, when a user
applies downward force to displace the cover cap 100 toward the
base cap 200, the springs 150 establish an actuated distance that
is less than the at-rest distance. When the downward force is
removed, the springs 150 cause the cover cap 100 to move away from
the base cap 200 thus restoring the distance from the actuated
distance to the at-rest distance.
[0018] In the depicted embodiment, the springs 150 comprise a
plurality of individual spring members 152 extending downwardly
from the cover cap top 110. The spring members 152 are spaced apart
in a substantially circular or circumferential pattern and have a
length approximately equal to or greater than the at-rest distance
to be maintained between the cover cap top 110 and the base cap top
210. A raised annular ridge 214 protrudes upwardly from the base
cap top 210. As shown, the diameter of the annular ridge 214 is
slightly less than the diameter of the circular pattern formed by
tips 158 of the springs 150, so that the interaction between the
springs 150 and the ridge 214, as discussed below, causes the cover
cap 100 to be in a substantially centered disposition with respect
to the base cap 200. However, it is understood that the cover cap
100 could be similarly centered on the base cap 200 if the annular
ridge 214 were to have a diameter slightly larger than the diameter
of the circular pattern of the springs 150. It is also contemplated
that, instead of a ridge, a channel could be formed on the base cap
to provide centering for the springs 150.
[0019] The annular ridge 124 has a shaped surface 216 for guiding
the flexure of the springs 150 as the closure 10 moves from the
rest state to the actuated state. In particular, the shaped surface
216 preferably has a concave curvature where the ridge 214 joins
the top 210 to direct the flexing of the spring members 152 as the
distance between the top 110 and the top 210 becomes smaller
relative to the length of the spring members 152.
[0020] In one embodiment, as most clearly shown in FIGS. 2, 3, and
6, a groove 154 is provided on one or both sides of each spring
member 152 to enhance the ability of the spring member 152 to flex
at the junction of the spring member 152 and the top 110 without
fracturing. The groove 154 results in a longer length of spring
member 152, thus increasing the flexibility of the spring member
152. The spring members 152 can also be tapered from thicker at a
base where the spring members 152 attach to the top 110 to thinner
at a tip. As shown in FIG. 6, the tip preferably is curved, sloped,
or chamfered on one side to facilitate the initial bending of the
spring member 152 in one direction.
[0021] It is understood that the springs may alternatively comprise
a plurality of individual spring members 152 extending upwardly
from the base cap top 210 cooperating with an annular ridge 214
protruding downwardly from of a channel disposed in the cover cap
top 110.
[0022] As shown in FIGS. 2, 3, and 6, a plurality of teeth 130
extend downwardly preferably from the top 110 of the cover cap 100.
The teeth 130 are circumferentially spaced apart at a regular
spacing distance. As shown in FIGS. 4, 5, and 6, a plurality of
teeth 230 extend upwardly preferably from the top 210 of the base
cap 200. The teeth 230 are circumferentially spaced apart at a
regular distance. The positions of the teeth 230 of the base cap
200 substantially correspond to the positions of the teeth 130 of
the cover cap 100 to enable engagement or meshing between the teeth
130, 230. The number of teeth 130 and the number of teeth 230 need
not be the same, but are preferably multiples of each other. As
shown in one embodiment, there are twelve teeth 130 and twelve
teeth 230, so that when the teeth are able to engage, the cover cap
100 can have a free play of no more than about 30 degrees (or
one-twelfth of a rotation) before engaging the base cap 200. Note
that even if only one of the sets of teeth has twelve teeth and the
other set of teeth has an even fraction of twelve teeth (e.g., two,
three, four, or six teeth), the same amount of free play would be
achieved, but the engagement force would be spread across less
pairs of meshing teeth 130, 230. Accordingly, the number of teeth
130 and the number of teeth 230 can be selected to achieve the
desired amount of free play between the cover cap 100 and the base
cap 200 and the required engagement force between the sets of teeth
130, 230.
[0023] As shown in FIGS. 4 and 5, the teeth 230 may be shaped with
an asymmetric bias (i.e., ramped), rising nearly perpendicularly
from the base cap top 210 at an engagement face 232 and having legs
234, 236 that taper to the base cap top 210 opposite the engagement
face 232. The asymmetry of the teeth 230 enables the teeth 230 to
engage the teeth 130 with a greater force in one direction of
rotation than in the opposite direction of rotation. In particular,
because the primary function of the teeth 130, 230 is to enable
removal of the closure 10 from the container but not necessarily to
enable installation of the closure 10 onto the container, the tooth
130 engages with the tapered legs 234, 236 of the tooth 130 when
the cover cap 100 is rotated in a first, installation or
tightening, direction (typically clockwise for right-handed threads
222) and with the engagement face 232 of the tooth 130 when the
cover cap 100 is rotated in a second, removal or loosening,
direction (typically counter-clockwise for right-handed threads
222). The asymmetric bias of the teeth 130 enables the teeth 130,
230 to interact with sufficient force to open the closure 10 when
the cover cap 100 is rotated in the second direction but prevents
accidental over-tightening of the closure 10 onto the container
when the cover cap 100 is rotated in the first direction. One
benefit of forming the teeth on the base as shown is that less
material is used while still providing a structural engagement
surface.
[0024] The teeth 130 and the teeth 230 have a combined height that
is at least slightly less than the at-rest distance between the top
110 and the top 210, such that when the cover cap 100 is not
actuated toward the base cap 200, the teeth 130, 230 cannot engage
with one another, and the cover cap 100 can be rotated freely, at
least in the second direction, without rotating the base cap
200.
[0025] As best illustrated in FIGS. 2, 3, and 6, the cover cap 100
further includes one or more cover cap ramps 140 protruding
radially inwardly from the skirt 120, and more specifically from a
corresponding one or more legs 122 of the skirt 120. The ramp 140
has a gently sloped opening or ramped face 142 and a more sharply
sloped closing or engagement face 144. In the depicted embodiment,
the opening face 142 slopes at an angle of about 20 degrees with
respect to the circumferential shape of the skirt 120. An effective
ramp 140 can include a opening face 142 sloping in the range of
about 5 degrees to about 45 degrees. An opening face slope of less
than about 5 degrees will likely cause the ramp 140 to be
excessively long and an opening face slope of greater than about 45
degrees will likely cause the rise to be too sharp for the closure
10 to operate as desired. The closing face 144 can be disposed
substantially perpendicularly to the skirt 120 or more preferably
can slope in either direction with respect to perpendicular. If the
closing face 144 slopes in the opposite direction to the opening
face 142, the slope should be limited to no more than about 10
degrees from perpendicular to achieve the desired operation of the
closure 10. As depicted, the closing face preferably slopes in the
same direction as the opening face 142. The slope of the closing
face 144 in this direction should be limited to no more than about
20 degrees from perpendicular to the skirt 120 to maintain the
required structural rigidity of the ramp 140 near its apex 146
where the faces 142, 144 join. By sloping the closing face 144 in
the same direction as the opening face 142, the ramp 140 can
interlock with a corresponding ramp 240 on the base cap 200. This
functions to draw the teeth together, thereby preventing the legs
22 from flexing away from the base cap 200 when rotational torque
is applied to the cover cap 100. Further, by maintaining a sharp
and rigid apex 146, the audible clicking sound created by the
release of the ramps 140 from corresponding ramps 240 on the base
cap 200 can be enhanced, as explained below.
[0026] As best illustrated in FIGS. 4, 5, and 6, the base cap 200
further includes one or more base cap ramps 240 protruding radially
outwardly from the skirt 220. The ramp 240 has a gently sloped
opening or ramped face 242 and a more sharply sloped closing or
engagement face 124. In the depicted embodiment, the opening face
242 slopes at an angle of about 20 degrees with respect to the
circumferential shape of the skirt 220. An effective ramp 240 can
include an opening face 242 sloping in the range of about 5 degrees
to about 45 degrees. The closing face 244 can be disposed
substantially perpendicularly to the skirt 220 or can slope in
either direction with respect to perpendicular. If the closing face
244 slopes in the opposite direction to the opening face 242, the
slope should be limited to no more than about 10 degrees from
perpendicular to achieve the desired operation of the closure 10.
As depicted, the closing face slopes in the same direction as the
opening face 242. The slope of the closing face 244 in this
direction should be limited to no more than about 20 degrees from
perpendicular to the skirt 220 to maintain the required structural
rigidity of the ramp 240 near its apex 246 where the faces 242, 244
join. By sloping the closing face 244 in the same direction as the
opening face 242, the ramp 240 can interlock with a corresponding
ramp 140 on the cover cap 100 to prevent the legs 22 from flexing
away from the base cap 200 when rotational torque is applied to the
cover cap 100, as discussed above. Further, by maintaining a sharp
and rigid apex 246, the audible clicking sound created by the
release of the ramps 240 from corresponding ramps 140 on the cover
cap 100 can be enhanced, as explained below.
[0027] The combined distance by which the ramps 140 protrude
inwardly from the cover cap skirt 120 and the ramps 240 protrude
outwardly from the base cap skirt 220 is at least large enough to
slightly exceed the annular gap 300 between the skirt 120 and the
skirt 220. Therefore, as the cover cap 100 is rotated in either
direction with respect to the base cap 200, the respective ramps
140, 240 necessarily interact.
[0028] When the cover cap 100 is rotated in the first or tightening
direction of rotation, the sharp closing face 244 of the ramp 240
comes into contact with the sharp closing face 144 of the ramp 140
and the ramps 140, 240 engage with each other in a manner that
strongly inhibits, but does not completely prevent, further
rotation of the cover cap 100 with respect to the base cap 200.
[0029] Therefore, as long as the threads 222 of the base cap 100
are not fully and tightly engaged with corresponding threads on the
container neck, further rotation of the cover cap 100 in the first
direction will cause the base cap 200 to rotate along with the
cover cap 100 in the first direction. Once the threads 222 of the
base cap 100 become fully engaged with the corresponding threads on
the container neck, the ramps 140, 240 remain engaged to tighten
the threaded engagement to secure the closure 10 on the container
sufficiently to prevent accidental or inadvertent loosening of the
closure 10. It is well within the knowledge of a typical user of
container closures 10 to estimate the amount of tightening that is
sufficient. If a user attempts to significantly over-tighten the
closure 10 onto the container, the legs 122 of the cover cap skirt
120 eventually flex enough to permit the closing faces 144 of the
ramps 140 to disengage from the closing faces 244 of the ramps 240
so that the cover cap 100 jumps or rotates with respect to the
based cap 200 until the next ramp-to-ramp (140-to-240) engagement,
indicating to the user that the closure 10 is at least sufficiently
tight.
[0030] When the cover cap 100 is not depressed such that the
springs 150 are in the rest state, and the cover cap 100 is rotated
in the first direction, the interaction between the ramps 140, 240
is the only mechanism that enables tightening of the base cap 200
onto the container. When the spring means 150 is in the actuated
state and the cover cap 100 is rotated in the first direction, the
interaction between the ramps 140, 240 may be supplemented by the
interaction between the teeth 130, 230; as described above, the
engagement between teeth 130, 230 in the first direction is also
preferably designed to automatically limit the amount of tightening
force that can be applied to tighten the closure 10 onto the
container 10, as a result of the tapered legs 234, 236.
[0031] When the cover cap 100 is rotated in the second or loosening
direction of rotation, the shallow opening face 242 of the ramp 240
comes into contact with the shallow opening face 142 of the ramp
140 and the ramps 140, 240 engages with each other in a manner that
provides a gentle and minimal frictional force between the ramps
140, 240, as the opening faces 142, 242 slidably engage with, and
slide over, each other. The frictional interaction between the
opening faces 142, 242 is insufficient to overcome the holding
force of a sufficiently tightened base cap 200. In other words,
when the base cap 200 is fully and sufficiently tightened onto the
container, the frictional interaction between the opening faces
142, 242 is not enough to loosen the base cap 200. Therefore, when
the threads 222 of the base cap 100 are fully engaged with the
corresponding threads on the container neck, the legs 122 of the
cover cap skirt 120 flex enough to permit the opening faces 142 of
the ramps 140 to slide completely over and release from the opening
faces 242 of the ramps 240.
[0032] When the release occurs, and the apex 146 releases from the
apex 246, an audible clicking sound is emitted, and the cover cap
100 jumps or rotates with respect to the base cap 200 until the
next ramp-to-ramp (140-to-240) engagement, during which the opening
faces 142 of the ramps 140 again slide completely over and release
from the opening faces 242 of the ramps 240, making the clicking
sound again, the process repeating as long as a user continues to
rotate the cover cap 100 in the second direction and the springs
150 are in the rest state. The audible clicking sound serves two
purposes. First, it reminds a user that the closure 10 is a
child-resistant cap and that a more complex pushing and rotating
action is required to open the closure 10. Second, it provides an
audible alert to an adult in the event a child is attempting to
open the closure 10. A particular advantage of the closure 10 is
that the openings 124 in the skirt 120 permit the clicking sound
made by the releasing of the ramps 140, 240 from each other to more
readily escape from within the cover cap 100, thereby making the
sound louder and more audible by a user or an adult responsible for
the safety of a child. Testing has shown an appreciable increase in
the audible sound caused by the openings 124 in the skirt 120.
[0033] As described, when the cover cap 100 is not depressed such
that the springs 150 are in the rest state, the base cap 200 is
tightened on the container neck, and the cover cap 100 is rotated
in the second direction, the interaction between the ramps 140, 240
serves only to create an audible sound. Therefore, to open the
closure 10, the springs 150 must be actuated to the actuated state
by depressing the cover cap 100 toward the base cap 200, to cause
engagement of the teeth 130, 230. When the cover cap 100 is
depressed such that the springs 150 are in the actuated state, and
the cover cap 100 is rotated in the second direction, the teeth
130, 230 engage and mesh as described above. In particular, the
engagement between the teeth 130 and the engagement faces 232 of
the teeth 230 provides sufficient engagement force to overcome the
tightening of the base cap threads 222 onto the container neck
threads so that the closure 10 can be loosened from the container
neck.
[0034] In the illustrated embodiment, the base cap skirt 220
includes six ramps 240 and the cover cap skirt 120 includes three
ramps 140. It is understood that the number of cover cap ramps 140
and the number of base cap ramps 240 need not be the same, and that
the number of ramps 140, 240 can be selected to achieve a
combination of a desired engagement force in the first direction of
rotation, a desired engagement force in the second direction of
rotation, and a level of audible clicking sound. For example, for a
relatively small closure 10, the combination of four cover cap
ramps 140 and one base cap ramp 240 may be adequate to enable
sufficient tightening of the closure 10 and to prevent unintended
opening of the closure 10. However, for a larger closure 10, it may
be necessary to have eight or more cover cap ramps 140 in
combination with four or more base cap ramps 240 to provide
sufficient tightening force while still not provide excessive
loosening force.
[0035] The cover cap 100 and the base cap 200 are held together to
form the closure 10, such that the cover cap 100 is rotatable with
respect to the base cap 200 but the cover cap 100 is not readily
removable from the base cap 200. Capturing the base cap 200 within
the cover cap 100 in this manner prevents a child from
circumventing the safety features of the closure 10 by simply
removing the cover cap 100 to directly rotate the base cap 200. In
the embodiment of the closure 10 as shown particularly in FIGS. 1
and 6, the cover cap support ring 128 protrudes radially inwardly
from the bottom end 126 of the skirt 120 to bridge the gap 300,
such that when the cover cap 100 is installed over the base cap
200, a rim of the support ring 128 is beneath the bottom end 224 of
the base cap skirt 220. Therefore, if a user or a child attempts to
lift the cover cap 100 off of the base cap 200, the rim will
contact the bottom end 224 of the base cap skirt 220 and prevent
removal of the cover cap 100. It is understood, however, that the
cover cap skirt 120 and the support ring 128, as well as the base
cap skirt 220, are sufficiently flexible that if a large enough
force and/or a skewed force is applied when attempting to lift the
cover cap 100, the cover cap 100 can be forcibly removed from the
base cap 200. To further inhibit the removal of the cover cap 100
from the base cap 200, the bottom end 224 of the base cap skirt 200
can also include a ridge 226 protruding outwardly therefrom for
engagement with the support ring 128.
[0036] As a further safety feature, the openings 124 in the cover
cap skirt 120 may be sized to be sufficiently small so as to
prevent a child's fingers from directly accessing and turning the
base cap 200 without having to rely on the engagement between the
cover cap 100 and the base cap 200 to open the closure 10.
[0037] Although specific embodiments have been described, the
skilled artisan will understand how various modifications may be
made within the scope of the present invention, which is defined by
the attached claims.
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