Information
-
Patent Grant
-
6206216
-
Patent Number
6,206,216
-
Date Filed
Monday, July 26, 199925 years ago
-
Date Issued
Tuesday, March 27, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 215 217
- 215 218
- 215 219
- 215 220
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International Classifications
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Abstract
A multiple-piece cap assembly which is child-resistant, yet which, because of radial contact between the caps, can be more easily opened by persons such as the elderly, arthritic, disabled and infirm adults. In an exemplary embodiment of the present invention, removal of the cap assembly requires two simultaneous motions such as, for example, turning the cap and pushing downward to engage lug and ramp projections on the caps. In this embodiment of the present invention, the two caps engage each other by a ramp and lug configuration in order to fasten and remove the cap assembly, wherein the lugs and ramps engage one another substantially by “line” contact and/or “surface-to-surface” contact. The cap of the present invention thus requires less force in at least one direction of the concurrent motions in order to remove the cap assembly, thus making the cap assembly child-resistant, yet senior-friendly.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates generally to child-resistant closures, and more particularly to child-resistant closures with multiple caps which engage by radial contact offering advantages over the prior art by enabling easier opening, yet which remain child-resistant.
2. Background of the Invention
Today, child-resistant closures are very important for the safety of children. As used herein, use of the term “child-resistant closure” is consistent with 16 CFR 1700 and refers generally to the inability of a younger child's or person with a younger child's strength and/or manual dexterity to open a closure 85% of the time within a given amount of time without a demonstration of how to open the closure, or 80% of the time with such a demonstration.
There are presently many different child-resistant closure designs. Of the most common closures, those which have proven to work well are caps which require two or more concurrent motions in order to open them. For example, one such design is the “push-and-turn” closure. Generally, such closures can only be opened by simultaneously pushing downward on the cap while turning it.
Examples of “push-and-turn” designs are disclosed in U.S. Pat. No. 4,319,690, issued to Stewart H. Birrell and Peter Hedgewick on Mar. 16, 1982, and U.S. Pat. No. 4,394,916, issued to Ned J. Smalley on Jul. 26, 1983. These patents describe a typical two-piece, ramp and lug design. Essentially the closure comprises an inner cap and an outer cap which are rotatably attached to one another. A plurality of lugs on one cap project towards a plurality of corresponding ramps on the opposite cap. Generally, the ramps and lugs engage each other when turned in a fastening direction such that the two caps turn in tandem.
However, when the cap is merely rotated in an “unfastening” direction, the lugs tend to slide over the ramps. The outer cap turns freely from the inner cap, and the inner cap remains fastened to the container. In order to open the cap, the outer cap must be pushed downward in order to counteract the tendency of the lugs to slide over the ramps while the cap is being turned.
These cap designs tend to work well because children lack the strength, cognitive ability, dexterity and/or motor skills to make the required motions simultaneously. The dual motion closures thus prove to be not readily openable by children, and therefore effectively achieve the goal of preventing children from opening the container on which the closure is attached.
However, though the many child-resistant closures are effective at preventing children from opening them, the closures have also proven to be very difficult for others lacking strength and/or manual dexterity skills, though not necessarily to the same extent of a child. For example, seniors and others suffering from arthritis, loss of strength and other similar infirmities and disabilities may find such closures difficult to open. In the following description, closures which present such difficulties (e.g., 10% or more of seniors cannot open the closure within a given time) will be referred to generally as “senior-resistant” while closures which can be opened by such will be referred to generally as “senior-friendly”.
Senior resistant closures are troublesome as quite often, seniors are the very persons in need of the contents (e.g., medication) sealed by the closure. However, because they may be arthritic or have a general lack of strength, coordination, dexterity, etc., seniors (and disabled or infirm) are not able to open the closure. In particular, though they may be able to make the simultaneous motions required to open the closure, the lugs typically engage the ramps through the range of contact at only one point or region of contact, away from the outer edge of the cap. This “point contact” coupled with the location of that point require that more torque and/or downward force be applied in order to remove the cap. Seniors often do not have sufficient strength or dexterity to both supply the extra torque required and push downward on the cap in order to remove the cap assembly. The closure thus becomes, in effect, senior-resistant as well as child-resistant.
Designers and manufacturers of child-resistant closures have long recognized the difficulty seniors have in accessing containers with child-resistant closures. However, no designs which overcome the effects of “point contact” have been developed, and similarly, no other designs which adequately prevent children from opening the closures, yet which allow seniors to open them have been developed.
For example, attempts to address such difficulties, so-called “arthritis caps”, have been developed. These caps are designed to be more easily opened by arthritics. However, the caps suffer from being more readily openable by children as well. This is generally because as the closures became easier for seniors to open, to some extent, it becomes easier for children to open the closures as well. Such a result is unacceptable as preventing children from opening the closures outweighs the desire for seniors to have the ability to open the closure. Thus, true child-resistant caps remain a necessity.
Accordingly, a child-resistant closure which overcomes the drawbacks of point contact, which children cannot remove, yet which seniors can more readily remove is therefore desirable.
SUMMARY OF THE INVENTION
The present invention provides a child-resistant, multiple-piece cap assembly which has substantially radial contact between the caps and allows seniors to more readily remove the assembly. In an exemplary embodiment of the present invention, rem oval of the cap assembly requires two simultaneous motions such as, while turning the cap, pushing downward to engage various projections on the caps. For example, in one embodiment the two caps engage each other by a ramp and lug configuration in order to fasten and remove the cap assembly, wherein the lugs and ramps engage one another substantially radially by “line” and/or “surface-to-surface” contact. The cap of this embodiment thus requires less force in at least one direction of the concurrent motions in order to remove the cap assembly, thereby leaving the cap assembly child-resistant, yet making it senior-friendly.
BRIEF DESCRIPTION OF THE DRAWINGS
Additional aspects of the present invention will become evident upon reviewing the non-limiting embodiments described in the specification and the claims taken in conjunction with the accompanying figures, wherein like numerals designate like elements, and:
FIG. 1
is a cross-sectional view of an inner cap retained in an outer cap of a child-resistant cap assembly;
FIG. 2
a
is a top view of an inner cap of a child-resistant cap assembly;
FIG. 2
b
is a cross-sectional side view of an inner cap of a child-resistant cap assembly;
FIG. 3
a
is a top view of a ramp of a child-resistant cap assembly;
FIG. 3
b
is a side view of a ramp of a child-resistant cap assembly;
FIG. 4
is an alternative embodiment of a ramp of a child-resistant cap assembly;
FIG. 5
a
is a bottom view of an outer cap of a child-resistant cap assembly;
FIG. 5
b
is a cross-sectional side view of an outer cap of a child-resistant cap assembly;
FIG. 6
a
is a top view of a lug of a child-resistant cap assembly;
FIG. 6
b
is a side view of a lug of a child-resistant cap assembly;
FIG. 7
is a side view of a lug engaging a ramp while fastening a child-resistant cap assembly;
FIG. 8
a
is a side view of a lug sliding over a ramp while attempting to unfasten a child-resistant cap assembly; and
FIG. 8
b
is a side view of a lug engaging a ramp while unfastening a child-resistant cap assembly.
DETAILED DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS
The following descriptions are of preferred exemplary embodiments only, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description merely provides a convenient illustration for implementing a preferred embodiment of the invention. For example, various changes may be made to the function and arrangement of elements described in the preferred embodiments without departing from the spirit and scope of the invention as set forth in the appended claims. In addition, while the following detailed description is directed to push-and-turn and ramp-and-lug child-resistant closures, the present invention is not limited to such designs and is similarly applicable to closures utilizing other means of “child-resistance”, and cap configurations such as those including more than two caps or those which employ “interlocking” child-resistant structures.
Further, though the following description of preferred embodiments of the present invention is directed to a child-resistant closure which senior citizens have less difficulty removing, yet which remain child-resistant, similarly, other adult cross-sections of society, such as the disabled, infirm or arthritic adults, will likewise be able to remove the closure.
Generally, in accordance with one embodiment of the present invention, a child-resistant closure is provided which is suitably comprised of a cap assembly and a mechanism or structure which makes the assembly child-resistant, yet which is substantially more senior-friendly than previously known caps.
For example, according to one aspect of this embodiment, the mechanism may suitably comprise a set of projections which allow engagement between caps of a multiple-piece cap assembly by substantially radial contact between those projections throughout the range of relative motion between the projections. However, one skilled in the art will realize that in various alternative embodiments, other mechanisms or structures which make a cap assembly suitably child-resistant can also provide substantial radial contact and may also allow the assembly to remain more senior-friendly, thereby still falling within the spirit and scope of the present invention.
Accordingly, with reference to
FIG. 1
, in accordance with an exemplary embodiment of the present invention, a child-resistant cap assembly
10
is suitably comprised of two caps, an inner cap
20
and an outer cap
30
. However, in accordance with various alternative embodiments, cap assembly
10
is not limited to two caps, and may instead be configured with only one cap, or alternatively, with one or more additional caps.
In the present exemplary embodiment, inner cap
20
and outer cap
30
are both formed from a plastic material such as polyvinyl chloride (PVC), though differing materials such as low or high density polyethylene, polypropylene, polystyrene, polyester teraphthalate (PET), nylon and the like may be similarly substituted. Further, according to various alternative aspects of the present invention, inner cap
20
and outer cap
30
may each suitably be formed from differing materials. For example, it may be desirable to form outer cap
30
from a more rigid material than inner cap
20
so that outer cap
30
is more easily gripped by the user or so that inner cap
20
has the ability to resiliently deform as desired when cap assembly
10
is used.
With reference to
FIG. 2
, inner cap
20
is suitably comprised of a first circular top
22
and a first annular extending side wall
24
. First side wall
24
is suitably configured to be threadably mounted on a container. However, according to various alternative aspects of the present invention, cap assembly
10
, inner cap
20
and/or first side wall
24
may be configured to mount on the container in a variety of alternative configurations.
In accordance with various aspects of the present invention, and with continuing reference to
FIG. 2
, inner cap
20
is suitably configured with at least one ramp
26
. In the present exemplary embodiment, inner cap
20
is configured with twelve ramps
26
. Ramps
26
are suitably located on a top surface
28
of inner cap
20
, though, according to various alternative aspects and embodiments of the present invention, ramps
26
may be located on another surface of inner cap
20
such as an outside surface
21
of first side wall
24
.
In accordance with one aspect of the present invention, ramps
26
are suitably configured annularly at evenly spaced intervals, in proximity to an outer edge
29
of first circular top
28
. However, according to various alternative aspects, ramps
26
may be situated in varying configurations such as, for example, proximate to a center
23
of first circular top
28
, at uneven intervals, staggered radially, or other similar configurations.
According to an exemplary embodiment of the present invention and as will be described in further detail below, ramps
26
are suitably configured such that outer cap
30
can engage inner cap
20
by radial contact in the form of “line” or “surface-to-surface contact” at substantially more points of relative rotation of inner cap
20
and outer cap
30
when unfastening cap assembly
10
than heretofore known. For example, with reference to
FIG. 3
, ramp
26
may be suitably configured with a first off drive surface
25
and a first on drive surface
27
.
In accordance with one aspect of a preferred embodiment of the present invention to obtain line contact, first off drive surface
25
is suitably configured as a first complex angle a. First complex angle α is suitably formed by at least two angles relative to top surface
28
and center
23
of inner cap
20
. According to the present aspect of the current embodiment, first complex angle α is formed by a first varying angle β and a second fixed angle δ. As described in further detail below, first varying angle β varies along first off drive surface
25
such that radial contact between ramp
26
and lug
36
is maintained throughout the range of relative motion between inner cap
20
and outer cap
30
.
With continuing reference to
FIG. 3
, first varying angle β is preferably formed as a varying acute angle with top surface
28
of inner cap
20
. That is, first varying angle β changes such that, as described below, as lug projection
36
moves over ramp
26
, lug
36
and ramp
26
remain in radial contact, i.e. first varying angle β changes as a function of distance across first off drive surface
25
.
Second angle δ is suitably formed such that any line horizontal to top surface
28
of inner cap
20
and which engages in radial contact with first off drive surface
25
will pass through a center line
41
of first circular top
28
, i.e., a radial line.
Now, still referring to
FIG. 3
, according to another aspect of a preferred embodiment of the present invention, first on drive surface
27
is suitably formed substantially vertically (perpendicular) relative to first circular top
22
. However, according to various alternative aspects with momentary reference to
FIG. 4
, first on drive surface
27
may be oriented at an angle relative to first circular top
22
such that, again as will be described in more detail below, first on drive surface
27
more readily facilitates the application of cap assembly
10
by engagement with outer cap
30
.
With reference now to
FIG. 5
, according to an exemplary embodiment of the present invention, outer cap
30
is suitably comprised of a second circular top
32
and a second annular sidewall
36
. In accordance with this embodiment, outer cap
30
is suitably configured to retain inner cap
20
such that outer cap
30
and inner cap
20
are freely rotatable relative to each other. For example, in accordance with a preferred embodiment of the present invention, inner cap
20
is suitably retained in outer cap
30
by a retaining mechanism
40
such as an annular lip formed on an inside surface
33
and proximate to a lower edge
38
of second sidewall
34
, though inner cap
20
may be retained in outer cap
30
by any other suitable retaining mechanism
40
. For example, inner cap
20
may be retained in outer cap
30
by structures such as, among others, skirts, webs, flaps and the like.
In addition, the location of retaining mechanism
40
may vary with alternative embodiments of the present invention, such as, for example, locating retaining mechanism
40
away from lower edge
38
or on a lower surface
39
of second circular top. Preferably, lip
40
suitably extends the entire circumference of second sidewall
36
. However, according to various alternative aspects of the present embodiment, lip
40
may extend only partially or in segments around the circumference of second sidewall
36
.
With continuing reference to
FIG. 5
, in accordance with an exemplary embodiment of the present invention, outer cap
30
is suitably configured with at least one lug
36
. Preferably, outer cap
30
is configured with the same number of lugs
36
as inner cap
20
has ramps
26
though any number or configuration of lugs
36
and projections may be suitable. Thus, in the present exemplary embodiment, as inner cap
20
has twelve ramps
26
, outer cap
30
is suitably configured with twelve lugs
36
. Additionally, lugs
36
are suitably located on lower surface
39
, though according to various aspects and alternative embodiments of the present invention, lugs
36
may be located on various other surfaces of outer cap
30
such as an inner surface
33
of second annular sidewall
34
.
In accordance with a preferred embodiment of the present invention, lugs
36
are suitably located to correspond and engage with ramps
26
. In this embodiment, ramps
26
are located annularly at evenly spaced intervals, in proximity to outer edge of first circular top
22
. Accordingly, lugs
36
should similarly be located as such to correspond to ramps
26
, i.e., annularly at evenly spaced intervals, in proximity to an outer edge
35
of second circular top
32
.
Referring now to
FIG. 6
, in a preferred embodiment of the present invention, lugs
36
are suitably configured with a second off drive surface
35
and a second on drive surface
37
. In the present exemplary embodiment, second sliding
35
surface of lugs
36
suitably corresponds to first off drive surface
25
of ramps
26
such that lug
36
and corresponding ramp
26
engage by line or surface-to-surface contact. That is, throughout the relative rotation of inner cap
20
and outer cap
30
, lug
36
remains in contact with ramp
26
, not by merely point contact, but by radial contact across ramp
26
. Similarly, second on drive surface
37
of lug
36
suitably corresponds to first on drive surface
27
of ramps
26
.
According to one aspect of the present invention, second off drive surface
35
suitably corresponds to first off drive surface
25
by being formed by a second complex angle α′. Second complex angle α′ is suitably formed by a third angle δ′ and a fourth angle β′. Third angle δ′ is substantially equivalent to second angle δ and fourth angle β′ substantially corresponds to first angle β such that radial contact is maintained between lug
36
and ramp
26
throughout the range of relative motion of lug
36
and ramp
26
. Accordingly, at any point of relative rotation across first off drive surface
25
and second off drive surface
35
between inner cap
20
and outer cap
30
, lugs
36
remain in line or surface to surface contact radially across ramp
26
rather than by merely point contact.
For example, in accordance with one aspect of this embodiment and with reference to
FIG. 7
, fourth angle β′ is suitably formed as an acute angle with respect to a bottom surface
39
of outer cap
30
such that second off drive surface
35
remains in surface-to-surface contact with first off drive surface
35
.
Now, with reference back to
FIG. 6
, in the illustrated embodiment, second on drive surface
37
is suitably formed substantially vertical relative to second circular top
32
. Again however, according to alternative embodiments of the present invention, as the angle of first on drive surface
27
varies, the angle of second on drive surface
37
should vary correspondingly.
It should be noted, however, that many alternative embodiments of cap assembly
10
which suitably provide for substantially radial contact between caps
20
,
30
of the cap assembly
10
and suitably remain child-resistant while remaining senior-friendly, may be apparent to one skilled in the art. All of such embodiments fall within the scope and spirit of the invention.
With reference now to
FIG. 8
, the operation of the illustrated embodiment of cap assembly
10
follows. As outer cap
30
is rotated in a “fastening” direction, outer cap
30
begins to rotate freely from inner cap
20
. As outer cap
30
continues to rotate, second on drive surface
37
of lug
36
contacts first on drive surface
27
of ramp
26
in substantially surface-to-surface contact. Throughout the rotation of outer cap
30
, lug
36
remains in surface-to-surface contact across lug
36
and ramp
26
. The continued rotation of outer cap
30
causes inner cap
20
to rotate in tandem with outer cap
30
, thus fastening cap assembly
10
to the container.
Now, with reference to
FIG. 8
b,
as outer cap
30
is rotated in an “unfastening” direction, outer cap
30
again begins to rotate freely. As outer cap
30
continues to rotate, second off drive surface
35
of lug
36
contacts first off drive surface
25
of ramp
26
, in, as described above, “line” or “surface-to-surface” contact.
However, when outer cap
30
is merely rotated in the unfastening direction, second off drive surface
35
of lug
36
slides over first off drive surface
25
of ramp
26
. Inner cap
20
and outer cap
30
thus do not turn in tandem, and cap assembly
10
remains fastened to the container, thereby making cap assembly
10
child-resistant. In order to remove cap assembly
10
, downward force is applied to cap assembly
10
in order to counteract the sliding tendency of lugs
36
over ramps
26
.
However, in accordance with this embodiment of the present invention, the line or surface-to-surface contact means less torque and/or downward force is required to remove cap assembly
10
. Cap assembly
10
thus has the benefit that assembly
10
remains child-resistant, yet is substantially more senior-friendly.
For example, in tests of cap assembly
10
embodying the present invention, surprising and unexpected results were obtained. In tests of cap assembly
10
, packages sealed by cap assembly
10
were provided to ten seniors and ten children. The respective groups were told to open the packages and timed while doing so. For the senior group, the first attempt at opening was performed on a package which had never been opened. Such a test is significant since packages which have not been previously opened generally tend to require greater amounts of force to open. If the senior test subject is successful at the first opening, the same test subject then re-seals the package and is asked to open the package again. However, in contrast, in the child test group, the children are only given packages which have been re-sealed by seniors. This is significant because seniors and children generally do not refasten cap assemblies to the package as tightly as the caps are torqued before having been previously opened.
The following tables show that, with respect to the present embodiment of cap assembly
10
, seniors are quite successful at opening cap assembly
10
, usually in a matter of seconds, while not a single child could successfully open cap assembly
10
within five minutes on a first attempt. In addition, no child test subject was able to remove cap assembly
10
which had been removed and re-fastened by a senior within five minutes on a second attempt.
|
Child Test Package Results
|
First Attempt
Second Attempt
|
Age
at Opening
at Opening
|
(in Months)
(no demonstration)
(with demonstration)
|
|
51
301 (fail)
301 (fail)
|
47
301 (fail)
301 (fail)
|
51
301 (fail)
301 (fail)
|
51
301 (fail)
301 (fail)
|
46
301 (fail)
301 (fail)
|
44
301 (fail)
301 (fail)
|
46
301 (fail)
301 (fail)
|
42
301 (fail)
301 (fail)
|
45
301 (fail)
301 (fail)
|
44
301 (fail)
301 (fail)
|
|
|
Senior Test Package Results
|
Age
First Opening
Second Opening
|
(in Years)
(fail = 301 seconds)
(fail = 61 seconds)
|
|
68
14 seconds
6 seconds
|
66
9 seconds
2 seconds
|
60
3 seconds
3 seconds
|
70
9 seconds
6 seconds
|
69
25 seconds
9 seconds
|
68
13 seconds
3 seconds
|
69
1 second
5 seconds
|
66
6 seconds
3 seconds
|
70
11 seconds
5 seconds
|
67
3 seconds
5 seconds
|
|
Thus, as illustrated above, cap assembly
10
effectively prevents children from removing cap assembly
10
, yet remains senior-friendly, allowing seniors to remove cap assembly
10
without substantial difficulty.
Finally, the above described embodiment are merely illustrative of particular embodiments of the invention, and, as mentioned above, many alternative embodiments of cap assembly
10
may provide for substantially radial contact between caps
20
,
30
of the cap assembly
10
and suitably remain child-resistant while remaining senior-friendly. Accordingly, it many modifications of structure, arrangement, proportions, the elements, materials and components, used in the practice of the invention and not specifically described may be varied and particularly adapted for a specific applications and operating requirements, all without departing from the scope and spirit of the invention.
Claims
- 1. A child-resistant cap assembly, comprising:an inner cap with at least one inner cap projection having a complex angled surface; and an outer cap, wherein said outer cap has a retaining mechanism which engages said inner cap such that said inner cap and said outer cap are freely rotatable relative to each other, and wherein said outer cap has at least one outer cap projection, wherein said outer cap projection and said inner cap projection engage by radial contact over a length on said complex angled surface when unfastening the cap assembly.
- 2. A cap assembly according to claim 1, wherein said inner cap projection has a first off drive surface and a first on drive surface and said outer cap projection has a second off drive surface and a second on drive surface, wherein said first off drive surface corresponds to said second off drive surface and said first on drive surface corresponds to said second on drive surface.
- 3. A cap assembly according to claim 1, wherein said inner cap projection and said outer cap projection engage by radial contact in the form of line contact.
- 4. A cap assembly according to claim 1, wherein said inner cap projection and said outer cap projection engage by radial contact in the form of surface to surface contact.
- 5. A cap assembly according to claim 1, wherein said retaining mechanism is an annular lip.
- 6. A child-resistant cap assembly, comprising:an inner cap, wherein said inner cap has a ramp having a first off drive surface formed as a first complex angle; and an outer cap, wherein said outer cap has a lug having a second off drive surface configured to engage said first off drive surface of said ramp by radial contact over a length on said first off drive surface, wherein said outer cap has a retaining mechanism which rotatably retains said inner cap.
- 7. A cap assembly according to claim 6, wherein said lug engages said ramp by radial contact in the form of line contact.
- 8. A cap assembly according to claim 6, wherein said lug engages said ramp by radial contact in the form of surface to surface contact.
- 9. A cap assembly according to claim 6, wherein said retaining mechanism is an annular lip.
US Referenced Citations (32)