Safety Closure Assembly

Abstract

A safety closure assembly of a container includes a cap having internal interrupted threads and a container neck having external specially arranged guide surfaces. These surfaces define essentially three zones on the neck. At the neck top is a mating thread zone for receiving the interrupted threads. A second thread zone is spaced from the top and cooperates in assuring a liquid-tight seal across the neck opening by the cap. Intermediate these threaded zones is a zone which is only traversed by the cap-thread elements upon the application of deliberate and informed movement or manipulation of the cap other than the ordinary unscrewing action. This manipulation may assume the form of either an application of increased force to urge one of the thread elements passed a zone of interference or the axial shifting of the cap through an access zone for the thread elements after a stop is encountered forbidding further turning of the cap relative to the neck; or the manipulation may require a combination of these cap movements.

Description

BACKGROUND OF THE INVENTION

Statistics show that many accidents and fatalities occur, particularly among children, through the accidental or unsuspecting consumption of drugs, poisons and many household products. Many packagers of such products have reacted as a result of a strong social conscience and have adopted safety closures which are child-deterring by nature or require adult strength to open the package. However, this discipline and practice is not industry or nation-wide and potentially dangerous products without safe or child-proof packaging continues to be marketed.

There has been an impressive decline in child poisoning from drugs because of the employment of a variety of safety closures and packaging techniques. Nonetheless, this remains a problem and with the modern, busy mother, household products are increasingly resulting in hazards and harm to children.

Consequently, legislation has been proposed and appears to be imminent for purposes of rectifying the situation by placing the responsibility of child-resistant products on the packager.

Although this packaging problem on the surface may superficially appear to be easily solvable, in reality it is complex. Closures that are simply and effectively safe are scarce, if non-existent, particularly in the minds of many packagers.

SUMMARY OF THE INVENTION

The present invention has as one of its principal objects a safety closure assembly that eliminates the stated problems and advantageously far exceeds the limited attributes of safety caps heretofore proposed.

Another object is to provide a safety closure assembly that is comparable in price and cost to existing conventional screw cap closures.

A further and very important advantage is a safety closure assembly which is capable of providing a liquid-tight seal and a tight seal for dry products as well.

Another object is to provide a safety closure assembly which is adaptable to plastic as well as glass containers.

An additional object is to provide a safety closure assembly and particularly a cap therefor which may be applied with conventional capping equipment.

BRIEF DESCRIPTION OF THE FIGURES

In the drawings:

FIG. 1 is an exploded perspective view of a safety closure assembly of this invention showing a safety cap spaced from the neck of the container, the latter shown fragmentarily;

FIG. 2a is a fragmentary longitudinal sectional view of the cap associated with the neck taken along the line 2a -2a of FIG. 1;

FIG. 2b is a cross-sectional view taken along line 2b --2b of FIG. 2a but showing the cap disposed on the neck in the position depicted by FIG. 5;

FIG. 3 is a diagrammatic view showing the cap and neck in flattened planar relationship for purposes of showing the relationship and operation of the detailed parts of the assembly which in this figure are in a locked position with the cap in sealing relationship across the mouth of the bottle neck;

FIG. 4 is a similar view showing the cap in the process of being unscrewed and approaching the interference zone;

FIG. 5 is a similar view with the lead thread element at the maximum zone of interference during the removal of the cap;

FIG. 6 shows the cap further removed and the trailing thread element guiding the cap upwardly as a result of engagement with a camming surface whereby the interrupted threads of the cap are guided into mating engagement with the upper threaded portion of the container neck, the latter mating relationship being shown in phantom;

FIG. 7 is an exploded perspective view of a safety closure assembly in accordance with an alternate embodiment of this invention;

FIG. 8 is a sectional view taken along the line 8--8 of FIG. 7 showing the safety cap in sealing relationship across the mouth of the container neck;

FIG. 9 is a flattened planar view of the safety closure assembly of this embodiment showing the relationship of the parts when the cap is fully threaded on the container neck and in sealing relationship across the neck mouth;

FIG. 10 shows the cap partially unthreaded from the container neck and the lead thread in engagement with a stop which requires the cap to be axially pulled whereupon the lead thread is passed through a zone which may or may not include an interference fit requiring adult force to pull this lead thread through this zone;

FIG. 11 shows the lead thread after it passes through the safety zone with the trailing thread element encountering a second stop which, in this instance, requires the cap to be given a reverse twist and then lifted axially again to clear this stop; and

FIG. 12 shows the trailing thread element clearing the second stop in order that the interrupted threads may now mate with the upper threaded portion of the container neck in a fashion shown in phantom.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Initially, reference is made to the embodiment of safety closure assembly 20, shown in FIGS. 1-6, in which a cap 22 is adapted to be coupled with the neck 24 of the container 26. Both the container and neck may obviously assume any one of a variety of different configurations. In the illustrated embodiment, the neck 24 is reduced in diameter and defines an opening or mouth 28 which provides access to the interior of the container and its contents.

With the exception of its thread construction and arrangement, the cap 22, for the most part, is advantageously of conventional construction including a top wall 30 from which extends a depending cylindrical skirt 32. A liner 34 may be secured to the inner face of the top wall 30 for providing a liquid-tight seal across the mouth 28 of the container neck 24 when the cap 22 is completely drawn down on the neck 24. Towards this end, the interior of the skirt 32 is provided with interrupted threads having a plurality of spaced thread elements 36, lugs or similar projections. Obviously, the size and shape of the thread 36 may be varied; and for purposes of the specific embodiment of FIGS. 1 to 6 wherein it is desired to have lead thread elements 36a cooperate inproviding an interference zone which will be described in detail shortly, the thread elements may be shaped as shown in plan in FIG. 2b.

The exterior of the neck 24 is provided with cooperating surfaces for receiving the interrupted threads 36 in securing the cap 22 across the mouth 28 and permit its removal only after the child-deterrent position is encountered. In this connection, a threaded zone 38 including mating threads 40 is located adjacent the mouth 28.

Threads 40 extend into an interference zone 42 through which the lead thread element 36a is adapted to pass. This zone is defined by guide surfaces for the lead thread element 36a which includes a capping guide or cam surface 44 and an uncapping guide or cam surface 46. Surface 44 guides the leading edge of thread element 36a downwardly during the capping operation; and surface 46 guides the trailing edge of thread element 36a upwardly during the uncapping operation. During uncapping, the lead thread element 36a and guide surfaces 44 and 46 eventually provide an interference fit at zone 42 which requires adult strength to overcome thereby serving as a child deterrent or safety feature. The guiding of the cap during the uncapping operation and particularly through the interference zone 42 is further facilitated by the camming surface 48 against which the trailing edge of trailing thread element 36d is adapted to engage.

As the thread element 36a passes through the interference zone, the remaining thread elements 36b, 36c and 36d pass through openings 50b, 50c and 50d, respectively, into a second threaded zone 52. This threaded zone 52 includes thread elements 54a, 54b, 54c and 54d which mate with the cap thread elements 36a, 36b, 36c and 36d, respectively. When thread elements 36 and 54 engage, the cap 22 is drawn down tightly to cause the liner 34 to seal across mouth 28 in a liquid-tight manner. This type of seal is not possible with most safety caps heretofore proposed. A valve seal in the form of a downwardly depending concentric lip on the inside of cap top wall 30 could also be provided in lieu of the cap liner to serve the same purpose and provide an additional advantage. If the depth of the valve seal is greater than the distance the cap 22 must be pulled through the interference zone 42, the possibility of accidental spillage will be minimized. This is especially true on the safety closure configuration that requires an upward pull as disclosed in FIGS. 7 to 12.

In operation and assuming that the cap 22 is fully threaded on the container neck 24 so that the mouth 28 is sealed by the cap liner 34, the cap is twisted or turned from the position shown in FIG. 3 until the lead thread element 36 engages with the camming or guide surface 46; and this thread element 36a is guided upwardly into the interference zone 42 at which point the parts are positioned as shown in FIG. 4. Thereafter, the lead thread element 36a must traverse this interference zone 42 and in order to accomplish this, adult force or pressure is required because of the interference fit which is at a maximum when the parts are disposed as in FIG. 5. Further twisting of the cap will clear the lead thread element 36a of the interference zone 42 at which time thread elements 36b, 36c and 36d will also clear their respective openings 50b, 50c and 50d provided on the cap neck 24. Eventually the trailing edge of the trailing thread element 36d will engage with the camming surface 48, as shown in FIG. 6, to direct the cap 22 upwardly and eventually have the interrupted threads 36 mate with thread 40 at the upper part of the bottle neck 24, as shown in phantom in FIG. 6. The cap may then be readily removed. The reverse turning or screwing procedure need only be executed in order to place the cap 22 over the container neck to seal the container contents.

In the embodiment of safety closure assembly 20', illustrated in FIGS. 7 to 12, parts similar to the parts of the preceding embodiment will be similarly numbered with an accompanying prime. Thus, safety closure assembly 20' will include a safety cap 22' and the neck 24' of the container 26'. The cap will be provided with the interrupted threads 36' while the cap will include an upper threaded zone 38' and a lower threaded zone 52' with an interposed zone 42' which may or may not be of the interference variety as in the preceding embodiment. Of importance, however, is the requirement that the cap 22' be turned relative to the neck 24' and when the leading thread element 36a' approaches the zone 42', axial displacement of the cap on the neck must be performed. This compound movement of the cap relative to the neck is designed to render it extremely difficult for a child to accidentally remove the cap from the neck. However, the disposition of parts of the cap and the neck are such that conventional capping equipment may thread the cap onto the neck as in the previous embodiment.

In operation and assuming that the cap 22' is fully threaded on the neck 24', as shown in FIG. 8, the parts of the cap and neck will assume the position shown in FIG. 9. The cap 22' is then turned until the leading thread element 36a' comes in contact with the stop 46' preventing further turning of the cap 22' relative to the neck 24', as shown in FIG. 10. In order for the thread element 36a' to clear the stop 46' as well as the zone 42', the cap 22' is required to be axially pulled or lifted. As an added precaution for child safety, the zone 42' may provide an interference between the leading thread element 36a' and the opposing surfaces of camming surface 44' and stop 46'. As shown in FIG. 11, a second stop against further turning movement of the cap 22' relative to the neck 24' is provided in the form of the interengagement of the trailing thread element 36d' and the stop 48'. The projection 56 at the top of the stop 48' may also be provided and may be cleared by reverse twisting of the cap 22' accompanied by a slight axial pull. Thereafter, the thread elements 36' will mate with the upper thread 40' upon further turning of the cap 22, as shown in FIG. 12. Eventually, cap 22' will be removed from the container neck 24' to obtain access to the container interior and contents.

In addition to permitting the cap of the preceding embodiments to be threaded on the container neck by means of conventional or standard capping equipment, any container or bottle finish or material may be employed including both plastic and glass. Of course, the cap may be made of any desired or acceptable material used for capping the selected bottle and sealing the desired container contents.

Thus, the several aforenoted objects and advantages are most effectively attained. Although several somewhat preferred embodiments have been disclosed or described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

Claims

I claim:

1. A safety closure assembly comprising in combination:

a container neck defining an opening through which the container contents may be dispensed;

a closure cap coupled with the container neck and extending across the opening and cooperating in confining the contents within the container until it is desired to remove same therefrom;

the exterior of the neck and the interior of the cap having cooperating interengaging means for coupling the cap to the neck in relatively easy fashion and permit the uncoupling of the cap from the neck only upon informed deliberate manipulation of the cap relative to the neck:

said cooperating interengaging means comprising an interrupted thread and guiding surfaces for cooperating in guiding the relative path of travel of the threads, said guiding surfaces including an interference zone through which one of the interrupted thread elements must pass and such passage is only permitted upon informed deliberate manipulation of the cap relative to the neck.

2. The invention in accordance with claim 1 wherein the cap includes a cylindrical skirt, the interrupted thread is in the form of lugs projecting radially inwardly from the skirt.

3. The invention in accordance with claim 1 wherein the guiding surfaces are on the exterior of the neck.

4. The invention in accordance with claim 3 wherein the guiding surfaces include a mating threaded portion on the exterior of the neck between the opening and the interference zone.

5. The invention in accordance with claim 4 wherein the guiding surfaces include a second mating threaded portion on the exterior of the neck with the interference zone being interposed.

6. The invention in accordance with claim 1 wherein the guiding surfaces include threaded portions, and the guiding surfaces defining the interference zone include a stopping surface at a greater angle relative to the threaded portion in a plane normal to the axial direction of the container and cap.

7. The invention in accordance with claim 6 wherein the stopping surface is normal to said plane.

8. The invention in accordance with claim 6 wherein the stopping surface is provided with a camming surface against which said one interrupted thread element is adapted to move prior to passing through said zone.

9. The invention in accordance with claim 8 wherein a second camming surface is at the other side of said zone whereby the one interrupted thread element serves as a cam follower when both placing the cap on the neck and removing it therefrom.

10. The invention in accordance with claim 6 wherein a camming surface is adjacent the zone and is adapted to be engaged by another of the interrupted thread elements in guiding the one thread element through the zone.

11. The invention in accordance with claim 10 wherein the camming surface is normal to the plane and includes a stop which is adapted to be engaged by said another of said thread elements to inhibit the further movement of the cap axially relative to the neck and permit such further movement upon reverse turning of the cap to permit said another threaded element to clear the stop.

12. A safety closure assembly comprising in combination:

a container neck defining an opening through which the container contents may be dispensed;

a closure cap coupled with the container neck and extending across the opening and cooperating in confining the contents within the container until it is desired to remove same therefrom;

the exterior of the neck and the interior of the cap having cooperating interengaging means for coupling the cap to the neck in relatively easy fashion and permit the uncoupling of the cap from the neck only upon informed deliberate manipulation of the cap relative to the neck;

said cooperating interengaging means comprising an interrupted thread and guiding surfaces for cooperating in guiding the relative path of travel of the threads, said guiding surfaces including a zone through which one of the interruptions of the thread must pass, and means for permitting the one interruption to pass the zone when the cap and neck are moved in an accentuated axial direction relative to one another, and a stop against which the one interruption is adapted to impinge prior to passage through said zone when said cap is turned in an attempt to unscrew it off the container neck.

13. In a safety closure assembly for a container having outlet surfaces defining an opening, capping surfaces extending over the opening with interrupted threads on one of said surfaces, the improvement of:

guiding surfaces including an interference zone through which one of the interrupted thread elements must pass and such passage is only permitted upon informed deliberate manipulation of the cap relative to the neck.

14. In a safety closure assembly for a container neck having outlet surfaces defining an opening, capping surfaces extending over the opening with interrupted threads on one of said surfaces, the improvement of:

cooperating interengaging means comprising said interrupted thread and guiding surfaces for cooperating in guiding the relative path of travel of the threads, said guiding surfaces including a zone through which one of the interruptions of the thread must pass, and means for permitting the one interruption to pass the zone when the cap and neck are moved in an accentuated axial direction relative to one another, and a stop against which the one interruption is adapted to impinge prior to passage through said zone when said cap is turned in an attempt to unscrew it off the container neck.