Tamper evident, child resistant container

A molded plastic container/closure combination providing a tamper evident feature, a child resistant feature and a removal facilitation feature. The closure has radially extending bayonets extending from the outer skirt which fit into horizontal slots in a beam molded integrally with the sidewall of the container. Rotation of the closure in one direction brings the bayonets into the slots for locking purposes. Rotation in the opposite direction unlocks the closure and continued rotation lifts the closure relative to the container to facilitate removal. A resiliently mounted release tab must be depressed before unlocking rotation is permitted. A latch prevents depression of the release tab until anchors on the sides of the latch are fractured. Serrations acting between the tab and the bayonets provide an audible indication of rotation.

FIELD OF THE INVENTION

This invention relates to molded plastic container/closure combinations and more particularly to a container/closure combination having one or more of the following features:(a) a tamper evident feature;(b) a child resistant opening function; and(c) a feature which facilitates removal of the closure from the container.

BACKGROUND OF THE INVENTION

Molded plastic container/closure combinations are well known and used in a variety of sizes and configurations for a variety of purposes including the shipment and storage of various materials from food products to adhesives and laundry detergents. To prevent or at least indicate pilferage, it is common to incorporate a “tamper evident” feature into such combinations which provides a physical indication that the container may have been opened before reaching the end user. For example, the container and closure may be designed in such a way that it is necessary to remove a tear band before the closure can be removed.

Another feature incorporated into such containers is a complexity in the opening process which discourages or prevents opening by children; this is particularly important in the case of toxic products within the container.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a molded plastic container/closure combination having one or more of the following features.

First, the container/closure combination can have a tamper evident feature to provide a physical indication in the event the container is opened prior to reaching the end user. As hereinafter described in greater detail, this feature is provided by forming a latch and release tab combination on the container which requires at least a partial fracture in the process of opening the container. The fracture is evident from visual inspection of the container and provides evidence of possible tampering. No tear band is required.

Secondly, the present invention can provide a child resistant feature which is achieved through the incorporation of mechanisms which complicate the opening process beyond the capabilities of most children. In general, this feature is achieved by providing a latch which must first be minimally displaced and a subsequent rotation of the closure relative to the container, which rotation is only permitted after the latch has been displaced. This complicated manipulation is relatively simple and straightforward for mature humans but, in part because it requires two hands and in part because it requires a coordinated combination of actions, is too complicated for most children.

Finally, the present invention can incorporate a closure removal facilitation feature which makes it easier with persons with limited manual dexterity to remove the closure from the container. In general, this is provided by means of an arrangement in which rotation of the closure in the opening direction causes the closure to lift somewhat relative to the container. This is achieved in the illustrative embodiment by a combination of closure bayonets and container-mounted ramps which direct the bayonets upwardly when the closure is rotated.

The various features and advantages of the present invention will be best understood from reading the following specification which describes an illustrative embodiment in detail. This description is to be taken in combination with the accompanying drawings.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

Referring to the figures, there is shown a molded plastic container/closure combination10comprising a five-gallon, open top, molded plastic container12and a molded plastic closure14which is adapted to be mated to the container12so as to close and seal the container. In accordance with the various features of the invention hereinafter described, there is provided a tamper evident feature, a child resistant feature and a removal facilitation feature. The container12and closure14are preferably manufactured by injection molding high-density polyethylene in appropriate molds as are well known to persons skilled in the molding arts. The invention is, however, not limited to HDPE as a material of construction as other materials may also be used. The five-gallon size is given only by way of example.

The container12has a tapered sidewall16which terminates at the upper end in a rim18which is received within an inverted U-shaped peripheral channel structure20on the closure14. The closure14is molded with an inverted U-shaped peripheral channel which receives the top edge18of the container and includes a gasket45held in place by a small retainer rib24. Closure14includes an annular outer skirt22with integrally molded and uniformly angularly spaced, radially outwardly extending bayonets30formed thereon. In this example, six bayonets30are used and they each define an included angle of slightly less than 30° with gaps of slightly more than 30° between the bayonets. More or fewer bayonets30may also be used in which case the included angles change.

The container12is molded integrally with a “beam”26which takes the form of an annular collar, the top of which is essentially coplanar with the top rim18of the container12. The beam26is approximately 1 inch to 1¼ inches in vertical dimension and extends continuously around the container sidewall except for a gap27, the purpose of which is hereinafter described.

The beam26stands radially off of the container sidewall16about ¼″ or more by means of a rib28upon which the bayonets30are seated when the closure14is placed on the container12in such a way as to cause the skirt22to extend downwardly into the radial gap between the container sidewall16and the outer portion of the beam26, as shown inFIGS. 3A,3B,6and9. The rib28is not flat all the way around the container; rather, it is interrupted by six elevated sections34which perform two functions: first, the elevated portion34define six horizontal and circumferential one-way slots into which the bayonets30may be rotated in one direction until they reach an end stop36to lock the closure14down to the container12. The term “slot” does not here imply that the bayonets enter an area with both a top and bottom. Indeed, the rib is generally relieved under the elevated riser portions34. Secondly, the elevated portions34form ramps on their exterior surfaces which the bayonets ride up on to lift the closure relative to the container12approximately ¼″ when the closure is rotated approximately 60° in the opposite direction; i.e., twice as far as is necessary to unlock the closure relative to the container by bringing the bayonets30out from under the raised portions34of the rib28as previously described. The portions34also can function to cam the closure down onto the top of the container12when rotated in the locking direction thereby to improve the seal between container and closure. A gasket seal can be provided as shown. Alternatively, a vented, gasketless design can be used.

As shown inFIGS. 3A and 3B, serrations32are formed on the bottom surfaces of the bayonets30to provide an audible indication of rotation relative to a container feature36hereinafter described.

As indicated above, the beam26is interrupted by a gap27within which is molded a release tab36having serrations37formed on the upper surface thereof The serrations37coact with the serrations32on the bottoms of the bayonets30to provide the audible indication of rotation when the release tab is in a position which permits rotation of the closure14relative to the container12. The release tab36is hinged at its inner extremity to the container sidewall such that it may be resiliently depressed downwardly out of its normal position where it prevents rotation of the closure14by interfering contact with the edges of the bayonets30, to a lowered position where it no longer interferes with the bayonets30and therefore permits rotation of the closure14relative to the container12for locking and unlocking purposes. In the lowered position, the release tab allows coaction between the serrations32,37as shown inFIG. 3B.

To provide a tamper evident feature, an arcuate latch38conforming generally to the container/closure combination is molded into the container sidewall with a living bottom hinge39and frangible side anchors40. The latch38is located so as to prevent downward depression of the release tab36. However, the frangible anchors40are thin and can be relatively easily fractured by pressing inwardly on the latch38after which the tab36can be pressed down, by bending it around the hinge39as shown inFIG. 3Bto a position where the release tab36no longer interferes with the bayonets and therefore allows rotation of the closure14relative to the container12to permit the opening manipulation.

Summarizing, operation of the container/closure combination is essentially as follows: Once the container12is filled, the closure14is attached to the container12typically by machinery and the bayonets30are rotated into the horizontal slots provided by the riser portions34of the rib28until the release tab36is centered between bayonets30, care being taken to prevent fracture of the anchors40on the sides of the latch38. To remove the closure14from the container12, one first depresses the latch38inwardly to fracture the anchors40until the release tab36may be pushed downwardly. With the release tab36deflected downwardly around its own living hinge, the closure14is rotated to bring the bayonets30out from under the raised portions34of the rib28until they are in the 30° clearance gaps between slots. At this point, the closure14may be removed by lifting it straight up, relative to the container12. However, an additional assist feature is provided for the convenience of persons having limited manual dexterity through continued rotation of the closure14through another angle of rotation of approximately 30° thereby causing the bayonets to ride up on the ramps provided by the raised portions34thus lifting the closure14relative to the container12as best shown inFIGS. 9 through 11. Unlike a conventional screw thread, the risers34lift all bayonets at once and to the same degree until they sit atop the risers34. Four features of the invention are thus provided:(1) A tamper evident feature in the form of the fracturable anchors40which are broken to operate the latch38;(2) A child resistant feature which involves the combination of the latch38and the complex action required to depress the release tab36and rotate the closure14at the same time;(3) A removal facilitation feature provided by ramps which coact with the bayonets30to lift the closure14relative to the container upon continued rotation of the closure14in the opening or unlocking direction. As indicated above, these features can be used individually as well as in combination; and(4) An audible indication of rotation.

The invention has been described with reference to an illustrative embodiment. Various changes in design, size and proportions are possible within the scope of the invention.