Double lock lid with flexible tab

A container system including a lid and a container is provided. A locking structure on the skirt of the lid is situated on a tear off portion and comprises a plurality of flexible tabs positionable in an upwardly biased locked position each independently engaging the container within an annular cut away on the container wall below a locking rib. If the lid is removed with tear off strip still engaged, the flexible tabs are biased downwardly and may break off, exposing tampering.

TECHNICAL FIELD

This disclosure relates generally to containers, and particularly to a double locking container system having a robust tamper proofing that will prevent for example a paint can or other similar container from being opened and re-sealed without any observable indication that the container has been tampered with.

BACKGROUND

Containers with lids that can be secured in place upon the container and having tamper-evident features are known.

Conventional tamper evident sealing involves an annular sealing bead that is designed such that it must be broken before the lid of a container can be removed, thus indicating that the container had been previously opened. Known solutions are not very effective however as they can often be opened without damaging the seal by using a sharp object to pry open the annular bead. Furthermore, the annular beads of known containers offer no improvement to the container's performance on any of the typical quality tests for containers, such as drop tests, leak tests mentioned below. The features also conventionally require intricate molding geometries that are difficult to effectively cool, making them challenging to mold into a part.

U.S. Pat. No. 5,249,694 discloses a lid and a container that cooperate to form a double lock. The lid comprises a skirt that comprises a ridge on the exterior wall of the skirt and a ridge on the interior wall of the skirt. The cup comprises a ridge on its exterior wall and a flange that extends outwardly from the exterior wall and the flange comprising an inner ridge. The ridges of the skirt cooperates with the ridges of the cup to form two seals. The flange of the cup is a tear strip.

U.S. Pat. No. 5,437,386 discloses a container that comprises a double wall. The inner wall has an outwardly projecting rib and the outer wall has an inwardly projecting rib. The lid comprises a peripheral portion that has an inwardly projecting rib that engages the outwardly projecting rib of the container. The end of the peripheral portion engages the inwardly projecting rib of the container. The outer wall of the container needs to be folded outwardly to allow the lid to be removed.

Accordingly, there is a need for a container system that has an effective locking system for a lid with reduced material, simplified manufacturing and improved tamper-evident features.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, a lid for a container is provided. The container has a peripheral side wall with a rim, the rim having upper and lower peripheral, annular outwardly disposed locking beads (also referred to as flanges), said beads having undersides for locking engagement with the container lid, the lid comprising: a central portion and a peripheral annular skirt adapted to overlie the container locking beads; the annular skirt defining an annular groove dividing said skirt into a skirt upper portion and a skirt lower portion; the skirt lower portion having a plurality of inwardly disposed flexible locking tabs/teeth adapted to each independently engage the underside of the container lower locking flange when said lid is positioned on said container in a locked position.

In accordance with a further aspect of the invention, the skirt lower portion forms a tear-off strip portion having a lower peripheral edge, and wherein the tear-off strip portion is formed with a circumferential reduced thickness portion located below the skirt upper portion, facilitating removal of the tear off strip.

In one aspect of the invention, the lid and the container form a sealing arrangement.

In one aspect, the tearing of the tearable portion is required to remove the lid. The tearing of the tearable portion and/or the separation of some of the flexible tabs/teeth during lid removal if the tearable portion remains on the lid during removal, serve as evidence of tampering.

It should be noted that the figures are merely examples and no limitations on the scope of the present disclosure are intended thereby. Further, the figures are generally not drawn to scale, but are drafted for purposes of convenience and clarity in illustrating various aspects of the disclosure.

DETAILED DESCRIPTION OF THE INVENTION

In various examples, the present disclosure describes a container system in which the lid and container forms a double tamper evident lock, comprising at least one ring of flexible tabs positioned on the lid, adapted to engage the container in locking engagement. Although the present disclosure provides examples, the disclosed methods and devices may be suitable for other purposes, with modification as appropriate.

The term “comprising” as used herein will be understood to mean that the list following is non-exhaustive and may or may not include any other additional suitable items, for example one or more further feature(s), component(s) and/or ingredient(s) as appropriate.

Reference is now made toFIG.1, which shows a bottom view of the lid100.

In some embodiments, the lid100is circular, as shown inFIG.1. In some embodiments, the lid is rectangular, square, elliptical, parallelogram, or any other suitable shape for a lid.

As can be seen inFIGS.1to3A, in some embodiments, the lid100has a peripheral skirt108extending downwardly from a position close to the outer edge of the lid100. In some embodiments, the skirt108extends from the outer edge of the lid100. In some embodiments, the skirt108is configured offset from the outer edge of the lid100such that the outer periphery of the lid100may be used for holding the lid100. In some embodiments, one or more strengthening rib102is provided on the underside116of the lid100, as shown inFIGS.1and2. In some embodiments, the rib102extends from a central portion of the lid100toward the outer edge of the lid100. In some embodiments, a gap107is formed between the rib102and the skirt108. In some embodiments, a ridge105is provided at the end of the strengthening ribs102facing the skirt108, the ridge105extending downwardly from the underside116of the lid100. In some embodiments, the ridge105does not extend as far from the underside116of the lid100as the strengthening rib102. In some embodiments, the ridge105circumferentially connects the outer ends of the strengthening ribs102, forming a closed loop. In some embodiments, a circumferential ridge103is provided on the interior surface of the skirt108, and the circumferential ridge/flange103extends inwardly from the interior surface of the skirt108. As shown in the Figures, a lid100for a container is provided. The container200has a peripheral side wall with a rim, said rim having upper and lower peripheral, annular outwardly disposed locking flanges204,201, said flanges having undersides for locking engagement with the container lid. The lid comprises a central portion and a peripheral annular skirt108adapted to overlie the container locking flanges204,201. The annular skirt108defining an annular groove110dividing said skirt into a skirt upper portion108U located adjacent to the container upper locking flange, and a lower portion108L located adjacent to the container lower locking flange; the skirt upper portion having an inwardly disposed locking flange103adapted to engage the underside of the container upper locking flange204in snap fit engagement, the skirt lower portion having a plurality of inwardly disposed flexible locking tabs101adapted to engage the underside of the container lower locking flange201when said lid is positioned on said container in a locked position.

In the example embodiment shown, the skirt lower portion forms a tear-off strip portion114having a lower peripheral edge, and wherein the tear-off strip portion is formed with a circumferential reduced thickness portion110(also referred to as annular groove) located between the skirt upper portion and skirt lower portion, facilitating removal of the tear off strip114. In some embodiments, the weakened area is a weakened line110as shown inFIG.2. In some embodiments, such as shown inFIG.3A, the tearable portion114includes a pulling portion109that is configured to facilitate pulling the tearable portion114off the lid100. For example, the pulling portion109may be provided with a rough surface to increase friction when it is being pulled. In some embodiments, the weakened line110extends along a portion of the flange. In some embodiments, the weakened line110extends along the full circumference of the skirt108. In some embodiments, the weakened area comprises a weakened line that extends downwardly to the lower edge113of the skirt108.

The lid may further comprise an annular sealing groove107located between the lid central portion and the peripheral annular skirt, the sealing groove being adopted to sealingly engage the rim of the container.

In the embodiment of the invention shown in the drawings, a tamper-evident feature is incorporated including a series of foldable locking tabs (also referred to as teeth) on the lid in place of the single annular locking bead known in the art. This incorporates multiple discontinuous contact locking areas that would be very difficult to pry open without damaging the container. Further, if each feature is independently connecting the lid and the pail, the force connecting the two parts will be increased and less susceptible to damage. If one tab feature is disconnected it won't impact the other features' ability to grip the lid. To achieve an effective seal each individual feature (each tooth/tab) must effectively grip the container.

In the example embodiment, the design consists of a ring of interconnected, small, rectangular tabs101that protrude from the lid100at a downward angle when lid is not engaged on container, shown inFIG.2. As lid is pressed on top of a container, as will be described in detail, each tab101engages a mating feature on the container wall. Each tab grips under a mating feature in the container that in an example embodiment consists of a locking ridge201and a radial undercut520shown inFIGS.3and3a. The container includes a tamper reducing ridge202feature that would encompass the bottom skirt feature of the lid engaging a ridge of the container to complete the tamper-evident seal. Details of these feature will be discussed below.

In an example embodiment, a plurality of flexible tabs/teeth101are provided along the circumference of the interior surface of the skirt108of the lid. The tabs101are disposed between the circumferential upper locking flange103and the lower edge113of the skirt108. The tabs101are separate from each other, connected only by the interior surface of the skirt108. In some embodiments, there is a ridge (not shown) running at the roots of the tabs101along the circumference of the interior surface of the skirt108, connecting the tabs101. In some embodiments, a flexible ring is provided in place of or in addition to the flexible tabs101. By using a plurality of individual tabs101instead of a ridge, a saving in plastic is realized. In addition, the individual tabs101may provide individual locking contact on the container that cannot be easily tampered. The example embodiment of the invention shown is a container and lid combination that will incorporate a ring of roughly 100 foldable locking teeth on the lid to engage the container to provide tamper-evident sealing and improve part performance.

An example embodiment of the invention is designed to pass a part drop test (the part must withstand a 1.2 m drop without signs of leakage), vibration test (the part is shaken and cannot show signs of leakage), and leak proof test (the part is submerged under water and cannot show signs of leakage) requirements to ensure improved lid-to-container engagement. The example embodiment described with the below specifications passed the above noted drop, vibration and leak proof tests.

In the locked position with lid on container, the flexible teeth/tabs101is an upwardly biased position shown inFIG.3. The flexible teeth/tabs101, bias downwardly if the lid is removed from said container with tear off strip114still engaged and are designed to maintain this upwardly biased folded position. In an example embodiment, the flexible locking tabs (also referred to as foldable locking teeth) are spaced equally around the skirt lower portion. It should be understood that the flexible locking teeth may not in fact be spaced evenly around the lid as they may be interspersed around the circumference unevenly, and may in fact not all be sized or shaped the same as each other.

FIGS.2-4Bshow sectional views of the lid100and container200. In some embodiments, the lid100comprises a central portion104on the upper side. In some embodiments, the central portion104is recessed, separated from the periphery111of the lid110by a sidewall115. When the lid100has a recessed central portion104at the upper side, the periphery111of the lid100is in the form of a plateau. In some embodiments, the central portion104is not recessed, and the periphery111and the central portion104are continuous. In some embodiments, the central portion104and the periphery111are co-planar.

The lid100has a skirt108. In some embodiments, the skirt108extends downwardly from outer edge of the periphery111. In some embodiments, the skirt108extends downwardly and outwardly from the outer edge of the periphery111, as shown inFIG.2. In some embodiments, the skirt108is set back from the outer edge of the periphery111. In some embodiments, the skirt108is set back from the outer edge of the periphery111, exposing a portion of the periphery111that facilitates handling of the lid100.

In some embodiments, a ridge or inwardly disposed locking flange103is positioned on the interior surface112of the upper portion of skirt108, the ridge103projecting inwardly from the interior surface112of the skirt108. In some embodiments, the ridge103extends along the circumference of the interior surface112of the skirt108to form a closed loop. In some embodiments, the ridge103extends inwardly and upwardly from the interior surface112of the skirt108. The ridge or inwardly disposed locking flange is adapted to engage the underside of the container upper locking flange204in snap fit engagement when placed upon the lid.

As shown in the drawings, flexible locking teeth/tabs101are provided on the interior surface112of the skirt108, the teeth/tabs101extending inwardly from the interior surface112of the skirt108. The tabs101are positioned below the inwardly disposed locking flange103, i.e., the tabs101are between the lower edge113of the skirt108and the flange103. In some embodiments, the tabs101are movable from an open position inFIG.2to a locked position as shown inFIG.3. In the open position, the tabs101extends inwardly and downwardly from the interior surface112of the skirt108. In the locked position, with lid on container, each tooth/tab101extends inwardly and upwardly from the interior surface112of the skirt108. The movement of the tabs101from the open position to the locked position will be described.

In some embodiments, strengthening ribs102are provided on the underside116of the lid100as described before. In some embodiments, the ribs102extend downwardly from the underside116the lid100and outwardly toward the skirt108. In some embodiments, the ribs102do not reach the skirt108, defining a gap107between the ribs102and the skirt108. In some embodiments, the ribs102extends from the underside of the central portion104to the underside of the periphery111. The ribs102may enhance the structure of the lid100. In some embodiments, a ridge105is positioned at the outer end of the ribs102facing the skirt108. The ridge105extends downwardly from the underside of the periphery111. The ribs102may strengthen the ridge105and vice versa. In other alternate embodiments, ribs102may not be present on the lid and ridge105may extend further down than illustrated inFIG.3; for example ridge105may extend downwardly beyond the position of ridge103.

In some embodiments, the ridge105extends along an exterior circumference defined by the outer ends of the ribs102, connecting the outer ends of the ribs102and forming a closed loop.

Reference is now made toFIGS.3and3A, which show the container system of the disclosure where the lid100engages the container200.

The container200has a sidewall206that defines an opening, which the lid100covers. The wall206has an interior surface207and an exterior surface208. The opening is in a shape corresponding to the shape of the skirt108of lid.

In some embodiments, a ridge/bead204is provided on the exterior surface208close to the upper end of the sidewall206of the container. In some embodiments, another ridge201is also provided and situated distally from the opening than the ridge204. In some embodiments, the ridge201extends further from the exterior surface208than does the ridge204. In some embodiments, the ridge204extends along the full circumference of the exterior surface208of the sidewall206. In some embodiments, the ridge201extends along the full circumference of the exterior surface208of the sidewall206.

When the lid100and the container200are engaged, a double lock configuration is formed as shown inFIG.3.

In some embodiments, the ridge204and the ridge103press against each other in snap fit engagement, forming the first lock. In some embodiments, the surface of the ridge204and the surface of the ridge103are designed such that they cooperate to prevent each other from separating easily. For example, one surface may be concave and the other surface may be correspondingly convex so that the two surfaces snugly fit to each other. In some embodiments, the ridge204has a lower flat surface that extends downwardly and outwardly from the exterior surface208, while the ridge103has an upper flat surface that extends upwardly and inwardly from the interior surface112of the skirt108, such that the two surfaces form a locking arrangement.

In the example embodiments of the figures, when the lid is pressed onto the container, the peripheral edge of ridge201engages each of the teeth/tabs101moving them into a locked position against the container, to form the second lock. In an example embodiment the teeth sit in an upward bias position within an annular undercut520below the ridge201in the locked position. Before the lid100is pushed on the container200, the teeth/tabs101are in the open position, extending inwardly and downwardly from the interior surface112of the skirt108. During the process in which the lid100is put on the container200, the end of each of the teeth/tab101are pushed by the ridge201such that the tabs101move from the open position to the locked position seen inFIG.3. In the locked position, each of the tabs/teeth extend inwardly and upwardly from the interior surface112of the skirt108, abutting the wall211of the recessed undercut portion520(seeFIG.4B). After the lid100is pushed into the locked position, the ridge201blocks upward movement of the tabs101. In some embodiments, the ends of the tabs101engage the ridge201. In some embodiments, the ends of the tabs101are separated from the ridge201.

In alternate embodiments, prior to engagement on the container, the lid is positioned in a plunging station such that tabs101may be moved into locked position by a fixture400, shown inFIG.4C-4E. An embodiment of a fixture400is placed below the peripheral skirt108and positioned and shaped such that the fixture upper surface401engages and folds tabs101upwardly around the circumference of the lid during a plunging process. When in the folded position, lower surface402rests against the bottom edge113of the skirt. The fixture400acts to assist the folding the teeth101on the lid in upward direction, so the lid can snap onto the container easily during the attachment stage. The fixture400acts as a plunger during the lid production process as follows: the lid100is moved by conveyer to a fixed position adjacent the fixture400and the fixture400is driven towards the lid by pneumatic means resulting in bending the teeth upwards in folded position, shown in the sequence fromFIGS.4C to4E. Once the teeth101are in the upwardly biased position, the fixture (plunger)400moves back away from the lid, and the lid moves to a stacking station (not shown) with the teeth101in ideal position, namely upwardly biased (such as shown inFIG.4E). The next lid100moves in to this fixed position to be plunged by the fixture400and move its teeth101to the upwardly biases position. In summary, the fixture/plunger acts during the production process to ensure the teeth101are folded in upward position prior to insertion on each container. Although an embodiment of fixture400is shown, it may be shaped accordingly to the circumference and specifications of the lid, which may be circular, square, rectangular or other conceivable shape.

In some embodiments, one or more rib205is provided between the ridge201and the sidewall206of the container. The rib205extends between the exterior surface208of the sidewall and the ridge201. In some embodiments, the rib205supports the ridge201. In some embodiments, the rib205prevents the ridge201from being pushed inwardly to release the tabs101.

In some embodiments, the upper portion of the sidewall206is received in the gap107between the ribs102and the skirt108. In some embodiments, the ridge105pushes the sidewall206outwardly. In some embodiments, the ribs102support the sidewall206outwardly. In some embodiments, the locking between the lid100and the container200is enhanced when the sidewall206is pushed outwardly.

In some embodiments, a ridge202is provided extending from the container wall that extends away from the exterior surface208of the sidewall206. The ridge202is positioned below the ridge201and tab101when in locked position. Ridge202extends adjacent underneath the bottom edge of the lid skirt113when said lid is on the container. When the lid100and the container200are engaged, the ridge202is positioned immediately below the lower edge113of the skirt108, such that it is difficult to slip an object between the lid100and the container200to pry open the lid100. In some embodiments, the lower edge113of the skirt108is in contact with the ridge202.

In the embodiment shown, the side wall211of the undercut portion520of the container connects the ridge201and the ridge202. In some embodiments, the sidewall211extends downwardly and outwardly from the ridge201such that the ridge202is positioned further away from the sidewall206than the ridge201. The sidewall211encircles the upper perimeter of sidewall206.

In some embodiments, the ridge202of the side wall has an upwardly extending peripheral free end203. The free end203may be in contact with the lower edge113of the skirt108when the lid100and the container200are engaged. The free end203is positioned immediately above and peripherally to the lower edge113of the skirt108. The free end203extends upwardly and outwardly beyond the lower edge113of the skirt108such that the lower edge113of the skirt108is at least partially enclosed by the ridge202and free end203and the sidewall206or211of the container200. In alternate embodiments, to add further tamper protection, free end203could extend upwardly only, rather than outwardly. These configurations may make it difficult to insert an object between the lid100and the container200to pry the lid100off the container200.

In some embodiments, a support rib205extends downwardly along the sidewall206of the container and terminates at a position that is farther away from the lid100than the ridge202such that the rib205supports the ridge202. Such a configuration may enhance the structure and makes it more difficult to push the ridge202toward the sidewall206. In some embodiments, suitable alternative structure is provided to support the ridge202.

In some embodiments, the lid100is made of plastic. In some embodiments, the plastic is injection molded to form the lid100. In some embodiments, the lid is made of metal, plastic, paper, or a combination thereof by any suitable means known in the field.

In some embodiments, the container200is made of plastic. In some embodiments, the plastic is injection molded to form the container200. In some embodiments, the container is made of metal, plastic, paper, or a combination thereof by any suitable means known in the field.

When the lid100engages the container200, it may be difficult or impossible to remove the lid100in the normal usage of the container as described earlier. In some embodiments, a tearable portion114is provided on the lid100as described above. By tearing the tearable portion114along the weakened area, the circumference of the skirt108from which the tabs101extend is no longer a complete circumference such that the remaining portion of the circumference can be pried outwardly to facilitate the removal of the lid100.

In some embodiments, the weakened area extends along the full circumference of the lid such that when the tearable portion is removed all the tabs101are removed, resulting in the removal of the lock formed by the tabs101and container. The skirt108may then be moved outwardly to disengage the lock between the skirt108and the sidewall206.

In some embodiments, the tearable portion114serves as an evidence of tampering. When a user receives the container system10and the tearable portion114has been torn, the user would know that the container with attached lid has been tampered with.

The teeth/tabs101may be connected to the skirt108by frangible lines such that the tab may be biased into the upward locked position, however if the lid100is forcibly removed from the container200without the removal of the tearable portion114, the tabs101are forced downwardly, showing that the container lid upon the container has been tampered with.

In fact, the positioning of the tabs101in the undercut position520, with each said tab101individually abutting the sidewall, immediately below the ridge201, creates a strong locking force by each tab. To pull off the lid without the removal of the tearable portion will result in the tabs101being forceably pressed downwardly by engagement with ridge201at the point of removal, causing a downward fold of the tabs. The embodiments of the present disclosure described above are intended to be examples only. The present disclosure may be embodied in other specific forms. Alterations, modifications and variations to the disclosure may be made without departing from the intended scope of the present disclosure. While the system, devices and processes disclosed and shown herein may comprise a specific number of elements/components, the systems, devices and assemblies could be modified to include addition or fewer of such elements/components. For example, while any of the elements/components disclosed may be referenced as being singular, the embodiments disclosed herein could be modified to include a plurality of such elements/components. While circular containers are shown, the herein invention may be used with square or rectangular containers or other possible shaped. Selected features from one or more of the above-described embodiments may be combined to create alternative embodiments not explicitly described. All values and sub-ranges within disclosed ranges are also disclosed. The subject matter described herein intends to cover and embrace all suitable changes in technology. All references mentioned are hereby incorporated by reference in their entirety.