TECHNICAL FIELD

The present invention relates to closures for containers. More particularly, the present invention related to a tethered plastic closure that is used to maintain connection of the closure to the container.

BACKGROUND OF THE INVENTION

In the field of liquid packaging, it is very common to seal the aperture of a container with a cap, usually made from plastic material. Such container is usually a plastic or glass bottle, filled with a liquid.

The cap has a tubular shape closed at its top edge. The cap comprises a closure shell, having a top wall surrounded by a skirt, and a tamper band attached to the bottom edge of the skirt through breakable bridges. The bridges are distributed around the closure shell and the tamper band. Moreover, the bridges are made when molding the cap or after through a cutting or a slitting step.

Usually the bottle neck comprises outer fixation feature, such as thread(s) for screw type cap or annular fixation rings for snap type cap, to secure the cap on the bottle neck.

As known, according to screw type cap, the closure shell comprises inner thread(s) arranged inside side walls. The bottle neck fixation feature comprises outer thread(s). Such combination of outer and inner thread(s) allows the cap to be screwed on a bottle neck to seal it and unscrewed for bottle entirely opening. According to another known embodiment, a snap type cap comprises inner annular area and the bottle neck fixation feature comprises outer fixation ring, in order to slot the cap in force on the bottle neck. Moreover, a snap type cap comprises a closure shell with a movable sealing roof from a closure position to a part opening, and reversely. The roof may be separating upon opening or may be connected to the closure shell.

In a bottle sealing position of the cap, the tamper band is secured around the bottle neck through inner tamper band retaining features or through the tamper band diameter being smaller than a diameter of a tamper evident ring of the bottle neck.

Usually, the closure shell and/or the roof is removable. During bottle opening, the bridges form a weakness line and are teared apart from the closure shell and/or the roof, so it is separated from the bottle. The weakness line is teared, when user unscrews the closure shell of the cap or when user lifts the roof by tilting.

There is a recycling risk with separable closure shell and/or roof as consumers may not always screw or snap back the closure shell and/or the roof onto the bottle neck once empty. The cap may result to be heading to the trash bin or worse landfill and it is not good in view of the environmental considerations.

A solution consists in linking the closure shell to the tamper band secured on the bottle neck, so the closure shell stays attached to the bottle after bottle opening. Such an attached cap is so called a “tethered cap”.

As described in US 9,010,555 a plastic screw cap comprises a peripheral strip between a tamper band and a closure shell. Such peripheral strip is linked at the tamper band through a bottom weakness line and at the closure shell through a top weakness line. The bottom weakness line and top weakness line are parallel and extend almost the entire periphery of the cap in order to manage a hinge or two hinges close together. When unscrewing the cap, the bottom weakness line and the top weakness lines tear apart but the two hinges hold the closure shell on the tamper band. The closure shell becomes unremovable and it toggles around the hinges beside of the cap secured on the bottle neck.

As proposed in US 8,490,805 a plastic screw cap comprises an helicoidal strip between a tamper band and a closure shell. Such helicoidal strip is obtained by cutting the tamper band around the cap. Therefore, the outer wall of the tamper band is placed against a blade and the cap is moved in rotation relative to the blade according to an angular stroke greater than an entire turn, so more than 360°. Moreover, during its rotation the cap is being moved in an axial movement relative to the blade. Thus, the cut line forms an helicoidal weakness line which remains attached at one end to the tamper band and at its opposite end to the closure shell after opening.

A problem with the known tethered caps is to make sure that the weakness top ends of the strip remain attached to the closure shell. Thus, after opening, the strip ends can easily be broken and the closure shell is not linked anymore to the bottle neck.

SUMMARY OF THE INVENTION

An object of the present invention is to improve a tethered plastic cap wherein its closure shell remains attached to its tamper band after bottle opening through at least one strip. The strip(s) is linked at its bottom to the tamper band through at least a hinge and/or the top to the closure shell.

To that effect, at least one end of a strip linked to the closure shell is shaped to avoid unintentional breaking by the consumer. The shape of said strip end is especially designed in order to avoid the propagation, during and after the opening of the closure shell, of the tear of the top and/or bottom weakness line at the level of said end.

In some embodiments, each weakness line has at least two side ends, which, before the cap is removed from a container, constitute side edges of the weakness lines, and after the cap is open constitute strip ends, and at least the side edge of the weakness line corresponding to that strip end, from which the propagation of the tear should be avoided, is inclined related to the direction of orientation of said weakness line so that, when the cap is open and the bridges have been broken, the strip end comprises a part, corresponding to said side edge, which is not aligned with the rest of the strip.

In some embodiments, each bottom strip end comprises on the side of the bottom weakness line a portion with a less thickness material than the material of the tamper band. In other words, each hinge length is increased where each strip end is connected, with a material which thickness allows itself to tear without breaking. So, such portion only allows the bottom weakness line to propagate to a predetermined limit without breaking the strip.

Thus, when tearing the bottom bridges of the bottom weakness line until they break, the tear does not extend along the strip bottom end, thanks to the its portion of the hinge. In some embodiments, the solution is adapted to the top end of the strip, with such portion with a less thickness material than the thickness of the material of the closure shell.

In some embodiments, the bottom weakness line includes at least an offset located at least at one side of the hinge.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood on reading the following description given merely by way of examples and with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic lateral view of a first embodiment of a tethered cap according to the invention, in a closed position; FIG. 2 is a diagrammatic lateral view of the first embodiment of the tethered cap, in a partially opened position;

FIG. 3 is a diagrammatic lateral view of a second embodiment of a tethered cap according to the invention, in a closed position; and

FIG. 4 is a diagrammatic lateral view of the second embodiment of the tethered cap, in a partially opened position.

FIG. 5 is a diagrammatic lateral view of another embodiment of a tethered stopper according to the invention, in a closed position;

FIG. 6 is a diagrammatic lateral view of the stopper in FIG. 5 in a partially opened position; and

FIG. 7 is a diagrammatic lateral view of another embodiment of a tethered stopper according to the invention, in a closed position;

FIG. 8 is a diagrammatic lateral view of the embodiment of the tethered stopper, in a partially opened position;

FIG. 9 is a diagrammatic lateral view of another embodiment of the tethered stopper; and

DETAILED DESCRIPTION

The invention relates to a tethered plastic screw cap 1, for closing a bottle neck. The cap 1 is integrally made of one plastic piece by a molding fabrication step. Other parts or elements of the cap 1 can be further created into the entire plastic piece through a cutting or slitting step.

The cap 1 comprises a closure shell 2 and underneath a tamper band 4. The limit between the closure shell 2 and the tamper band 4 is called either bottom edge of the closure shell or top edge of the tamper band. The tamper band 4 and the closure shell 2 are linked together as explained thereafter. The cap 1, on an inner surface, includes fixation features, such as thread(s), designed to cooperate with outer complementary fixation features made on the bottle neck.

As shown on FIGs. 1 and 3, before opening, the cap 1 comprises at least one strip 6, managed in a circumferential portion of the cap located between the bottom edge of the closure shell 2 and the top edge of the tamper band 4.

In some embodiments, the cap 1 comprises two strips 6 that maintain the closure shell attached to the tamper band, once the container has been opened. The strip(s) 6 are each arranged on circumferential portion of the cap located between the bottom edge of the closure shell 2 and the tamper band 4. By “arranged on circumferential portion of the cap located between the closure shell 2 and the tamper band 4”, it is meant that the developed length of the strips is less than the whole circumference of the bottom edge of the closure shell 2 (or of the top edge of tamper band 4), so that it remains a part of the circumference wherein the closure shell 2 and the tamper band 4 are not separated by a strip but by a weakness line, as explained below. The two strips 6 are oppositely managed regarding a diameter of the cap 1.

The cap 1 includes a bottom weakness line 8 that is separably linked through bottom bridges 9 to the top edge of the tamper band 4 and to the bottom edge of each strip 6. The bottom weakness line 8 is also separably linked through bottom bridges 9 to the top edge of the tamper band 4 and to the bottom edge of the closure shell 2, in those portions of the circumference that are not facing a strip 6. The bottom weakness line 8 runs on the whole periphery of the top edge of the tamper band 4, with the exception that this weakness line 8 is interrupted by one and preferably two portions, which, once the cap has been opened, constitute hinges 12 between the tamper band 4 and the rest of the cap, as shown on FIGs. 2 and 4. More precisely, these portions are such that the hinges 12 are spaced apart through a hollow line or through an area of less thick material. Each hinge 12 links the tamper band 4 to one respective strip 6, more precisely to one end 15 of the strip 6, constituting a so-called bottom end 15, when the cap is open (FIGs. 2 and 4).

The cap 1 also includes a top weakness line 10, separably linked through top bridges 11 to the bottom edge of the closure shell 2 and at least to the top edge of each strip 6. The ends 13 of the top weakness line 10 correspond to the top end 13 of the strips 6, when the cap is open (e.g., Figures 2 and 4). The top weakness line 10 extends on a circumferential part of the skirt. In some embodiments, the length of the top weakness line 10 extends less than the half perimeter of the skirt. In other embodiments, the length of the top weakness line 10 extends more than half of the perimeter of the skirt.

As such, when unscrewing the closure shell 2, the bottom bridges 9 and the top bridges 11 are stretched until they break, the closure shell 2 remaining attached to each strip 6 through its top end 13, the strips 6 remaining attached at their opposite bottom end 15 to the tamper band 4 (as can be seen on FIGs. 2 and 4).

In some embodiments, as illustrated in FIG. 1, the top end 13 of each strip 6 comprises an edge 14, which, before the bridges 9, 11 of the weakness lines 8, 10, are broken, constitutes an end of the top weakness line 10, the edge 14 being angled (e.g., slanted at include or decline) related to the orientation of the top weakness linelO. Especially, the top weakness line horizontally extends, such as shown through dot lines in the embodiment in FIG. 1. As such, the edge 14 is not horizontal and is not aligned with the horizontal plane of the top weakness line 10. Therefore, when unscrewing the closure shell 2 and stretching and tearing the top bridges 11 until they break, the different orientation of edge 14 compared to that of the top weakness line 10 changes the force applied at the top end 13 of each strip 6. It is the same once the closure shell 2 is totally unscrewed, remaining attached through each strip 6: the force is distributed along the inclined edge 14.

In some embodiments, the edge 14 of each strip 6 angularly extends from 10° to 90° relative to the top weakness line orientation.

In some embodiments, the edge 14 of each strip 6 upwardly extends relative to the top weakness line 10. The edge 14 offsets into the closure shell 2, so the force distributed along each strip 6 is oriented to the closure shell 2, instead of top end 13 of the strip 6, which is less resistant.

In some embodiments, as illustrated in FIGs. 1 and 2, the edge 14 is linear. In other embodiments, as illustrated in FIGs. 3 and 4, the edge 14 is curved. In some curved embodiments, the edge 14 is concave. So, the edge 14 is hollowed facing the top weakness line 10.

In some embodiments, the ends 14 of the weakness line and, hence, the corresponding edges 14 of each strip 6 are made by molding, at the time when the cap 1 with the weakness lines and the bridges are molded. According to another embodiment, each edge 14 and the bridges are made by cutting or slitting, so after molding the cap 1.

Each strip 6 is linked to a respective hinge 12 at a bottom end 15 thereof, when the cap is open. Each bottom end 15 comprises a bottom edge 16 located at the end of the bottom weakness line 8. The bottom edge 16 can be similar to the top edge 14, which means that before the bridges 9, 11 of the weakness lines 8, 10 are broken, the edge 16 constitutes an end of the bottom weakness line 8.

In some embodiments, similar to the edge 14, the bottom edge 16 can be angled (e.g., slanted) related to the orientation of the bottom weakness line 8. The bottom edge 16 can angularly extend from 10° to 90° relative to the bottom weakness line 8. Each bottom edge 16 can be curved and/or concave. Each bottom edge 16 can be made by molding or by cutting or slitting.

In some embodiments, the stopper 1 includes two hinged areas 18, each linked to the tamper band. In some embodiments, as illustrated in FIGs. 5-6, the hinges are spaced apart through a hollow line or area. Moreover, the top weakness line 10 is separably linked through the top bridges to the bottom edge of the closure shell 2 and to the top edge of each hinged area 18.

Each hinged area 18 includes a hinge 12 and a portion 20 having a material thickness that is diminished (e.g., thinned) when compared to the thickness of material for the hinge 12. I some embodiments, each thinned portion 20 angularly extends from 5° to 30° relative to each hinge 12. This thinned area (i.e., portion 20) is designated in the figures as a dotted line.

The thinned portion 20 is configured to be weaker (e.g., withstand less force) than the hinge 12, in order to direct propagation of a tear towards the hinge 12 instead of another portion of the hinged area 18. For example, the thinned portion 20 is intended to direct tear propagation away from the bottom end of strip 6 located closest to the hinged area 18.

According to another embodiment (not shown) in a similar way, each strip 6 is linked through a top end to the closure shell 2, and the top end of each strip 6 would include a thinned portion of material to direct tear propagation away from the top end of the strip 6.

In some embodiments, as illustrated in FIG. 7, the bottom weakness line 8 comprises one or more offsets 22, located at least at one side of a hinge 12. As illustrated, the offsets 22 located on either side of one hinge 12. Each offset 14 is downwardly managed into the tamper band 4. In other words, the offset 22 is made of a hollow managed into the height of the tamper band 4. Each offset 22 vertically may for example extend from 5 % to 30% relative to the height of the tamper band 4.

In some embodiments, such as when the stopper 1 comprises two separated hinges 12, the bottom weakness line 8 comprises two offsets 20 located at the left and the right of both hinges 12.

In some embodiments, such as shown in FIGs. 7-8, each offset 22 is directly linked to the bottom weakness line 8. In other embodiments, such as shown in FIG. 9, each offset 22 is separated from a portion of the bottom weakness line 8, through a wall 24 with a less thickness or through bridges.

In the illustrated embodiment, the bottom edge of each offset 22 is horizontal. However, in some embodiments, the bottom edge of each offset 22 is inclined relative to a horizontal plane, decreasing, from top to bottom of the tamper band 4, in the direction of each hinge 12.

In the illustrated embodiment, the offset opposite edge relative to each hinge 12 is vertical. However, in some embodiments, the offset opposite edge relative to each hinge 12 is inclined relative to a vertical plane.

According to an embodiment, each offset 22 is angularly managed along the bottom weakness line 8 from a hinge 12 to the nearest bottom bridge relative to the hinge 12. The offset 22 can extend angularly from 5° to 90° on a side of each hinge 12.

For example, the offset 140 extends 15° on either side of the hinge 12.

Each offset 22 is made when molding the stopper or after molding, through a cutting or slitting operation.

So the stopper 1 according to the invention comprises at least one offset 22 located along the last segment close to the attached bottom ends of the strip 6, in order to increase the tether width in this location. The strip bottom attachment section will become thicker and thus harder to separate from the tamper band 4, when a consumer removes the closure shell 2.