Bottles and jars – Closures – Frangible member or portion
Reexamination Certificate
1999-03-08
2001-07-17
Shoap, Allan N. (Department: 3727)
Bottles and jars
Closures
Frangible member or portion
C215S317000, C215S321000, C215S901000
Reexamination Certificate
active
06260721
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a plastic cap having a low cap height and a reduced resin weight as well as excellent sealing reliability, easy openability, and tamper-evidence.
2. Prior Art
Because resin caps can be produced by integral molding and have excellent moldability and flexibility, they can be fixed to a mouth portion of a container by a capping operation, and have been used widely in various forms.
Various resin caps having excellent openability which have excellent sealability, and can be removed easily from a mouth portion of the container without using a tool have been proposed. For example, Japanese Laid-Open Patent Publication No. 58719/1997 describes the structure of a synthetic resin cap comprising a mouth portion of a bottle, two circumferential grooves provided along its outer peripheral portion and the cap mounted in engagement with the top of the mouth portion of the bottle and the inner surface of the mouth of the bottle. This cap is a one-piece cap composed of an upper closure, a tamper-evident band and a side score portion which connects the lower end of the upper closure portion to the upper end of the tamper-evident band on a circumference.
The above prior art is significant because it provides a plastic cap openable by a hand without any particular tool such as a cap opener, and having a function of preventing a fraudulent act. However, two-staged engagement jaw portions are present for holding a tamper-evident property and for holding resealing on the outer circumference of a container, and therefore two-staged protrusion portions exist on the cap side. Because of such portions, there is an inconvenience that the cap height becomes high, and the resin weights of the mouth portion of the container and the cap become high.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a plastic cap having a low cap height and a reduced weight of a resin and maintaining excellent sealing reliability, and excellent openability and tamper-evident property.
Another object of this invention is to provide a plastic cap in which by a one-stage engaging jaw portion present in the neck portion of a container, tamper-evident property and resealing property are held.
There is provided a plastic cap comprising a top plate provided with a sealing portion to be engaged with a mouth of a container, a skirt extending perpendicularly from the top plate, and a tear-off portion arranged around the skirt and defining an upper closure portion for resealing and a lower opening band, wherein in an inner surface of the skirt, at an upper position than the tear-off portion, a diametrically inwardly-directed protrusion which is engaged with a jaw of the container is formed peripherally intermittently, simultaneously, at a lower position than the tear-off portion, a flap piece whose tip portion is engaged with the jaw of the container is formed peripherally intermittently, and the protrusion and the flap piece are formed at least alternately in most of the peripheral direction.
In the cap of this invention, the following requirements should be included preferably.
1. The flap piece is provided via a continuous base portion having a small width and projecting diametrically inwardly from the inner surface of the skirt.
2. In the inner surface of the skirt above the root of the above-mentioned flap piece, a concave portion for the flap (flap-concave portion) which receives the upwardly bent flap piece is formed.
3. The flap piece is provided so that its thickness is increased from the root to tip.
4. The opening band is provided with a notched portion or a weakened portion which extends perpendicularly or obliquely and reaches the tear-off portions and a diametrically outwardly projecting opening-starting tab is provided in a portion of the opening band adjacent to the notched portion or the weakened portion.
5. The tear-off portion is composed of a groove (having a thin wall thickness) formed peripherally, or a peripheral gap formed in a lower portion of the protrusion. For example, a perpendicularly extending bridge and a groove are arranged in the lower portion of the protrusion, and the peripheral gap is formed so that at least a part of the bridge is left.
The plastic cap of this invention comprises a top plate provided with a seal portion engaged with the mouth of a container such as a bottle, a skirt extending downwardly from the top plate and a tear-off portion arranged around the skirt and defining an upper closure portion for resealing and a lower opening band. This plastic cap is characterized in that in the inner surface of the skirt, (1) at an upper position of the tear-off portion, a diametrically inwardly-directed protrusion (engaging protrusion) which is engaged with a jaw of the container is formed peripherally intermittently, (2) at a lower position than the tear-off portion, a flap piece whose tip portion is engaged with the jaw of the container is formed peripherally intermittently so that at least on most of the peripheral direction, the engaging protrusion and the flap piece are arranged alternately.
In the cap of this type, it is generally necessary that the resealing upper closure portion should be provided with an engaging portion for the container to hold resealability, and the opening band should be provided with an engaging portion for the container to hold tamper-evident property. Since in this invention a flap piece is used as the engaging portion for holding tamper-evident property, an advantage is that the mouth of the container can be easily inserted into the cap in a state in which the flap piece is upwardly bent at the time of capping, and that the engaged position by the tip of the flap piece can be established at an upper position than the opening band.
The engaging protrusion of the upper closure portion is arranged peripherally intermittently, the flap piece of the opening band is arranged intermittently, and the engaging protrusion and the flap piece are arranged alternately in most of the peripheral direction, that is to say, a bent flap piece is positioned at the vacant position free from the engaging protrusion. Hence, it is possible to engage the engaging protrusion and the tip portion of the flap piece simultaneously with a single engaging jaw of the container.
For this reason, according to this invention, one-stage engaging jaw at the neck of the container can hold tamper-evident property and resealing property. Thus, the length of the neck of the container can be shortened and the resin weight of the container can be reduced. The resin weight of the cap can be reduced, and marked advantages can be obtained in that the effective utilization of resources can be realized and the cost can be reduced.
Furthermore, the upper closure portion for resealing and the opening band are in a state of integration until cap-opening from capping. Thus, since both of the engaging protrusion and the tip portion of the flap piece are engaged with the engaging jaw, an upward or diametrically inward pressure for sealing can be increased and sealing can be performed with high reliability, and it is possible to hold tamper-evident property easily. As already pointed out, since the flap pieces are arranged intermittently, the bending of the flap pieces upwardly can be performed easily, and moreover, the capping operation is easy.
The opening of the container is carried out by tearing the opening band peripherally at the tear-off portion, removing the opening band in the stage of being integral with the flap piece, and then pushing up the upper closure for resealing. At this time, the engaging protrusion of the upper closure should climb over the engaging jaw of the container, but since in this invention, the engaging protrusion is formed peripherally intermittently, the force required to climb over the engaging jaw can be set at a lower level, the openability of this cap is excellent. Furthermore, since an engaging protrusion for the flap piece is not provided below the jaw of the container, a space can
Kubo Tateo
Kumata Mitsuo
Ohmi Hidehiko
Eloshway Niki M.
Fulbright & Jaworski L.L.P.
Japan Crown Cork Co. Ltd.
Shoap Allan N.
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