Plastic and nonmetallic article shaping or treating: processes – With severing – removing material from preform mechanically,... – Making hole or aperture in article
Reexamination Certificate
2000-02-28
2001-05-01
Heitbrink, Jill L. (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
With severing, removing material from preform mechanically,...
Making hole or aperture in article
C264S318000, C249S059000, C215S252000, C425S291000, C425SDIG005
Reexamination Certificate
active
06224802
ABSTRACT:
The present invention relates to tamper-indicating closures, to methods of manufacturing such closures, and to a package that includes such a closure on a container.
BACKGROUND AND OBJECTS OF THE INVENTION
It is conventional to form a tamper-indicating closure having a band connected to the skirt of the closure by integral frangible bridges. The band has a stop element (e.g., a bead or flange) that engages a bead on the container to resist unthreading of the closure, so that removal of the closure ruptures the frangible bridges that connect the band to the closure skirt. U.S. Pat. No. Re. 33,265, assigned to the assignee hereof, discloses a tamper-indicating closure of this character, in which the tamper-indicating band is completely severed from the closure skirt and remains with the container following removal of the closure from the container. Although tamper-indicating closures of this so called “drop-band” type have enjoyed substantial commercial acceptance and success, particularly in the U.S., it is desirable in many situations to provide for removal of the tamper-indicating band with the closure. This is particularly true, for example, where the container is to be reused, or to be recycled for manufacture of new containers. In either of these applications, it would be necessary to remove a tamper-indicating band that remains on the container after the closure has been removed.
U.S. Pat. Nos. 4,432,461 and 5,295,600, both assigned to the assignee hereof, disclose tamper-indicating closures in which the tamper-indicating band remains with the closure following removal from the container. In each of these patent disclosures, the tamper-indicating band is coupled to the skirt of the closure by a plurality of bridges, one of which is sized so as to be non-frangible in normal use. In U.S. Pat. No. 4,432,461, both ends of the tamper-indicating band are connected to the closure skirt by a bridge of enlarged circumferential and/or radial dimension, so that both ends of the band remain connected to the skirt following rupture of the other bridges and removal of the closure from the container. In U.S. Pat. No. 5,295,600, an interrupted circumferential scoreline extends around the skirt and band to provide the frangible bridges between the skirt and band, and to provide the enlarged bridge between the skirt and band at the point of interruption of the scoreline. A pair of axial scorelines are provided in the tamper-indicating band circumferentially adjacent to the enlarged bridge. Thus, one end of the tamper-indicating band remains connected to the closure skirt following rupture of the frangible bridges and removal from the container, while the opposing end of the tamper-indicating band is free of connection to the skirt forming a so-called “pigtail” band.
In manufacture of tamper-indicating closures of the type disclosed in U.S. Pat. No. 5,295,600, it is necessary in the manufacturing tooling to orient the closure with respect to the score tooling so that the vertical or axial scores are properly positioned with respect to the interrupted circumferential score. It is therefore one object of the present invention to provide a pigtail-type tamper-indicating closure and method of manufacture in which the need for axial scores in the tamper-indicating band is eliminated, and in which there is no requirement or need for orienting the closure during the circumferential scoring operation. Another object of the present invention is to provide a tamper-indicating closure and method of manufacture in which the closure is adapted for use either as a pigtail-type tamper-indicating closure in which the tamper-indicating band is removed from the container with the closure, or as a drop-band type tamper-indicating closure in which the band remains on the container after removal of the closure.
SUMMARY OF THE INVENTION
A tamper-indicating closure of integrally molded plastic construction in accordance with a presently preferred embodiment of the invention includes a base wall having a peripheral skirt with internal threads for engaging external threads on the finish of a container. A tamper-indicating band is connected to the lower or free edge of the skirt by a plurality of circumferentially spaced integral bridges. At least one of the bridges has a greater circumferential dimension than other of the bridges. A thin integral membrane is disposed in the band immediately circumferentially adjacent to the one bridge, and extends both axially and circumferentially of the band. A stop element (e.g., a flange) is positioned on the band for engaging a bead on a container to inhibit removal of the closure, such that the membrane and the other bridges rupture upon removal of the closure but the band remains connected to the closure by the one bridge of enlarged circumferential dimension. Provision of the thin membrane during the closure molding operation thus provides for rupture of the free end of the band to form the pigtail band configuration upon removal from the container without axial scoring or other secondary manufacturing operations that would require controlled orientation of the closure.
In accordance with another aspect of the present invention, there is provided a tamper-indicating closure of integral as-molded plastic construction, which comprises a base wall having a peripheral skirt with internal threads for engaging external threads on the finish of a container. An annular tamper-indicating band integrally axially extends from the skirt, and a plurality of circumferentially spaced bridges are molded on an internal face of the skirt and extend axially into the band. At least one of the bridges has a greater circumferential dimension than other of the bridges but a lesser axial dimension into the band. A thin integral membrane is molded into the band circumferentially adjacent to the one bridge, and extends both axially and circumferentially of the band. A stop flange on the band engages a bead on the container to inhibit removal of the closure from the container. The closure is thus adapted to be externally scored to separate the band from the skirt, with the score being spanned by at least some of the bridges. When the circumferential score is positioned axially to engage the one band of enlarged circumferential dimension, the other bridges and the membrane are ruptured upon removal of the closure from the container, such that the closure is of a type adapted to provide a pigtail-type tamper-indicating band that is removed with the closure. When the circumferential score is positioned axially so as not to intersect or engage the one bridge of enlarged circumferential dimension, the closure is of a drop-band type in which the band is completely severed from the closure upon removal of the closure from the container, and remains with the container following removal of the closure. Thus, either a pigtail-type closure or a drop-band-type closure may be provided employing the same mold tooling and by adjustment of the position of the circumferential score into the closure skirt.
In the preferred embodiments of the invention contemplating a pigtail-type tamper-indicating closure, one, two or four circumferentially uniformly spaced bridges of enlarged circumferential dimension are provided for forming closures having one, two or four pigtails. A thin integral membrane is molded into the tamper-indicating band circumferentially clockwise adjacent to each of the enlarged bridges. The stop flange that extends from the tamper-indicating band has a circumferential interruption axially aligned with each of the integral membranes for both weakening the stop flange to facilitate rupture upon removal of the closure from the container, and to provide a gap through which mold tooling may pass for formation of the membrane(s) during and as part of the molding operation. The circumferential dimension of the enlarged bridge(s) may be between 23° and 90°, depending upon the number of bridges in the closure.
A method of making a plastic tamper-indicating closure in accordance with another aspect of the pres
Gregory James L.
Kurtz Stephanie L.
Heitbrink Jill L.
Owens-Illinois Closure Inc.
LandOfFree
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