|Publication number||US20060163265 A1|
|Application number||US 10/522,517|
|Publication date||Jul 27, 2006|
|Filing date||Jun 20, 2003|
|Priority date||Aug 1, 2002|
|Also published as||WO2004013010A1|
|Publication number||10522517, 522517, PCT/2003/949, PCT/CA/2003/000949, PCT/CA/2003/00949, PCT/CA/3/000949, PCT/CA/3/00949, PCT/CA2003/000949, PCT/CA2003/00949, PCT/CA2003000949, PCT/CA200300949, PCT/CA3/000949, PCT/CA3/00949, PCT/CA3000949, PCT/CA300949, US 2006/0163265 A1, US 2006/163265 A1, US 20060163265 A1, US 20060163265A1, US 2006163265 A1, US 2006163265A1, US-A1-20060163265, US-A1-2006163265, US2006/0163265A1, US2006/163265A1, US20060163265 A1, US20060163265A1, US2006163265 A1, US2006163265A1|
|Inventors||Rick De Candido|
|Original Assignee||Stack Teck Systems Ltd.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (9), Classifications (31), Legal Events (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a continuation-in-part of International Application No. PCT/CA03/00055, filed Jan. 17, 2003, and also a continuation-in-part of International Application No. PCT/CA02/01311, filed on Aug. 26, 2002, and also claims the benefit of U.S. Provisional Application No. 60/399,731, filed Aug. 1, 2002.
This invention relates generally to injection moulded containers and their lids. More specifically this invention relates to tamper evident lids which may be applied to standard containers.
Tamper evident (TE) features are very important in the packaging industry. Unfortunately, packages having tamper evident features generally require specific container and lid designs making the container and the lid a unique combination. A disadvantage to this type of design is that expensive moulds are required not only for the container but for the lid and the moulds are often limited in design to a single product.
Many applications in the food packaging industry currently use “standard” container sizes, which can be purchased from a multitude of suppliers. The containers are generally filled with packaging machinery adapted to those container sizes. If special containers and lids are to be used, it may be necessary to install additional machinery in a filling line to accommodate assembly limitations caused by the special tamper evident containers.
U.S. Pat. No. 5,540,342 by Rathbun describes a lid having a dual locking system to retain the lid on a container. The lid uses a purality of primary beads and secondary locking ribs to retain the lid on the container.
However, one disadvantage of Rathbun's lid is that the locking ribs are completely removed from the lid once the lid is initially from the container, thus removing all visual evidence of the released locking ribs.
It is an object of the present invention to provide a tamper evident lid which may be used with a standard container. Preferably the lid may be mounted onto such a container using conventional packaging equipment currently available in most automated filling lines.
A tamper evident lid is provided for mounting over an opening of a container having sidewalls with a lip extending outwardly therefrom to define an opening. The lid has a base, a rim extending about the base for receiving the lip and at least one resiliently flexible finger extending radially inwardly from the rim for engaging the lip. Each finger has a length exceeding the distance between an inside of the lip and the sidewall and extends towards the base when the lid is mounted on the container. At least one frangible membrane is formed in the rim and associated with at least one of the fingers for facilitating tearing of the rim to disengage the associated finger(s) from the lip thereby enabling removal of the lid from the container while leaving evidence of removal by way of a torn frangible membrane.
The rim may have an upper end adjacent the base and a lower edge distal the base with the frangible membrane extending from the lower edge toward the upper end.
A respective of the frangible membranes may be disposed on opposite sides of at least one finger. Alternatively, at least one pair of fingers may be provided with each one of the pair of fingers disposed on an opposite side of the frangible membrane.
The frangible membrane may extend to a membrane hinge formed in at least one of the rim and the base. The membrane hinge may be positioned to facilitate disengagement of the associated finger from the lip upon tearing of the frangible membrane.
The associated finger may be disposed between the membrane hinge and the lower edge.
The frangible membrane may extend to at least one membrane hinge formed in the rim. Each such membrane hinge may extend from the lower edge toward the base with an associated finger disposed in any area bordered by the frangible membrane, a membrane hinge and a lower edge.
A pair of fingers may be disposed between a pair of membrane hinges extending from the lower edge toward the base. A frangible membrane may extend from the lower edge to each one of the pair of the membrane hinges so that each of the fingers is disposed in an area bordered by at least part of the frangible membrane, one of the membrane hinges and the lower edge.
A pair of radially spaced apart frangible membranes may be provided with at least one of the resilient fingers disposed therebetween. A membrane hinge may extend across the base between the frangible membranes to facilitate disengagement of the fingers from the lip upon tearing of the frangible membranes by bending a portion of the base away from the lip.
A plurality of fingers may be disposed between the frangible membranes of the embodiment described in the preceding paragraph.
At least one of the fingers may be a webbed finger having a web defined by a reduced thickness region extending toward the rim from a lip engaging end of the webbed finger which is distal the rim.
Each webbed finger may be provided with a passage therethrough in the form of a window to promote drainage of fluid trapped between the webbed finger and the rim.
The fingers may be of various profiles including rounded, parallel faced straight, tapered narrowing toward the rim and tapered narrowing toward the rim with a scallop facing the container at an outer end thereof distal the rim.
Each finger may be curved in a direction generally corresponding to a curvature of the container to provide a lengthened contact zone with the lip.
The rim may be a recess extending from the fingers to the lower edge to accommodate the fingers thereby facilitating stripping of the lid in an injection moulding process.
The fingers may extend from the lower edge of the rim.
At least one pull tab may extend from the lower edge of the rim to facilitate tearing of at least one of the frangible membranes.
A stacking ring may extend about the base away from the rim to engage the lower edge of an adjacent tamper evident lid when the lids are stacked in order to resist lateral shifting therebetween. The stacking ring may be segmented or continuous.
A chamfer may extend into the rim from the lower edge at the juncture of the frangible membranes and the lower edge to avoid a sharp corner at the juncture upon tearing of the frangible membrane.
Preferred embodiments of the present invention are described below with reference to the accompanying illustrations in which:
A tamper evident lid (“lid”) according to the present invention is generally illustrated by reference 10 in the accompanying illustrations. The lid 10 has a base 12 and a rim 14 which extends about the perimeter of the base 12.
Discrete fingers 20 extend from an inside of the rim 14. The fingers extend radially inwardly and toward the base 12 (inwardly and upwardly as illustrated in the figures).
The lid 10 is intended for mounting over a “standard container” 13 as illustrated in
Each of the fingers 20 has a length which exceeds the distance or “gap” between the inside of the rim 14 and the outside of the sidewall 30 as illustrated at reference 41. The length of the fingers 20 exceeds the breadth of the gap as illustrated by arrow 44. Accordingly, when the lid 10 is forced over the lip 32, the fingers 20 flex toward a retracted position against the inside of the rim 14. Once fully past the lip 32, the fingers flex inwardly, away from the rim 14, to rest against the sidewall 30. The direction of this spring bias is indicated by reference 31. In order to enable the flexing of the fingers 20, the material of the lid 10 must have a desired degree of resiliency which is characteristic of the type of plastics typically used for such lids (polyethylene for example). Basically the fingers 20 must be able to flex without breaking off.
Once in place, removal of the lid 10 from the container 13 is resisted by the fingers 20 engaging an underside 36 of the lip 32. As the ends of fingers 20 rest against the sidewall 30, the fingers 20 can rely on the sidewall 30 for support and accordingly a tremendous amount of strength is not required from the fingers 20. This proves advantageous in stripping the lid 20 from an injection moulding assembly, as discussed below.
To either side of the fingers 20 is a frangible membrane 22 (see
A membrane hinge 26 (see
Alternatively the membrane hinge 26 may be substituted for a further frangible membrane 22 to allow complete removal of the tear tabs 24.
An inwardly extending rib 50 (see
Preferably the rim 14 at the tear tabs 24 is thinner below the finger 20 (distal the base 12) than above the finger 20 (proximal the base 12) by an amount corresponding to the thickness of the fingers 20. This forms a recess 28 (see
After injection and solidification of a molten resin to form the lid 10, the formed lid 10 will typically shrink onto the moving core poppet 102 and core base 104 enabling the lid 10 in combination with the core poppet 102 and core base 104 and stripper ring 110 to be moved away from the cavity 100 as the mould is opened. Next, the core poppet 102, stripper ring 110 and lid 10 move away from the core base 104 toward the cavity 100. The core poppet 102 stops moving and the stripper ring 110 pushes the lid 10 off of the poppet 102.
As shown by dashed lines in
The fingers 20 will generally retain enough “memory” to resiliently flex toward their original position as the formed lid 10 cools after stripping.
Alternatively the fingers 20 may be configured to cool so as to point away from the base 12 (“down”) and be pushed into an “upwards” position mechanically after moulding.
Although six tear tabs 24 are illustrated, other numbers are possible. Generally it is expected that six to eight will prove an optimal compromise between security and effort to remove the lid 10. It may be possible to have as few as one tear tab 24 if it is broad enough to retain the lid 10 on the container 13. Two or more is preferable. It is generally not necessary to lift away all of the tear tabs 24 for removal of the lid 10. Lifting away the tear tabs 24 about half the perimeter and sometimes less of the lid 10 will generally prove sufficient to enable removal of the lid 10 when installed on the container 13.
As illustrated in
In some instances it may be desirable to avoid the use of a membrane hinge 26 or to provide one with significant restorative force characteristics. This might for example be the case where it is desired for the fingers 20 to participate in “locking” the lid 10 to the container lip 32 upon reapplication of the lid 10. Such an arrangement is illustrated in
As illustrated in
The wider span fingers 20 of the
As illustrated in
A variety of configurations for the fingers 20 may be utilized.
A continuous stacking ring 46 can be easier to manufacture. To provide a continuous stacking ring 46 the membrane hinge 26 may be located on the rim 14 below the base 12.
Alternatively, as shown toward the right of
As a safety precaution it is desirable to avoid sharp edges upon tearing of the frangible membranes 22. One way of achieving this, as illustrated in
Accordingly, the lid 10 of FIGS. 18 to 22 includes an offset tab 24 (and optional offset sidewall 25) configuration for providing an offset hinge 64 at the point of offset. The extending portions 60 overlap the first tab portions 24 a to interrupt the rupture of the frangible membranes 22, such that the membrane 22 tearing is inhibited from damaging the integrity of the rim 14 between the ribs 50 and the base 12. The thickness of the ribs 50 and corresponding extending portions 60 are sufficient to resist tear continuation of the membrane 22 past the ribs 50, and therefore restrict or otherwise localise separation of the tabs 24 from the sidewall 25 primarily to the second tab portions 24 b. Maintaining integrity of the rim 14 near the base 12 helps to provide a resealing capability to the lid 10 once opened.
The above description is intended in an illustrative rather than a restrictive sense. Variations may be apparent to those skilled in the relevant art without departing from the spirit and scope of the invention as defined by the claims set out below.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7694837 *||May 17, 2005||Apr 13, 2010||Huhtamaki, Inc.||Tamper evident container lid|
|US7712626||Jul 30, 2009||May 11, 2010||Pwp Industries||Edge-tearing tamper evident container|
|US7938286 *||Feb 13, 2007||May 10, 2011||Gateway Plastics, Inc.||Container system|
|US7992743||Jan 20, 2009||Aug 9, 2011||Pwp Industries||Edge-tearing tamper-evident container|
|US8251249||Feb 16, 2009||Aug 28, 2012||Pwp Industries||Hangable tamper resistant packaging system|
|US8322555||Oct 14, 2008||Dec 4, 2012||Pwp Industries, Inc.||Resealable tamper-evident container assembly and lid|
|US8733550 *||Mar 9, 2012||May 27, 2014||Wki Holding Company, Inc.||Nesting container lids with snap on wings|
|US20140061215 *||Nov 5, 2013||Mar 6, 2014||Rich Cup Bio-Chemical Technology Co., Ltd.||Lid|
|WO2009046079A1 *||Oct 1, 2008||Apr 9, 2009||Glenn A Caspary||Snap-over port cap|
|U.S. Classification||220/784, 220/266|
|International Classification||B65D43/02, B29C45/00, B29C45/44, B65D41/16, B65D41/32|
|Cooperative Classification||B65D41/3423, B65D2543/00694, B65D2543/00629, B65D2543/00685, B65D2543/00768, B65D2543/00194, B65D2543/00527, B29L2031/565, B29C45/0081, B65D2543/00657, B65D2543/00092, B29C45/4407, B65D2543/00759, B65D2543/00805, B65D2543/00379, B65D43/0262, B65D2543/00796, B65D2101/003, B65D2543/00537, B65D2543/00296|
|European Classification||B29C45/44B, B29C45/00K, B65D43/02T3E8, B65D41/34C|
|Jul 27, 2005||AS||Assignment|
Owner name: STACK TECK SYSTEMS LTD., CANADA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:RICK, DE CANDIDO;REEL/FRAME:016577/0896
Effective date: 20050221