Tear-type plastic closure with plastic pull ring

BACKGROUND OF THE INVENTION

This invention relates to container closures of the type having a molded plastic flap integrally connected to a surrounding mounting band by a frangible or tearable web so that the container may be opened by pulling the flap away from the band, which is secured to the container, and then reclosed by pressing the flap back into substantially its original position within the band. Examples of prior closures of this general “tear” type are found in Patents Nos. 3,083,858 and 3,370,757.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a novel tear-type plastic closure in which the flap recloses in the top wall of the container itself rather than in the mounting band or ring and thus is not dependent upon the resealing and retention characteristics of the two parts originally joined together by the tearable web. A related object is to provide a plastic and sheet metal closure adapted to be mounted on a sheet metal container with conventional hemming techniques and including a teartype closure flap that is securely backed by and recloses around a metal lip defining the opening in the container for access to the contents thereof. Still another object is to provide a convenient and easily accessible pull ring for use in tearing the web during the initial and subsequent opening operations, and to store the ring in a novel manner on the closure in an out-of-the-way position permitting compact stacking of such containers.

Other objects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a fragmentary perspective view showing a closure embodying the novel features of the invention mounted on a container.

FIG. 2 is an enlarged fragmentary cross-sectional view taken substantially along the line 2—2 of FIG. 1, in the direction of the arrows.

FIG. 3 is an enlarged fragmentary cross-sectional view taken substantially along the line 3—3 of FIG. 1.

FIG. 4 is a fragmentary cross-sectional view through the plastic part of the closure in the position in which it is molded.

FIG. 5 is a plan view of the plastic part of the closure of FIG. 1.

FIG. 6 is an enlarged fragmentary cross-section taken along the line 6—6 of FIG. 5 and illustrating a hinge for retaining the flap on the closure.

FIG. 7 is a view similar to part of FIG. 2 showing an alternate form of the invention.

FIG. 8 is an enlarged fragmentary view similar to part of FIG. 2 illustrating another alternate form with the pull ring in the free position.

DETAILED DESCRIPTION

As shown in the drawings for purposes of illustration, the invention is embodied in a closure, indicated generally at 10, for a cylindrical sheet metal container 11, suitable for use as a coffee can or as a container for a variety of other products, and having an open upper end to which the closure is secured in a conventional manner. The central portion of the closure comprises a flap 12 molded of suitable plastic such as low density polyethylene, herein of circular shape and encircled by a continuous plastic band 13 forming a mounting ring initially joined around its inner periphery to the outer periphery of the flap by a thin and narrow web 14 (see FIG. 3) of plastic forming a tamper-proof tearable joint that holds the flap in the closed position and normally seals the container until it is to be opened for use.

To open the container 11, the flap 12 is lifted away from the mounting ring 13 to tear the web 14 and remove the flap from its normal position overlying the opening into the container. In some instances, the tearable web extends completely around the flap for complete removal of the latter during the opening operation, and in other instances, as here, a section 13^a of (FIGS. 5 and 6) the web is thickened to form a flexible hinge on one side of the flap for holding the flap captive on the container and facilitating reclosing of the container.

In the aforementioned patents, tear-type closures of now-conventional construction are shown in which the cap or flap is torn away from the plastic top of the closure and then reseated on or in the plastic to reclose the container. In accordance with a primary aspect of the present invention, the closure has a top wall member 15 mountable on the container 11 and itself defining the container ¹ opening, and the plastic mounting ring 13 is anchored on this wall member around the flap 12 with a depending rib 17 on the flap telescoped with the wall member to close, and subsequently reclose, the opening independently of its joinder to the plastic mounting ring. Thus, the combina> tion of the top wall member, the mounting ring and the removable flap forms a more rigid initial closure in which both the flap and the ring are backed by the top wall member, and reclosure of the flap is accomplished by pressing the rib back into the opening in the top wall member without reliance on the return of the plastic flap into sealing relation with the ring after tearing of the web.

In the first embodiment shown in FIGS. 1-6, the top wall member 15 is a sheet metal ring having an outer upright wall 18 sized to fit into the open end qf the container and terminating in an inner upright wall or lip 19 defining the opening of the container, the ring having an annular, upwardly opening groove 20 just inside the outer wall and separated from the lip by an annular shoulder 21 encircling the opening. The lower edge portion of the lip is curled under and upwardly at 22 to dispose the free inner edge 23 in an out-of-the-way position.

To secure the plastic part 12, 13 of the closure 10 to

3,494,500 the top wall 15,. the mounting ring 13 is fitted into the groove 20 with its lower end pressed into a layer 24 of sealing compound in the groove, and is anchored in place by at least one indentation 25 in the outer wall 18, preferably a bead rolled completely around the wall to clamp plastic between the walls of the groove. A second bead 27 is rolled into the outer wall around the upper edge of the ring to complete the anchoring and sealing of the ring 13 on the closure. It will be seen in the drawings that the flap 12 is simply a circular plate of plastic that fits closely within the mounting ring and has a peripheral bevel 28 which reduces the thickness of plastic at the tear line to a thin membrane capable of being torn with relative ease as the flap is pulled away from the remainder of the closure. On one side of the flap, herein opposite the hinge 13^s, a weakened section or a gap 29 may be formed in the web for easy starting.

The peripheral portion of the flap 12 overhangs and rests on the shoulder 21 and thus is backed securely in the closed position, and the rib 17 depends from the underside of the flap to telescope in snugly interfitting relation into the lip 19 completely around the latter, herein being reinforced by triangular braces 30 molded integrally with the flap and equally spaced around the rib. To provide snap reclosure of the flap, one or more nibs 31 are pro- 25 vided around the outer side of the rib to project outwardly beneath the curl 22. Herein, four such nibs are equally spaced around the rib. It should be noted, however, that they are not essential for tight reclosure in view of the snug fit of the rib within the lip, and it often is desirable 30 to avoid positioning a nib adjacent the starting point of the tear for easier starting.

To facilitate the opening of the container 11, both initially and after the container has been reclosed a null hfnZe^d13Mj^atheⁿca^One f^{ide of}f^the_fl^flap opposite the 35 adjacent ThepoTnt of connectionTZthe pulfri ninge 13 m the case of a captive flap and herein on the . .. left side as viewed in the drawings. In accordance with an important aspect of the invention, this pull is in the form of a ring 31 molded integrally with the flan 12 initiaiiv in , · · ,° a ., ξ . ’ ““I' ^lllar ^uc ummea ror easier initial opening of the

Slav's SUWtS R⁴⁰ 5» ^IfA^sired· · w* »»·» M ».y »· «Λ ·.’«» use in opening the container, as shown in FIG. 4, and a retaining abutment 32 is positioned on top of the flap to latch the pull ring releasably in a substantially flat posi- ......

tion against the top. In this way, an easily grippable pull 45 container is provided as an integral part of the closure capable of being molded with conventional techniques, and normally is held neatly in an out-of-the-way position avoiding interference with stacking of containers.

. In (hi, L p„„ _{ring 3I is si}„_pIy , _cil„_{llar 5}„ Se'd ring of plastic of substantial thickness having a center ' ' hole sized to receive the index finger with a free fit, and is joined to the flap close to the tear line by a flexible strap of plastic initially disposed in the same inclined plane _{O1UC ailu seHlpn ησηιΤΊσ} .ch_PPf as the ring. As molded, these parts are inclined at an angle 55 around the periphery oi the plastic parts of approximately forty-five degrees with the plane of f--------- --.. ^y . P^lastIC P^arts>

the flap. The retaining abutment is the side of a lug 32 upstanding from the top of the flap and inclined away from the point of connection of the strap to the flap, being _{ulv eluau}spaced from this point a distance selected so that the ring 60 Herein the overlay may be hooked over the lug and stressed slightly to lock -- - ^y the ring releasably around the lug in the manner shown in FIGS. 1, 2 and 5. It will be seen that the lug and the inner wall of the ring constitute opposed, interfitting abutments for releasably holding the ring in place.

Thus, when the container is to be opened, the pull ring 51 is released by pulling it away from the retaining lug 52, and then is used to obtain a firm grip on the flap for he initial pull required to tear the web and separate the lap from the mounting ring all the way to the hinge 13^a. The gap 29 in the web reduces the pull required to start he tear, and the tapering of the strap 33 to a very narrow width at the point of connection concentrates the pull brce at the gap. Of course, the snug engagement of the despite this gap. After the desired quantity of product has been removed from the container 11, the flap 12 is simply is pressed back into place to force the rib 17 back into the opening. The lower edge of the rib is beveled at 34 to guide the rib back into the opening while camming the ribs inwardly to pass the lip and then snap outwardly as the nibs pass below the curl 22. Then the pull ring may be stretched and hooked back over the lug 32 into the storage position.

It will be evident that this closure provides a replacement for conventional coffee can closures of the popular type having sheet metal tops removable with a can opener, such cans presently being sold with snap-on plastic covers for reclosing the can after they have been opened. This eliminates the need for a can opener by providing a sealed, tamper-proof tear-type closure that is reclosable within the top wall of the container rather than in the mounting alone.

In FIG. 7, an alternative form is shown in which corresponding parts are indicated with corresponding primed reference numbers, this form being generally the same as the first form except that the flap 12' is formed with a rib 17' that telescopes over an upstanding lip 19' defining the container opening. In this instance, the plastic mounting ring 13' is fitted into a groove 20' and anchored therein by an annular flange 27' on the top wall member 15' folded or bent over into the top of the ring, and the rib depends from the edge of the flap outside the lip, which is inclined upwardly and outwardly and comprises a double layer of sheet metal terminating in a downwardwardly facing free edge 23'.

The tear line is defined by a web of plastic integrally joining the lower edge of the rib 17' to the adjacent edge of the mounting ring 13', and may include a gap at 29' . . ... - ,.----- ring strap 33' to the flap. To provide snap reclosure, nibs 31' are formed around the inner side of the rib to abut against the inclined outer side of the lip, and the nib adjacent the pull strap may be omitted for easier initial opening of the wall of the container to close, or substantially close, the space 37 between the outer sidewall of the groove 20' and the container in order to avoid trapping of product in this area during pouring of the contents from the

In another of its aspects, the invention contemplates a novel plastic closure of the foregoing character which provides a virtually air-tight seal despite the permeability of the plastic which permits the passage of gas through ------ — —is filled and closed. For this purpose, an overlap 38 (FIG. 8) of tearable impervious sheet material such as aluminum foil is applied to one side of the plastic parts of the closure, herein the top side^ and sealed against the sheet metal top wall 7 ' 7“- , -. _r----, to cover all of the exposed plastic except the pull ring strap 33 and the retaining, lug 32 which project through small apertures m the foil. This forms a completely hermetic seal except for the small apertures, the effect of which is negligible. HTa-r..-. rt. j_{s s}f,_own j_{n con}j_uncti_{on w}jtjj the preferred form of the closure of FIGS. 1—6, and corresponding reference numbers are applied to the closure.

As shown in FIG. 8, the foil overlay 38 is a sheet of the same diameter as the outside diameter of the mount65 ing ring 13, and may be bonded to the plastic parts of the closure as an incident to the injection molding of the latter. For this purpose, an imperforate sheet of foil is positioned in the dies (not shown) on one side of the die cavity across the portions of the cavity in which the 70 pull and the retaining lug are to be formed. As molten plastic is injected into the cavity from below, the injection pressure will cause the plastic to rupture the foil in the unbacked areas and flow into the pull and lug portions, thereby forming the apertures in the manner illusih η _π,ιλ tho ι: <η . , . 7, .----- “^u“°> “ivicuy luiiiuug uie apertures m tne manner illusib 17 with the lip 19 maintains the container sealed 75 trated in FIG. 8. After the plastic has cooled and set,

3,494,500 a lug upstanding from said flap and positioned to fit within said ring and hold the latter re5 the foil is bonded thereto and is generally coextensive with the top surface of the plastic parts. Rolling of the bead 27 over the outer edge portion of the mounting ring and the foil thereon completes the seal around the periphery of the plastic.

As in the other form, the flap 12 is joined to the mounting ring 13 by a tearable web 14 that may have a gap at 29, and also by the foil overlay 38 which covers all of the joint. As the flap is opened, both the foil and the web are torn along the tear line. If the foil is not securely anchored by the bead 27, however, it is possible that it may simply separate from the mounting ring 13 without tearing. It should be noted that such an overlay also provides an exposed outer surface that is better adapted for decorating than is plastic, and will take a printed surface coating better than the plastic.

Any of the illustrative closures may be mounted on containers in a conventional mass production operation simply by fitting the closure within the open end of a container after the ring 13 has been anchored in the top wall, and interfolding the upright cylindrical walls to form a seam 39 extending around the upper end of the container. While this is a preferred arrangement for sheet metal containers, it will be evident that other types of mounting may be used.

From the foregoing, it will be seen that the present invention provides a novel molded plastic closure formed by the mounting ring and the closure flap, joined together by the tearable web, and adapted for incorporation in a combined metal and plastic closure including the top ³⁰wall member mountable on the container in a conventional manner. When so combined, the flap overlies and snugly interfits with the metal lip defining the opening for access to the container, and is backed securely by the eluding thereon leasably and substantially flat against the flap.

5. A container closure as defined in claim 1 in which said web has a weakened section at said one side facilitating initial tearing off of said flap.

6. A container cover as defined in claim 5 in which said weakened section comprises an interruption in said web leaving a gap between said flap and said plastic ring, and further including an impervious overlay of tearable sheet material covering said flap and at least part of said plastic ring, said overlay sealing said gap and the plastic parts of said closure.

7. A container closure having, in combination, a top wall member adapted to be secured to a container and having an inner lip defining an opening of preselected shape for access to the container through said wall member, and a closure member comprising a peripheral band extending around said opening and secured to said wall member radially outwardly from said lip, a closure flap overlying said opening and surrounded by said band, a frangible web between the periphery of said flap and the inner periphery of said band joining the two together thereby to close said opening, an annular rib depending from said flap and telescoping with said lip in snug interfitting relation therewith, and means connected to said flap adjacent one side thereof for pulling the flap away from said wall member and said band to tear said web while pulling said rib away from said lip, said rib being movable back into snugly telescoped relation with said lip for reclosure of said opening after tearing of said web.

8. A container closure as defined in claim 7 in which said rib is formed with at least one retaining nib interfitting with said lip with a snap-locking fit and cooperat- access IO IIlv LUilLdlllUl, dllix 1O uaviwu xj ''J X1.1.L1 r *. , top member while being reclosable within the sheet metal ³⁵ ing in holding said flap m place after reclosure of said member rather than in the plastic mounting ring as in prior tear-type closures. In addition, the novel pull ring is formed in a manner that permits the use of conventional molding techniques, provides an easily accessible ------ -null for optimum force application, and is latched releas- ⁴⁰ pull integrally joined to said flap adjacent said one side ably in an out-of-the-way position when not in use. —^J f™» awav from the nlane

Finally, the impervious overlay may be added to the closure for a virtually hermetic seal despite the permeability of the plastic and without unduly complicating the molding operation or the opening of the container.