US3434620A - Frangible plastic closure - Google Patents

Description

March 25, 1969 J. LAulzlo 2 FRANGIBLE PLASTI C CLOSURE Filed March 10. 1966 Sheet of 3 INVENTOR. JEREM/AH L Am? /2 /0 4 TTORNE).

March 25, 1969 J. LAURIZIO 3,434,620

FRANGIBLE PLASTIC CLOSURE Filed March 10, 1966 Sheet 2 4 I l/III I Ill/ll M /Zz@% 1N VENTOR. JEeEM/AH L A ue/z/a A TTORNEY J. LAURIZIO FRANGIBLE PLASTIC CLOSURE March 25, 1969 Sheet Filed March 10, 1966 INVENTOR. JFREM/A H A AUR/Z/O ATTORNEY United States Patent US. Cl. 220-47 Claims ABSTRACT OF THE DISCLOSURE A closure member found of synthetic plastic material for insertion in an opening in a container wall. The closure member defines a dispensing passage which is initially sealed off by a hand removable tear out diaphragm.

This invention relates to plastic closures for containers and is particularly concerned with such closures provided with a hand removable tear out diaphragm and method for forming the same.

It has become highly desirable in the plastic closure field to provide an integrally formed destructable diaphragm across the dispensing opening. Such a diaphragm construction not only insures against the possibility of leakage during shipment and handling of the container but in addition makes unauthorized tampering readily detectable. A secondary closure is at the same time provided to effect reclosing after the initial seal has been broken.

Various schemes have been presented whereby the integrally formed seal may be readily broken by the end user. Among these are puncturing with a sharp instrument, cutting out with a knife, pulling a tearing ear with a pair of pliers, all of which require the ready availability of some sort of tool or implement. Easily hand removability of such closure tear out diaphragms has been a problem the practical solution to which, has not until the instant disclosure been brought forth. One approach has been to reduce the thickness of the tearing zone in the diaphragm to an absolute minimum with the hope of breaking through that zone with force applied by ones fingers through a simple pull tab integrally formed with the diaphragm. However, even if the tearing zone could be accurately maintained at a few thousandths of an inch under production molding conditions, the force required to commence tearing of a commonly used plastic such as polyethylene is substantially more than can be applied by ones fingers gripping a simple pull tab.

Another approach to the problem of providing easy hand removability is to form the tab with suitable gripping means so that a sufiicient pulling force can be applied by ones fingers to commence tearing. This is the approach taken by the instant invention and the resulting successful construction embodies a finger loop integrally formed with the diaphragm. The new and novel method herein disclosed enables formation of a tear out diaphragm finger pull loop in a very simple and economical manner. Furthermore, through the invention method, the diaphragm can be molded within the dispensing passage with the finger loop extending angularly outwardly for easy accessibility while at the same time positioned to allow closing oil of the dispensing passage with a secondary reusable closure.

It is accordingly a principal object of the invention to provide new and improved plastic closures for containers.

Another object is to provide a new and improved method for making such closures.

Still another object is to provide the dispensing open- 3,434,620 Ce Patented Mar. 25, 1969 ing of plastic closures with an improved integrally formed tear out diaphragm.

A further object is to provide improved plastic closures having an integrally formed, easily hand removable tear our diaphragm.

A still further object is to provide an integrally formed plastic closure tear out diaphragm having improved finger gripping means for tearing.

A still further object is to provide an integrally formed plastic closure tear out diaphragm having a finger loop pull member for tearing.

A still further object is to provide a method of forming an integral tear out diaphragm and. finger loop pull member in recessed position within a dispensing opening.

A still further object is to provide a plastic closure member having a new and improved gasket seat.

Further and more detailed objects of the invention will in part be obvious and in part pointed out as the description of the invention taken in conjunction with the accompanying drawings proceeds.

In that drawings:

FIG. 1 is a top plan of a captive cap type closure embodying a tear out diaphragm formed in accordance With the invention;

FIG. 2 is a vertical section of the closure of FIG. 1.

FIG. 3 is a vertical section of the closure of FIG. 1 secured within a container wall;

FIG. 4 is a view similar to FIG. 3 with the closure in open position and the diaphragm removed;

FIG. 5 is a perspective view of the removed diaphragm and finger pull loop;

FIG. 6 is a vertical section of the mold in closed position for forming the closure of FIG. 1;

FIG. 7 is a view similar to FIG. 6 with the mold in open position;

FIG. 8 is a sectional view taken on lines 8--8 on FIG. -7 and looking in the direction of the arrows;

FIG. 9 is a top plan view of a closure member adapted to receive a plug and formed in accordance with the invention;

FIG. 10 is a part section part elevational view of the closure member of FIG. 9;

FIG. 11 is an enlarged fragmentary sectional view of a portion of the partly assembled closure;

FIG. 12 is a vertical section of. a complete closure assembly secured within a container wall; and

FIG. 13 is a vertical section of the mold in open position for forming the closure member of FIG. 10.

Considering first the captive cap type closure shown in FIGS. 1-4 the basic components thereof are seen to include a body portion 1, a cap 2 and a flexible hinge strap 3 connecting the cap and body. The entire closure is integrally molded as a single piece, in a manner hereinafter disclosed, from a suitable synthetic plastic material of which polyethylene is a nonlimiting example. The body 1 is a short tubular member sur ounded by an annular flange 4. Extending above the flange 4 is a cap receiving neck provided with an annular locking and gasketing shoulder 5. Extending below the flange 4 is a concave surface 6 which commences at the undersurface of flange 4 curving radially inwardly downwardly and then radially outwardly terminating in a zone 7 of maximum wall thickness. The exterior surface of the lower body portion terminates in a short downwardly and inwardly tapered pilot portion 8 to facilitate insertion in a container wall opening as hereinafter described. The inner surface 9 of the body 1 defines a passageway through which the container contents may be dispensed and which is initially closed off at an intermediate position by an integrally formed diaphragm 10. A circular tearing zone 11 of reduced thickness forms the juncture between the diaphragm and the inner body surface 9. Integrally attached to the diaphragm 10 adjacent its outer periphery is a finger loop pull member which extends upwardly and radially inwardly from the diaphragm in a short neck 12 and terminates in a circular loop 13. The size of the loop 13 is such that a persons finger can be easily inserted therethrough for pulling. In the embodiment of the invention here shown the finger loop pull member is positioned to extend outwardly in diametrical alignment with the hinge strap 3 as seen in FIG. 1. This relationship although advantageous in the mechanical handling of the cap, could be varied without departing from the scope of the invention. Of importance however is the fact that the pull member extend upwardly at an angle so as to be easily accessible for pulling. The approximate 45 degree angle shown, although by no means limiting, projects the loop 13 outwardly well beyond the upper end of body 1.

The cap 2 comprises a flat top panel 14 surrounded by a depending skirt 15. Extending radially inwardly from the inner surface 16 of the skirt is an annular rib 17 which has its outer surface tapered as indicated at 18 and joining the end surface 19 of the skirt. The flexible hinge strap 3 integrally joins the flange 4 of the body 1 with the top panel 14 of the cap 2. To facilitate opening of the cap a lift tab 20 extends outwardly from the skirt 15 as a continuation of the top panel 14 and diametrically opposed to the hinge strap 3.

In FIGS. 1 and 2 the closure is shown as it comes out of the mold with hinge strap 3 in a flat condition. The cap is then closed in a subsequent operation folding over the hinge strap 3 and, as shown in FIG. 3, the finger loop pull member is depressed by the cap top panel 14 so as to be enclosed within the upper portion of the body 1. Here it can be seen how the inclination of the pull member allows the same to be easily pushed down by the cap into its stored position. The tapered surface 18 on the cap skirt 15 aids in camming the skirt rib 17 over the locking shoulder 5 on the body 1 where the cap is thus held with the skirt end surface 19 in engagement with the upper surface of the body flange 4.

The closed unit can then be inserted in a container wall 21 provided with an opening surrounded by a short neck 22 extending downwardly and radially inwardly from the wall 21 and terminating in a free edge 23. In forcing the closure into the container wall opening the tapered body portion 8 aids in positioning the body 1 in the opening and squeezing the zone 7 of maximum wall thickness past the free edge 23 of the opening neck 22. Continued downwardly movement of the body 1 causes the undersurface of the flange 4 to seat against the upper surface of the container wall 21. Upon relieving the downward pressure the slight axial spring back of the body 1 due to the resilience in the flange 4 causes the neck free edge 23 to bite into the concave surface 6 effecting a permanent leakproof engagement. Any minor dimensional variation which may occur under production conditions in the inside diameter of the container wall opening is readily compensated for by the curved surface 6 which provides an infinite number of seating positions for the free edge 23. Variations due, for example, to wear in the container wall perforating and neck forming dies and different container wall thickness only cause the biting or digging in of the free edge 23 to occur at a slightly different position along the curved surface 6. The sealing remains completely effective however despite these variations. The container is now completely sealed against leakage either through or around the closure and any unauthorized tampering through destructive removal of the entire closure or the diaphragm 10 is readily detected.

Authorized access to the container contents is easily accomplished by flipping the cap 2 off of the body portion 1 by means of the lift tab 20. The pull member then springs back to its elevated position whereby ones finger can be inserted through the loop 13 and sutficient pulling force applied to commence tearing of the diaphragm 10 along the weakened tearing zone 11. FIG. 5 illustrates the diaphragm with its finger loop pull member after removal leaving only slightly roughened edge 11a on the inner surface 9 of the body 1 where the tearing occurred. After initial opening the cap 2 remains in raised position as shown in FIG. 4 due to the partial set taken by the hinge strap 3 when in closed position. Subsequent closing and sealing off of the dispensing opening is effected by again snapping the cap 2 in closed position.

A unique method for injection molding the above described captive cap type closure is illustrated in FIGS. 78 which show a mold comprising an upper member and a lower member 31. The upper member 30 is provided with a cavity portion 32 corresponding to the upper portion of the closure body 1, a portion 33 corresponding to the hinge strap 3 and a portion 34 corresponding to the cap 2. Numeral 35 indicates a sprue cavity portion for filling the mold. Completing the upper half of the mold is a moveable segment 36 connected to a vertically slideable pin 37. The segment 36 fills that part of the mold necessary for creating the cavity wall corresponding to the upper surface of the diaphragm 10 and the under surface of the pull loop 13 and connecting neck 12. The segment 36 is thus moveable axially away from the upper mold member 30 by means of the pin 37 with the cavity portions corresponding to the weakened tearing zone 11 and the remaining surfaces of the pull member being part of the upper member 30. The lower mold member 31 is provided with a cavity 40 for forming the lower tubular portion of the body 1 including the under surface of the diaphragm 10.

FIG. 6 illustrates the mold in closed position showing the mold parting line as lying in a plane corresponding to the lower surfaces of the flange 4, the hinge strap 3 and the cap top 14. The cavity is then filled and upon completion of the molding cycle the upper and lower members separate and the segment 36 moves away from the member 30. The molded piece is then removed preferably by suitable mechanical ejecting means from the segment 36. Removal of the sprue 35a may be carried out automatically in the mold or subsequently removed by hand, completing the formation of the finished piece. It should be noted that a number of arrangements could be employed in the relative movement of the above described mold members. For example, either of the members 30 and 31 could move axially while the other remains fixed and the segment 36 moves axially relative to the member 30 either after or simultaneously with the separation of members 30 and 31. Alternatively the segment could remain fixed and the members 30 and 31 separate relative thereto or of course all three members could also move simultaneously. What is important is the fact that the finger loop pull member is formed within the body of the closure in a very simple and economical manner employing only three mold members; upper member 30, lower member 31 and the segment 36. These members move only in an axial direction relative to each other in a unique manner thus forming a novel plastic closure which would on its face appear to require a much more complicated and expensive molding method.

FIGS. 9-12 illustrate another type of closure formed in accordance with the invention comprising a molded plastic plug receiving member generally indicated at and having a downwardly extending wall 51 internally threaded at 52 and terminating at its lower end in a tear out diaphragm 53. Connecting the diaphragm 53 and the lower end of neck 51 is a weakened tearing zone 54 of reduced thickness. Integrally formed with that diaphragm and closely adjacent the tearing zone 54 is a finger loop pull member having a short upwardly and radially inwardly extending neck 55 terminating at itsupper end in a circular pull loop 56. In the center of the diaphragm 53 a pocket 57 is formed having a side wall 58, a bottom wall 59 and a downwardly and inwardly inclined radial channel portion 60 extending between the tearing zone 54 and the wall 58. The upper end of the threaded wall 51 is provided with a peripheral securing lip having an inner wall 61, a top wall 62 and an outer wall 63 which extends downwardly and radially outwardly at a slight angle and terminates in a rounded free end 64. The interior surface 65 of the securing lip performs an effective gasketing function as hereinafter described. Also formed on the plug receiving member 50 at the upper end of the thread 52 is a gasket seat 66 which is radially spaced from the inner wall 61 by a circumferential upwardly opening groove 67.

The plug receiving member 50 thus described is permanently sealingly engaged about a container wall opening by means of a metal clamping ring 70 comprising an inner wall 71, a top wall 72 and an outer wall 73 terminating at its lower free end in an inwardly turned portion 74. The plastic member 50 and the clamping ring 70 are snapped together so that the ring 70 overlies the lip walls 61, 62 and 63 with the wall 71 having its lowermost free edge 71a extending below the gasket seat 66 into the groove 67. The inwardly turned end portion 74 of the ring 70 engages the end 64 of the outer lip wall 63 thus acting to retain the two members together as an assembly.

As seen in FIG. 12 the plug receiving member 50 is fitted with a closure plug 80 also formed of a synthetic plastic material and comprising a bottom wall 81 and a side wall 82 having an externally threaded portion 83, a seat 84 for retaining the gasket 85 and terminating at its upper end in a circumferentially enlarged head 86. Formed inwardly of the wall 82 is a pair of wrench engaging lugs 87. The bottom wall 81 of the plug 80 is formed with a downwardly extending internally threaded neck 88 which in turn receives a threaded plug 90 provided with a gasket 91 and generally similar to the plug 80. This type of combination plug lends a desirable degree of versatility to the closure in that the container contents may be dispensed through a pump or spigot adapted for use in either the large or the small threaded opening.

The assembly is completed with the provision of an overlying metal cap seal 95 having a top panel 96 and a depending skirt 97. To facilitate easy hand removal of the cap seal, gripping ear 98 extends away from the lower free edge of the skirt 97 and forms the commencement of a suitable tear strip (not shown) of the type defined by a pair of score lines extending across the skirt and top. The function of this lightweight seal is to prevent the entry and accumulation of dirt and water in and around the plug 80 and the gasket 81. This feature is desirable since the contents must be dispensed through the closure opening without contamination when such containers are stored under varied conditions over long periods of time.

In practice the closure manufacturer first assembles the closure receiving member 50 and the clamping ring 70. The combination plug 80 is then threaded into the member 50 with the gasket 85 being compressed against the gasket seat 66 and the inner ring wall 71. The provision of the groove 67 within which the lower end 71a of the inner ring wall 71 is housed, prevents the gasket 85 from being pinched in underneath the end 71a when the plug is tightened down. It has been found that when this end 71a is left exposed the gasket squeezes underneath the ring so that upon removal of the plug the gasket is caught by the end 71a and pulls right off the plug.

Continuing with the description of the assembled closure, the finger loop pull member is compressed into the diaphragm pocket 57 by the lower end of the plug wall 88 so that its neck 55 is housed within the channel portion 60 and the loop 56 is pressed down against the wall 59. The cap seal 95 is then placed over the plug and ring and the entire assembly supplied as a unit to the container filler. The filler then places the assembly over the opening of the container after the same has been filled through that opening. In FIG. 12 a container wall 100 is shown having an opening surrounded by an upwardly extending neck 101 which terminates at its upper end in an outward curl or bead 102. Hhere it can be seen that the slight outward inclination of the wall 63 acts as a lead for quick and accurate positioning of the assembly on the opening neck. The assembly is permanently sealingly engaged to the neck 101 by simultaneously crimping or otherwise forming the outer walls 63, 73 and 97 radially inwardly underneath the bead 102.

To subsequently gain access to the container contents the cap seal 95 is torn off and the plug removed whereupon the pull member springs back to its raised position as shown in FIG. 10. The loop 56 is then accessible for insertion by ones finger whereupon sufiicient pulling force can be easily applied to commence tearing of the diagram 53 along the tearing zone 54. Complete removal of the diaphragm 53 with its integrally formed pocket 57 and finger loop pull member unseals the container for initial dispensing after which tight reclosing may be effected by means of either of plugs 80 or 90.

The method of molding the plastic plug receiving member 50 is illustrated in FIG. 13 and is basically the same as that employed in forming the captive cap type closure shown in FIG. l4. This mold comprises an upper member 300 and a lower member 310. The upper member being pro-vided with a cavity portion 320 corresponding to the peripheral securing lip and gasket seat 66. Also provided in the upper member 300 is a thread forming portion 321. Moveably mounted in the upper member 300 is segment 360 connected to a slideable pin 370. The segment 360 fills that part of the mold necessary for creating the cavity wall corresponding to the upper surface of the diaphragm 53 and the under surface of the pull loop 56 and connecting neck 55. The segment 360 is thus moveable, in the same manner as described in connection with FIGS. 6 and 7, away from the upper member 300 with the cavity portions corresponding to the weakened tearing zone 54 and the remaining surfaces of the pull member being part of the upper member 300. The lower mold member 310 is provided with a cavity 400 for forming the wall 51 and the diaphragm 53 of the member. Numeral 410 indicates a sprue cavity portion for filling the mold. The mechanical forces applied to th pull member during the ejecting operation cause the difference in inc1ination of the loop 56 as seen comparing FIGS. 10 and 13.

The foregoing disclosure as embodied in the two different types of closures now makes it possible to provide an integrally molded plastic closure member having a tamperproof tear out diaphragm which can be easily removed with the unaidet hand. In terms of convenience this feature is of course most meritorious however, just as important is that fact that the use of implements for puncturing and cutting frequently causes contamination of the container contents. The invention eliminates this possibility. Furthermore, through the method therein presented the finger loop pull member can be formed in a simple and economical manner within a closure 'wall where it can be depressed to accommodate an overlying secondary closure for reuse and also raised outwardly for easy access.

It is, of course to be understood that various changes may be made in the construction and method described and shown and that various other embodiments of the invention can be made without departing from the spirit and scope thereof. It is accordingly intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention what I claim is new and desire to secure by Letters Patent is:

1. In closure construction, an annular body member molded of synthetic plastic material, said body member defining an axial dispensing passage, an integrally formed diaphragm closing of said passage, a weakened tearing zone connecting said diaphragm and said body member, a pull member integrally connected to said diaphragm adjacent said tearing zone, said pull member formed with an annular finger loop adapted to receive a single finger to enable hand removability of said diaphragm by tearing.

2. In closure construction as in claim 1, said diaphragm formed within said dispensing passage with said tearing zone below the upper end of said body member.

3. In closure construction as in claim 1, said pull member comprising an upwardly and radially inwardly extending neck connected at its lower end to a peripheral portion of said diaphragm and terminating in said finger loop.

4. In closure construction as in claim 1, including closure engaging means formed on said body member about said diaphragm.

5. In closure construction as in claim 4, said pull member extending above said closure engaging means.

6. In closure construction as in claim 4, including a closure member secured to said closure engaging means and confining said pull member between said closure member and said dispensing passage.

7. In closure construction as in claim 6, wherein said pull member is axially depressed by said closure.

8. In closure construction as in claim 1, including an annular container neck engaging surface formed on the exterior of said body member having a concavely curved cross sectional configuration.

9. In closure construction as in claim 8, including a container wall opening surrounded by a downwardly and radially inwardly extending conical neck terminating in a free edge, said free edge biting into said concavely curved surface thereby eflFecting a permanent leakproof engagement between said container wall and said body member.

10. In closure construction as in claim 1, wherein said weakened tearing zone has a reduced cross-sectional thickness and a substantially V-shaped cross-sectional configuration whereby the tearing force is concentrated at the reduced section at the apex of the V-shape.

References Cited UNITED STATES PATENTS 3,127,064 3/1961 Fairchild 220---38.5 3,135,441 6/1964 Wise et al 222-541 3,239,112 3/1966 Porcelli 222-541 GEORGE T. HALL, Primary Examiner.

US. Cl. X.R.

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