US3463341A

US3463341A - Tamper-indicating closure

Info

Publication number: US3463341A
Application number: US691496A
Authority: US
Inventors: Mack R Fields
Original assignee: Roehr Metals and Plastics Co
Current assignee: Roehr Metals and Plastics Co
Priority date: 1967-12-18
Filing date: 1967-12-18
Publication date: 1969-08-26
Anticipated expiration: 1986-08-26
Also published as: GB1181048A; FR1601471A; DE1814680A1; BE724941A

Description

Aug. 26, 969 M. R. FIELDS 3,453,341

TAMPER- INDICATING CLOSURE Filed Dec. 18, 1967 FIG.

INVENTOR MA0 R. FIELDS United States Patent Ofiice 3,453,341 Patented Aug. 26, 1969 3,463,341 TAMPER-INDICATING CLOSURE Mack R. Fields, Lighthouse Point, Fla., assignor to Roehr Metals & Plastics Company, a limited partnership of Connecticut Filed Dec. 18, 1967, Ser. No. 691,496 Int. Cl. B6511 17/16 US. Cl. 215-42 6 Claims ABSTRACT OF THE DISCLOSURE A molded plastic cap has a tamper-indicating skirt joined to the end of the cap sidewall by spaced frangible bridges of the plastic. The cap is mounted on a plastic container that has radial tongues that project through the gaps between the bridges. Rotation of the cap incident its removal from the container causes the tongues to rupture the bridges and separate the skirt from the main body of the cap.

This invention relates to improvements in closures of the so-called tamper-indicating type.

It is an object of this invention to provide a tamperindicating closure having an annular tamper-indicating skirt that is joined to the annular sidewall of the closure by a series of circumferentially spaced bridges of material that leave radially open arcuate gaps between the sidewall and the tamper-indicating skirt except where the two are joined by the bridges, and wherein the container is integrally formed with radially outward projections or tongues that extend through the gaps and prevent initial removal of the closure without rupture of at least some of the bridges. Upon rotation of the closure and container relative to one another incident to opening of the container, the tongues shear the bridges and cause the tamper-indicating skirt to be separated from the remainder of the closure. The remainder portion of the closure may then be withdrawn from the container. Fractured bridges or an absence of the skirt indicates that the closure has been removed or that there has been tampering with the same.

In one form of the invention the container and closure are devoid of screw threads and so may be assembled by merely axially shifting the closure onto the container without rotation of either, the two being held assembled by the presence of the tongues in the gaps. The tongues are sufiiciently flexible to allow the closure skirt to pass thereover causing the tongues to be flexed inwardly; however, as the closure approaches or reaches its final closed position on the container, the tongues will flex back substantially to their initial position to engage in the gaps. In another form of the invention, the closure and a container neck are threaded and the container has outward projections or tongues below the thread. The bridges on the cap are yieldable so as to stretch outwardly within elastic limits to allow the projections to underride the bridges as the closure is threaded onto the container. As the projections move rotationally past the bridges and in axial alignment with the gaps the bridges will flex back to their normal positions, leaving the projections extending through the gaps.

In the formation of a package having an unthreaded container and closure, each of which is of plastic, it has been a practice to hold the two assembled by heat-fusing them at adjacent telescoping surfaces. A further object of this invention is to provide a tamper-indicating closure and container of the type stated which eliminates the need for heat-fusing or otherwise providing for a separate structure and assembly operation for securing the closure onto the container.

The attainment of the above and further objects of this invention will be apparent from the following description taken in conjunction with the accompanying drawing forming a part thereof.

In the drawing:

FIG. 1 is a sectional view of the closure taken along the longitudinal axis thereof and showing the closure mounted on a container;

FIG. 2 is a fragmentary sectional view, on an en larged scale, taken along line 2-2 of FIG. 1;

FIG. 3 is a fragmentary sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 1;

FIG. 5 is a fragmentary sectional view taken along the vertical axis of a modified form of closure embodying the present invention;

FIG. 6 is a sectional view, on a reduced scale, taken along line 6-6 of FIG. 5

FIG. 7 is an enlargement of a portion of FIG. 6 and FIG. 8 is an enlarged elevational view of a portion of the closure of FIGS. 5-7.

Referring now in more detail to FIGS. 14 of the drawing, 1 designates a closure having an end wall 2 and a depending cylindrical sidewall 3. The outer surface of the sidewall 3 is formed with outwardly projecting, circumferentially spaced finger-gripping ribs 5 which extend for the length of the sidewall 3 and which facilitate manipulation of the closure 1. At its lower portion the sidewall 3 tapers down to a narrow lower rim or periphery 6, and adjacent to the lower periphery 6 is a cylindrical tamper-indicating skirt 7 which may be coaxial with the sidewall 3. The sidewall 3 and skirt 7 are joined by a series of circumferentially spaced frangible bridges 9 of closure material which span the space between the lower periphery 6 and the upper rim or periphery 10 of the skirt 7, leaving radially open arcuate gaps 11 between the sidewall 3 and skirt 7 except where the two are joined by the bridges 9. Each bridge 9 may have a radial thickness that is the same as that of the sidewall 3 at its lower periphery 6 but much less than that of the skirt 7 at its upper periphery 10. Furthermore, each bridge 9 may be tapered so as to have its thinnest section at the periphery 6. In the form of the invention herein shown there are eight equally spaced bridges, being each located adjacent to one of the ribs 5, but it will be understood that the invention is not limited to the precise number of bridges 9 herein shown.

The closure 1 is molded as a one-piece member. This may be done with conventional apparatus or preferably with apparatus of the general type shown in United States Patents 3,247,548 and 3,329,295. The plastic used is preferably a polyolefin, such as polyethylene or polypropylene, but other plastics, such as high-impact strength polystyrene, may be used.

One form of container 13 with which the closure cap 1 may be used has an annular end portion 14 that defines an opening 15 into the container. The end wall 2 is dis posed across the opening and may seat against the end portion 14. The end portion 14 preferably has an outer cylindrical wall 17 that telescopes within the closure sidewall 3 and the latter may have axially spaced circular sealing ribs 18 that engage the wall 17. Remote from the container opening 15 the container 13 may have an inwardly extending shoulder 19, and at the radially inner edge thereof a tubular portion 21 of smaller diameter than that of the end portion 14. A container 13 of the foregoing shape with the widened end portion 14 may be suitable where product to be housed therein is a syringe, although it should be understood that containers having other shapes may be used with the closure 1.

Integrally formed on the end portion 14 at or near the shoulder 19 are circumferentially spaced tongues 23 which project radially outwardly of the end portion 14 and through the gaps 11 to lie radially outwardly beyond the bridges 9. As best seen in FIG. 2, the tongue 23 may be rectangular in cross section with the longer dimension being in the circumferential or horizontal direction and the shorter dimension being in the axial or vertical direction. Four equally spaced tongues 23 are illustrated but a greater or lesser number of them might be used. These tongues 23 prevent separation of the closure 1 and container end portion 14 without fracture of the bridges 9. Thus, a fracture of all of the bridges will cause the skirt 7 to separate from the main body of the closure 1 and will indicate tampering with the closure. Tampering may also be indicated by a fracture of one or more of the bridges 9.

When it is desired to remove the closure 1 from the container 13, the two are twisted relative to one another causing the edges of the tongues 23 to shear the bridges 9 and separate the skirt 7 from the main body of the closure, which may then be withdrawn from the container end 14. The closure minus the skirt 7 may be reused as an ordinary cap. Because the tongues 23 are relatively long in the circumferential direction, they present relatively strong and rigid members against the bridges l) to facilitate rupturing them easily.

With four equally spaced tongues 23 and eight equally spaced bridges 9, all of the bridges 9 will be broken after a one-quarter turn of the closure. One group of four bridges will first be broken, followed by the remaining four. However, a different sequence of severance may be created by the use of unequally spaced bridges or unequally spaced tongues, or a combination of both, depending upon the sequence of bridge breakage desired.

The closure 1 may be mounted onto the container 13 by axially telescoping the sidewall 3 over the end portion 14 without the necessity of having to rotate either. As the conical surface 25 on the skirt 7 meets interference with the tongues 23, the skirt 7 may yield somewhat but the tongues 23 will bend within their elastic limits inwardly (downwardly as viewed from FIG. 1) to allow the skirt 7 to pass thereby. As the closure axially approaches its final closed position, the tongues 23 will then spring back to their original positions and project loosely through the gaps 11. Because each tongue 23 is relatively thin in its axial dimension, it may be easily flexed by the skirt 7. Nevertheless, the relatively large circumferential dimension of each tongue 23 results in it being fairly rigid when it imposes force on a bridge 9.

So that the tongues 23 will have the desired resiliency within elastic limits for the foregoing purposes, the container 13 should be of a relatively resilient material. Plastics of the polyolefin type, such as polypropylene or polyethylene, are suitable for molding of the container 13. To enhance their flexibility, the tongues 23 may be thinned out where they are joined to the end portion 14.

Desirably, the closure and container will be oriented immediately prior to assembly so that upon axial telescoping of the two the tongues 23 will be circumferentially offset from the bridges 9; otherwise the tongues 23 will end up lodged behind the bridges 9 and will be prevented from snapping into the gaps 11. However, where there is no predetermined orientation, the closure may have unequally spaced bridges 9 and/or the container may have unequally spaced tongues 23 designed such that regardless of the orientation of the closure and container only one tongue would be lodged behind a bridge. Such a condition would not impede the fracture of the bridges upon initial removal of the closure although more rotation of the closure will be required than would be the case if all of the tongues were in the gaps 11.

If a severance of all of the bridges 9 and a subsequent complete separation of the skirt is not desired, it is possible to mold the closure with one of the bridges located so that it is not severed by a tongue. Such a bridge might be one that is radially outwardly of all of the others so that it is not engaged and cut by any one of the tongues. An arrangement of this type would avoid the necessity of discarding the skirt as a separate piece but would still indicate tampering by the fracture of the other bridges.

FIGS. 58 show another form of the invention in which like reference characters followed by a denote parts corresponding to the parts of the container and closure of FIGS. l-4. As best seen in FIG. 5, the closure 1a has a cylindrical sidewall 3a with an internal helical thread 25 and a compressible sealing disc 16. A bottle 1311 or like container has an annular end portion or neck 14a with a matching external helical thread 26 for threadedly receiving the closure 1a. The upper periphery 10a of the tamper-indicating skirt 7a is attached to the lower periphery 6a of the closure sidewall 3a by circumferentially spaced bridges 9a of plastic closure material. As seen in FIG. 5, the bridges 9a may be molded so that they bow radially inwardly.

Integrally formed on the container 13a below the thread 26 is an annular radially outwardly extending bead 28, which may be the transfer ring of the container. The bead 28 has diametrally opposed tongues or

projections

30, 30 which extend radially beyond the normal diameter of the bead 28. These projections are relatively rigid in the circumferential direction and are generally hook-shaped, opening in a clockwise direction as viewed from FIG. 6. If the container 13a is a blow-molded plastic bottle, the peaks of the projections may lie along the parting line of the mold parts.

The diameter across the peaks of the

projections

30, 30 is, of course, greater than the outer diameter of the skirt 7a so that when the closure 1a is screw-threaded onto the container neck 14a, to close the opening 15a, the

projections

30, 30 will extend through the gaps 11a. In the clockwise threading of the closure onto the neck 14a, the lower or free end of the skirt 7a interferes with the

projections

30, 30. Upon further threading together of the closure and neck, the skirt 7a resiliently deforms into an oval shape to clear the peaks or apexes of the

projections

30, 30 and thereafter returns substantially to its originally molded shape. As the projections 30, 30' pass over the bridges 9a, the latter will also yield by bowing radially outwardly but will return substantially to their normal molded positions after the projections 30', 30 have passed thereby and become positioned in the gaps 11a. By proper choice of plastic for the closure 1a, the resilient yielding of the skirt 7a and bridges 9a without breaking of any of them is possible. Polyolefin plastics, such as polypropylene and polyethylene, are suitable for this purpose.

In initially unscrewing the closure from the container neck, the hook-

like projections

30, 30 will engage the bridges 9a at their slanted sides 31, shearing the bridges 9a generally at the surface 6a. This causes the skirt 7a to be separated from the remainder of the closure and indicate tampering or previous removal of the closure from the container. The closure may thereafter be used with the container as an ordinary screw cap.

In one form of the structure of FIGS. 5-8 the closure 1a may be of the twenty-eight millimeter size, in which case the diameter between peaks of the

projections

30, 30 may be about 1.250 inches. The normal outer diameter of the bead 28 remote from said projections may be about 1.050 inches and the minimum in the diameter of the skirt 7a may be about 1.140 inches. With a standard six-pitch thread and a closure having eight bridges, the maximum rotation needed for separation of the skirt 7a is one-hundred-eighty degrees with a 0.83 axial movement of the closure relative to the container neck. Normally, the axial width of each gap 11a should be .083

inch plus twice the thickness of the

projections

30, 30 or about .183 inch. However, by the time the last two unbroken bridges contact the projections during the removal operation, the skirt 7a will yield downwardly so that gaps 11a of about .125 inch should ordinarily be sufiicient.

The container 13a may be produced by a two-stage molding process in which the neck portion with the thread 26 and

projections

30, 30 are injection molded with a tubular body portion attached thereto. Then while the molded piece is still hot the tubular body portion is transferred to a second mold and blow molded. Such a process provides accurate dimensional tolerances for the neck of the bottle, especially as concerns the

projections

30, 30.

The precise construction herein shown is illustrative of the principles of the invention. What is considered new and sought to be secured by Letters Patent is:

1. In combination with a container having an opening, a tamper-indicating closure for said opening, said closure comprising a. wall, a skirt adjacent to one end of the wall and having a peripheral portion spaced from an adjacent peripheral portion of said wall, said peripheral portions being joined by means forming a zone of weakness that includes a bridge of material that spans said space but is of such peripheral size as to leave part of said space unoccupied, said wall and skirt being telescoped with a part of said container, and means projecting from said container part and through said space an amount suflicient to prevent separation of the closure and container Without rupture of the closure at said Zone of weakness, said projecting means being sufliciently flexible within the elastic limits thereof to be flexed by said skirt to permit said skirt to pass thereacross during assembly of the closure and container by axial shifting of one relative to the other and then to reflex and engage in said space.

2. A combination according to claim 1 in which said closure and container part are rotatable relative to one another to enable said projecting means to shear said bridge of material prior to separation of the closure and container part.

3. In combination with a container structure having an annular portion, a closure structure having an annular wall disposed about said annular portion, the radially outwardly presented surface of said annular portion and the radially inwardly presented surface of said annular wall having such contours as to permit relative rotation of the two structures and assembly of the two structures, an annular skirt adjacent to one end of said annular wall, said skirt being joined to said wall by circumferentially spaced bridge elements of material of said closure structure, and circumferentially spaced tongue elements integrally formed on said container structure and projecting radially outwardly therefrom and into the gaps that run circumferentially between two bridge elements and axially between said skirt and annular wall an amount suflicient to prevent axial separation of the two structures without rupture of said bridge elements, the elements on at least one of said structures being sufliciently flexible to flex within their elastic limits to permit said skirt to pass across said tongue elements and then to reflex and position said tongue elements in said gaps upon assembly of said two structures, said tongue elements having circumferential dimensions sufficiently small to provide circumferential spacing between them and the adjacent bridge elements so that the closure and container are capable of an initial relative rotation to bring a tongue element and a bridge element into engagement and a further relative rotation to rupture said bridge elements by said tongue elements, the circumferential spacing of the tongue elements and bridge elements and the number of each being such that less than all of the bridge elements will be ruptured at one time.

4. In combination with a container having an opening, a tamper-indicating closure for said opening, said closure having a wall, said wall and container being in threaded engagement, a skirt adjacent to one end of the wall and having a peripheral portion axially spaced from an adjacent peripheral portion of said wall, said peripheral portions being joined by circumferentially spaced bridges of material that span said space, and means comprising a tongue radially projecting from said container and through said space an amount sufiicient to prevent separation of the closure and container by unthreading without rupture of said bridges, said tongue being circumferentially spaced from an adjacent bridge to enable an initial relative unscrewing movement of the closure and container to bring the tongue and said adjacent bridge into engagement and a further relative unscrewing to break said bridges, said means comprising said tongue being disposed relative to said bridges so as to rupture less than all of said bridges at one time.

5. A combination according to claim 4 in which said tongue is a hook-shaped element with the hoop opening toward said adjacent bridge.

6. A combination according to claim 3 in which said structures are threaded together, said tongue elements each have a bridge element-engaging edge, and said adjacent bridge elements are respectively first engaged by the respective bridge element-engaging edges of the tongue elements upon relative rotation of the two structures tending to unthread them.

References Cited UNITED STATES PATENTS 3,329,295 7/1967 Fields 215-42 3,407,976 10/ 1968 Homma 215-42 FOREIGN PATENTS 654,848 6/ 1963 Italy.

GEORGE T. HALL, Primary Examiner U.S. Cl. X.R. 220-27; 222541 23 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3463341 Dated August 26 1969 Inventor(s) Mack R. Fields It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6 line 36 "hoop" should read -hook.

SIGNED AND SEALED MAR 3 1970 SEA Am M- M. J a" 18s z. a Attoating Offioer admission" or Pawn