GB2138411A - Tamperproof container and closure assembly - Google Patents

Abstract

A tamperproof container and closure assembly comprises a container (2) having a relatively wide mouth (4) around which is formed a discontinuous screw- thread (6) and on which is provided a substantially radially-outwardly projecting abutment surface (14). A cap (16) for the container has a discontinuous screw-thread formed on the internal surface of a sidewall (18) of the cap (16) for co-operation with said thread (6) on the container (2), a removable latching member (24) being contained in said sidewall (18) to project substantially radially inwardly of the inner surface of the cap (16). In the closuring position of the cap (16) on the container (2), the latching member (24) co-operates with said abutment surface (14) to prevent unscrewing of the cap (16), removal of the latching member (24) from the cap (16) permitting unscrewing of the cap (16) from the container (2). <IMAGE>

Description

SPECIFICATION Tamperproof container and closure assembly This invention relates to tamperproof containers and closure assemblies and has particular, though not exclusive, application to relatively wide-mouthed jars.

It is now becoming relatively standard practice for sweetmeats of various kinds to be stocked in large, relatively wide-mouthed jars of a plastics material the mouths of the jars having screw-threads formed externally thereon and the jars being closed by means of caps of a plastics material provided with cooperating internal threads.

In order to ensure that jars are not opened and none of the contents are removed during transportation and delivery to a retailer, various proposals have been put forward to prevent removal of a cap from a jar without the fact that the cap has been removed being visually apparent.

Perhaps the most successful of these proposals from the practical viewpoint is the provision of a removable circumferential tear band between the cap and an annular retaining sleeve surrounding the mouth of the jar below the cap. Initiaily the tear band is moulded to be integral with both the cap and the sleeve. Only after removal of the band from the assembly can the cap be unscrewed from the jar. That the band has been removed is visually obvious, thus indicating if there has been any pilfering from the jar.

However, such an arrangement requires the use of substantial quantities of additional plastics material and, in particuiar, involves substantial tooling costs for producing the relatively complex closure required. Clearly this all adds to the cost of the container and closure assembly.

It would be desirable to be able to provide a container and closure assembly which was effective against tampering, gave a visual indication if tampering had occurred and which was cheaper to produce than the aforementioned arrangement.

According to the present invention there is provided a tamperproof container and closure assembly comprising a container around the mouth of which is formed at least a partial screw-thread, and a cap for said container provided with at least apartial internal thread for co-operation with said thread on the container, the circumferential sidewall of the cap including a removable latching member projecting substantially radially inwardly of the inner surface of said cap, and the mouth of the container being provided with an abutment surface such that, with the cap in an operative position closing the container, the latching member co-operates with said abutment surface to prevent unscrewing of the cap from the container, removal of the latching member from the cap permitting unscrewing of said cap from the container.

Conveniently the latching member is located in an aperture formed in the sidewall of the cap, the latching member being of generally wedge shape and including an end wall having a surface projecting substantially radially inwardly of the cap and in a plane extending longitudinally of the assembly for engagement with said abutment surface on the mouth of the container.

In a preferred embodiment, a buttress member is formed on the mouth of the container, said buttress member being of generally wedge shape, increasing in depth circumferentially of the container from a region at one end thereof on the mouth of said container to define an abutment surface on the other end thereof projecting substantially radially outwardly of the mouth of the container and in a plane extending longitudinally of the assembly.

The part of the mouth of the container adjacent the abutment surface on the buttress member may be indented relative to the remainder of the mouth of the container to define a recess for receiving the latching member and to increase the depth of said abutment surface on the mouth of the container.

Preferably the latching member is connected to the cap by thin webs of material extending between the latching member and opposed, circumferentially-extend ing sidewalls of the aperture in the cap.

Conveniently the latching member is provided with a gripper portion projecting outwardly therefrom, removal of the latching member from the cap being achieved by pulling on said gripper portion in a direction substantially tangentially of the cap to tear said thin webs of material. In such an arrangement, it is preferred that said gripper portion projects from the end of the latching member remote from said end wall engaging the abutment surface on the mouth of the container.

Preferably the screw-thread on the mouth of the container is discontinuous and includes an extent above the abutment surface on said mouth of the container. It is further preferred that the screw-thread on the cap is discontinuous and includes an extent above the latching member for co-operation with said extent above the abutment surface on the mouth of the container.

Conveniently the lower edge extent of part at least of the thread on the container and/or the upper edge extent of part at least of the thread on the cap are cut away to provide cooperating surfaces on said threads whichengage with one another to prevent axial removal of the cap from its operative position on the container, said threads being such as to enable the cap to be a push-ffit or a screwthreaded fit into the operative position on the container.

A plurality of circumferential strengthening ribs may be provided around the mouth of the container, while the underside of the top wall of the cap may be provided with a series of arcuate ribs defining together with the sidewall of the cap, a series of narrow, arcuate channels in which is received and located the upper end of the mouth of the container when the cap is in its operative position on said container.

By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig. 1 is a side view of the top part of a container and a cap of an assembly according to the invention; Fig. 2 is a horizontal section on the line ll-ll of Fig. 1; Fig. 3 is a horizontal section on the line Ill- Ill of Fig. 1, and Fig. 4 is a part vertical section on the line IV-IV of Fig. 1.

Referring to the drawings, the illustrated assembly comprises a transparent moulded plastics container 2 including a relatively wide mouth portion 4. A discontinuous thread comprising equally spaced portions 6 each extending over about 45 of the circumference of the container is formed externally around said mouth portion 4. Also formed around the mouth portion 4 are a series of circumferential ribs 8 which add strength to the mouth portion and prevent it collapsing as easily as it would without said ribs.

A rectangular indent 10 is formed in the mouth portion 4, the ribs 8 being discontinued over said indent 10, and a buttress member 1 2 is moulded into the mouth portion 4 in the form of a wedge adjacent the indent 10. More particularly the buttress member 12, considered in the circumferential direction of the mouth portion 4, tapers outwardly of said portion 4 towards the indent 10 whereby the end wall of the member 1 2 forms a continuation of an end wall of the indent to provide a flat abutment surface 14 extending radially outwardly of the mouth portion 4 and in a plane extending longitudinally of the container. A portion 6 of the thread is located directly above the indent 10 and buttress member 1 2.

The container 2 is closed by means of a moulded plastics cap indicated generally at 1 6 and has a discontinuous thread formed on the internal surface of the sidewall 18 of the cap for co-operation with the thread on the mouth of the container, said thread on the cap 1 6 comprising equally spaced extents 20.

A rectangular aperture 22 is formed through said sidewall 18 of the cap 16, a latching member 24 of plastics material being located in said aperture 22. A thread extent 20 is provided immediately adjacent the aperture 22.

More particularly, the latching member 24 is of generally wedge-shape in horizontal section, including an outer wall substantially flush with the sidewall 1 8 of the cap 16 and an end wall 26 projecting substantially radially inwardly of the internal surface of the sidewall 1 8. The latching member 24 is attached to the upper and lower edge of the rectangular aperture 22 by thin webs 28 of plastic, the length of the member 24 being just less than the length of the aperture 22 and just less than the length of the indent 10 in the mouth portion 4 of the container 2 for reasons which will become apparent. A gripper portion or handle 30 is formed on the member 24 to project outwardly from the cap 16.

Four equally-spaced arcuate locating flanges 32 are moulded on, to project downwardly from, the undersurface of the top wall of the cap 16, said flanges defining, together with the sidewall 18 of the cap 16, channels 34 for receiving associated extents of the top of the mouth portion 4 of the container 2 when the cap is on the container as will be detailed below.

Initial closure of the container 2 by the cap 1 6 is achieved by locating the cap 16 on top of the container 2 with the threaded extents 6 and 20 of the container and cap misaligned and with the latching member located to the side of the buttress member 1 2 remote from the indent 10. In this position, the cap can be pushed fully over the mouth portion 4 of the container with the upper edge of said mouth portion 4 of the container received in, to be located by, the channels 34 on the cap 16.

The cap is then turned in a clockwise direction on the container to bring the thread extents 6 and 20 into co-operating engagement, during which movement the latching member 24 rides up and over the buttress member to be received within the indent 10, the end wall 26 of the latching member 24 then lying adjacent the abutment surface 14 on the mouth portion 4 and defining the fully closed position of the container. It will thus be appreciated that reverse rotation of the cap 1 6 to remove it from the container 2 is prevented by abutment of said end wall 26 with the surface 14, while the lower edges of the thread extents 6 and the upper edges of the thread extents 20 are shaped to co-operate and prevent axial removal of the cap 1 6 from the container 2. Further, the provision of the strengthening ribs 8 on the mouth portion 4 of the container 2, together with the location flanges 32 on the cap 16, prevent any significant distortion of the mouth portion 4 as could possibly facilitate removal of the cap 1 6 from the container 2, while the provision of co-operating thread extents 6,20 immediately adjacent and above the the member 24 adds to the rigidity of the assembly.

In order to enable the cap 16 to be unscrewed from the container 2, it is necessary to remove the latching member 24 from the cap 16. This is achieved by pulling on the handle 30 in the direction of arrow 'A' in Fig.

2 substantially tangentially of the cap~16 whereby the thin webs 28 attaching the member 24 to the cap 1 6 are torn and the latching member 24 and handle 30 become detached from the cap 1 6. The cap can then be unscrewed to disengage the thread extents 6 and 20 and then removed axially from the container 2.

It will be appreciated that removal of the latching member 24 from the cap is visually obvious and makes it clear whether or not access has been made to the content of the container.

Although the described assembly incorporates a latching member 24 of generally wedge shape, various other shapes could be used with equal effect providing the necessary abutment with the mouth portion 4 of the container 2 is achieved.

For example, and particularly in containers of fairly rigid construction where distortion of the buttress member is unlikely to occur to any great extent, the latching member may comprise a cylindrical member located in the aperture in the sidewall of the cap, the axis of the cylinder extending substantially circumferentially of the cap and perpendicular to the central longitudinal axis of the assembly, part of said cylinder projecting inwardly of the inner surface of the cap and the ends of said cylinder being secured to the cap by thin webs of material.

In one embodiment of this type, the cylindrical member may comprise a hollow body portion and a pair of opposed, circular end plates, part of the body portion projecting inwardly of the aperture in the cap being cut away to present the hollow interior of the member to the indent in the mouth of the container. Alternatively, the cylindrical member could comprise a solid disc.

The webs of material by which the cylindrical member is secured to the cap may be such that, on rotation of said member about its central axis and relative to the cap, said webs break to permit removal of the member from the cap. Preferably the nature of the webs is such that rotation in excess of 360' results in breakage of said webs.

While the preferred application of the invention is to plastic sweet jars, said invention has application to container and closure assemblies for a variety of different contents.

Claims (17)

1. A tamperproof container and closure assembly comprising a container around the mouth of which is formed at least a partial screw-thread, and a cap for said container provided with at least a partial internal thread for co-operation with said thread on the container, the circumferential sidewall of the cap including a removable latching member projecting substantially radially inwardly of the inner surface of said cap, and the mouth of the container being provided with an abutment surface such that, with the cap in an operative position closing the container, the latching member co-operates with said abutment surface to prevent unscrewing of the cap from the container, removal of the latching member from the cap permitting unscrewing of said cap from the container.

2. An assembly as claimed in claim 1 in which the latching member is located in an aperture formed in the sidewall of the cap, the latching member being of generally wedge shape and including an end wall having a surface projecting substantially radially inwardly of the cap and in a plane extending longitudinally of the assembly for engagement with said abutment surface on the mouth of the container.

3. An assembly as claimed in claim 1 or claim 2 in which a buttress member is formed on the mouth of the container, said buttress member being of generally wedge shape, increasing in depth circumferentially of the container from a region at one end thereof on the mouth of said container to define an abutment surface on the other end thereof projecting substantially radially outwardly of the mouth of the container and in a plane extending longitudinally of the assembly.

4. An assembly as claimed in claim 3 in which the part of the mouth of the container adjacent the abutment surface on the buttress member is indented relative to the remainder of the mouth of the container to define a recess for receiving the latching member and to increase the depth of said abutment surface on the mouth of the container.

5. An assembly as claimed in any one of claims 2 to 4 in which the latching member is connected to the cap by thin webs of material extending between the latching member and opposed, circumferentially-extending sidewalls of the aperture in the cap.

6. An assembly as claimed in claim 5 in which the latching member is provided with a gripper portion projecting outwardly therefrom, removal of the latching member from the cap being achieved by pulling on said gripper portion in a direction substantially longitudinally of the cap to tear said thin webs of material.

7. An assembly as claimed in claim 6 in which said gripper portion projects from the end of the latching member remote from said end wall engaging the abutment surface on the mouth of the container.

8. An assembly as claimed in any one of claims 1 to 7 in which the screw-thread on the mouth of the container is discontinuous and includes an extent above the abutment surface on said mouth of the container.

9. An assembly as claimed in claim 8 in which the screw-thread on the cap is discontinuous and includes an extent above the latching member for co-operation with said extent above the abutment surface on the mouth of the container.

10. An assembly as claimed in any one of claims 1 to 9 in which the lower edge extent of part at least of the thread on the container and/or the upper edge extent of part at least of the thread on the cap are cut away to provide co-operating surfaces on said threads which engage with one another to prevent axial removal of the cap from its operative position on the container, said threads being such as to enable the cap to be a push-fit or a screw-threaded fit into the operative position on the container.

11. An assembly as claimed in any one of claims 1 to 10 in which a plurality of circumferential strengthening ribs are provided around the mouth of the container.

1 2. An assembly as claimed in any one of claims 1 to 11 in which the underside of the top wall of the cap is provided with a series of arcuate ribs defining, together with the sidewall of the cap, a series of narrow, arcuate channels in which is received and located the upper end of the mouth of the container when the cap is in its operative position on said container.

1 3. An assembly as claimed in claim 1 in which the latching member is located in an aperture formed in the sidewall of the cap,-the latching member comprising a cylindrical member the axis o & which extends substantially circumferentially of the cap and perpendicular to the central longitudinal axis of the assembly, part of said cylinder projecting inwardly of the inner surface of the cap and the ends of said cylinder being secured to the cap by thin webs of material.

14. An assembly as claimed in claim 1 3 in which the cylindrical member comprises a hollow body portion and a pair of opposed, circular end plates, part of the body portion projecting inwardly of the aperture in the cap being cut away to present the hollow interior of the member to the indent in the mouth of the container.

1 5. An assembly as claimed -in claim 1 3 in which the cylindrical member comprises a solid disc.

16. An assembly as claimed in any one of claims 1 3 to 1 5 in which the webs of material by which the cylindrical member is secured to the cap are such that, on rotation ofsaid member about its central axis and relative to the cap, said webs break to permit removal of the member from the cap.

17. A tamperproof container and closure assembly substantially as described with reference to and as illustrated by the accompanying drawings.