GB2118153A

GB2118153A - Containers

Info

Publication number: GB2118153A
Application number: GB08309070A
Authority: GB
Inventors: Ernest Porter Prebble
Original assignee: STERIPAK Ltd
Current assignee: STERIPAK Ltd
Priority date: 1982-04-15
Filing date: 1983-03-31
Publication date: 1983-10-26

Abstract

A container 10 of plastics material for sterile fluids has its neck 12 closed by a top, (not shown) attached thereto by a membrane of plastics material. The neck has a circumferential or other protrusions 20 so as to stretch and pierce the membrane when the top is forced downwardly by a cap screwed onto a screw threaded portion 13 of the neck 12. Alternatively the top can be shaped so as to cause the stretching and piercing above mentioned. <IMAGE>

Description

SPECIFICATION Containers This invention concerns containers of plastics material suitable for sterile fluids.

A known sterile container of plastics material is formed by moulding with an open neck, filling with sterilised fluid and sealing by joining of a moulded top to the open neck of the container by a plastics membrane. To open the container, a cap is provided which when screwed down onto the container forces the moulded top downwards thus rupturing the membrane. The cap is designed to retain the moulded top and so unscrewing of the cap removes the top leaving the container open.

This arrangement is satisfactory at normal room temperatures e.g. 200C. However it is often preferred, when the sterile fluid is used for washing hospital patients, that the fluid be warm.

Thus, when the container is being opened it often happens that the membrane stretches rather than ruptures. The container then either has to be discarded or opened in some other way, say with a knife. Therefore, the known containers are not really suitable if the sterile fluid is to be used warm.

The object of this invention is to provide a plastics container suitable for sterile fluids which can be opened even when warm.

According to this invention there is provided a container of plastics material having its neck closed by a top attached thereto by a membrane of plastics material, wherein the neck or the top is shaped so as to stretch and pierce or rupture the membrane when the top and container are forced together by a cap screwed onto a screw threaded portion thereof.

The top is conveniently attached to an extension of the neck above the screw-threaded portion, preferably to the rim thereof. The top preferably has an inturned circumferential lip, the diameter of its innermost edge being substantially the same as that of the outer edge of the lesser diameter portion of the container neck. The membrane preferably holds the top and container neck together with the innermost edge of the top and the outer edge of the rim of the container neck adjacent.

The shaping required to stretch and pierce or rupture the membrane may be one or more protrusions on the container neck just below the point of attachment of the top. For example, one or more circumferentially arranged protrusions may be suitable, such as a continuous circumferential protrusion or a series of segmental protrusions. Alternatively the protrusions may be axially arranged, such as upwardly pointing arrow shapes of decreasing depth to the points thereof or protrusions of substantially V-section in parallel arrangement around the neck after the manner of splining or in discrete sections.

Alternatively the top may be shaped to cause stretching and piercing or rupturing of the membrane for example by means of inwardly directed protrusions of the top above its circumferential lip.

This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a conventional container neck and top; Figure 2 shows a first shaped container neck; Figure 3 shows a second shaped container neck; Figure 4 shows a third shaped container neck; Figure 5 shows a fourth shaped container neck; Figure 6 shows a first shaped container top; and Figure 7 shows a second shaped container top.

Referring to Figure 1, a container 10 has a neck with a lower screw threaded portion 13 for attachment of a correspondingly screw threaded closure means (not shown). Upper portion 14 of the neck 12 is plain and is surmounted by a top 1 5 having an inturned lip 18. The lip of the top 1 5 is attached to the upper edge of the container neck by a membrane 1 9 of plastics material. In use, a closure means is screwed down onto the container neck forcing the top down thus stretching and hopefully rupturing the membrane 19. Since the membrane 1 9 does not always rupture in practice shaping of the container neck such as in Figures 2 to 5 is proposed which shaping can cause greater stretching and hence rupturing of the membrane.

In Figure 2, the upper portion 14 of the container neck 12 has a circumferential protrusion 20 that increases in diameter upwards of the neck 12. Figure 3 shows a modification of Figure 2 in that instead of a continuous circumferential protrusion, a series of segmental protrusions 40 is provided on the upper portion 14 of the container neck 12. In Figure 4, the upper portion 14 of the container 12 has upwardly direction arrow-like protrusions 22 which increase in depth radially downwards of the neck 12. In Figure 5 the upper portion 14 of the container neck 12 has spline-like protrusions 23 of substantially constant radial depth.

Alternatively, the container top 1 5 may be shaped as in Figure 6 wherein sloping protrusions 25 are provided above the lip 18 or as in Figure 7 wherein inwardly directed splining 30 is formed on the inside of the top 1 5.

Claims

1. A container of plastics material having its neck closed by a top attached thereto by a membrane of plastics material, wherein the neck or top is shaped so as to stretch and pierce or rupture the membrane when the top and container are forced together by a cap screwed onto a screw threaded neck portion.

2. A container as claimed in claim 1 wherein the top is attached to an extension of the neck above the screw threaded portion.

3. A container as claimed in claim 2 wherein

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Containers This invention concerns containers of plastics material suitable for sterile fluids. A known sterile container of plastics material is formed by moulding with an open neck, filling with sterilised fluid and sealing by joining of a moulded top to the open neck of the container by a plastics membrane. To open the container, a cap is provided which when screwed down onto the container forces the moulded top downwards thus rupturing the membrane. The cap is designed to retain the moulded top and so unscrewing of the cap removes the top leaving the container open. This arrangement is satisfactory at normal room temperatures e.g. 200C. However it is often preferred, when the sterile fluid is used for washing hospital patients, that the fluid be warm. Thus, when the container is being opened it often happens that the membrane stretches rather than ruptures. The container then either has to be discarded or opened in some other way, say with a knife. Therefore, the known containers are not really suitable if the sterile fluid is to be used warm. The object of this invention is to provide a plastics container suitable for sterile fluids which can be opened even when warm. According to this invention there is provided a container of plastics material having its neck closed by a top attached thereto by a membrane of plastics material, wherein the neck or the top is shaped so as to stretch and pierce or rupture the membrane when the top and container are forced together by a cap screwed onto a screw threaded portion thereof. The top is conveniently attached to an extension of the neck above the screw-threaded portion, preferably to the rim thereof. The top preferably has an inturned circumferential lip, the diameter of its innermost edge being substantially the same as that of the outer edge of the lesser diameter portion of the container neck. The membrane preferably holds the top and container neck together with the innermost edge of the top and the outer edge of the rim of the container neck adjacent. The shaping required to stretch and pierce or rupture the membrane may be one or more protrusions on the container neck just below the point of attachment of the top. For example, one or more circumferentially arranged protrusions may be suitable, such as a continuous circumferential protrusion or a series of segmental protrusions. Alternatively the protrusions may be axially arranged, such as upwardly pointing arrow shapes of decreasing depth to the points thereof or protrusions of substantially V-section in parallel arrangement around the neck after the manner of splining or in discrete sections. Alternatively the top may be shaped to cause stretching and piercing or rupturing of the membrane for example by means of inwardly directed protrusions of the top above its circumferential lip. This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a conventional container neck and top; Figure 2 shows a first shaped container neck; Figure 3 shows a second shaped container neck; Figure 4 shows a third shaped container neck; Figure 5 shows a fourth shaped container neck; Figure 6 shows a first shaped container top; and Figure 7 shows a second shaped container top. Referring to Figure 1, a container 10 has a neck with a lower screw threaded portion 13 for attachment of a correspondingly screw threaded closure means (not shown). Upper portion 14 of the neck 12 is plain and is surmounted by a top 1 5 having an inturned lip 18. The lip of the top 1 5 is attached to the upper edge of the container neck by a membrane 1 9 of plastics material. In use, a closure means is screwed down onto the container neck forcing the top down thus stretching and hopefully rupturing the membrane 19. Since the membrane 1 9 does not always rupture in practice shaping of the container neck such as in Figures 2 to 5 is proposed which shaping can cause greater stretching and hence rupturing of the membrane. In Figure 2, the upper portion 14 of the container neck 12 has a circumferential protrusion 20 that increases in diameter upwards of the neck 12. Figure 3 shows a modification of Figure 2 in that instead of a continuous circumferential protrusion, a series of segmental protrusions 40 is provided on the upper portion 14 of the container neck 12. In Figure 4, the upper portion 14 of the container 12 has upwardly direction arrow-like protrusions 22 which increase in depth radially downwards of the neck 12. In Figure 5 the upper portion 14 of the container neck 12 has spline-like protrusions 23 of substantially constant radial depth. Alternatively, the container top 1 5 may be shaped as in Figure 6 wherein sloping protrusions 25 are provided above the lip 18 or as in Figure 7 wherein inwardly directed splining 30 is formed on the inside of the top 1 5. Claims

3. A container as claimed in claim 2 wherein the top is attached to the rim of the neck extension.

4. A container as claimed in claim 3 wherein the top has an inturned circumferential lip, the diameter of its innermost edge being substantially the same as that of the outer edge of the neck rim.

5. A container as claimed in claim 4 wherein the membrane holds the top and container neck together with the innermost edge of the top and the outer edge of the neck rim adjacent.

6. A container as claimed in any one of claims 1 to 5 wherein the shaping comprises one or more protrusions of the container neck below the attachment of the top.

7. A container as claimed in claim 6 wherein the shaping is a continuous circumferential protrusion of the neck.

8. A container as claimed in claim 6 wherein the shaping is a plurality of segmental protrusions of the neck.

9. A container as claimed in claim 6 wherein the shaping comprises one or more axial protrusions of the neck.

1 0. A container as claimed in claim 9 wherein the shaping comprises upwardly pointing arrow shapes of increasing depth away from their point.

1 A container as claimed in claim 9 wherein the shaping comprises protrusions of substantially V-cross section in generally parallel arrangement about the neck.

12. A container as claimed in any one of claim 1 to 5 wherein the shaping comprises one or more inwardly directed protrusions of the top above its circumferential lip.

1 3. A container substantially as hereinbefore described with reference to and as illustrated in any one of Figures 2 to 7 of the accompanying drawings.