AU775389B2 - Drum closure - Google Patents

Description

.1

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): ne(~~T j4ukhthajrki V- or(Asrla Pty Ltd A.C.N. 008 415 478 Invention Title: DRUM~ CLOSURE The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 DRUM CLOSURE The present invention relates to a drum closure, particularly for insertion into a pre-formed aperture in an end wall of a drum.

Typically the opening in a drum end wall is offset relative to the centre. One common form of closure provides a coarsely threaded nozzle which is crimped in sealing engagement with a metal ring which itself is crimped to an upstanding collar portion around the opening in the end wall before the end wall is crimped to the drum body. The drum passes along a production line where it is filled through the open nozzle, eg with 20 litres of product. A screw cap then needs to be applied. An industry standard is a closure nozzle of 56mm. Screw threaded attachments such as dispensing pumps are in most widespread use and are adapted to fit such nozzles.

For the class of nozzles in question, there has been a long-standing problem in that no manufacturer has provided such a nozzle which contains a tamper-evident seal and is a closure which is adapted to be fitted with automatic machinery on a production line after drum filling. Embodiments of the invention offer a solution.

The present invention consists in a closure for fitting to an opening in a drum end wall of a drum, the closure including an inner element, a metal ring adapted to fit over a peripheral portion of the inner element and having a skirt portion which crimps to an upstanding collar defining an opening in the drum end wall, (ii) a screw threaded upstanding nozzle extending from the ring and a closure cap screw-fitted to the nozzle, the inner element providing a flexible diaphragm extending within the drum closure at a position adjacent to the inner surface of the closure cap, (ii) the 40971 3 diaphragm having a gripping element which is exposed when the closure cap is removed to permit the diaphragm to be ruptured and removed to provide access to the container and (iii) an upstanding support element which has an upper surface in abutment with or closely adjacent to the interior of the closure cap whereby a slight deflection of the diaphragm due to pressurisation from within the drum causes the diaphragm to be supported by the interior of the screw cap.

Preferably the inner element is a flexible element shaped to facilitate fitting of the closure to the opening and to prevent contact of contents of the drum with other components of the closure.

Preferably the inner element is of plastic material and has a multiplicity of depending fingers which have a radially inwardly directed external form towards the lower end thereof so as to centre the closure when dropped into position over the opening in a drum end wall prior to S. crimping the metal ring to the collar.

20 In preferred embodiments, the inner element acts as a liner to protect fully the contents of the container from S•contacting any of the metal parts of the closure prior to rupturing of the diaphragm, the inner element having the peripheral portion profiled to snap-fit into the metal ring.

An embodiment of the invention will now be described with reference to the accompanying drawings, of which: Fig. 1 is a plan view of a drum end wall for receiving a drum closure embodying the invention; Fig. 2 is a cross sectional view taken along the line II-II of Fig. 1 and showing the form of the opening for the closure device, on an enlarged scale; 40971 4 Fig. 3 is a view on a much enlarged scale of portion A of Fig. 2; Fig. 4 is a cross sectional elevation through a preferred embodiment of drum closure according to the present invention; Fig. 5 is a plan of the plastic inner element of the drum closure in Fig. 4; Fig. 6 is an inverted plan view of the element of Fig. Fig. 7 is a cross-sectional elevation of the closure when installed on a drum end wall; and Fig. 8 is an enlarged view of portion B of Fig. 7.

The drum shown in Fig. 1 has an upper end wall having a central handle 11, and an eccentrically disposed opening 12 defined within an upstanding wall 13 shown in detail in Fig. 2 and Fig. 3. From Fig. 2 it will be seen that the flat drum end wall 14 is pressed with a shallow trough 15 which has to an upstanding wall 13 which leads to an inwardly extending curved collar 16. It will be noted that the upstanding wall 13 flares radially outwardly by about 15 9 S"As shown in Figures 4-8, the drum closure comprises a plastic lining and sealing element 20, a metal mounting ring 21, an upstanding screw-threaded nozzle 22 crimped to 25 the ring 21, and a screw-threaded closure cap 23 which has a soft plastic sealing disk 24 fitted within the cap.

The plastic element 20 is an integral part moulded in a soft plastic and comprises a multiplicity of fingers which depend downwardly from an annular base portion 26.

The annular base portion is surrounded by an upstanding outer wall of slightly outwardly diverging form which leads to a radially outwardly directed top wall 28, which 40971 in turn leads to a short skirt 29 which is downwardly depending and outwardly flared.

The annular base portion 26 has an inner upstanding wall 30 which leads to a transverse diaphragm 31 connected to the inwardly directed tip 38 of wall 30 by a reduced thickness and frangible portion.

The diaphragm 31 has an integrally formed gripping ring 33 and a collar 34 which extends around the diaphragm to support the diaphragm against the inner wall of the screw cap.

The ring 21 and nozzle 22 are sealingly crimped together at an overlapping joint 40 (see Figure 8) and the outer depending skirt 41 of the ring has an inwardly directed portion shaped and configured so that the plastic ring can snap-fit into the position shown in Figure 4.

Due to the tapering form of the fingers 25, the assembled product, complete with screw cap in position, can simply be dropped into the opening 12 in the drum after the drum has been filled. The fingers have a self- 20 centering function.

A conventional crimping tool can then be used to crimp inwardly the depending skirt 41 around the exterior of the wall 13 thereby establishing a seal. The finally assembled arrangement is shown in the views of Figures 7 and 8.

40971

Claims (6)

1. 3. A drum closure as claimed in claim 1 wherein the inner element is of plastic material and has a multiplicity of depending fingers which have a 40971 7 radially inwardly directed external form towards the lower end thereof so as to centre the closure when dropped into position over the opening in a drum end wall prior to crimping the metal ring to the collar.
2. 4. A drum closure as claimed in any one of the preceding claims wherein the inner element acts as a liner to protect fully the contents of the container from contacting the metal ring and closure cap prior to rupturing of the diaphragm, the inner element having a peripheral portion profiled to snap-fit into the metal ring. A drum closure as claimed in any one of the preceding claims wherein the upstanding element is a substantially annular upstanding wall.
3. 6. A drum closure as claimed in any one of the preceding claims, wherein the gripping element is a flexible ring integrally formed with and connected to the diaphragm near one radially outer edge.
4. 7. A drum closure substantially as herein described with reference to Figures 4-8 of the accompanying drawing.
5. 8. A drum end wall having an opening defined by an upstanding wall, and a drum closure as claimed in any one of the preceding claims connected to the end wall by crimping the metal ring of the closure to the upstanding wall.
6. 9. A drum having a drum and wall as claimed in claim 8 crimped to the drum body. 40971 8 A method of providing a filled drum comprising taking a drum having a drum end wall with an upstanding wall defining an opening, filling the drum through the opening, fitting a drum closure as claimed in any one of claims 1-7 to the opening and crimping the metal ring of the closure to the upstanding wall. o.. *oooo *oeo 40971