DRUM CLOSURE

Abstract: A closure (16) for external attachment to an upturned flange (13) on a drum or like container. The container has an outer crimping flange (17) for crimping about the upturned flange, a threaded neck (20) and a connecting web (23) integrally connecting the crimping flange and the neck. The closure and drum have co-operating means (15, 18) for preventing rotation of the closure when crimped on. A closure and container assembly and a method of filling and sealing a container using the closure are also described and claimed.

Description: DRUM CLOSURE This invention relates to improvements in closures for containers, such as pails, drums and the like. In a known form of closure for metal containers, such as pails and drums of the type commonly used for the shipment and storage of oil and other liquids, there is provided a neck which defines a filling or pouring hole in one end wall or head of the container and an externally threaded plug or internally threaded cap adapted to seat upon and be secured to the neck to close and seal the hole. This form of closure is open to objection in that the small diameter of the filling hole restricts the speed with which the container can be filled. U.S. Patent No. 4625889 (Baughman) discloses a closure assembly adapted for fitting to a synthetic material drum having a thick, internally splined annular boss. The closure consists of a synthetic material member having an annular channel to receive the boss, and an externally splined flange receivable within the boss. The inner surface of the flange is threaded to receive a standard two-inch closing plug, and the closure is secured to the drum with a metal crimping ring. The splined flange of the Baughman closure is closely received within the boss, and thus the additional area available for filling before fitting the closure is small, with the difference in the area arising only from the thickness of the flang°. Also, this closure relies on a close fit over the thick drum boss for strength, and is not suitable for use with metal drums or other containers having a relatively thin upturned flange. Furthermore, without engagement with the splines on the thick drum boss, the Baughman closure is unable to withstand torque applied during insertion and removal of the plug or threaded dispensing pumps, with either the whole closure rotating relative to the drum or the synthetic material portion rotating relative to the crimping ring. The present invention aims to provide a closure which may be secured to a container after filling, and which overcomes at least some of the disadvantages of the prior art. In one broad form, the present invention provides a closure adapted for external attachment to a container wall, the wall having an upstanding flange which surrounds an opening, the closure comprising: an outer crimping flange adapted for crimping about the upstanding flange; a threaded neck having a longitudinal axis which defines an axis of rotation for a closure plug, said neck being spaced towards said axis from the crimping flange and adapted in use to be spaced towards said axis from said upstanding flange; a connecting web integrally connecting the crimping flange and the neck; and means adapted to prevent rotation of the closure. In another form, the invention provides a method of filling a container with a flowable material, comprising introducing a desired amount of the material into the container through an opening in a container wall, the opening being surrounding by an upstanding flange, and subsequently attaching a closure according to the present invention by crimping the crimping flange about the upstanding flange. Preferably, a threaded sealing plug is engaged with the neck of the closure prior to the attachment of the closure. Yet further forms of the invention relate to a container and closure assembly. In one preferred form of the invention, the crimping flange, neck and web form a downwardly opening channel adapted to receive the flange on the container wall. Preferably, the crimping flange includes the means for preventing rotation of the closure when the closure is crimped on. In one preferred form, the crimping flange may have one or more cut-out portions along its bottom edge which may be aligned with corresponding raised portions on the drum end wall to prevent rotation. Alternatively, the crimping flange and the upstanding flange on the container may be non-circular, for example approximately elliptical, or the upstanding flange and the closure may be staked by a series of indents formed during or after the crimping operation. Further preferred embodiments of the invention are illustrated in the accompanying drawings, in which: Figure 1 is an elevation, partly in cross-section, of a first closure according to the invention; Figures 2 and 3 are plan and side views respectively of a portion of a drum end wall for receiving the closure of Fig. 1; Figure 4 is a partial cross section of the closure of Figs. 1 when crimped onto the drum end wall of Figs. 2 and 3 ; and Figure 5 is a plan view of a second closure according to the invention. Referring to Figs. 1 to 4, a metal drum has an end wall 11 having a circular opening 12 surrounded by an upturned flange 13 which is formed as a reverse curl 14. The end wall 11 also has a pair of raised portions 15 pressed therein. In use, the container is positioned with opening 12 under a filling nozzle or the like and the container is filled. A closure 16 is then placed over opening 11 such that the outer crimping flange 17 of the closure closely receives the drum flange 13 and the closure is spun about its axis until two of the four cut-out sections 18 in the bottom of the crimping flange receive the raised portions 15 on the end wall 11. A crimping tool then is used to crimp flange 17 onto the curl 14, thus locking the closure onto gasket 19 as shown in Figure 4 to prevent leakage of the contents. The use of gasket 19 between the closure 16 and the drum flange 13 ensures that used or damaged closures can be removed without damaging the flange cross-section. This will allow for closures to be fitted more than once to the same drum without affecting the integrity of the seal. The closure 16 has an internally threaded neck 20 which receives a standard two-inch sealing plug 21 with gaskets 22 to prevent leakage. A connecting web 23 integrally connects the outer crimping ring 17 and the neck 20.In order to achieve efficient filling and sealing of the drum, the plug would normally be in position in the closure prior to fitting the closure onto the drum. To access the contents of the drum, a user merely unscrews and removes the externally threaded plug 11. The engagement of two of the cut-outs 18 with raised sections 15 ensures that the closure 16 cannot rotate with the plug. The contents may then be removed by pouring, pumping or any other suitable method. The closure neck does not protude below the level of the drum end wall, and thus the closure does not entrap a large reservoir of liquid when the drum is inverted for emptying. The cavity between the drum flange 13 and the closure 16 may be eliminated by an extension 19a of gasket 19 to fill the cavity as shown in Fig. 4 further to reduce the amount of liquid retained in the drum after emptying by inversion. Alternatively, this cavity may be eliminated by redesign of the closure. In a second embodiment, rotation of the closure is prevented by making the crimping ring 17a and the drum flange 15 non-circular, for example approximately elliptical as illustrated in Fig. 5. Of course, the threaded neck 20 is circular for receiving the threaded plug 21. Preferably, the connecting web of the closure is formed from thicker guage or stronger material then the crimping flange. This gives the closure sufficient srength to resist damage when a pump or the like is screwed into the closure neck and used as a to mce the drum, and allows crimping of the closure onto the drum flange without the need to bear against the inside of the drum flange, thus negating the need for an interference fit which requires the application of enormous pressure. hile the illustrated closure is adapted for manufacture by machining, it will be appreciated that the closure may be formed by stamping or any other suitable method. The closure need not be unitary in construction and may, for example, be formed from two integrally joined metal stampings. Such a construction allows greater metal thickness to be employed in parts of the closure which are subjected to greater stress, while retaining the cost advantages of mass manufacture by stamping. The present invention allows rapid filling of containers through a larger diameter filling hole while retaining a conventional threaded neck for receiving conventional plugs, pumps and other accessories. This in turn facilitates the use of high speed filling machinery for large containers. For example, a closure for attachment to a 3 inch drum flange and having a standard 2 inch internally threaded neck offers an increased filling area of over 100%. Another advantage of the closure of the present invention is that the closure is readily adapted to an all-metal construction, with the exception of the gaskets. This allows the container to withstand considerable physical abuse during handling and filling without the integrity of the container end wall and the seal being compromised. The closure also demonstrates a high resistance to torque applied during insertion and removal of the plug or dispensing pump. While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in othe specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, with the scope of the invention being as defined in the claims. For example, the diameter of the closure and the manner of preventing rotation of the closure may be varied to suit the type of container and the equipment to be used for filling the container.

Claims: CLAIMS 1. A closure adapted for external attachment to a container wall, the wall having an upstanding flange which surrounds an opening, the closure comprising: an outer crimping flange adapted for crimping about the upstanding flange; a threaded neck having a longitudinal axis which defines an axis of rotation for a closure plug, said neck being spaced towards said axis from the crimping flange and adapted in use to be spaced towards said axis from said upstanding flange; a connecting web integrally connecting the crimping flange and the neck; and means adapted to prevent rotation of the closure. 2. A closure according to claim 1 wherein the crimping flange, neck and web form a downwardly opening channel adapted, in use, to receive the upstanding flange of the container wall. 3. A closure according to claim 2 further comprising a gasket which, in use, substantially occupies the space between the upstanding flange and the neck. 4. A closure according to claim 1 wherein, in use, the neck does not project into the container past the level of the container wall. 5. A closure according to claim 1 wherein the crimping flange has said means for preventing rotation . 6. A closure according to claim 5 wherein said prevention means comprise recesses on the crimping flange adapted to receive raised portions on the container wall. 7. A closure according to claim 6 wherein said recesses comprise cut out portions along a bottom edge of the crimping flange. 8. A closure according to claim 5 wherein the crimping flange and upstanding flange are non-circular. 9. A closure according to claim 8 wherein the crimping flange and upstanding flange are approximately elliptical. 10. A container and closure assembly comprising: a container including a wall having an upstanding flange which surrounds an opening; a closure attached externally to the container, comprising an outer crimping flange crimped about said upstanding flange, a threaded neck having a longitudinal axis which defines an axis of rotation for a closure plug, said neck being spaced towards said axis from said crimping flange and said upstanding flange, and a connecting web integrally connecting said crimping flange and said neck; and means preventing rotation of the closure. 11. An assembly according to claim 10 wherein the crimping flange, neck and web of the define a downwardly opening channel which receives the upstanding flange. 12. An assembly according to claim 12 wherein the space between upstanding flange and neck is substantially occupied by a gasket. 13. An assembly according to claim 11 wherein neck does not project into the container past the level of the container wall. 14. An assembly according to claim 11 wherein said means for preventing rotation comprises engaged formations on the crimping ring and the container. 15. An assembly according to claim 14 wherein the formations comprise recesses on the crimping ring which receive raised portions on the container wall. 16. An assembly according to claim 11 wherein the crimping ring and the upstanding flange are non-circular. 17. A method of filling and sealing a container, said container including a wall having an opening surrounded by an upstanding flange, the method comprising: filling said container through said opening with a desired amount of a flowable material; and subsequently sealing the container by attaching a closure according to claim 1 by crimping the crimping flange of the closure about the upstanding flange of the container. 18. A method according to claim 17 wherein a closure plug is engaged in the neck of the closure prior to attaching the closure to the container. 19. A method according to claim 17 wherein the sealing step comprises engaging corresponding means on the crimping flange and the container for preventing rotation of the closure. 20. A method according to claim 19 wherein the engagement of said corresponding prevention means comprises aligning the corresponding prevention means on the container and the closure prior to crimping. 21. A method according to claim 20 comprising aligning corresponding recesses in the crimping flange and raised portions in the container wall. 22. A method according to claim 19 wherein the crimping flange and the upstanding flange are non-circular. 23. A method according to claim 20 wherein the crimping ring and the upstanding flange are approximately elliptical.

Inventors: LYNCH GARY DESMOND, LYNCH, GARY, DESMOND
Applicants: WEIR & HARROD MACHINERY PTY LI, WEIR & HARROD MACHINERY PTY. LIMITED
Application year: 1991
Main classification: B65D39
IPC codes: B65B7, B65D39