WO2001017707A1

WO2001017707A1 - A drum and method and apparatus for manufacturing a drum

Info

Publication number: WO2001017707A1
Application number: PCT/AU2000/001037
Authority: WO
Inventors: Grahame Colin Watson; Eric D Tierie
Original assignee: Huhtamäki Van Leer (Australia) Pty. Ltd.
Priority date: 1999-09-02
Filing date: 2000-09-01
Publication date: 2001-03-15
Also published as: AUPQ261199A0

Abstract

A method of manufacturing a drum (14), including: forming an open ended body (1); performing a first deforming process on the body to form a taper in a wall (5) of the body such that one end (2) of the body has a larger diameter than a second end (3) thereof; and performing a second deformation process on the body to substantially remove the taper. A drum (14) formed in accordance with the method and an apparatus (20) to perform the second deforming process are also provided.

Description

A DRUM AND METHOD AND APPARATUS FOR MANUFACTURING A DRUM

Field of the Invention

The present invention relates to a drum and method and apparatus for manufacturing a drum. Reference to a "drum" throughout the specification should be taken as a reference to any type of container which may be formed from sheet material, often being tin plate, steel or aluminium.

Background of the Invention

One type of drum which is formed from sheet metal is a parallel sided drum with closed ends, known in the industry as a "tight head" or "closed head" drum. The drum is formed by rolling a rectangular sheet of metal and welding the free edges of the sheet together to form a cylindrical body. The body is generally expanded to size and open ends of the body are sequentially flanged and fitted with respective covers which are seamed in place to form the top and bottom of the drum. The flange for the top of the drum is generally formed by reducing the diameter of the drum over an expanded chuck, adjacent the top end, and rolling a rim of the drum over to produce the flange. The top is generally provided with a one or more openings.

A second type of drum formed of sheet metal has tapered sides and is known in the industry as a "tapered open head" or "conical" drum. Such a drum is similarly formed by welding a rolled sheet of material into a cylindrical body however the body is subsequently deformed by expansion so that the body adopts a tapered configuration with one end being of a larger diameter than the other end. The larger diameter end forms an open top end of the drum and is provided with a curled over rim for receipt of a removable lid. The smaller diameter end is flanged and fitted with a cover which is seamed in place. Lugs may be attached to the drum for attachment of a handle.

As may be appreciated, a production facility producing both types of drum has a number of disadvantages in that the procedure for manufacturing each of the above described drums varies significantly and different production lines and tooling are required, not only to cater for different production steps but because generally each type of drum is formed from differently dimensioned metal sheet stock. Further, the tight head drum has a disadvantage in that stacking is not as efficient, as compared to the tapered open drums, which can nest within each other, and transport and storage costs are considerable.

Summary of the Invention

The present invention seeks to address at least one of the above disadvantages.

In accordance with one broad aspect of the invention, there is provided a method of manufacturing a drum including: forming an open ended body; performing a first deforming process on the body to form a taper in a wall of the body such that one end of the body has a larger diameter than a second end thereof; and performing a second deforming process on the body to substantially remove the taper.

Preferably, the first and second deforming processes comprise expansion processes.

Preferably, a cover is fitted to the second end of the body prior to the second deforming process, such as by seaming. A flange is preferably applied to the second end and a swedge is preferably formed in the wall of the body prior to fitting the cover.

As may be appreciated, following application of the cover and prior to the second deforming step, the body is in a form similar to a partially constructed conventional tapered open head drum and may be readily nested in other such drums for storage and transport to a second production facility where the second deforming process may be applied to form a tight head drum.

Preferably, the second deforming process includes expanding the body over a region of the wall extending from a location adjacent the second end toward the first end whereby to render sides of the wall substantially parallel.

Preferably, a second swedge is formed in the wall adjacent the second end.

Preferably, a second cover is fitted to the first end such as by seaming. In another aspect, there is provided a drum formed in accordance with the above described method.

In yet another aspect, there is provided apparatus for performing a deforming process on a partially formed drum having a tapered wall with an open first end of a diameter larger than a second end, which is fitted with a cover, the apparatus including an expansion device arranged to extend into the body and expand the body to substantially remove the taper and render sides of the wall substantially parallel.

Brief Description of the Drawings

The invention is described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 illustrates a first stage in producing a drum in accordance with the invention; and Figure 2 illustrates a second stage of production.

Figure 3 illustrates operation of an apparatus for performing the deforming process of the second stage of production.

Detailed Description of a Preferred Embodiment

Figure 1 illustrates a first stage in producing a drum in accordance with the invention. In Figure la. a body 1 of sheet metal is provided in a cylindrical form with first and second open ends 2,3 and a welded seam 4 connecting free ends of the sheet together. The body 1 is then subjected to a first deforming process so as to be expanded into a form shown in Figure lb. where the first end 2 has a larger diameter than the second end 3 and the wall 5 of the body 1 has an associated taper. The diameter of the first end 2 may, for example, be 286 mm and the diameter of the second end may be 272 mm. Preferably, the first end 2 is then provided with a flange 6 and a swedge 7 is optionally formed in the wall 5 adjacent the first end 2, as seen in Figure lc, although the swedge and/or flange may of course be formed during the second stage of production such as shown in, for example, Figure 2b. which is described below. The body 1 is then inverted and a flange 8 is formed at the second end 3, shown in Figure Id., to which a cover 9 is subsequently fitted, such as by seaming, as illustrated in Figure le..

The tapered body 1 shown in Figure le. may then be removed from a production line and stacked in a manner shown in Figure If. for storage or transport to a satellite location where a remote production facility completes the second stage of production, shown in Figure 2.

In that regard, the partially constructed drums may be unstacked and presented on a production line as illustrated in Figure 2a.. The drum 1 is inverted at Figure 2b. and transferred to an apparatus 20, described with reference to Figure 3.

The apparatus 20 includes an expansion device 21 with formers 22, having substantially parallel outer surfaces 23, and a central driver 24, which is wedge-shaped for engagement with inwardly tapered walls 25 of formers 22. The formers 22 are shown in a contracted condition in Figure 3b., in which the driver 24 is somewhat axially withdrawn from between the formers. To effect a second deforming process, the device 21 is lowered into the drum 1, shown in Figure 3a., to assume a position illustrated in Figure 3c .

The driver 24 is then axially advanced between the formers 22 to engage the tapered walls 25 and drive the formers 22 radially outwardly. This results in the wall 5 of the drum 1 being engaged, particularly toward the end 3, and correspondingly driven radially outwardly so that the wall 5 conforms to the parallel outer surfaces 23 of the formers 22. The driver is then withdrawn to allow the formers to return to the contracted condition, for subsequent removal of the device from the drum 1.

As such, the body 1 is expanded over a region 10 of the wall 5, as illustrated in Figure 2c, from a location 11 , adjacent the second end 3 toward the first end 2 so as to substantially remove the taper and render sides of the wall substantially parallel. A second swedge 12 may simultaneously or later be formed in the wall 5. A second cover 13 may then be fitted to the first end 2, over flange 6 by seaming or the like as shown in Figure 2d. to provide a finished drum 14. A final step of inverting is performed, as illustrated in Figure 2e., such that the cover 9 forms the top of the drum 14 and the cover 13 forms the bottom 16 thereof.

As may be appreciated from the above, the drum 14 is produced in a two-stage process where the second stage of the process may be effected at a remote satellite location, although a single production line may of course be used for both stages. The tapered form of the drum at the end of the first stage, as illustrated in Figures le. and If. allows for the bodies 1 to be stacked in a compact manner to reduce storage space and lower transport costs, to the remote location. The second stage shown in Figure 2 requires minimal production machinery and may therefore lead to cheaper local assembly of the drum at the satellite location. The structure of the body at the end of the first stage may also be used in constructing a conventional tapered open drum and the parallel sided drum and tapered drum may thereby be formed at least partially on a common production line possibly using metal sheets of the same dimension, thereby reducing overall working capital and tooling required to produce either type of drum since the production processes are no longer mutually exclusive. Another advantage of the invention is that a previous step in the production of a conventional tight head drum is dispensed with, i.e. the step of reducing the diameter of the drum to form the flange at the top of the drum.

The invention has been described by way of non-limiting example only, and many modifications and variations may be made thereto without departing from the spirit and scope of the invention described.

Claims

The Claims:

1. A method of manufacturing a drum including: forming an open ended body; performing a first deforming process on the body to form a taper in a wall of the body such that one end of the body has a larger diameter than a second end thereof; and performing a second deforming process on the body to substantially remove the taper.

2. A method as claimed in claim 1, wherein the first and second deforming processes comprise expansion processes.

3. A method as claimed in claim 1 or 2, wherein a cover is fitted to the second end of the body prior to the second deforming process

4. A method as claimed in claim 3, wherein a flange is applied to the second end prior to fitting the cover.

5. A method as claimed in claim 3 or 4, wherein a swedge is formed in the wall of the body prior to fitting the cover.

6. A method as claimed in any one of the preceding claims, wherein the second deforming process includes expanding the body over a region of the wall extending from a location adjacent the second end toward the first end whereby to render sides of the wall substantially parallel.

7. A method as claimed in claim 6, wherein a second swedge is formed in the wall adjacent the second end.

8. A method as claimed in any one of the preceding claims, wherein a second cover is fitted to the first end such as by seaming.

9. A drum formed in accordance with the method of any one of claims 1 to 8.

10. Apparatus performing a deforming process on a partially formed drum having a tapered wall with an open first end of a diameter larger than a second end, which is fitted with a cover, the apparatus including an expansion device arranged to extend into the body and expand the body to substantially remove the taper and render sides of the wall substantially parallel.