NZ532815A - Improvements in and relating to storage vessels - Google Patents

Abstract

A method for the manufacture of storage vessels including the steps of: fabricating a hollow and substantially enclosed cylindrical shape, having a tubular portion and two ends, from metal; constraining the cylindrical shape about each end only; and applying pressure to the interior of the cylindrical shape, the pressure being sufficient to plastically deform the metal and to permanently change at least the shape of the tubular portion of the cylindrical shape to produce a storage vessel that is substantially barrel shaped.

Description

532815 Patents Form # 5 \ NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL # : 532815 DATED : TITLE: 07 May 2004 Method for the Manufacture of Storage Vessels, and Vessels Manufactured by the Method We, ROBT. STONE & CO. LIMITED Address: Mechanical Engineers & Contractors, 31 Maurice Road, Penrose, Auckland, New Zealand Nationality: A New Zealand company do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: 130849NZ_Cap_200508Q5_1024_JON.doc FEE CODE 1050 Ifti'fcLLbC"!UAL li^V OPPfCE ' i I\'J -5 AUG 2005 Ji§_CE IVED Introduction The present invention relates to a method for the manufacture of storage vessels and to storage vessels manufactured by the method, and in particular, but not exclusively, to a 5 method for the manufacture of barrel shaped storage vessels and to barrels manufactured by the method.

Background Barrel shaped storage vessels have been used for some time. The traditional method of making barrels is from wood, typically for the wine industry. The barrels are made from 10 staves, usually narrow tapered strips of oak, bound together with hoops. However this method of making barrels is a relatively complex, labour intensive, and expensive process. The cooperage industry still exists today, but primarily only because oak barrels are a required by the wine industry.

The shape of a barrel, with its curved sides, is useful because the barrel on its side acts like a 15 single pivot wheel and is easily turned and rolled from one place to another. Also the curved sides are relatively strong or resilient to knocks from the outside.

Because of these advantages, the use of a curved barrel might be more widespread if their manufacturing could be made easier.

During more recent times, drums or other containers made of steel have replaced many the 20 earlier uses for wooden barrels. Stainless steel is used where it is important to maintain product integrity for example when storing products relating to food and drink. Stainless steel containers are now frequently used in the beverage industry, including the wineries and vineyards. Modern winemaking is generally geared toward the use of stainless steel containers.

However, particularly in situations where the containers are used over and over, it is important that these containers can be easily and thoroughly cleaned. Internal sharp corners that are present in many fabricated metal containers can make cleaning difficult. While it is 130849NZ_CS 0805 possible to eliminate such corners using conventional manufacturing processes, the costs to do so can be prohibitive.

Object It is therefore an object of the present invention to provide a method for the manufacture of 5 storage vessels, and storage vessels manufactured by the method, which will at least go some way towards overcoming the above mentioned problems, or which will at least provide the public with a useful choice.

Statements of the Invention Accordingly, in a first aspect, the invention may broadly be said to consist in a method for 10 the manufacture of storage vessels including the following steps; the fabrication of a hollow and substantially enclosed cylindrical shape, having a tubular portion and two ends, from metal, the constraint of the cylindrical shape about each end only, and the application of pressure to the interior of the cylindrical shape, wherein the pressure is sufficient to plastically deform the metal, and to permanently change at least the shape of the tubular portion of the cylindrical shape, to produce a storage vessel that is substantially barrel shaped.

Preferably the constraint of the cylindrical shape about each end is achieved by placing the cylindrical shape within a clamping means, wherein the clamping means is adapted to 20 constrain the movement of each end of the cylinder in at least in a direction away from the centre of the cylinder substantially along the principal axis of the cylinder.

Preferably the cylindrical shape is fabricated by welding the pieces forming the ends to the tubular portion.

While the tubular portion could be manufactured by a number of processes, for example by 25 extrusion, preferably the tubular portion is manufactured by forming sheet metal into a tubular shape and by welding any seams. 130849NZ_CS 0805 Preferably the end pieces are substantially dish shaped, for example ends that are formed from sheet metal that has been pressed into a dish shape or from a disc of sheet metal having knuckled edges.

Preferably the pressure is applied in the form of hydraulic pressure.

While the storage vessel can be made from a range of metals or metal alloys, preferably the storage vessel is made from stainless steel.

Optionally the storage vessel is further modified by an additional step of pressing indentations into the shape, for example, the pressing of a recess into one of both ends of the vessel.

In a second aspect, the invention may broadly be said to consist in a method for the manufacture of a curved sided tube for a storage vessels including the following steps; the fabrication of a tubular shape, from metal, the constraint and sealing of the tubular shape at each end only, and the application of pressure to the interior of the tubular shape, wherein the pressure is sufficient to plastically deform the metal, and to permanently change at least the shape of the tubular shape, to produce a curved sided tube.

Preferably the method further includes the fitting of ends to the curved sided tube to form a storage vessel.

In a third aspect, the invention may broadly be said to consist in a storage vessel 20 manufactured using a method for the manufacture of storage vessels substantially as specified herein.

Preferably the storage vessel is a barrel.

In a further aspect the invention may broadly be said to comprise a method of forming a hollow metallic body comprising the following steps: 130849NZ_CS 0805 placing a deformable body within the confines of a plurality of constraints, the constraints being adapted to restrain deformation of one or more surfaces of the body; introducing a fluid into the deformable body to deform the body, the arrangement of the deformable body and the constraints being such that deformation of the body is 5 able to occur over at least an unrestrained surface of the body.

Preferably, the deformable body is comprised of one or more sections of sheet metal with contiguous sections bonded together.

Preferably the said bonding is achieved by welding.

Preferably the sections are comprised of stainless steel sheet metal.

Preferably, the constraining means can be selected from the group comprising a hydraulic press, a multiple tie rod clamp or heavy end-plate clamps.

Preferably the pressurising fluid of is a substantially non-compressible fluid such as water or oil.

Optionally, the said method is further modified by at least one additional step, such as the 15 recessing of the exterior surface of the body.

Optionally, the deformable body is comprised of three-sections in the form of a closed-ended tube, which after deformation results in a closed-ended curved barrel.

Preferably the three sections are made of sheet metal, wherein one is a rectangular section rolled and welded to form a tube and the other two are shaped knuckled disc sections that 20 form end fittings and are welded to the tube.

Optionally the two sections making up the end fittings of the tube are flat circular discs.

Optionally, the deformable body is a tube, that is a straight-sided cylinder, of any length and/or diameter, constrained and sealed by the clamping means about its two circular ends which under deforms under hydrostatic pressure to an open-ended barrel-shaped cylinder. In 25 this embodiment it is important to recognise that the open ends of the tube must be clamped and sealed by the clamping means. In this case the pressurising fluid can be introduced through the side of the hollow body or through the clamping means, 130849NZ CS 0805 Optionally, the method includes a further step comprising the pressing of indentations into the said barrel, for example pressing a recess into one end or both ends of the barrel.

Optionally the deformable body is provided with or is adapted to receive a plastics material adapted to form a liner for the finished hollow body.

In yet a further aspect the invention may broadly be said to consist in a hollow metallic body manufactured using a method for the manufacture of storage vessels substantially as specified herein.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or 10 all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Brief Description of the Drawings A preferred embodiment of the invention will now be described with reference to the accompanying drawings in which like numerals designate the same corresponding parts throughout the several figures, and; Figure 1 is an exploded side view showing a preferred method of assembly of a storage vessel, Figure 2 is a side view of the storage vessel complete with a hydraulic filling nozzle, Figure 3 is a side view showing the storage vessel within a first example of a clamping device, Figure 4 is a side view showing the storage vessel within a second example of a clamping device, Figure 5 is a side view of the storage vessel when pressure is applied, Figures 6 and 6a are side views showing an optional indentation process, and 130849NZ_CS 0805 Figure 7 is a side view showing a formed storage vessel complete with an internal liner.

With reference to Figures 1 to 5 a process for the manufacture of a storage vessel (10) is explained in detail. Beginning with Figure 1, the storage vessel (10) can be initially 5 constructed by joining two end pieces (11) to a tubular portion (12). The storage vessel (10) is shown in an exploded view in this figure.

The tubular portion (12) can be constructed from stainless steel sheet which is rolled into a tubular shape and is then welded along a longitudinal weld seam (13), to form a tube. However, clearly the tubular portion (12) can be formed by a number of alternative methods, 10 for example, from spiral welded tube, or from extruded tube, etc.

The end pieces (11) of the preferred embodiment shown are not flat, but are dish shaped, that is substantially flat but having a curved lip or rim about their circumference. The dish shape can be formed by a number means, for example, by pressing, or by knuckling. In the example shown the end pieces (11) are each knuckled discs.

Figure 2 shows the two end pieces (11) welded to the tubular portion (12) along two circular weld seams (21) to form the hollow and substantially enclosed storage vessel (10) which at this stage has the appearance of a straight-sided drum. A fitting (22) can be welded about a hole drilled in the storage vessel (10), to allow pressure to be applied to the interior of the vessel (10) later in the manufacturing process.

Figures 3 and 4 show two alternative methods of constraining the ends of the storage vessel (10). In figure 3 the storage vessel (10) is shown clamped between two heavy end plates (31) which are connected by a number of tie rods (32). The tie rods (32) can for example have threaded ends, and by tightening a series of nuts (33) the heavy end plates (31) can be brought into contact with the flat surfaces of the ends (11) of the storage vessel (10).

Figure 4 shows an alternative method of constraining the ends (11) of the storage vessel (10) using a hydraulic press (40) which includes a hydraulic ram (41) which can exert a force towards an opposing fixed buttress (42). Both the ram and the fixed buttress (42) are provided with heavy plates (43) which are adapted to engage with the flat surfaces of the 130849NZ CS 0805 ends (11) of the storage vessel (10). The storage vessel (10) can be constrained between the two heavy plates (43).

With reference to Figure 5 the deformation of the storage vessel (10) to form a barrel shape is explained. In figure 5 only the heavy plates (31) or (43) of the constraints, explained with 5 reference to figures 3 and 4 above, are shown for clarity.

A pressurising fluid 51, for example oil or water, can be introduced into the storage vessel (10) via a hose (52), which is connected to the fitting (22). Preferably all air is removed from the storage vessel (10) at this time. With the storage vessel (10) held between the heavy plates (31) or (43), and with the ends (11) constrained at least in the direction along principal axis of the substantially cylindrically shaped storage vessel (10), by the heavy plates (31) or (43), the tubular portion (12) of the can be deformed from the inside using hydraulic pressure.

If sufficient pressure is applied, via the hose (52), the metal of the tubular portion (12) will deform at first elastically, and as more pressure is applied, plastic deformation will begin to 15 occur. As a consequence of the deformation caused by the internal hydraulic pressure, the storage vessel (10) will naturally take on the form of a curved sided barrel.

Particular care is needed in the configuration and placement of the clamps so that the desired deformation can take place. The portions of the storage vessel (10) that are constrained will have limited deformation, while the areas of the storage vessel (10) that are free to move will 20 experience the greatest deformation.

While deformation of the ends (11) is prevented in the main, by the constrained heavy plates (31) or (43), some deformation may occur, particularly in the areas where the ends (11) are welded to the tubular portion (12). Particularly if the ends (11) are dish shaped, as the curved lip of the dish shape will tend to deform in sympathy with the ends of the tubular 25 portion (12) to which they are welded.

The method described above is a new adaptation of the hydro-forming process which has been used for a number of years. In this method, the particular hydro-forming parameters, such as internal pressure and external forces, need to be applied in a relatively precise 130849NZ CS 0805 manner to ensure that the desired final profile is achieved. In this method some surfaces are constrained to prevent or limit deformation while others are able to deform as required.

With reference to Figures 6 and 6a an optional further step of deforming at least one end (11) of the vessel (10) is shown. In this case a hydraulic press (61) is used to press a tool 5 (62) into the end (11) to produce an indentation (63), in this case a "kettle bottom" indentation. Clearly this step could alternatively be carried out when the ends (11) are initially formed, but the heavy plates (31) or (43) would need to be shaped accordingly to prevent deformation of the indentation (63) during the hydro-forming process. The indentation (63) can be advantageous in that the ends (11) are then provided with a rim 10 which can make the vessels (10) easier to stack.

Figure 7 shows a side view of a formed storage vessel (10) with a liner (71) sited on the interior surface of the vessel (10) for the purpose of protecting the contents from contamination or the vessel (10) from corrosive materials that the vessel (10) may contain. The liner (71) can for example be a liner made from a suitable plastics material.

Variations In a variation to the method described above the tubular portion (12) can be suitably deformed into a curved sided barrel shape, prior to any ends being fitted. In this case the constraining means would both clamp and seal of the ends of the tubular portion (12). Again, internal pressure could be applied to the interior of the tubular portion (12) to produce 20 the desired curved barrel shape. The ends (11) could be added later to form an enclosed barrel.

While the above example has been described with reference to a storage vessel (10) made of stainless steel, it will be understood that any metal or metal alloy could also be used in its construction.

Finally it will be appreciated that various other alterations and modifications may be made to the foregoing without departing from the scope of the invention. 130849NZ CS 0805 Advantages The advantage of the method described above is that a relatively complex barrel shape can be formed out of metal, using a relatively simple method, and without the need for relatively complex and expensive tools.

Jipers Attorneys for 10 Robt. Stone & Co. Limited INTELLECTUAL PROPERTY OFFICE or v 7 - 5 ;VJS 2005 JI&CEIV £ D 130849NZ_CS 0805

Claims (12)

"intellectual PROPfcHIV UI-HLL OF N.Z. 1 8 AUG 2005 -11 - received We claim;

1. A method for the manufacture of storage vessels including the following steps; the fabrication of a hollow and substantially enclosed cylindrical shape, having a tubular portion and two ends, from metal, 5 the constraint of the cylindrical shape about each end only, and the application of pressure to the interior of the cylindrical shape, wherein the pressure is sufficient to plastically deform the metal, and to permanently change at least the shape of the tubular portion of the cylindrical shape, to produce a storage vessel that is substantially barrel shaped. 10

2. A method for the manufacture of storage vessels as claimed in claim 1, wherein the constraint of the cylindrical shape about each end is achieved by placing the cylindrical shape within a clamping means and wherein the clamping means is adapted to constrain the movement of each end of the cylinder in at least in a direction away from the centre of the cylinder substantially along the principal axis of 15 the cylinder.

3. A method for the manufacture of storage vessels as claimed in any preceding claim, wherein the cylindrical shape is fabricated by welding the pieces forming the ends to the tubular portion.

4. A method for the manufacture of storage vessels as claimed in any preceding claim, 20 wherein the tubular portion is manufactured by forming sheet metal into a tubular shape and by welding any seams.

5. A method for the manufacture of storage vessels as claimed in any preceding claim, wherein the end pieces are substantially dish shaped.

6. A method for the manufacture of storage vessels as claimed in any preceding claim, 25 wherein the pressure is applied in the form of hydraulic pressure.

7. A method for the manufacture of storage vessels as claimed in any preceding claim, wherein the storage vessel is made from stainless steel. 130849NZ_CS.0805.doc - 12-

8. A method for the manufacture of storage vessels as claimed in any preceding claim, wherein the storage vessel is further modified by an additional step of pressing indentations into the shape, for example, the pressing of a recess into one of both ends of the vessel.

9. A method for the manufacture of storage vessels substantially as specified herein with reference to any of the accompanying drawings.

10. A method for the manufacture of a curved sided storage vessel including the following steps; the fabrication of a tubular shape, from metal, the fitting of ends to the tubular shape to form a storage vessel, the constraint of the storage vessel about each end only, and the application of pressure to the interior of the storage vessel, wherein the pressure is sufficient to plastically deform the metal, and to permanently change at least the shape of the tubular shape, to produce a curved sided storage vessel.

11. A storage vessel manufactured using a method for the manufacture of storage vessels, or a method for the manufacture of a curved sided storage vessel, substantially as claimed herein.

12. A storage vessel as claimed in claim 11, wherein the storage vessel is a barrel. END OF CLAIMS INTELLECTUAL PROPERTY OFFICE OF N.Z. 15 NOV 2005 RECBIVID 130849NZ_R'vsdClms. 1105.doc