GB2121332A

GB2121332A - Sealing of drums

Info

Publication number: GB2121332A
Application number: GB08228161A
Authority: GB
Inventors: Michael Britton
Original assignee: PLASTIC DRUM Co Ltd
Current assignee: PLASTIC DRUM Co Ltd
Priority date: 1982-05-27
Filing date: 1982-10-01
Publication date: 1983-12-21
Also published as: GB2121332B

Abstract

A method of seaming end closures onto drums comprises a first step of engaging flanges 17, 16 of the drum and end closure respectively in a forming groove of a first curl roller (9, 29) and moving the roll towards the drum as the drum is rotated to thereby effect initial bending over and a second step of engaging a second curl roller 18 into engagement with the partially rolled flanges after at least partial retraction of the first curl roller (9, 29) and similarly moving the second curl roller towards the drum whilst pressing downwardly with a tapered control roll 21 or an inclined face (32) of a flange (31) of the first curl roll (29) on the rolled up flanges. A tight multi-layered rolled seam can be formed in this way, the sealing being completed for example by precoating the flanges with mastic before engaging them with the curl rolls. <IMAGE>

Description

SPECIFICATION Sealing of drums This invention relates to an apparatus and method for effecting end seals of circular metal containers such as drums.

Sealing of end closures to the cylindrical body of a drum is carried out by overlapping flanges of the end closure and drum body to produce a coiled cross-sectioned bead around the rim. This can be done by means of curl rollers which have specially shaped peripheral forming grooves into which the flanges extend, and the curl rollers are moved towards the axis of the drum as the drum is rotated, thereby rolling over the flanges to form a seal. One method using two curl rollers successively in a two stage process is described in British Patent Specification 1534084 (Gallay), each roller having a different shaped groove, the first for providing a curled over edge on the end closure flange, and the second for completing the rolling of the bead.

In accordance with the invention there is provided a method of joining a multi-layer seam between a cylindrical body and an end closure, wherein the cylindrical body and the end closure each have a flange, one of which flanges extends outwards beyond the other, the said other flange being inclined at a predetermined angle to the said one flange, comprising engaging said flanges with a first curl roller having a peripheral forming groove therein is engaged with the flanges and moved towards the drum as the drum is rotated whereby the flanges are rolled up together.

The first roll is preferably then retraced and whilst the drum is still rotating the second curl roller moves in to engage the pre-curled flanges to complete the curling cycle. A control roller may be provided to bear on the outside edge of the flanges throughout the second curling operation to ensure, uniform growth of the seam in the curl roller. Alternatively, a modified form of first curl roller with an inclined flange face may be used for this purpose.

The seam is thereby kept as tight as possible, with the initial curl as small as possible, and jamming is substantially eliminated. The method can be used to produce seams of multiple thicknesses of metal, of up to 9 thicknesses.

The flanges may be coated with mastic prior to forming the seam so that the sealing of the seam is completed against the possibility of capilliary leakage between the metal layers.

A preferred method, and embodiment of apparatus according to the invention will now be described by way of example only, with reference to the accompanying drawing wherein:~ Fig. 1 is a sectional view of a part of the apparatus at an initial stage in the process: Fig. 2, is a similar view of a successive stage of the process: Fig. 3 is a similar view of the next stage of the process. using an additional roller, Fig. 4 is a similar view of the apparatus at the completion of the process.

Fig. 5 is a diagrammatic cross-section of the periphery of a modified curl roll which eliminates an extra roller, and Fig. 6 shows a view corresponding to Fig. 3 using the modified curl roll.

As illustrated in Fig. 1 a chuck 10 grips on a drum end closure 12 by pressing axially against the drum thus locking the taper 8 of the chuck 10 with the corresponding taper of the drum end closure 12. The end closure 12 has a flange 16 which extends horizontally whilst a drum shell 14 has a flange 17 inclined to the flange 16 at an angle between 00--160 advantageously 150. A first stage curl roll 9 rotatable on an axis parallel to the drum body is moved towards the chuck 10.

Curl roll 9 rotates by frictional contact with the flange 16 and spins in the end closure flange 16 to give a tight curl 8 as in Fig. 2.

First stage curl roll 9 is retracted and the second stage curl roll 18 approaches chuck 10 in a similar fashion to the first stage curl roll 9 Fig. 2.

A seam between flanges 16 and 17 is formed by rolling the metal into a multiturned coil accomplished by forcing curl roll 1 8 towards chuck 10 the control roller 21 is angled so that it bears on the outside of flange 1 6 throughout the second seaming operation thus ensuring correct growth of the seam in the form of curl roll 18 ending up as Fig. 4.

A modified first curl roll 29 is shown in partial cross-section in Fig. 5. Instead of a semicircular cross-sectioned groove with a horizontal overhanging flange face, the groove 30 has associated an overhanging flange 31 with an inclined face 32. Fig. 6 shows this modified first stage roll 29 in use in association with a second stage curl roll 18 similar to that of Figs. 3-4. The roll 29 is held in the position shown as the curl roll 18 is moved towards the chuck 10 with the inclined face 32 bearing down on the growing rolled up seam, so that the face 32 fulfills the function of the control roller 21 (Fig. 3).

The inclination of the flanges 16 and 17 one to the other ensures that when relative "creep" of the flanges occurs thus does not involve large frictional forces over large planar areas (the drawings of the Gal lay British Patent 1 534-84 clearly show that such "creep" occurs) and thus eliminates a potential source of jamming with possible damage to the structure and impermeability of the seam formed.

Before commencing the seaming operation, the flanges 16 and 17 may be coated with mastic to fill any spaces or gaps occurring in the seam structure. The method and apparatus described can be used for creating rolled up seams of double coiled cross-section involving multiple thicknesses of metal, of up to 9.

Claims

1. A method of forming a multi-layer seam between a cylindrical body and an end closure, wherein the cylindrical body and the end closure each have a flange, one of which flanges extends outwards beyond the other, the said other flange

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

Claims

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

SPECIFICATION Sealing of drums This invention relates to an apparatus and method for effecting end seals of circular metal containers such as drums.

Sealing of end closures to the cylindrical body of a drum is carried out by overlapping flanges of the end closure and drum body to produce a coiled cross-sectioned bead around the rim. This can be done by means of curl rollers which have specially shaped peripheral forming grooves into which the flanges extend, and the curl rollers are moved towards the axis of the drum as the drum is rotated, thereby rolling over the flanges to form a seal. One method using two curl rollers successively in a two stage process is described in British Patent Specification 1534084 (Gallay), each roller having a different shaped groove, the first for providing a curled over edge on the end closure flange, and the second for completing the rolling of the bead.

In accordance with the invention there is provided a method of joining a multi-layer seam between a cylindrical body and an end closure, wherein the cylindrical body and the end closure each have a flange, one of which flanges extends outwards beyond the other, the said other flange being inclined at a predetermined angle to the said one flange, comprising engaging said flanges with a first curl roller having a peripheral forming groove therein is engaged with the flanges and moved towards the drum as the drum is rotated whereby the flanges are rolled up together.

The first roll is preferably then retraced and whilst the drum is still rotating the second curl roller moves in to engage the pre-curled flanges to complete the curling cycle. A control roller may be provided to bear on the outside edge of the flanges throughout the second curling operation to ensure, uniform growth of the seam in the curl roller. Alternatively, a modified form of first curl roller with an inclined flange face may be used for this purpose.

The seam is thereby kept as tight as possible, with the initial curl as small as possible, and jamming is substantially eliminated. The method can be used to produce seams of multiple thicknesses of metal, of up to 9 thicknesses.

The flanges may be coated with mastic prior to forming the seam so that the sealing of the seam is completed against the possibility of capilliary leakage between the metal layers.

A preferred method, and embodiment of apparatus according to the invention will now be described by way of example only, with reference to the accompanying drawing wherein:~ Fig. 1 is a sectional view of a part of the apparatus at an initial stage in the process: Fig. 2, is a similar view of a successive stage of the process: Fig. 3 is a similar view of the next stage of the process. using an additional roller, Fig. 4 is a similar view of the apparatus at the completion of the process.

Fig. 5 is a diagrammatic cross-section of the periphery of a modified curl roll which eliminates an extra roller, and Fig. 6 shows a view corresponding to Fig. 3 using the modified curl roll.

As illustrated in Fig. 1 a chuck 10 grips on a drum end closure 12 by pressing axially against the drum thus locking the taper 8 of the chuck 10 with the corresponding taper of the drum end closure 12. The end closure 12 has a flange 16 which extends horizontally whilst a drum shell 14 has a flange 17 inclined to the flange 16 at an angle between 00--160 advantageously 150. A first stage curl roll 9 rotatable on an axis parallel to the drum body is moved towards the chuck 10.

Curl roll 9 rotates by frictional contact with the flange 16 and spins in the end closure flange 16 to give a tight curl 8 as in Fig. 2.

First stage curl roll 9 is retracted and the second stage curl roll 18 approaches chuck 10 in a similar fashion to the first stage curl roll 9 Fig. 2.

A seam between flanges 16 and 17 is formed by rolling the metal into a multiturned coil accomplished by forcing curl roll 1 8 towards chuck 10 the control roller 21 is angled so that it bears on the outside of flange 1 6 throughout the second seaming operation thus ensuring correct growth of the seam in the form of curl roll 18 ending up as Fig. 4.

A modified first curl roll 29 is shown in partial cross-section in Fig. 5. Instead of a semicircular cross-sectioned groove with a horizontal overhanging flange face, the groove 30 has associated an overhanging flange 31 with an inclined face 32. Fig. 6 shows this modified first stage roll 29 in use in association with a second stage curl roll 18 similar to that of Figs. 3-4. The roll 29 is held in the position shown as the curl roll 18 is moved towards the chuck 10 with the inclined face 32 bearing down on the growing rolled up seam, so that the face 32 fulfills the function of the control roller 21 (Fig. 3).

The inclination of the flanges 16 and 17 one to the other ensures that when relative "creep" of the flanges occurs thus does not involve large frictional forces over large planar areas (the drawings of the Gal lay British Patent 1 534-84 clearly show that such "creep" occurs) and thus eliminates a potential source of jamming with possible damage to the structure and impermeability of the seam formed.

Before commencing the seaming operation, the flanges 16 and 17 may be coated with mastic to fill any spaces or gaps occurring in the seam structure. The method and apparatus described can be used for creating rolled up seams of double coiled cross-section involving multiple thicknesses of metal, of up to 9.

Claims

1. A method of forming a multi-layer seam between a cylindrical body and an end closure, wherein the cylindrical body and the end closure each have a flange, one of which flanges extends outwards beyond the other, the said other flange being inclined at a predetermined angle to the said one flange, comprising engaging said flanges with a first curl roller having a peripheral forming groove therein and moving said first curl roller towards the drum as the drum is rotated whereby the flanges are rolled up together.

2. A method according to claim 1 comprising the further step, whilst continuing to rotate the drum of engaging the precurled flanges by means of a second curl roller which is in turn moved towards the drum to complete the rolling up of the flanges.

3. A method according to claim 2 wherein during said further step a pressure exerting means is provided to bear on the outside edge of the flanges.

4. A method according to claim 3 wherein said pressure exerting means comprises a control roller having a horizontal axis directed towards the drum and a tapered surface narrowing towards the drum.

5. A method according to claim 3 wherein the pressure exerting means comprises an inclined lower surface on a flange formed on the first curl roll above the forming groove, the first curl roll being only partially withdrawn at the conclusion of the first step.

6. A method according to any of claims 2 to 5 wherein the forming groove of the second curl roller is larger than that of the first curl roller.

7. A method of forming a multi-layer seam substantially as hereinbefore described with reference to and as illustrated in Figs. 1 and 2, with Figs. 3 and 4 or Figs. 5 and 6 of the accompanying drawings.

8. A drum having an end closure sealed thereto by a method according to any one of claims 1 to 7.

New claims or amendments to claims filed on 1 st Aug '83 Superseded claims 1, 2 and 3 Claims 4 to 8 renumbered and appendacies corrected New or amended claims:~

1. A method of forming a multi-layer seam between a cylindrical body and an end closure, wherein the cylindrical body and the end closure each have a flange, one of which flanges extends outwards beyond the other, the said other flange being inclined at a predetermined angle to the said one flange, which method comprises engaging said flanges with a first curl roller having a peripheral forming groove therein, moving said first curl roller towards the drum while rotating the drum whereby the flanges are curled together engaging the pre-curled flanges with a second curl roller and moving said second curl roller towards the drum while rotating the drum whereby rolling up of the flanges together is completed, pressure exerting means having an inclined surface being provided to bear on the outside edge of the flanges during the engagement of the second curl roller.