A PUNCH, A SEMI-FINISHED CAN, AND A CAN MANUFACTURED WITH USE OF THE SAID PUNCH

Abstract

A punch for drawing beverage cans comprising a cylindrical body with a separated region (1) forming a can side wall having diameter D1, a step (2), and a region (3) forming a thick wall, characterized in that, the region (3) forming thick wall starts from the step (2), and the diameter D2 of the punch in this region (3) is variable and is smaller than the diameter D1 of the region (1) forming can's sidewall. The object of the invention is also a beverage can in the form of a semi-finished can, and a finished beverage can manufactured with use of the said punch.

Claims

1. A punch for drawing beverage metal cans comprising a cylindrical body with a separated region (1) forming a can side wall having diameter D1, a step (2), and a region (3) forming a thick wall starts from the step (2), and the diameter D2 of the punch in this region (3) is variable and is smaller than the diameter D1 of the region (1) forming can's sidewall, characterized in that the region (3) forming a thick wall of the can has length smaller than 100 mm, the diameter D2 of the punch in the region forming the can sidewall is in the range from 30 to 100 mm, the step has length (L2) from 0.1 to 40 mm, height from 1 to 500 mm, and an angle in relation to the axis of the punch from 1 to 80 degrees.

2. The punch according to claim 1, characterized in that, the region (3) forming a thick wall of the can comprises two forming sections (5, 7), where the first section (5) has length (L5) from 0.01 to 40 mm, and the second section 7 has length (L7) from 0.1 to 30 mm.

3. The punch according to claim 1, characterized in that, the region (3) forming a thick wall of the can comprises three forming sections (4, 5, 7), where the first section (4) has length (L4) from 0.05 to 40 mm, the second section (5) has length (L5) from 0.01 to 40 mm, and the third section 7 has length (L7) from 0.1 to 30 mm.

4. The punch according to claim 1, characterized in that, the region (3) forming a thick wall of the can comprises three forming sections (5,6,7), where the first section (5) has length (L5) from 0.01 to 40 mm, the second section (6) has length (L6) from 0.1 to 30 mm, and the third section (7) has length (L7) from 0.1 to 30 mm.

5. The punch according to claim 1, characterized in that, the region (3) forming the thick wall of the can comprises four forming sections (4, 5, 6, 7), where the first section the first section (4) has length (L4) from 0.05 to 40 mm, the second section (5) has length (L5) from 0.01 to 40 mm, the third section (6) has length (L6) from 0.1 to 30 mm, and the fourth section (7) has length (7) from 0.1. to 30 mm.

6. The punch according to, claim 1, characterized in that, the diameter D2 of the punch in the region forming the thick wall of the can is smaller than the diameter D1 of the punch in the region forming the can body by at least 10 mm.

7. The punch according to claim 1, characterized in that, the diameter D2 of the punch in the region forming the thick wall of the can varies linearly or/and non-linearly.

8. A beverage metal can in the form of a semi-finished can intended for the operation of necing, characterized in that, it has a thick wall (8) of variable thickness t22, t23 ranging from 80 to 220 mm.

9. The can according to claim 11, characterized in that, the thickness of the semi-finished can at t24 is within the range from 80 to 200 mm.

10. The can according to claim 11, characterized in that, the thickness t22 is smaller than t23, the thickness t22 and t23 is smaller than t21, the thickness t24 is smaller than t21.

11. A finished beverage can, characterized in that, it has a neck (9) having wall thickness t4, t42 and t43 comprising in the range from 80 to 220 mm.

12. The finished beverage can according to claim 14, characterized in that, the wall thickness t41=t42=t43.

13. The finished beverage can according to claim 14, characterized in that, t43 is greater than t41.

14-16. (canceled)

Description

EXAMPLES

[0028] The subject of the invention is disclosed at the drawings, where FIG. 1 shows a punch known from the prior art, FIG. 2its cross-section, FIG. 3 shows a punch according to the invention, FIG. 4-7 show a cross-sections of different variants of punches, FIG. 8 show a can in the form of a semi-finished can, FIG. 9 shows a cross-section of a thick wall known from the prior art, FIG. 10 shows a cross-section of a thick wall according to the invention, FIG. 11 shows a finished can, FIG. 12 shows a cross-section of can's neck known from the prior art, FIG. 13 shows a cross-section of can's neck according to the invention.

Example 1

Comparative Example

[0029] A punch known from the prior art has a cylindrical body 1 with a step 2 and a region forming a thick wall 3. The region 3 forming a thick wall in the standard solution is characterized by a constant diameter of the punch in the whole lengths L3 forming the profile. The profile of the section forming thick wall is defined by a straight line parallel to the axis of the punch. The step may have height from 0.1 to 200 ?m, and length from 0.01 to 30 millimeters. The length of the L3, defining the thick wall, may vary from 1 to 100 millimeters.

[0030] The wall of the semi-finished can for the manufacture of the can after using the known punch in the upper area is thicker than the middle part (thick wall). This is to enable the operation of forming the neck and to ensure the appropriate thickness of the can flange for connection with the lid and making the so-called double seam. The middle part of the can has a wall thickness of 85-100 ?m, and the upper in the range 100-250 ?m. The thicknesses t11, t12 and t13 are equal to each other. Minimal differences are the result of the quality and tolerance of the tools. The ratio between the thickness t11 and t14 ranges from 0.3 to 0.9. The operation of necking the can causes inhomogeneous thickening of the material in the neck area 9. Depending on the thickness of the (input) raw aluminum sheet thickness, the wall thickness of the finished can neck t31 may range from 100 to 300 ?m, while t32 and t33 from 120-350 ?m. The thickness t35 remains unchanged in relation to the thickness t14 before the necking operation. The number of necking steps varies depending on the can design i.e. height, diameter, seaming diameter, neck shape and the necking device used. A description of the can neck necking process is given in, for example, U.S. Pat. Nos. 5,724,848A, 4,774,839A and 5,297,414A.

Example 2 (FIG. 4)

[0031] A punch comprises a cylindrical body, where the region forming can sidewall 1 has length 140.5 mm and diameter D1 equal to 60 mm. The step 2 has length 20 mm and height of 100 ?m. The region 3 forming thick wall has length 28 mm, and has variable diameter D2. The region 3 forming thick wall consists of four sections. The first section 4 is parallel to the punch axis. The punch diameter D2 in this section is 59.9 mm. The length L4 is 2 mm. The second section 5 ma has length L5 equal to 10 mm. The diameter of the section 5 D2 increases linearly from 59.9 to 59.95 mm. The section 6 has length of L6 2 mm, and its diameter D2 decreases linearly from 59.95 to 59.9. The section 7 has length 14 mm and is parallel to the punch axis. The diameter D2 of the punch in this region is 59.9 mm.

Example 3 (FIG. 5)

[0032] A punch comprises a cylindrical body, where the region forming can body has length 140 mm and diameter D1 equal to 60 mm. The step 2 has length 20 mm and height 30 ?m. The region 3 forming thick wall has length 30 mm, and has variable punch diameter D2. The region 3 forming thick wall consists of three sections. The first section 5 has length L5 equal to 10 mm. The punch diameter D2 in the section 5 varies linearly from 59.97 to 59.986 mm. The second section 6 has length L6 of 2 mm, and the punch diameter D2 decreases linearly from 59.986 to 59.97. The section 7 has length 20 mm and is parallel to the punch axis. The diameter D2 of the punch in this region is 59.97 mm.

Example 4 (FIG. 6)

[0033] A punch comprises a cylindrical body, where the region forming can body 1 has length 140 mm and diameter D1 equal to 60 mm. The step 2 has length 20 mm and height 30 ?m. The region 3 forming thick wall has length 30 mm, and has variable punch diameter D2. The region 3 forming thick wall consists of two sections. The first section 5 has length L5 equal to 11 mm. The punch diameter D2 in the section 5 varies linearly from 59.97 to 59.986 mm. The second section 6 has length L6 of 2 mm, and the punch diameter D2 decreases linearly from 59.986 to 59.97. The section 7 has length 20 mm and is parallel to the punch axis. The diameter D2 of the punch in this region is 59.97 mm.

Example 5 (FIG. 7)

[0034] A punch comprises a cylindrical body, where the region forming can body 1 has length 140 mm and diameter D1 equal to 60 mm. The step 2 has length 20 mm and height of 30 ?m. The region 3 forming thick wall has length 30 mm, and has variable diameter D2. The region 3 forming thick wall consists of four sections. The first section 4 is parallel to the punch axis. The punch diameter D2 in this section is 59.97 mm. The length L4 is 100 ?m. The second section 5 ma has length L5 equal to 10 mm. The diameter D2 of the section 5 varies linearly from 59.97 to 59.986 mm. The section 6 has length of L6 2.5 mm, and its diameter D2 varies linearly from 59.986 to 59.97. The section 7 has length 25 mm and is parallel to the punch axis. The diameter D2 of the punch in this region is 59.97 mm.

Example 6

[0035] A beverage can in the form of a semi-finished can for manufacturing a finished can of thick wall of variable thickness t24 equal to 80 ?m, t23 equal to 170 ?m, t22 equal to 30 ?m and t21 equal to 180 ?m.

Example 7

[0036] A beverage can in the form of a semi-finished can for manufacturing a finished can of thick wall of variable thickness t24 equal to 78 ?m, t23 equal to 150 ?m, t22 equal to 120 ?m and t21 equal to 170 ?m.

Example 8

[0037] A beverage can in the form of a semi-finished can for manufacturing a finished can of thick wall of variable thickness t24 equal to 90 ?m, t23 equal to 180 ?m, t22 equal to 135 ?m and t21 equal to 190 ?m.

Example 9

[0038] A beverage can in the form of a semi-finished can for manufacturing a finished can of thick wall of variable thickness t24 equal to 60 ?m, t23 equal to 150 ?m, t22 equal to 110 ?m and t21 equal to 160 ?m.

Example 10

[0039] A finished beverage can having a neck of a variable wall thickness, where the thickness t45 is equal to 80 ?m, the thickness t41 is equal to 140 ?m, the thickness t42 equal to 142 ?m, the thickness t43 is equal to 146 ?m, and the thickness t44 is equal to 170 ?m.

Example 11

[0040] A finished beverage can having a neck of a variable wall thickness, where the thickness t45 is equal to 60 ?m, the thickness t41 is equal to 120 ?m, the thickness t42 equal to 122 ?m, the thickness t43 is equal to 126 ?m, and the thickness t44 is equal to 160 ?m.

Example 12

[0041] A finished beverage can having a neck of a variable wall thickness, where the thickness t45 is equal to 65 ?m, the thickness t41 is equal to 135 ?m, the thickness t42 equal to 135 ?m, the thickness t43 is equal to 140 ?m, and the thickness t44 is equal to 160 ?m.

Example 13

[0042] A finished beverage can having a neck of a variable wall thickness, where the thickness t45 is equal to 85 ?m, the thickness t41 is equal to 140 ?m, the thickness t42 equal to 135 ?m, the thickness t43 is equal to 135 ?m, and the thickness t44 is equal to 162 ?m.

Example 14

[0043] A finished beverage can having a neck of a variable wall thickness, where the thickness t45 is equal to 65 ?m, the thickness t41 is equal to 135 ?m, the thickness t42 equal to 135 ?m, the thickness t43 is equal to 135 ?m, and the thickness t44 is equal to 160 ?m.