Pressure resistant basic shell, easy open end and can with easy open end

This invention relates to a basic shell, easy open end and can, especially a pressure resistant basic shell, easy open end and can with easy open end.

The easy open end was invented in last century 60's, and it was widely used in supporting packages for beverage cans and beer cans. Due to its advantages of light weight, small size and repeated use of waste, the easy open end was widely promoted worldwide and the huge production scale was formed. With the increasing demand for easy open ends, the easy open end industry was developed rapidly and the competition became more and more severe. Therefore, in order to save the resources, reduce the cost and meet the needs of market competition, the research and development of pressure resistant easy open end saving materials is not only the demand of enterprise survival and development, but also the certainty of market economic development.

In the prior art, a typical structure is shown in the prior art CN106672390A previously filed by the applicant of the present application. The easy open end structure disclosed in this patent is: it consists of the body and pull ring riveted to the body; the body consists of a can seaming portion, a countersink portion, a ferrule arc portion, an upward extension portion of ferrule and a center panel from periphery to center in the cross section, and the countersink portion and the extension portion forms a circular recess; the countersink is directly connected by the first straight portion, fourth arc portion and fifth arc portion and the end of fifth arc portion is directly connected with the end of ferrule arc section in an externally tangent way; and the upward extension portion of ferrule consists of the second straight portion and seventh arc section and the seventh arc section is connected with the center panel in a tangent way. The patented solution has good pressure resistance performance under the premise of saving materials, but the following deficiencies are still found in actual production:

I. As the countersink portion is only connected by the first straight portion, fourth arc portion and fifth arc portion and the fourth arc portion and fifth arc portion are connected in an externally tangent way, when the test pressure reaches the limit value during a pressure test, more than 80% of the countersink portion of body may be cracked and the use safety is poor, that is, the fifth arc portion of body will be broken when the pressure exceeds the limit in the actual use and the liquid in the can will be splashed;

II. As the connection of countersink portion and ferrule arc section is the externally tangent connection of arc to arc, the contact area of basic shell and can seaming mould (commonly known as seaming head) is too small and it's only the line contact, which results in the instability of can seaming and could not ensure the quality of can seaming.

The purpose of present invention is to provide a pressure resistant basic shell, easy open end and can with easy open end to lower the probability of breakage due to the failure of pressure resistance and improve the use safety and stability of can seaming under the premise of unchanged material thickness and pressure resistance value.

In order to achieve the purpose, the technical solution of basic shell applied by the present invention is: a pressure resistant basic shell consists of a can seaming portion, a countersink portion, a ferrule arc portion, an upward extension portion of ferrule and a center panel from periphery to center in the cross section; the countersink portion consists of the first straight portion, fourth arc portion and fifth arc portion, and the first end of first straight portion is connected with the corresponding end of seaming portion, and its second end is connected with the first end of fourth arc portion and the first straight portion is connected with the fourth arc portion in a tangent way; the second end of fourth arc portion is connected with the first end of fifth arc portion and the fourth arc portion and fifth arc portion are connected in an externally tangent way; the countersink portion also consists of a sixth arc portion and a second straight portion, and the second end of the fifth arc portion is connected with the first end of the sixth arc portion and the fifth arc portion and the sixth arc portion are connected in an internally tangent way; the second end of the sixth arc portion is connected with the first end of the second straight portion, and the sixth arc portion and the second straight portion are connected in a tangent way; the second end of the second straight portion is connected with the first end of the ferrule arc section and the second straight portion and the ferrule arc section are connected in a tangent way;

The radius of the fifth arc portion is greater than or equal to 0.25 mm and less than or equal to 2.5 mm;

The radius of the sixth arc portion is greater than or equal to 2 mm and less than or equal to 6.5 mm;

The radius of the ferrule arc portion is greater than or equal to 0.25 mm and less than or equal to 0.8 mm;

The junction of second straight portion and ferrule arc portion is defined as the auxiliary point, and the straight line vertical to the center panel through auxiliary point is defined as the auxiliary line A; the fifth arc portion, sixth arc portion and second straight portion are located at one side of the auxiliary line A and the ferrule arc section is located at the other side of the auxiliary line A;

The direction of the auxiliary line A is defined as up and down direction, and the side of basic shell facing the outside of can is up and the side of basic shell facing the inside of the can is down; in the up and down direction, the center of the sixth arc portion is located below the upper surface of the center panel;

The projection distance between the center of fourth arc portion and center of the fifth arc portion on the auxiliary line A is greater than or equal to 0.85 times of the sum of the radius of the fourth arc portion and the radius of the fifth arc portion, and less than or equal to the sum of the radius of the fourth arc portion and the radius of the fifth arc portion;

The projection distance between the center of fourth arc portion and center of the fifth arc portion perpendicular to the auxiliary line A is greater than or equal to 0, and less than or equal to 0.5 times of the sum of the radius of the fourth arc portion and the radius of the fifth arc portion.

Further, in the up and down direction, the junction of sixth arc portion and second straight portion is located below the upper surface of the center panel.

Further, the angle between the second straight portion and the auxiliary line A is 5°˜12°.

In order to achieve the above purpose, the technical solution for easy open end adopted by the present invention is: a pressure resistant easy open end, which consists of a basic shell and pull ring and the basic shell adopts the above-mentioned technical solution for the basic shell.

Further, in the up and down direction, the junction of sixth arc portion and second straight portion is located below the upper surface of the center panel.

Further, the angle between the second straight portion and the auxiliary line A is 5°˜12°.

In order to achieve the above purpose, the technical solution for can adopted by the present invention is: a pressure resistant can, which consists of a can shell and easy open end and the easy open end consists of a basic shell and pull ring and the basic shell adopts the above-mentioned technical solution for the basic shell.

Further, in the up and down direction, the junction of sixth arc portion and second straight portion is located below the upper surface of the center panel.

Further, the angle between the second straight portion and the auxiliary line A is 5°˜12°.

The design principle of the present invention is: the present invention is developed through the detailed research on the basis of the prior art for a whole year to find the effective method to lower the probability of breakage due to the failure of pressure resistance: add a sixth arc portion R 6 and a second straight portion L 2 for the countersink portion, get the reasonable dimension of fifth arc portion R 5 and sixth arc portion R 6 and the position relationship of centers of fourth arc portion R 4 and fifth arc portion R 5 through the detailed research to finally and successfully lower the probability of breakage to 0.05%˜2.5% due to the failure of pressure resistance. It has significantly improved the safety of use.

Under the same pressure resistance test conditions, the basic shells of prior art mostly break as shown in the FIG. 3 with the breakage probability of 80%; the basic shells of the embodiment in the present invention maintains the plump state, but doesn't break as shown in FIG. 4 and the breakage probability is only 0.05%˜2.5%.

The pressure resistance test comparison between the prior art and present invention is shown as follows:

On the other hand, as shown in FIG. 2 , the second straight portion L 2 of basic shell of present invention could form the surface contact with the can seaming mould 2 (commonly known as seaming head) during the can seaming to increase the contact area and significantly improve the stability of can seaming.

The present invention seems uncomplicated, but it brings about the above-mentioned unexpected effect, which is an important breakthrough in this field.

FIG. 1 is the schematic view of cross-section of the basic shell of embodiment 1 of present invention;

FIG. 2 is the schematic view of the joining of the basic shell of embodiment 1 of present invention with the can seaming mould during the can seaming;

FIG. 3 is the photo of the state after the pressure resistance test of the basic shell of prior art;

FIG. 4 is the photo of the state after the pressure resistance test of the basic shell of embodiment of present invention;

With reference to the accompanying drawings and embodiment, the present invention will be described in detail.

A pressure resistant basic shell as shown in the FIG. 1 consists of a can seaming portion, a countersink portion, a ferrule arc portion R 7 , an upward extension portion of ferrule and a center panel.

As shown in the FIG. 1 , the can seaming portion consists of first arc portion R 1 , second arc portion R 2 and third arc portion R 3 , which are connected in sequence, and the first arc portion R 1 is internally tangent to the second arc portion R 2 , and the second arc portion R 2 is internally tangent to the third arc portion R 3 .

As shown in the FIG. 1 , the countersink portion consists of a first straight portion L 1 , a fourth arc portion R 4 and a fifth arc portion R 5 , and the first end of first straight portion L 1 is connected with the corresponding end of can seaming portion, the second end is connected with the first end of fourth arc portion R 4 and the first straight portion L 1 is tangent to the fourth arc portion R 4 ; the second end of fourth arc portion R 4 is connected with the first end of fifth arc portion R 5 and the fourth arc portion R 4 is externally tangent to the fifth arc portion R 5 . The main point of the embodiment is: the countersink portion also consists of a sixth arc portion R 6 and a second straight portion L 2 , and the second end of the fifth arc portion R 5 is connected with the first end of the sixth arc portion R 6 and the fifth arc portion R 5 and the sixth arc portion R 6 are connected in an internally tangent way; the second end of the sixth arc portion R 6 is connected with the first end of the second straight portion L 2 , and the sixth arc portion R 6 and the second straight portion L 2 are connected in a tangent way. And the second end of the second straight portion L 2 is connected with the first end of the ferrule arc section R 7 and the second straight portion L 2 and the ferrule arc section R 7 are connected in a tangent way.

The radius of the fifth arc portion R 5 is greater than or equal to 0.25 mm and less than or equal to 2.5 mm; the radius of the sixth arc portion R 6 is greater than or equal to 2 mm and less than or equal to 6.5 mm; the radius of the ferrule arc section R 7 is greater than or equal to 0.25 mm and less than or equal to 0.8 mm.

As shown in the FIG. 1 , the junction of second straight portion L 2 and ferrule arc portion R 7 is defined as the auxiliary point Q 1 , and the straight line vertical to the center panel through auxiliary point Q 1 is defined as the auxiliary line A; the fifth arc portion R 5 , sixth arc portion R 6 and second straight portion L 2 are located at one side of the auxiliary line A and the ferrule arc section R 7 is located at the other side of the auxiliary line A.

As shown in the FIG. 1 , the direction of the auxiliary line A is defined as up and down direction, and the side of basic shell facing the outside of can is up and the side of basic shell facing the inside of the can is down; in the up and down direction, the center Y 6 of the sixth arc portion R 6 is located below the upper surface of the center panel L 4 ; As shown in the FIG. 1 , the projection distance H 1 between the center Y 4 of specific fourth arc portion R 4 and center Y 5 of the fifth arc portion R 5 on the auxiliary line A is greater than or equal to 0.85 times of the sum of the radius of the fourth arc portion R 4 and the radius of the fifth arc portion R 5 , and less than or equal to the sum of the radius of the fourth arc portion R 4 and the radius of the fifth arc portion R 5 .

The projection distance W 1 between the center Y 4 of fourth arc portion R 4 and center Y 5 of the fifth arc portion R 5 perpendicular to the auxiliary line A is greater than or equal to 0, and less than or equal to 0.5 times of the sum of the radius of the fourth arc portion R 4 and the radius of the fifth arc portion R 5 .

As shown in the FIG. 1 , it is preferred: in the up and down direction, the junction Q 2 of sixth arc portion R 6 and second straight portion L 2 is located below the upper surface of the center panel L 4 , and it could achieve the better anti-breakage performance.

As shown in the FIG. 1 , it is preferred: the angle α between the second straight portion L 2 and the auxiliary line A is 5°˜12°.

The upward extension portion of ferrule consists of a third straight portion L 3 and a eighth arc portion R 8 , and one end of the third straight portion L 3 is connected with the ferrule arc section R 7 in a tangent way, and its second end is connected with the eighth arc portion R 8 in a tangent way, and the second end of the eighth arc portion R 8 is connected with the center panel L 4 in a tangent way. A center panel L 4 could be a flat surface and could also be a substantially flat surface including a partially curved surface.

In the above embodiment, the dimension of the “arc portion” and “straight portion” refers to the dimension of the portion on the surface of the basic shell facing the outside of can (i.e. the up direction in the FIG. 1 ).

The break probability under the failure of pressure resistance of this embodiment is only 0.05%˜2.5%, which significantly improves the safety of use. Furthermore, as shown in FIG. 2 , the second straight portion L 2 of basic shell of present invention could form the surface contact with the can seaming mould 2 (commonly known as seaming head) during the can seaming to increase the contact area and significantly improve the stability of can seaming.

Embodiment 2: a pressure resistant easy open end, which consists of a basic shell and pull ring and the basic shell structure is the same as that described in embodiment 1 and will not be described here.

Embodiment 3: a pressure resistant can, which consists of a can shell and easy open end and the easy open end consists of a basic shell and pull ring, and the basic shell structure is the same as that described in embodiment 1 and will not be described here.

It should be noted that the above described embodiments are only for illustration of technical concept and characteristics of present invention with purpose of making those skilled in the art understand the present invention, and thus these embodiments shall not limit the protection range of present invention. The equivalent changes or modifications according to spiritual essence of present invention shall fall in the protection scope of present invention.