JPH0385254A - Can lid - Google Patents

Abstract

PURPOSE:To prevent the growing direction of a crack from shifting from a cut by forming an uneven shape on a can lid opening face directly coupled with a can opening pull ring. CONSTITUTION:An uneven shape 9 approximately similar to the shape of a can lid opening 2 is provided inner periphery of the can lid opening 2 to increase durability of said part as well as change flow of stress. Thus with any opening opening operation of the can lid opening 2, a crack always grows along a cut 3 to prevent the crack from vertically crossing the can lid opening.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a can lid that can be applied to aluminum cans and steel cans for beer, various beverages, etc.

(Prior Art) Each side of the lid of a conventional aluminum beer can will be explained with reference to FIGS. 6, 7, and 8. First, in Fig. 6, reference numeral 1 denotes a can lid, which is molded separately from the can body, and its peripheral edge 1' is tightly fitted to the opening peripheral edge of the can body (not shown) by can tightening processing using a can seamer to maintain airtightness. ing. Reference numeral 2 denotes a can lid opening section which is formed in a fan shape with cuts 3 extending from the center of the can lid 1 toward the outer circumference.When the opening section 2 is opened, the liquid inside the can can flow out. Reference numeral 4 denotes a convex portion formed around the can lid opening 2 to increase the rigidity of the can lid 1 when the opening 2 is opened. The cut 3 is made by pressing the rigid body to form the outline of the can lid opening 2.
It is formed in a groove shape as shown in Figure (C). Further, a can opening trigger 5 is fixed at the center of the can lid 1 in the can lid opening 2 by caulking with a pin 6. 5' is a hole for a finger rest formed in the can opening trigger 5.

Now, lift the can opening trigger 5 slightly from one side of the can lid, and open the hole 5'.
When you put your finger on it and pull it up and pull it in the outer circumferential direction, a crack appears at the cut 3 part, separating the can lid opening 2 from the main body of the can lid 1, and separating the can lid opening 2 from the can lid opening 2 as shown in Fig. 7. The opening can be made as shown below.

(Problem to be Solved by the Invention) If the can opening trigger 5 is obediently pulled up just above the can lid 1 in FIG. Section 2 separates from cut 3. However, if an unexpected tensile or bending load is applied, such as by pulling up the can opening trigger 5 diagonally, the can lid opening 2 will be flat and not very rigid, causing a crack 8 to open from the middle as shown in FIG. 3, the can lid opening 2 may be cut vertically, and the opening 7 is small and a sufficient opening area cannot be obtained. Whether or not the crack 8 generated at the cut 3 will extend to the end along the cut 3 requires analysis of fracture mechanics. There are three crack modes: open type, in-plane shear type, and out-of-plane shear type, and the growth direction of the crack is determined by the combination of these types. Since the cut 3 has already been formed, the length will be extended along this line under a normal load, but this will not happen under an abnormal load.

The present invention attempts to solve the above-mentioned problems of the prior art by providing unevenness on the opening surface of the can lid so that cracks will grow along the cuts under any load.

(Means for Solving the Problems) Therefore, in a can lid that opens the can lid opening by pulling up the can opening trigger, the present invention forms an uneven shape on the can lid opening surface that is directly connected to the can opening trigger. It is a means to solve problems.

(Function) By creating irregularities on the surface of the can lid opening, the rigidity of the can lid opening increases and the flow of stress changes, allowing the can opening trigger to be pulled up diagonally instead of just straight up. Also, the direction of crack growth is less likely to deviate from the cut.

(Embodiments) The present invention will be described below with reference to embodiments of the drawings. Figs. 1 to 5 show first to fifth embodiments of the present invention. First of all
To explain the first embodiment in the figure, 1 in the figure is a can lid;
' is the can lid periphery, 2 is the can lid opening, 3 is the cut, 4 is the convex part, 5 is the can opening trigger, 5' is the hole for the finger rest, and 6 is the pin, these are shown in Figure 6. Since these are the same as those in the prior art, detailed explanations thereof will be omitted here. The difference in Fig. 1 from the conventional one is that the inner part of the can lid opening 2 is provided with an unevenness 9 having a shape almost similar to that of the opening 2, thereby increasing the rigidity of the same part and changing the flow of stress. Therefore, no matter how the can lid opening 2 is opened, cracks will always form at the cut 3.
There are no cracks running vertically along the opening of the can lid.

Next, FIG. 2 shows a second embodiment, in which the unevenness 9 formed on the 2 surfaces of the can lid opening is aligned with the radial bisecting line of the fan-shaped can lid opening 2 that passes through the pin 6. On the other hand, in the perpendicular direction, it is formed into a plurality of parallel rod shapes, with a short one at the center and a long one at the outer periphery.

Further, the unevenness 9 in the third embodiment shown in FIG.
The unevenness 9 in the embodiment is formed into a substantially horseshoe shape extending from the center to the outer periphery, and the unevenness 9 in the fifth embodiment shown in FIG. However, there is no difference in operation and effect between these unevenness 9 compared to the unevenness shown in FIG.

(Effects of the Invention) As explained in detail above, the present invention has an uneven shape formed on the surface of the can lid opening, so that the rigidity of the can lid opening is increased.
The flow of stress has also changed, and no matter how much the can opening trigger is pulled up, the crack will now grow along the cut until the end. There are no drawbacks such as insufficient opening area.

[Brief explanation of drawings]

FIG. 1(a) is a plan view of a can lid showing a first embodiment of the present invention, FIG. 1(b) is a sectional view taken along line AA in FIG. 1(a), FIGS. 4 and 5 are plan views of can lids showing second to fifth embodiments of the present invention, FIG. 6(a) is a plan view of a conventional can lid, and FIG. B-8 cross-sectional view in Figure (a), Figure 6 (C) is an enlarged cross-sectional view along CC in Figure 6 (a), Figure 7 is the can lid opening in Figure 6 (a) removed. FIG. 8 is a plan view of the can lid in a state where a vertical crack has occurred in the can lid opening. Explanation of main parts of the figure 1...Can lid 2--Can lid opening 3--
- Cut 5 - Can opening trigger 6 - Bottle
9-Irregularities Fig. 1 (a), 6' M2 Fig. 3 Fig. 5' Fig. 4 yA5 Fig. 5' J! ! Figure 6 Akira Figure 7

Claims (1)

[Claims] A can lid that opens a can lid opening by pulling up a can opening trigger, characterized in that an uneven shape is formed on a surface of the can lid opening that is directly connected to the can opening trigger.