Can Covers And Cans Having The Same

Abstract

A can cover comprising: a top panel having an opening portion with a score line engraved on the top panel; a rotational tab rotatably installed on the top panel; and a severance initializing means for connecting the rotational tab and an area adjacent to the score line of the top panel to initialize a severance of the score line at a start point when the rotational tab is rotated.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of PCT International Patent Application No. PCT/KR2008/006087, filed Oct. 15, 2008, Korean Patent Application No. 10-2008-0055121, filed Jun. 12, 2008 and Korean Patent Application No. 10-2007-0104040, filed Oct. 16, 2007, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a can cover and a can, more particularly to a can cover and a can which enables easy opening of a lid by rotational movement.

[0004] 2. Description of the Related Art

[0005] FIG. 1 is a view showing a lid of the conventional cans. As shown in the drawing, the can has a cylindrical shaped body 1 and a lid 2 which is fastened on the top of the body 1.

[0006] The lid 2 is provided with an easily openable means for opening a discharge portion of the can. That is, a roughly circular shaped score line 3 is engraved on the lid 2 along the discharge portion, and a handle tab 4 is provided on the lid 2 for pressing a discharge portion with the score line 3. The handle tab 4 is fixed on the lid 2 by a rivet at the center portion thereof.

[0007] With the above configuration, when one end of the handle tab 4 is lifted, the other end of the handle tab 4 presses the discharge portion by a leverage to sever the score line 3. As the handle tab 4 is lifted more, the score line 3 continues to be severed so that the discharge portion is opened.

[0008] In the conventional cans, a user should lift the handle tab 4 by one hand while holding the can by the other hand.

[0009] Also, the gap between the handle tab 4 and the top panel of the can is very small and therefore the hooking of the finger is not favorable, and thus a user sometimes have to use a nail or other instrument for lifting the handle tab 4.

[0010] Further, lifting the handle tab 4 and pressing the discharge portion may results in an injury in fingers.

SUMMARY OF THE INVENTION

[0011] The present invention is designed to solve the above problems of the prior art. It is an object of the invention to provide a can cover in which a lid is easily openable by a rotational movement instead of the conventional push-and-up method which opens the lid by lifting and pressing the handle tab.

[0012] Also, another object of the present invention is to provide a can having the above can cover.

[0013] In order to accomplish the above object, the present invention provides a can cover comprising: a top panel having an opening portion with a score line S engraved on the top panel; a rotational tab rotatably installed on the top panel; and a severance initializing means for connecting the rotational tab and an area adjacent to the score line S of the top panel to initialize a severance of the score line S at a start point P.sub.o when the rotational tab is rotated.

[0014] Preferably, the severance initializing means comprises a severance protrusion provided on a position where the score line S is formed on the top panel to connect with the rotational tab.

[0015] More preferably, a severance slot is formed on the rotational tab to surround the severance protrusion, and the severance protrusion is configured to press the upper surface of the opening portion when the rotational tab is rotated.

[0016] Also, the score line S surrounds at least portion of the severance protrusion.

[0017] According to the invention, the top panel is provided with a concave section, and the concave section has a boundary adjacent to the score line S surrounding the severance protrusion.

[0018] Preferably, the rotational tab comprises a driving portion having a handle portion, and a driven portion opposite the driving portion which includes a push portion.

[0019] The score line S may comprise a main score line S.sub.m engraved along the boundary between the opening portion and the top panel; and an auxiliary score line S.sub.a extending in the opposite direction of the main score line S.sub.m.

[0020] Preferably, the invention may have a separation score line S.sub.s for separating the severance protrusion from the top panel during the progress of severance of the score line S.

[0021] More preferably, the separation score line S.sub.s extends in parallel to the auxiliary score line S.sub.a to lead to the main score line S.sub.m.

[0022] Also, the top panel may be provided with an embossment to be pressed by the severance protrusion.

[0023] According to another aspect of the present invention, there is provided a can comprising: a cylindrical shaped body for containing a beverage; and a can cover having the above configuration, to be fastened on the top of the body.

[0024] According to the present invention, a discharge portion of a can is easily opened by a simple action, i.e., rotating a rotational tab not by lifting and pressing the handle tab in the conventional can.

[0025] Also, since opening a discharge portion of the present invention does not require an excessive force and pressure, an injury resulting from the conventional can is prevented.

[0026] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

[0028] FIG. 1 is a partially perspective view showing a lid portion of the conventional can;

[0029] FIG. 2 is a partially perspective view schematically showing a lid portion of a can according to the preferred embodiment of the present invention;

[0030] FIG. 3 is a partially perspective view schematically showing a lid portion of FIG. 2 in which a rotational tab is omitted;

[0031] FIG. 4 is a plan view of FIG. 3;

[0032] FIG. 5 is a sectional view taken along the line A-A' of FIG. 2;

[0033] FIG. 6 is a sectional view taken along the line B-B' of FIG. 2;

[0034] FIG. 7 is a perspective view schematically showing a rotational tab provided in a can according to the preferred embodiment of the present invention;

[0035] FIG. 8 is a sectional view taken along the line a-a' of FIG. 7;

[0036] FIG. 9 is a sectional view taken along the line b-b' of FIG. 7;

[0037] FIG. 10 is a sectional view taken along the line c-c' of FIG. 7;

[0038] FIG. 11 is a sectional view taken along the line d-d' of FIG. 7;

[0039] FIG. 12 is a sectional view taken along the line e-e' of FIG. 7;

[0040] FIGS. 13 and 14 are plan views schematically showing a rotational tab provided in a can according to another preferred embodiment of the present invention, respectively;

[0041] FIG. 15 is a plan view schematically showing a lid portion of a can according to another preferred embodiment of the present invention;

[0042] FIG. 16 is a view showing a state in which a severance protrusion is bent in the operation of the present invention;

[0043] FIG. 17 is a partially perspective view schematically showing a rotational tab provided in a can according to still another preferred embodiment of the present invention, respectively;

[0044] FIG. 18 is a partially perspective view schematically showing a rotational tab provided in a can according to still yet another preferred embodiment of the present invention, respectively;

[0045] FIG. 19 is a sectional view taken along the line g-g' of FIG. 18;

[0046] FIG. 20 is a partially perspective view schematically showing a rotational tab provided in a can according to a further preferred embodiment of the present invention, respectively;

[0047] FIG. 21 is a sectional view taken along the line n-n' of FIG. 20 in which a severance protrusion is shown;

[0048] FIG. 22 is a plan view schematically showing a lid portion of a can according to still yet another preferred embodiment of the present invention; and

[0049] FIG. 23 is a plan view schematically showing a lid portion of a can according to a further embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

[0051] FIG. 2 is a perspective view showing a lid portion of a can according to a preferred embodiment of the present invention.

[0052] Referring to the drawing, a can of the invention comprises a cylindrical shaped body 10 with a can bottom for containing, for example, a beverage, and a lid 20 fastened on the top of the body 10 in which a discharge portion is opened by an opening means.

[0053] As well known, the body 10 is made of metal or plastic. The lid 20 is made of metal such as aluminum, steel and alloy thereof. The top portion of the body 10 gets wound together with the circumference of the lid 20 by a mechanical device to thereby connect each other, which is well know in the art and detailed description will be omitted.

[0054] The lid 20 of the invention comprises a top panel 21, and a rotational tab 30 which is rotatably installed in the top panel 21. FIGS. 3 and 4 show the lid in which the rotational tab 30 is removed.

[0055] As shown in the drawing, a score line S is engraved on the surface of the top panel 21 to thereby form an opening portion 23. As well known, the score line S is a severed line to facilitate opening of the opening portion 23, and the score line S has a circular shape except for a partial line.

[0056] The score line S may have a various curvature which facilitates a severance of the score line upon rotating the rotational tab 30.

[0057] Preferably, the score line S may have a pair of lines one of which is an outer score line that is engraved relatively deep so as to sever, and the other of which is an inner score line having a small depth just to assist the outer score in easily severing. To make it simple, the score line is denoted as a single line.

[0058] A rotational axis 24 is protruded at the center portion of the top panel 21 where the score line S is not formed, and the rotational tab 30 is connected with the rotational axis 24.

[0059] Specifically, referring to FIGS. 5 and 6 showing a sectional view taken along the lines A-A' and B-B' of FIG. 4, respectively, the rotational axis 24 integrally protruding from the top panel 21 of the lid 20 inserts into a rotational hole (see 31 in FIG. 7) formed on the rotational tab 30 and is riveted at the end to be fixed to the rotational tab 30 by a jaw portion (see 24a in FIG. 5).

[0060] A concave section 25 is formed on the top panel 21 underneath the rotational tab 30 where a finger may be easily inserted. Also, reinforcement ribs 26 may be formed on the opening portion 23 or other appropriate area to strengthen the lid 20.

[0061] According to the present invention, the concave section 25 has a boundary adjacent to the score line S surrounding the severance protrusion 27. In this case, stress may be concentrated on the circumference of the severance protrusion 27 when rotating the rotational tab 30 so that the score line is easily cut.

[0062] Here, the rotational axis 24 and the rotational tab 30 may be connected each other in various way.

[0063] FIG. 7 shows the rotational tab, and FIGS. 8 through 12 are sectional views taken along the line a-a', b-b', c-c-', d-d' and e-e' of FIG. 7, respectively. Here, FIG. 10 illustrates a sectional view in connection with the severance protrusion 27.

[0064] Referring to the drawings, the rotational tab 30 has a rotational hole 31 through which the rotational axis 24 is inserted. Also, the rotational tab 30 is provided with a driving portion 30a that is rotated by a finger and a driven portion 30b opposite the driving portion with respect to the rotational hole 31.

[0065] Preferably, the driving portion 30a is longer than the driven portion 30b to have a leverage effect, but not limited to this configuration.

[0066] The rotational tab 30 is preferably made of hard metal such as steel, aluminum and alloy thereof. A handle portion 32 is formed to be bent upward on the driving portion 30a of the rotational tab 30 so that hooking of finger is easy for rotation.

[0067] Preferably, a push portion 33 is provided on the driven portion 30b opposite the handle portion 32 to enable a user to push by fingers. For example, the push portion 33 may be formed by bending the edge of the rotational tab 30 as shown in FIG. 12.

[0068] With the above configuration, a user hooks the handle portion 32 by his thumb and pushes the push portion 33 by his index finger to thereby rotate the rotational tab 30 in the direction of the arrow in FIG. 2. In this case, since the rotational tab 30 is biased at both ends at the same time, it may be easily rotated.

[0069] Reference numeral 34 denotes a reinforcement hole to strengthen the rotational tab 30 in FIG. 7.

[0070] The rotational tab of the invention is rotated to open the cam lid, which is a different characteristic from the prior art so that the rotational tab may have a various design to facilitate hooking of finger, pushing and rotation as exampled in FIGS. 13 and 14.

[0071] FIG. 15 is a plan view of a can cover according to a preferred embodiment of the invention similar to FIG. 4. Hereinafter, the configuration of the can cover will be described with reference to FIG. 15.

[0072] According to the present invention, there is provided a severance initializing means for initializing a severance of the score line S when the rotational tab 30 is rotated. The severance initializing means also connects the rotational tab 30 and an area adjacent to the score line S of the top panel 21 each other.

[0073] It is understood that the severance initializing means may be modified into various members that connects the rotational tab 30 and the area adjacent to the score line S of the top panel 21 as set forth below.

[0074] According to the present embodiment, the severance initializing means comprises a severance protrusion 27 which is formed on the top panel 21 to insert into a connection hole 35 on the rotational tab 30.

[0075] Specifically, the connection hole 35 is formed at one side of the rotational hole (31 of FIG. 7) on the rotational tab 30, and the severance protrusion 27 fits into the connection hole 35(see FIGS. 6 and 10).

[0076] Also, a severance slot 36 is formed on the surrounding area of the severance protrusion 27. The severance slot 36 functions to promote the easy break of the severance protrusion 27 when the rotational tab 30 rotates to open the can lid. To do so, the severance slot 36 is located in the direction of rotation of the rotational tab 30.

[0077] Preferably, a break groove 37 in FIG. 7 is provided on the lower surface of the rotational tab 30 to ease the break of the severance protrusion 27. More preferably, a plurality of reinforcement protrusions (see 38 in FIGS. 7 and 11) may be formed on the rotational tab 30 adjacent to the break groove 37.

[0078] The severance protrusion 27 is located adjacent to a position where the score line S begins to sever. The severance protrusion 27 is inserted into the connection hole 35 and riveted at the end to be fixed to the rotational tab 30.

[0079] The severance protrusion 27 breaks in the rotational direction of the rotational tab 30 to initialize the severance of the score line S.

[0080] Preferably, the severance protrusion 27 presses down the upper surface of the opening portion 23 upon the initialization of severance so that the score line S keeps severing to open the opening portion 23.

[0081] According to the present invention, the score line S may be designed in shape and position so as to facilitate the initialization of severing upon a rotation of the rotational tab 30 and the progress of severance, one example of which is illustrated in FIG. 15.

[0082] For facilitation of severance a start point P.sub.o of the score line S is located adjacent to the severance protrusion 27, and a main score line S.sub.m and an auxiliary score line S.sub.a extends bilaterally from the start point P.sub.o to surround at least portion of severance protrusion 27.

[0083] The main score line S.sub.m is engraved along the boundary between the opening portion 23 and the top panel 21 so that the opening portion 23 is opened upon the severance of the main score line S.sub.m. The auxiliary score line S.sub.a extends in the opposite direction of the main score line S.sub.m to assist in opening the opening portion 23 and the severance of the auxiliary score line S.sub.a is relatively retarded compared to the main score line S.sub.m. To do so, the auxiliary score line S.sub.a has a smaller depth in partial than the main score line S.sub.m.

[0084] According to the present invention, there is provided a separation score line S.sub.s for separating the severance protrusion 27 from the top panel 21 during the progress of severance of the score line S.

[0085] The separation score line S.sub.s is engraved on the top plate 21 to surround at least portion of the severance protrusion 27. Preferably, the separation score line S.sub.s extends in parallel to the auxiliary score line S.sub.a to lead to the main score line S.sub.m with the separation protrusion 27 located therebetween.

[0086] According to the preferred embodiment of the present invention, the score lines S may have different depth from one another. That is, at least portion of the auxiliary score line S.sub.a may have a depth smaller than the main score line S.sub.m.

[0087] Accordingly, the score line having a large depth severs prior to the score line having a small depth when the rotational tab 30 is rotated. The depth of the score lines would be determined for the sequence of severance as desired.

[0088] According to the present invention, a facilitation line is formed on the top panel 21 to ease the severance of the score lines S. Specifically, a facilitation line 28a is formed at inner side of the main score line S.sub.m to ease the severance of the main score line S.sub.m, and other facilitation line 28b is formed on the top panel 21 between the boundary of the concave section 25 and the score line S surrounding the severance protrusion.

[0089] Such facilitation lines 28 may be formed by engraving the top panel to the depth smaller than the score lines.

[0090] More preferably, the top panel 21 has an embossment 29 on the upper surface which is pressed by the severance protrusion 27 in contact so as to bend the opening portion 23 during the rotation of the rotational tab 30.

[0091] More preferably, the embossment 29 may have hemispheric or corn shape, but not limited to the shape. Alternatively, a plurality of embossments 29 may be provided or formed consecutively.

[0092] Reference numeral 41 denotes a reinforced embossment in FIG. 15.

[0093] The operation of opening the can lid of the present invention now will be described.

[0094] A user is able to open the can lid by rotating the rotational tab 30 with a finger while holding the can in one hand. That is, the rotational tab 30 is rotated in the direction of arrow of FIG. 2 by hooking the handle portion 32 of the driving portion 30.

[0095] Then, the rotational tab 30 rotates clockwise about the rotational axis 24. Preferably, the user may rotate the rotational tab 30 with hooking the handle portion 32 by an index finger and pushing the push portion 33 by a thumb.

[0096] During the above rotation of the rotational tab 30, the severance protrusion 27 on the driven portion 30b rotates in the direction of dotted arrow in FIG. 15 to initialize the severance of the score lines S.

[0097] Shortly after the rotational tab 30 begins to rotate, the portion where the severance protrusion is connected collapses downward due to the severance slot 36 so that the severance protrusion 27 is bent in the rotated direction.

[0098] In this case, the severance slot 36 functions to decrease the initial force required to bend the severance protrusion 27. Once the severance protrusion 27 is bent, the driving force of the rotational tab 30 is directly transferred to the severance protrusion 27. At this time, the severance protrusion 27 is facilitated to be bent due to the break groove 37 on the lower surface of the rotational tab 30.

[0099] With the above operation, the score lines S surrounding the severance protrusion 27 begin to sever at the start point P.sub.o. That is, as shown in (a) and (b) of FIG. 16, the start point P.sub.o of the score lines S begins to sever while the rotational tab 30 is bent at the position of the break groove 37.

[0100] Such a severance of the score line progresses to the point P.sub.2 and point P.sub.3 through the main score line S.sub.m and the auxiliary score line S.sub.a.

[0101] When the severance of the score line progresses to the point P.sub.3 where the main score line S.sub.m and the separation score line S.sub.s meet each other during the rotational of the rotational tab 30, the separation score line S.sub.s begins to sever from point P.sub.3 to point P.sub.4.

[0102] With the severance of the separation score line S.sub.s, the severance protrusion 27 is fully bent and presses the opening portion 23 in contact with the upper surface of the opening portion 23 as shown (c) in FIG. 16. Then, the opening portion 23 begins to collapse downward.

[0103] Meanwhile, the auxiliary score line S.sub.a from the point P.sub.2 to point P.sub.8 has a relatively shallow depth, which guide the severance protrusion 27 to sever toward the inner side of the can.

[0104] As the rotational tab 30 rotates more, the separation score line S.sub.s and the main score line S.sub.m sever at the same time from point P.sub.4 to point P.sub.5 and from point P.sub.3 to point P.sub.6, respectively.

[0105] Accordingly, the severance protrusion 27 moves in the direction of the dotted arrow in FIG. 15 while pressing the upper surface of the opening portion 23. At this time, the severance of the main score line S.sub.m progresses to the point P.sub.7 along the circular arc.

[0106] During the severance of the main score line S.sub.m from the point P.sub.6 to the point P.sub.O7, the auxiliary score line S.sub.a severs from the point P.sub.2 to the point P.sub.8.

[0107] Such a severance of the auxiliary score line S.sub.a and the separation score line S.sub.s results in a strip 42 which links the severance protrusion 27 with the top panel 21.

[0108] When the main score line S.sub.m is severed to the point P.sub.7 by the rotation of the rotational tab 30, the opening portion is fully opened due to the pressure of the severance protrusion 27 with respect to the upper surface of the opening portion 23, which enables a user to drink beverages or something like that.

[0109] Preferably, since the upper surface of the opening portion 23 is provided with an embossment 29 which is pressed by the severance protrusion 27, the opening portion 23 is effectively opened with the rotation of the rotational tab 30.

[0110] FIG. 17 shows a rotational tab according to another preferred embodiment of the present invention, wherein the identical elements consequently bear the same reference numerals of the previous drawings.

[0111] In the present embodiment, bent members 39 are provided at the break groove 37 on the rotational tab, and openings 39a having a width larger than that of the bent member are formed between the bent members 39. Accordingly, the bent members 39 are easily bent due to the openings 39a upon the rotation of the rotational tab.

[0112] Additionally, openings 39b are provided adjacent to the push portion 33 to facilitate the bend of rotational tab.

[0113] FIGS. 18 and 19 show a rotational tab according to still another preferred embodiment of the present invention, wherein the identical elements consequently bear the same reference numerals of the previous drawings.

[0114] A rotational tab of the resent invention has bent members 39 around the break groove 37, and a portion 40 adjacent to the push portion 33 with respect to the bent members 39 declines downward.

[0115] Accordingly, the bent members 39 are easily bent due to the declined portion 40 during the rotation of the rotational tab.

[0116] Preferably, a plurality of slits 43 are formed on the declined portion for reinforcement.

[0117] FIGS. 20 and 21 show a rotational tab according to still another preferred embodiment of the present invention, wherein the identical elements consequently bear the same reference numerals of the previous drawings. FIG. 21 is a view taken along the line n-n' in FIG. 20, wherein the severance protrusion is provided.

[0118] A rotational tab of the present embodiment comprises an extended portion 51 extending downward from the body of the rotational tab, and a connection portion 52 extending horizontally from the extended portion 51.

[0119] The connection portion 52 is provided with a connection hole 35 in which the severance protrusion 27 inserts as set forth above.

[0120] Also, the extended portion 51 has a plurality of slits 53.

[0121] When the rotational tab of the present embodiment is rotated for opening the can, the extended portion 51 is bent to collapse the severance protrusion 27. At this time, the extended portion 51 is easily bent by a small force because it has a plurality of slits 53. On the contrary, the connection portion 52 is reinforced by folding the edge thereof.

[0122] The can covers of the present invention may have a various mechanism of severance depending on the form of score lines. FIG. 22 illustrates score lines according to another preferred embodiment of the present invention.

[0123] In the present embodiment, when the rotational tab 30 is rotated, the severance protrusion 27 collapses in the same manner as the previous embodiment to initialize the severance of a score lines S at a start point P.sub.o. Subsequently, a main score line S.sub.m and an auxiliary score line S.sub.a sever to a point P.sub.2 and a point P.sub.3, respectively,

[0124] And then, a separation score line S.sub.s begins to sever from a point P.sub.4 where the main score line S.sub.m and the separation score line S.sub.s meet each other to a point P.sub.5.

[0125] As the rotational tab rotates more, the severance of the main score line S.sub.m progresses from the point P.sub.3 to a point P.sub.6, and from the point P.sub.2 to a point P.sub.8.

[0126] After that, the main score line severs from the point P.sub.6 to a point P.sub.9, and the auxiliary score line S.sub.a severs from the point P.sub.5 to a point P.sub.7. At this time, the severance protrusion 27 presses the opening portion while it is linked with the opening portion 23 by means of a strip 42 as the same as in the previous embodiment.

[0127] FIG. 23 illustrates score lines according to another preferred embodiment of the present invention.

[0128] In the present embodiment, a severance protrusion 27 collapses and score lines S begins to sever from a start point P.sub.o during the rotation of the rotational tab. The severances of a main score line S.sub.m and an auxiliary score line S.sub.a progress to a point P.sub.2 and a point P.sub.5, respectively.

[0129] Then, a separation score line S.sub.s severs from a point P.sub.3 where the main score line S.sub.m and the separation score line S.sub.s meet each other while the auxiliary score line and the main score line sever to a point P.sub.4 and a point P.sub.7, respectively.

[0130] As the rotational tab is rotated more, the separation score line S.sub.s and the main score line S.sub.m sever to a point P.sub.8 and a point P.sub.9, respectively. Like the above, the severance protrusion 27 presses the opening portion 23 in connection with the opening portion 23 by a strip 42 from the point P.sub.6 to the pointy P.sub.8.

[0131] The present invention has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Claims

1. A can cover comprising: a top panel having an opening portion with a score line engraved on the top panel; a rotational tab rotatably installed on the top panel; and a severance initializing means for connecting the rotational tab and an area adjacent to the score line of the top panel to initialize a severance of the score line at a start point when the rotational tab is rotated.

2. The can cover according to claim 1, wherein the severance initializing means comprises a severance protrusion provided on a position where the score line is formed on the top panel to connect with the rotational tab.

3. The can cover according to claim 2, wherein a severance slot is formed on the rotational tab to surround the severance protrusion.

4. The can cover according to claim 3, wherein the severance protrusion is configured to press the upper surface of the opening portion when the rotational tab is rotated.

5. The can cover according to claim 2, wherein the score line surrounds at least portion of the severance protrusion.

6. The can cover according to claim 2, wherein the top panel is provided with a concave section, and the concave section has a boundary adjacent to the score line surrounding the severance protrusion.

7. The can cover according to claim 1, wherein the rotational tab comprises a driving portion having a handle portion, and a driven portion opposite the driving portion which includes a push portion.

8. The can cover according to claim 1, wherein the score line comprises: a main score line engraved along the boundary between the opening portion and the top panel; and an auxiliary score line extending in the opposite direction of the main score line.

9. The can cover according to claim 8, further comprising a separation score line for separating the severance protrusion from the top panel during the progress of severance of the score line.

10. The can cover according to claim 9, wherein the separation score line extends in parallel to the auxiliary score line to lead to the main score line.

11. The can cover according to claim 2, wherein the top panel is provided with an embossment to be pressed by the severance protrusion.

12. A can comprising: a cylindrical shaped body for containing a beverage; and a can cover having the configuration of claim 1, to be fastened on the top of the body.