JP2000271317A - Game machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a display device from being illegally operated by arranging an illegal intrusion preventing means for preventing the insertion of a illegal intrusion matter in the direction of the display device inside of a game machine from a gap which is formed between a front surface cover member and a front surface frame in the state of closing the front surface cover member. SOLUTION: A front surface cover member 120 is fitted to the front surface frame 110 of a slot machine in a singly swinging style in a closable manner. The frame 110 has an opening part 110A nearly in a center and a display device 40 is fixed to the part 110 A in the state of locking the part 110A. An illegal intrusion preventing member 111 on the metallic front surface frame constituting a first projecting part 111a is fixed to the front surface side of the frame 110 at a position corresponding to the first groove part 121a of a cover-side illegal intrusion preventing member 121 of the member 120. The part 111a of the member 111 is fitted into the part 121a of the member 121 in the state of closing the member 120.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device capable of variably displaying a plurality of types of identification information by performing a switch operation by betting a ball, a front frame to which the display device is attached, and a front frame. And a front cover member attached to the display device so as to be openable and closable so as to cover the display device.

[0002]

2. Description of the Related Art Conventionally, a display device capable of changing (circularly displaying) a plurality of types of identification information (for example, symbols) by betting a ball (for example, a pachinko ball) and performing a switch operation, and the display. A front frame to which the device is attached, and a front cover member that is attached to the front frame so as to be openable and closable to cover the display device, and the result of stopping the variable display is a predetermined result mode. In such a case, a gaming machine (slot machine) capable of providing a required number of prize balls according to the content of the result mode has been proposed.

[0003]

However, in the above-mentioned conventional gaming machine, the front cover member is attached to the front frame so as to be openable and closable. Therefore, even when the front cover member is closed, the front cover member and the front frame are not attached. There is a risk that a wire (illegal intrusion) or the like may be inserted from a gap formed between the gaps, and a display device inside may be illegally operated. For example, if the display device is operated improperly and the stop result of the variable display is changed to a result mode of generating a jackpot bonus game (special game state), the gaming shop may suffer a great deal of damage. There was sex.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an illegal intruder such as a wire is inserted from a gap formed between a front cover member and a front frame to display the display device. It is an object of the present invention to provide a gaming device capable of preventing illegal operation of a game device.

[0005]

According to a first aspect of the present invention, there is provided a display device (40) capable of variably displaying a plurality of types of identification information by betting a ball and performing a switch operation. ), A front frame (110) to which the display device is attached, and a front cover member (120) attached to the front frame so as to be openable and closable to cover the display device. In a gaming machine (for example, a slot machine 100 or the like) capable of providing a required number of prize balls according to the content of the result mode, when the stop result of the predetermined result mode is obtained, the front cover member In a closed state, unauthorized intrusion prevention that prevents an unauthorized intruder from being inserted in the direction of the display device inside the gaming device from a gap formed between the front cover member and the front frame. hand (E.g., the protruding portion 111a and the groove 121a) and configured to include a.

According to the first aspect of the present invention, the gap formed between the front cover member and the front frame when the front cover member is closed is illegal in the direction of the display device inside the gaming machine. Since the intrusion prevention means for preventing the intruder from being inserted is provided, it is possible to prevent the display device inside the gaming device from being illegally operated by the intruder. Therefore, it is possible to prevent damage to the game store caused by an illegal act using the illegal intruder.

[0007] The identification information includes identification symbols (identification marks) that can be visually identified, such as numbers, characters, symbols and characters, and colors.

According to a second aspect of the present invention, in the gaming machine according to the first aspect, the unauthorized intrusion preventing means is provided in a first groove provided on a back side of the front cover member along an edge of the front cover member. (121a) and a first protrusion (111a) provided on the front side of the front frame and fitted in the first groove when the front cover member is closed. Means were included.

According to the second aspect of the present invention, when the front cover member is closed, the first projecting portion is fitted into the first groove and is formed between the front cover member and the front frame. The gap makes it impossible to insert an unauthorized intruder into the gaming device.

According to a third aspect of the present invention, in the gaming machine according to the second aspect, a portion (for example, the front frame side unauthorized intrusion preventing member 11) constituting the first protrusion and the first groove is provided.
1, the cover-side unauthorized entry prevention member 121, etc.) are all made of metal.

According to the third aspect of the present invention, since the portions forming the first protruding portion and the first groove are both made of metal, for example, a heated wire or the like is used as an unauthorized intruder. However, the unauthorized intruder does not penetrate through the first protrusion and the first groove, and therefore, it is possible to prevent such an unauthorized intruder from entering the inside of the gaming machine.

According to a fourth aspect of the present invention, in the gaming machine according to the second or third aspect, at least one of the first groove and the first protrusion is coated with an elastic material (121b). When the first protrusion is fitted into the first groove, the elastic member is elastically deformed, so that the first protrusion and the first groove come into close contact with each other.

According to the fourth aspect of the present invention, at least one of the first groove and the first protrusion is coated with an elastic material, and the first protrusion is fitted into the first groove. In the first, the elastic material is elastically deformed, so that the first
Since the projection and the first groove are in close contact with each other, it is difficult for a gap to be formed between the first groove and the first projection when the first projection is fitted into the first groove. Therefore, it becomes more difficult to insert an unauthorized intruder into the inside of the gaming device from the gap formed between the front cover member and the front frame.

According to a fifth aspect of the present invention, in the gaming machine according to any one of the first to fourth aspects, the display device is a display unit (for example, a variable display unit 41a) on which the plurality of types of identification information are displayed. , 41b, 41c, etc.), and the second intrusion prevention means (113A, 1A, 1B) is provided in a state where the unauthorized intrusion prevention means protrudes forward from between the adjacent display units.
13B), provided on the back side of the front cover member,
A second groove (123A, 123B) into which the second protrusion fits when the front cover member is closed, and a second unauthorized intrusion prevention means.

According to the fifth aspect of the present invention, when the front cover member is closed, the second projecting portion is fitted into the second groove, and an unauthorized intruder is inserted into each display portion of the display device. It is difficult to do this. In addition, the intrusion prevention means,
In the case where the first unauthorized intrusion prevention means is included in addition to the second unauthorized intrusion prevention means, the first unauthorized intrusion prevention means is broken and an unauthorized intruder is inserted inside the gaming machine. Even if it does, the inserted unauthorized intruder will not be able to reach each display unit of the display device because the second unauthorized intrusion prevention means is an obstacle. Therefore, unauthorized operation of the display device can be reliably prevented.

According to a sixth aspect of the present invention, in the gaming machine according to the fifth aspect, portions (for example, the casing of the display device 40, the side wall 122) forming the second protrusion and the second groove are provided.
a, 122b, 122c, 122d, 122e, 122
f, etc.) are all made of metal.

According to the sixth aspect of the present invention, since the portions forming the second protrusion and the second groove are both made of metal, for example, a heated wire or the like is used as an unauthorized intruder. However, an unauthorized intruder does not penetrate through the second protrusion and the second groove, so that it is possible to prevent such an unauthorized intruder from entering the display device.

According to a seventh aspect of the present invention, in the gaming machine according to the fifth or sixth aspect, at least one of the second groove and the second protrusion is coated with an elastic material (124). The elastic member is elastically deformed in a state where the second projecting portion is fitted in the second groove, so that the second projecting portion and the second groove come into close contact with each other.

According to the present invention, at least one of the second groove and the second protrusion is covered with an elastic material, and the second protrusion is fitted into the second groove. , The elastic material is elastically deformed,
Since the protrusion and the second groove are in close contact with each other, it is difficult for a gap to be formed between the second groove and the second protrusion when the second protrusion is fitted into the second groove. Therefore, it becomes more difficult to insert an unauthorized intruder into the display device.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 is a front view showing a slot machine exemplified as a gaming machine according to the present invention. FIG. 2 is a perspective view showing the slot machine, showing a state in which a front cover member is opened. FIG. 3 is a sectional view of FIG.
FIG. 4 is a cross-sectional view of a portion corresponding to a view taken in the direction of arrow A. FIG.
It is a cross-sectional view of a part corresponding to the arrow. FIG. 5 shows the first unauthorized intrusion prevention means shown in FIG. 3 and the second unauthorized intrusion prevention means shown in FIG.
FIG. 4 is a cross-sectional view showing the positional relationship of the unauthorized intrusion prevention means.

The slot machine 100 according to this embodiment
Is a slot machine using a ball (pachinko ball) as a game medium. A front cover member 120 is attached to a front frame 110 of the slot machine so as to be openable and closable in a single-opening manner with the left end as an axis, as shown in FIG. ing.

As shown in FIG. 1, above the front cover member 120, a special game state indicator 12, which displays the degree of progress of the special game state (big hit bonus game),
, And a completion lamp 11 are provided.

At the center of the front cover member 120, three windows 4a, 4b, 4c made of a transparent material are provided, and through the windows 4a, 4b, 4c, the variable display portions 41a, 41b of the display device 40 are provided. , 41c (to be described later) can be seen one by one. Below the windows 4a, 4b, 4c, stop possible indicators 3a, 3b, 3c indicating that the stop switches 2a, 2b, 2c corresponding to the respective variable display units 41a, 41b, 41c are effective, A max bet switch 8 for setting the number of bets on balls to the maximum (for example, 15 balls) is provided. On the right side of the window 4c, there are provided a credit number display 13 for displaying the number of balls (the number of credits) stored as credit balls, a prize ball number display 14 for displaying the prize ball number, and the like. . On the left side of the window 4a, a line indicator (not shown) for displaying an effective line corresponding to the number of bets on the ball is provided.

The rear side of the front cover member 120 has a structure shown in FIG.
As shown in the figure, metal side walls 122a, 122b, 122 are provided rearward from both sides of each of the windows 4a, 4b, 4c.
c, 122d, 122e, 122f are protruded.
Then, between the side walls 122b and 122c and the side wall 1
In the state where the front cover member 120 is closed, as shown in FIGS. 4 and 5, between the side wall 122e and the second protruding portion 113 provided on the front frame 110 side.
A, 113B (to be described later) can be fitted into the second groove 1
23A and 123B are formed. These second grooves 1
The inner peripheral surfaces of 23A and 123B are covered with elastic materials (for example, rubber) 124 and 124, and the elastic materials are provided in a state where the second protrusions 113A and 113B are fitted into the second grooves 123A and 123B, respectively. Each of the second protrusions 113A, 1
13B and the second groove portions 123A, 123B are improved in adhesion. Also, the side wall 1 among the side walls
22a and 122f are provided so as to protrude rearward from the other side walls, and are arranged so as to cover the side portions of the driving means 42a and 42c of the display device 40 when the front cover member 120 is closed. You.

On the back side of the front cover member 120, as shown in FIG. 2, a metal cover-side unauthorized entry prevention member 121 having a first groove 121a opened rearward along the peripheral edge thereof. Installed. In the first groove 121a of the cover-side unauthorized entry prevention member 121, with the front cover member 120 closed, as shown in FIGS. 3 and 5, the front frame-side unauthorized entry prevention member attached to the front frame 110. 111 (to be described later)
a is fitted. Then, the first groove 12
An elastic material (for example, rubber) 121 is provided on the inner peripheral surface of 1a.
b, the elastic member 121b is elastically deformed in a state where the first protrusion 111a is fitted into the first groove 121a, so that the adhesion between the first protrusion 111a and the first groove 121a is enhanced. It has become.

As shown in FIG. 2, the front frame 110 has an opening 110A substantially at the center thereof.
, The display device 40 is attached so as to close the opening 110A. The display device 40 includes upper and lower rollers 43a, 43a, 43b, 43b, 43c, 4
Belt-type fluctuation display sections 41a, 41 circulating between 3c
b, 41c and these variable display sections 41a, 41b, 41
c respectively driving means 42a, 42b, 42c
And Variable display sections 41a, 41b, 41c
A pattern (identification information) row is formed on the outer peripheral surface in the circumferential direction, and these variable display sections 41a, 41b, 41c
Are circulated, so that the symbols are variably displayed (circularly displayed) through the windows 4a, 4b, 4c.
Each of the variable display portions 41a, 41b, and 41c is configured to stop sequentially when a predetermined time elapses after the start switch 1 (described later) is pressed or when the corresponding stop switches 2a, 2b, and 2c (described later) are pressed. In the state where each of the variable display portions 41a, 4B, and 41c is stopped, three stop displays of symbols (including blanks) can be seen from each of the windows 4a, 4b, and 4c. Then, the combination mode of the stop display (stop result mode)
Is a predetermined result mode, a required number of prize balls are given to the player according to the content of the result mode.

Then, the fluctuation display section 41a and the fluctuation display section 4
1b, and between the change display portions 41b and 41c, that is, the second groove 123A of the front cover member 120,
The second protrusion 11 made of metal is provided at a position corresponding to 123B.
3A and 113B are provided so as to protrude forward. As described above, these second protrusions 113A and 113B are in a state where the front cover member 120 is closed.
The second grooves 123A and 123B are fitted.

On the front side of the front frame 110, as shown in FIG. 2, a first protrusion 111a is formed at a position corresponding to the first groove 121a of the cover-side unauthorized entry prevention member 121 of the front cover member 120. A metal front frame side unauthorized intrusion prevention member 111 is attached. As described above, the first protrusion 111a of the front frame-side unauthorized entry prevention member 111 fits into the first groove 121a of the cover-side unauthorized entry prevention member 121 when the front cover member 120 is closed. ing.

An upper plate 105 for supplying balls to a take-in device (not shown), a lower plate 107 for storing balls that cannot be accommodated in the upper plate 105, and an ashtray are provided at a lower portion on the front side of the front frame 110. 106 etc. are installed. The game (variation display units 41a, 41b, 41) is provided on the front end face of the upper plate 105.
c), a stop switch 2a for stopping the corresponding variable display portions 41a, 41b, 41c, a stop switch 2a, 2b, 2c for stopping the corresponding variable display portions 41a, 41b, 41c; ), The bet number of balls is set to twice the number of unit balls (for example, 10).
2) is set. Below the upper plate 105, a flow path switch 10 for discharging the ball of the upper plate 105 to the lower plate 107 and a credit switch 9 for storing a prize ball as a credit ball are provided. .

The slot machine 10 configured as described above
In a state where the front cover member 120 is closed, a first protrusion 111a provided on the front frame 110 side is provided with a first groove portion provided on the front cover member 120 side, as shown in FIGS. 121a and the front cover member 1
A gap formed between the front frame 110 and the front frame 110 prevents an intruder (for example, a wire) from being inserted into the slot machine 100. That is, the first protrusion 111a and the first groove 121a constitute a first unauthorized intrusion prevention means. Further, when the front cover member 120 is closed, the front frame 11 is closed.
The second protruding portions 113A and 113B provided on the side of the front cover member 120 are respectively provided with the second protrusions 113A and 113B provided on the front cover member 120 side.
23A, 123B and the side walls 122a, 12
2f are arranged so as to cover the side portions of the driving means 42a and 42c of the display device 40, respectively, so as to prevent an unauthorized intruder from being inserted into each of the variable display portions 41a, 41b and 41c of the display device 40. Has become. That is, the second protrusion 1
13A, 113B and the second groove portions 123A, 123B constitute second unauthorized intrusion prevention means.

According to the slot machine 100 of this embodiment, as described above, the first illegal intrusion prevention means including the first protrusion 111a and the first groove 121a, and the second protrusions 113A and 113B and the first The provision of the second unauthorized entry prevention means including the two grooves 123A and 123B can prevent the display device 40 from being illegally operated by an unauthorized entry (for example, wire). Therefore, it is possible to prevent damage to the game store caused by an illegal act using an unauthorized intruder. In particular, the slot machine 1 of this embodiment
As shown in FIG. 5, the slot machine 100 is provided with not only the first unauthorized intrusion prevention means but also the second unauthorized intrusion prevention means. Even if an unauthorized intruder is inserted into the inside of the device, the inserted unauthorized intruder is obstructed by the second unauthorized intrusion prevention means, and each of the variable display portions 41a of the display device 40,
41b and 41c cannot be reached. Also, the first
A portion forming the protruding portion 111a and the second protruding portions 113A and 113B, a first groove portion 121a and a second groove portion 123;
A and 123B are both made of metal. Therefore, even if, for example, a heated wire or the like is used as an unauthorized intrusion, the unauthorized intrusion will be caused by the first protrusion 111a and the second protrusion 113A. , 113B, the first groove 121a and the second groove 123A, 123B.
The slot machine 1 for such unauthorized intruders
00 can be prevented from entering. Also, the first groove 121
The inner peripheral surface of a and the inner peripheral surfaces of the second groove portions 123A, 123B are covered with elastic materials 121b, 124, 124, respectively, and the respective protruding portions 111a, 113A, 113B are provided with the respective groove portions 121a, 123A, 123B. When the elastic members 121b, 124, and 124 are elastically deformed in the state where they are fitted into each other, the respective protruding portions and the respective groove portions come into close contact with each other, so that the respective protruding portions 111a, 113A, and 113B are provided.
Are fitted in the grooves 121a, 123A, 123B, and a gap is less likely to be formed between the grooves 121a, 123A, 123B and the protrusions 111a, 113A, 113B. Therefore, it becomes more difficult to insert an unauthorized intruder into the slot machine 100 from the gap formed between the front cover member 120 and the front frame 110.

The present invention is not limited to the slot machine 100 described in this embodiment, but can be applied to other types of slot machines using ball game media. Further, in this embodiment, the first groove 121a is provided on the front cover member 120 side, and the first protrusion 111a is provided on the front frame 110 side. However, the first protrusion is provided on the front cover member 120 side. Alternatively, a first groove may be provided on the front frame 110 side. Similarly, a second protrusion may be provided on the front cover member 120 side, and a second groove may be provided on the front frame 110 side. In this embodiment, when the front cover member 120 is closed, the driving units 42a and 42
The side walls 122a and 122f are arranged so as to cover the side portions of the variable display portions 41a, 41b and 41 of the display device 40.
Although an unauthorized intruder is prevented from being inserted into the display device 40c, a groove is provided at the position of the side walls 122a and 122f, and a protrusion that can be fitted into the groove is provided on the front frame 110 side. It is also possible to prevent an unauthorized intruder from being inserted into each of the variable display portions 41a, 41b, 41c.
Further, in this embodiment, the inner peripheral surface of the first groove 121a is coated with the elastic material 121b.
The outer peripheral surface of the first protrusion 111a may be covered with an elastic material. Similarly, the second protrusion 113A,
The outer peripheral surface of 113B may be coated with an elastic material. Further, the display device is not limited to the belt-type display device described in this embodiment, and may be, for example, a drum-type display device.

[0034]

According to the first aspect of the present invention, from the gap formed between the front cover member and the front frame when the front cover member is closed, from the gap formed between the front cover member and the front frame toward the display device inside the gaming machine. Since the intrusion prevention means for preventing the intrusion of the intruder is provided, it is possible to prevent the display device inside the gaming device from being illegally operated by the intruder. Therefore, it is possible to prevent damage to the game store caused by an illegal act using the illegal intruder.

According to the second aspect of the present invention, when the front cover member is closed, the first protrusion is fitted into the first groove, and the gap formed between the front cover member and the front frame. Therefore, it becomes impossible to insert an unauthorized intruder into the gaming device.

According to the third aspect of the present invention, since the portions forming the first projecting portion and the first groove portion are both made of metal, for example, it is assumed that a heated wire or the like is used as an unauthorized intruder. Also, the unauthorized intruder does not penetrate through the first protrusion and the first groove, so that even such an unauthorized intruder can be prevented from entering the inside of the gaming machine.

According to the fourth aspect of the present invention, at least one of the first groove and the first protrusion is coated with an elastic material, and the first protrusion is fitted in the first groove. Since the elastic member is elastically deformed so that the first protrusion and the first groove are in close contact with each other, the first groove and the first groove are in a state in which the first protrusion is fitted into the first groove.
It is difficult to form a gap between the protrusions. Therefore, it becomes more difficult to insert an unauthorized intruder into the inside of the gaming device from the gap formed between the front cover member and the front frame.

According to the fifth aspect of the present invention, when the front cover member is closed, the second protruding portion is fitted into the second groove, and an unauthorized intruder is inserted into each display portion of the display device. It becomes a difficult state. Further, the unauthorized intrusion prevention means may
In the case where not only the unauthorized intrusion prevention means but also the first unauthorized intrusion prevention means is included, it is assumed that the first unauthorized intrusion prevention means is breached and an unauthorized intruder is inserted inside the gaming machine. However, the inserted unauthorized intruder cannot reach each of the display units of the display device because the second unauthorized intrusion prevention means becomes an obstacle. Therefore, unauthorized operation of the display device can be reliably prevented.

According to the sixth aspect of the present invention, since the portions forming the second protruding portion and the second groove portion are both made of metal, for example, if a heated wire or the like is used as an unauthorized intruder, However, an unauthorized intruder does not penetrate through the second projecting portion and the second groove, so that it is possible to prevent such an unauthorized intruder from entering the display device.

According to the seventh aspect of the present invention, at least one of the second groove and the second protrusion is covered with an elastic material, and the second protrusion is fitted in the second groove. Since the second protrusion is in close contact with the second groove by elastically deforming the elastic member, the second groove and the second groove are in a state in which the second protrusion is fitted into the second groove.
It is difficult to form a gap between the protrusions. Therefore, it becomes more difficult to insert an unauthorized intruder into the display device.

[Brief description of the drawings]

FIG. 1 is a front view showing a slot machine exemplified as a gaming machine according to the present invention.

FIG. 2 is a perspective view showing the slot machine of FIG. 1, showing a state in which a front cover member is opened.

FIG. 3 is a cross-sectional view of a portion corresponding to the view taken along the line AA of FIG. 1;

FIG. 4 is a cross-sectional view of a portion corresponding to a view taken along arrow BB of FIG. 1;

FIG. 5 is a cross-sectional view showing the positional relationship between the first unauthorized intrusion prevention means shown in FIG. 3 and the second unauthorized intrusion prevention means shown in FIG.

[Explanation of symbols]

4a, 4b, 4c Window 40 Display 41a, 41b, 41c Variable display 100 Slot machine (game machine) 110 Front frame 111 Front frame side unauthorized intrusion prevention member 111a First protrusion (first unauthorized intrusion prevention means) 113A, 113B Second protrusion (second unauthorized intrusion prevention means) 120 Front cover member 121 Cover side unauthorized intrusion prevention member 121a First groove (first unauthorized intrusion prevention means) 121b Elastic material 122a, 122b, 122c, 122d , 122e,
122f Side wall 123A, 123B Second groove (second illegal intrusion prevention means)

Claims (7)

[Claims] 1. A display device capable of variably displaying a plurality of types of identification information by performing a switch operation by betting a ball, a front frame to which the display device is attached, and a state in which the front frame can be freely opened and closed. And a front cover member that covers the display device, when the stop result of the variable display is a predetermined result mode, a required number of In a gaming device capable of providing a prize ball, in a state where the front cover member is closed, a gap formed between the front cover member and the front frame extends in the direction of the display device inside the gaming device. A gaming device comprising an unauthorized intrusion prevention means for preventing an unauthorized intruder from being inserted. 2. The front cover according to claim 1, wherein said unauthorized intrusion prevention means comprises: a first groove provided on a back side of said front cover member along an edge of said front cover member; The gaming machine according to claim 1, further comprising a first unauthorized intrusion prevention means comprising: a first protruding portion that fits into the first groove when the member is closed. 3. The gaming machine according to claim 2, wherein both the first protrusion and the portion forming the first groove are made of metal. 4. At least one of the first groove and the first protrusion is coated with an elastic material, and the elastic material is fitted in a state where the first protrusion is fitted in the first groove. Is elastically deformed, so that the first
The gaming device according to claim 2, wherein the protrusion and the first groove are in close contact with each other. 5. The display device includes a plurality of display sections on which the plurality of types of identification information are displayed, and wherein the unauthorized intrusion prevention means is provided in a state protruding forward from between the adjacent display sections. A second illegal intrusion prevention means, comprising: a second protrusion, and a second groove provided on the back surface side of the front cover member and into which the second protrusion is fitted when the front cover member is closed. The gaming device according to any one of claims 1 to 4, comprising: 6. The gaming machine according to claim 5, wherein both the second protrusion and the portion forming the second groove are made of metal. 7. At least one of the second groove and the second protrusion is coated with an elastic material. When the second protrusion is fitted in the second groove, the elastic material is provided. Is elastically deformed, whereby the second
The gaming device according to claim 5, wherein the protrusion and the second groove are in close contact with each other.