JP3286280B2 - Key mechanism of pachinko machine front plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key mechanism of a front plate of a pachinko machine for fixing a front plate having a structure that can be opened and closed to a front frame to the front frame.

[0002]

2. Description of the Related Art In a pachinko machine 1, as shown in FIG. 9A, a front plate 4 is disposed below a metal frame 3, and the metal frame 3 and the front plate 4 It is mounted so that it can be opened and closed like a door. In a state in which the metal frame 3 and the front plate 4 are closed, the rotation free end side of the metal frame 3 is as shown in FIG.
As shown in (1), the front plate 4 is supported by the free rotation end side. Here, the figure number Y in FIG. 9 (B) is a game board. A ball tray 4x for storing a prize ball is mounted on the surface of the front plate 4, and a launch window (not shown) through which a prize ball passes is formed at the position of the ball tray 4x. Further, on the back surface of the front plate 4, as shown in FIG.
A prize ball supply mechanism 4m is mounted at a position covering the launch window. The prize ball supply mechanism 4m is a member that guides the prize ball in the ball tray 4x from the launch window to the launching device (not shown) of the pachinko machine 1, and when the front plate 4 is opened from the front frame 2, Automatically close the award ball passage. Therefore, when the front plate 4 is opened, the prize balls in the ball tray do not fall from the launch window.

[0003] A key composed of a lock base plate 4d and a slide claw (only a claw body is shown in the figure) beside a prize ball supply mechanism 4m on the free rotation end side of the back surface of the front plate 4. A mechanism is attached, and an engagement piece 2k on which the claw main body 4s of the slide claw is hooked is disposed below the free end of the front frame 2. The slide claw has a claw body 4s at its lower end.
Are formed, and the front plate 4 is fixed to the front frame 2 by hooking the claw body 4s on the engagement piece 2k from below.

[0004]

As described above, the prize ball supply mechanism 4m is attached to the front plate 4, and when the front plate 4 is opened from the front frame 2, the prize ball supply mechanism 4m is attached to the ball. Prevents prize balls from falling in the saucer. However, depending on the type of the pachinko machine, there is a type in which the prize ball supply mechanism 4m is provided on the main body side of the pachinko machine. In such a type of pachinko machine, it is not necessary to provide the prize ball supply mechanism 4m on the front plate 4, so that when the front plate 4 is opened from the front frame 2, the firing window must be closed by another means. There is a problem that it does not. Also,
The key mechanism of the front plate 4 fixes the front plate 4 to the front frame 2 by hooking a single claw body 4 s formed at the lower end of the slide claw on the engaging piece 2 k of the front frame 2. That is, the free end of the front plate 4 is connected to the front frame 2 at one position at the lower end of the front plate. For this reason, for example, when the player intentionally applies a force in the direction of pushing down to the ball tray 4x of the front plate 4, as shown in FIG. It may be twisted forward with the 4s and the engagement piece 2k as a fulcrum. When the front plate 4 is twisted forward, the metal frame 3 supported by the front plate 4 is also twisted forward, and the dimension between the glass surface of the metal frame 3 and the game board Y changes, thereby causing a game. The flow of the game ball on the board of the board Y changes. As a result, problems such as an unreasonable increase in the probability of winning a game ball and a tendency for the game ball to be clogged occur.

[0005] The invention described in claims 1 and 2 is:
By enabling the opening and closing of the front window of the front panel directly by the key mechanism, even if the front panel does not have a prize ball supply mechanism, the opening of the front panel can be reliably closed when opening the front panel. Its purpose is to An object of the invention described in claim 3 is to improve the key mechanism so that the front plate is hardly twisted.

[0006]

The above object is achieved by a key mechanism for a front plate of a pachinko machine according to the present invention. According to the present invention, the front plate is closed and fixed to the front frame by sliding the slide claw to the engagement position with respect to the lock base plate fixed to the front plate and hooking the engagement tab of the front frame. Can be. Further, if the slide claw is slid to the release position with respect to the lock base plate and the slide claw is disengaged from the engagement piece of the front frame, the front plate can be opened. When the front plate is opened, the holding plate attached to the slide claw closes the emission window of the front plate, so that the prize ball in the ball tray does not fall from the emission window. Further, the slide claw is forcibly moved to the release position when an external force in the direction of the release position is applied to the slide claw by the action of the slide force applying member, and the slide claw stops halfway between the engagement position and the release position. Never do. For this reason, a trouble that the front panel is opened without closing the launch window does not occur. When an external force is applied to the slide claw in the direction of the engagement position, the slide claw is forcibly moved to the engagement position, and the slide claw is hung on the engagement piece of the front frame. As described above, according to the present invention, since the opening window of the front plate can be opened and closed by the slide claw pressing plate constituting the key mechanism, even if the front plate does not have the prize ball supply mechanism, the front plate is opened. In this case, the launch window can be securely closed.

[0007] The above-mentioned problem is solved by the key mechanism of the front plate of the pachinko machine according to the second aspect. According to the present invention, since the sliding force applying member can be manufactured by the torsion coil spring, the cost of the sliding force applying member can be reduced.

[0008] Another object described above is solved by a key mechanism of a front plate of a pachinko machine according to claim 3. According to the present invention, the key mechanism has a structure in which the front plate is fixed to the front frame by hooking a plurality of claw bodies formed in the vertical direction of the slide claw respectively to the plurality of engagement pieces of the front frame. That is,
The free rotation end side of the front plate is connected to the front frame at a plurality of vertical positions. For this reason, even if the player intentionally applies a force in the direction of pressing down on the ball tray of the front plate, the front plate is unlikely to be twisted forward by the operation of the key mechanism, and the metal frame supported by the front plate. Is also reduced. Therefore, the dimension between the glass surface of the metal frame and the board surface of the game board hardly changes, and the winning probability of the game ball due to the change in the flow of the game ball becomes unduly high, or the game ball is easily clogged. No problem such as becoming.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG.
The key mechanism of the front plate of the pachinko machine according to the first embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a front view (FIG. A) and a side view (B) showing an open state of the key mechanism.
FIG. 2 is a front view (A), a side view (B), and a detailed view (C) of the key mechanism in a closed state. 3 is a front view (A) and a side view (B) of a slide claw constituting the key mechanism. FIG. 4 is a front view (A) of a lock base plate constituting the key mechanism.
Fig.) And a side view (Fig. B). FIG. 5 is a perspective view showing a state where the metal frame and the front plate of the pachinko machine are opened.

As shown in FIG. 5, the pachinko machine 10 has a front plate 14 disposed below a metal frame 13, and the metal frame 13 and the front plate 14 are opened and closed like a door with respect to the front frame 12. Installed as possible. A ball tray (not shown) for storing a prize ball is attached to the surface of the front plate 14, and the prize ball is guided to a firing device (not shown) of the pachinko machine 10 at the position of the ball tray. Launch window 14m
Are formed. A lock base plate 20 and a slide claw 3, which are components of a key mechanism, are provided on the back of the front plate 14 at the freely rotating end side.
The front plate 14 is fixed to the front frame 12 by hooking the slide claw 30 on an engagement piece 12 k fixed to the lower right side surface of the front frame 12.

Next, the individual structures of the lock base plate 20 and the slide claw 30 will be described with reference to FIGS. The slide claw 30 is a claw-shaped plate that slides up and down with respect to the lock base plate 20 described later, and has a lever 31 formed at an upper portion thereof as shown in FIG. A substantially U-shaped groove 32 is formed below the lever 31 to receive the engagement piece 12k (see FIGS. 1, 2 and 5) of the front frame 12. Further, between the lever 31 and the groove 32, an inclined surface 33 with which the engaging piece 12k of the front frame 12 abuts in the process of closing the front plate 14 is formed. Further, the groove 32
A claw main body 34 that is hung on the engagement piece 12k is formed at the lower part of.

At the center of the groove 32, a rectangular support 32s is fixed at right angles to the plate surface of the slide claw 30, and a holding plate 43, which is a flat L-shaped thin plate, is attached to the support 32s. I have. The holding plate 43 is the front plate 14
Opening window 1 of front plate 14 when is opened from front frame 12
It is a plate for closing 4 m, and is installed in close contact with the back surface of the front plate 14. An elongated hole 35 is formed vertically above the inclined surface 33 and below the claw body 34, and a stopper 36 for receiving one end of a spring 41 described below below the elongated hole 35 located further below. Are formed.

The lock base plate 20 is provided with the slide claw 30
Is a plate having an L-shaped cross-section that supports the
It is composed of a fixed plate 21a and a guide plate 21b. The fixed plate 21a is a plate fixed to the free end side of the back surface of the front plate 14, and has rivet holes 22 formed at two upper and lower portions as shown in FIG. Further, a stopper 26 for receiving the other end of the spring 41 is formed beside the rivet hole 22 located on the lower side.

The guide plate 21b of the lock base plate 20 is a plate for slidably supporting the slide claw 30.
As shown in (B), the lock base plate 20 and the engagement pieces 12 of the front frame 12 extend from the center to the upper part of the guide plate 21b.
A concave portion 24 for avoiding interference with k is formed.
The guide plate 21b has an engagement pin 25 that is inserted into the elongated hole 35 of the slide claw 30 above and below the recess 24.
Has been fixed.

Next, the operation of the key mechanism of the front plate 14 will be described with reference to FIGS. As shown in FIGS. 1 and 2, the slide claw 30 and the lock base plate 20 that constitute the key mechanism allow the engagement pin 25 of the lock base plate 20 to pass through the elongated hole 35 of the slide claw 30. Are connected by With this structure, the slide claw 30 can be slid up and down relative to the lock base plate 20 by a distance substantially equal to the length of the long hole 35.

A spring 41 is mounted between the stopper 36 of the slide claw 30 and the stopper 26 of the lock base plate 20. As shown in FIGS. 1C and 2C, the spring 41 is a flat L-shaped torsion coil spring, and moves the slide claw 30 to the upper limit position (see FIG. 2) or the lower limit position (FIG. 1). (See reference). That is, when the slide claw 30 at the upper limit position is pressed down against the spring force, the spring 41 is deformed and acts in a direction to push down the slide claw 30, and the slide claw 30 moves to the lower limit position by the spring force. Held in that position. Conversely, when the slide claw 30 at the lower limit position is pushed up against the spring force, the spring 41 is deformed and acts in a direction to push up the slide claw 30, and the slide claw 30 moves to the upper limit position by the spring force. Held in that position. That is, the spring 41 corresponds to the sliding force applying member of the present invention.

At the upper limit position, the claw body 34 of the slide claw 30
Is hung on the engagement piece 12k of the front frame 12, so that the front plate 14
Is fixed to the table frame 12. That is, the upper limit position corresponds to the engagement position of the present invention. In the state where the slide claw 30 is at the upper limit position, as shown in FIG. 2A, the holding plate 43 is located above the emission window 14m of the front plate 14, and the emission window 14m is opened. It is. For this reason, the front plate 1
In the closed state, the winning ball in the ball tray of the front plate 14 is guided from the launch window 14m to the launching device of the pachinko machine 10 by a winning ball supply mechanism (not shown).

The lever 3 of the slide claw 30 at the upper limit position
1 is pressed down against the force of the spring 41, the spring 41 is deformed and the spring 41
Acts in the direction of pushing down. Thereby, the slide claw 30 moves to the lower limit position by the spring force and is held at that position. When the slide claw 30 is lowered, the front frame 12
The claw main body 34 of the slide claw 30 is disengaged from the engaging piece 12k of the above, and the front plate 14 can be opened to the front frame 12. In addition, while the inclined surface 33 of the slide claw 30 descends,
Since the second engagement piece 12k is pushed out from the groove 32, the free rotation end side of the front plate 14 is separated from the front frame 12 (see FIG. 1B).

Further, when the slide claw 30 is held at the lower limit position, as shown in FIG. 1A, the pressing plate 43 closes the emission window 14m of the front plate 14. For this reason, even if the front plate 14 is opened, the prize balls in the ball tray will not fall out of the launch window 14m. That is, the lower limit position corresponds to the release position of the present invention. After the front plate 14 is opened in this way, when the front plate 14 is to be closed next, the free end of the front plate 14 is pressed against the front frame 12. Thereby, the engagement piece 12k of the front frame 12 presses the inclined surface 33 of the slide claw 30 horizontally (see FIG. 1B).

Then, the horizontal pressing force of the engagement piece 12k,
That is, a force for closing the front plate 14 acts in a direction to push up the slide claw 30 via the inclined surface 33. When the slide claw 30 is pushed up against the spring force,
The spring 41 is deformed and acts in a direction to push up the slide claw 30. Thereby, the slide claw 30 moves to the upper limit position by the spring force and is held at that position. When the slide claw 30 is held at the upper limit position, as shown in FIG. 2, the claw body 34 of the slide claw 30 is hooked on the engagement piece 12 k of the front frame 12, and the front plate 14 is fixed to the front frame 12. Is done.

As described above, according to the present embodiment, since the opening window 14m of the front plate 14 can be opened and closed by the key mechanism, even if the front plate 14 does not have the prize ball supply mechanism, the front plate can be opened and closed. The opening window 14m can be securely closed when the opening 14 is opened. When an external force in the opening direction (downward) is applied to the slide claw 30 by the action of the slide force applying member (spring 41), the slide claw 30 is forcibly moved to the lower limit position. Does not stop halfway between the upper and lower positions. For this reason, a trouble that the front plate 14 is opened without closing the outlet window 14m does not occur. Further, since the sliding force applying member can be manufactured by the torsion coil spring, the cost of the sliding force applying member can be reduced.

(Second Embodiment) Next, FIGS.
The key mechanism of the front plate of the pachinko machine according to the second embodiment of the present invention will be described based on the above. In the present embodiment, the slide claw described in the first embodiment is improved, and a claw main body is formed at two upper and lower portions. The other structure is the key of the front plate according to the first embodiment. It is almost the same as the mechanism. For this reason, the description of portions having the same structure as the key mechanism of the front plate according to the first embodiment will be omitted, and portions having different structures will be mainly described. Here, FIG. 6A is a side view showing an open state of the key mechanism, and FIG. 6B is a side view showing a closed state of the key mechanism. FIG.
(A) is a side view of a slide claw constituting the key mechanism, FIG. 7 (B) is a side view of a lock base plate constituting the key mechanism, and FIG. 8 is opening a metal frame and a front plate of the pachinko machine. It is a perspective view showing the state which performed.

The slide claw 70 is a lock base plate 60 described later.
7 is a claw-shaped plate that slides up and down with respect to FIG.
As shown in (A), a lever 71 is formed on the upper part. Below the lever 71, a substantially U-shaped upper groove 72 for accommodating the upper engagement piece 52e (see FIG. 8) of the front frame 12 is formed. Between the lever 71 and the upper groove 72, there is formed an upper inclined surface 73 with which the upper engaging piece 52e of the front frame 12 abuts while the front plate 14 is closed. Further, an upper claw main body 74 which is hung from below on the upper engagement piece 52e is formed below the upper groove 72.

On the lower side of the upper claw body 74, a front plate 14 is provided.
8k (see FIG. 8).
The lower engaging surface 52 a of the front frame 12 is formed below the lower inclined surface 76.
Is formed in a substantially U-shaped lower groove 75 in which is stored.
The lower engaging piece 52 is provided below the lower groove 75.
A lower claw body 77 that is hung from below on k is formed. At the position opposite to the upper claw main body 74, a holding plate 78 that closes the firing window 14m when the front plate 14 is opened is attached to the slide claw 70. Further, an elongated hole 79 is formed vertically above the upper groove 72 and below the lower claw body 77, and further below the elongated hole 79 located on the lower side, the twist described in the first embodiment is formed. One end of the coil spring is connected (not shown).

The lock base plate 60 is connected to the slide pawl 70
Is a plate having an L-shaped cross-section that supports the
The front plate 14 is fixed to the rear free end side. The lock base plate 60 includes a fixed plate 61a fixed to the front plate 14 and a guide plate 61b for guiding the slide claw 70, and the other end of the torsion coil spring is connected to a predetermined position of the fixed plate 61a. (Not shown). A recess 64 is formed in the guide plate 61b of the lock base plate 60 so that the lock base plate 60 does not interfere with the upper engagement piece 52e and the lower engagement piece 52k of the front frame 12. Recess 64
An engaging pin 65 that is inserted into the elongated hole 79 of the slide claw 70 is fixed at a predetermined upper and lower position.

Next, the operation of the key mechanism of the front plate 14 will be described with reference to FIGS. The slide claw 70 and the lock base plate 60 constituting the key mechanism are shown in FIG.
As shown in (B), the engagement is achieved by passing the engagement pin 65 of the lock base plate 60 through the elongated hole 79 of the slide claw 70. Furthermore, the slide claw 70 and the lock base plate 6
0, the torsion coil spring (not shown) is mounted, and the slide claw 70 is moved to the upper limit position (see FIG. 6B) or the lower limit position (FIG. 6A) by the function of the torsion coil spring. ) See).

At the upper limit position, the upper pawl main body 74 and the lower pawl main body 77 of the slide pawl 70 are hung on the upper engaging piece 52e and the lower engaging piece 52k of the front frame 12, respectively. 12 fixed. In a state where the slide claw 70 is at the upper limit position, the holding plate 78 is located above the emission window 14m of the front plate 14, and the emission window 1
4m is opened.

The lever 7 of the slide claw 70 at the upper limit position
When 1 is pressed down against the force of the torsion coil spring, the torsion coil spring is deformed and acts in a direction to push down the slide claw 70. Thus, as shown in FIG. 6A, the slide claw 70 moves to the lower limit position by the spring force and is held at that position. When the slide claw 70 is lowered, the upper engaging piece 52e and the lower engaging piece 5 of the front frame 12 are lowered.
The upper claw body 74 and the lower claw body 77 of the slide claw 70 come off from 2k, respectively, and the front plate 14 can be opened to the front frame 12.

When the slide claw 70 descends, the lower inclined surface 76 engages the lower engagement piece 52k of the front frame 12 with the lower groove 75.
From the upper engaging piece 52e.
Is pushed out from the upper groove 72, the free end of the front plate 14 is separated from the front frame 12. Further, by holding the slide claw 70 at the lower limit position, as shown in FIG.
The holding plate 43 closes the emission window 14 m of the front plate 14. For this reason, even if the front plate 14 is opened, the prize balls in the ball receiving tray remain
It does not spill from 4m.

After opening the front plate 14 in this manner,
Next, when closing the front plate 14, the free end of the front plate 14 is pressed against the front frame 12. Thereby, the upper engaging piece 52e and the lower engaging piece 52k of the front frame 12 are respectively connected to the upper inclined surface 73 and the lower inclined surface 76 of the slide claw 70.
And horizontally. The horizontal pressing force between the upper engagement piece 52e and the lower engagement piece 52k, that is, the force for closing the front plate 14 is applied to the slide claw 70 via the upper inclined surface 73 and the lower inclined surface 76. Acts in the direction of pushing up.

When the slide claw 70 is pushed up against the spring force of the torsion coil spring, the torsion coil spring is deformed and acts in a direction to push up the slide claw 70. Thereby, the slide claw 70 moves to the upper limit position by the spring force and is held at that position. When the slide claw 70 is held at the upper limit position, as shown in FIG. 6B, the upper claw body 74 and the lower claw body 77 of the slide claw 70 are respectively connected to the upper engagement piece 52e of the front frame 12 and the lower claw body. The front plate 14 is fixed to the front frame 12 by being hung on the engagement piece 52k.

As described above, according to the key mechanism of the front plate according to the present embodiment, the upper claw body 74 and the lower claw body 77 formed on the slide claw 70 are connected to the upper engagement piece 52e of the front frame 12 and the lower claw. By hanging each piece 52k, the front plate 1
4 is fixed to the table frame 12. That is, the free rotation end of the front plate 14 is connected to the front frame 12 at two upper and lower positions. For this reason, even if the player intentionally applies a force in the direction of pushing down the ball tray of the front plate 14, the front plate 14 is unlikely to be twisted forward, and the metal frame 13 supported by the front plate 14 Torsion is also reduced. Therefore, the dimension between the glass surface of the metal frame 13 and the board surface of the game board hardly changes, and the probability of winning the game ball due to the change in the flow of the game ball becomes unduly high, or the game ball is clogged. No problems such as easiness occur.

In this embodiment, the slide claw 70 is formed with two claw bodies 74 and 77, and the front frame 12 is provided with the engagement pieces 52e and 52k at two places. The number of the main body and the engagement pieces may be further increased.

[0034]

According to the present invention, the opening window of the front plate can be opened and closed by the key mechanism. Therefore, even if the front plate does not have the prize ball supply mechanism, the opening window is opened when the front plate is opened. Can be closed securely. Further, according to the present invention, since the free end side of the front plate can be connected to the front frame at a plurality of locations, the front plate is less likely to be twisted forward, and the metal frame supported by the front plate. Is also reduced.

[Brief description of the drawings]

FIG. 1 is a front view (FIG. 1A), a side view (FIG. 1B), and a detailed view of a main part (FIG. 1C) showing an open state of a key mechanism of a front plate of a pachinko machine according to a first embodiment of the present invention. It is.

FIG. 2 is a front view (FIG. 2A), a side view (FIG. 2B), and a detailed view of a main part (FIG. 2C) showing the closed state of the key mechanism of the front plate of the pachinko machine according to the first embodiment of the present invention. It is.

FIG. 3 is a front view (A) and a side view (B) of a slide claw in a key mechanism of a front plate of the pachinko machine according to the first embodiment of the present invention.

FIG. 4 is a front view (A) and a side view (B) of a lock base plate in the key mechanism of the front plate of the pachinko machine according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing the pachinko machine according to the first embodiment of the present invention in a state where a metal frame and a front plate are opened.

FIG. 6 is a side view showing an open state (FIG. A) and a side view showing a closed state of a key mechanism of a front plate of a pachinko machine according to a second embodiment of the present invention (FIG. B).

FIG. 7 is a side view of a slide claw in a key mechanism of a front plate of a pachinko machine according to a second embodiment of the present invention (FIG. A), and a side view of a lock base plate (FIG. B).

FIG. 8 is a perspective view showing a state where a metal frame and a front plate of a pachinko machine according to a second embodiment of the present invention are opened.

FIG. 9 is an overall perspective view of a conventional pachinko machine (FIG. A), a cross-sectional view of a B portion in FIG. A (FIG. B), and a cross-sectional view of a B portion showing a state where the front plate is twisted.

FIG. 10 is a perspective view showing a state where a metal frame and a front plate of a conventional pachinko machine are opened.

[Explanation of symbols]

 12 Front frame 12k Engagement piece 13 Metal frame 14 Front plate 14m Ejector window 20 Lock base plate 30 Slide claw 41 Spring (sliding force applying member) 43 Holding plate 52e Upper engagement piece 52k Lower engagement piece 60 Lock base plate 70 Slide claw 74 Upper claw body 77 Lower claw body

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A63F 7/02 327 E05B 61/00

Claims (3)

(57) [Claims] 1. A key mechanism for a front plate of a pachinko machine for fixing a front plate having a structure that can be opened and closed with respect to the front frame, comprising: a lock base plate fixed to the front plate; A slide claw that is slidably mounted on the slide claw and slides between an engagement position and a release position, and is attached to the slide claw, and the slide claw is held at the release position. A presser plate for closing an ejection opening window formed on the front plate, and when an external force is applied to the slide claw in an engagement position direction or a release position direction, the slide claw is forcibly moved in the direction of the external force. A pachinko machine comprising: a sliding force applying member to be moved; and an engagement piece installed on the front frame and engaged with the slide claw when the slide claw slides to an engagement position. Board Mechanism. 2. The key mechanism for a front plate of a pachinko machine according to claim 1, wherein the sliding force applying member is a torsion coil spring having one end connected to a lock base plate and the other end connected to a slide claw. A key mechanism on the front panel of a pachinko machine. 3. A key mechanism for a front plate of a pachinko machine for fixing a front plate having a structure that can be opened and closed with respect to the front frame to a lock base plate fixed to the front plate, and a lock base plate fixed to the front plate. A slide claw having a plurality of claw bodies in the up and down direction while being moved between an engagement position and a release position with respect to the slide claw; A sliding force applying member for forcibly moving the slide claw in the direction of the external force when an external force is applied in a position direction; and a plurality of slide force applying members corresponding to respective claw bodies of the slide claw at predetermined positions of the front frame. A key mechanism for a front plate of a pachinko machine, comprising: a plurality of engaging pieces, each of which is installed, and each of which is engaged when the sliding claw slides to an engagement position.