JP2004020576A - Opening and closing lid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an opening and closing lid that obtains a tall music score stand even if the depth of a case is short. <P>SOLUTION: The opening and closing lid is provided with the case one long side of which is an operation side and the other long side of which is a back side, a first opening and closing lid and a second opening and closing lid that is formed by dividing the opening face of the case into two so that the operation side is shorter and the back side is longer to open and close it regarding a short direction, a hinge coupling these first and second opening and closing lids with rotary motion, an arm shifting the first opening and closing lid along a circular arc, a stay shifting a position of a supporting axis bearing the second opening and closing lid with the rotary motion, linked to the shift in the circular arc of the first opening and closing lid, a slide sliding a position of the supporting axis to the side of the rotary motion of the second opening and closing lid in a state where the direction of a board of the second opening and closing lid is almost parallel with the direction of gravity, and a spring giving unilateral and elastic rotary biasing force to the stay. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an opening / closing lid suitable for use in, for example, a keyboard instrument, and particularly to a novel structure that can be used as a music stand and a music stand with the opening / closing lid regardless of a short depth dimension.
[0002]
[Prior art]
2. Description of the Related Art Various types of keyboard instruments have been proposed as open / close lids that cover an arrangement surface of keyboards. As is well known, one long side of a rectangular case is an operation side, and the other long side is a back side. A keyboard is arranged along the long side of the operation side, and an opening / closing lid is provided on an arrangement surface of the keyboard, so that the arrangement surface of the keyboard can be opened and closed.
The example shown in FIG. 9 shows an example of a structure in which the keyboard arrangement surface of the case 1 is opened and closed by a slide-type opening / closing lid 2. In the example shown in FIG. 10, a case is shown in which the double-folded opening / closing lid 3 is flipped up to open and close the keyboard arrangement surface.
[0003]
[Problems to be solved by the invention]
When the slide-type opening / closing lid 2 shown in FIG. 9 is used, a music stand and a music rest must be prepared separately from the opening / closing lid 2, so that there is a disadvantage that the number of parts increases and the cost increases.
Further, in the example shown in FIG. 10, the opening / closing lid 3 can be used both as a music stand and a music stand. However, since the opening / closing lid 3 of this structure is divided into two at a position which is about 1/2 of the depth of the lid, the height dimension tends to be insufficient for use as a music stand. In particular, if the depth of the case 1 is shortened with the downsizing of the musical instrument, the depth of the opening / closing lid 3 must be shortened accordingly, so that the height of the music stand becomes insufficient.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to propose a novel structure of an opening / closing lid in which when the opening / closing lid is used also as a music stand and a music stand, the height of the music stand can be made as high as possible.
[0005]
[Means for Solving the Problems]
According to the first aspect of the present invention, a case in which the opening surface has a substantially rectangular shape, one long side is the operation side, and the other long side is the back side, and the opening surface of the case is operated in the short side direction. The first opening / closing lid and the second opening / closing lid which have a short side and a long rear side and are divided into two to open and close the opening surface of the case, and rotate between the first opening / closing lid and the second opening / closing lid. A hinge that is movably connected and a free end that extends to the hinge side in the short side direction of the first opening / closing lid are rotatably supported in the case, support the first opening / closing lid, and mount the first opening / closing lid. An arm that moves along a predetermined arc and changes the angle of the plate surface of the plate material constituting the first opening / closing lid in accordance with each movement position to move to a position for closing the opening surface on the operation side of the case and a position for opening the case. And a support for rotatably supporting the second opening / closing lid at a predetermined position in the short side direction of the second opening / closing lid. A stay for moving the position of the shaft in conjunction with the arc movement of the first opening / closing lid, and supporting the second opening / closing lid according to its own weight in a state in which the plate surface direction is substantially parallel to the direction of gravity. A slider that slides the shaft position toward the rotation play end of the second opening / closing lid, and a state in which a unidirectional elastic rotation biasing force is applied to the stay, and the slide direction of the slider matches the rotation direction of the support shaft. And a spring for returning the position of the support shaft to a predetermined position.
[0006]
According to a second aspect of the present invention, in the opening / closing lid according to the first aspect, the stay and the second opening / closing lid are engaged with each other in a state where the position of the support shaft is slid toward the rotating free end side of the second opening / closing lid. (2) An opening / closing lid having a structure to which an engagement means for preventing the first opening / closing lid and the second opening / closing lid from moving in the closing direction due to an external force acting on the opening / closing lid in the closing direction is proposed.
According to a third aspect of the present invention, in the shift of the opening / closing lid according to the first or second aspect, engagement with the arm starts at a position where the first opening / closing lid approaches the closing position, and the first opening / closing lid and the second opening / closing lid. The present invention proposes an opening / closing lid having a structure in which a buffer means for reducing the moving speed of the first opening / closing lid and the second opening / closing lid by receiving a biasing force toward the closed position generated by the gravity applied to the opening / closing lid is added.
[0007]
According to a fourth aspect of the present invention, in any one of the first to third opening / closing lids, a biasing force is applied to the spring in a state where the first opening / closing lid moves toward the closed position to the arm, and the arm is provided with a biasing force. (1) To propose an opening / closing lid having a structure in which energy storage means for storing kinetic energy for moving the opening / closing lid in an opening direction is added.
According to a fifth aspect of the present invention, in any one of the opening / closing lids according to the first to fourth aspects, a keyboard instrument is mounted inside the case, and the first opening / closing lid and the second opening / closing lid are in a closed state and the keyboard of the keyboard instrument. It proposes an opening / closing cover which covers the arrangement surface and in the open state, the first opening / closing cover acts as a music rest and the second opening / closing cover acts as a music stand.
According to a sixth aspect of the present invention, in the opening / closing lid according to the fifth aspect, a movable plate supported by the second opening / closing lid so as to be able to freely enter and exit from a free play end surface of the second opening / closing lid, and the movable plate having the stay There is proposed an opening / closing lid having a structure provided with a connecting means for connecting the supporting shaft supported by the supporting shaft.
[0008]
According to the structure of the lid proposed by the action <br/> claim 1 of the present invention, the lid is divided into two parts with respect to the shorter side direction of the case, a first lid that is divided into two, the second lid is each other The first opening / closing lid is rotatably supported by an arm having a free end extended to the hinge side and pivotally supported in the case, and the first opening / closing lid moves in an arc by the arm. The hinge portion connecting the first opening / closing lid and the second opening / closing lid moves in a direction to enter the case according to the rotation of the arm.
As a result, in the opening / closing lid of the present invention, in contrast to the case of the two-folded opening / closing lid 3 shown in FIG. In particular, in the present invention, the first opening / closing lid located on the operation side of the two divided lids is selected to be shorter than the depth dimension of the second opening / closing lid located on the back side. Can be widely adopted. Therefore, when the opening / closing lid according to the present invention is used as an opening / closing lid for a keyboard instrument, a tall music stand can be obtained by the second opening / closing lid. In addition, a short music rest can be obtained on the entire surface of the music stand by the first opening / closing lid.
[0009]
Furthermore, according to the opening / closing lid proposed in claim 2 of the present invention, even if an external force acting in the closing direction is applied to the first opening / closing lid and the second opening / closing lid in the open state, the external force is received by the engaging means. The opening / closing lid does not close. Therefore, even if an external force in the closing direction is applied to the opening / closing lid during the performance, the opening / closing lid according to the present invention does not inadvertently close the opening / closing lid, and the player's hand is pinched by the opening / closing lid. Accidents can be avoided.
Further, according to the opening / closing lid proposed in claim 3 of the present invention, when returning the first opening / closing lid and the second opening / closing lid to the closed position, the arm for supporting the first opening / closing lid rotatably includes the buffer means. Therefore, the speed of approaching the closing position is reduced, so that the lid can be safely closed without pinching a finger or the like.
[0010]
Further, according to the opening / closing lid proposed in claim 4 of the present invention, when the lid is closed, the biasing force in the closing direction generated by the weight of the first opening / closing lid and the second opening / closing lid is stored in the energy storage means. You can use this energy to open the lightly.
Further, in claim 5 of the present invention, the opening / closing lid proposed in the present invention is applied to a keyboard instrument, and in claim 6, a movable plate of a second opening / closing lid is mounted, and the movable plate is released from the second opening / closing lid. Since the user slides upward in a state in which the music is standing, a tall music stand can be obtained.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows the structure of the main part of the opening / closing lid according to the present invention. In FIG. 1, reference numeral 1 denotes a case whose opening surface is substantially rectangular. 1A indicates one long side, and the long side 1A is the operation side and the other long side 1B is the back side.
In the present invention, a rectangular opening surface of the case 1 is divided into two parts by a first opening / closing lid 11 and a second opening / closing lid 12 in the short side direction, and is opened and closed.
The feature of the present invention is that the depth of the first opening / closing lid 11 for opening and closing the opening surface on the side close to the long side 1A on the operation side is selected to be shorter than the depth of the second opening / closing lid 12. The first opening / closing lid 11 and the second opening / closing lid 12 are rotatably connected by a hinge 13 (see FIGS. 2 to 6), and the first opening / closing lid 11 is extended outwardly from a connection point of the hinge 13. The free end of the arm 14 is rotatably supported by the case 1. Therefore, the free play end of the arm 14 and the free play end of the first opening / closing cover 11 coincide with each other, and the hinge connection portion between the first open / close cover 11 and the second open / close cover 12 is connected to the free play end of the arm 14 and the shaft. It is arranged between the fulcrum position. With this structure, the position of the hinge 13 connecting the first opening / closing lid 11 and the second opening / closing lid 12 moves along the arc A shown in FIG. 2, and during this movement, the first opening / closing lid 11 and the second opening / closing lid 12 are moved. Rotate in the direction in which they face each other.
[0012]
That is, when the first opening / closing lid 11 and the second opening / closing lid 12 close the opening surface of the case 1 (see FIG. 2), their plate surfaces are flush as shown in FIG. . By applying an upward force to the rotating play end 11A of the first opening / closing lid 11, the hinge 13 connecting the first opening / closing lid 11 and the second opening / closing lid 12 follows the arc A as shown in FIG. It passes through the positions 2), 3) and 4). As the position of the hinge 13 approaches the rear side 1B of the case 1, the plate surfaces (upper surfaces) of the first opening / closing lid 11 and the second opening / closing lid 12 change their postures so as to face each other. As shown in FIG. 4, the surfaces of the open / close lids 12 are joined to each other to reach the maximum open state (5).
[0013]
On the other hand, the second opening / closing lid 12 is rotatably supported by a support shaft 16 attached to a free play end of the stay 15. The support shaft 16 is movable in the short side direction of the second opening / closing lid 12 by a slider 17 mounted on the second opening / closing lid 12. That is, the slider 17 has a long hole 17A (see FIG. 1) extending in the short side direction of the second opening / closing lid 12, and the support shaft 16 is slidably engaged with the long hole 17A.
When the attitude of the plate surface of the second opening / closing lid 12 is substantially parallel to the direction of gravity, the support shaft 16 moves downward due to the weight of the second opening / closing lid 12, and the support shaft 16 moves in the elongated hole 17 </ b> A in the second opening / closing direction. The lid 12 moves to the end position on the free play end side. By this sliding operation, the second opening / closing lid 12 falls from the position D shown in FIG. 2 to the position E, and is stabilized at an appropriate angle as a music stand.
[0014]
A spring 18 is attached to the stay 15. The spring 18 is provided to give the stay 15 an elastic biasing force rotating in one direction.
In other words, when the first opening / closing lid 11 and the second opening / closing lid 12 are closed and in the middle of the opening state, the support shaft 16 supported by the stay 15 is rotated by the rotational bias force applied to the stay 15. 17 is maintained in one position. Therefore, while the first opening / closing lid 11 and the second opening / closing lid 12 are moved from the closed position to the open position and from the open position to the closed position by this biasing operation, the rotation axis position of the second opening / closing lid 12 is shifted to one end of the slider 17. The position of the second opening / closing cover 12 can be stably performed by maintaining the second opening / closing cover 12 at the position (hereinafter, this position is referred to as a predetermined position of the slider).
[0015]
Further, in the present invention, when the support shaft 16 moves to the end position of the second opening / closing lid 12 on the free play end side in the slider 17, the stay 15 is engaged with the second opening / closing lid 12. The first opening / closing lid 11 and the second opening / closing lid 12 are closed by the external force even when an external force in the closing direction is applied to the second opening / closing lid 12 in the open state by the engaging means. It is characterized in that it has a structure that prevents movement to the surface.
As the engaging means, in this embodiment, as shown in FIG. 1, a notch 21 formed on a metal plate constituting the stay 17 and a projection 22 formed on an edge of the stay 15 constitute an engaging means 23. Is shown. The engagement means 23 engages when the support shaft 16 moves to the free rotation end side of the second opening / closing lid 12 on the slider 17 and stabilizes to the state shown in FIG. In this state, as shown in FIG. 6, even if an external force W in the direction to close the second opening / closing lid 12 is applied to the free rotating end of the second opening / closing lid 12, the engaging means 23 is engaged, and The opening / closing lid 12 is prevented from being displaced in the closing direction, and as a result, the first opening / closing lid 11 is also prevented from being displaced in the closing direction. Therefore, it is possible to prevent an accident in which the first opening / closing lid 11 and the second opening / closing lid 12 are closed by the external force W in a state where the first opening / closing lid 11 and the second opening / closing lid 12 are open, and the player's hand is prevented. The occurrence of an accident that is pinched by the first opening / closing lid 11 can be avoided. Incidentally, reference numeral 24 shown in FIGS. 5 and 6 denotes a stopper for restricting the rotation position of the stay 15.
[0016]
When the first opening / closing lid 11 and the second opening / closing lid 12 are opened (see FIG. 4 or FIG. 5), a force is applied to the rotating free end 11A of the first opening / closing lid 11 to draw the street free end 11A forward. For (normal closing operation), a force acting upward is applied to the second opening / closing lid 12 through the hinge 13. This upward force causes the second opening / closing lid 12 to move upward, the upward movement releases the engagement means 23 from the engaged state, and the slider 17 moves the support shaft 16 relatively downward ( Slide).
By pulling the first opening / closing lid 11 further forward, the hinge 13 moves counterclockwise in this example along the arc A shown in FIG. The angle of the second opening / closing lid 12 falls toward the back side in conjunction with the movement of the first opening / closing lid 11, and approaches the vicinity of C shown in FIG. The rotation direction coincides with the rotation direction, and the stay 15 rotates according to the biasing force of the spring 18 to return the support shaft 16 to a predetermined position of the slider 17. Accordingly, since the support point of the second opening / closing lid 12 is fixed to the predetermined position of the slider 17 thereafter, the second opening / closing lid 12 can be displaced in the closing direction stably.
[0017]
Furthermore, in the present invention, when the first opening / closing lid 11 and the second opening / closing lid 12 are closed, the first opening / closing lid 11 is engaged with the buffer at a position close to the closed position, and the first opening / closing lid 11 is closed. It is characterized in that a configuration for reducing the moving speed of the second opening / closing lid 12 is added.
For this reason, in this embodiment, as shown in FIG. 1, a gear 25 that rotates integrally with the arm 14 and a rotary damper 26 that engages with the gear 25 are provided. Is shown.
[0018]
When the gear 25 engages with the rotary damper 26 in a state in which the first opening / closing lid 11 and the second opening / closing lid 12 are displaced in the closing direction, the rotary opening / closing lid 11 and the second opening / closing lid 11 are actuated by an oily damper. The movement of the lid 12 is decelerated, and the first opening / closing lid 11 and the second opening / closing lid 12 are slowly displaced in the closing direction. As a result, it is possible to prevent an accident in which a finger or the like is pinched by the first opening / closing lid 11. The rotary damper 26 has directionality, rotates without resistance when displacing the first opening / closing lid 11 and the second opening / closing lid 12 in the opening direction, and can be opened with a light force when opening the lid.
[0019]
Further, according to the present invention, when the first opening / closing lid 11 and the second opening / closing lid 12 approach the closed position, the closing generated by the gravity of the first opening / closing lid 11 and the second opening / closing lid 12 is further proposed. When the first opening / closing lid 11 and the second opening / closing lid 12 are opened using the energy when the first opening / closing lid 11 and the second opening / closing lid 12 are opened, the first opening / closing lid 11 and the second It is characterized in that an energy storage means capable of opening and closing the opening / closing lid 12 is added.
Reference numeral 28 shown in FIG. 1 indicates energy storage means. In this embodiment, as the energy storage means 28, a case is shown in which a torsion spring is mounted on the rotation support shaft of the arm 14. When the first opening / closing lid 11 and the second opening / closing lid 12 are closed, energy generated by their own weight is stored in the energy storage means 28. The energy stored in the energy storage means 28 acts as an auxiliary force in the initial state when opening the first opening / closing lid 11 and the second opening / closing lid 12, and can be opened with a light operating force.
[0020]
7 and 8 show an embodiment of the opening / closing lid proposed in claim 6 of the present invention. In this embodiment, a movable plate 30 having a width w approximately equal to that of a musical score (not shown) is provided substantially at the center of the second opening / closing lid 12. It is configured such that it can be slid upward using movement to obtain a music stand projecting further upward than the rotating free end surface 12A of the second opening / closing lid 12.
In order to allow the movable plate 30 to be movably supported by the second opening / closing lid 12, in this embodiment, a concave groove having a width w in the short side direction is formed on the front surface (the surface that becomes the front side when closed) of the second opening / closing lid 12. To form 12B. The concave groove 12B communicates with the rotating free end surface 12A of the second opening / closing lid 12, and is opened to the rotating free end surface 12A. The movable plate 30 is selected to have an area substantially equal to the area of the groove 12B, and the plain movable plate 30 is stored inside the groove 12B.
[0021]
The movable plate 30 and the support shaft 16 are connected by connecting means 40. In this embodiment, a long hole 12D communicating with the bottom surface of the concave groove 12B and the back surface 12C of the second opening / closing lid 12 is formed, and the slide plate 41 is mounted on the movable plate 30 through the long hole 12D. The long hole 12 </ b> D extends in the short side direction of the second opening / closing lid 12. This embodiment shows a case where two long holes 12D are formed. An example is shown in which the slide plate 41 is mounted on the movable plate 30 through the two long holes 12D.
On the plate surface of the slide plate 41, a cylindrical bearing 42 whose posture is aligned with the long side direction of the second opening / closing lid 12 is mounted. The support shaft 16 is penetrated through the cylindrical bearing 42 to connect the support shaft 16 and the movable plate 30. That is, in this embodiment, the support shaft 16 is inserted between the pair of stays 15 disposed on both short sides of the second opening / closing lid 12, and penetrated by the cylindrical bearing 42 at an intermediate portion between the stay 15 and the support shaft 16. The plate 30 is connected. Therefore, the connecting means 40 is constituted by the slide plate 41, the cylindrical bearing 42 and the support shaft 16.
[0022]
With this configuration, the movable plate 30 is stored in the concave groove 12 </ b> B formed in the second opening / closing lid 12 when the support shaft 16 is located at the predetermined position of the slider 17.
The first opening / closing lid 11 and the second opening / closing lid 12 approach the open position, the orientation of the plate surface of the second opening / closing lid 12 approaches a vertical position, the support shaft 16 slides with the slider 17, and the second opening / closing lid 12 is moved. When moved downward, the movable plate 30 projects from the free rotation end surface 12A of the second opening / closing lid 12 in conjunction with the sliding operation, and reaches a state shown in FIG. When the first opening / closing lid 11 and the second opening / closing lid 12 are closed, the movable plate 30 is stored in the concave groove 12B again.
[0023]
Therefore, according to the opening / closing lid proposed in claim 6 of the present invention, it is possible to obtain a music stand that is taller than the length of the second opening / closing lid 12 in the short side direction, and stably supports the tall music sheet. The benefits can be obtained.
Although the embodiment shown in FIGS. 7 and 8 has described the example in which the movable plate 30 is stored in the concave groove 12B formed on the surface of the second opening / closing lid 12, the means for storing the movable plate 30 is a concave groove. Not limited to this, for example, a plate-shaped cavity may be formed from the rotating free end surface 12B of the second opening / closing lid 12 toward the mounting position of the hinge 13, and the movable plate 30 may be movably disposed inside the cavity. However, the present invention is not limited to the groove 12B.
[0024]
【The invention's effect】
Although the above-described opening / closing lid of the present invention can be used for other than a musical instrument, the best effect is obtained particularly when applied to a keyboard musical instrument. That is, the shorter the depth dimension of the first opening / closing lid 11 is selected than the depth dimension of the second opening / closing lid 12, the longer the depth dimension of the second opening / closing lid 12 can be obtained.
Incidentally, if the depth dimension of the first opening / closing lid 11 is selected to be, for example, 1/4 of the depth dimension of the second opening / closing lid 12, as shown in FIG. 4 when the first opening / closing lid 11 and the second opening / closing lid 12 are opened. In addition, the second opening / closing lid 12 can use a length of about ／ as a music stand. In addition, since the surface of the long side 11A of the first opening / closing lid 11 can be used as a music rest, even a tall musical score can be stably supported.
[0025]
Further, since the depth dimension of the second opening / closing lid 12 can be lengthened by shortening the depth dimension of the first opening / closing lid 11, even if the depth dimension of the case 1 is shortened, the depth dimension of the second opening / closing lid 12 becomes extremely large. It won't be short. Therefore, there is an advantage that a tall music stand can be obtained even if the depth dimension of the case 1 is reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating an embodiment of the present invention.
FIG. 2 is a side view for explaining the operation of the present invention.
FIG. 3 is a side view for explaining a closed state of the opening / closing lid according to the present invention.
FIG. 4 is a side view for explaining a state in which an opening / closing lid according to the present invention is opened.
FIG. 5 is a diagram for explaining the operation of the main part of the present invention.
FIG. 6 is a view similar to FIG. 5;
FIG. 7 is a perspective view for explaining still another embodiment of the present invention.
FIG. 8 is a perspective view for explaining the operation of the embodiment shown in FIG. 7;
FIG. 9 is a side view for explaining a conventional technique.
FIG. 10 is a side view for explaining another example of the related art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case 21 Notch 1A Long side of operation side 22 Protrusion 1B Long side of back side 23 Engaging means 11 First opening / closing lid 24 Stopper 12 Second opening / closing lid 25 Gear 13 Hinge 26 Rotary damper 14 Arm 27 Buffer means 15 Stay 28 Energy Storage means 16 support shaft 30 movable plate 17 slider 40 connecting means 18 spring

Claims (6)

A. A case in which the opening surface has a substantially rectangular shape, one long side is the operation side, and the other long side is the back side,
B. A first opening / closing lid and a second opening / closing lid for opening and closing the opening surface of the case by dividing the opening surface of the case in the short side direction with the operation side being short and the rear side being long, and opening and closing the opening surface of the case;
C. A hinge for rotatably connecting the first opening / closing lid and the second opening / closing lid to each other;
D. A free end of the first opening / closing lid that extends toward the hinge in the short side direction is rotatably supported in the case, supports the first opening / closing lid, and turns the first opening / closing lid into a predetermined arc. An arm that moves along the opening and closing position and the opening position on the operation side of the case by changing the angle of the plate surface of the plate material constituting the first opening / closing lid according to each movement position;
E. FIG. A stay for moving the position of a support shaft rotatably supporting the second opening / closing lid at a predetermined position in the short side direction of the second opening / closing lid in conjunction with the arc movement of the first opening / closing lid;
F. The position of the support shaft is slid toward the free play end of the second opening / closing lid according to the weight of the second opening / closing lid in a state where the plate surface direction of the second opening / closing lid has reached a position substantially parallel to the direction of gravity. And a slider
G. FIG. A spring for applying an elastic rotational biasing force in one direction to the stay and returning the position of the support shaft to the predetermined position in a state where the sliding direction of the slider matches the rotational direction of the support shaft; ,
An opening / closing lid, comprising: 2. The opening / closing lid according to claim 1, wherein the stay and the second opening / closing lid are engaged with each other in a state where the position of the support shaft is slid toward the rotating end of the second opening / closing lid, and the second opening / closing lid is engaged with the stay. An opening / closing lid, wherein an engaging means for preventing the first opening / closing lid and the second opening / closing lid from moving in the closing direction by an external force in the closing direction is added. 3. The opening / closing lid according to claim 1, wherein the first opening / closing lid starts engaging with the arm at a position close to a closing position, and is generated by gravity applied to the first opening / closing lid and the second opening / closing lid. And a buffering means for reducing a moving speed of the first opening / closing lid and the second opening / closing lid by receiving a biasing force toward a closing position to be closed. 4. The open / close lid according to claim 1, wherein a biasing force is applied to a spring to the arm in a state where the first open / close lid moves toward the closed position, and the first open / close lid is opened by the spring. An opening / closing lid having a structure to which energy storage means for storing kinetic energy for moving in a direction is added. 5. The open / close lid according to claim 1, wherein a keyboard instrument is mounted inside the case, and the first open / close lid and the second open / close lid cover a keyboard arrangement surface of the keyboard instrument in a closed state. In the opened state, the first opening / closing lid acts as a music rest, and the second opening / closing lid acts as a music stand. 6. The opening / closing lid according to claim 5, wherein a movable plate supported on the second opening / closing lid so as to be able to freely enter and exit from a free play end surface of the second opening / closing lid, and a support shaft supported by the stay on the movable plate. An opening / closing lid, characterized in that it is provided with a connecting means for connecting.

Images