Abstract:
A fallboard arrangement for a keyboard instrument, including a slide-type fallboard and enabling enhancing the degree of freedom of design while ensuring good appearance and smooth opening and closing operation of the fallboard, to improve marketability. A fallboard opens and closes a performance section. Arms have respective guide grooves for guiding sliding of the fallboard in a front-rear direction. Left and right side plates are provided for left and right ends of a front portion of the fallboard, and have shield walls for shielding areas around left and right end faces of the fallboard, respectively. Left and right guide bushes protrude outward from the side plates, for engagement with the guide grooves of the respective arms. The guide bushes are guided by the guide grooves of the respective arms during sliding of the fallboard in the front-rear direction.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Japanese Patent Application Number 100268/2012, filed on Apr. 25, 2012, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a fallboard arrangement for a keyboard instrument, which is capable of opening and closing a performance section of the keyboard instrument by sliding a fallboard of the keyboard instrument. 
     2. Description of the Related Art 
     Conventionally, as a fallboard arrangement for a keyboard instrument, there has been known one disclosed e.g. in Japanese Laid-Open Patent Publication (Kokai) No. 2000-305556. The fallboard arrangement is applied to an electronic piano, and includes a fallboard. The fallboard is mounted on the piano body of the electronic piano such that it can slide in a front-rear direction between a closed position for closing a performance section of the electronic piano and an open position for opening the same. The fallboard has a laterally elongated fallboard front section secured to the front end thereof with screws, and left and right front guide protrusions protruding from the lower end of the fallboard front section. The front guide protrusions protrude outward from the respective left and right ends of the fallboard front section, and are engaged with front guide grooves of respective left and right arms of the piano body. 
     Further, the fallboard has a laterally elongated fallboard rear section secured to the rear end thereof with screws, and left and right rear guide protrusions and left and right pinions protruding from the fallboard rear section. The left and right pinions protrude outward from the respective left and right ends of the fallboard rear section, and are in mesh with racks of the respective left and right arms of the piano body. The left and right rear guide protrusions protrude further outward than the left and right pinions, and are engaged with rear guide grooves of the respective left and right arms of the piano body. 
     With the above-described arrangement, in the fallboard arrangement, when the fallboard is manually drawn forward or pushed rearward, the front guide protrusions are guided by the respective front guide grooves, and the rear guide protrusions are guided by the respective rear guide grooves, while the pinions rotate in mesh with the respective racks. Thus, the fallboard slides in the front-rear direction while preventing large gaps from being formed between the upper edges of the respective arms and the associated lower edges of the fallboard during sliding of the fallboard. This is because if such gaps are formed, the appearance of the electronic piano is degraded, and there is a fear that smooth sliding of the fallboard can be hindered due to entrance of foreign matter into the gaps. 
     As described above, according to the fallboard arrangement disclosed in Japanese Laid-Open Patent Publication (Kokai) No. 2000-305556, with a view to ensuring good appearance and smooth opening and closing operation, it is required to prevent large gaps from being formed between the upper edges of the respective arms and the lower edge of the fallboard during sliding of the fallboard in the front-rear direction. For this reason, the upper edges of the arms and the front guide grooves are limited in positional relationship therebetween and shape, which results in a low degree of freedom of design. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a fallboard arrangement for a keyboard instrument, which includes a slide-type fallboard and makes it possible to enhance the degree of freedom of design while ensuring good appearance and smooth opening and closing operation of the fallboard, to thereby improve the marketability of the keyboard instrument. 
     To attain the above object, the present invention provides a fallboard arrangement for a keyboard instrument, for opening and closing a performance section including a keyboard disposed within an instrument body, by being slid in a front-rear direction, comprising a fallboard mounted to the instrument body, for opening and closing the performance section, a pair of left and right arms provided in the instrument body such that the pair of left and right arms extend in the front-rear direction at locations outward of respective left and right ends of the fallboard, the pair of left and right arms having respective guide grooves for guiding sliding of the fallboard in a front-rear direction, a pair of left and right shield members provided for the respective left and right ends of the fallboard such that the pair of left and right shield members extend downward from the fallboard, the pair of left and right shield members having respective shield walls for shielding areas around respective left and right end faces of the fallboard, respectively, and a pair of left and right protruding members protruding outward from the shield walls of the pair of left and right shield members, respectively, for engagement with the guide grooves of the pair of left and right arms, the protruding members being guided by the guide grooves of the pair of left and right arms during sliding of the fallboard in the front-rear direction. 
     According to this fallboard arrangement for a keyboard instrument, the pair of left and right protruding members are guided by the guide grooves of the pair of left and right arms, respectively, whereby the fallboard slides in the front-rear direction. During the above-described opening and closing operation of the fallboard, even if gaps may be formed between the lower edges of the fallboard and the upper edges of the respective arms due to the positional relationship between the arms and the respective associated guide grooves and the shapes of the arms and the guide grooves, the gaps can be shielded by the respective shield walls since each of the left and right shield members fixed to the respective left and right ends of the front portion of the fallboard has the shield wall extending downward from the fallboard in a manner shielding an area around an associated one of the left and right end faces of the fallboard. This makes it possible to enhance the degree of freedom of design while maintaining excellence in the appearance of the fallboard and smooth opening and closing operation of the same, to thereby improve the marketability of the product. 
     Preferably, each of the pair of left and right protruding members is fixed to the fallboard via a fixing piece integrally with an associated one of the pair of left and right shield members. 
     With the arrangement of this preferred embodiment, it is possible to integrally fix each of the protruding members and an associated one of the shield members to the fallboard by using a single fixing piece. This makes it possible to reduce the number of assembly steps and the number of components in comparison with a case where each protruding member and an associated shield member are separately fixed to a fallboard via respective different fixing pieces, which contributes to reduction of manufacturing costs. 
     Preferably, each of the pair of left and right protruding members and an associated one of the pair of left and right shield members are integrally formed with each other. 
     With the arrangement of this preferred embodiment, each of the protruding members and an associated one of the shield members are integrally formed therewith, so that it is possible to reduce the number of components in comparison with a case where each protruding member and an associated shield member are separately formed, which contributes to reduction of manufacturing costs. 
     Preferably, the fallboard further comprises a fallboard front section provided at a front end of the fallboard such that the fallboard front section extends in a left-right direction, and the pair of left and right shield members are fixed to the fallboard in a manner shielding left and right sides of the fallboard front section, respectively. 
     With the arrangement of this preferred embodiment, the shield members are fixed to the fallboard in a manner shielding the respective left and right sides of the fallboard front section, so that even when the left and right sides of the fallboard front section reach locations above the upper edges of the respective left and right arms during sliding of the fallboard in the front-rear direction, it is possible to shield the left and right sides of the fallboard front section by the respective shield walls. Thus, even when the fallboard is provided with the fallboard front section, it is possible to enhance the degree of freedom of design while maintaining excellence in the appearance of the fallboard and smooth opening and closing operation of the same, to thereby improve marketability of the product. 
     Preferably, the shield members are made of a synthetic resin material. 
     In a case where a pair of shield members are provided for respective left and right ends of the front portion of the fallboard, if the shield members are made of a hard material, such as a metal, there is a fear that the surfaces of the respective arms can be scratched due to contact between the shield members and the arms during sliding of the fallboard. With the arrangement of this preferred embodiment, since the shield members are made of a synthetic resin, it is possible to suppress scratches from being made on the surfaces of the respective arms in comparison with the case where the shield members are made of a hard material, such as a metal, and therefore the marketability of the product can be further improved. In the case of the fallboard arrangement as recited in appended claim  4 , since the pair of shield members are fixed to the fallboard in a manner shielding the respective left and right sides of the fallboard front section, even if the fallboard front section is made of a hard material, such as a metal, it is possible to prevent the surfaces of the respective arms from being scratched, and therefore the degree of freedom of design and the marketability of the product can be further improved. 
     The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side transparent view of an electronic piano including a fallboard arrangement according to an embodiment of the present invention with a fallboard in a closed position; 
         FIG. 2  is a side transparent view of the electronic piano with the fallboard in an open position; 
         FIG. 3  is an exploded perspective view of a side plate and component parts associated therewith; 
         FIG. 4  is a side view of the side plate and component parts associated therewith; 
         FIG. 5  is a side transparent view of the fallboard in a position between the closed position and the open position; and 
         FIG. 6  is an enlarged view of the side plate and component parts associated therewith appearing in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention will now be described in detail with reference to the drawings showing a preferred embodiment thereof.  FIG. 1  shows a fallboard arrangement  1  for a keyboard instrument, according to the embodiment of the present invention. As shown in  FIG. 1 , the fallboard arrangement  1  of the present embodiment is applied to an electronic piano  2  as the keyboard instrument. The electronic piano  2  includes a piano body  3  (instrument body) and the fallboard arrangement  1  having a fallboard  10  for opening and closing a performance section  4  of the piano body  3 . The piano body  3  is an assembly of plywood members, steel members, and so forth, and includes left and right arms  6  and  6  (only one of which is shown in  FIG. 1 ) each extending in the front-rear direction. The arms  6  and  6  are formed by laminating a vinyl chloride sheet (or an olefin-based resin sheet) to the surface of a wood material, such as MDF material, and a keyboard  5  and an operation panel (not shown) are arranged in the performance section  4  between the arms  6  and  6 . 
     Each of the left and right arms  6  and  6  has an inner surface thereof formed with front and rear grooves each extending in the front-rear direction, and a front guide rail  7  and a rear guide rail  8  are fitted in the front and rear grooves, respectively. The left and right front guide rails  7  and  7  (only one of which is shown) and the left and right rear guide rails  8  and  8  (only one of which is shown) are bilaterally symmetrically arranged. 
     Each of the front guide rails  7  extends vertically upward from the front end of the piano body  3  along the inner surface of the arm  6 , then from the uppermost portion, extends obliquely upward and rearward toward the front end of the rear guide rail  8 , and a rear end thereof extends slightly obliquely downward and rearward. Each of the front guide rails  7  is formed by a resin molded article having an inwardly open U-shape (not shown) in cross section. The open portion of each front guide rail  7  serves as a front guide groove  7   a  (guide groove). The front guide groove  7   a  extends over the whole length of the front guide rail  7  and has an open rear end. The front guide rail  7  is secured to the arm  6  with screws such that the inner end thereof is flush with the inner surface of the arm  6 . 
     Each of the rear guide rails  8  is secured to the arm  6  with screws in a manner extending over a long distance in the front-rear direction, and is formed with a rear guide groove  8   a  and a rack  8   b . The rear guide groove  8   a  and the rack  8   b  are arranged parallel to each other in the mentioned order from the outside and are integrally formed with each other. Further, the rear guide groove  8   a  and the rack  8   b  each extend over the whole length of the rear guide rail  8  in the front-rear direction. The rear guide groove  8   a  is rectangular in cross section (not shown) and open inwardly. The rack  8   b  is disposed at a location slightly downward of the bottom surface of the rear guide groove  8   a.    
     The fallboard  10  is mounted on the piano body  3  such that it can slide in a front-rear direction between a closed position for closing the performance section  4  as illustrated in  FIG. 1  and an open position for opening the same as illustrated in  FIG. 2 . As shown in  FIGS. 3 and 4 , the fallboard  10  includes a fallboard main section  11 , a fallboard front section  12 , left and right side plates  13  and  13  (only one of which is shown), left and right guide bushes  14  and  14  (only one of which is shown), and left and right fixing pins  15  and  15  (only one of which is shown). The fallboard main section  11  is formed by a laterally elongated rectangular plate (e.g. an MDF material having a vinyl chloride sheet or an olefin-based resin sheet laminated to a surface thereof). The fallboard main section  11  has a width slightly smaller than a distance between the inner surfaces of the respective left and right arms  6  and  6 , and a depth which is large enough to cover the performance section  4  together with the fallboard front section  12 . 
     The fallboard front section  12  is formed by an extrusion molded article of a light alloy (e.g. an aluminum alloy) and is mounted to the front end of the fallboard main section  11 . The fallboard front section  12  comprises a flat base plate portion  12   a  and a mounting portion  12   c  extending obliquely downward from the base plate portion  12   a . The base plate portion  12   a  is formed with a plurality of round holes  12   b  (only two of which are shown). The base plate portion  12   a  is rigidly secured to the fallboard main section  11  in a state in contact with the lower surface thereof by inserting screws (not shown) through the respective round holes  12   b  and screwing the screws into the fallboard main section  11 . The base plate portion  12   a  has a front end protruding obliquely forward and downward from the front end of the fallboard main section  11 . The mounting portion  12   c  has a front end thereof formed with a fixing hole  12   d  having a C shape in cross section and extending over the whole length of the mounting portion  12   c  in the left-right direction. 
     Each of the left and right side plates  13  (shield members) is made of an ABS resin and has a flat side wall portion  13   a  and a flat upper wall portion  13   c . The side wall portion  13   a  (shield wall) extends in the front-rear direction, and has a downward protrusion height that is largest in the front portion of the side wall portion  13   a  and is progressively reduced rearward. The side wall portion  13   a  has a lower end thereof formed with a round hole  13   b . The upper wall portion  13   c  extends inward from a portion of the side wall portion  13   a  extending from a central portion thereof to the rear end thereof, and is formed with two laterally elongated cutout holes  13   d  and  13   d . The upper wall portion  13   c  is rigidly secured to the fallboard main section  11  in a state in contact with the lower surface thereof by inserting screws  16  through the respective cutout holes  13   d  and screwing the screws into the fallboard main section  11 . In this state, the side wall portions  13   a  of the respective side plates  13  shield the left and right opposite sides of the fallboard front section  12 , respectively. 
     Each of the left and right guide bushes  14  (protruding members) is made of a synthetic resin and has a hollow cylindrical shape. The guide bushes  14  are fixed to the fallboard front section  12  by the respective left and right fixing pins  15  (fixing pieces). The guide bushes  14  protrude outward from the side wall portions  13   a  of the respective side plates  13  for engagement with the front guide grooves  7   a  of the respective front guide rails  7 . Each of the fixing pins  15  has a tapping screw-type screw portion  15   a  extending from a central portion thereof to a tip end thereof. The screw portion  15   a  is screwed into the fixing hole  12   d  of the fallboard front section  12  through an inner hole  14   a  of the associated guide bush  14  and the round hole  13   b  of the associated side plate  13 , whereby the guide bush  14  is fixed to the fallboard front section  12  integrally with the side plate  13 . 
     As shown in  FIGS. 1 and 2 , a fallboard rear section  17  is mounted to the rear end of the fallboard main section  11 . The fallboard rear section  17  is formed by bending a metal plate (e.g. a steel plate), and is secured to the fallboard main section  11  in a state in contact with the lower surface of the same with screws. The fallboard rear section  17  has a rotary shaft  17   a  rotatably mounted thereto. The rotary shaft  17   a  extends in the left-right direction, and opposite ends thereof function as engaging portions for engagement with the rear guide grooves  8   a  and  8   a  of the respective rear guide rails. Further, a portion of the rotary shaft  17   a  inward of the left and right engaging portions has left and right pinions  17   b  and  17   b  (only one of which is shown) integrally formed therewith. The pinions  17   b  and  17   b  are in mesh with the racks  8   b  and  8   b  of the respective left and right rear guide rails. 
     In the fallboard arrangement  1  constructed as above, when the fallboard  10  is to be opened, the fallboard  10  in the closed position is pushed rearward while being lifted upward. In accordance with this operation, the engaging portions of the respective guide bushes  14  and those of the rotary shaft  17   a  are guided by the respective front and rear guide grooves  7   a  and  8   a , and the pinions  17   b  are rotated in mesh with the respective racks  8   b , whereby the fallboard  10  is slid rearward and opened. On the other hand, when the fallboard  10  is to be closed, the fallboard  10  in the open position is drawn forward. In accordance with this operation, the engaging portions of the respective guide bushes  14  and those of the rotary shaft  17   a  are guided by the respective front and rear guide grooves  7   a  and  8   a , and the pinions  17   b  are rotated in mesh with the respective racks  8   b , whereby the fallboard  10  is slid forward and closed. 
     In the fallboard arrangement  1  of the present embodiment, during the above-described opening and closing operation of the fallboard  10 , gaps are formed between the lower edges of the fallboard main section  11  and the upper edges of the arms  6  on the respective opposite left and right sides of the fallboard  10  as shown in  FIGS. 5 and 6 , but it is possible to shield the gaps by the respective side plates  13 . In addition to this, the left and right side plates  13  and  13  are fixed to the fallboard main section  11  in a manner shielding the opposite left and right sides of the fallboard front section  12 , so that even when each of the opposite left and right sides of the fallboard front section  12  reaches a position above the upper edge of the associated arm  6  during sliding of the fallboard  10  in the front-rear direction, the opposite left and right sides of the fallboard front section  12  can be shielded by the respective two side plates  13  and  13 . This makes it possible to enhance the degree of freedom of design while maintaining excellence in the appearance of the fallboard and smoothness in the opening/closing operation of the same, to thereby improve the marketability of the product. 
     Further, it is possible to integrally fix each of the side plates  13  and an associated one of the guide bushes  14  to the fallboard main section  11  simply by using a single fixing pin  15 . This makes it possible to reduce the number of assembly steps and the number of components in comparison with a case where the side plate  13  and the guide bush  14  are separately fixed to the fallboard main section  11  via respective different fixing pieces, which contributes to reduction of manufacturing costs. 
     Further, since the side plate  13  is made of the ABS resin, it is possible to suppress the surface (inner surface) of the arm  6  from being scratched in comparison with a case where the side plate  13  is made of a hard material, such as a metal. In addition, the side plates  13  are fixed to the fallboard main section  11  in a manner shielding the left and right opposite sides of the fallboard front section  12 , so that even though a metal fallboard front section  12  is used, it is possible to prevent the surface of the arm  6  from being scratched, thereby further improving the degree of freedom of design and the marketability of the product. 
     Although in the present embodiment, the fallboard arrangement of the present invention is applied to the electronic piano  2  as a keyboard instrument, this is not limitative, but the present invention is applicable to various kinds of keyboard instruments. For example, the fallboard arrangement of the present invention may be applied to an electronic organ, a synthesizer, and the like. 
     Further, although in the present embodiment, the side plates  13  are used as the shield members, this is not limitative, but any other shield member may be used insofar as the member has a shield wall for shielding an area around each of the left and right end faces of the fallboard. 
     Although in the present embodiment, the shield members made of the ABS resin as the shield members, the material of each shield member is not limited to the ABS resin, but any other synthetic resin may be used. For example, it is possible to use an ASA resin, an ACS resin, or an AES resin to form the shield member. 
     Although in the present embodiment, the guide bush  14  is used as a protruding member, this is not limitative, but any suitable protruding member may be used insofar as it is configured to protrude outward from the shield wall of the shield member to be engaged with the guide groove of the arm such that the member can be guided by the guide groove of the arm when the fallboard slides in the front-rear direction. 
     Although in the present embodiment, the fixing pin  15  is used as a fixing piece, this is not limitative, but any suitable fixing piece may be used insofar as it is capable of integrally fixing the protruding member and the shield member to the fallboard. 
     Although in the present embodiment, the side plate  13  and the guide bush  14  are configured to be separate components, this is not limitative, but the side plate  13  and the guide bush  14  may be integrally molded into a one-piece product. 
     It is further understood by those skilled in the art that the foregoing is a preferred embodiment of the invention, and that various changes and modifications may be made without departing from the spirit and scope thereof.