Abstract: The present inventions provides a magnetizing apparatus 100 for magnetic particle testing of a wheel 7 that includes a hub 71, a plate 72, and a rim 73 in sequence from inward to outward in a radial direction of the wheel. The apparatus includes: a conductor 1 inserted through a bore 711 of the hub 71; and a pair of auxiliary conductors 2 connected to respective opposite end portions of the conductor 1, and so disposed as to face respective opposite side surfaces of the wheel 7, and to extend from the hub 71 to the rim 73 outwardly in a radial direction of the wheel 7, wherein the pair of auxiliary conductors 2 and the conductor 1 are energized with alternating current.

Abstract: The present inventions provides a magnetizing apparatus 100 for magnetic particle testing of a wheel 7 that includes a hub 71, a plate 72, and a rim 73 in sequence from inward to outward in a radial direction of the wheel. The apparatus includes: a conductor 1 inserted through a bore 711 of the hub 71; and a pair of auxiliary conductors 2 connected to respective opposite end portions of the conductor 1, and so disposed as to face respective opposite side surfaces of the wheel 7, and to extend from the hub 71 to the rim 73 outwardly in a radial direction of the wheel 7, wherein the pair of auxiliary conductors 2 and the conductor 1 are energized with alternating current.

Abstract: A wood member for a musical instrument, which is capable of preventing occurrence of damage, such as cracking, to thereby ensure smooth and stable operation of the musical instrument and maintain excellent appearance of the same over a long time period. The wood member has compressive internal stress remaining at least in an outer peripheral portion thereof by being subjected to heating processing, cooling processing, and moisture conditioning processing, in advance. A wood workpiece as a workpiece for the wood member is heated at a predetermined temperature, and the heated wood workpiece is cooled. The cooled wood workpiece is subjected to moisture conditioning such that compressive internal stress is generated at least in an outer peripheral portion of the wood workpiece.

Abstract: A wood member for a musical instrument, which is capable of preventing occurrence of damage, such as cracking, to thereby ensure smooth and stable operation of the musical instrument and maintain excellent appearance of the same over a long time period. The wood member has compressive internal stress remaining at least in an outer peripheral portion thereof by being subjected to heating processing, cooling processing, and moisture conditioning processing, in advance. A wood workpiece as a workpiece for the wood member is heated at a predetermined temperature, and the heated wood workpiece is cooled. The cooled wood workpiece is subjected to moisture conditioning such that compressive internal stress is generated at least in an outer peripheral portion of the wood workpiece.

Abstract: A string-striking device for a piano, where a static loading acting on a fore-end on the playing side of a key can be easily adjusted. A long weight lever (21) is provided on each key (3). The lever (21) is installed along the length direction of the key 3, on an upper part on the side opposite the playing side of the key (3). The installation is made such that one end of the lever (21) is vertically pivotably fixed to a piano body and the vertically displaceable free-end side of the lever is in contact with the upper face of the key (3) by its own weight to apply a load on the key (3). The structure above enables a static load on the key (3) to be adjusted by replacing the lever (21) without disassembling the string-striking device and removing the key (3).

Abstract: A keystroke device of a piano capable of increasing an area for the adjustment of static loads applied to the tips of keys on the playing sides, wherein a first weight lever (31) rotating according to the movement of the keys (21) is installed above the keys (21) and near an action part (25) and a second weight lever (41) rotating according to the movement of the first weight lever (31) is installed above the first weight lever. Since the second weight lever (41) can be separated from the action part (25), the degree of freedom of the shape and installation of the second weight lever (41) can be increased. Accordingly, the area for the adjustment of the static loads applied to the tips of the keys (21) on the playing sides can also be increased.

Abstract: A string-striking device for a piano, which can expand the adjustable range of the static loading applied to a fore-end on the playing side of a key. A first weight lever (31) which rotates in conformity with the motion of a key (21) is provided near an action portion (25) and above the key (21). A second weight lever (41) which rotates in conformity with the motion of the first weight lever (31) is provided above the first weight lever (31). In this manner, the second weight lever (41) can be positioned apart from the action portion (25). Thus, there is a lot of flexibility in shape and installation of the second weight lever (41). Accordingly, the adjustable range of the static loading applied to a fore-end on the playing side of the key (21) is expanded.

Abstract: A string-striking device of a piano by which static loading applied to a front end of a key on the playing side can be readily adjusted. Each key (3) is provided with a long weight lever (21) disposed along the length direction of the key 3 at an upper part of the key (3) on the side opposite of the key to the playing side. The weight lever (21) is arranged such that one end thereof is fixed to a piano body so as to allow the weight lever (21) to freely swing up and down, and the other open end, which can be vertically displaced, is brought into contact with the upper surface of the key (3) and applies its own weight on the key (3). Thus, the static loading applied to the key (3) can be adjusted by replacing the weight lever (21) without disassembling the string-striking device and removing the key (3).

Abstract: A string-striking device for a piano, where a static loading acting on a fore-end on the playing side of a key can be easily adjusted. A long weight lever (21) is provided on each key (3). The lever (21) is installed along the length direction of the key 3, on an upper part on the side opposite the playing side of the key (3). The installation is made such that one end of the lever (21) is vertically pivotably fixed to a piano body and the vertically displaceable free-end side of the lever is in contact with the upper face of the key (3) by its own weight to apply a load on the key (3). The structure above enables a static load on the key (3) to be adjusted by replacing the lever (21) without disassembling the string-striking device and removing the key (3).

Abstract: An action in an acoustic piano is provided which can reproduce the touch and feel of the key depression generated in a normal performance mode even in a silent performance mode. The acoustic piano is capable of being switched between the normal performance mode and the silent performance mode. In the silent performance mode, a rotation lever of a transmission switching mechanism disconnects the hammer operating portion from the key. A load switching mechanism is rotated to lower the tip of a weight lever to abut directly upon the upper face of the key. Then, the weight lever swings up and down corresponding to the key depression of a player, closely reproducing the touch and feel of a conventional acoustic piano.

Abstract: A string-striking device of a piano by which static loading applied to a front end of a key on the playing side can be readily adjusted. Each key (3) is provided with a long weight lever (21) disposed along the length direction of the key 3 at an upper part of the key (3) on the side opposite of the key to the playing side. The weight lever (21) is arranged such that one end thereof is fixed to a piano body so as to allow the weight lever (21) to freely swing up and down, and the other open end, which can be vertically displaced, is brought into contact with the upper surface of the key (3) and applies its own weight on the key (3). Thus, the static loading applied to the key (3) can be adjusted by replacing the weight lever (21) without disassembling the string-striking device and removing the key (3).

Abstract: An action in an acoustic piano is provided which can reproduce the touch and feel of the key depression generated in a normal performance mode even in a silent performance mode. The acoustic piano is capable of being switched between the normal performance mode and the silent performance mode. In the silent performance mode, a rotation lever of a transmission switching mechanism disconnects the hammer operating portion from the key. A load switching mechanism is rotated to lower the tip of a weight lever to abut directly upon the upper face of the key. Then, the weight lever swings up and down corresponding to the key depression of a player, closely reproducing the touch and feel of a conventional acoustic piano.

Abstract: The present invention relates to an antibacterial key for use in a keyboard of a musical instrument. The antibacterial key comprises a key stick and a key cover adhered on the upper surface of the key stick through an adhesive layer. The adhesive layer comprises an adhesive containing a volatile antibacterial agent and can readily add an antibacterial function to the key with an antibacterial effect of the antibacterial agent, which volatilizes from the adhesive layer, at a low cost irrespective of a material or a manufacturing method of the key cover.

Abstract: To provide an electronic upright piano providing a key touch of an acoustic upright piano. An action load simulation member (2) provided in the electronic upright piano is composed of a wippen (15) rotating and rising when a depressed key (11) is rotated, a jack (17) rising together with the wippen (15) until a jack tail (17a) contacts a regulating button (16), a hammer butt (18) rotatably supported by a center pin (18b) for contacting or leaving the jack (17), a hammer shank (21) connected to the hammer butt (18) and provided with a hammer (23), and a hammer stopper (32) which can contact the tip of the hammer (23). The wippen (15), the jack (17) and the hammer butt (18) are rotated about separate axes, respectively. In the electronic upright piano, the let-off timing is the same as that in an acoustic upright piano.

Abstract: To provide an electronic piano maintaining a compact appearance and providing the key touch equivalent to that of an acoustic piano. A hammer equivalent member is composed of a butt, a L-shaped member and a catcher shank. When the butt is pushed up by a jack responsive to the key depression, the hammer equivalent member starts rotating in a direction reverse to the rotary direction of a depressed key. Subsequently, after the jack leaves the butt, the hammer equivalent member continues to be rotated inertially. By contacting the projection of the L-shaped member of the hammer equivalent member, a stopper stops the inertial movement of the hammer equivalent member. The hammer equivalent member is almost equivalent to the hammer assembly of the usual acoustic piano in inertial moment and the angle formed by the center of gravity relative to a virtual perpendicular passing a center pin. Furthermore, the hammer equivalent member is shorter than the hammer assembly in appearance.

Abstract: A hammer head for a piano which is simple in structure and is capable of maintaining a humidity preventive effect for a longer time. The hammer head comprises a hammer body having a hammer felt including two flat surfaces substantially parallel to each other, and a string striking portion for striking a string, and a humidity preventive film adhered on the two flat surfaces of the hammer felt of the hammer body so as to cover the flat surfaces. A method for manufacturing such hammer heads at a low cost is also provided.

Abstract: There is provided a closing control device for a fallboard of a piano. A fallboard support is detachably mounted on a body of the piano, and the fallboard is rotatably attached to the fallboard support. A linkage has one end thereof connected to the fallboard. A slow closing device is fixed to the fallboard support, and has the other end of the linkage connected thereto, for braking the fallboard by way of the linkage when the fallboard rotates in a closing direction.

Abstract: An object is to provide an antibacterial keyboard which keeps to be clean and can be prevented from being discolored by growing or grown bacteria. Methyl methacrylate resin as acrylic resin, and a ceramic body as an antibacterial agent prepared by mixing and sintering calcium phosphate and silver metal are used: 0.5% to 2% by weight of the ceramic body prepared by mixing and sintering calcium phosphate and silver metal is blended and uniformly dispersed in the methyl methacrylate resin. The blend is injection molded, to form piano natural key coverings. The piano natural keys covered with such coverings are superior in an antibacterial, keep to be clean and can be prevented from being discolored by growing or grown bacteria.

Abstract: A bearing structure in a piano action part which can always maintain the torque of rotation of a pin shaft supporting a hammer member within a predetermined range characterized in that the bearing structure comprises a pin shaft fixed to a hammer member, a support member having through-holes through which the pin shaft passes and cloth members with which the spaces between the through-holes and the pin shaft inserted through the through-hole are packed, and that the support member is made of a cellulose derivative resin composition containing silica having a number of silanol groups of 3.0 or less per 100 square .ANG. and a BET specific surface area of 100 to 210 m.sup.2 /g, and a transmission structure in a piano characterized in that the transmission structure comprises a hammer member and the above-mentioned bearing structure.

Abstract: A black key making of a resin composition comprising a cellulose derivative resin, silicon oxide and at least 0.3 part by weight of a carbon black based on 100 parts by weight of the cellulose derivative, the carbon black having a pH of 6 and below and a BET specific surface area of 260 m.sup.2 /g and above, a keyboard comprising white keys and above-described black keys and a musical instrument having the above-described keyboard are disclosed. The black key is excellent in productivity and processability and is hygroscopic and excellent in the touch to fingers during playing. The black key is preferably made by injection molding.