A rotation mechanism includes a shaft portion, a bearing portion, a protruding portion, and a stopper. The bearing portion configured to rotate with respect to a predetermined axis as a center of rotation and configured to slide relative to an outer periphery of the shaft portion. The protruding portion protrudes from the shaft portion. The stopper is integrally formed the bearing portion. The stopper faces the protruding portion. A length of the protruding portion in a direction in which the protruding portion protrudes is larger than a distance from the center of rotation to a sliding portion where the bearing portion slides relative to the outer periphery of the shaft portion.

The present disclosure relates to a piano-action. The piano-action may comprises a first moving component including a concavity structure, a second moving component including a convexity structure, wherein the convexity structure and the concavity structure are configured to match each other and capable of being clipped together, and a third moving component being thin and flexible and configured to fixedly fit between the first moving component and the second moving component when the convexity structure of the second moving component is clipped into the concavity structure of the first moving component.

The present disclosure relates to a piano-action. The piano-action may comprises a first moving component including a concavity structure, a second moving component including a convexity structure, wherein the convexity structure and the concavity structure are configured to match each other and capable of being clipped together, and a third moving component being thin and flexible and configured to fixedly fit between the first moving component and the second moving component when the convexity structure of the second moving component is clipped into the concavity structure of the first moving component.

The piano pedal depressing device helps a user to depress a piano pedal using his or her upper leg. The device can be positioned between a keyboard and a horizontal support surface upon which the piano rests. The piano pedal depressing device includes an adjustable support housing and an actuator assembly, which are operatively connected to each other.

A support device for a pivotal member of a keyboard instrument, in which opposite ends of a pivotal pin fixed to a pivotal member can be each properly positioned in the center of a pin hole, to thereby enable the pivotal member to perform efficient and stable pivotal motion. The support device that pivotally supports the pivotal member pivotally moved by key depression includes a flange body including two support walls opposed to each other with a predetermined spacing therebetween, and two pin holes which are formed in the respective support walls and in which opposite ends of the pivotal pin are inserted, respectively, and two bearings fixed in the pin holes in an inserted state and having opposite ends of the pivotal pin inserted therein, for pivotally supporting the pivotal. Each bearing is formed by a braid formed in a hollow cylindrical shape.

Piano pedal operating device for people with disabilities, which allows for said operation by pressure exerted by the back of a user, wherein said piano comprises a first, vertical axis that may move longitudinally operated by means of the right pedal; a second, transverse axis joined to the first axis; strings operated by means of keys, designed to produce sounds; and dampers operated by the second axis, designed to prolong or extinguish the sounds produced by the strings. The device comprises a magnet attached to the first axis; an electro-permanent suction cup placed above the magnet, which it attracts in order to move the dampers away from the strings; a cable that conducts an electric current to the electro-permanent suction cup, in order to annul its attraction over the magnet, and thus bring the dampers closer to the piano strings; and a switch designed to cut the current flow.

A fastening structure for fastening a to-be-fastened component to a wooden component by using a screw, wherein the wooden component is made of wood having a specific gravity of 0.08 g/cm.sup.3 to 0.85 g/cm.sup.3 inclusive, the screw has a nominal diameter of 0.8 mm to 3.5 mm inclusive, and the distance between a neutral position in a longitudinal direction of an effective screw part, which is the portion where the wooden component and a male screw part formed in a shaft part of the screw mesh together, and the surface of the wooden component that comes into contact with the to-be-fastened component is 1 mm to 15 mm inclusive.

A fastening structure for fastening a to-be-fastened component to a wooden component by using a screw, wherein the wooden component is made of wood having a specific gravity of 0.08 g/cm.sup.3 to 0.85 g/cm.sup.3 inclusive, the screw has a nominal diameter of 0.8 mm to 3.5 mm inclusive, and the distance between a neutral position in a longitudinal direction of an effective screw part, which is the portion where the wooden component and a male screw part formed in a shaft part of the screw mesh together, and the surface of the wooden component that comes into contact with the to-be-fastened component is 1 mm to 15 mm inclusive.

A fastening structure for fastening a to-be-fastened component to a wooden component by using a screw, wherein the wooden component is made of wood having a specific gravity of 0.08 g/cm.sup.3 to 0.85 g/cm.sup.3 inclusive, the screw has a nominal diameter of 0.8 mm to 3.5 mm inclusive, and the distance between a neutral position in a longitudinal direction of an effective screw part, which is the portion where the wooden component and a male screw part formed in a shaft part of the screw mesh together, and the surface of the wooden component that comes into contact with the to-be-fastened component is 1 mm to 15 mm inclusive.

A fastening structure for fastening a to-be-fastened component to a wooden component by using a screw, wherein the wooden component is made of wood having a specific gravity of 0.08 g/cm.sup.3 to 0.85 g/cm.sup.3 inclusive, the screw has a nominal diameter of 0.8 mm to 3.5 mm inclusive, and the distance between a neutral position in a longitudinal direction of an effective screw part, which is the portion where the wooden component and a male screw part formed in a shaft part of the screw mesh together, and the surface of the wooden component that comes into contact with the to-be-fastened component is 1 mm to 15 mm inclusive.