Kabushiki Kaisha Kawai Gakki Seisakusho

Yutaka Tamai

Yoshiaki Shimoda

Tsutomu Yamaguchi

Kazuhiro Tsukamoto

Masanori Katsuta

Norizo Kamimura

Norizou Kamimura

A keyboard apparatus for an electronic musical instrument has a metallic keyboard chassis and a balance rail provided on the keyboard chassis. A plurality of pins are provided on the balance rail. The pins and the balance rail constitute fulcrums for swingably supporting white keys and black keys. A hammer is provided in a rear side of each of the white and the black keys so as to be swingable by swinging of each of the respective keys by a second fulcrum comprising oval cross sectional shafts extending outwardly from the side surface of one of the hammer and a bearing member, the side surface extending perpendicular to a direction of swing movement of the hammer and a pair of bearing recesses for pivotally receiving the shaft, the bearing recesses being formed in the other of the hammer and the bearing member. Each of the bearing recesses has a guide slot for guiding each of the shafts from outside into the bearing recess for assembling. A split groove is provided in the other of the hammer and the bearing member for receiving the one of the hammer and the bearing member. First abutment surfaces are provided so as to project in an axial direction of the shafts from the side surface of the one of the hammer and the bearing member around the shafts, the first abutment surfaces being in sliding contract with the slit groove. Second abutment surfaces are provided by reducing the width between the side surfaces and lateral vibration preventing surfaces are provided inside the split groove in close proximity to the second abutment surfaces.

Keyboard apparatus for electronic musical instrument

A keyboard apparatus for an electronic musical instrument has a metallic keyboard chassis and a balance rail provided on the keyboard chassis. A plurality of pins are provided on the balance rail. The pins and the balance +*rail constitute fulcrums for swingably supporting white keys and black keys. The fulcrums for the black keys are disposed on the same line with, or in front of, the fulcrums for the white keys. Hammers are provided in a rear of the keys so as to be swingable by swinging of each of the respective keys. The hammers are disposed on the same axis of rotation, and a position for the black keys to operate to swing the respective hammers is located in front of a position for the white keys to operate to swing the respective hammers such that an angle of rotation of the respective hammers becomes substantially equal to each other. A stopper member for restricting the swinging movement of the keys or the hammers are provided in a rear upper portion of the keys. The metallic key board chassis is divided into a front chassis portion and a rear chassis portion, and the two are connected by metallic reinforcing beams.

A keyboard apparatus for an electronic keyboard musical instrument comprising a wooden key which is swingably supported by a fulcrum on a metallic keyboard chassis and which is returned from its depressed position by returning means, a precisely constructed balance rail of metal or plastic is provided on the metallic keyboard chassis, and the wooden key is directly supported by the balance rail.

Keyboard apparatus for electronic keyboard musical instrument

A keyboard device has a key, a support for the key, the key being rotatably mounted on the key support, a hammer, a support for the hammer, the hammer being rotatably mounted on the hammer support, a resilient member for urging the key to swing in a direction which is the same as the direction of swinging of the key when the key is depressed and for urging the hammer to swing in a direction which is opposite to the direction of swinging of the hammer when the key is depressed. The resilient member has a first end coupled to the key and a second end coupled to the hammer.

Keyboard device for electronic musical instrument

An improved key device for an electronic keyboard musical instrument of the type having a fulcrum and a chassis each mounted on a support, and having a key pivotably mounted on the fulcrum, is further provided with a rotor rotatably coupled to the chassis. A first end of the rotor is in contact with an after-fulcrum rear end of the key. A key-returning spring is arranged to couple the rotor and the chassis. A rotation shaft member is fastened to the chassis, the rotor having a recessed portion for receiving the rotation shaft member whereby the rotor is rotatable relative to the rotation shaft member. A heavy mass portion is fastened to a second end of the rotor, the first and second ends of the rotor being on opposite sides of a rotational center of the rotation shaft member. A stopper is mounted on the chassis for suppressing vibrations of the rotor generated when the key is depressed.

Growing community of inventors

Hamamatsu, Japan

Yutaka Tamai