Keyboard assembly and method of manufacturing it

A manufacturing method for a keyboard assembly which is constructed by a key being supported by a support member to have a capability of free reciprocating motion, a mechanical magnification system of an operation speed being interlocked with the key at a key-depression mode, a mass body being interlocked with an output of the mechanical magnification system to perform a reciprocating motion, and tone-generation control means for controlling tone generation by key depression of the key,

• said manufacturing method comprising the steps of:
• setting prescribed values to key-depression force F, a maximal moving distance D at a key-depression position of the key and a time T required to achieve a key-depression operation corresponding to the maximal moving distance D;
• and
• determining a mass m of the mass body and a magnification ratio k of the operation speed of the mechanical magnification system in accordance with a relational expression of
• k.sup.2 m.apprxeq.(FT.sup.2)/(2D).

A keyboard assembly for a keyboard instrument, comprising:

• a key which is supported by a support member to have a capability of free reciprocating motion;
• an intermediate moving member which is interlocked with the key at a key-depression mode to perform a reciprocating motion within a prescribed range of distance;
• a large-mass moving member which is interlocked with the intermediate moving member to perform a reciprocating motion within a prescribed range of distance;
• and
• tone-generation control means for controlling tone generation by key depression of the key,
• wherein at the key-depression mode, a center of mass of the large-mass moving member rotates upwardly about a rotation center thereof from a rest position which corresponds to an approximately horizontal place to a rotation position which corresponds to an approximately vertical place, so that at the rotation position, the center of mass of the large-mass moving member is located closer to the rest position rather than a vertical line passing through the rotation center of the large-mass moving member.

A keyboard assembly for a keyboard instrument, comprising:

• a key which is supported by a keyboard frame to have a capability of rotating up and down about a rotation center;
• a first moving member which is arranged beneath the key and which is subjected to rotary motion about a first rotation center while being interlocked with depression of the key, so that a back portion of the first moving member rotates up;
• a second moving member which is greater in mass and has a longer moving distance as compared with those of the key and those of the first moving member, wherein the second moving member being normally located at a rest position is subjected to rotary motion about a second rotation center in response to a press-up motion of the back portion of the first moving member, so that the second moving member rotates backwardly and is stopped at a contact member, then, the second moving member is subjected to back checking by which the second moving member is slightly moved forward and is temporarily fixed in position as long as the depression of the key is maintained;
• and
• a tone-generating element for producing a musical tone in response to the depression of the key,
• wherein a center of mass of the key is located forwardly from the rotation center thereof, a center of mass of the first moving member is located backwardly form the first rotation center thereof, and a center of mass of the second moving member is normally located forwardly from the second rotation center thereof, while the center of mass of the second moving member at the contact position is located slightly forward for the second rotation center thereof.

A keyboard assembly comprising:

• a support member;
• a first rotation member which is fixed to the support member to have a capability of free rotation and which is swung by a driven portion thereof being driven;
• and
• a second rotation member which is fixed to the support member to have a capability of free rotation and which is swung in response to force that a driving portion of the first rotation member transmits to a driven portion thereof,
• wherein at a non-rotation mode, the driving portion of the first rotation member is placed in contact with the driven portion of the second rotation member with rigidity, while as rotations of the first rotation member and the second rotation member progress, the driving portion of the first rotation member and the driven portion of the second rotation member contact with each other in an elastic manner.

A keyboard assembly comprising:

• a support member;
• a key which is fixed to the support member to have a capability of free swing;
• a first rotation member which is fixed to the support member to have a capability of free rotation and which is swung by a driving portion of the key which is depressed down;
• and
• a second rotation member which is fixed to the support member to have a capability of free rotation and which is swung by force that a driving portion of the first rotation member transmits to a driven portion thereof when the key is depressed down,
• wherein at a non-rotation mode, the driving portion of the first rotation member is placed in contact with the driven portion of the second rotation member with rigidity, while as rotations of the first rotation member and the second rotation member progress, the driving portion of the first rotation member contacts with the driven portion of the second rotation member in an elastic manner.

A keyboard assembly for a keyboard instrument, comprising:

• a key which is supported by a support member to have a capability of free reciprocating motion;
• an intermediate moving member which is interlocked with the key at a key-depression mode to perform a reciprocating motion within a prescribed range of distance;
• a large-mass moving member which is interlocked with the intermediate moving member to perform a reciprocating motion within a prescribed range of distance;
• and
• a tone-generation control whose tone generation is controlled by the key which is depressed,
• wherein the large-mass moving member has a greater weight and a longer moving distance as compared with those of the key and those of the intermediate moving member, the large-mass moving member being subjected to rectilinear motion guided by a guide portion, and wherein the large-mass moving member has a longer moving distance from a center of mass thereof as compared with the key and the intermediate moving member.

A keyboard assembly comprising:

• a support member;
• a first rotation member which is fixed to the support member to have a capability of free rotation and which is swung by a driven portion thereof being driven;
• a second rotation member which is fixed to the support member to have a capability of free rotation and which is swung in response to force that a driving portion of the first rotation member transmits to a driven portion thereof, wherein at a non-rotation mode, the driving portion of the first rotation member is placed in contact with the driven portion of the second rotation member with rigidity;
• a positional regulating means that is located in proximity to the driving portion of the first rotation member and the driven portion of the second rotation member for stopping the rotation of the second rotation member at its rotation end position wherein the rotation of the second rotation member is made such that the driving portion of the first moving member drives the driven portion of the second rotation member;
• and
• a back-check member which stops a return motion of the second rotation member at a relatively proximal position of the first rotation member and the second rotation member, rotations of which are stopped by the positional regulating means.

A keyboard assembly comprising:

• a support member;
• a key which is fixed to the support member to have a capability of free swing;
• a first rotation member which is fixed to the support member to have a capability of free rotation and which is swung by a driven portion of the key which is depressed down;
• a second rotation member which is fixed to the support member to have a capability of free rotation and which is swung by force that a driving portion of the first rotation member transmits to a driven portion thereof when the key is depressed down, wherein at a non-rotation mode, the driving portion of the first rotation member is placed in contact with the driven portion of the second rotation member with rigidity;
• a positional regulating means that is located in proximity to the driving portion of the first rotation member and the driven portion of the second rotation member for stopping the rotation of the second rotation member at its rotation end position wherein the rotation of the second rotation member is made such that the driving portion of the first moving member drives the driven portion of the second rotation member;
• and
• a back-check member which stops a return motion of the second rotation member at a relatively proximal position of the first rotation member and the second rotation member, rotations of which are stopped by the positional regulating means.