A keyboard instrument including a hammer unit which includes a plurality of hammer members each of which has an effort point provided on one end side, a load point provided on an other end side, and a fulcrum provided between the effort point and the load point, and a hammer holder which rotatably holds the plurality of hammer members, and a keyboard chassis which includes a restriction member for restricting rotations of the plurality of hammer members performed in response to key depression operations within a restriction range and in which the hammer unit is mounted, in which the hammer holder has a plurality of contact points on the effort point side which comes in contact with portions of the plurality of hammer members on the effort point side when the hammer unit is in a vertically inverted state.

A relationship of 0<.sub.1<2.sub.1 is satisfied, where .sub.1 is an angle formed between a first line which is vertical to a parallel line passing through a pivot center point and being parallel to a pivot extending direction, passes through a center point of a first portion from the center point of the first portion toward the parallel line, and a second line which is vertical, at the center point of the first portion, to a first portion extending direction, passes through the center point of the first portion toward a vertical line being vertical to the parallel line and passing through the pivot center point, and where .sub.1 is an angle formed between the first line and a third line connecting the pivot center point and the center point of the first portion from the center point of the first portion toward the pivot center point.

A relationship of 0<.sub.1<2.sub.1 is satisfied, where .sub.1 is an angle formed between a first line which is vertical to a parallel line passing through a pivot center point and being parallel to a pivot extending direction, passes through a center point of a first portion from the center point of the first portion toward the parallel line, and a second line which is vertical, at the center point of the first portion, to a first portion extending direction, passes through the center point of the first portion toward a vertical line being vertical to the parallel line and passing through the pivot center point, and where .sub.1 is an angle formed between the first line and a third line connecting the pivot center point and the center point of the first portion from the center point of the first portion toward the pivot center point.

A keyboard instrument including a hammer unit which includes a plurality of hammer members each of which has an effort point provided on one end side, a load point provided on an other end side, and a fulcrum provided between the effort point and the load point, and a hammer holder which rotatably holds the plurality of hammer members, and a keyboard chassis which includes a restriction member for restricting rotations of the plurality of hammer members performed in response to key depression operations within a restriction range and in which the hammer unit is mounted, in which the hammer holder has a plurality of contact points on the effort point side which comes in contact with portions of the plurality of hammer members on the effort point side when the hammer unit is in a vertically inverted state.

A keyboard instrument including a hammer unit which includes a plurality of hammer members each of which has an effort point provided on one end side, a load point provided on an other end side, and a fulcrum provided between the effort point and the load point, and a hammer holder which rotatably holds the plurality of hammer members, and a keyboard chassis which includes a restriction member for restricting rotations of the plurality of hammer members performed in response to key depression operations within a restriction range and in which the hammer unit is mounted, in which the hammer holder has a plurality of contact points on the effort point side which comes in contact with portions of the plurality of hammer members on the effort point side when the hammer unit is in a vertically inverted state.

A keyboard apparatus includes: a key; a hammer assembly; a first member having a step; a second member slidable relative to the first member and configured to be moved in a direction in which the second member moves over the step, when the key is pressed; and a third member configured to guide the second member such that the second member is not located at a distance greater than or equal to a predetermined distance from the first member. The third member has a shape at a region of the third member such that the third member does not contact the second member in a state in which the second member is in contact with the first member. When the second member moves over the step, the region is opposed to the second member in the direction in which the second member moves over the step.

A sensor includes: an upper electrode; a lower electrode provided facing the upper electrode; an upper electrode support portion provided in an upper portion of the upper electrode; a deforming portion provided at both ends of the upper electrode support portion and enabling a distance between the upper electrode and the lower electrode to be changed; a rotatable actuator arranged facing the upper electrode support portion; and a member arranged between the upper electrode support portion and the actuator, and capable of moving relative to at least one of the actuator and the upper electrode support portion when the actuator presses the upper electrode support portion.

A keyboard device includes: a frame; a plurality of keys including a first key and a second key, the plurality of keys rotating around the frame; and a plurality of guides for restricting an operation of each of the plurality of keys, at positions different in a vertical direction, each of the plurality of guides including a first member that is softer than the frame and the plurality of keys, and a second member that is harder than the first member, wherein each of the plurality of guides is in a first state where a corresponding one of the keys comes into contact with the first member, or in a second state where the corresponding one of the keys comes into contact with the second member.

A hammer assembly includes: a weight; and a pivot member including a first weight supporter configured to support the weight in a first direction, a second weight supporter configured to support the weight in a second direction opposite to the first direction, and a coupling portion configured to couple the first weight supporter and the second weight supporter to each other. A distance from the first weight supporter to the weight and a distance from the second weight supporter to the weight increase with decrease in distance to the coupling portion in at least a portion of a region of the weight.

A hammer assembly includes: a weight; and a pivot member including a first weight supporter configured to support the weight in a first direction, a second weight supporter configured to support the weight in a second direction opposite to the first direction, and a coupling portion configured to couple the first weight supporter and the second weight supporter to each other. A distance from the first weight supporter to the weight and a distance from the second weight supporter to the weight increase with decrease in distance to the coupling portion in at least a portion of a region of the weight.