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 keyboard apparatus includes a plurality of keys each rotatable with a predetermined stroke, a support assembly which includes a support with one side rotatably arranged with a support rail and a jack with the one side rotatably supported by the support, and rotates with depression of any of the plurality of keys, a hammer unit which is operated by receiving an action of the jack, a shank rail which rotatably supports the hammer unit, and a jack stopper which makes contact with the jack which rotates with the depression of any of the plurality of keys, the jack stopper being placed on a rotation path of the jack and provided to a fixing portion which does not rotate with the depression any of the plurality of keys.

A keyboard apparatus includes a plurality of keys each rotatable with a predetermined stroke, a support assembly which includes a support with one side rotatably arranged with a support rail and a jack with the one side rotatably supported by the support, and rotates with depression of any of the plurality of keys, a hammer unit which is operated by receiving an action of the jack, a shank rail which rotatably supports the hammer unit, and a jack stopper which makes contact with the jack which rotates with the depression of any of the plurality of keys, the jack stopper being placed on a rotation path of the jack and provided to a fixing portion which does not rotate with the depression any of the plurality of keys.

A keyboard apparatus includes: a key disposed so as to be pivotable with respect to a frame; a first member, an elastic member being disposed on at least a portion of a surface of the first member; a second member configured to be moved on the elastic member while elastically deforming the elastic member in response to pivotal movement of the key; and a hammer assembly connected to the key via the first member and the second member so as to pivot in response to pivotal movement of the key.

A pressing surface of a hammer and a to-be-pressed surface of a key switch have relatively-concaved shapes in a longitudinal direction of the hammer. When a switch body is pressed by the hammer, an inclination caused by an overall curvature of the switch body that results from the fact that the switch body is pressed by the hammer from an oblique direction is canceled by an inclination of the switch body caused by partial compression and deformation that results from the relatively-concaved shapes, so that movable contacts in the switch body frontally face stationary contacts and come into contact with the stationary contacts, respectively.

A pressing surface of a hammer and a to-be-pressed surface of a key switch have relatively-concaved shapes in a longitudinal direction of the hammer. When a switch body is pressed by the hammer, an inclination caused by an overall curvature of the switch body that results from the fact that the switch body is pressed by the hammer from an oblique direction is canceled by an inclination of the switch body caused by partial compression and deformation that results from the relatively-concaved shapes, so that movable contacts in the switch body frontally face stationary contacts and come into contact with the stationary contacts, respectively.

A hammer assembly includes: a pivot member that pivots about a pivot axis; and a weight supported by the pivot member and including a plate portion. The plate portion has a first surface and a second surface opposite to the first surface. The plate portion has: a first region with a thickness defined by a length between the first surface and the second surface in a pivot-axis direction at a portion farthest from the pivot axis; and a second region with a thickness greater than that in the first region. In a case where the areas of the first region and the second region on a projected plane when the first region and the second region are viewed in the pivot-axis direction are compared with each other, the area of the first region is less than the area of the second region.

A hammer assembly includes: a pivot member that pivots about a pivot axis; and a weight supported by the pivot member and including a plate portion. The plate portion has a first surface and a second surface opposite to the first surface. The plate portion has: a first region with a thickness defined by a length between the first surface and the second surface in a pivot-axis direction at a portion farthest from the pivot axis; and a second region with a thickness greater than that in the first region. In a case where the areas of the first region and the second region on a projected plane when the first region and the second region are viewed in the pivot-axis direction are compared with each other, the area of the first region is less than the area of the second region.

A support assembly according to one embodiment of the present invention is provided, the support assembly including a jack rotatably supported by a support; a repetition lever rotatably supported with respect to the support; a protrusion disposed at an intersecting portion of the jack and the repetition lever; and a protrusion receiving portion for receiving the protrusion; wherein the protrusion receiving portion defines a movable range of the protrusion and limits a rotation range of the jack.

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.