Spensley Horn Jubas & Lubitz
Upright piano equipped with coupling units for horizontally supporting key bed
 It is important for an upright piano to keep a keyboard on a key bed horizontal, and the key bed is supported by a frame through coupling units, wherein each of the coupling units has a wedged member interposed between a projection of the frame and a bracket of the coupling unit or between the bracket and the key bed for regulating the horizontality of the keyboard. 
Yamaha Corporation
G
G10C
inventional
Hideo Hisao Takane
Yamashita Mori Sato