| 摘要 |
<p>PURPOSE: To provide a frame which may be provided with a function as structural materials, such as backposts, by subjecting the frame to a treatment to enhance the dimensional accuracy of the frame without requiring special equipment even if the frame of the state produced by casting, etc., is low. CONSTITUTION: A wooden plate material 5 as a buffer material 4b is fixed by means of screws 4f to the flank 4c of a casting body 4a of the frame 4. This fixing is executed with the peripheral edges on the four sides of the casting body 4a. Next, the wooden plate materials 5 mounted to the peripheral edges on the four sides of the casting body 4a are cut by the same device as the four-way cutting device used heretofore to obtain the dimensional accuracy by cutting the four sides of the combined backposts, by which the surfaces 4d for arranging treble and bass end panels, roof rear and bottom plate in correct positions are completed. Then, the subsequent assembly of the piano may be executed by using the surfaces 4d on the circumference of the frame 4 as reference, by which the assembly of the treble and bass end panels, roof rear, bottom plate, etc., is executed with the same high accuracy as in the case of the assembly executed heretofore by using the faces on the circumference of the sound ribs as reference.</p> |
