| 摘要 |
A shutter holder has a frame-like base portion and a tie plate inwardly projecting from a side portion of the base portion in a cantilever fashion, and the tie plate has a rectangular cross section smaller in thickness and/or width, i.e., second moment of inertia than the cross section of the base plate at the boundary; even if a staple is deeply driven into a moving object such as a wooden key, the tie plate is widely deflected so as to absorb the deformation of the wooden key, and permits a shutter plate to keep itself perpendicular to the lower surface of the wooden key.
|
