| 摘要 |
<p>An adjustable pitch drum consists of a drum shell having an open end, a drum head pitch changing mechanism, and a supporting structure mounting the pitch changing mechanism to the drum shell. The pitch changing mechanism consists of a threaded rod adjustably threaded to the supporting structure, a drum head clamping hoop mounted coaxially on the rod for rotation thereabout, and a drum head tensioning hoop nonrotatably mounted on the other end of the rod. Rotation of the drum head and its clamping hoop about the rod varies the tension of the drum head on the tensioning hoop, thereby changing the pitch of the drum. Movement of the threaded rod in the supporting structure changes the spacing of the drum head from the drum shell open end, thereby changing the resonance characteristics of the drum assembly. The supporting structure comprises a rigid multi-legged spider, preferably having legs of adjustable length, which supports said rod and has said legs shaped to fit over the peripheral edge of a drum shell and be held in place by a drum hoop.</p> |
