| 摘要 |
A kettledrum or the like incorporating a tuning mechanism whereby the timpanist may change the pitch of the drumhead over a range of at least a full octave by merely moving a foot pedal and without making any other adjustments. A linkage and counter-balancing spring means are so related to each other that the torques in opposite directions about a pivot point remain generally balanced throughout the full octave range, in order that the timpanist may achieve any desired pitch in a simple and accurate manner and without the necessity for excessive foot pressure. Friction brake means are employed to insure that the pedal will remain in any position to which it is adjusted by the timpanist, but the indicated torques are such that the amount of drag required from the friction brake is not great. Two interconnected four-bar linkages connect the foot pedal with the drumhead. One of such linkages is associated with a fine-tuning means which is readily adjustable by the timpanist without leaning over the drumhead. Such fine-tuning means complements a quick-acting master-tuning element. The linkages and associated elements are such that there is no "hair trigger" action at any portion of the scale. Instead, a reasonable degree of foot pedal pivot is required to change from any desired pitch to the pitch next higher or next lower. Means are provided to lock the foot pedal, when the instrument is not in use, in order to achieve various benefits including ease of drumhead changing.
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