Abstract: Percussion instrument including a tensioning mechanism for the head, comprising a number of threaded bushings mounted about the periphery of the instrument wall, each with a screw adjustable therein acting on a hoop holding the skins; each bushing has on its circumference a tangential slot which a peripheral section of a spring ring engages under tension; each screw has on its shank a peripheral catch surface for that peripheral section of the spring ring which lies in the slot of the bushing.

Abstract: A lug assembly for stretching drum heads by using lug bolts, including a bushing adapted for screw engagement with the lug bolt, a seat and an elastic insert which are received in corresponding grooves formed in an extension member. The extension member is formed on an inner wall of the casing, and the elements are resiliently wedged against movement as a result of the biasing force of the elastic insert and as a result of the cooperating contours of the elements with the associated grooves. As a result, conventional metallic moise, caused by vibration upon beating of the drum heads, is successfully eliminated.

Abstract: 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 non-rotatably 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.

Abstract: 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 non-rotatably 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.