Abstract: Self-leveling pad assemblies are described having novel backing disks, a cushion layer in contact with the backing disk and a skin covering the cushion and at least one surface of the backing disk. The novel backing disks have an outer collar and a channel at the collar's base about the collar's inner circumference that provides the disk with an enhanced flexing region. The outer collar provides sufficient support for the pad's sealing surface, maintains an even tension on the pad's skin, has sufficient flexibility to allow the pad's surface to conform to an imperfect tone hole and to seal with only a cursory leveling procedure and reduces the number of tears in the pad's skin resulting from repeated contacts with the tone hole and from fluctuations in the skin's moisture content.

Abstract: A sealing pad assembly for closure of a wind instrument's tone hole and device for containing and securing the pad assembly. The pad's felt backing provides a soft support over the sealing surface of the tone hole to minimize noise but has a firm outer and central regions to minimize deformation of the pad surface and damage from abrasive contacts and to optimize the instrument's tone. The pad cup and retainer are designed to allow the retainer to pivot when the pad is leveled. As a result, stress is relieved which could otherwise damage the pad's surface or cause the pad nut to break away from the pad cup.

Abstract: A tone hole pad comprises a rigid backing disc but having a bendable margin and has at one face a recess between inner and outer coaxial collars to accommodate a cushion ring. Stretched across the radial faces of the collars and backed by the cushion ring is a membrane or skin as a sealing surface means that folds around the periphery of the rigid backing disc and is secured at the opposite face and is limited to a ringlike area. The support of the skin in a limited ringlike area on concentric collars effects a stability to resist and minimizes shrinkage or expansion, under ambient conditions, of the sealing surface that causes leakage. The periphery of the backing disc in one form of the invention is grooved to accommodate a tool for bending or marginally deforming one side of the disc to close leakage gaps caused by uneven contact on the rim of a tone hole. In a preferred form of the invention a similar but grooveless disc is backed by a non-bendable rigid disc.