Abstract: An adjustable two layer cymbal structure is disclosed. An adjustable spring is added at a lower side of the rotary seat of the adjustable seat for resisting against the adjustable seat. The rotary seat is adjusted upwards conveniently, rapidly and easily, and thus a preferred sound effect is achieved. Therefore, the prior art copper cymbal frame can be installed with a two layer copper cymbal or a two layer copper cymbal and a single one copper cymbal.

Abstract: A tuning means for a stringed instrument having one or more strings comprising detection means to provide a signal in response to vibration of the or each string and actuating means to vary the tension of the or each string under the control of an analysis means in response to said signal.

Abstract: Disclosed is a muffler in which a helicoil member is installed in each conduit, through which refrigerant gas flows from or into an expansion chamber during reciprocating movements of a piston in a cylinder. The helicoil member has diverse twisted angles and diverse twisted shapes, and serves to divide pulsation of noise, generated during the reciprocating movements of the piston, into pulsation of different phases, and then to merge the divided pulsation together, while allowing the refrigerant gas to have the form of a vortex flow. As pulsation of noise generated during an operation of sucking refrigerant gas pass along different travel paths defined by the helicoil member, a mutual interference occurs between the pulsation respectively emerging from the travel paths of the helicoil member. Therefore, an increased offset effect for the pulsation of noise is obtained, which maximizes a noise attenuation effect.

Abstract: A musical drum 40 which utilizes a principle of physics to achieve an unequal tensioning of the upper head 20 and the lower head 36 without the need of physical attachments or piercing of the drum shell 24. The shell of the drum 24 remains suspended by shell's bearing edge 26, in contact only with the upper and lower heads 20 and 36 respectively. This allows the shell 24 of the drum to resonate freely and unencumbered by any attachments of hardware.

Abstract: A plate utilizable in a noise protection wall of fragile acrylic glass comprising a plurality of side by side synthetic monofilament plastic threads for embedded in and running along the plate for splinter binding on breakage of the glass wherein, at least one thread has a maximum deviation of 1 mm or more from a theoretical straight line connecting the ends of said thread.

Abstract: A muffler is provided for a marine propulsion system in which an initial portion causes a downward flow of exhaust gas and entrained water from an exhaust manifold. The transition section directs the exhaust gas toward an egress section which extends upwardly from the transition section. The various sections of the exhaust path can be configured to form one or more loops which define one or more water collection regions.

Abstract: A protective cover, comprising one or more specially cut and perforated pieces of leather and a means whereby said protective cover can be attached tightly to the body of a stringed musical instrument, such as a solid-bodied electric guitar, which affords substantial protection to the body and any eventual finish on the body of said instrument against such scratches, cracks, dents, wear and other damage as can occur during normal usage, handling and transportation of said instrument, such protection being more comprehensive than known existing protective covers for such instruments by virtue of the proposed cover enclosing the entire visible surface of the body of said instrument and which, furthermore, affords desirable visual and tactile aesthetic qualities said stringed musical instrument.

Abstract: In a tunable drum, a connector member in the drum is attached by cables to a tuning ring, and is threadedly coupled by a tuning linkage to a retaining member fixed to the drum. Rotation of the tuning linkage with respect to the drum moves the connector member longitudinally and, as a result, adjusts the tension of the drumhead. In one embodiment, a handle fixed to the tuning linkage is positioned to engage a complementary coupling in a drum stand when the drum is retained by the drum stand. In another embodiment, the complementary coupling is movable between an operative position in which the drum can be tuned by rotating it with respect to the stand, and inoperative position in which the drum can be placed in the stand without the handle engaging the complementary coupling.

Abstract: A monolithic earplug being compressible or deformable. The earplug is fabricated from an extruded, elastomeric thermoplastic in order that it may be rapidly and efficiently produced, and then the extrudate is cut at the die face, as it emerges therefrom, into discrete pieces to form earplugs having convex end portions and a skin extending over its entire outer surface.

Abstract: Percussions instruments, especially drums, consist of a ring-shaped hollow form covered with hide or a resonant skin on the top and bottom. The skins are arranged in such a way that they can vibrate freely. To do this, a flexible tensioning device is used, whereby the tension of said skins can be adjusted by the percussionist during play. A tubular body integrated into the edge of the support in the form of a closed ring-shaped body is thus provided. Said body can be moved towards or away from the hollow form or the outer wall thereof. The tubular ring rests against the percussive ring on the U-shaped supporting edge like a stop and acts upon the edge of the skin. When the periphery of the tubular hose is modified, the described movement and tensioning of the skin occurs.

Abstract: A neck for a stringed instrument and including a neck body, a fingerboard, and an adjusting device located in a groove provided between the neck body and the fingerboard for adjusting the neck curvature, with the adjusting device including a bar secured in two, spaced from each other anchoring points provided on or in the neck and capable of absorbing tensioning or compression forces applied by the bar upon changing of its operational length, and a curve element for holding the bar in a desired curved position and for changing the bar operational length.

Abstract: There is provided a musical instrument comprising a plurality of elongated tubular members operative to generate specific sounds when blown therethrough. Each instrument body also has two opposing sides having a first radially extending female connector and a second musical instrument male connector, whereby the plurality of tubular members may be maintained in a generally parallel axis assembly.

Abstract: A musical instrument stand such as a hi-hat stand is basically constructed by a pair of cymbals, a stand member, a foldable tripod containing three legs, a pedal frame, an operation rod, a return spring, a transmission member, a pedal, a heel and an interconnection member. Normally, the return spring applies resilience to the operation rod, a lower end of which is being pressed upwardly together with a front end of the pedal by means of the transmission member. In addition, the interconnection member is formed in a U-shape, in which a bent portion is fixed to the heel of the pedal while ends are detachably attached to feet of the pedal frame. For storage and transportation of the musical instrument stand, the ends of the interconnection member being elastically deformed are disconnected from the feet of the pedal frame. Herein, straight portions of the interconnection member are held by holders, which are U-shape channels projecting downwardly from a back surface of the pedal.

Abstract: A loudspeaker comprising a bending wave panel, an enclosure in which the bending wave panel is mounted to enclose one face of the panel, a compliant suspension between the panel and the enclosure by which the panel is supported in the enclosure, a vibration exciter attached to the panel to apply bending wave energy thereto, and an acoustic absorber in the enclosure to reduce standing waves in the enclosure, wherein the compliant suspension and the acoustic absorber are integral. A method of making such a loudspeaker is also disclosed.

Abstract: A second slot is provided in the longitudinally extending shaft of a teaching tool, such as the Pneumo Pro, which is longitudinally spaced apart from the first slot of the tool, for automatically aligning the quadrant, and thereby the propellers, longitudinally and laterally with respect to the first slot during assembly of the apparatus and retaining the propellers in that orientation during usage. The quadrant and support block are formed with flat portions or surfaces which can be received in the second slot to establish a fixed point of longitudinal reference and an intersecting surface to establish a fixed point of lateral or rotational reference with respect to the first slot.

Abstract: An acoustic guitar is broken down into a body, a neck and a head, and the neck and the head are differently finished, wherein a panel already coated with paint for bright finish is attached to an incomplete head formed at the heading end of the neck, which has been already treated with oil so that any mask is not required in the finishing work.

Abstract: A speaker cone assembly comprises a felted paper-type cone fabricated of a composite material and a molded surround. The composite cone material contains natural fibers and synthetic fibers, where the synthetic fibers are able to chemically bond to material of the surround, thereby forming an improved bond during the molding procedure by which the surround is formed and attached to the cone. The method of preparing the composite cone material includes formulating and refining the natural fibers, preferably before adding the synthetic fibers.

Abstract: A sound-absorbing duct structure for an intake system of an automotive internal combustion engine. The sound-absorbing duct structure comprises a duct defining thereinside a gas passage. A part of the duct is formed with a plurality of small holes. An expanded duct section is formed around the part of the duct. The expanded duct section defines therein an inside space which is in communication with the gas passage through the small holes. The inside space has a cross-sectional area larger than that of the gas passage. A sound-absorbing section is disposed in at least a part of the inside space of the first expanded duct section. The sound absorbing section includes a piezoelectric material exhibiting a piezoelectric effect, and an electrically conductive material in contact with the piezoelectric material.

Abstract: Device for controlling the porosity of a helical, flexible, sound-absorbing, air-conducting tube; the present patent relates to a device comprised of a variable-width, non-porous film strip (2) helically arranged in a discontinued manner between the external layer or lining (1), formed of a helical strip of porous material (1-A) and the inner, cylindrical layer or lining (3), formed of a helical strip of porous material (3A0 of a flexible, cylindrical tube, the film strip (2) being intended to control the porous strips (5) of the tube wall and determining, by reason of the width of said film strip (2), a non porous strip (4) on the tube wall, with a consequent control of the acoustic attenuation.

Abstract: An earphone assembly is disclosed that includes an annular baffle having an outer surface and an inner surface as well as an interior wall and an exterior wall. The interior wall defines a central chamber. A transparent, flexible lid is attached to the baffle along the outer surface, completely covering the central chamber and forming an acoustic seal with the baffle. The lid has an inner face and an outer face. The flexibility of the earphone is improved by creating hinges in the lid and by providing cuts, or other discontinuities, in the baffle. For example, a radial cut may be disposed in the annular baffle. Further, a circumferential cut may also (or alternatively) be disposed in the baffle, extending from the inner surface and disposed between the exterior wall and the interior wall. At least one hinge may be disposed on the flexible lid. To improve the attachment of the earphone to the patient's head, tabs are mounted to the exterior wall.