Abstract: A percussion instrument includes: a cylindrical shell portion having an open upper surface side; and a drumhead stretched to be installed on the upper surface side of the shell portion, wherein the drumhead includes: a membrane formed of a membranous material, having a struck head portion configured as a striking face to be struck by a performer and an outer periphery located on an outer circumferential side of the struck head portion; and an annular frame formed of a resin material and having the outer periphery of the membrane fixed thereto, and the drumhead is integrally formed by the membrane and the frame by injection molding.

Abstract: A drum includes a fixing means for fixing an edge portion of the membrane member; an interval forming means for forming an interval between the edge portion, fixed by the fixing means, and the striking surface of the membrane member in a normal direction of a plane of the striking surface; and contact members in contact with a connection portion of the membrane member, which connects the edge portion and the striking surface. The contact members contact the connection portion respectively at different positions along a circumferential direction of the connection portion. The contact members are in contact with an inner side of the tension ring and are displaced toward a center of the striking surface as the diameter of the circle surrounded by the tension ring is reduced.

Abstract: An electronic cymbal includes a disk-shaped main body portion and a striking sensor. A covering member is provided to cover an outer circumferential edge portion of the main body portion and includes an upper covering portion covering an upper surface side of the main body portion, an extending portion extending further toward an outer circumferential side than the outer circumferential edge portion of the main body portion, a lower covering portion covering a lower surface side of the main body portion. The striking sensor at least includes an edge sensor between the lower surface of the main body portion and the lower covering portion, and by pressing down the extending portion, the lower covering portion is elastically deformed in a direction toward the main body portion to sandwich the edge sensor with the lower covering portion and the main body portion and press the edge sensor.

Abstract: A tool main spindle, whose cutting angle can be changed, is translated by an X-axis moving mechanism portion on an X-axis provided in a plane perpendicular to an axis of a work; and is translated on a Y-axis by a Y-axis moving mechanism portion. Cutting of the work is performed by setting the cutting angle of the tool main spindle to an angle of the cutting tool at which the work has large dynamic rigidity, and causing an axis of a cutting tool to cross the work axis, and cutting the work with the cutting tool toward the axis of the work by cooperatively operating the X-axis moving mechanism portion and the Y-axis moving mechanism portion.

Abstract: A tool-main-spindle, whose cutting angle can be changed, is translated by an X-axis moving mechanism portion on an X-axis provided in a plane perpendicular to an axis of a work, and is translated on a Y-axis by a Y-axis moving mechanism portion. Cutting of the work is performed by setting the cutting angle of the tool-main-spindle to an angle of the cutting tool at which the work has large dynamic rigidity, and causing an axis of a cutting tool to cross the work axis, and cutting the work with the cutting tool toward the axis of the work by cooperatively operating the X-axis moving mechanism portion and the Y-axis moving mechanism portion.

Abstract: A cymbal is provided with an annular part having an annular shape and having a predetermined rigidity, a center part located at an inner circumference of the annular part and having a predetermined rigidity, and a first connecting part including an elastic material and connecting an outer circumference of the center part and the inner circumference of the annular part.

Abstract: A machine tool includes a number-of-same-rotation-speed-cutting-passes computing section that decides the number of same rotation speed cutting passes. The number-of-same-rotation-speed-cutting-passes computing section determines the cutting mode of a threading process based on a set machining program etc., and automatically decides an optimal number of same rotation speed cutting passes according to the cutting mode. Thus, even unskilled operators can easily suppress chatter vibrations, and can easily use the machine tool.

Abstract: A chatter vibration suppressing method includes acquiring a moment of inertia of a rotating body, recording a value indicating the acquired moment of inertia into a machining program, and calculating a variable amplitude and a variable period when a rotation speed of the rotating body is varied in order to suppress chatter vibration from the value indicating the moment of inertia recorded in the machining program and the maximum input power of a motor for rotating the rotating body.

Abstract: A vibration suppressing device includes a memory unit storing a stable rotation speed calculated by an arithmetical unit in association with a rotation speed range that includes the stable rotation speed, in which, when a command rotation speed that is a rotation speed of a rotary shaft is inputted in starting machining operation by rotation of the rotary shaft and, the arithmetical unit determines whether the command rotation speed is included in the rotation speed range or not, reads out the stable rotation speed when the command rotation speed is included in the rotation speed range and outputs the stable rotation speed to an NC device instead of the command rotation speed, and starts the machining operation at the stable rotation speed.

Abstract: A cymbal silencer reduces a percussive sound of a cymbal by abutting the cymbal silencer against the cymbal. The cymbal silencer includes a frame having an inner part, a connecting part and an outer part, and a first elastic member. The inner part has an insertion hole into which a bar-shaped rod for fixing the cymbal is inserted. One side of the connecting part is connected to the inner part and extends toward a direction away from the insertion hole. The outer part is connected to the other side of the connecting part and is disposed at a position further away from the insertion hole than the one side of the connecting part. The outer part corresponds to the bow portion of the cymbal. The first elastic member is installed on one surface side of the outer part of the frame and is composed of the first elastic material.

Abstract: A drum head having a striking feeling similar to an acoustic drum includes an inner head layer and a pair of outer head layers. The outside diameter of the inner head layer is smaller than the outside diameter of a flat part of the outer head layers and the inside diameter of the edge of the shell. The inner head layer is inside the connection part between the flat part and a cylindrical part of the outer head layers and the shell edge part. When tension is applied to the outer head layers, tension is prevented from being applied to the inner head layer.

Abstract: When a rotation speed is fluctuated, a fluctuation diagram showing the relationship between a fluctuation amplitude and a fluctuation period of the rotation speed is displayed on a monitor. In addition to a current setting value, a settable range of the fluctuation amplitude and the fluctuation period is displayed on the fluctuation diagram. At least one of an optimal fluctuation period PO based on Equation (1) below and an optimal range P1 of the fluctuation period based on Equation (2) below is also displayed on the fluctuation diagram, wherein T is a rotation period of a rotary shaft, and a, amin, amax are preset coefficients.

Abstract: A pedal apparatus that suppress the generation of acoustic sound at the time of operation includes a belt member made of an elastic material linked to an upright section of a main body section and a belt fastening section of a pedal. When the pedal is stepped on by a performer, the belt member is tensioned from a relaxed state and displaced to a linear form while being subjected to elastic deformation. When the pedal is further stepped on from that state, the displacement of the pedal is limited by the tensile force of the belt member. Accordingly, the generation of the striking sound that would otherwise be produced due to the impacting of bodies against each other to limit the pedal displacement can be avoided.

Abstract: A percussion instrument is configured for minimizing space used for set up for use. The percussion instrument uses a belt member stretched between one of two upper stretching members and a lower stretching member, to form a striking surface. By using the elasticity of the belt member, the striking surface can simulate the tension sensation of a conventional acoustic percussion instrument. By forming the belt member in a band shape, the width dimensions of the striking surface can be small relative to conventional circular shaped striking surfaces.

Abstract: A percussion instrument may have a hoop member configured to hold down a head stretched across a first end of the shell by a plurality of adjustment devices that may be for operatively connecting the hoop member with a plurality of fixtures that may be arrangeable along at least two surfaces of the shell.

Abstract: In a machine tool which includes a rotary shaft configured to allow a tool or a workpiece to be attached thereto, a driving unit for causing the rotary shaft to rotate is regulated to change a rotation speed of the rotary shaft in such a manner that the rotation speed oscillates with a given amplitude and a given period with respect to a given mean rotation speed, so that chatter vibrations can be suppressed. A parameter display control unit configured to cause a display device to display parameter information related to predetermined parameters for changing at least one of the mean rotation speed, the amplitude and the period is provided so that the parameters can be changed based upon the parameter information displayed in the display device.

Abstract: In suppressing chatter vibration of a rotary shaft in a machine tool by fluctuating rotation speed of the rotary shaft, easy setting of a fluctuation parameter is realized. In a monitor apparatus of the machine tool, a graph showing a fluctuation amplitude of the rotation speed is displayed. On this graph, a current fluctuation position (first point) is indicated by a black circle marker, and also, a power limit line L of a motor fluctuation period is depicted based on a predetermined equation. In an area not exceeding the power limit line L, a new fluctuation position (second point) having a larger fluctuation amplitude and a shorter fluctuation period than the current fluctuation position is calculated and indicated with an arrow A guiding this new point from the current fluctuation position.

Abstract: A vibration suppressing device includes a memory unit storing a stable rotation speed calculated by an arithmetical unit in association with a rotation speed range that includes the stable rotation speed, in which, when a command rotation speed that is a rotation speed of a rotary shaft is inputted in starting machining operation by rotation of the rotary shaft and, the arithmetical unit determines whether the command rotation speed is included in the rotation speed range or not, reads out the stable rotation speed when the command rotation speed is included in the rotation speed range and outputs the stable rotation speed to an NC device instead of the command rotation speed, and starts the machining operation at the stable rotation speed.

Abstract: A pedal apparatus that suppress the generation of acoustic sound at the time of operation includes a belt member made of an elastic material linked to an upright section of a main body section and a belt fastening section of a pedal. When the pedal is stepped on by a performer, the belt member is tensioned from a relaxed state and displaced to a linear form while being subjected to elastic deformation. When the pedal is further stepped on from that state, the displacement of the pedal is limited by the tensile force of the belt member. Accordingly, the generation of the striking sound that would otherwise be produced due to the impacting of bodies against each other to limit the pedal displacement can be avoided.

Abstract: A percussion instrument is configured for minimizing space used for set up for use. The percussion instrument uses a belt member stretched between one of two upper stretching members and a lower stretching member, to form a striking surface. By using the elasticity of the belt member, the striking surface can simulate the tension sensation of a conventional acoustic percussion instrument. By forming the belt member in a band shape, the width dimensions of the striking surface can be small relative to conventional circular shaped striking surfaces.