Abstract: A rotatable rod includes a plurality of cylindrical center rods and a plurality of joints. Each joint connects between corresponding two of the plurality of center rods. Each of opposed ends of each center rod has at least one engaging projection, which projects from the end of the center rod in a direction parallel to an axial direction of the center rod. Each of opposed ends of each joint has at least one engaging recess, each of which is engaged with a corresponding one of the at least one engaging projection that is provided in an adjacent one of the ends of a corresponding one of the plurality of center rods.

Abstract: A stator includes first and second piezoelectric elements, a flexible aluminum-based connective arrangement and upper and lower aluminum-based metal blocks. The flexible aluminum-based connective arrangement includes first to fourth aluminum-based electrodes, which apply a voltage to the piezoelectric elements to generate a vibration. Each aluminum-based electrode is made of one of aluminum and an aluminum alloy and directly contacts a corresponding one of axial ends of the piezoelectric elements. Each aluminum-based metal block is made of one of aluminum and an aluminum alloy. The piezoelectric elements and the aluminum-based electrodes are interposed between the aluminum-based metal blocks.

Abstract: An electric curtain device of the present invention includes a pair of running members and a pair of chargers arranged at opposed ends of a curtain rail. The running members are movable along the curtain rail and support a pair of curtains, respectively, in a suspended state. Each of the running members includes a supersonic motor and is moved along the curtain rail when actuated by a supersonic motor. Further, each running member has a battery and a driver. The electric curtain device is relatively easy to handle. Further, the appearance of the device is improved without requiring machining of the curtain rail.

Abstract: A lower metal block of a stator includes a plurality of securing projections, which engage with an external member and are arranged in an outer peripheral surface of the lower metal block at generally equal angular intervals. Each securing projection is circumferentially located between corresponding two of slits of the lower metal block and has first and second axial ends, which are opposed to one another in a direction generally parallel to the axial direction of the stator and are oriented toward first and second axial ends, respectively, of the stator. The first axial end of each securing projection is axially positioned within an axial extent of the slits, which is measured in the axial direction of the stator.

Abstract: A rotatable rod includes a plurality of cylindrical center rods and a plurality of joints. Each joint connects between corresponding two of the plurality of center rods. Each of opposed ends of each center rod has at least one engaging projection, which projects from the end of the center rod in a direction parallel to an axial direction of the center rod. Each of opposed ends of each joint has at least one engaging recess, each of which is engaged with a corresponding one of the at least one engaging projection that is provided in an adjacent one of the ends of a corresponding one of the plurality of center rods.

Abstract: A yoke housing accommodates an armature having a coil and has a tubular circumferential wall. The yoke housing includes a plurality of pieces, which form the yoke housing, and a fracture portion, which is located along a boundary between the pieces. The fracture portion fractures when a compression force is applied from the outside to break the yoke housing into the pieces.

Abstract: An armature includes a rotary shaft, a core, and a coupling member. The core is formed by using magnetic metal powder and has a tooth. A wire is wound about the tooth. The coupling member has a ductility that is higher than the ductility of the core. The coupling member is located between the core and the rotary shaft. The rotary shaft is press fitted in the coupling member, and the coupling member is press fitted in the core.

Abstract: A stator includes first and second piezoelectric elements, a flexible aluminum-based connective arrangement and upper and lower aluminum-based metal blocks. The flexible aluminum-based connective arrangement includes first to fourth aluminum-based electrodes, which apply a voltage to the piezoelectric elements to generate a vibration. Each aluminum-based electrode is made of one of aluminum and an aluminum alloy and directly contacts a corresponding one of axial ends of the piezoelectric elements. Each aluminum-based metal block is made of one of aluminum and an aluminum alloy. The piezoelectric elements and the aluminum-based electrodes are interposed between the aluminum-based metal blocks.

Abstract: A lower metal block of a stator includes a plurality of securing projections, which engage with an external member and are arranged in an outer peripheral surface of the lower metal block at generally equal angular intervals. Each securing projection is circumferentially located between corresponding two of slits of the lower metal block and has first and second axial ends, which are opposed to one another in a direction generally parallel to the axial direction of the stator and are oriented toward first and second axial ends, respectively, of the stator. The first axial end of each securing projection is axially positioned within an axial extent of the slits, which is measured in the axial direction of the stator.

Abstract: A yoke housing accommodates an armature having a coil and has a tubular circumferential wall. The yoke housing includes a plurality of pieces, which form the yoke housing, and a fracture portion, which is located along a boundary between the pieces. The fracture portion fractures when a compression force is applied from the outside to break the yoke housing into the pieces.

Abstract: An ultrasonic motor has a stator and a rotor which is press fit to the stator and rotates in accordance with the vibration of the stator. The stator includes a pair of metal blocks, a piezoelectric element located between the metal blocks, a tightening member and a positioning member. The tightening member is inserted through the metal blocks and the piezoelectric element to tighten the metal blocks and the piezoelectric element in the axial direction. The positioning member determines the radial position of the metal blocks. This reduces misalignment of metal blocks and the tightening member, and the stator for the ultrasonic motor.

Abstract: A clutch mechanism is provided between a driving rotor and a driven rotor. The clutch mechanism selects from a state for transmitting rotational force and a state for discontinuing the transmission of rotational force. The holder permits the rolling. A holder supports rolling bodies such that the rolling bodies are switched between a transmitting position and a disconnecting position. When held at the transmitting position, the rolling bodies are engaged with both of the driving rotor and the driven rotor so that rotational force of the driving rotor is transmitted to the driven rotor. When held at the disconnecting position, the rolling bodies are disengaged from the driving rotor so that the transmission of rotational force from the driven rotor to the driving rotor is discontinued. When external rotational force is applied to the driven rotor, the holder sets the rolling bodies to the disconnecting position.

Abstract: An armature includes a rotary shaft, a core, and a coupling member. The core is formed by using magnetic metal powder and has a tooth. A wire is wound about the tooth. The coupling member has a ductility that is higher than the ductility of the core. The coupling member is located between the core and the rotary shaft. The rotary shaft is press fitted in the coupling member, and the coupling member is press fitted in the core.

Abstract: An ultrasonic motor has a stator and a rotor which is press fit to the stator and rotates in accordance with the vibration of the stator. The stator includes a pair of metal blocks, a piezoelectric element located between the metal blocks, a tightening member and a positioning member. The tightening member is inserted through the metal blocks and the piezoelectric element to tighten the metal blocks and the piezoelectric element in the axial direction. The positioning member determines the radial position of the metal blocks. This reduces misalignment of metal blocks and the tightening member, and the stator for the ultrasonic motor.

Abstract: An ultrasonic motor includes a stator and a rotor. A plurality of slits are arranged at substantially equal angular intervals along an outer peripheral surface of the rotor. A photosensor is supported inside of an upper housing of the motor. The photosensor is arranged to oppose each one of the slits in a radial direction of the rotor when the slit comes in front of the photosensor during rotation of the rotor. Based on a signal outputted from the photosensor, a control device applies a high frequency alternating voltage between first and second electrode plates of the stator.

Abstract: A clutch mechanism is provided between a driving rotor and a driven rotor. The clutch mechanism selects from a state for transmitting rotational force of the driving rotor to the driven rotor and a state for discontinuing the transmission of rotational force generated from the driven rotor to the driving rotor. A plurality of rolling bodies is located between the driving rotor and the driven rotor. A holder holds the rolling bodies. The holder permits the rolling bodies to roll. The holder supports the rolling bodies such that the rolling bodies are switched between a transmitting position and a disconnecting position. When held at the transmitting position, the rolling bodies are engaged with both of the driving rotor and the driven rotor so that rotational force of the driving rotor is transmitted to the driven rotor.

Abstract: A stator includes a longitudinal-vibration sensing electrode. The stator also includes a torsional-vibration sensing piezoelectric element and a torsional-vibration sensing electrode plate for sensing torsional vibrations. A voltage signal from the torsional-vibration sensing electrode plate or a voltage signal from the longitudinal-vibration sensing electrode is sensed. Then, a drive voltage signal for driving the stator is generated in a self-excited oscillation drive circuit in such a manner that an actual vibrational frequency of the stator substantially coincides with a resonance frequency. Thereafter, the generated drive voltage signal is applied between a drive electrode and each one of first and second electrode plates.

Abstract: An ultrasonic motor includes a stator and a rotor. A plurality of slits are arranged at substantially equal angular intervals along an outer peripheral surface of the rotor. A photosensor is supported inside of an upper housing of the motor. The photosensor is arranged to oppose each one of the slits in a radial direction of the rotor when the slit comes in front of the photosensor during rotation of the rotor. Based on a signal outputted from the photosensor, a control device applies a high frequency alternating voltage between first and second electrode plates of the stator.

Abstract: A stator includes a longitudinal-vibration sensing electrode. The stator also includes a torsional-vibration sensing piezoelectric element and a torsional-vibration sensing electrode plate for sensing torsional vibrations. A voltage signal from the torsional-vibration sensing electrode plate or a voltage signal from the longitudinal-vibration sensing electrode is sensed. Then, a drive voltage signal for driving the stator is generated in a self-excited oscillation drive circuit in such a manner that an actual vibrational frequency of the stator substantially coincides with a resonance frequency. Thereafter, the generated drive voltage signal is applied between a drive electrode and each one of first and second electrode plates.

Abstract: An ultrasonic motor composed of a cylindrical stator having a vibration converting member and a cylindrical rotor slidably rotatable on the stator. Ultrasonic longitudinal vibration is generated in the stator by imposing high frequency voltage on piezoelectric elements disposed in the stator. A part of the longitudinal vibration is converted into twisting vibration by operation of slits formed on the vibration converting member. Both the longitudinal and twisting vibrations are compounded into elliptic vibration which drives the rotor. The vibration converting member is made by laminating a number of element plates each having cut-out portions or by combining several divided blocks. The slits are automatically formed on the vibration converting member without being machined, when the vibration converting member is formed by assembling the element plates or the divided blocks.