Abstract: A composite longitudinal vibration mechanical filter for delivering out a supplied high-frequency signal in a predetermined frequency range includes a plurality of vibratable bodies including input and output longitudinal vibratable tuning bars with piezoelectric members superposed thereon, coupling elements by which the longitudinally vibratable tuning bars are coupled to each other, supporting elements projecting respectively from the input and output longitudinally vibratable tuning bars, and a holder to which the supporting elements are attached. At least one resonant frequency adjusting finger is disposed on at least one of the vibrational bodies. Grooves are defined in the longitudinally vibratable tuning bars at the same time that they are fabricated. The grooves extend in the direction in which the longitudinally vibratable tuning bars are longitudinally vibratable, and are shorter than the length of the longitudinally vibratable tuning bars.

Abstract: A method of manufacturing a composite longitudinal vibration mechanical filter that vibrates at a preselected central frequency in a high frequency range. The filter includes a plurality of vibratable bodies including input and output vibratable bodies each having respective piezoelectric members superposed thereon. Coupling elements couple the vibratable bodies to each other. Supporting elements project respectively from the input and output vibratable bodies. A holder is provided to which the supporting elements are attached. The method includes forming an integral body including the plurality of vibratable bodies, the coupling elements, the supporting elements, the holder and a vibration absorbing body holder for eliminating unnecessary vibrations.

Abstract: A motorcycle having a secondary air supply for delivering air to the exhaust ports of the engine for assisting in exhaust treatment of the exhaust gases. Air is supplied through reed-type check valves which are positioned in a concealed portion of the motorcycle body for silencing noise. The conduit which connects the check valves to the exhaust ports extends vertically downwardly substantially throughout its length so that condensed liquids in the conduit will pass back to the exhaust port rather than accumulate in the conduit.

Abstract: A composite longitudinal vibration mechanical filter for delivering out a supplied high-frequency signal in a predetermined frequency range includes a plurality of vibratable bodies including input and output longitudinal vibratable tuning bars with piezoelectric members superposed thereon, coupling elements by which the longitudinally vibratable tuning bars are coupled to each other, supporting elements projecting respectively from the input and output longitudinally vibratable tuning bars, and a holder to which the supporting elements are attached. At least one resonant frequency adjusting finger is disposed on at least one of the vibratable bodies. Grooves are defined in the longitudinally vibratable tuning bars at the same time that they are fabricated. The grooves extend in the direction in which the longitudinally vibratable tuning bars are longitudinally vibratable, and are shorter than the length of the longitudinally vibratable tuning bars.

Abstract: A surface acoustic wave device has a package and a surface acoustic wave element mounted therein face down. The package includes a side wall comprising linear inner side surfaces close to respective outer side surfaces of the surface acoustic wave element and recesses defined where the inner side surfaces of the side wall intersect at respective inner corners. When the surface acoustic wave element is inserted into the side wall along the inner side surfaces thereof, the corners of the surface acoustic wave element do not engage the side wall because of the recesses. Therefore, the outer side surfaces of the surface acoustic wave element may be positioned very closely to the inner side surfaces of the side wall. The surface acoustic wave device may be reduced in size, and the surface acoustic wave element may have input and output electrode pads and ground pads positioned highly accurately with respect to electrode pads on the bottom plate of the package.

Abstract: A composite longitudinal vibration mechanical filter for delivering out a supplied high-frequency signal in a predetermined frequency range includes a plurality of vibratable bodies including input and output longitudinal vibratable tuning bars with piezoelectric members superposed thereon, coupling elements by which the longitudinally vibratable tuning bars are coupled to each other, supporting elements projecting respectively from the input and output longitudinally vibratable tuning bars, and a holder to which the supporting elements are attached. Grooves are defined in the longitudinally vibratable tuning bars at the same time that they are fabricated. The grooves extend in the direction in which the longitudinally vibratable tuning bars are longitudinally vibratable, and are shorter than the length of the longitudinally vibratable tuning bars.

Abstract: A surface elastic wave filter includes a plurality of input interdigital transducers for receiving a high-frequency input signal, and a plurality of output inter-digital transducers for producing an output signal derived from the input signal and having predetermined frequency characteristics. Each of the input and output interdigital transducers having a pair of confronting connectors for receiving the input signal and extracting the output signal, respectively, and a pair of groups of interdigitating electrode fingers extending from the connectors. The input and/or output interdigital transducers include finger-withdrawn interdigital transducers with electrode fingers selectively withdrawn in different positions. With such withdrawal weighting, the interdigital transducers have different sidelobe characteristics, i.e., frequency blocking characteristics, so that the surface elastic wave filter operates with a greater sidelobe suppression.

Abstract: A surface elastic wave filter has a pair of electrodes on a surface of a piezoelectric body, and at least one of the electrodes is constructed as electrode fingers in the form of comb teeth which are progressively spread away from each other along a direction normal to the direction in which a surface elastic wave is propagated on the surface of the piezoelectric body. A grating or dot structure as a scattering reflector for scattering and reflecting a portion of the surface elastic wave is disposed in a desired position between the electrodes. Alternatively, some of electrode fingers of a surface elastic wave filter are dropped or removed, or divided voltages are applied to electrode fingers, or a scattering reflector is added to a filter with some of its electrode fingers removed or with divided voltages applied to electrode fingers. With such an arrangement, a filter having good selectivity and desired frequency characteristics can be achieved.

Abstract: In a process for preparing soft polyesters which comprises reacting (A) terephthalic acid and/or its ester-forming derivative, (B) tetramethylene glycol and/or its ester-forming derivative and (C) a poly(oxyalkylene) glycol having a molecular weight of 500 to 5,000 and a ratio of the number of carbon atoms to that of oxygen atoms of 2 to 4.5, the improvement wherein after the reduced viscosity of the reaction product of the components (A), (B) and (C) has reached 0.1 (dl/g), the reaction product is further reacted with (D) a low-molecular-weight ester compound and/or a high-molecular-weight ester compound containing a terephthalic acid residue and an ethylene glycol residue or a low-molecular-weight ester compound and/or a high-molecular-weight ester compound containing a terephthalic acid residue and a 1,4-cyclohexane dimethanol residue to form a polyester-polyether block copolymer.

Abstract: In a process for preparing a block copolyester elastomer having a softening point of at least 120.degree. C. by reacting an aromatic polyester (I) having a reduced viscosity of at least 0.4 and derived from an aromatic dicarboxylic acid or its ester-forming derivative as a main acid component with an aliphatic polyester (II) having a reduced viscosity of at least 0.4 and derived from an aliphatic dicarboxylic acid or an aliphatic hydroxycarboxylic acid or an ester-forming derivative of each of these acids in the molten state; the improvement whereinA. the aromatic polyester (I) is derived from a dicarboxylic acid component more than 70 mole % of which consists of terephthalic acid and diol component more than 70 mole % of which consists of tetramethylene glycol or trimethylene glycol,B. the weight ratio of the aromatic polyester (I) to the aliphatic polyester (II) is 0.25 to 9, andC.