Abstract: A pump unit includes a piezoelectric pump and a housing accommodating the piezoelectric pump. The piezoelectric pump includes a piezoelectric device having a through-hole, a first elastic plate covering an end of the through-hole, and a second elastic plate covering another end of the through-hole. The first elastic plate has a communication hole communicating with the through-hole of the piezoelectric device.

Abstract: An acoustic generator includes: a bimorph piezoelectric element including a stack of a plurality of internal electrodes and a plurality of piezoelectric layers, the bimorph piezoelectric element having a first main face and a second main face opposite the first main face; and a vibration plate joined to the second main face of the bimorph piezoelectric element. The bimorph piezoelectric element includes a region in a side of a first main face and a region in a side of a second main face, and, the plurality of piezoelectric layers constituting the region in the side of the first main face and the plurality of piezoelectric layers constituting the region in the side of the second main face are different from each other in at least one of relative permittivity and density.

Abstract: An acoustic generator includes: a bimorph piezoelectric element including a stack of a plurality of internal electrodes and a plurality of piezoelectric layers, the bimorph piezoelectric element having a first main face and a second main face opposite the first main face; and a vibration plate joined to the second main face of the bimorph piezoelectric element. The bimorph piezoelectric element includes a region in a side of a first main face and a region in a side of a second main face, and, the plurality of piezoelectric layers constituting the region in the side of the first main face and the plurality of piezoelectric layers constituting the region in the side of the second main face are different from each other in at least one of relative permittivity and density.

Abstract: Disclosed here is a color-image forming apparatus that minimizes damage caused by friction between a photosensitive drum and an inter-stage transfer belt. The apparatus includes a plurality of image-forming units, each of which has the photosensitive drum carrying an electrostatic latent image thereon, a developing unit forming a toner image by applying toner to the latent image. Having different color toners therein, the image-forming units are organized into a tandem layout. The inter-stage transfer belt is looped over plural rollers to form an endless path. While traveling the path along the direction in which the image-forming units are arranged, the belt forms a full-color toner image thereon by transferring plural toner-images on the drums one upon another. The belt is controlled to come into contact with the drums only while accepting the toner image from the drums.

Abstract: Disclosed here is a color-image forming apparatus that minimizes damage caused by friction between a photosensitive drum and an inter-stage transfer belt. The apparatus includes a plurality of image-forming units, each of which has the photosensitive drum carrying an electrostatic latent image thereon, a developing unit forming a toner image by applying toner to the latent image. Having separately different color toner therein, each image-forming unit is organized into a tandem layout. The inter-stage transfer belt is looped over plural rollers on its way of the endless path. While traveling the path along in the direction that the image-forming units are arranged, the belt forms a full-color toner image thereon by transferring plural toner-images on the drums one upon another. The belt is controlled to come into contact with the drums only while accepting the toner image from the drums.

Abstract: A method of producing a reinforced rubber hose, including the steps of continuously extruding a long plastic mandrel from a plastic material and feeding the extruded plastic mandrel, extruding an unvulcanized inner rubber tube on the long plastic mandrel, forming a tubular reinforcing layer on the unvulcanized inner rubber tube, extruding an unvulcanized outer rubber tube on the tubular reinforcing layer, vulcanizing the unvulcanized rubber tubes, thereby preparing a long rubber hose formed on the long plastic mandrel, cutting the long rubber hose into short rubber hoses having a predetermined length, while concurrently cutting the long plastic mandrel into short plastic mandrels, removing the short plastic mandrels from the short rubber hoses, and crushing the short plastic mandrels into a starting form of the plastic material, and returning the starting form of the plastic material to an extruder for continuously extruding the long plastic mandrel.

Abstract: Method and apparatus for producing a fiber-reinforced rubber hose having an inner rubber tube, a tubular reinforcing fiber layer, an outer rubber tube, and a resin cover tube, which are formed in this order on a core mandrel. After the formed cover tube is cooled to a temperature sufficiently low to harden the resin to an extent that substantially inhibits expansion of the outer rubber tube in the hardened cover tube, the unvulcanized inner and outer rubber tubes are microwave-heated to soften the rubber tubes, and to cause a thermal shrinkage of the tubular reinforcing fiber layer, for thereby causing a portion of the inner rubber tube to be forced through a network of an interlaced structure of the reinforcing fiber layer into the outer rubber tube. After the unvulcanized inner and outer rubber tubes are vulcanized, the resin cover tube is removed, and the fiber-reinforced rubber hose is prepared.