Abstract: The present invention provides an apparatus for electrically and hydraulically driving a hydraulic cylinder, including a hydraulic pump rotatable in opposite directions, an electric motor for driving the hydraulic pump, a reservoir tank containing hydraulic fluid therein, and a servo-valve. The hydraulic cylinder makes fluid-communication at a head-sided hydraulic chamber with a first port of the hydraulic pump, and makes fluid-communication at a rod-sided hydraulic chamber with a second port of the hydraulic pump. The servo-valve allows ones of the head-sided hydraulic chamber and the rod-sided hydraulic chamber to make fluid-communication to the reservoir tank in accordance with a direction in which the hydraulic pump rotates, and varies a degree at which one of the head-sided hydraulic chamber and the rod-sided hydraulic chamber makes fluid-communication with the reservoir tank, to a designated degree.

Abstract: There is provided a hot melt applicator including (a) a nozzle opening, (b) a valve seat disposed upstream of the nozzle opening, (c) an empty chamber formed between the nozzle opening and the valve seat, (d) a valve body movable to the valve seat so that the valve seat is open or closed, and (e) a spring for biasing the valve body; and a pneumatically driven cylinder for driving the spring. The valve body is shaped to be a cone having an apex angle facing the nozzle opening, and the valve seat is formed with a tapered surface which is to make a contact with the cone. The tapered surface has an angle greater than the apex angle of the cone, and has a length of at least 1 mm. The hot melt applicator uses a pneumatically driven cylinder for driving the valve body to thereby compress the spring which in turn compresses the valve body, and thus, avoids the great resistance of hot melt with the spring used as a large capacity.

Abstract: There is provided a hot melt applicator including (a) a nozzle opening, (b) a valve seat disposed upstream of the nozzle opening, (c) an empty chamber formed between the nozzle opening and the valve seat, (d) a valve body movable to the valve seat so that the valve seat is open or closed, and (e) a spring for biasing the valve body; and a pneumatically driven cylinder for driving the spring. The valve body is shaped to be a cone having an apex angle facing the nozzle opening, and the valve seat is formed with a tapered surface which is to make a contact with the cone. The tapered surface has an angle greater than the apex angle of the cone, and has a length of at least 1 mm. The hot melt applicator uses a pneumatically driven cylinder for driving the valve body to thereby compress the spring which in turn compresses the valve body, and thus, avoids the great resistance of hot melt with the spring used as a large capacity.