Abstract: A mining riser pipe is extended from above water toward a water bottom containing water bottom resources, and a lower portion of an insertion pipe connected to a lower portion of the mining riser pipe is inserted into the water bottom. A liquid is supplied into the insertion pipe and a rotation shaft extends axially inside both of pipes is rotated to rotate stirring blades attached to a lower portion of the rotation shaft inside the insertion pipe, thereby drilling and dissolving mud S inside the insertion pipe into a slurry form is raised to an upper portion of the insertion pipe by a stirring flow generated by the rotation of the stirring blades, and the raised mud is lifted above the water through the mining riser pipe by lifting force.

Abstract: A direct-current motor includes a rotatable shaft, a core mounted on the rotatable shaft and supporting windings disposed around the core, the core having winding-free portions, a first drive magnet disposed in radially confronting relation to the winding-free portions with an air gap, and magnetized substantially perpendicularly to the rotatable shaft, and a second drive magnet disposed in axially confronting relation to the winding-free portions with an air gap, and magnetized substantially axially of the rotatable shaft.

Abstract: A process for fabricating a cup-shaped coreless armature by placing a cup-shaped armature winding and a component including a commutator for constituting the armature into a heating die assembly along with a molding resin member in the form of a solid at room temperature, clamping the die assembly to melt the resin member and thereafter curing the resin to unite the winding and the commutator into a rigid body with the resin.

Abstract: A cylindrical field magnet for use in small size d-c motors having a coreless armature. The magnet includes magnetic pole portions varying in wall thickness from the interpolar portions and possesses an increased quantity of magnetic flux in its entirety without an increase in its outside diameter.