Abstract: An impeller for a turbine includes an impeller body formed by alternately stacking and fixing two or more types of disk blades, a base plate, and a rotating shaft. A plurality of pressed vane sections projecting from one surface are formed on the base plate of each disk blade, and recessed spaces are formed in the pressed vane sections, respectively. The projecting rear sections of the pressed vane sections are affixed to the other surface of the base plate of the adjacent disk blade, and disposed in the recessed spaces of the pressed vane sections of the adjacent disk blade in the mutually crossing direction. A part of a working gas is moved in the recessed spaces, and moved forward in the rotating direction over the projecting rear sections.

Abstract: A laser positioner is located at a survey base point for projecting a geodetic design pattern depicting design working points onto a working face remote from the base point by use of a laser pattern projector, upon surveying an object route by use of a laser surveying unit. In tunneling operations for example, the design pattern is formed on the working face, so that boring of the holes for charging explosives in the working face can be performed without paint-marking on the working face.

Abstract: In laser surveying system has a laser measuring unit which is operable independently of a laser projector, a laser spot pattern is first determined by using the laser measuring unit and projected onto the working face of an object structure by driving the laser projector. While marking the working face with the laser spot pattern formed by the laser projector to execute the desired construction work, the laser measuring unit is turned toward a different measuring object so as to independently make other measurements. Thus, point marking and measurement on different objects can be rationally effected at one time.

Abstract: An automatic surveying apparatus for surveying a route in tunneling work, for example, by directing a laser beam from a laser device onto a screen of a moving target to form a laser spot on the screen and detecting the positional coordinates of the laser spot on the screen by means of an image pick-up camera to obtain the positional deviation of the target with high accuracy. The angular deflections of the target can also be measured by use of a target composed of two screens and two image pick-up cameras.