Abstract: An abrasive blasting apparatus comprising: supply means for supplying abrasive particles, and a rotatable impeller for blasting the abrasive particles supplied from this abrasive supply means onto a workpiece, the impeller having a plurality of vanes arranged in mutually spaced relationship around a rotation axis of the impeller, each of the vanes having a surface containing a first axis inclined with an angle of 25.degree.-65.degree. relative to said rotation axis and a second axis inclined with an angle of 40.degree.-80.degree.

Abstract: A heat engine having a cold compression space, a hot expansion space, a first passage connecting the two spaces through an externally heated heater and a second passage connecting the two spaces independently of the first passage through an externally cooled cooler. Preferably with the provision of intake and discharge valves, the two passages are arranged such that a working gas confined in the engine is passed from the compression space to the expansion space through the first passage and then returned to the compression space through the second passage. The engine may be combined with a gas reservoir which is equipped with valves and connected to the passages at low temperature sections for controlling the engine power by varying the mass of the working gas confined in the engine.

Abstract: A centrifugal blasting apparatus with a spindle arranged vertically, a boss fixed to the spindle, and a plurality of vanes provided circumferentially on the boss. The vanes are slanting with respect to the axis of rotation and an axis perpendicular to the axis of rotation. The apparatus throws abrasive particles in the axial direction permitting minimal size.

Abstract: A centrifugal blasting apparatus including an improved blast wheel and an improved deflector. The blast wheel comprises a flat disk and a plurality of vanes attached to the disk and spaced equiangularly from each other. Each of the vanes is composed of a first face having a substantially right-angled triangle configuration and a second face of substantially triangular configuration. The second face extends from the hypotenuse of the first face farther off the axis of rotation of the blast wheel than the first face and slants laterally and backwards with respect to the direction of rotation of the blast wheel. The deflector has a feed slot extending through the peripheral wall thereof. The feed slot is substantially parallelogram shaped. Such a blasting apparatus can present a regular and widened blast pattern having a uniform distribution of abrasive particles, thereby giving a desirable even processing to the workpiece.