Abstract: An apparatus for measuring tension of piston rings includes a cylindrical support fixture having a circumferential groove formed therearound for receiving and holding a piston ring. A rigid base supports a plurality of components of the apparatus. A strong, thin band, formed from a material sufficiently strong to withstand repeated applications of pulling force thereto, is mounted to the base, and is held between two clamps. The band has a loop formed therein, for receiving the support fixture with a piston ring mounted therein. The apparatus also includes reciprocally movable structure for tightening the band around the support fixture, such as a slidably movable clamp assembly at one end of the band. The apparatus further includes mechanism for measuring tension on the band, and fluid activatable mechanism for vertically reciprocating a portion of the support fixture. In a preferred embodiment, the reciprocating mechanism is pneumatically activatable, such as by compressed air.

Abstract: A disk wheel for a motor vehicle includes an inner rim portion and a disk portion which are formed integrally with each other. An outer rim portion which is independent of the inner rim portion and disk portion is rigidly fitted on the outer circumferential surface of the disk portion. The inner and outer rim portions are different in thickness from each other, so that the inner rim portion is provided with greater rigidity without increasing the overall weight of the disk wheel.

Abstract: The invention provides a novel method for manufacturing a knife-edge die for stamping out a metal foil on an insulating base plate such as in the preparation of an electronic circuit board by a technique of photoetching. The method comprises a line pattern of a photoresist film on the die face corresponding to the contour of the desired pattern, subjecting the die face to a first etching to effect substantial side etching behind the photoresist film to leave an edge, removing the photoresist film and subjecting the die face to a second etching to sharpen the edge into a knife edge.