Abstract: An improved shaft for mounting an article such as a core for roll paper is proposed. The shaft has a core shaft, a boss mounted on the core shaft, and a plurality of sliders mounted in axial grooves formed in the boss. The sliders are slidable axially to a position at which their outer edges extend above the boss surface and are pressed against the inner wall of the center hole of the article to be mounted to securely hold the article.

Abstract: An improved negative film carrier for a disc film adapted to be mounted on a handling board in a photographic printer in which images on negative films fitted into a number of film frames arranged along the periphery of the disc film in an equally spaced relation are printed one by one onto a photographic printing paper as the disc film is intermittently turned, said handling board including an exposure opening formed thereon through which light beam passes, is disclosed, wherein the improvement consists in that the negative film carrier essentially comprises a negative film mask plate serving as a base section for mounting the negative film carrier on the handling board, an exposure opening of said negative film mask plate being located in vertical alignment with the exposure opening of the handling board, a negative film mask holder adapted to be fitted on the negative film mask plate and including a negative film mask portion of which exposure opening is located in vertical alignment with the exposure open