Abstract: A mold guiding device includes a tube having a hole in an end thereof and a threaded recess is defined in an inner end of the hole. A positioning member and a first end of a sleeve are inserted in the hole in sequence. A rod extends through the passage of the sleeve and the central hole of the positioning member and is threadedly engaged with the threaded recess in the tube. The diameter is the same as the sleeve when the sleeve is positioned in still, and is movable when the diameter of the positioning member is smaller than the passage of the sleeve.

Abstract: A multi-helical ball sleeve structure includes a cylindrical ball sleeve formed with a plurality of through holes, and a plurality of balls each received in a respective one of the through holes. The through holes are arranged in an oblique and helical manner. Thus, the multi-helical ball sleeve structure can enhance the lifetime and increase the working efficiency.

Abstract: This invention provides a multiple spiral bearing steel ball sleeve. The steel ball sleeve is a hollow tube. On the tube wall are multiple through holes evenly distributed. The holes closely spaced from each other and arranged in inclined surface and in spiral lines. Steel balls are placed inside the holes, so the entire set of steel ball sleeve can withstand a reduced pressure to extend its service life.