Abstract: An improved mandrel for use on a dual bobbin spindle apparatus, the mandrel being an expandable contractible cylindrical sleeve having a plurality of expansion members and at least one interstitial resilient member separating the expansion members, providing positive engagement of a plurality of reels or bobbins containing wound webs of flexible material.

Abstract: A flywheel device for use in a magnetic recording/reproducing unit or the like which device is simple in construction, and can be produced at low costs, and a method of making it. A capstan shaft is press-fitted in a hole formed in a central portion of a metal disk, and then a resin is filled on an outer peripheral portion and a central portion of the disk by outsert molding to form an outer peripheral resin portion and a central resin portion. The outer peripheral resin portion has a groove formed in an outer periphery thereof, and the central resin portion has gear portions.