Patent GB-1311563-A (GB)
Title: Hollow hubs
IPC: G06K13/22
Filed: 1970-06-16
Abstract: 1311563 Hubs; tape reels INTERNATIONAL COMPUTERS Ltd 19 April 1971 [16 June 1970] 29068/70 Heading B8M A hollow hub assembly 1 includes first and second hollow hub members 3, 4 each having a cylindrical external surface with the same diameter as the other, and each having an end surface extending inwardly from the associated cylindrical external surface, and means defining a plurality of spaced apart projections 8, 8a, extending axially from the end surface; the assembly including means, e.g. bosses 5, 5a, maintaining the members 3, 4 in fixed co-operation with each other such that the end surface face towards each other with the projections 8, 8a co-operating to produce a space or spaces 10 extending from the external surfaces to the hollow interior 11 of the assembly, whereby vacuum applied to the interior of the hub produces a suction effect at the cylindrical external surfaces, e.g. to attach the leading end of a tape to the hub. The projections 8, 8a may be of sinuous or castellated form and in a preferred embodiment, the projections 8, 8a are positioned centrally between the gaps 9a, 9, of the opposite hub member. If the projections are positioned off-centre, the width of the spaces 10 may be varied, and the number of spaces halved if the projections abut one side of the associated gap. If the projections 8 are shorter than the projections 8a, U-shaped or L-shaped spaces may be formed; and if the length of the projections on both hub members is insufficient to abut the bases of the gaps 9, 9a, a continuous space is formed. Each hub is formed with an annular side wall with a central aperture through which a driving shaft 7 may pass. Adjacent the central aperture the side wall is provided with an annular boss 5 having holes to receive locating pins 16. The bossed 5 of the two hub members mate to define the axial spacing of the members. Radially exterior of the boss 5 at least one of the hub members is provided with apertures 12a to connect the interior 11 of the hub to a source of vacuum. The side walls of the hub member may also be provided with upstanding annular locating flanges 13, 13a. If both side walls are provided with apertures 12, 12a, a cover-plate 20 is provided to maintain the vacuum within the interior of the hub. The shaft 7 is preferably secured by means of a knurled nut 18. In a preferred embodiment, the hub forms part of a tape reel and is provided with two side flanges 2, 2a. The hub is located on a base-plate 14 of an apparatus by means of the flange 13a and a flange 19 on the base-plate. The source of vacuum is applied via an annular passage 21 surrounding the shaft 7. The hollow hub may also be used, with the omission of the flanges as the capstan roller in magnetic tape apparatus. The hub may be made from thermoplastic or thermosetting material or light metal alloys. In a tape reel embodying the hub the flanges may be made of styrene : acrylonitrile resin and the hub of glass-filled acrylonitrile resin. Ultrasonic welding or adhesives may be used to secure the hub members together. The flanges may be made of different materials one from another or have a different finish for indication purposes.