| 摘要 |
937,642. Magnetic recording &c. heads, supporting. NORTH AMERICAN AVIATION Inc. July 15, 1960 [Aug. 3, 1959], No. 24708/60. Class 40 (2). Data storage apparatus comprises a disc having magnetizable media on both sides and rotatably mounted on a shaft extending between two headplates, each of said headplates having at least one magnetic head disposed therein. As described, an aluminium disc 1 is rotatably mounted on a shaft 5, the clearance between bearing surfaces 3, 4 on the disc and shaft forming an air bearing. The disc 1 is rotated by an electric motor comprising a stator 7 and rotor rings 6 on the disc 1 and has magnetizable annular surfaces 8, 9 adapted to co-operate with recording heads 13-16 on headplates 11, 12. The gaps between the disc 1 and the plates 11, 12 are adapted to form air thrust bearings and the plates 11, 12 are secured to the shaft 5 by flexible diaphragms 20, 21. The plates 11, 12 are provided with troughs 26 and grooves 35, Fig. 2, the grooves 35 extending beyond the circumference of the faces 8, 9 of the disc 1 so as to allow air to be drawn into the bearing area. The troughs 26 may be of uniform depth or may have stepped surfaces (Figs. 3, 4, not shown). Fig. 7 shows a read head comprising a high permeability polepiece 52 of three laminations, the opposite limbs 53, 54 of the polepiece being held between sections 56, 57 of ferrite material having a hollow centre 58 filled with a plastic dielectric material such as an epoxy resin mixed with aluminium oxide powder, this material providing rigidity. The write head (Fig. 6, not shown), is of similar construction. The electric circuit for the write head may comprise a centre-tapped coil the ends of which are connected to driver tubes (Fig. 8, not shown). In the read head, one end of the coil is earthed and the other end is connected to the grid of a detector tube (Fig. 9, not shown). Specification 929,878 is referred to. |
