(1) Field of the Invention
The present invention relates to a magnetic disc device used as a memory means for mini-computers or a micro-computers.
Conventionally, a Winchester type magnetic disc device using hard discs 3.5 inches in diameter has been used as a memory means for a mini-computers or a micro-computers. Such a magnetic disc devices must have a high memory density without any enlargement of the size thereof, to ensure that it is compatible with other conventional devices. Therefore, an improved magnetic disc device has been developed, which has a high memory density enriched by increasing the number of magnetic discs.
(2) Description of the Related Art
A conventional magnetic head of a known magnetic disc device is illustrated in FIGS. 13a and 13b. A magnetic head 5 includes coil lead wires 5a which are drawn upward in the direction opposite to a slider surface 5b. With this structure, the lead wires 5a may sometimes come into contact with a disc surface disposed above the magnetic head or another magnetic head disposed above and opposing this magnetic head 5 which will cause a short circuit or an instability of the head when in operation the head is separated from the disc surface and floating thereon.
Also, the conventional magnetic disc device includes a head actuator having a pivot 6f, as shown in FIG. 14. The pivot 6f has a plurality of head arms 6e which are secured to an outer sleeve 10. The outer sleeve 10 is installed on a stationary shaft 12 through two roller bearings 11 and 11'. The shaft 12 is disposed on a seat 12a for vertical positioning when secured to the base 1 through a screw. The diameter of the seat 12a is approximately the same as that of the outer sleeve 10. Therefore, the space corresponding to the height H of the seat 12a is wasted, thus causing an unnecessary enlarging of the case of the magnetic disc device.
A magnetic device has a record medium on which information data is recorded and a magnetic head for reading the information from that medium. The magnetic head is disposed in such a manner that it faces the recording area of the record medium, to transmit 10 information data between the record medium and a read/write device.
When a magnetic disc is used as the magnetic medium, the head is attached to a head arm which carries the head and positions it at a desired track in the recording area of the magnetic disc. Therefore, in order to achieve an accurate positioning of the head at a high speed, it is necessary to reduce the weight of the head construction, including the head arm, to minimize the inertial force thereof.
A known magnetic head structure is illustrated in FIG. 12. A head 33 is supported at an end of a gimbal 32 which is secured to a head arm 31. Information data is transmitted between the head and a read/write device through a lead wire 34. A springy clip 35 made of plastic is attached to the head arm 31 to hold the lead wire 34 between the head arm 31 and the clip 35 along the head arm side edge.
With the above-mentioned magnetic head structure of the prior art, the head arm 31 becomes heavy, since the clip 35 is used for holding the lead wire 34, thus opposing the requirement for reducing the weight of the head arm structure. Also, the gap between the discs must be wide enough to accommodate the clips 35 therebetween, thus preventing a reduction of the height of the magnetic device.