JPS61221566A - Rotary actuator used within disc drive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to sensing head actuators for use in magnetic disk drives, and more particularly to removable rotary actuators.

A disk with a magnetic coating on its surface provides a memory for bits of data that can be accessed quickly and randomly for data retrieval or storage. Typically, the heads are mounted on support arms and each head moves rapidly across the disk surface while the disk is rotated to detect or store data in concentric data tracks on the disk surface. It has a small detection coil. These heads rest on a thin layer of air created by the rotating disk, with the heads approaching but away from the surface of the disk.

The detection head actuator is capable of linearly moving the head arm assembly across the disk surface and rotatably moving the head arm assembly across the disk surface. A beam near motor is disclosed in U.S. Pat. No. 4,305,105.

Rotary actuators have historically had one of two types of helad arm attachments. The pivot point is often fitted with a single rigid arm with a shaped beam cross-section, which extends most of the distance to the recording head. One or more brackets supporting the head are then attached to the ends of the arms. Although this facilitates head replacement, the inertia of the actuator is relatively large. An alternative to this method is to vertically stack individual head arms to form an actuator assembly, which reduces the inertia of the actuator but requires the entire actuator to be removed to remove one head. Must be disassembled.

It is an object of the present invention to provide a rotary actuator and head assembly that has low inertia and allows the head assembly to be easily assembled and disassembled for repair.

Briefly stated, the rotary actuator according to the invention comprises a support structure which not only houses the magnets of the motor (but also a pivot block for moving the detection head and arm, and bearings and bearings for the pivot block). Includes support shaft.

The pivot block has a plurality of dovetail slots on one side for receiving the head arm and a coil assembly on the other side for movement between the magnets in the magnet structure. .

The head arms are removable from the dovetail slots for testing and repair, and the detection heads mounted on each arm are interconnected to connectors that mate with connectors on the drive electronics block. Thus, the arm can be easily connected to and disconnected from the pivot block and disk drive both mechanically and electronically.

The invention, objects and features thereof will become apparent from the following detailed description and claims, taken in conjunction with the accompanying drawings.

Referring now to the accompanying drawings, FIG. 1 depicts a rotary actuator (generally designated 10) according to one embodiment of the present invention for accessing and storing data on a plurality of disks 12 mounted on a spindle 14. ) is a perspective view of. The rotary actuator 10 includes a first support structure 16 containing a magnet 18 and a second support structure 20 supporting a magnet 22, which support structures are welded or brazed together to form a unitary structure. It can be formed from two parts. In contrast to the above methods, the structure can be investment cast as a single piece. Preferably, grooves are formed in the support structure to receive magnets which are fixed therein by suitable means such as epoxy.

The support structure supports a pivot block assembly, which is best shown in the partially sectional plan view of FIG. 2 and the exploded perspective view of FIG. 3. This pivot block 30 fits onto the bearing support shaft 32 and is fastened by bolts 33 which deform the block slightly to allow a tight fit on the shaft.

A shaft 32 is mounted to the bearing within the magnet structure, and the head arm 34 preferably fits within a dovetail slot 36 on one side of the pivot block. These arms are firmly fastened by fixing screws 37.

A coil holder 38 is provided on the other side of the pivot block 30.
There is a holder 38 to which a coil 40 is attached by suitable means such as epoxy. Coil holder 3
8 is preferably a separate part which is fastened to the pivot block by bolts 42. Coil 40 is flat and suitable for low profile drives.

A detection head assembly 44 including a bending body 45 and a head 46 is attached to one end of the arm 34 . Preferably, two detection head assemblies 44 are mounted on either side of each arm 340, with heads 46 in a common plane and aligned in a staggered manner. This allows the arms within the pivot block 30 to be closely spaced. Electrical leads 48 to head 46 connect to ribbon cable 50, which is then plugged into the electronics of a disk drive (not shown).

In operation, coil 40 is located between magnets 18 and 22.
When energized, the pivot block and head arm assembly rotate to move the detection head across the surface of the disk. Remove the fixing screw 37,
The head arm 37 can be easily removed from the dovetail slot by disconnecting the electrical connector. The detection head can therefore be easily tested and repaired.

A rotary actuator with a removable head arm in accordance with the present invention provides a low profile disk drive and a low inertia actuator that is easily assembled and repaired. The description is intended to be illustrative of the invention and is not to be considered limiting, and will be understood by those skilled in the art without departing from the true spirit and scope of the invention as set forth in the claims. Various modifications and uses may be envisaged.

[Brief explanation of the drawing]

1 is a perspective view of a rotary motor and actuator assembly according to the present invention; FIG. 2 is a top plan view, partially in section, showing the pivot block within the magnet structure; and FIG.
The figures are perspective views showing the assembly and disassembly of the head arm within the dovetail slot in one side of the pivot block according to the invention. 10...Rotary actuator 16...
...First support structure 18 ... Magnet 20 ... Second support structure 30 ... Pivoting block 34 ... Head arm 36 ... ...Dovetail slot 38...Coil holder

Claims (5)

[Claims] (1) a support structure for supporting a plurality of magnets in a spaced-apart manner, a shaft means supported by the structure and rotatable within the support structure, and rotating together with the shaft means; a pivot block assembly mounted on said shaft means to provide a coil for said pivot block assembly, said pivot block assembly having a coil extending from one side of said pivot block assembly with said coil positioned between said plurality of magnets. and a coil retaining means, and a dovetail slot on the other side of the pivot block assembly for slidably receiving a plurality of head support arms, and further slidably engaged in the dovetail slot. A rotary actuator for use in a disk drive that includes a plurality of head support arms configured to fit together. 2. The rotary actuator of claim 1 further comprising screw means for fastening each of said support arms within said dovetail slot. (3) Each of the head support arms has a first and a second head support arm.
A rotary actuator as claimed in claim 1 including a detection head assembly. (4) The rotary actuator according to claim 3, wherein the first and second detection head assemblies are attached to the other side of the support arm. 5. The rotary actuator of claim 4, wherein each sensing head assembly includes a sensing head, and the heads on the first and second sensing head assemblies are generally coplanar and offset.