JPS633027Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides at least one magnetic head 9 to 12 on the surface of a rotating magnetic disk of a magnetic disk storage device for storing and reproducing digital data.
A swinging arm device for moving and positioning a swinging arm, comprising at least one swinging arm,
The arm is pivotable about a pivot axis and has a first end and a second end; includes at least one magnetic head connected to the swinging arm near the first end; a permanent magnetic stator containing child permanent magnets; said magnets being spaced apart from each other with an air gap between them; and a flat control coil made of electrically conductive material, which coil is oscillating. The present invention relates to a swinging arm device which is coupled to an arm and is movable within the air gap of a stator; the swinging arm device is provided with a bearing device which pivotally supports the swinging arm.

Magnetic disk storage devices include one or more rigid magnetic disks, each magnetic disk having the function of storing and reproducing digital data on at least one side, and usually both sides, and for data processing such as a computer. It is used on a large scale as a peripheral device for equipment.

Magnetic disks rotate at high speeds, for example 3600 revolutions per minute. A magnetic head fixed to the end of the carrier arm device moves the magnetic disk surface to a preselected location by the data processing device for storing data on a particular track on the magnetic disk or for reproducing data from said track. They are moved by those above them and carried away. The carrier arm arrangement includes a carrier arm that can move radially linearly or pivot about a pivot axis parallel to the axis of rotation of the magnetic disk. The present invention relates to a carrier arm arrangement of the above type, hereinafter referred to as a swing arm arrangement. The magnetic head must move as quickly as possible over the magnetic disk to select the correct track location and minimize the time required to store or reproduce data. The magnetic disk is made with extremely high flatness, and the magnetic head floats very close to the surface of the magnetic disk on a very thin film of air.

Each magnetic head is often mounted on an elastic magnetic head carrier in order to obtain mobility that allows the magnetic head to float on a film of air and to provide an elastic load that exerts a precisely defined pressure on said head. Fixed. In order to minimize the external dimensions of magnetic disk storage devices, attempts have been made by various manufacturers to place magnetic disks as close to each other as possible. The carrier arm arrangement, especially when inserted between two magnetic disks, must be as flat as possible and must move as close to the magnetic disk surface as possible. It is clear that the carrier arm should never touch the magnetic disk surface. This is because when this contact occurs, the magnetic disk becomes useless. Carrying arm arrangements for magnetic disk storage devices must be made with the necessary accuracy.

A swinging arm device of the type mentioned at the beginning of the text is known from US Pat. No. 4,150,407. This known swing arm device consists of one or more aluminum swing arms in the form of a bifurcated lever, which arms can pivot about a pivot axis located between two ends. A magnetic head unit located near one end of each swinging arm includes a magnetic head and a resilient magnetic head carrier rigidly connected to the carrier arm. A control coil is arranged at the other end of the swing arm. This coil belongs to the actuation means that can be controlled electromagnetically and electrically,
By this means it is possible to make a pivoting movement of the swinging arm around its pivot axis,
This allows the magnetic head to be moved substantially radially over the magnetic disk.

In embodiments that include a plurality of swing arms, the arms are spaced apart above and below each other and are coupled to form a swing arm assembly that is pivotable about a pivot axis. Each swing arm carries an individual flat control coil, which are also coupled to form an assembly of spaced apart control coils. The swing arm assembly is pivotally supported on the frame by a bearing device, the bearing device comprising a ball bearing and a bearing pin, the inner races of the ball bearings being spaced apart from each other in the axial direction by suitable means to support the bearing pin. fixed on top. The inner race of the ball bearing is housed within a bearing housing that is screwed to the deck of the magnetic disk storage device. In this case the compression spring between the outer races eliminates axial bearing play. The control coil moves within a permanent magnetic stator. The stator comprises a stator frame and a plurality of flat axially magnetized stator permanent magnets. The magnets are connected to a stator frame, and an air gap is provided between the magnets for each flat control coil, so that each control coil has an axial permanent magnetic field within the air gap between the stator permanent magnets. can move within. Iron stator end plates located on each side of the stator extend over the intervening control coils and stator magnets, and the outermost stator magnets are mounted on said end plates, thus creating an axial permanent magnetic field. The stator magnetic field is closed through the iron stator end plates. Each control coil consists of a turn of electrically conductive material wound on a plastic coil former, thus forming a single structural unit with the control coil from the synthetic resin. The control coil is connected to the swing arm by clamping and gluing at the end of the swing arm remote from the magnetic head.

A swinging arm device of the type mentioned at the beginning of the text is known from US Pat. No. 4,196,456. This known rocking arm device is very similar to the known rocking arm device described above, but the control coil is not mounted directly on the rocking arm, but is stacked as a separate unit on the bearing bush. . The bearing pin is fixed.

The object of the invention is a swinging arm device of the type mentioned at the beginning of the text, which has small dimensions, a very compact construction and a relatively low pivoting mass.
This results in a swinging arm device with a small diameter, e.g.
It is an object of the present invention to provide a swinging arm device which is particularly suitable for magnetic disk storage storage devices with magnetic disks on the order of cm or less, and which allows the storage storage devices to be used on a large scale.

In the present invention, a flat control coil is disposed in a recess of the swing arm; a bearing device is located near the second end of the swing arm; and a flat control coil is located near the first end of the swing arm. It is characterized by being placed between the second ends. The control coil of each swinging arm is located between the two ends of said arm, and since the pivot axis and magnetic head are located at each end, the swinging arm has a minimum mass.

One embodiment of the invention, of simple and inexpensive construction and satisfactory quality, is such that the swinging arm is made from a single flat piece of sheet material; the thickness of the flat control coil makes up the swinging arm. substantially equal to the thickness of the sheet material; the shape of the recess for the control coil in the swing arm corresponds to the peripheral shape of the control coil, and the control coil is housed with a gap in the recess. the control coil is attached to the wall of said recess by a film of adhesive; the control coil is located in the plane of the swing arm, so that the swing arm to which the control coil is glued is substantially It is characterized by forming a flat unit with a constant thickness. In order to produce a control coil with an optimum winding density in order to minimize the volume and therefore the mass moment of inertia of the control coil, an advantageous embodiment:
The control coil has a central flat coil former wrapped with turns of electrically conductive material; the electrically conductive material consists of an elongated strip, said strip having a width equal to the thickness of said coil and substantially It is characterized by having a thickness smaller than this.

In order to obtain a satisfactory heat transfer from the coil to the swinging arm, an advantageous embodiment provides that the adhesive joining the control coil is mixed with a metal powder, preferably of the same metal as that of which the swinging arm is made. It is characterized by the fact that

The invention will now be described in detail with reference to the illustrated embodiments.

The magnetic disk storage device includes a frame 1, and a swinging arm device 2 is fixed to the frame. Two rigid magnetic disks 3 and 4 are coaxially arranged on a common spindle 5, spaced apart from each other, and rotated about an axis of rotation 6. The swing arm arrangement 2 and the magnetic disks 3, 4 are covered by a plastic cover 7. This cover protects the magnetic disks 3, 4 from dust and other contaminants. For the sake of brevity, explanations and illustrations of parts of the magnetic disk storage device that are outside the scope of the present invention will be omitted, and in this regard, a box-shaped unit 8 that houses the electrical circuits necessary for the operation of the magnetic disk storage device will be omitted.
This is only shown here.

The details of the swing arm device of the present invention will be explained below with reference to FIG. The swinging arm device serves to move and position the four magnetic heads 9-12 over the two rotating rigid magnetic disks 3,4. The magnetic heads are separated from each other by a distance corresponding to the spacing between the magnetic disks 3 and 4 and are arranged on a single swinging arm 14 which is pivotable about a pivot axis 13. These magnetic heads are mounted on a single mounting device 15. The mounting device is formed with the surfaces, recesses, threaded holes, etc. necessary for positioning and mounting the magnetic head on the swing arm. The mounting device 15 is fixed to the swinging arm 14 by gluing. Each magnetic head 9 to 12 is arranged respectively on a resilient magnetic head carrier 9a to 12a, each of which has at its end a fixing part 9b to 12b, each of which is provided with a fixing bushing 9c to 12c, respectively. There is. The mounting device 15 has a through hole 16,
The fixed bushing is housed in this with a slight gap. In order to fix the magnetic head unit (consisting of the magnetic head, the elastic head carrier and the fixing part) on the mounting device 15, a slightly oversized ball is pushed through the associated fixing bush and the gap between this fixing bush and the through hole is eliminated. This magnetic head unit is available on the market.

The center of gravity of the assembly consisting of the mounting device 15 and the magnetic heads 9 to 12 arranged thereon lies substantially in the pivot plane of the swinging arm 14. This also applies to other members of the magnetic head unit. However, these members have substantially less mass than the magnetic head and mounting device.

The mounting device 15 has a plurality of projections 17, 18, 19 for mounting the magnetic heads 9 to 12 at regular intervals, and these projections form a comb-like body. The attachment device has a plurality of members 20, 21, 22 which are removably fixed to each other and each of which includes a comb-like protrusion. Member 20, 2
2 is fixed to the center member 21 with bolts 23 and 24. Member 21 is adhered to swing arm 14 in the manner described above. This bonding is performed before the magnetic heads 10, 11 are connected to the protrusion 18 by means of the fixing bushes 10c, 11c. The magnetic heads 9 and 12 are connected to the center member 2 by bolts 23 and 24.
1, the protrusion 1 of the members 20, 22
Connect to 7,19. In this way, the easily damaged magnetic head unit can be easily mounted on the mounting device 15.

The swing arm has a first end 25 and a second end 26.
The magnetic heads 9-12 are connected to the swing arm near the first end 25. The swinging arm device has a flat stator/permanent magnetic stator 2 with permanent magnets 28, 29.
Contains 7. The stator and magnets are spaced apart from each other, and there is an air gap 3 between them as shown in FIG.
0 is formed. A flat control coil 31 of electrically conductive material is arranged in this air gap and is connected to the swinging arm 14. The swing arm 14 is rotatably supported by a bearing device 32 .
The flat control coil 31 is located in the recess 3 of the swinging arm 14.
Place within 3. The swing arm is die-cut from a sheet of aluminum, and the recess 33 is created during this die-cutting operation. The bearing arrangement 32 is located near the second end 26 of the swing arm, and the control coil 31 is located between the first end 25 and the second end 26 of the swing arm.

The swing arm is made from a single piece of flat sheet material, and the planar control coil 31 has a thickness substantially equal to the thickness of the sheet material from which the swing arm is made. The shape of the recess 33 in the swinging arm corresponds to the shape of the surroundings of the control coil 31, which coil is accommodated in this recess with clearance.

The control coil is glued into the swing arm 14 and attached to the wall of the recess 33 by a film of adhesive. The control coil lies in the plane of the swing arm, so that the swing arm to which it is glued constitutes a flat unit of substantially constant thickness. The control coil turns 34 are made of conductive material and are wound onto a central flat plastic coil former 35. The conductive material is made from an elongated aluminum strip 36 rather than from elongated copper wire, as is customary for control coils.
This strip has a width equal to the coil thickness “d”;
and has a thickness substantially less than said thickness. The adhesive bonding the control coil 31 to the wall of the recess 33 is mixed with aluminum powder to ensure satisfactory heat transfer between the coil and the sheet metal of the swing arm.

The two outermost magnetic heads 9 and 12 of the stack of magnetic heads 9-12 are shielded from spurious magnetic fields by metal shields 37, 38. The shield is a mounting device 1
It is connected to the swing arm 14 via 5. These shields are formed with openings 39, 40 and are connected, together with parts 20, 22 of the mounting device 15, to the central member 21 of the mounting device by bolts 23, 24, respectively. An integrated semiconductor circuit 41 is attached to the lower shield 38, and the magnetic heads 9 to 12 are connected to each other.
Process the signal from. The signal may be amplified before being sent to the signal processing section of the magnetic disk storage device. A semiconductor circuit 41 is mounted on a flexible plastic strip 43 having conductive tracks 42. The strip is secured to the shield 38 at a first end 44. Near the second end 45 the plastic strip is connected via a multi-pole connector 46 to a fixed connector on the frame 1 of the magnetic disk storage device. Between the first end 44 and the second end 45 the plastic strip 43 has a free portion 47 which prevents the swinging arm 14 from moving.

A bearing device 32 that rotatably supports the swinging arm.
consists of a first ball bearing 48 and a second ball bearing 49, which are respectively inner races 50, 51 and outer races 52,
It has 53. The two inner races 50, 51 are fixed axially apart from each other on the bearing pin 54 by round clips 55 and nuts 56. ball bearing 48,
49 are placed on both sides of the swing arm 14. The swing arm has an opening 57 for the bearing pin 54. Rings 58 and 59 arranged on each side of the swing arm are ball bearings 4.
A swing arm is held between inner races 50 and 51 for 8 and 49. The outer races 52, 53 of the ball bearings engage bearing housing means, which consist of first and second bearing housings 60, 61, respectively. The axial clearance between the outer races 52 and 53 of the ball bearing is eliminated in such a way that it is pressed axially by pressure spring means in the form of a cup-shaped spring 62. The spring is located on top of the upper ball bearing 48 near the outer race 52. The ball bearings are a sliding fit within the bearing housings 60, 61, and cup-shaped springs 62 push the ball bearings axially toward each other. Each bearing housing consists of a length of extruded tube;
This tube is the outer race 5 of two ball bearings 48, 49.
2 and 53, and three parallel through holes 64 with smaller cross sections. These through holes 64 are located around the center hole 63. The bearing housings 60 and 61 are fixed with tack pin screws 65 fitted into the through holes 64.

The permanent magnetic stator 26 has two iron stator end plates 6.
6, 67, these end plates are located one on each side of the stator, with a control coil 31 sandwiched between them and a stator magnet 2.
8,29. The magnets are glued onto the stator end plates. The stator magnet is the swing arm 14
is magnetized axially in the direction of the pivot axis 13 of.
The stator magnet 28 has two sections 2 of opposite polarity.
8a and 28b. Magnet 29 also includes two oppositely polarized areas 29a, 29b. On the side facing the control coil 31, the area 28 is connected to the area 29a.
and area 28b has an opposite polarity to area 29b. As a result, the portions of the control coil 31 between the stator permanent magnets are located in a permanent magnetic field of opposite polarity. The axial permanent magnetic field is closed by two iron end plates 66, 67. It is obviously also possible to use a plurality of separate magnets instead of the integral stator magnets 28, 29. As an example, stator magnet 28 may be constructed from two parts, with area 28a belonging to one stator magnet and area 28b belonging to the other stator magnet. The end plates 66, 67 of the permanent magnetic stator 27 extend beyond the bearing pin 54 and across the pivot axis 13 of the swing arm 14. Bearing housings 60 and 61 are secured to stator end plates 66 and 67 by tassel pin screws 65. The stator end plates 66, 67 also constitute frame plates for the bearing arrangement 32. 2 stator end plates 6
In addition to 6, 67, stator 27 includes three spacers 68, 69, 70. 3 bolts 71,7
2, 73 and related nuts 74 to 76
The assembly of stator end plates 76, 77 and three spacers 68-70 is thereby joined to form a rigid unit forming the stator frame of the permanent magnetic stator. Bearing housing 60, 61
is fixed to the stator frame, so that the stator frame also constitutes a frame for the completed swing arm device, and the stator end plate 67 also serves to attach the completed swing arm device to the deck 7 of the magnetic disk storage device.
Serves as a board used for mounting on 7. The means for connecting the swinging arm arrangement 2 to the deck 77 are not shown, but these usually consist of screw means.

The embodiment of the oscillating arm device shown in the figure comprises a tacho-coil 78 which is connected to the oscillating arm 14 for generating an induced voltage which is the magnitude of the swiveling speed of the oscillating arm 14. can move within a permanent magnetic field. To do this, a permanent tacho magnet is used.
magnets) 79 and 78 are arranged outside the stator end plate 67. These magnets are magnetized axially oppositely in the direction of the pivot axis 13. Instead of two magnets, a single flat magnet with areas of opposite polarity can also be used. The stator end plate 67 also serves to close the axial magnetic field created by the two octopus magnets 79, 80 on one side. On the side of the stator end plate 67 the bearing pin 54 has a free end 81 which extends through an opening 82 in said stator end plate and beyond its outer surface. A tacho coil 78, which is flat like the control coil 31, is fixed to the free end 81 of the bearing pin 54 by a nut 83 and is connected to the tacho magnet 79,
can move within the permanent magnetic field created by 80. An iron octopus end plate 84 is arranged parallel to the stator end plate 67 at a certain distance from the end plate.
The octopus coil 78 moves parallel to the flat octopus magnets 79, 80 to maintain an air gap between the stator end plate 67 and the octopus end plate 84, so that the axial permanent magnetic field of the octopus magnet is directed on one side by the stator end. It is closed by a plate and on the other side by an octopus end plate. Stator end plate 84 is secured to the underside of deck 77 by four tassel pin screws 85, but could alternatively be secured to stator end plate 67 by separate spacer means.
The tacho magnets 79 and 80 and the tacho coil 78 are arranged in a recess 89 of the deck 77.

The two stator end plates 66, 67 consist of substantially identical plates cut from flat magnetizable sheet material. It is therefore advantageous that these plates can be produced inexpensively using simple means and that only one type of stator end plate needs to be produced. The requirements for manufacturing accuracy are not critical, so the end plate does not need to undergo any machining after die cutting. Stator magnet 28,2
9 extends substantially transverse to the direction of rotation of control coil 31 and also extends slightly beyond the edges of stator end plates 66, 67, as also shown in FIG.

A stop 90 is provided on each side 91, 92 of the wall of the recess 95 of the swing arm 14.
Collaborate with 3,94. Stop sides 91, 92 limit pivoting movement of the swing arm between the first and second positions. Figures 4 and 5 show the swing arm 14 in a first or inner position and a second or outer position, respectively. The stop 90 is made of rubber and has an operating position shown in FIG.
It is possible to move between the storage positions shown in FIG.
The stop, made entirely of elastic rubber, consists of a rotatable stop cam which fits somewhat tightly onto the spacer 68. To do this, the stop has an opening with a diameter slightly smaller than the outer diameter of the spacer 68. This aperture is eccentric to allow eccentric rotation of the stop cam between an actuated position and a storage position. In the storage position, the stop cam is rotated 90°.

In this position, the side surfaces 93, 94 of the wall of the recess 95 cooperate with the opposite sides 97, 98 of the stop cam. The side surfaces are located closer to each other than the distance between the side surfaces 91 and 92. As a result, for storage purposes, the swing arm 14 can be pivoted until the magnetic heads 9 to 12 are located next to the surfaces of the magnetic disks 3 and 4. This location also allows the magnetic head to be attached to the magnetic disk drive without causing damage during assembly of the magnetic disk drive.

Many other embodiments are within the scope of the invention. The swinging arm need not be made of flat sheet material, but can also be made, for example, by die-casting or have a molded shape. The control coil may be arranged on a support and, by locally connecting this support to the swing arm, it can be placed in a larger recess than the control coil. The control coil can be arranged further aside with respect to the connection line between the magnetic head and the pivot axis.

[Brief explanation of the drawing]

Figure 1 is a plan view of a magnetic disk storage device;
The figure is a side view of the magnetic disk storage device shown in FIG. 1; FIG. 3 is an exploded view of the swinging arm device used in the magnetic disk device shown in FIGS. 1 and 2; FIGS. 4 to 6 are the swinging arm device FIG. 6 is a diagram showing the swinging arms of the embodiment in different positions. 1... Frame, 2... Swinging arm device, 3,
4... Magnetic disk, 6... Rotating shaft, 9-12...
... Magnetic head, 14... Swinging arm, 15... Mounting device, 27... Permanent magnetic stator, 28, 29...
...Stator/permanent magnet, 30...Air gap, 31...
... Control coil, 32 ... Bearing device, 33 ... Recess, 35 ... Coil forming tool, 37, 38 ... Myu metal shield, 41 ... Integrated semiconductor circuit, 42
... Conductive track, 43 ... Flexible plastic band, 48 ... First ball bearing, 49 ... Second ball bearing, 50, 51 ... Inner race, 52, 53 ... Outer race, 64 ... Through hole, 66, 67... Stator end plate, 68-70... Spacer, 77... Deck, 78... Octopus coil, 79, 80... Permanent tacho magnet, 90... Stop.

Claims (1)

[Claims for Utility Model Registration] 1. Rotating magnetic disks 3 and 4 of a magnetic disk storage device for storing and reproducing digital data.
at least one magnetic head 9-1 on the surface of
A swing arm device 2 for moving and positioning a swing arm 2 comprising at least one swing arm 14 which is pivotable about a pivot axis 13 and which has a first end 25 and a first end 25 . at least one magnetic head 9-12 connected to the swinging arm 14 near the first end 25; a flat stator permanent magnet 28;
29, said magnets being spaced apart from each other with an air gap 30 between them; and a flat control coil 31 of electrically conductive material, which coil is oscillating. In a rocking arm arrangement such as a rocker arm 14 which is connected to the rocker arm 14 and movable within the air gap 30 of the stator; control coil 3
1 is placed in the recess 33 of the swing arm;
The bearing arrangement 32 is located near the second end 26 of the swinging arm 14; the flat control coil 31 is characterized in that it is arranged between the first end 25 and the second end 26 of the swinging arm 14. Swinging arm device. 2 Utility Model Registration In the rocking arm device according to claim 1, the rocking arm 14 is made from a single flat piece of sheet material; the thickness d of the flat control coil 31 makes the rocking arm 14 substantially equal to the thickness of the sheet material made; the shape of said recess 33 for the control coil in the swinging arm corresponds to the peripheral shape of the control coil 31, and the control coil has a certain gap in said recess. the control coil is attached to the wall of said recess by a film of adhesive; the control coil is located in the plane of the swing arm, so that the control coil is attached to the wall of the recess; A rocking arm device, characterized in that the arm constitutes a flat unit of substantially constant thickness. 3. In the rocking arm device according to claim 2, the control coil has a central flat coil former 35 around which a turn 34 of conductive material is wound; the conductive material is elongated. comprising a strip 36, said strip having a width equal to the thickness d of said coil and a thickness substantially less than this;
A swinging arm device featuring: 4 In the swinging arm device according to claim 2 of the utility model registration, the swinging arm 14 is made of metal, and the adhesive bonding the control coil 33 is metal powder, preferably the metal that makes the swinging arm. A rocking arm characterized by being mixed with the same metal powder.