JPS6346906B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for positioning a transducer head with respect to a magnetic disk having concentric tracks, the device comprising a head carrying arm movable radially with respect to the disk and a transducer head associated with each track of the disk. and a positioning member defining a series of positions of the arm.

In known devices of this kind, the forward movement of the head carrying arm is provided by a step motor connected to this arm via a rack and pinion, and the positioning member has a series of V-shaped notches attached to the head carrying arm. Consists of a fixed bar. When the step motor is at rest, two positioning wedges engage notches in the bar to fine tune the position of the head on a selected track. A pair of electromagnets associated with these two wedges is energized when the step motor causes movement of the arm, thereby disengaging both wedges from their respective notches in the bar. Such known devices, which utilize a step motor, an associated drive circuit and two electromagnets for selecting the positioning wedge, have the disadvantage of being complex and expensive.

The object of the invention is to provide a device for positioning a transducer head with respect to a magnetic disc with concentric tracks, which is simple in construction, reliable in operation and inexpensive.

To achieve this objective, the apparatus of the invention includes a blocking element that engages a positioning member to position the head on a selected track, and a block element that releases the blocking element from the positioning member and moves the head from one concentric track to another. and a periodically rotatable cam for advancing the head a predetermined amount along the radial direction of the disk into the track and then reengaging the block element with the positioning member.

1, 2 and 3, the device according to the invention, shown as a first embodiment, comprises a frame 1 equipped with a rotating spindle 11 for rotating a flexible magnetic disk 12.
has 0. Disc 12 and spindle 11 are of the known type as disclosed in US Pat. No. 4,024,581.

The transducing head 14 is mounted on a head carrying arm 15 which is movable radially with respect to the disc 12 to position the head 14 over a concentric recording track 16 of the disc. Arm 15 is located substantially horizontally and is hinged to pivot 18 of frame 10.

A rectangular window 22 provided on the side 20 of the frame 10
accommodates the terminal end 23 of the arm 15 with sufficient clearance. A block pivot 24 of circular cross section is mounted on the terminal end 23 of arm 15. The helical spring 19 located between the frame 10 and the arm 15 presses the arm 15 upward,
The block pivot 24 is normally retained within one of the V-shaped notches 28 of the locating bar 25 which is secured to the side 20 by two screws 26.

The number of notches 28 corresponds to the number of concentric tracks 1 on disk 12.
6 and the distance between the two notches is selected such that when the pivot 24 moves from one notch 28 to the next, the translation head moves from one track 16 to the adjacent track 16. Ru.

A reversible motor 31 having a shaft 32 is connected to the side 2
0, the shaft 32 is in spline engagement with a first eccentric cam 33, and the cam is engaged with a circular hole 34 in the bar 35. The toothed belt 36 is suspended between a guide pulley splined to the shaft 32 and a guide pulley 38 splined to a hub 39 rotatable on the side 20. A second cam 40 similar to the cam 33 is splined to the hub 39;
rotates synchronously with cam 33 and engages fork lever 42 (FIG. 2) of bar 35. Therefore, when the shaft 32 rotates, the bar 35 moves while maintaining a horizontal position while taking a position corresponding to the periphery of the cam.

The lower edge 43 of the bar has a plurality of semicircular notches 44.
has. The distance between these notches 44 is equal to the distance between two adjacent V-shaped notches 28.

A synchronizing disk 45 having a window 46 is splined to the shaft 32 and is located between a light emitter 47 and a phototransistor 48 which senses the passage of the window 46 on each revolution of the shaft 32. .

The operation of the device described above is as follows.

In the rest position, the arm 15 has moved towards the motor 31 and the head 14 has moved towards the disk 12 (first
It is located on the peripheral track 16 of FIG. The motor 31 is at rest, the bar 35 is raised and the notch 44 is pulled away from the fixed notch 28.

To move the head 14 from the peripheral track 16 to the adjacent inner track 16,
The motor 31 is rotated one rotation clockwise (FIG. 2).
Then, since the cams 33 and 40 move synchronously, the bar 35 performs a unit movement. In particular, pivot 24
The center 44' of notch 44 on the left side traces a circle as shown in broken lines in FIG. 3, and during this movement notch 44 engages pivot 24 after one-quarter turn. Then, after 1/2 turn, when the center of notch 44 is at position 44'', the notch causes the pivot to ride over the teeth between the two V-shaped notches 28, and before the bar movement is complete, Notsuchi 44 is
The pivot is moved into the next notch 28 adjacent to the V-shaped notch 28 that previously housed the pivot in the bar.

As a result, from what has already been said regarding the distance between the notches 28, the conversion head is perfectly positioned on the track 16 adjacent to the peripheral track. Accidental positioning errors due to incomplete rotation of the drive shaft are corrected by the positioner 25 via the V-shaped notch 28. Furthermore, one notch 2
8 to the next adjacent notch 28 is less than the movement of the terminal end 23 of the arm 15, an accidental structural error in the positioner 25 will cause the head 14 to move relative to the track of the disc 12.
This has almost no effect on positioning correction. This is a common feature in the other solutions mentioned above.

When rotation of the drive shaft 32 is complete and the bar has completed its travel, the window 46 in the synchronizing disk 45 is sensed by a phototransistor 48, causing capture of the disk in a known manner.

Similarly, in order to move the head 14 radially with respect to the disc 12 from an initial or circumferential track to a track 16 further away, a motor 31 is used.
performs a number of rotations equal to the number of tracks between the current position of the head and the selected new track 16.

Since the V-shaped notch 28 and the semicircular notch 44 are symmetrical, the counterclockwise rotation of the motor 31 is caused by the rotation of the disc 1.
This causes a stepwise movement of the conversion head 14 from the center of the head 2 towards the periphery.

According to a second embodiment shown in FIGS. 4 and 5, the device according to the invention has a carriage 50 fitted with a conversion head 14, which slides on two parallel guides 51, 52. Carriage 50
A spring 53 tensioned between the pivot 54 and the stationary side 55 normally holds the carriage 50 away from the spindle 11.

A freely rotating wheel 58 mounted between two pins 56, 57 of the carriage 50 carries a flexible belt 59 made of steel, for example. One end of the belt 59 is fixed to the bent portion 60 of the frame 10, and the other end is fixed to the frame 10 with a screw 62.
It is fixed to a free rotation wheel 63 attached to the. The wheel 63 carries at the top a splined disc 64 having a radial slot 68.
A disk 65 with a substantially square plate 66 is arranged coaxially and freely with respect to the wheel 63.

A connecting rod 70 having a rectangular window 71 whose short side is substantially equal to the length of one side of the square plate 66 is mounted between the upper disc 65 and the lower disc 67.
The terminal end 72 of the connecting rod 71 is connected to a pivot 73 mounted eccentrically on a cylinder 74 splined to a drive shaft 75 of a reversible electric motor 76 secured to the frame 10. Synchronous disk 7
7 is also splined to the shaft 75 and has a notch 78, and is located between the light emitter 79 and a phototransistor 80 which senses the passage of the notch 78 on each revolution of the shaft 75.

A positioner 82 consisting of a lever 83 pivoted on a fixed pivot 84 has a vertical pivot 85 normally inserted into one of the radial notches 68 of the disc 67 under the action of a spring 86.

The connecting rod 70 has a front surface 87 cooperating with a lever 83 of a positioner 82 and an upper vertical pivot 81 that periodically engages a radial notch 68 in the disk 67.
and has.

The operation of the device according to this second embodiment of the invention is as follows.

In the rest position, the carriage 50
The head 14 is at rest with the head 14 positioned above one of the tracks 16. Motor 76 is stopped and pivot 81 of connecting rod 70 is pulled away from notch 68 in disk 67.

As before, to move head 14 from one track 16 to the next adjacent track, motor 76 is rotated one revolution. In particular, the motor 76 is caused to rotate clockwise to move the head 14 outwardly toward the outer track, and counterclockwise to move the head inwardly toward the inner track. . During rotation of motor 76, pivot 73 rotates and moves connecting rod 73, and in particular pivot 81 traces the trajectory shown in dotted lines in FIG.

During movement, the front face of the connecting rod 70 pushes the positioner 82 away from the disc 67 and places the pivot 81 into the radial notch 68. pivot 81
Rotation of disk 67 by causes a corresponding rotation of wheel 63, which causes movement of carriage 50 via belt 59.

Before the motor 74 completes one rotation, the connecting rod 7
0 leaves positioner 82, which re-engages disk 67 under the action of spring 86.

A third embodiment of the invention, shown in FIGS. 6, 7, 8 and 9, has a horizontal arm 90 on which a transducer head 14 is mounted. The arm 90 is a frame 92
It is pivotally connected to a pivot 91 fixed to. Pivot 91 allows free rocking of arm 90 in horizontal and vertical planes. The arm 90 has a pointed head 93 on its lower surface, which is connected to a screw 9 pivoted eccentrically to a shaft 96 rotating on the frame 92.
It is normally engaged with the threaded portion 94 of No. 5. A gear 97 meshing with a pinion 98 of a reversible motor 99 is in spline engagement with a shaft 96. A peg 100 provided at the end of the arm 90 is a positioning rack 10.
normally engaged with one of the two notches 101 of 2.

The operation of the device according to this third embodiment of the invention is as follows.

In the rest position, arm 90 is stationary and peg 100 engages one of notches 101. To swing arm 90 about pivot 91, motor 95 turns screw 95 one turn. As screw 95 rotates, due to the eccentricity of this screw with respect to shaft 96, arm 90 is pushed upwards and moved horizontally to the left to assume a new position. Thus, the head 14 moves one unit of movement toward the adjacent track 16 of the disk 12.

From the following description, it will be seen that in all three embodiments described above, the device according to the invention includes a support 15 for the head 14 which moves radially with respect to the disc 12;
50, 90; positioning members 25, 67, 102 defining a series of positions for the arm associated with track 16 of disk 12; selected track 1;
block element 2 engaging positioning members 25, 67, 102 for positioning head 14 on 6;
4, 85, 100; positioning member 25, 67,
102, and move the head a predetermined amount along the radial direction of the disc 12 from one concentric track 16 to another;
5, 100 to re-engage the positioning member 25, 67, 102.
It is clear that it consists of 3, 73, 95 and;

[Brief explanation of the drawing]

FIG. 1 is a partially sectional plan view of an apparatus according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. Figure 3 is an enlarged view of a portion of Figure 2. FIG. 4 is a partially sectional front view of an apparatus according to a second embodiment of the present invention. FIG. 5 is a partially sectional plan view of the apparatus of FIG. 4; FIG. 6 is a partially sectional side view of an apparatus according to a third embodiment of the present invention. FIG. 7 is a plan view of the apparatus of FIG. 6. FIG. 8 is a partially sectional front view of the apparatus of FIG. 6; Figure 9 is the 6th
It is an enlarged view of a part of the figure. 10: Frame, 12: Magnetic disc, 14: Conversion head, 16: Concentric track, 15: Arm, 2
5: Positioning lever, 24: Pivot, 28: Notch, 32: Shaft, 33: Cam, 35: Bar, 50: Carriage, 67: Disc, 73: Pivot, 85: Pivot, 90: Arm, 95: Screw, 100: Peg, 102: Rack.

Claims (1)

Claims: 1. A device for positioning a transducer head with respect to concentric tracks of a magnetic disk, comprising: a support for said transducer head movable in a radial direction relative to the magnetic disk; said support relative to the concentric tracks; a locating member defining a plurality of positions of the body; a blocking element engageable with the locating member to position the transducing head on a selected one of the concentric tracks; and releasing the blocking element from the locating member. and then a periodically rotating eccentric for moving the transducing head a predetermined amount along the radial direction of the magnetic disk from one concentric track to another and then re-engaging the blocking element to the positioning member. The device comprising: an element; 2. The device according to claim 1, wherein the support for the conversion head comprises an arm pivoted on a fixed pivot, the positioning member comprises a plurality of V-shaped notches, and the support for the conversion head comprises a plurality of V-shaped notches; A blocking element is mounted at the end of the arm opposite the pivot, and the transducer head is located between the pivot and the blocking element. 3. The device according to claim 1, wherein the support for the conversion head comprises a radially movable carriage with respect to the disc, and the positioning member comprises a series of equally spaced radial notches. 2. A device comprising a disk having a diameter of 1.5 mm, which disk is provided with a cylinder having a diameter smaller than the diameter of the disk, and in which a coupling element is located between the periphery of the cylinder and the carriage. 4. The device according to claim 1, wherein the eccentric element is driven by a reversible electric motor, and a connecting rod is provided which engages the eccentric element, and the connecting rod is adapted to be driven by a reversible electric motor. Said device is adapted to cause a unit movement of said converting head from one of said concentric tracks to another of said concentric tracks with each revolution.