JPS6280882A - Impact force relaxing device to cam - Google Patents

Abstract

PURPOSE:To relax impact force to a cam at the operation of the impact force by adopting the constitution that an arm and a head carriage fitted with a cam follower are not fixed and energized by a relaxing spring for the impact force. CONSTITUTION:When a stepping motor 59 is driven to drive a cam 53 in a reduced speed, a cam follower 45 and an arm 47 follow the shape of the cam face and a carriage 35 adhered close by them and a torsion coil spring 51 is incorporated and moved along a guide shaft 39. When the impact force is exerted to the carriage 35, the carriage 35 is moved against the torsion coil spring 51 and the arm 47 is driven around a pin 49 and the impact force delivered from the carriage 35 to the cam 53 via the arm 47 and the cam follower 45 is comparatively small. Thus, no recess is formed to the cam 53.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is directed to a method for alleviating the effect of impact force on a cam in a magnetic head feed drive device of a rotating magnetic seven-point device in an electronic still camera system, etc. Regarding devices that can.

<Prior Art> An electronic still camera system that combines an imaging device using a solid-state WL image element or an image pickup tube and a rotating magnetic sheet device as a recording and reproducing device using a magnetic sheet as a recording medium is capable of capturing a subject electronically. The image information is recorded on a rotating magnetic sheet, and the image information recorded on the magnetic sheet is reproduced by a television, printer, etc. The magnetic sheet used in the rotating magnetic device of such an electronic still camera system is rotatably housed in a casing and is generally used in the form of a magnetic sheet pack called a video floppy.

This magnetic sheet has a diameter of approximately 50UL and approximately 100μ
High-density recording is performed on about 52 tracks in the radial direction at intervals of m, and for this reason, in a rotating magnetic sheet device, it is necessary to position the magnetic head with extremely high precision in the radial direction of the magnetic sheet. be.

Several types of feed drive devices have been considered for positioning the magnetic head in the radial direction of the magnetic sheet, and among them, one uses a cam. This is for high-precision cams whose cam lift changes depending on the rotation angle position.
The magnetic head is positioned via the cam follower by bringing the cam follower installed on the caliper horn equipped with the magnetic head into contact with the cam and rotating the cam with a stepping motor. The present invention is suitable for use in a rotating magnetic sheet device of an electronic still camera system because it can be used in a rotating magnetic sheet device.

<Problems to be Solved by the Invention> As mentioned above, in a magnetic head feeding and driving device using a cam, it is necessary to move the magnetic head at intervals of about 100 μm with respect to the magnetic sheet, which is very difficult. A breeding stock cam is required. In particular, when the diameter of the cam is made smaller than the magnetic sheet in order to downsize the rotating magnetic sheet device, high accuracy on the order of microns is required. Several methods have been proposed for manufacturing cams with high precision, but there is a problem in that the precision of the cams decreases during use.

That is, since electronic still cameras are portable, they are easily dropped, subjected to vibrations, and shocks. In this case, the head carriage is displaced in the direction of movement along the guide shaft, and an impact force is applied to the cam via the cam follower. This impact force forms a recess in the cam, and this recess causes deterioration in the positioning accuracy of the magnetic head during recording and reproduction.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide a magnetic head feed drive device that can reduce the impact force on the cam.

Means for Solving the Problems] To achieve the above object, the present invention has a structure in which a head carriage to which a magnetic head is attached is brought into contact with a cam via a cam follower attached to the head carriage. In the feed drive device capable of moving the head carriage by rotationally driving the cam, the cam follower applies a force equal to or greater than a predetermined force to the head carriage in the direction of the moving force of the head gear ridge. The cam follower is attached to the head carriage via an elastic member so that the cam follower and the head carriage are movable relative to each other when wet.

Function> Under normal conditions, the arm is biased by the impact force-reducing spring and remains in close contact with the head carriage, and is integrated with the head carriage to follow the rotation of the cam.
Will have to move. On the other hand, [when four forces act,
The head gear ridge and cam follower move relative to each other against the spring force of the shock force mitigation spring, and only the head carriage moves, so the force acting on the cam via the cam follower is compared by the mass of the cam follower, etc. This is the sum of the small impact force and the acting force of the spring, and the large impact force due to the mass of the head carriage no longer acts.

<Embodiment> An embodiment in which the present invention is applied to a magnetic head feeding drive device of a rotating magnetic sheet device in an electronic still camera system will be described below.

FIG. 3 is a schematic perspective view of the electronic camera body and the magnetic seat puncture according to this embodiment. As shown in FIG. 3, the electronic camera body 1 has an imaging lens system 5 connected to an imaging device 3. As shown in FIG.

The image information obtained there is written on the magnetic sheet 13 in the magnetic sheet pack 11 that is loaded into the rotating magnetic sheet device 7 from the puncture insertion slot 9, and is stored as A. In addition, 15 is a finder, 17 is a viewfinder optical system, 19 is a strobe, 21
23 is a group of operation buttons, and 23 is a battery.

FIG. 4 is a perspective view of the rotating magnetic sheet device 7 shown together with the magnetic sheet pack 11, and FIG. 5 is an exploded perspective view of the main parts thereof. , as shown in FIGS. 4 and 5, the chassis 25
A spindle motor 27 for rotationally driving the magnetic sheet 13 is fixedly installed substantially at the center of the shaft. A chucking magnet 31 for attaching the center core 29 of the magnetic sheet 13 to the rotating shaft of the spindle motor 27 is provided, and the center core 29 is pressed against the chucking magnet 31 by a center core pushing member 111, which will be described later. The air outlet 13 is fixed to the rotating shaft of a spindle motor 27.

Moreover, the spindle motor 27 [
An IC head carriage, that is, a carriage 35 on which a magnetic head 33 is mounted, is supported so as to be slidable in the radial direction of a magnetic cartridge 130 attached to a spindle motor 27, and is moved toward the center of the spindle motor 27 by a tension spring 37. energized. That is, as shown in FIGS. 1 and 2, a magnetic head 33 is mounted on the carriage 35 via a head base 36, and a guide shaft 39 is mounted on one end of the carriage 35, on the right side in FIG. On the other hand, this guide shaft 39 is slidably penetrated through the shear 725 via an oilless metal bearing 41. A spring hook 38 is protruded from each of the carriage 35 and the chassis 25, and a tension spring 37 is stretched between these springs 77238 along the guide shaft 39.
is biased to the left in FIG. On the other hand, Nakayarikuji 35
A shaft 40 is provided protruding from the other end, and large and small idle rollers 42 and 44 are rotatably fitted onto the shaft 40 with an E ring 46 in between, thereby forming a rotation stopper. . This detent fits into a jid groove 43 formed in the chassis 25, and serves as a detent for the carriage 35 and guides the carriage 35 along the kffid shaft 39. That is, the guide groove portion 43 is arranged parallel to the guide shaft 39, and as shown in FIG. 2, the large guide roller 42 rolls into contact with the guide groove portion 43, but an idle grate 48 is provided on the upper side, and a thin plate is provided below the guide groove portion 48 for pushing up the small guide roller 44. spring 50
A stopper plate 52 is provided to support this. Therefore, when the carriage 35 moves along the guide shaft 39, it is pushed up by the four leaf springs 50, and the large guide roller 42 and the small guide roller 44 roll into contact with the guy P plate 48 and the thin leaf spring 50, respectively, and rotate in the opposite direction. becomes. Further, an arm 47 is attached to a pin 49 on the carriage 35.
The arm 47 is rotatably supported around the pin 49 in a direction along the guide shaft 39, and a torsion coil spring 51 is attached around the pin 49. It is urged by the carriage 35 and is in close contact with it. A cylindrical cam follower 45 is attached to the arm 47 through a hinge 54 at the tip thereof, and this cam follower 45 is attached to the chassis 25 on the side of the carriage 35.
The spring force of the tension spring 37 urges the cam surface of the cam 53 which is pivotally supported from the cam 53 . A cam gear 55 is coaxially fixed to the cam 53, and as shown in FIG. A pinion 61 fixed to the rotating shaft of the motor 59 is engaged. Therefore, when the stenbing motor 59 is driven to rotate and the cam 53 is rotated at a reduced speed, the cam follower 45 and the arm 47 follow the shape of the cam surface, and the carriage 35 is in close contact with these by the torsion coil spring 51.
will move together along the guide shaft 39. In addition, a stone 9 pin 56 is attached to the carriage 35, and a head position adjustment screw 58 that comes into contact with this stopper pin 56 is provided passing through the arm 47, and the protrusion amount is adjusted by rotating this screw 58. By changing the position, the position of the magnetic head 33 can be finely adjusted. Furthermore, the first
In the figure, 60 is an arm 47 for passing the guide shaft 39.
This is a hole drilled in the hole.

Furthermore, in the rotating magnetic sheet device 7 in this embodiment,
As shown in FIGS. 4 and 5, the spindle motor 27
between the spindle motor 59 and the shear 725 on the opposite side.
A loading motor 65 is fixedly attached to the drive shaft 25 , and the loading motor 65 rotates a control shaft 67 supported by the steering wheel 25 via a reduction gear unit 69 . Further, first and second encoders 70.71 are provided which rotate in conjunction with the control shaft 67, and photosensors 73.75 are provided corresponding to the encoders 70.71, respectively. 670 rotation position can be detected.

Left and right side plates 77.7 are provided on the left and right side walls of the chassis 25, respectively.
9 is fixed. As shown in FIG. 7, which is a perspective view of the left and right side plates 77 and 79, the left side plate 77 has a left holder 8, which will be described later.
1 in the vertical direction (parallel to the rotational axis of the spindle motor 27). (insertion/extraction direction) support groove 77b
is drilled therein, and a guide bin 77c for supporting a left control plate 91, which will be described later, is implanted on its outer surface. On the other hand, an L-shaped holder guide 479a for guiding a right holder 83 (described later) in the vertical and front-back directions is bored in the right side plate 79, and a guide pin 79b for supporting a right control plate 93 (described later) is implanted on the outer surface. It is set up.

Left and right holders 81 and 83 are attached to the insides of the left and right side plates 77 and 79, respectively.

As shown in FIG. 8, which is a perspective view of the left and right holders 81.83, the left and right holders 81.83 have magnetic sheets 79 and 11.
The left and right side ends of the left and right side edges fit into each other, and the guide shaft 81a implanted on the outer surface of the left holder 81 is inserted into the holder guide groove 77a of the left side plate 77.
By slidably fitting the left holder 81 into the left side plate 77
It is supported so that it can move up and down.

On the other hand, the right holder 83 has guide grooves 83a implanted on its outer surface that are connected to the guide grooves 79 of the right side plate 79.
aK By slidingly fitting the groove 7 into the right side plate 79.
It is supported so that it can move up and down and back and forth along 9a.

Further, the left and right holders 81 and 83 each have a spring-like pack holding portion 81b that presses and holds the magnetic sheet pack 11 when it is inserted.

83b is formed, and the right holder 83 is further provided with a pack detection switch 85 that detects when the magnetic seal 11 is inserted into the right holder 83, and a pack detection switch 85 that detects when the magnetic seal 11 is inserted, and a pack detection switch 85 that controls the opening and closing of the window 87 of the magnetic seal 11. An opening/closing mechanism (not shown) and a gloss extrusion mechanism 89 are provided.

Left and right control plates 91 are provided on the outside of the left and right side plates 77 and 79, respectively.
．． 93 is installed. As shown in FIG. 9, which is a perspective view of the left and right control plates 91 and 93, the left control plate 91 is provided with a guide groove 91a into which the guide pin 77c of the left side plate 77 is slidably inserted. The guide pin 77c
By fitting in, the left control plate 91 is supported by the left side plate 77 so as to be slidable in the front-rear direction. Further, the left control plate 91 has a rack 91b formed at a part of its lower end, and the rack 91b meshes with a pinion 95 fixed to the control shaft 67. The left control plate 91 is adapted to be driven in the front-rear direction. Further, the left control plate 91 is formed with an inclined guide groove 91c that is continuous with one guide groove 91a, and the guide shirt 81a of the left holder 81 is formed with an inclined guide groove 91c.
one of them passes through the holder guide groove 77a of the left side plate 77 and is fitted into the inclined guide groove 91c via the roller 81c. Therefore, by the back and forth movement of the left control plate 91, the left holder 81 moves into the holder guide groove 77a. Move up and down along. Further, the left control plate 91 has an inclined part 91d for driving a center core push arm 99 (to be described later), an insertion door control arm (to be described later), and a slanted part 91e for driving (to be described later) on its upper end. A control bin 91f for driving a gear arm for opening and closing the door is installed.

On the other hand, the right control plate 93 also has an I-id groove 9 in the front-rear direction.
3g is provided, and the guide bin 79b of the right side plate 79 is slidably fitted into the j-id groove 93a, so that the right control plate 9
3 is supported by the right side plate 79 so as to be slidable in the front and rear direction, and a pinion 97 fixed to the control shaft 67 is engaged with a rack 93b formed at the lower end of the right control plate 93, so that the loading motor 65 is operated. Right control board 9
3 is driven in the front-rear direction in synchronization with the left control plate 91.

In addition, an inclined guide groove 93c is similarly formed in the right control plate 93, and one of the guide shirts 83a of the right holder 83 passes through the holder guide groove 79a of the right side plate 79 and is guided through the rowia 83c. By fitting into the groove 93c, the right holder 83 moves back and forth and up and down along the holder guide @ 79a due to the back and forth movement of the right control plate 93. Further, the right control plate 93 has an inclined portion 93d for driving a regulating plate support arm 101 (described later) and an inclined portion 93e for driving an insertion door control arm (described later) at its upper end.

On the other hand, the loading motor 55 is mounted on the chassis 25.
Above, a center push arm 99 and a regulating plate support arm 101 are mounted on support shafts 103 and 105 so as to be rotatable, and each is supported by a torsion coil spring 1o.
The tip is biased toward the spintal motor 2 by 7°109. As shown in FIG. 10, which is a perspective view of that part, a center core pushing member 111 made of a spring material is fixed to the tip of the center core pushing arm 99.

The tip of the center core pushing member 111 is connected to the spindle motor 2
K is located above the rotation axis of 7 and presses the center core 29 of the magnetic sheet 13 against the chucking magnet 31 of the spindle motor 27 by the spring force of the spring 107.
It has become. A pin 113 that engages with the inclined portion 91d of the left control plate 91 is installed on the side of the center core push arm 99. When the left control plate 91 is located forward (the state shown in FIG. 4), this bottle 113 comes into contact with the upper end of the left control plate 91 and pushes the center core push arm 9'9 against the spring force of the spring 107. The center core pushing member 111 is then rotated in a direction in which it is separated from the spindle motor 27. On the other hand, as the left control plate 91 moves rearward, the bin 113 descends on its inclined portion 91d, and as a result, the center core pushing member 111 descends to push the center core, and the left control plate 91 moves to the farthest backward position. The bottle 113 rides on the stepped portion 91g of the inclined portion 91d, and the center core pushing member 111 is slightly separated from the center core 29 of the magnetic sheet 13.

Further, a regulating plate plate 115 is pivotally supported at the tip of the regulating plate support arm 101, and a regulating plate plate 115 is pivotally supported at the tip of the regulating plate support arm 101.
A regulation plate 117 for regulating the position (i) of the magnetic sheet 13 with respect to the magnetic head 33 is fixed to the lower surface of the magnetic saw 13, facing the magnetic head 33.

The above-mentioned right control plate 93 is attached to the side of the regulation plate support arm 101.
A bottle 119 that engages with the 1\ oblique portion 93d is implanted. When the right control plate 93 is located forward, this bin 119 also comes into contact with the upper end of the right ffTlI n plate 93 and rotates the regulation plate support arm 101 so that the regulation plate 117 is separated from the spindle motor 27. On the other hand, as the right control moves rearward, the bin 119 descends its slope 93d, and the regulation plate grate 115 moves toward the spindle motor 27.
When the regulating plate grate 115 comes into contact with the stone 121 provided on the chassis 25 side, the regulating plate 1
17 is positioned at a predetermined position.

On the other hand, an insertion port door 123 is attached to the rotational magnetic 7 unit 70 pack insertion port 9 so as to be openable and closable. As shown in FIG. 11, which is a perspective view of the insertion door portion, the insertion door 123 has a vertical plate 123a and a horizontal plate 123 that are at right angles to each other.
It has an L-shaped cross section consisting of b, and its left and right ends are connected to left and right insertion door control arms 125.
7, and is biased by a torsion coil spring 129 against the arms 125, 127 in the direction of the arrow in FIG. Left and right insertion slot door control arms 125°1
27 are rotatably supported by guide pins 77c and 79b of the left and right side plates 77 and 79, respectively. The left and right insertion door control arms 125.127 are formed with bent protrusions 125a and 127a that engage with the inclined portions 91e and 93e of the left and right control plates 91 and 93, respectively. Tension coil springs 131.127 and left and right side plates 77 and 79 are provided, respectively.
133 are stretched and their protrusions 125a, 127a
are pressed by the inclined portions 91e and 93e, respectively. Further, a guide pin 77c of the left side plate 77 is rotatably supported by a gear arm 135 for opening and closing the door, and a sector gear 1 is mounted at the tip of the door opening and closing gear arm 135.
35a is formed and meshes with a sector gear 137 provided on the insertion door 123 concentrically with its rotation center. Further, the door opening/closing gear arm 135 has a stepped portion 135b that engages with the control pin 91f of the left control plate 91 described above.
is formed. Therefore, when the left and right control plates 91 and 93 are located in the front, the insertion door 123
3a closes the pack insertion slot 9, but the left and right control plates 9
1.93 moves backwards, the insertion door control arm 1
25°127 are the protrusions 125 a and 127 respectively
a is the inclined portion 91e of the left and right control plates 91.93.

By lowering 93e, it rotates and closes the insertion slot door 12.
When the fulcrum of No. 3 is moved to the top, K, the insertion slot door 123
is rotated 90' and its horizontal plate 123a is inserted into the insertion slot 9.
In the closed state, the control pin 91f of the left control plate 91 engages with the stepped portion 135b of the door opening/closing gear arm 1350, whereby the door is locked.

In the above-mentioned electronic still camera, magnetic sheet /41
When loading the pack 11, push open the insertion slot door 123 with the magnetic notebook/four clip 11 and insert the magnetic sheet pack 11 from the pack insertion slot 9. The magnetic jack 11 is attached to the pack holding part 83 b-f of the right holder 83.
When you arrive... The load detection switch 85 is actuated, thereby starting the loading motor 65 and moving the left and right control plates 91.
Move 93 backwards. Then, the left and right control board 91.9
Due to the movement of step 3, the magnetic sheet/gutsuku 11 moves to the right holder 83.
Then, both the left and right holders 81 and 83 descend toward the spindle motor 27, and the center core 29 of the magnetic sheet 13 is inserted into the rotating shaft of the spindle motor 27. Thereafter, due to the movement of the left and right control plates 91 and 93, the center core pushing arm 99 is actuated to push the center core by the center core pushing member 111, and the regulating plate support arm 101 is actuated to position the regulating plate 117 at a predetermined position. Then, the puncture insertion port 9 is closed by the insertion port door 123, and the loading is completed.

Next, when recording or reproducing, the spindle motor 59
When the cam 53 is rotated at a reduced speed by α rotation, the arm 47 and the carriage 35 move along the guide shaft 39, and the magnetic head 33 is sent in the radial direction of the magnetic sheet 13 and positioned.

Furthermore, the electronic still camera according to this embodiment may be dropped or
Even when vibration is applied, no large impact force is applied to the cam 53. For example, when a collision occurs, an impact force proportional to the stratum of each member acts on each member, so in the past, a large impact force is instantaneously transmitted to the cam, which has a large mass and is in contact with a movable carriage, and the cam A recess was to be formed in the

In contrast, in the present application, when an impact force is applied to the carriage 35, as shown in FIG. The left side plate 77 becomes a stone 4 and is regulated) and the arm 47 rotates around the pin 49, so the force transmitted from the carriage 35 to the cam 53 via the arm 47 and the cam follower 45 is , is the sum of a relatively small impact force due to the mass of a part of the arm 47 and the cam follower 45, and the acting force of the torsion coil spring 51. Therefore, the magnitude of this force is the same as that of the conventional configuration.
That is, the impact force is smaller than that of an integrated carriage and cam follower, and therefore no recess is formed in the cam 53. In the above embodiment, the torsion coil spring 51 is used as the spring when the impact force is applied, but the present invention is not limited to this, and various types of springs can be used. Further, although the guide shaft 39 is fixed to the carriage 35, the guide shaft 39 is not limited to this, and may be fixed to the chassis 25, or two guide shafts may be used instead of one.

Next, a second embodiment will be described with reference to FIGS. 12 and 13.

As shown in both figures, this embodiment
7201 The slightly attached cam follower rod 202 is not rotatably attached to the head carriage 203 but is slidably attached. That is, the head caliper horn 203 is attached to the guide shaft 204, 205.
is slidably supported, and an oil-less metal 2 is provided between the guide shaft 205 and the head carriage 203.
06 is interposed. The head carriage 203 has
A cam follower rod 202 is slidably fitted along a guide shaft 205, and a shock-reducing spring 207 is pressed against the outer periphery of the guide shaft 205 at this fitting portion. Cam 7 ;lr o 7 o rad 202
Further, one end of a tension spring 208 stretched along the idle shaft 205 is connected to the cam follower 201 attached to the cam follower rod 202.
It is designed to be pressed against 09.

Therefore, under normal conditions, when the cam 209 is rotated, the cam follower 2o1° cam follower rod 2 comes into sliding contact with the cam 209.
The cam follower rod 20 and the head carriage 203 move together along the guide shafts 204 and 205, and in the event of a fall, etc., the cam follower rod 20
2, the head carriage 203 moves downward in FIG. 12 and the shock-absorbing spring 207 is compressed.
No large impact force acts on the cam 209. In addition, in the figure,
210 is a magnetic head, and 211 is a stepping motor.

Next, a third embodiment will be described with reference to FIGS. 14 and 15.

As shown in both figures, in this embodiment, a head carriage (hereinafter referred to as a head arm in this embodiment) 212 does not move linearly but rotates about one point.

That is, the main chassis 213 has four sub-chassis 214.
They are supported through book supports 215 and fixed with screws 216, respectively. A spindle motor 217 is placed on the sub-chassis 7214, and the sub-chassis 214
A cam 218 and a spur gear 219 coaxially integrated with the cam 218 are rotatably provided concentrically with the spindle shaft between the main chassis 213 and a stepping motor 221 that rotates a pinion '220 that meshes with the spur gear 219. is fixed on the back of the

On the other hand, the main shear is erected at 7213! 1. pillar 22
2, the head arm 212 is pivoted to the rotary town 1j, and the E
It is fixed with IJ song 23. head arm 2
A cam follower arm 224 is pivotally supported from the center of the back surface of the cam follower 12, and a threaded coil spring 225 is attached to this pivot point to press the cam follower arm 224 against the straight shaft 226. The cam follower arm 224 is provided with an adjustment screw 227 that comes into contact with the stopper 226.
By adjusting the amount of protrusion of the adjustment screw 227, the position of the magnetic head 228 can be finely adjusted.

A tension spring 229 is stretched between the head arm 212 and the subchassis 214, so that the cam follower 23 attached to the cam follower arm 224
0 is pressed against the cam 218.

Therefore, under normal conditions, the stepping motor 221 rotates the pinion 220, and the spur gear 220 that meshes with the pinion 220 is rotated by the stepping motor 221.
19 and the integrated cam 218 rotates, the cam follower 230, cam follower arm 224, and head arm 212 that slide into contact with the cam 218Vc rotate together around the support 222. , the torsion coil spring 225 functions as a shock-reducing spring.

Since the head arm 212 rotates against the spring 225 and hits the stones 231, no large impact force is applied to the cam 218.

<Effects of the Invention> As described above in detail based on the embodiments, according to the present invention, the arm to which the cam follower 1ira is attached and the head carriage are not fixed to each other, and the impact force relieving spring Since it is only biased, it is possible to reduce the impact force transmitted from the head carriage to the cam via the arm when an impact force is applied.

[Brief explanation of drawings]

1 and 2 relate to one embodiment of the present invention, and FIG.
a) is a plan view showing how the carriage moves following the cam, Fig. 1 and others) are plan views showing the movement of the carriage and rotation of the arm when an impact force is applied, and Fig. 2 is a partially cross-sectional view. 3 is a schematic perspective view of an electronic camera body and a magnetic seat back according to an embodiment of the present invention, FIG. 4 is a perspective view of a rotating magnetic sheet device shown together with the magnetic sheet pack, and FIG. The figure is an exploded perspective view of the main parts, Figure 6 is a perspective view of the cam gear part, Figure 7 is a perspective view of the left and right side plates, Figure 8 is a perspective view of the left and right holders, and Figure 9 is the left and right control. A perspective view of the plate, FIG. 410 is a perspective view of the center core push arm and the regulating plate support arm portion, FIG. 11 is a perspective view of the insertion door portion, and FIG. 12 is a partial view of the second embodiment of the present invention. Front view shown in section, No. 13
The figures are a sectional view taken along the line A--A in FIG. 12, FIG. 14 is a front view of the third embodiment of the present invention, and FIG. 15 is a view taken along the line B--B in FIG. 14. In the drawing, 33 is a head, 35 is a carriage, 37 is a tension spring, 39 is a guide shaft, 45 is a cam follower, 47 is an arm, and 51 is a torsion coil spring.

Claims (1)

[Claims] A head carriage to which a magnetic head is attached is brought into contact with a cam via a cam follower attached to the head carriage, and the cam is rotationally driven.
In the feed drive device capable of moving the head carriage, the cam follower causes the cam follower and the head carriage to move when a force of a predetermined amount or more is applied to the head carriage in the moving direction of the head carriage. An impact force alleviation device for a cam, characterized in that the device is attached to the head carriage via an elastic member so as to be relatively movable.