JPS5914921Y2 - Reel shaft rotation mechanism of recording/playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reel shaft rotation mechanism for a recording/reproducing device, which is an improved reel shaft having a slip mechanism.

For example, when a tape recorder is set to play, the magnetic tape is always fed out at a constant speed by a pinch roller and a capstan toward a reel hub engaged with a take-up reel shaft rotation mechanism.

As the reel bubble winds up the sent-out magnetic tape, its winding diameter gradually increases.

Therefore, it is necessary to gradually reduce the number of revolutions of the reel hub in order to wind the magnetic tape, which is always sent out at a constant speed, onto the reel hub in the best possible condition.

Conventionally, this objective has been achieved using a reel shaft rotation mechanism as shown in FIG.

That is, this reel shaft rotation mechanism has the following configuration.

A collar C is provided at the upper end of the reel shaft a and is movable up and down and has a driving claw.

A pulley d is fixed to the lower end so as to rotate together with the reel shaft a, and a boot IJ-f to which a felt e is attached is loosely fitted under the pulley d so as to be rotatable with respect to the reel shaft a. It is.

This pool -f is urged in the direction of the pulley d by a coil spring i on a cap h supported by an E ring g fitted on the reel shaft.

j is a bearing for the reel shaft a, and is fixed to the substrate 1 by a screw passed through a hole k.

In a tape recorder using such a reel shaft rotation mechanism, the magnetic tape is always fed out at a constant speed by the pinch roller and capstan, and is wound onto the reel hub fitted with the collar.

The power for this winding is obtained from an electric motor, which rotates a pulley f via an idler etc., and this rotation is transmitted to a pulley d via a felt (e), and a pulley d
It is transmitted to the reel hub via the collar -C on the reel shaft a, which is integral with the reel shaft a.

In this case, the electric motor always maintains a constant number of revolutions and rotates the pulley f, but the IJ-1, which winds the magnetic tape fed out at a constant speed by the pinch roller and capstan,
The number of rotations of the hub is limited by the magnetic tape being sent out.

Therefore, as the diameter of the magnetic tape wound around the reel hub increases, the difference in rotational speed between the reel hub and pulley 4 increases, and this difference is absorbed by the slip between pulley d and pulley f. be.

At this time, the problem is the slip that occurs between pulley d and pulley 1.

As shown in the figure, a coil spring i is inserted between a pulley f and a cap h supported by an E ring g near the reel shaft aL, and the upper end of the coil spring i is connected to the pulley f, and the lower end is connected to the cap h. There are things that are in contact with each other.

Therefore, if there is a slip between pulley d and pulley 1,
The upper end of the coil spring i rotates following the pulley f, and the lower end of the coil spring i rotates following the cap h, so that the coil spring i receives a torsional moment.

As a result, when the energy accumulated in the coil spring i exceeds the contact friction force at both ends of the coil spring 19771, part or all of this energy is transmitted to the reel shaft a through the cap h and the E-ring g, and the reel shaft is irregular. make a rotation.

Vibrations are applied to the magnetic tape through this irregularly rotating beam hub, which also induces "uneven running" of the magnetic tape, degrading the recording or playback characteristics.

Furthermore, during the rotation of the reel shaft, an unpleasant sound is produced due to slips between the spring i and the cap h, and between the pulley f and the spring i.

The purpose of the present invention is to provide a reel shaft rotation mechanism for a recording/reproducing device that eliminates the above-mentioned drawbacks, and the gist thereof is to provide a reel shaft rotatably supported and a first reel shaft pulley fixed to the reel shaft. and is rotatably mounted on the reel shaft, and has one main surface facing the first reel shaft boot 9- and is frictionally coupled to the same so as to be able to slip thereon, and has an annular recess (or protrusion) on the other main surface. A second reel shaft pulley is provided with a plurality of concave portions (or convex portions) at predetermined intervals so as to be a part of the second reel shaft pulley, and is formed to be rotationally driven using the side surface thereof during recording or playback mode. and a plurality of recesses (or protrusions) rotatably attached to the reel shaft on the other main surface side of the second reel shaft pulley and formed on the other main surface of the second reel shaft pulley. A plurality of convex portions (or concave portions) that can be fitted are formed on one main surface thereof to allow displacement of the second reel shaft pulley in the axial direction, but are integrated with the second reel shaft pulley. a driven body rotatably coupled to the second reel shaft pulley; a stopper adjustable and fixed to the reel shaft on the other main surface side of the driven body; the second reel shaft pulley; and the driven member. and an elastic member disposed between the body and the second reel shaft pulley to apply an elastic biasing force in one direction to the first reel shaft pulley. It is in the reel shaft rotation mechanism of the playback device.

The present invention will be described in detail below according to one embodiment of the present invention.

1 is a bearing for the reel shaft 2, which is located in the hole 4 with respect to the substrate 3.
It is screwed in with a screw (not shown) passed through.

The reel shaft 2 is rotatably supported on a bearing 1 via an oilless metal 5, and a guide body 8 having a flange 6 is fixedly attached to the upper part thereof.

The guide body 8 has a collar 1 having a drive claw 9 that can be moved up and down.
A coil spring 12 is interposed between the collar 10 and the flange 6 to bias the collar 10 toward the stopper 11.

Of course, the collar 10 moves up and down on the guide body 8, but does not rotate idly relative to the guide body 8.

A stopper 13 is located below the bearing 1 on the reel shaft 2.
Biasing means 1 consisting of a driven body 14 and a coil spring 15
6 is the arrangement.

The stopper 13 is attached to the bearing 1 on the reel shaft 2 by a screw 13a.
The driven body 14 is rotatably fitted loosely onto the reel shaft 2 through the screwed hole 17, and the coil spring 15 is inserted thereinto.

Furthermore, after the coil spring 15 is inserted, the boo 9-18 is loosely fitted from below the reel shaft 2 through the hole 19 so that the spring 15 is compressed and held between the driven body 14 and the second reel shaft pulley 18. It is.

At this time, a convex portion 20 formed on one main surface of the driven body 14
．． 21 and the second reel shaft pulley 18 are inserted so that the recesses 22 and 23 formed on the other main surface of the second reel shaft pulley 18 fit into each other.

After the second reel shaft pulley 18 is loosely fitted, the first reel shaft pulley 25 to which the annular felt 24 is attached is press-fitted and fixed onto the reel shaft 2.

By press-fitting and fixing the first reel shaft pulley 25, the coil spring 15 is maintained in a compressed state between the driven body 14 and the second reel shaft pulley 18.

Therefore, one main surface of the second reel shaft pulley 18 is always pressed against the first reel shaft pulley 25.

Note that the driven body 14, the second reel shaft pulley 18, and the first
The reel shaft pulleys 25 are each molded from plastic.

Further, the screw 13a in the stopper 13 is connected to the second reel shaft pulley 18 with respect to the first reel shaft pulley 25.
It is used to fix the stopper 13 at an arbitrary position on the reel shaft 2 in order to adjust the pressing force of the stopper 13.

One embodiment of the reel shaft rotation mechanism of the recording and reproducing apparatus according to the present invention has the above-mentioned configuration, and its operation will be explained below. During fast forwarding or rewinding, the belt is Or the first via an idler (not shown) etc.
When the reel shaft pulley 25 is rotationally driven, the guide body 8 rotates via the reel shaft 2, and the reel hub (not shown) fitted with the collar 1'o integrated with the guide body 8 also rotates. The magnetic tape is wound at high speed from the reel hub, and fast-forwarding or rewinding is performed.

During this fast forwarding and rewinding, the second reel shaft pulley 18 merely rotates following the first reel shaft pulley 25 by the pressing force of the coil spring 15.

On the other hand, during reproduction and recording, the motor rotates the second reel shaft pulley 18 using its side surface via a belt or an idler (not shown).

This rotation rotates the first reel shaft pulley 9-25 because the second reel shaft pulley T18 is in frictional contact with the first reel shaft pulley 25 via the felt 24 due to the coil spring 15.

This rotation is performed on the reel shaft 2 in the same way as in the case of fast forwarding and rewinding.
The signal is transmitted to a guide body 8, a collar 10, and a reel hub (not shown) fitted with the collar 10, and the reel hub is driven by a pinch roller and a capstan at a constant speed from a reel hub (not shown) on the supply side. The supplied magnetic tape is wound without slack, and recording or reproduction is performed.

The reason why the reel hub fitted with the collar 10 winds up the magnetic tape without this slack is due to the following action.

That is, the traveling speed of the magnetic tape fed out by the capstan and the pinch roller is constant, and as the magnetic tape is wound, the winding diameter of the reel hub fitted with the collar 10 gradually increases.

Therefore, in order to wind this magnetic tape without slack, it is necessary to gradually reduce the number of rotations of the beam-rehab.

However, the number of rotations of the second reel shaft pulley rotated by the electric motor is constant.

The difference in rotational speed that occurs between the reel hub and the second reel shaft pulley 18 is absorbed by the slip between the first reel shaft pulley 25 and the second reel shaft pulley 18, and the reel hub fitted to the collar 10 moves as expected. It rotates at a rotational speed of , and winds the magnetic tape without slack.

Incidentally, in any of the above cases of fast forwarding, rewinding, playback, and recording, the driven body 14 has its convex portion 20.21 engaged with the concave portion 22.23 of the second reel shaft pulley 18. Therefore, it always rotates integrally with the second reel shaft pulley.

Therefore, no torsional moment is generated in the coil spring 15, which contacts the driven body 14 at one end and the second reel shaft pulley 18 at the other end.

Further, as described above, the driven body 14, the first reel shaft pulley 2
5. Each of the second reel shaft pulleys 18 is injection molded from plastic, which can be manufactured at a lower cost than metal, and to avoid metal noises generated from sliding parts. It is.

Although the coil spring 15 is used as part of the biasing means in the above embodiment, the present invention is not limited to a coil spring, and may be a leaf spring, for example.

Also, the second reel shaft pulley 18 was provided with recesses 22 and 23, and the driven member 14 was provided with protrusions 20 and 21, but conversely, the second reel shaft pulley was provided with a protrusion, and the driven member was provided with a protrusion. A concave portion may be formed in 14, and the present invention is not limited thereto.

As described above, the reel shaft rotation mechanism of the recording/reproducing apparatus according to the present invention presses the second reel shaft pulley onto the first reel shaft pulley by the urging means integrated with the second reel shaft pulley. This has the effect that no torsional moment is generated in the urging means, the magnetic tape can be run in the best condition for recording and reproduction, and unpleasant noises caused by slipping of the warning means can also be prevented.

Furthermore, the fitting operation between the convex portion and the concave portion formed on one main surface of the driven body and the other main surface of the second reel shaft pulley is performed simply by lightly pressing them together and relatively Since all you have to do is rotate it, there is no need for complicated work such as carefully observing it.

Therefore, it is easy to manufacture and has the effect of improving productivity.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a partially cutaway front view of a reel shaft rotation mechanism of a conventional recording/reproducing device, and FIG. 2 is a partially cutaway front view showing an embodiment of the present invention. FIG. 3 is a bottom view showing a driven member in the urging means, and FIG. 4 is a plan view showing the second reel shaft pulley in FIG. 2.

Claims (1)

[Claims for Utility Model Registration] A reel shaft rotatably supported, a first reel shaft pulley fixed to the reel shaft, and a first reel shaft pulley rotatably attached to the reel shaft. A plurality of recesses (or protrusions) at predetermined intervals, with one main surface facing each other and frictionally coupled to the other main surface so as to be slippery, and forming a part of an annular recess (or protrusion) on the other main surface. a second reel shaft pulley, which is provided with a second reel shaft pulley and is formed to be rotationally driven using its side surface during recording or playback mode; a plurality of recesses (or protrusions) rotatably mounted on the second reel shaft pulley and formed on the other main surface of the second reel shaft pulley;
A plurality of convex portions (or concave portions) that can be fitted with the second reel shaft pulley are formed on one main surface thereof to allow displacement of the second reel shaft pulley in the axial direction, but the second reel shaft pulley is integrated with the second reel shaft pulley. a driven body coupled to the second reel shaft pulley so as to rotate; a stopper adjustable and fixed to the reel shaft on the other main surface side of the driven body; and a second line shaft pulley. an elastic member disposed between the driven member and the elastic member configured to elastically bias the first reel shaft pulley in one direction with respect to the second reel shaft pulley; A reel shaft rotation mechanism of a recording/playback device.