JPH01201853A - Transmission mechanism for driving reel turntable of tape recorder - Google Patents

Abstract

PURPOSE:To reduce the number of components and to improve operability by setting a ratio of the reduction ratio of a supply side gear train to that of a take-up side gear train equal to the ratio of torque required for tape winding in a reproduction mode to that in a reverse reproduction mode. CONSTITUTION:At the time of reproduction, a tape 31 is taken up on a reel 35 by rotating an output pulley 26 in a counterclockwise direction, and driving the take-up side A gear train via a driving pulley 21, a driving gear 25, and a rocking arm 13. Meanwhile, at the time of reverse reproduction, the tape 31 is taken up on a reel 34 by rotating a pulley 26 in a clockwise direction, and driving the supply side B gear train by turning an arm 13 in the clockwise direction. And in the reproduction and reverse reproduction modes, a difference is generated in tape tension. Therefore, the ratio of the reduction ratio by the A side gear train to that by the B side gear train is set equal to the ratio of the torque required for the winding of the tape in the reproduction mode to that in the reverse reproduction mode. In such a way, it is possible to make a clutch mechanism at every reel board unnecessary, and to improve assembling work by reducing the number of components.

Description

DETAILED DESCRIPTION OF THE INVENTION The reel stand drive transmission mechanism of the tape recorder of the present invention will be explained according to the following items.

A6 Industrial field of application B1 Summary of the invention C3 Prior art a, general background b, necessity of reverse playback mode C0 Conventional example [Figures 5 and 6 D0 Problems to be solved by the invention E9 Problems Means F for solving the problem, Examples [Figs. 1 to 4] a. Reel stand [Figs. 1, 2, and 4] b. Intermediate gear [Figs. 1, 2, and 4] Figure 4] C0 swing arm [Figure 1,
[Fig. 3, Fig. 4] d. Drive unit [Fig. 1, Fig. 3, Fig. 4] e. Others [Fig. 1, Fig. 4] f0 action [Fig. 4] g. Specific numerical examples G0 Effects of the Invention (A. Field of Industrial Application) The present invention relates to a novel tape recorder reel stand drive transmission mechanism. Specifically, it relates to a one-knob drive transmission mechanism in a tape recorder that runs a tape in a playback mode and a reverse playback mode using a single capstan shaft. Considering that there is a difference in tape tension, the reduction ratios of the supply side gear train, which transmits drive from the drive gear to the supply side reel stand, and the take-up side gear train, which transmits drive to the take-up side reel stand, are determined. It is an object of the present invention to provide a novel reel stand drive transmission mechanism for a tape recorder in which the output torques of the supply side reel stand and the take-up side reel stand are made different.

(B. Summary of the Invention) The reel stand drive transmission mechanism of the tape recorder of the present invention transfers the rotation of one drive gear to the supply side (hereinafter referred to as "S side"), the reel stand or the winding side (hereinafter referred to as rT side). ) The ratio of the reduction ratios of the S-side gear train or the T-side gear train, which are transmitted separately to the reel stand, is determined by the torque required for winding the tape on the T-side reel stand in the playback mode and the reverse playback. S in mode
By making the ratio approximately equal to the torque required for winding the tape on the side reel stand, it is possible to easily wind the tape on each of the S side reel stand and the T side reel stand without increasing the number of parts. This makes it possible to achieve the necessary output torque.

(C, Prior Art) (a-General Background) A tape recorder runs the tape using a capstan shaft, and winds up the tape sent out by the capstan shaft using a reel stand. The T-side reel stand rotates, and in the reverse playback mode, the S-side reel stand rotates to wind up the tape fed out by the capstan shaft.

As the tape is wound onto each reel stand, the diameter of the tape increases, and if the number of rotations were the same, the winding speed would increase, so normally each reel stand and each reel stand gear A clutch mechanism is constructed by interposing a friction plate between the reel stand and the reel stand gear to relatively press them together, and when a load is applied to the reel stand, the friction plate slides, reducing the output torque of the reel stand gear. is transmitted to the reel stand in such a way that it can respond to changes in the tape winding diameter.

In addition, in a tape recorder that performs playback and reverse playback using a single capstan shaft, the capstan shaft is disposed between the head and the T-side slider, and the capstan shaft is disposed between the head and the T-side slider, and the capstan shaft is unrolled from the tape cassette in the playback mode. The tape runs in the order of S side reel - tape guide - head - tape guide - cab stun shaft - D side reel. Also, in the reverse playback mode, the tape that runs out from the tape cassette runs in the following order:
T side - Capstan shaft - Tape guide - Head -
Because the tape guide runs in the order of the S-side reel, the tape tension that occurs from the capstan axis to the S-side reel during reverse playback is greater than the tape tension that occurs between the capstan axis and the T-side reel during playback. is larger, and therefore, the winding torque of the S side reel stand during reverse playback must be made larger than the winding torque of the T side reel stand during playback.

Therefore, conventionally, the resiliency force of the crimping means for crimping each reel stand and reel stand gear is different, and one with a large elastic force is used on the S side, and one with a large elastic force is used on the T side. The output torque of the S side reel stand was increased by using one with low power generation.

(b. Necessity of reverse playback mode) Tape recorders that require a playback mode and a reverse playback mode are not limited to audio tape recorders, but video tape recorders and digital audio recorders also have a reverse playback mode in addition to the playback mode. is necessary.

That is, in addition to the normal playback function, the reverse playback mode in an audio tape recorder is necessary to realize the so-called reverse function in which the tape is played back by running the tape in the opposite direction to the normal playback direction. The playback mode in a video cheap recorder is necessary to realize the reverse playback function that allows you to reverse the image, and the reverse playback mode in a digital audio tape recorder is necessary to find the beginning of a recorded song. The so-called auto music scan function detects tD scratch signals by running the tape in the forward or reverse direction at high speed (200 to 300 times the normal speed) or medium speed (10 to 20 times the normal speed). is necessary to achieve this.

In any of the above cases, in such a tape recorder, it is necessary for the head to detect the signal recorded on the tape in both playback mode and reverse playback mode.
Therefore, it is necessary to run the tape using the capstan shaft and to bring the tape into contact with the head.

(c. Conventional example) [Figs. 5 and 6] Figs. 5 and 6 show an example a of a conventional tape recorder reel stand drive transmission mechanism having such a configuration.

b4 and C are reel stands rotatably supported by a chassis (not shown), and the one on the left side in Fig. 5 is S.
There is a one-person stool on the side, and the one on the right is the T-side stool.

d is a reel stand gear of the S side reel stand, e is a reel stand gear of the T side reel stand C, and both reel stand gears d and e have the same pitch circle diameter. Furthermore, a friction plate f is provided between the S side reel stand and the S side reel stand gear d, and a friction plate g is provided between the T side reel stand C and the T side reel stand gear e. are interposed, respectively, and coil springs h and 1 are provided so that each reel stand c and reel stand gear d1e are pressed together via friction plates f and g, respectively. In addition, the coil springs h and i are set such that the elastic force of the coil spring h (s side coil spring) is larger, and the output torque of the S side reel stand is larger than the output torque of the T side reel stand C. It's supposed to be.

j is a support shaft erected from the chassis, and the support shaft j
A drive gear l and a swing arm m are rotatably supported on the drive pulley, and the drive pulley and the drive gear are integrally formed, and the drive pulley moves as the belt runs, which will be described later. The drive gear 2 is configured to rotate.

n is a swing gear rotatably supported on the swing 5ij and i portion of the swing arm m, and the swing gear n is connected to the drive gear 1.
A friction plate made of felt or the like is provided between the top surface of the swing gear n and the bottom surface of the swing arm m.
is interposed, and the swing gear n is always pressed against the swing arm m via the friction plate 0 by a resilient member (not shown).

p is an intermediate gear on the s side, and is rotatably supported by a gear support shaft q installed upright on the chassis, and the intermediate gear p is always in mesh with the sole stand gear d on the S side, and It is designed to mesh with the moving gear n.

r is a T-side intermediate gear having the same diameter as the S-side intermediate gear p, and is rotatably supported by a gear support shaft S installed upright on the chassis, and the T-side intermediate gear r is always on the T side. It meshes with the round gear e and can also mesh with the swing gear n.

t is an output pulley fixed to the output shaft of a motor (not shown), and a belt pulley is suspended between the output pulley t and the drive pulley.

When the reproduction mode is selected, the rotation of the drive motor is transmitted to the reel stand in the following manner.

First, when the output pulley t rotates counterclockwise, the belt U runs in the direction of arrow X, causing the drive pulley k and drive gear ρ to rotate counterclockwise. When the drive gear l is rotated counterclockwise, the swing arm m swings in the same direction as the drive gear 1, and the swing gear n at the swing end meshes with the T-drive intermediate gear r. .

That is, since the swing gear n is pressed against the swing arm m via the friction plate 0, it does not rotate when the drive gear 2 starts rotating counterclockwise, but rotates in the direction of rotation of the drive gear l. Along with the swinging arm m, there is also a driving gear! The oscillating gear n meshes with the T-shaped intermediate gear r.

When the swing gear n meshes with the intermediate gear r, the revolution is blocked by this mesh, and the swing gear n rotates clockwise due to the counterclockwise rotation of the drive gear ρ. The intermediate gear 1 is rotated counterclockwise, and the T-side slide gear e is further rotated clockwise.

The rotation of the T-side rail stand gear e causes the T-side rail stand C to rotate in the same direction via the friction plate g, and as the T-side rail stand C rotates clockwise, the installation is completed. Tape cassette ■
The T-side wheel W is rotated in the winding direction of the tape X.

At the same time, a capstan shaft (not shown) is rotated, causing the tape X to travel in the forward direction at a constant speed, thereby feeding the tape X toward the T side and the W side. Then, the aforementioned T-side wheel W rotates in the winding direction, thereby winding up the tape X fed out from the capstan shaft.

When the reverse playback mode is selected, the output pulley t rotates clockwise, the belt U runs in the opposite direction to the arrow X direction, and the drive pulley k and drive gear 1 rotate clockwise. , the swinging end of the swinging arm m is rotated toward the S-drive intermediate gear p side.

Then, the rotation of the drive gear 1 is transmitted to the S side slider stand d via the +8 moving gear n-3 side intermediate gear p, which rotates the S side slider y of the attached tape cassette V. The tape X fed out by the stand shaft is wound up by the S side loop y.

Ru.

By the way, the output torque of the T-side reel stand C and the output torque of the S-side reel stand in the playback mode and the reverse playback mode are as follows: The coil spring i on the T side is attached to the coil spring h that is crimped to the stand.
Since it uses a material with stronger elasticity than the S side reel stand, the output torque of the S side reel stand is larger.
Even if the tape tension in the reverse playback mode is greater than the tape tension in the playback mode, the tape X will not loosen in the reverse playback mode and the tape X can be moved to the S side
It can be rolled up into a circle.

(D. Problem that the invention seeks to solve) However,
In the conventional reel stand drive transmission mechanism a of the tape recorder described above, in order to provide a difference in output torque between the S side reel stand and the T side reel stand C, the reel stand c, Reel stand gears d, e, friction plates f, g, and coil spring h11
Since two clutch mechanisms are used, and the pressure force (elastic force of coil springs h and i) is different from each other, the number of parts is large and the structure is complicated. When assembling the coil spring h
There is a risk of assembling the coil spring i and the coil spring i by mistake, and therefore, there is a problem that the workability is extremely poor.

In addition, the torque transmission of the clutch mechanism decreases over time, making it unstable as a drive transmission means and requiring the use of latch mechanisms in two locations. There was a problem that made the power transmission to the stand unstable.

(E. Means for Solving the Problems) Therefore, in order to solve the above-mentioned problems, in the reel stand drive transmission device of the tape recorder of the present invention, the drive gear is interposed between the drive gear and the drive source. It is equipped with a clutch mechanism that slips when a load is applied to the side, and separate gear trains that transmit the rotation of the drive gear to the S reel stand or the lower reel stand. The ratio of the reduction ratio by the side gear train is made to be approximately equal to the ratio of the torque required for winding the tape by the lower reel stand in the playback mode and the torque required for winding the tape by the S side reel stand in the reverse playback mode. This is what I did.

Therefore, according to the reel stand drive transmission mechanism of the tape recorder of the present invention, there is no need for a clutch mechanism for each sole stand.
The structure can be simplified, the number of parts can be reduced, and incorrect assembly of the clutch mechanism can be prevented, and assembly workability can be improved.

Furthermore, since only one clutch mechanism is used, there is little chance of instability in power transmission due to aging, and this can be kept to a minimum of one problem.

(F. Embodiment) [FIGS. 1 to 4] Details of the reel support/protection transmission mechanism of the tape recorder of the present invention will be described in accordance with Embodiment 1 shown in the accompanying drawings.

In the first embodiment shown in the drawings, the reel drive transmission device of the tape recorder of the present invention is applied to a digital audio recorder.

(a, reel stand) [Fig. 1, Fig. 2, Fig. 4] 2.
Reference numeral 3 denotes a reel stand, which is rotatably supported by a support shaft 5.6 erected from the chassis 4.

The reel stand 2 is an S-side whirl stand, and a spur gear-shaped reel stand gear 7 is integrally formed on the S-side reel stand 2, and the reel stand 3 is a T-side reel stand. A lower reel stand gear 8 having a pitch circle smaller in diameter than the pitch circle of the S side reel stand gear 7 is integrally formed on the lower reel stand 3. Note that the diameter of the pitch circle of each gear will be described later.

(b, intermediate gear) [Fig. 1, Fig. 2, Fig. 4] 9 is an S measuring wheel of the chassis 4 that is rotatably supported on a support shaft 1o that is erected diagonally in front of the right side of the S measuring wheel table 2. This is a side intermediate gear, and is composed of a small diameter gear 91 that is always in mesh with the S side reel base gear 7, and a large diameter gear 92 that is coaxially formed integrally with the lower surface of the small diameter gear 91.

Reference numeral 11 denotes a T-play intermediate gear rotatably supported by a support shaft 12 erected obliquely to the left front of the lower reel stand 3 of the chassis 4, and is a small diameter gear that is always engaged with the lower reel stand gear 8. It is composed of a gear 111 and a large diameter gear 112 coaxially formed integrally with the lower surface of the small diameter gear 111.

In addition, the large diameter gear 9° of the S side intermediate gear 9 and the T play intermediate gear 11
Although it has a pitch circle of the same diameter as the large diameter gear 12,
The pitch circle of the small diameter gear 91 of the S side intermediate gear 9 is the same as the pitch circle of the small diameter gear 11 of the T play intermediate gear 11. It is formed to have a smaller diameter than the pitch circle of. Details will be described later.

(c, swinging arm) [Figures 1, 3, and 4] 13 is a swinging arm, with a support cylinder 14 integrally formed at its base, which is rotatably supported by the chassis 4. It is rotatably supported by a rotating shaft which will be described later.

15 is a swing gear, which includes the tip of the swing arm 13;
In other words, it is rotatably supported by a support shaft 16 that projects downward from the swing end. The swing gear 15 includes a large diameter gear 15 and a small diameter gear 152 integrally formed on the lower surface of the large diameter gear 15. Further, an annular groove 153 is formed on the lower surface of the small diameter gear 152 near its axis.

17 is a flange attached to the lower end of the support shaft 16 that supports the swing gear 15, and a groove 15.17 is formed on the upper surface of the flange 17 and the lower surface of the small diameter gear 152. A coil spring 18 is compressed between the bottom of the large-diameter gear 15 and the swinging arm, so that the swinging gear 15 is biased upwardly. 13 is in constant pressure contact with the lower surface. Then, a moderate amount of friction is generated between the two, that is, a force that rotates the swing arm 13 in a predetermined direction depending on the direction of the moving force applied to the swing gear 15, and the rotation of the swing gear 15 is hindered. It is designed to create a level of friction that cannot be avoided.

(d, Drive Unit) [Figures 1, 3, and 4] Reference numeral 19 is a rotating shaft supported by the chassis 4 in a freely rotatable manner and penetrating through the chassis 4.

20 is a cylindrical portion 20. This is a friction plate with a flange portion 202 integrally formed at one end, and the cylindrical portion 201 of the friction plate 20 is located at the bottom of the rotating shaft 19 (projecting downward from the chassis 4) with the flange portion 2o2 facing upward. part).

21 is a drive pulley, and the cylindrical portion 20 of the friction plate 2o,
It is rotatably fitted on the outside.

Reference numeral 22 denotes an annular friction material made of felt or the like, and is inserted between the opposing surfaces of the friction plate 2o and the drive pulley 21.

23 is the cylindrical portion 20. of the friction plate 2o. This is a cylindrical stopper press-fitted into the lower end of the stopper 23, and the lower end of the stopper 23 has a flange 23. are integrally formed.

A coil spring 24 is compressed between the upper surface of the flange 23 of the stopper 23 and the lower surface of the drive pulley 21. Therefore, the driving pulley 21 is always biased with an upward resilient force, and the flange portion of the friction plate 20 is
0. When the drive pulley 21 rotates,
The friction plate 20 and the rotating shaft 19 rotate through the friction material 22, and also rotate! When a load of more than a certain level is applied to N119, the friction material 22 will close to the friction plate 20 or drive pulley 21.
The rotation of the drive pulley 21 is not transmitted to the friction plate 20 and the rotating shaft 19.

Reference numeral 25 denotes a drive gear, which is press-fitted into the upper part of the rotary shaft 19 (a portion protruding above the chassis 4), so that it rotates with respect to the chassis 4 integrally with the rotary shaft 19.

Further, a support cylinder 14 of the swinging arm 13 is rotatably supported at a portion of the rotating shaft 19 that protrudes above the drive gear 25. Large diameter gear 15 of gear 15. is always meshed with the drive gear 25.

26 is an output pulley, and a support shaft of the output pulley 26 is rotatably supported by the chassis 4. The output pulley 26 is formed integrally with, for example, a friction wheel (not shown), and the output shaft of a drive motor (not shown) comes into contact with the friction wheel, so that the output pulley 26 is rotated by the rotation thereof.

Further, a belt 27 is stretched between the output pulley 26 and the drive pulley 21.

(e, Others) [FIGS. 1 and 4] 28 is a capstan shaft, and the portion of the support shaft of the output pulley 26 that protrudes above the chassis 4 is the capstan shaft 28.

Reference numeral 29 is a pinch roller, which is arranged opposite to the capstan shaft 28, and is used when the capstan is in playback mode and reverse playback mode. 1iI1128, and the tape 31 fed out from the tape cassette 3o is held together with the capstan shaft 28.

32 is a rotating drum placed in front of the reel stand 2.3;
33. 33, . . . are tape loading posts for tape loading, and 34 is a tape cassette 3.
The S-side reel 35 in o is the T-side reel in the tape cassette 3o.

(F, Effect) [Figure 4] When the output pulley 26 rotates counterclockwise next to the reel stand drive transmission device of the tape recorder described above, the belt 27 runs in the direction of the arrow Y, and the drive pulley 2
1 and drive gear 25 in the counterclockwise direction.

At this time, since no load is applied to the drive gear 25, no slipping occurs between the friction material 22, the friction plate 20, and the drive pulley 21, and the rotational force of the drive pulley 21 is transmitted to the drive gear 25. be able to.

As the drive gear 25 rotates counterclockwise, the swing arm 13 is rotated counterclockwise, and the swing gear 15 rotates counterclockwise.
The small diameter gear 15□ is the large diameter gear 112 of the T play intermediate gear 11.
．． It meshes with.

Then, the rotation of the swing arm 13 is prevented by the engagement of the swing gear 15 with the T-stroke intermediate gear 11, and the rotation of the drive gear 25 causes the swing gear 15 to rotate clockwise, so that the T-stroke intermediate gear 11 Rotate counterclockwise, and then measure T.
This causes the wheel base gear 8 and the T side wheel base 24 to rotate clockwise. A gear train is formed by rotating the swinging arm 13 toward the T-side intermediate gear 11, that is, a gear consisting of the swinging gear 15, the T-side intermediate gear 11, and the T-side slide gear 8. This train is hereinafter referred to as T-side gear train A.

This state is the playback mode, and the tape 31 unwound from the freely rotatable S-side reel 34 is run while being sandwiched between the capstan shaft 28 and the pinch roller 29. One rotation drum 3
2-Tape guide 33-Car 7゜The tape 31 is fed out to the T-side thread 35 side through the stun Nakayama 28 and the pinch roller 29, and is rotated by the T-side thread 35 by the T-side thread base 3. It will be taken up.

Note that the winding diameter of the T-side thread 35 increases as the winding progresses, but
Since the feeding speed of the tape 31 is constant, the capstan shaft 28, the pinch roller 29 and the T-side slider 3
When the tape tension between the drive pulley 21 or the friction plate 20 and the friction material 22 increases, the tape tension between the drive pulley 21 or the friction plate 20 and the friction material 22 increases. This prevents an output torque exceeding a certain level from being generated on the T-side stool 3 due to the slipping between the two.

Further, when the output pulley 26 rotates clockwise, the belt 27 runs in the direction of arrow Z, causing the drive pulley 21 and the drive gear 25 to rotate clockwise. As the drive gear 25 rotates clockwise, the swing arm 13 is rotated clockwise, and the small diameter gear 15□ of the swing gear 15 is connected to the large diameter gear 92 of the S side intermediate gear 9. engaged,
The clockwise rotation of the drive gear 25 rotates the swing gear 15 counterclockwise, causing the S-side intermediate gear 9 to rotate clockwise and the S-side reel stand gear 7 and S-side reel stand 2 to move counterclockwise. This will cause it to rotate in the circular direction. In addition, swing arm 1
3 or S side intermediate gear 9 side (114
The gear train that is formed, that is, the swing gear 15, the S side intermediate gear 9
, the S-side reel stand gear 7 is hereinafter referred to as the S-side gear train B.

This state is the reverse playback mode, and the freely rotatable T
The tape 31 fed out from the side rail 35 is held between the capstan φ ridge 28 and the pinch roller 29, and is made to travel between the T side rail 35, the capstan shaft 28, the pinch roller 29, and the tape guide 33. The tape passes through the rotating drum 32 and the tape guide 33, and is then picked up by the S-side reel 34.

Incidentally, when the winding diameter of the S-side reel 34 is expanded, as in the case of the T-side reel 35 described above, slipping occurs between the drive pulley 21 or the friction plate 20 and the friction material 22, causing the S-side reel to The output torque above a certain level is not generated in the stand 2.

(g, specific numerical example) The size of each gear is set as follows.

The output torque required to wind up the tape 31 on the T-side reel stand 3 in the playback mode is 12 g-cm, and the output torque required to wind up the tape 31 on the S-side reel stand 2 in the reverse playback mode is 18 g-cm. −cm. The output torque of each reel stand is determined by the number of tape guides 33, 33, .

Further, if the transmission torque of the friction material 22 is T, the reduction ratio of the T-side gear train A is α, and the reduction ratio of the S-side gear train B is β, then T Ia = 12 g-cm T-β = 18 g-cm Become.

Therefore, α:β=2:3.

Next, set the pitch circle diameter of each gear.

First, the drive gear 25 is set to φ6, and the large diameter gear 1 of the swing gear 15 is set to φ6.
5. φ12, the small diameter gear 152 of the swing gear 15 is φ8,
The large diameter gear 112 of the T play intermediate gear 11 is set to φ8.8, the small diameter gear 111 of the T play intermediate gear 11 is set to φ6.8, and the T side wheel base gear 8 is set to φ8. Also, the pitch circle of the large diameter gear 9□ of the S side intermediate gear 9 is the large diameter gear 11 of the T play intermediate gear]1.
Since it is preferable to make the diameter the same as the diameter of the pitch circle of No. 2, this is set to φ8.8.

Here, the reduction ratio α of the T-side gear train A is: becomes.

Therefore, β=−×α=3.89.

Then, the diameter of the pitch circle of the large diameter gear 92 of the S side intermediate gear 9 and the diameter of the pitch circle of the S side reel stand gear 7 are respectively φD,
It is calculated below as φE.

Since the large diameter gear 8□ of the S side intermediate gear 9 is φ8.8, ・', -= 1.7682
-■Also, the sum of the diameters of the pitch circles of the S side reel base gear 7 and the large diameter gear 92 of the S side intermediate gear 9 is the pitch circle of the T side reel base gear 8 and the small diameter gear 111 of the T play intermediate gear 11. It is preferable for the arrangement of each part to be approximately the same as the sum of the diameters of D+E=6.8+8=14.8 -■ Therefore, ■
From formula and formula 0, D = 5.35, E~9.45.

Here, it is assumed that the module of each gear is 0.4.

■For expressions, ■For expressions, 12 8.8 9.6 β, = −x −x −= 4.06685.2 Here, if you select the case of formula ■ (D2, E2), T=4.63g-cra T-β, +=18.83·c+n.

・'-183-cm< T ・β2 Therefore, the diameter of the pitch circle of the small diameter gear 91 of the S side intermediate gear 9 is determined to be φ5.2, and the diameter E of the pitch circle of the S side reel stand gear 7 is determined to be φ9.6. be done.

Furthermore, the reduction ratio of the T-side gear train A is 2. ．． 59, the reduction ratio of the S-side gear train B is determined to be 4.06.

Thus, in the manner described above, the diameter of the pitch circle of each gear is set or determined from the required torque of each reel stand.

(G. Effects of the Invention) As is clear from the above description, the reel stand drive transmission mechanism of the cheap recorder of the present invention is suitable for a tape recorder that runs the tape in the Nljl Chishu mode and reverse playback mode using one capstan shaft. In the reel stand drive transmission mechanism, a supply side reel stand rotatably supported by the chassis, a take-up side reel stand rotatably supported at a position corresponding to the supply side reel stand of the chassis, and a drive unit. a gear, a supply side gear train that transmits the rotation of the drive gear to the supply side reel stand, a take-up side gear train that transmits the rotation of the drive gear to the take-up side reel stand, and a supply side gear of the drive gear. a clutch device that is provided between the drive gear and the drive source and that slips when a load is applied to the drive gear side. 41, and the ratio between the reduction ratio of the supply side gear train and the reduction ratio of the take-up side gear train is set to the torque required for winding the tape by the take-up side reel stand at the time of regeneration mode and reverse reproduction. It is characterized in that it is set to be approximately equal to the ratio of the torque required for winding up the tape by the supply side reel stand in the mode.

Therefore, the reel stand drive transmission mechanism of the tape recorder of the present invention does not require a clutch mechanism for each reel stand.
This makes it possible to simplify the structure, reduce the number of parts, prevent incorrect assembly of the clutch mechanism, and improve assembly workability.

Furthermore, since only one clutch mechanism is used, there is little chance of unstable power transmission due to aging, and this can be kept to a minimum.

In the above embodiment, the drive motor for driving each reel stand and the drive motor for moving the capstan shaft by 151A are common, but the present invention is not limited to this, and separate drive motors may be provided for each.

Furthermore, in the above embodiment, only one rocking gear is swung by the swiveling arm. It can also be applied to systems having two swing gears for one moving arm, and furthermore, the reduction ratio of each of the S-side gear train and the T-side gear train can be set to any gear in the gear train. It is up to the user to realize this by using the following method, and in the end, the reduction ratios of the S-side gear train and the T-side gear train may be made different.

Furthermore, the reel stand drive transmission mechanism of the cheap recorder of the present invention is of course applicable not only to digital audio tape recorders but also to video cheap recorders and audio tape recorders.

[Brief explanation of the drawing]

1 to 4 show an embodiment in which the reel stand drive transmission device 411ζ of the tape recorder of the present invention is applied to a digital audio tape recorder. FIG. 1 is a plan view of the main part, and FIG. 1 is an enlarged sectional view taken along the line II-II in FIG. 1, FIG. 3 is an enlarged sectional view taken along the line III-III in FIG. 1, and FIGS. 4 (A) and (B) are plan views showing each mode. , (A) shows the playback mode, (B) shows the reverse playback mode, and FIGS. 5 and 6 show an example of the reel table drive transmission mechanism of a conventional cheap coater. FIG. 6 is an enlarged sectional view taken along the line Vl--Vl in FIG. 5. Explanation of symbols 1: Tape recorder reel stand drive transmission mechanism;
2... Supply side reel stand, 3... Winding side reel stand, 4... Chassis, 13.15.18... Selection means, 20.21.22.23.24... Clutch machine 4m,
25... Drive gear, 28... Capstan shaft, 31... Tape, A... Winding side gear train, B...
Supply side gear train - rQ dimension! llJ&, -rO size PN~ smell~
2, 14,...: 9th - ni:! Plan view of main parts of kudzu and qu (conventional example) Fig. 5 Enlarged sectional view (vz-V1 track) (conventional example) Fig. 6

Claims (1)

[Claims] In a reel stand drive transmission mechanism for a tape recorder that runs a tape in playback mode and reverse playback mode using one capstan shaft, a supply side reel stand rotatably supported by the chassis corresponds to the supply side reel stand of the chassis. a take-up reel stand rotatably supported at a position, a drive gear, a supply gear train that transmits the rotation of the drive gear to the supply reel stand, and a drive gear on the take-up reel stand. a selection means for selecting meshing between a take-up side gear train transmitting the rotation of the drive gear and a supply side gear train or a take-up side gear train of the drive gear according to the rotational direction of the drive gear; a clutch mechanism provided between the drive gear and the clutch mechanism that slips when a load is applied to the drive gear side; A tape recorder characterized in that the ratio of the torque required for winding the tape by the take-up reel stand and the torque required for winding the tape by the supply reel stand in reverse playback mode is set to be approximately equal. reel stand drive transmission mechanism