JPH067465Y2 - Power transmission device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a power transmission device used in a PCM tape player, a video tape player, a cassette tape player, or the like.

[Technical Background and Prior Art] In a tape player, a pair of reel stands for driving a tape reel is provided. However, each reel stand is alternately driven by switching the power of one motor. It is common.

FIG. 7 is a plan view showing a power transmission device of this type of tape player. Reference numeral 1 in the drawing denotes a drive gear, which is rotationally driven in both forward and reverse directions by a motor (not shown). A swing arm 3 is supported by a shaft 2 of the drive gear 1, and an idle gear 5 is supported by a pin 4 at the tip of the swing arm 3. The idle gear 5 and the drive gear 1 are always meshed with each other. Reference numerals 6 and 7 are gears on the reel stand side. One gear 6 rotates together with a reel stand (not shown) on the take-up side, and the gear 7 rotates together with a reel stand (not shown) on the supply side.

In this power unit, the swing arm 3 and the idle gear 5 are
A rotational load applying mechanism using a spring, felt, or the like is provided between and, and the idle gear 5 is adapted to rotate with a predetermined load. Due to this load, when the drive gear 1 is driven by the motor in the counterclockwise direction, the rotational force of the drive gear 1 first causes the swing arm 3 to rotate in the counterclockwise direction, and the idle gear 5 causes the take-up reel stand. It is meshed with the side gear 6. Then, the rotational force of the drive gear 1 is transmitted to the gear 6 via the idle gear 5. vice versa,
When the drive gear 1 is driven in the clockwise direction, the swing arm 3 is driven in the clockwise direction, the idle gear 5 is meshed with the gear 7, and the gear 7 on the supply reel side is rotationally driven.

[Problems of Prior Art] In this power transmission device, the idle gear 5 is rotationally driven with a predetermined load on the swing arm 3 as described above. Therefore, the gear 6 on the reel stand side
When driving 7 or 7, the load causes a loss of power of the motor, which makes the operation of the entire mechanism heavy, and also causes a loss of power consumption.

The present invention focuses on the above-mentioned problems of the prior art, and allows the idle gear to completely mesh with the driven gear at the time of planetary movement without giving a rotational load to the idle gear. An object of the present invention is to provide a power transmission device capable of reducing and reliably switching power transmission.

[Means for Solving the Problems] A power transmission device according to the present invention is a drive gear driven by the power of a motor, and an idle gear that is engaged with the drive gear and is capable of planetary movement around the drive gear. The gear, a driven gear that is in a position meshing with the idle gear when the idle gear planetarily moves in the same direction as the rotation direction of the drive gear, and a predetermined load is applied, teeth of the idle gear, and the driven gear. And a switching member that does not apply a restraining force to the idle gear when the idle gear is brought into contact with the teeth of the idle gear and when the idle gear meshes with the driven gear by its own rotational force. It is characterized by.

[Operation] In the above means, the idle gear that is planetary moved with respect to the drive gear is moved in the direction of the driven gear by the switching member. At this time, the idle gear is not moved until it completely meshes with the driven gear. Move the idle gear to a position where the idle gear and the driven gear come into contact with each other. At this time, the planetary movement direction of the idle gear is the same as the rotation direction of the drive gear. Therefore, when the teeth of the drive gear and the teeth of the idle gear, which are applied with a predetermined load, come into contact with each other, the gears are engaged by the rotational force of the idle gear. At this point, the restraint of the switching member on the idle gear is released, but the idle gear continues to be urged by its own rotational force in the direction of maintaining the mesh with the drive gear.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a plan view showing a PCM (pulse code modulation) tape player using the power transmission device of the present invention, FIGS. 2 and 3 are sectional views showing the power transmission portion thereof, and FIGS. FIG. 6 is an explanatory diagram showing a power transmission operation.

Reference numeral 11 is a chassis of the PCM tape player. Reference numeral C is a tape cassette loaded on the chassis 11. The tape cassette C is equipped with a take-up reel Ra and a supply reel Rb, and a magnetic tape T is passed between both reels. In this PCM tape player, a magnetic tape T is pulled out from the tape cassette C by a tape pull-out member (not shown), and the magnetic tape T is loaded so as to be wound around the rotary drum 12 on the chassis 11. Rotating drum 1
2 is driven to rotate by a motor, and the rotary drum 12
A plurality of magnetic heads are mounted on the.

A capstan shaft 13 is provided on the chassis 11, and the capstan shaft 13 is rotationally driven by a motor Ma. The capstan shaft 13 is driven to rotate at a constant speed by a flywheel. A pinch roller 14 is opposed to the capstan shaft 13, and the magnetic tape T is nipped by the capstan shaft 13 and the pinch roller 14 moved to the position shown by the alternate long and short dash line during the play, and the power of the capstan shaft 13 is increased. Thus, the magnetic tape T is fed at a constant speed.

A pair of reel stands 15 and 16 are provided on the chassis 11. The take-up reel Ra in the tape cassette C is engaged with the reel stand 15 and the supply reel Rb is engaged with the reel stand 16. A reel gear 15a is integrally provided on the base of the reel stand 15, and the reel stand 1
A reel gear 16a is integrally provided on the base portion of No. 6.

A winding-side intermediate gear 17 is provided on the side of the winding-side reel gear 15a, and a supply-side intermediate gear 18 is provided on the side of the supply-side reel gear 16a. Intermediate gear 1
7 is rotatably supported on the chassis 11 by a shaft 19, and the intermediate gear 18 is by a shaft 20 on the chassis 1.
It is rotatably supported with respect to 1. As shown in FIG. 2, the intermediate gear 17 on the winding side is composed of a middle gear 17a, a large gear 17c located below it, and a small gear 17d located below it. There is. The middle gear 17a is always meshed with the reel gear 15a on the winding side. The large gear 17c is supported so as to rotate separately from the middle gear 17a. A felt 17b is interposed between the middle gear 17a and the large gear 17c,
Medium gear 17a and large gear 17c when no load is applied
Rotate together and under load both gears 17a and 17c
Has a slip structure. The small gear 17d is fixed to the boss of the middle gear 17a so that both gears 17a and 17d rotate together. The structure of the supply-side intermediate gear 18 is basically the same as that of the winding-side intermediate gear 17, and has a middle gear 18a, a large gear 18c, and a small gear 18d. Each gear 18a, 18c, 1
The relationship of 8d is the same as that of each gear 17a, 17c, 17d.

Further, reference numeral 21 is an idle drive gear. The idle drive gear 21 is rotatably supported on the chassis 11 by a shaft 23. As shown in FIG. 2, a pulley 21a is integrally formed on the lower portion of the idle drive gear 21, and the pulley 21a is connected to a drive pulley 13a integral with the capstan shaft 13 by a belt 22. The idle drive gear 2 is driven by the power of the motor Ma.
1 is rotationally driven together with the capstan shaft 13. A base of a swing arm 24 is axially slidably supported on a shaft 23 on which the idle drive gear 21 is supported. The base of this swing arm 24 is
As shown in the figure, it is biased upward by a spring 25. FIG. 3 shows a state in which the swing arm 24 is lifted up by the elastic force of the spring 25, and FIG. 2 shows a state in which the swing arm 24 is pushed down against the elastic force of the spring 25. .

A shaft 26 is fixed to the tip of the swing arm 24.
An idle gear 27 is rotatably supported on the shaft 6. The idle gear 27 is composed of a small gear 27a and a large gear 27b. As shown in FIG. 2, the large gear 27b always meshes with the idle drive gear 21. No rotational load applying mechanism is provided between the idle gear 27 and the swing arm 24, and the idle gear 27 is supported so as to rotate on the shaft 26 with a minimum load. Also,
A switching pin 28 directed upward is fixed to the tip of the swing arm 24.

Two switching levers 31 and 35 are provided on the chassis 11. The first switching lever 31 is the chassis 11
It is slidably supported above (a)-(b). Similarly, the second switching lever 35 is slidably supported in the (c)-(d) directions. A groove 31a is formed in the right end portion of the first switching lever 31 in the drawing, and the drive pin 32 is inserted into the groove 31a. The drive pin 32 is fixed to the switching gear 33. A motor Mb is provided on the chassis 11, and the power of the motor Mb is transmitted to the switching gear 33 via the gear group 34. That is, the first switching lever 31 is connected to the motor Mb.
It is driven in the directions (a)-(b) by the power of.
A switching hole 31b is formed in the center of the first switching lever 31, and a switching pin 28 provided at the tip of the swing arm 24 is inserted into the switching hole 31b. The switching hole 31b has a width dimension larger than the diameter of the switching pin 28.

A groove 35a is formed at the right end of the second switching lever 35 in the figure.
Is formed, and the drive pin 36 is inserted into the groove 35a. The drive pin 36 is fixed to an L-shaped drive lever 37. The chassis 11 is provided with a motor (not shown) different from the above-mentioned two motors Ma and Mb, and the drive lever 3 is driven by the power of this motor.
7 is driven. The motor (not shown) switches the pinch roller 14, and the power of the motor drives a lever or the like, which causes the pinch roller 14 to move between the position indicated by the solid line and the position indicated by the alternate long and short dash line in FIG. It is designed to switch. That is, the second switching lever 35 is used for the pinch roller 14
It is driven in the (c)-(d) direction in conjunction with the switching operation of. The driving piece 3 is provided at the center of the second switching lever 35.
5b is integrally provided. As shown in FIG. 2, the driving piece 35b is bent upward, and the driving piece 35b is bent.
When b reaches above the base of the swing arm 24, the swing piece 24 is pushed down by the drive piece 35b.

Next, the operation of the PCM tape player having the above configuration will be described.

The operation of the PCM tape player is composed of an unloading state, a stop-up state after tape loading, an FF operation (tape fast forward), a REW operation (tape rewinding), a normal play mode and a reverse play mode. FIG. 1 shows a stopped state after tape loading. 2 and 4 show FF operation, and FIG. 3 shows normal play.

A drawer member (not shown) in the unloading state
Is returned to the vicinity of the reel stands 15 and 16, and the tape cassette C is loaded on the chassis 11 in this state. When the tape cassette C is loaded, a loading mechanism (not shown) is started, and the magnetic tape T is pulled out from the inside of the tape cassette C to the upper side in the drawing of FIG. The magnetic tape T is wound around the lower half of the rotary drum 12 in the drawing by a pull-out member. Further, the magnetic tape T is guided by the respective guide pins 41a, 41b, 41c, and passes near the capstan shaft 13. A servo pin 42 is provided between the guide pins 41a and 41c on the left side of the drawing. The servo pin 42 adjusts the tension of the magnetic tape T.

FIG. 1 shows a stopped state after tape loading. At this time, the switching gear 33 is in the neutral position by the power of the motor Mb located in the lower right part of the chassis 11,
That is, the drive pin 32 is stopped with the drive pin 32 positioned in the center. Therefore, the first switching lever 31 is at the neutral position, and the switching pin 31 is positioned at the center by the switching hole 31b at the center of the switching lever 31. Therefore, the idle gear 27 supported by the swing arm 24 is
The left and right intermediate gears 17 and 18 are not in mesh with each other. Further, the L-shaped drive lever 37 is stopped in a state of being rotated counterclockwise by the power of a motor (not shown), and the second switching lever 35 is moved in the direction (c) by the drive pin 36. Has been made. In this state, the driving piece 35b at the center of the second switching lever 35 is located above the base of the swing arm 24, and as shown in FIG. It has been pushed down against the opposition pressure of. Also, the L-shaped swing lever 37 is the first
As shown in the figure, when it is rotated counterclockwise,
The pinch roller 14 is separated from the capstan shaft 13 by another switching lever connected to the drive lever 37.

Next, the FF operation will be described.

This FF operation is an operation mode when the magnetic tape T is fast-forwarded or when the recorded information is cued in the fast-forward state.

When switching to this FF operation, as shown in FIG. 1, the pinch roller 14 is separated from the capstan shaft 13 and the second switching lever 35 is moved in the direction (c) while the motor is being operated. Start Mb and rotate the switching gear 33 to move the first switching lever 31 to (a) as shown in FIG.
Move in the direction. At the same time, the motor Ma is started at high speed counterclockwise. The power of this motor Mb is belt 2
2 is transmitted to the pulley 21a shown in FIG. 2, and the idle drive gear 21 is rotationally driven counterclockwise. The idle gear 27, which is always meshed with the idle drive gear 21, is driven clockwise. As described above, since the rotational load applying mechanism is not provided between the idle gear 27 and the swing arm 24, the idle drive gear 2
A rotation of 1 does not generate a force for rotating the swing arm 24. However, as described above, the first switching lever 3
Since 1 is moving in the (a) direction, this switching lever 3
The first switching hole 31b pushes the switching pin 28 in the (a) direction, and the swing arm 24 is driven counterclockwise. At this time, the drive piece 35b of the second switching lever 35
Since the swing arm 24 is pushed down by the large gear 27b of the idle gear 27 provided on the swing arm 24 as shown in the second part, the intermediate gear 17 on the take-up side is
Of the idle gear 27 by the counterclockwise rotation of the swing arm 24.
b approaches the small gear 17d of the intermediate gear 17. here,
When the switching pin 28 is pushed by the switching hole 31b of the first switching gear 31 to completely engage the large gear 27b and the small gear 17d, the moving position of the switching lever 31 and the dimensional accuracy of the switching hole 31b are high. Must be accurate. However, in the embodiment of the present invention, these moving positions and dimensional accuracy are relatively rough, and the switching lever 31
The oscillating arm 24 is moved to a position where the tooth tips of the large gear 27b and the small gear 17d come into contact with each other, and the switching lever 31 is stopped at that position. After that, when the large gear 27b of the idle gear 27 continues to rotate, as shown in FIG. 6, the tooth tip of the large gear 27b presses the tooth tip of the small gear 17d of the intermediate gear 17 by the force α. Since a load such as tape tension is applied to the intermediate gear 17 via the reel gear 15a, the large gear 27b receives a force β in the direction opposite to the rotation thereof due to the reaction of the tooth tip force α. The swinging arm 24 is automatically rotated counterclockwise by this force β, and the two gears 27b and 1
7d is in a completely meshed state. When the swing arm 24 rotates because the gears automatically mesh with each other, the switching pin 28 moves in the β direction within a margin within the switching hole 31b of the switching lever 31. Therefore, thereafter, the rotation of the idle gear 27 is transmitted to the small gear 17d (see FIG. 5), and the reel stand 15 is driven clockwise through the middle gear 17a of the intermediate gear 17. Then, the magnetic tape T in the tape cassette C is fast-forwarded.

Next, the REW operation will be described.

This REW operation is a mode in which the magnetic tape T is rewound at high speed, or the recorded information is cueed in this rewound state.

The switching to the REW operation is performed by the motor Mb while the pinch roller 14 is separated from the capstan shaft 13 and the second switching lever 35 is moved in the (c) direction as in the FF operation. This is performed by moving the lever 31 in the (b) direction. At this time, contrary to the case of the FF operation, the switching pin 28 is pushed in the (b) direction by the switching hole 31b of the switching lever 31, so that the large gear 27b of the idle gear 27 moves the small gear 18d of the intermediate gear 18 on the supply side. Be approached. When the motor Ma is driven in the clockwise direction at a high speed and the idle gear 27 is driven in the counterclockwise direction, the large gear 2 is driven as in the FF operation.
7b and the small gear 18d are automatically meshed with each other by the repulsive force between the tooth tips. Then, the supply-side reel stand 16 is driven counterclockwise, and the magnetic tape T is rewound at high speed.

Next, normal play will be described.

When switching to the normal play mode, the L-shaped drive lever 37 is rotated clockwise by a motor or the like, and the second switching lever 35 is moved by the drive pin 36.
Move in direction (d). As a result, the drive piece 35b at the center of the switching lever 35 is disengaged from above the base of the swing arm 24, and the swing arm 24 is lifted upward by the force of the spring 25, as shown in FIG. As a result, the idle gear 27 supported by the swing arm 24
The small gear 27a of the two is opposed to the large gear 17c of the intermediate gear 17. In addition, the L-shaped drive lever 37
Operation causes the pinch roller 14 to move the capstan shaft 13
Is pressed against. The first switching lever 31 is moved in the (a) direction, the switching pin 28 is pushed in the same direction, and the tip of the small gear 27a comes into contact with the tip of the large gear 17c. Then, the motor Ma is driven counterclockwise at a low speed. This power is transmitted to the idle drive gear 21 by the belt 22, and the idle gear 27 is driven clockwise at a low speed. Also in this case, due to the pressure between the tooth tips of the small gear 27a of the idle gear 27 and the large gear 17c of the intermediate gear 17, both gears 27a and 17c are automatically brought into a completely meshed state. Therefore, the intermediate gear 17
The reel base 15 on the take-up side is rotationally driven in the clockwise direction via, and the magnetic tape T is taken up at a low speed. During play, the capstan shaft 13 and the pinch roller 14, which rotate at a constant speed by the flywheel, sandwich the magnetic tape T and run the magnetic tape T at a constant speed.
The speed difference between the reel stand 15 and the capstan shaft 13 at this time is absorbed by the large gear 17c of the intermediate gear 17 slipping between the felts 17b. While the magnetic tape T is running, the rotary drum 12 is rotationally driven, and information is recorded / reproduced by the magnetic head mounted on the rotary drum 12.

Next, the reverse play will be described.

This reverse play is a mode that can be switched when the magnetic tape T is run in the reverse direction in the same state as the normal play mode and the recording information is cued at a low speed.

To switch to this mode, press the pinch roller 14 against the capstan shaft 13 in the same manner as in normal play,
The first switching lever 31 is moved in the direction (b) while the second switching lever 35 is moved in the direction (d). Since the swing arm 24 is lifted by the spring 25 as in the normal play mode, the small gear 27a of the idle gear 27 is moved by the movement of the switching lever 31 in the direction (b) to the large gear 18c of the intermediate gear 18 on the supply side. Approach. In addition, the motor Ma
Is driven clockwise at a constant speed. Therefore, the idle gear 27 is driven counterclockwise, and both gears 27a and 1
8c is automatically engaged by the pressure of the tooth tip.
As a result, the reel table 16 on the supply side is driven counterclockwise, and the timing tape T runs in the rewinding direction at a constant speed. The running speed of the magnetic tape T at this time is also determined by the rotation speed of the capstan shaft 13 as in the normal play.

In the illustrated embodiment, the switching lever 31 for moving the swing arm 24 slides linearly, but this switching lever rotates, and this rotation operation is performed. Alternatively, the switching pin 28 may be moved left and right. Further, the switching lever 31 may be driven by a solenoid instead of the motor.

The present invention can also be implemented in video tape players and cassette tape players.

[Advantage of the Invention] As described above, according to the present invention, the idle gear is moved to the position where the teeth of the driven gear are given a predetermined load, and the idle gear is rotated by the rotational force of the idle gear. The driven gear is brought into a meshed state, and in this meshed state, the restraining force in the driven gear direction is not applied to the idle gear. In this way, the idle gear is brought into mesh with the driven gear by its own rotational force, so that it is not necessary to apply a rotational load for planetary movement to the idle gear as in the conventional power transmission device. Therefore, unnecessary load does not act on the power transmission system, and the rotational load of the motor can be reduced.

Further, the switching member moves the idle gear to a position where the teeth of the idle gear and the teeth of the driven gear come into contact with each other, and does not apply a restraining force to the idle gear thereafter. A relatively rough size until the teeth of the gear hit is sufficient, and the mechanical parts and structure can be simplified.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention. FIG. 1 is a plan view showing a PCM tape player using the power transmission device of the present invention, and FIGS. 2 and 3 are first views. FIG. 3 is a cross-sectional view showing the power transmission device shown in FIG. 2, FIG. 2 showing an FF mode, and FIG. 3 showing a normal play mode. FIG. 4 is a plan view showing a part of the power transmission device in the FF mode,
FIG. 5 is a plan view showing the gear meshing state, FIG. 6 is an enlarged view showing the tooth tips of the gear, and FIG. 7 is an explanatory view showing the operation of the conventional power transmission device of the tape player. 11 ... Chassis, 12 ... Rotating drum, 13 ... Capstan shaft, 14 ... Pinch roller, 15 ... Take-up reel stand, 15a ... Take-up reel gear, 16 ... Supply reel stand, 16a ...... Supply reel gear, 17 ……
Intermediate gear on winding side, 18 ... Intermediate gear on supply side, 21
... idle drive gear, 23 ... idle drive gear shaft, 24 ... swing arm, 28 ... switching pin, 27
... idle gear, 31 ... switching lever (switching member), 31b ... switching hole, Ma ... motor for rotating capstan shaft and idle gear, Mb ... motor for switching lever, C ... tape cassette, T ……Magnetic tape.

Claims (1)

[Scope of utility model registration request] 1. A drive gear driven by the power of a motor, an idle gear provided so as to mesh with the drive gear to allow planetary movement around the drive gear, and the idle gear has the same rotational direction as the drive gear. The idle gear is moved to a position where the idle gear and the driven gear, which is in a position meshing with the idle gear and is applied with a predetermined load when the planet moves in the direction, come into contact with the idle gear teeth and the idle gear teeth. A power transmission device comprising: a switching member that does not apply a restraining force to the idle gear when the idle gear is brought into mesh with the driven gear due to its own rotational force.