JPH0376548B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a cassette deck, and more particularly to a starting mechanism for an eject mechanism in a cassette deck.

BACKGROUND ART In recent years, cassette decks have been becoming more and more compact.In particular, when it comes to automotive cassette decks, there is a limit to the space in which the cassette decks can be accommodated, so there is a strong demand for smaller and thinner cassette decks. be.

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide a starting mechanism for an eject mechanism that can simplify the mechanism and contribute to making the cassette deck smaller and thinner, and also ensure reliable operation of the mechanism.

Composition of the Invention The eject mechanism starting mechanism according to the present invention is a starting mechanism for the eject mechanism that is to be automatically operated in response to the stoppage of rotation of the reel unit in the cassette deck, and is a starting mechanism for the eject mechanism that is driven by the reel unit drive motor 50 as a power source. A cam mechanism 82, a power lever 85 which is provided to be reciprocally movable and controls activation of the eject mechanism on its outward path, and a power lever 85 which is pivotally supported by the power lever and engages with the rotary cam mechanism when the rotation of the reel unit is stopped. a sensing arm 84 that causes the power lever to move forward;
and a biasing means 88 for returning the power lever when the engagement between the rotary cam mechanism and the sensing arm is released, and a reset arm provided to be engageable with the cassette half 5 loaded in the playing position. 89, the reset arm is characterized in that when the cassette half is ejected, the reset arm swings the sensing arm to forcibly release the engagement with the rotating cam mechanism.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

Note that the features of the present invention are particularly described in the first section.
and FIG. 2, and FIGS. 13 and 14.

1 and 2 are a schematic plan view and a schematic side view showing a cassette deck according to the present invention. In FIGS. 1 and 2, a cassette push lever 2 is engaged with the side frame 1 so as to be slidable in the left-right direction in the figures, and a first arm 3 is pivotably supported around a shaft 3a. (See Figure 3). The first arm 3 is engaged with a pin 2a installed in the cassette push lever 2 through a long hole 3b formed at its tip, and when loading the cassette half 15, the cassette half 15 is inserted into the cassette half 15 as shown in FIG. When the push lever 2 is moved to the left in the figure, it swings counterclockwise. The tip of the cassette push lever 2 is bent into a substantially L shape so that the rear end of the inserted cassette half 15 can come into contact with it. A first lever 4 is swingably supported on the first arm 3, and the first lever 4 moves to the left in the figure, that is, in the cassette insertion direction, due to the swing of the first arm 3. , the side frame 1 is biased toward the right in the figure.

The second lever 6 is slidably engaged with the side frame 1 in the left-right direction in the figure, and the fourth
As shown in the figure, when the first lever 4 moves to the left, the first lever 4
and move in the cassette insertion direction (to the left in the figure). A third lever 8 is slidably attached to the second lever 6 and is biased by a spring 9 in the cassette insertion direction.
As is clear from FIG. 4, the third lever 8 engages at its tip 8a with one end 11a of a swinging arm 11 that is swingably supported by a shaft 10 with respect to the side frame 1, and is spring-loaded. The swinging arm 11 is urged clockwise by the urging force 9.

A regulation arm 12 is swingably supported on the side frame 1 by a shaft 7a, and a lock arm 13 is swingably supported on the regulation arm 12 by a shaft 7b, as shown in FIG. Axis 7a
The regulating arm 12 is biased counterclockwise and the lock arm 13 is biased clockwise by a spring 14 provided around the side frame 1 and having one end engaged with the side frame 1 and the other end engaged with the lock arm 13, respectively. In this way, by adopting a configuration in which both the regulation arm 12 and the lock arm 13 are attached to the side frame 1 only by rotating them, the load loss accompanying the operation of both arms is reduced, and the spring The urging force of 14 can be small,
Not only the coil spring itself but also the reaction force receiving part provided on the side frame 1 to receive the reaction force can be made small and lightweight with weak strength, making it possible to downsize the cassette deck. Contributes to thinning. The lower end 13a of the lock arm 13 engages with the protrusion 6b of the second lever 6, and when the cassette half 15 is loaded, the protrusion 6b of the second lever 6 moves in the left direction in the figure in conjunction with the cassette push lever 2. When the cassette half 15 is fully inserted, the bent portion 2b of the front end of the cassette push lever 2 swings clockwise due to the biasing force of the spring 14, as shown in FIG. is locked with its hook portion 13b.

The cassette holder 16 is swingably supported on the side frame 1, and the tip elongated hole 1 of the swinging arm 11 is connected to the end of the swinging arm 11 via a pin 16a at the intermediate portion thereof.
1b. As a result, the cassette holder 16 is biased clockwise in the figure by the spring 9 via the swing arm 11 and the third lever 8, but as is clear from FIG. By engaging with the portion 12a, its swinging is restricted. And cassette half 15
is inserted completely all the way, and the cassette push lever 2
When the bent portion 2b is locked by the lock arm 13, the regulating arm 12 is slightly swung clockwise via the lock arm 13 by the biasing forces of the springs 5 and 9 acting on the cassette push lever 2. As a result, as shown in FIG. 5, the restriction on the swinging of the cassette holder 16 is released. As a result, the cassette holder 16 is swung clockwise by the biasing force acting on the swiveling arm 11, and the cassette half 15, which has been fully inserted, is pushed down to the playing position.

28 is an FF lever that commands fast forwarding (FF) of the tape, and 29 is a REW lever that commands rewinding (REW) of the tape.
are made up of longitudinal plate-like members that are slidably stacked on top of each other and extend from the front (right side in the figure) to the rear (left side in the figure) of the device. Further, a longitudinal plate-shaped cam lever 30 is slidably superimposed on the levers 28 and 29, and these three levers 2
8, 29, 30 are elongated holes 28 formed at both ends.
a, 29a, 30a and 28b, 29b, 30b
, the shafts 31a and 3 fixed to the chassis 17
1b in a slidable manner. cam lever 30
The width of the elongated hole 30b of the levers 28, 29 is approximately equal to the diameter of the shaft 31b, whereas the elongated holes 28b, 29b of the levers 28, 29
As shown in FIG. 22a, the width of the levers 28 and 29 is larger than the diameter of the shaft 31b to the extent that a predetermined distance t is left between the levers 28 and the peripheral wall of the shaft 31b on the left and right sides. As shown in FIGS. 22a and 22b, it can swing in the width direction of the long holes 28b, 29b and in the axial direction of the shaft 31b, centering on the shaft 31a engaged in the long holes 28a, 29a at the tip. As a result, each operation button 32, 33 of the lever 28, 29
When attaching the button to the opening 34a of the grill 34, even if a relative positional shift with respect to the grill 34 of the main body of the device occurs, each operation button 32, 33 can be reliably positioned with respect to the opening 34a of the grill 34. become. Although only the FF lever 28 is shown in FIGS. 22a and 22b, the REW lever 29
has a similar structure. The FF lever 28 and the REW lever 29 each have a bent portion 35,
36 are formed, and these bent portions 35, 36
are in contact with the protrusions 37a and 37b at both ends of the second arm 37. The second arm 37 is attached to a fixed pin 38 of the cam lever 30. Further, a spring 39 is stretched between the cam lever 30 and the shaft 31b. Here, when the FF lever 28 and the REW lever 29 are pressed alone, they act as operating levers that command FF and REW, but when both are pressed at the same time, they act as operating levers that command EJECT. do. That is, the amount of movement of the pin 38 when both levers 28 and 29 are pressed simultaneously is greater than the amount of movement when each lever is pressed individually, and the eject operation is performed based on this difference in movement amount.
Note that when the FF lever 28 and the REW lever 29 are operated individually, they are locked by a locking mechanism to be described later, but when both levers 28 and 29 are pressed simultaneously, they are not locked.

The amount of movement of the pin 38 directly becomes the amount of movement of the cam lever 30, and the cam lever 30 is the same as the amount of movement of the FF lever 28.
When the claw 30c moves a predetermined amount to the left in the figure in response to an eject operation by simultaneously pressing the REW lever 29 and the REW lever 29, the claw 30c comes into contact with one end of the swingable third arm 40 and swings it counterclockwise. . As a result, the other end of the third arm 40 is connected to one end 43a of the lock release lever 43 which is swingable via the selection lever 42 which is biased upward in the figure by the spring 41.
Press and rock it.

When the lock release lever 43 swings, the other end 43b moves upward in FIG. 8, and the tip of the first lever 4 is brought to a position where it can be engaged with the other end 43b by loading the cassette. By pushing up the part, the engagement between the pawl 4a of the first lever 4 and the protrusion 6a of the second lever 6 is released. As a result, the second lever 6 moves to the right, and as shown in FIG.
1a causes the swing arm 11 to swing counterclockwise. This causes the cassette holder 16 to lift up the cassette half 15. Also, when the cassette half 15 is raised, the lock arm 1
3 swings counterclockwise as its lower end 13a is pressed by the protrusion 6b of the second lever 6 moving rightward, and as shown in FIG. At this point, the bent portion 2b of the cassette push lever 2 is unlocked. Therefore, the cassette push lever 2 moves to the right and ejects the cassette half 15. The force required for lifting and ejecting the cassette half 15 during this ejection is provided by the springs 5 and 9, which are stretched during loading.

FIG. 10 shows a reel unit drive mechanism in a cassette deck according to the present invention. 1st
In FIG. 0, a belt 54 is installed between a pulley 52 connected to a rotating shaft 51 of a motor 50 and a flywheel 53. Note that the central axis of the flywheel 53 is the capstan 55. A gear 56 is provided coaxially and integrally with the flywheel 53. The gear 56 includes, as shown in FIG.
An idler gear 59 rotatably supported by an idler arm 57 which can swing around a capstan 55 with respect to the chassis 17 and is biased counterclockwise by a spring 58 is engaged with the idler gear 59. When in the play state, the reel drive gear 61 can mesh with a reel drive gear 61 that is integrally formed with the take-up reel unit 60. The reel unit 60 is provided with a sensing release arm 62 that engages with a reel drive gear 61 via a predetermined friction member.

The supply reel unit 63 is provided with, for example, two locking claws 64a and 64b. The ratchet arm 66, which is swingably supported by a pin 65 implanted in the chassis 17, is biased clockwise in the figure by a spring 67 so that one end 66a thereof can engage with the locking pawls 64a and 64b. The ratchet mechanism is provided in the ratchet mechanism. When entering the play state, the other end 66b of the ratchet arm 66 is pressed by the protrusion 68a of the head stand 68 as the head stand 68 moves to the forward position, and is rotated counterclockwise to activate the ratchet mechanism. It is starting to be released.

As is clear from FIG. 12, the limiter gear 69 is rotatably supported on a limiter arm 71 which is swingably supported on the chassis 17 by a shaft 70, and when the head stand 68 is in the retracted position, the limiter arm 71 is rotated. The flywheel gear 53 is constantly biased by a spring 72 that biases clockwise in the figure.
It is meshed with. At this time, the pin 57 of the idler arm 57 is inserted into the square hole stepped portion 68c of the head stand 68.
a is engaged and the idler arm 57 swings clockwise in the figure, so the idler gear 59 does not mesh with the reel drive gear 61. When the head stand 68 moves to the forward position and enters the play state, the bush 68b of the head stand 68 swings the limiter arm 71 clockwise in the figure to release the engagement between the flywheel gear 53 and the limiter gear 69. On the other hand, since the engagement between the square hole stepped portion 68c of the head stand 68 and the pin 57a of the idler arm 57 is released, the idler gear 59 meshes with the reel drive gear 61 and drives the reel unit 60 at a constant speed.

An idler gear 74 rotatably supported by a shaft 73 meshes with the limiter gear 69 . As is clear from FIG. 11, the shaft 73 of the idler gear 74 is fixed to the idler lever 75 and is configured to be linearly movable along a long hole 76 bored in the chassis 17. Since the idler lever 75 is biased upward in the drawing by the spring 77, the idler gear 74 normally drives the reel drive gear 61 on the winding side via the FF gear 78 (FF). On the other hand, in connection with the REW operation described later, the switching lever 79 moves the idler lever 75 downward against the spring 77 as shown in FIG. 11, so that the idler gear 74 meshes with the reel drive gear 80 on the supply side. (REW).

Referring again to FIG. 10, a cam gear 81 is rotatably supported on the chassis 17 by a shaft 82, and the driving torque of the motor 50 is transmitted to the cam gear 81 via three gears 83a, 83b, and 83c. be done. As shown in FIG. 13, a sensing arm 84 having a claw 84a that can be appropriately engaged with the cam 81a of the cam gear 81 is pivotally supported by a shaft 86 with respect to the sensing power lever 85. In such a configuration, the motor 50
Accordingly, the power applied to the cam gear 81 and transmitted to the sensing arm 84 is directly transmitted to the sensing power lever 85. Therefore, no special mechanism for force transmission is required, and the entire starting mechanism is simple, contributing to miniaturization and thinning of the cassette deck. On the other hand, a T-shaped arm 87 is swingably supported coaxially with the cam gear 81, and this T-shaped arm 87 is engaged with the pin 62a of the sensing release arm 62 mentioned above at the lower end elongated hole 87a. reel unit 60
is rotating, the sensing release arm 62 swings to the right or left depending on the direction of rotation, and the sensing arm 84 swings counterclockwise in FIG. 8
1 from a position where it can engage with the cam 81a. When the rotation of the reel unit 60 stops, the sensing release arm 62 does not swing, so the claw 84a of the sensing arm 84 is brought to a position where it can engage with the cam 81a by the action of the outer peripheral inner wall of the cam gear 81. The rotational torque causes the sensing arm 84 to move to the left in FIG. Since the sensing arm 84 and the sensing power lever 85 are coupled via the shaft 86, the sensing power lever 85 also moves together with the sensing arm 84 against the elastic force of the spring 88. Claw 84a of sensing arm 84
When the cam gear 81 is disengaged from the cam 81a, the restoring force of the spring 88 returns it to its original position.

Further, as shown in FIG. 14, a reset arm 89 is swingably provided coaxially with the T-shaped arm 87 and urged clockwise in the figure by a spring 90. An inclined portion 89a at one end of the reset arm 89 normally protrudes toward the loading side of the cassette half as shown in FIG. When the cassette half is oscillated and the cassette half is ejected, it oscillates clockwise in FIG. 14 due to the urging force of the spring 90, and the sensing arm 84 is oscillated counterclockwise in the drawing at the other end 89b. According to this, the claw 84a of the sensing arm 84 and the cam 81 of the cam gear 81
Even if an auto-eject operation, which will be described later, is completed and the motor 50 is stopped immediately before it is disengaged from the sensing arm 84, the claw 84a of the sensing arm 84 and the cam 81a of the cam gear 81 are reset by the action of the reset arm 89. Since the engagement with the reel unit can be reliably released, the eject operation can be performed reliably the next time the reel unit is stopped.

In FIG. 1, the selection lever 42 and the sensing power lever 85 are arranged in parallel with each other and are configured to be able to slide downward in the figure either individually or together. Further, the selection lever 42 is connected to a lock release lever 43 which is the first stage component of the eject mechanism.
The one end 43a is used as a point of action, and the one end 43a is used as a swinging fulcrum to swing between an engaged position and a non-engaged position with the sensing power lever 85 against the biasing force of the spring 41. There is a concave portion 42a and a bent portion 8 of the sensing power lever 85.
It is adapted to selectively engage and disengage from 5a.
In this way, since the swing fulcrum of the sorting lever 42 is set as the point of action for the lock release lever 43, which is the first stage component of the eject mechanism, one pin serves both as the swing fulcrum and as the point of action. This reduces the number of fulcrum pins, reduces the number of parts, and simplifies the entire mechanism, contributing to smaller and thinner cassette decks. In the play state in which the head stand 68 is in the forward position, as shown in FIG. When the sensing power lever 85 moves downward in FIG. 1 due to the sensing operation described in FIG. 13, the sorting lever 42 also moves together, thereby causing the lock release lever 43 to move in the same way as during the manual reset operation. Since the tape is driven by the selection lever 42, an eject operation is automatically performed at the end of the tape.

On the other hand, as shown in Figure 16, FF or REW
Sometimes the FF lever 28 or the REW lever 29
presses the rising part 42b of the sorting lever 42 with its tip to swing the sorting lever 42, and the concave part 42a of the sorting lever 42 and the sensing power lever 85
Since the engagement with the bent portion 85a has been released, even if the sensing power lever 85 moves due to the sensing operation, the selection lever 42 does not move and the ejecting operation is not performed. As shown in FIG. 17, a lock arm 93 is provided which is swingably supported by a shaft 31a and urged clockwise by a spring 92. As shown in the figure or FIG. 21, the FF lever 28 or
The REW lever 29 is locked in a pressed state, and when the sensing power lever 85 moves, its falling portion 85b presses the falling portion 93b of the lock arm 93 to move the lock arm 93 to the first position.
6, the FF lever 28 or REW lever 29 is unlocked.

When the head stand 68 is in the retracted position, the pinch roller unit 91 rotates about the shaft 31a in the counterclockwise direction in the figure, as shown in FIG. Since the falling portion 42c is pressed to swing the sorting lever 42, no eject operation is performed as in the case of FF or REW. At this time, when only the sensing power lever 85 moves, as shown in FIG. The lock arm 95, which locks the head stand 68 in the retracted position by engaging with the bent portion 68d of the stand 68, is moved by the falling portion 85b of the sensing power lever 85 as shown in FIG. Since it is swung counterclockwise, the head stand 68 is unlocked.

In FIG. 18, the head stand 68 is engaged with the pin 91b of the pinch roller unit 91 through the hole 68e, and when the head stand 68 is unlocked, there is a space between the pinch roller unit 91 and the chassis 17. A forward force is applied to the head stand 68 by the tensioned spring 96. The head stand 68 also engages with an arm 98 swingably supported on the chassis 17 via a shaft 97 at its front end rising portion 68f, urging the arm 98 clockwise in the figure. A forward force is also applied by the spring 99 to move in the direction of the arrow. Head stand 68
At the same time as the pinch roller unit 91 moves forward, the pinch roller unit 91 swings clockwise in the figure, and the pinch roller 100 moves forward. When ejecting, as shown in FIG. 9, the arm 98 is rotated counterclockwise by the lever 101 which returns due to the biasing force of the spring 102, so the head stand 68 retreats and the pinch roller 1
00 also retreats at the same time, returns to its current state, and is locked in the retreated position by the lock arm 95.

Next, fast forward (FF) and rewind (REW) operations will be explained.

When the FF lever 28 is pressed as shown in FIG. 20 while a cassette is loaded and the tape deck is in play mode, the protrusion 28a of the FF lever 28 is pressed.
engages with the lock pin 93a of the lock arm 93, and the FF lever 28 is locked in the operating position.The cam part 28b is fixed to the head stand 68 and presses the head stand pin 102 in the right direction in the figure, so that the head stand 68 moves back a little. Then, the pinch roller 100 retreats and the pressure contact with the capstan 55 is released, and at the same time the head 25 comes into light contact with the tape. At this time, as shown in FIG. 12, the pin 57a of the idler arm 57 is pushed down by the square hole stepped portion 68c of the head stand 68, and the idler arm 57 rotates clockwise in the figure to drive the reel. Gear 61 and idler gear 59
The mesh is released. On the other hand, at the same time, the engagement between the head stand bush 68b and the limiter arm 71 is released, so the limiter arm 71 swings clockwise in the figure due to the biasing force of the spring 72, and the limiter gear 69 meshes with the flywheel gear 53. The high-speed rotational torque is generated by the flywheel gear 53.
From limiter gear 69, idler gear 74 and
It is supplied to the reel drive gear 61 via the FF gear 78. In this way, the tape deck performs a fast forward motion.

To stop the fast forward operation, lightly press the REW lever 29 from the state shown in Fig. 19.
Since the protrusion 29a of the lever 29 slightly presses the lock pin 93a in the right direction in the figure, the FF lever 28
The engagement between the protrusion 28a and the lock pin 93a is disengaged, the FF lever 28 is restored by the elastic force of the spring 39, and the cassette deck returns to its original playing state.

Furthermore, when a tape end state occurs during fast-forwarding, the reel unit rotation stop sensing mechanism (see FIG. 13) is activated, and as explained in FIG. 18, the sensing power lever 85 is moved. As a result, the FF lever 28 is unlocked and the head stand 68 moves forward to return to the play state.

Next, when performing a rewind operation, press the REW lever 29 strongly.
As shown in FIG. 21, the REW lever 29 is locked in the operating position by engaging the protrusion 29a with the locking pin 93a. Then, FF
As before, the head stand pin 102 is pushed in the direction of the arrow by the cam portion 29b, so that the head stand 68
moves backward, and the idler gear 59 and reel drive gear 61
The mesh is released. At the same time, as shown in FIG. 11, the second arm 37 swings clockwise in the figure around the pin 38 in connection with the pressing operation of the REW lever 29, thereby causing the second arm 37 to attach to the pin 79a.
The switching lever 79 engaged through the switch moves in the direction of the arrow in the figure and moves the idler lever 79 downward in the figure, so that the idler gear 74 moves linearly along the elongated hole 76 and switches to the reel drive gear 80. , high-speed rotating torque is supplied from the flywheel 53 to the drive reel drive gear 80 via the limiter gear 69 and the idler gear 74, and a rewinding operation is performed.

Effects of the Invention As detailed above, in the starting mechanism of the eject mechanism according to the present invention, the sensing arm 84
is pivotally supported on a power lever 85. In such a configuration, the motor 50 rotates the rotating cam mechanism 8.
1 and transmitted to the sensing arm 84 is directly transmitted to the power lever 85. Therefore, there is no need for a force transmission mechanism, and the entire starting mechanism becomes simple, making the cassette deck more compact.
This contributes to making it thinner.

On the other hand, in the present invention, a new problem arises due to the adoption of the above-mentioned configuration.
In the event that the motor 50 stops before the motor 50 is disengaged from the motor 50, the engagement state is maintained and the return operation of the power lever 85 by the biasing means 88 is no longer performed. In order to solve this problem, the reset arm 89 is provided.

That is, when the cassette half is ejected, the sensing arm is forcibly swung by the reset arm to reliably release the engagement between the sensing arm and the rotating cam mechanism. This ensures that the eject operation is performed when the vehicle is stopped.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing a cassette deck according to the present invention, FIG. 2 is a schematic side view thereof, and FIGS. 3 to 5 are diagrams for explaining the cassette loading operation.
Figures 6 to 9 are diagrams for explaining the cassette eject operation, Figure 10 is a schematic plan view of the reel unit drive mechanism in Figure 1, and Figure 11 is a schematic plan view of the reel unit drive mechanism in Figure 1.
Fig. 12 is a block diagram of the FF/REW power transmission mechanism section, Fig. 12 is a block diagram of the constant speed/high speed power transmission mechanism section, Fig. 13 is a block diagram showing an example of the sensing mechanism, and Fig. 14 shows the reset operation of the sensing mechanism. Figures 15 and 16 are diagrams for explaining the operation of the selection lever and sensing power lever, Figure 17 is a diagram for explaining the unlocking operation of the lock arm, and Figure 18 is a diagram for explaining the operation of the lock arm. Figure 19 is a diagram for explaining the forward movement of the head base, Figure 20 is a diagram for explaining the unlocking operation of the head base, Figures 20 and 21 are
The figure is a diagram for explaining FF and REW operations, the second
Figures 2a and 2b are a plan view and a side view showing the positioning of the FF lever with respect to the grille opening. Explanation of symbols of main parts, 2...Cassette push lever, 3...First arm, 4...First lever, 6
... Second lever, 8 ... Third lever, 11 ... Swing lever, 12 ... Regulation arm, 13 ... Lock arm, 15 ... Cassette half, 16 ... Cassette holder, 25 ... Head, 28 ... ...FF lever, 29...REW lever, 34...grill,
37...Second arm, 42...Selection lever, 50
... Motor, 53 ... Flywheel gear, 55
... Capstan, 57 ... Idler arm, 6
0, 63... Reel unit, 62... Sensing release arm, 68... Head stand, 74... Idler gear, 81... Cam gear, 84... Sensing arm, 89... Reset arm, 100...
pinch roller.

Claims (1)

[Scope of Claims] 1. A starting mechanism for an eject mechanism that should automatically operate in response to the stoppage of rotation of a reel unit in a cassette deck, comprising: a rotary cam mechanism 82 powered by the reel unit drive motor 50; and a reciprocating mechanism. a power lever 85 which is freely provided and controls activation of the eject mechanism on its outward path; and a power lever 85 which is pivotally supported by the power lever and engages with the rotary cam mechanism when the rotation of the reel unit is stopped, thereby causing the power lever to move in the forward direction. a sensing arm 84 that is movable; a biasing means 88 that returns the power lever when the rotation cam mechanism and the sensing arm are disengaged; and a biasing means 88 that is movable to engage the cassette half 5 loaded in the playing position and a reset arm 89 provided therein, wherein the reset arm swings the sensing arm to forcefully release the engagement with the rotary cam mechanism when the cassette half is ejected. Mechanism activation mechanism.