JPH0319070Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of an auto-reverse mechanism in a cassette-type tape player.

<Prior art> Traditionally, cassette-type tape players have been equipped with an automatic system that automatically reverses the running direction of the tape when one side of the tape ends during recording or playback, and performs continuous operation to record and play back the other side. Some use a reverse mechanism. In order to perform the reversing operation, this auto-reverse mechanism has a reversing mechanism that operates semi-electrically using mainly a plunger, and a mechanical reversing mechanism that uses multiple gears and cams and uses the driving force of a motor. The former type of reversing mechanism has a relatively simple structure and the reversing operation can be performed in a short time, but it consumes a lot of power and has the disadvantage of producing a lot of noise during the reversing operation. have. On the other hand, the latter reversing mechanism utilizes the driving force of a motor, so its power consumption is low, and the rotational movement makes the operation quiet. However, the structure is complicated, and the reversing operation is particularly slow (2 to 3 Sec.) had drawbacks.

Here, the latter auto-reverse mechanism having a reversing mechanism that utilizes the driving force of the motor will be explained with reference to FIG.
A belt 5 is wound around the outer periphery of the flywheels 3 and 4, and the flywheels 3 and 4 are rotated in different directions by a motor 6. Pinch rollers 7 and 8 are provided near the capstans 1 and 2 and are urged outward by springs 9 and 9, and one of the pinch rollers 7 slides the reversing lever 11 in the longitudinal direction. The pull-up lever 10 rotates and pulls up the tape, and presses the tape against the capstan 1 to run the tape in a predetermined direction. At the same time, the relay selection lever 12 is rotated by the reversing lever 11, and the rotation of the pulley 13, which is driven by the belt 5 provided on its central axis, is transferred to the take-up reel shaft (positive The direction is transmitted to the reel shaft (for reproducing) 16, and a take-up reel (not shown) in the tape cassette is rotated to wind up the tape. Furthermore, when the reversing lever is slid in the opposite direction, the pinch roller 8 is brought into pressure contact with the capstan 2 in the same way as in the above operation,
The tape can be run in the opposite direction by rotating the take-up reel shaft (reel shaft for reverse playback) 17.

The reversing mechanism that slides the reversing lever 11 includes:
The cam 18 is slid by making a half turn, and the intermittent gear 20 that drives the gear 21 provided on the cam has a notch 20a on its circumference.
The notch 20a cuts off the rotational force of the shaft 19a of the pulley 19 rotated by the belt 5 and unlocks the intermittent gear, thereby meshing the shaft 19a and the intermittent gear 20. The cam 18 is rotated through the gear 21 by a half turn.

Therefore, when one side of the tape is finished, the intermittent gear is unlocked, and when the intermittent gear is rotated once by the shaft portion 19a of the pulley 19, the gear 21, that is, the cam 18, is rotated by half a rotation, and the reversing lever is slid.
The pinch roller and take-up reel shaft are switched to perform the reversing operation.

<Purpose> The present invention eliminates the disadvantage that the reversing operation of the auto-reverse mechanism with the above configuration is slower than that using a plunger. This provides an auto-reverse mechanism that shortens the time.

<Embodiment> Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is an enlarged view of the surrounding area around the intermittent gear 20 in FIG. A locking protrusion 20b is provided on the circumference,
A lock lever 22 having a plunger 23 at its rear end is fitted in the direction of rotation of the lock projection 20b to lock the intermittent gear. Further, a switch cam 20c is provided on the same axis as the intermittent gear, and the top of the switch cam 20c is pressed against a pressing lever 24 which is biased by a spring 25 in the direction of rotation of the cam. A switch 26 is provided at the rear end of the pressing lever 24 to close the contact when the intermittent gear rotates. As shown in FIG. 3, this switch 26 is connected in parallel to a governor circuit 27 for rotating the motor 6 at a constant speed, and passes through the governor circuit when the intermittent gear rotates.

Therefore, when one side of the tape ends, the plunger 23 is actuated by the tape end signal to release the engagement between the locking lever 22 and the locking protrusion 20b, and the pressing piece 24 releases the switch cam 20c.
is rotated, the shaft portion 19a of the pulley 19 and the intermittent gear 20 are fitted together, and at the same time the intermittent gear 20 is rotated once, the gear 21, that is, the cam 21 is rotated by half a rotation, and the reversing lever 11 is slid. At this time, the switch 26 at the rear end of the pressing lever 24 is closed until the switch cam 20c of the intermittent gear 20 rotates once.
Since the governor circuit 27 of the motor 6 is passed, the rotation speed of the motor 6 becomes faster, and therefore the rotation of each of the gears described above is also accelerated, and the reversing operation can be performed quickly.

<Effects> As described above, in the auto-reverse mechanism of the cassette-type tape player of the present invention, the intermittent gear that rotates the cam that slides the reversing lever is provided with a switch that closes the contact during its rotation, and this switch is connected to the motor. Because it is connected in parallel with the governor circuit,
Since the governor circuit of the motor is passed only during the reversing operation to increase the rotation speed, the reversing operation can be accelerated and the reversal can be performed in a short time.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a conventional auto-reverse mechanism, Fig. 2 is an enlarged view showing the main parts of the auto-reverse mechanism in the cassette tape player of the present invention, and Fig. 3 is a block diagram of the main circuits in the auto-reverse mechanism. It is a diagram. 6... Motor, 18... Cam, 19... Pulley, 19a... Shaft, 20... Intermittent gear, 20a
...Notch, 20c...Switch cam, 24...
Pressure lever, 26... switch, 27... governor circuit.

Claims (1)

[Claims for Utility Model Registration] When one side of the tape is finished, the intermittent gear is unlocked and rotated by a motor to a predetermined degree, and the intermittent gear rotates a cam to slide the reversing lever in the longitudinal direction. Based on the sliding of the reversing lever, the pinch roller for forward playback is separated from the capstan for forward playback, and the transmission roller for rotating the reel shaft is separated from the reel shaft for forward playback, and the pinch roller for reverse playback is moved away from the reel shaft for forward playback. In an auto-reverse mechanism for a cassette-type tape player in which a roller is pressed against a capstan for reverse playback and the transmission roller is pressed against a reel shaft for reverse playback to reverse the tape running direction, while the intermittent gear is rotating. A switch is provided to close the contact, and this switch is connected in parallel with a governor circuit that rotates the motor at a constant speed, thereby increasing the rotational speed of the motor during reversing operation and shortening the reversing time. Auto-reverse mechanism in a cassette tape player.