Automatic music selecting device for tape recorder

A power assist type tape recorder including an automatic music selecting mechanism in which a head base can be stopped at a music selecting position between a stop position and a play position for automatically selecting recorded portions on a tape. A drive gear is coupled coaxially to a flywheel and a reduction gear having a cutaway portion is disposed adjacent the drive gear with the reduction gear being engageable with the drive gear and movable between a stop position and a play position. An eccentric cam mounted on the reduction gear abuts the rear end of a head base upon which is mounted a reproducing head. A music selection position stop mechanism including a music selecting plunger and a stop lever coupled to the plunger stop the head base at a music selection position.

BACKGROUND OF THE INVENTION 
The present invention relates to a tape recorder, more particularly to an 
automatic music selection or automatic tape leader feeding mechanism for a 
cassette tape recorder. 
There have been previously provided two types of such automatic music 
selecting or tape leader feeding mechanisms for cassette tape recorders. 
In one type, an additional head for detecting a recording position on a 
tape is used. In the other type, a reproducing head is also used to 
perform the detecting function. In the former case, the provision of such 
a detecting head causes an increased production cost. 
In the case where the reproducing head is also used therefor, the music 
selection mechanism operates as follows. When an operatonal switch of the 
cassette tape recorder is changed over from a play mode to a music 
selecting mode position, a head base on which the reproducing head is 
mounted is moved by about 1 mm to 1.5 mm rearwardly and the recording 
position is detected by the head, which is still in contact with the tape. 
At the same time, corresponding to the rearward movement of the head base, 
various mechanism such as a constant rate tape feeding mechanism, a reel 
drive, and a brake mechanism are inoperative whereas a fast forwarding and 
rewinding mechanism is operated so as to fast forward or rewind the tape. 
In the above described prior art construction, it is very difficult to 
directly control the various mechanisms according to the head base 
movement of about 1 mm to 1.5 mm. Accordingly, in addition to a plunger 
for the play mode which serves to move the head base to the play position, 
a large capacity plunger producing the same torque as that of the play 
plunger is needed for controlling the above described various mechanisms. 
This leads to complexity of construction with an accompanying high cost. 
Also, a great amount of electric power is needed therefor. 
Recently, there has been provided a cassette tape recorder having an 
electric mode operation mechanism in which a large capacity play plunger 
is dispensed with and, instead, a power assist mechanism is used. Such a 
mechanism will be more specifically described. In such a mechanism, a 
small capacity compact plunger of an energy-saving type is used to move 
the mechanical parts to a play position with only a small torque. A 
reduction gear having a cutaway portion, which is rotated when the compact 
plunger is activated by use of the same switched electric supply, is 
engaged with a drive gear fixed to a rotatable shaft coaxially with a 
flywheel. As a result, a high drive torque is obtained using gear 
reduction. The head base on which the reproducing head is mounted is 
advanced to the play position through a cam fixed coaxially with the 
reduction gear. When the electric supply to the compact plunger is 
stopped, the cam is returned to thereby move the head base back to the 
stop position. 
With this construction, since the head base is driven using the drive gear, 
the motion thereof is limited to two types, namely, the head base can be 
moved from the play position to the stop position and vice versa. During 
these operations, the flywheel is always rotated. Therefore, it is 
impossible to stop the head base at the music selecting position between 
the stop position and the play position. 
SUMMARY OF THE INVENTION 
Accordingly, the present invention provides an improved tape recorder 
having a power assist mechanism overcoming these drawbacks. The invention 
specifically provides an automatic music selecting mechanism wherein, when 
a reduction gear is disengaged from a drive gear at its cutaway portion, a 
head base is stopped at a music selecting position by a music selection 
stopping mechanism, a reproducing head is in contact with the tape, 
mechanisms such as a brake mechanism are inoperative, and at the same time 
fast forwarding or rewinding of the tape is possible. 
More specifically, the invention provides a power assist type tape recorder 
including an automatic music selecting device composed of a drive gear 
attached rigidly to a flywheel and mounted coaxially therewith and a 
reduction gear having a cutaway portion with the reduction gear being 
engageable with the drive gear and being movable between a stop position 
and a play position. An eccentric cam is mounted on the reduction gear 
abutting a head base upon which a reproducing head are mounted for 
detecting a recorded signal on a tape. A rotation control mechanism 
controls the rotational position of the reduction gear. A music selection 
position stopping mechanism composed of a music selecting plunger and a 
stop lever coupled to the plunger stop the head base at a music selecting 
position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention will now be described with reference to the 
accompanying drawings. FIG. 1 is a schematic view showing a construction 
of a tape recorder with an automatic music selecting mechanism according 
to the present invention. FIG. 2 is a view similar to FIG. 1, illustrating 
an operation of a primary part of the tape recorder. In FIGS. 1 and 2, 
reference numeral 1 designates a winding reel disc, 2 a feed reel disc, 3 
a motor, 4 a motor pulley fixed to an output shaft of the motor 3, 5 an 
intermediate idler which is always maintained in contact with the winding 
reel disc 1, and 6 a drive pulley to which a small pulley 7 is fixed 
coaxially therewith. A belt 8 passes around the drive pulley 6 and the 
motor pulley 4 to thereby transmit torque from the motor 3 to the pulley 6 
therethrough. The drive pulley 6 is rotatably attached to a free end of an 
arm 10 which is pivoted at a shaft 9. The drive pulley 6 is alternately 
positionable in contact with the intermediate idler 5 and feed reel disc 2 
by a fast forward plunger (solenoid) 11 coupled to the arm 10 and a 
rewinding plunger 12 also coupled thereto. A fast forward and rewinding 
mechanism 14 for a tape 13 is composed of the intermediate idler 5, the 
drive pulley 6, the fast forward plunger 11 and the rewinding plunger 12. 
Reference numeral 15 denotes a winding idler which is frictionally 
engageable with the winding reel disc 1 or the small pulley 7. A reel 
drive mechanism 16 is composed of the three members 1, 7 and 15. 
Reference numeral 17 denotes a flywheel to which rotational torque from the 
motor 3 is transmitted through a belt 49 which passes around the motor 
pulley 4. Any appropriate driving structure for this may be used, for 
example, an idler drive for the flywheel 17. Reference numeral 18 denotes 
a capstan fixed to the flywheel 17. 
Reference numeral 19 denotes a small diameter drive gear fixed to the 
flywheel 17 coaxially therewith and 20 a large diameter reduction gear 
which is arranged to meshingly engage with the drive gear 19 but which has 
a cutaway portion 20a at its periphery. An upright pin 21 is fixed to an 
outer surface of the reduction gear 20 and an eccentrically-shaped cam 22 
is fixed to the shaft of the reduction gear. 
Reference numeral 23 denotes a rotation control mechanism for the reduction 
gear 20 including a stop lever 24 and an energy saving type compact play 
plunger 25. The stop lever 24 is pivotally mounted at its midpoint on a 
shaft 26 and is bifurcated from the shaft 26 on the right to thereby form 
two stop arms 28 and 29, one stop arm 28 having at its end a stop claw 
28a. The other end of the stop lever 24 is coupled to the plunger 25. 
Reference numeral 30 denotes a stop spring for biasing the stop lever 24 
clockwise and 31a and b denote stop pins for the stop lever 24. 
Reference numeral 32 denotes a head base which is linearly movable guided 
by a guide groove 33 and a pin 34. Reference numeral 35 designates a 
spring for biasing the head base 32 toward the rear. A reproducing head 36 
serves also as a recording head in the embodiment shown. The reproducing 
head 36, an erasing head 37 and a pinch roller 38 are mounted on the head 
base. Reference numeral 39 denotes a support arm for supporting rotatably 
the pinch roller 38 thereon. A spring force is applied to the support arm 
39 by a spring (not shown) so that the pinch roller 38 is biased to rotate 
toward the front around a shaft 40. Reference numeral 41 denotes a stop 
pin for the arm 39. A constant speed drive mechanism 42 is composed of the 
pinch roller 38 and the capstan 18. The cam 22, provided coaxially with 
the reduction gear 20, is in contact with the rear edge 32a of the head 
base 32. 
The relationship among the reduction gear 20, the cam 22 and the rotation 
control mechanism will now be described. First, in the stop condition as 
shown in FIG. 2, the stop lever 24 is stopped at the stop pin 31b by the 
spring force of the spring 20 whereas the other stop arm 28 is engaged 
with the pin 21 at the stop claw 28a so as to prevent the reduction gear 
20 from rotating clockwise. At this time, the reduction gear 20 faces the 
drive gear 19 at the cutaway portion 20a and the cam 22 pushes the rear 
edge 32a of the head base 32 against the biasing force of the spring 35 
with the cam being slanted by an angle of d with respect to a horizontal 
line X. In this case, the biasing force of the spring 30 is greater than 
that of the spring 35. 
Subsequently, in the play mode, as shown in FIG. 3, by operation of the 
play plunger 25, the stop lever 24 is stopped at the stop pin 31a, the pin 
21 is stopped so as to not to be rotated by the other stop arm 29, and the 
reduction gear 20 faces the drive gear 19 at its cutaway portion 20a. At 
this time, the cam 22 holds the head base 32 at the play position with the 
cam being slanted slightly from a vertical line Y toward the right. It it 
to be noted that the cam 22 must be slanted in any condition of stop and 
play on the right hand as described above. Thus, in changing from the stop 
mode to the play mode, a rotational torque is applied to the reduction 
gear 20. 
Reference numeral 43 designates a selecting position stopping mechanism for 
the head base 32 composed of a stop lever 45 rotatable about a shaft 44, a 
compact music selecting plunger 46 coupled to an end of the lever 45, and 
a spring 47 for biasing the stop lever 45 clockwise. When the stop lever 
45 is stopped by the stop pin 48, as the rear edge 32a of the head base 32 
is in contact with the free end 45a of the lever 45, the head base is 
positioned at the selecting position. 
The operation of the thus constructed device will now be described. 
When the mode is changed from the stop mode shown in FIG. 2 to the play 
mode shown in FIG. 3, the play plunger 25 is operated so that the stop 
lever 24 is rotated counterclockwise against the force of the spring 30 
about the shaft 26 and then is stopped in abutment with the stop pin 31a 
and simultaneously therewith disengages the stop claw 28a of the stop arm 
28 from the pin 21 to thereby allow the reduction gear 20 to freely 
rotate. On the other hand, the cam 22 provided coaxially with the 
reduction gear 20 is pushed by the head base 32 moved rearwardly by the 
force of the spring 35 so that the cam 22 is rotated clockwise through an 
angle of .alpha.. By the rotation of the cam 22, the gear portion of the 
reduction gear 20 is engaged with the drive gear 19 coaxially fixed to the 
flywheel 17 so that the reduction gear 20 is rotated clockwise through one 
rotation. As a result, while the cam 22 is in contact with the rear edge 
32a of the head base 32, the head base 32 is thereby advanced against the 
spring force of the spring 35. Then, when the end portion of the cam 22 is 
positioned slanted slightly from the vertical shaft Y toward the right, 
the cam 22 is moved downwardly by action of the spring 35. Accordingly, 
the reduction gear portion of the reduction gear 20 is disengaged from the 
drive gear 19 to allow the cutaway portion 20a to face the drive gear 19. 
At the same time, the pin 21 is in contact with the tip end of the stop 
arm 29 to thereby prevent rotation of the reduction gear 20. Thus, the 
head base 32 is stopped at the play position and the reproducing head 36 
and the erasing head 37 are in contact with the tape 13. At the same time, 
the pinch roller 38 is in contact with the capstan 18 to thereby feed the 
tape 13 at a constant rate while, by the movement of the winding idler 15 
into the space between the winding reel disc 1 and the small pulley 7 at a 
predetermined angle, the tape is wound on the reel. 
Next, when the mode is changed over to the selecting condition (with 
reference to FIG. 4), the play plunger 25 is operated so that the 
mechanism is then in the play mode as described above. Immediately 
thereafter, the rotation control mechanism 23 is rendered inoperative in 
the stop condition while the music selecting position stopping mechanism 
43 is operated so that the head base 32 is stopped at the selecting 
position. That is, immediately after reaching the play mode, the play 
plunger 25 is inoperative for the rotation control mechanism 23. Therefore 
the stop lever 24 is rotated clockwise by action of the spring 30 and 
stopped at the stop pin 31b whereas the pin 21 is disengaged from the stop 
arm 29 end to thereby allow the reduction gear 29 to freely rotate. 
Accordingly, the cam positioned at the stop position is rotated clockwise 
by the rearward movement of head base 32 due to the force of the spring 35 
while at the same time rotation of the cam 22 allows the pin 21 to move 
toward the stop claw 28a of the stop lever 28. On the other hand, when the 
electric plunger 25 is stopped, the music selecting plunger 46 of the 
music selecting position stopping mechanism 43 is operated so that the 
stop lever 45 is rotated to stop at the stop pin 48 against the action of 
the spring 47. At this time, the head base 32 which is now moved toward 
the above described stop position is stopped at the music selection 
position so that the rear edge 32a of the head base 32 is in contact with 
the free end 45a of the stop lever 45. It should be noted that the 
rearward movement distance of the head base from the play position to the 
music selecting position is about 1 mm to 1.5 mm. In this state the 
reproducing head 36 is still in contact with the tape 13 and the pinch 
roller 38 is separated from the capstan 18. Therefore, the reel drive 
mechanism 16, the brake mechanism and the related components are rendered 
inoperative or released. When the fast forward and rewinding mechanism 14 
is operated by the fast forward plunger 11 and the rewinding plunger 12, 
respectively, and the tape is run in the fast forword or rewinding mode, a 
signal recorded on the tape 13 is detected by the reproducing head 36 in 
response to which the electric supply to the music selecting plunger 46 is 
interrupted so that the stop lever 45 is rotated counterclockwise by the 
force of the spring 47. As a result, the head base 32 is moved rearwardly 
to the stop position by the spring 35 while at the same time the tape 13 
is stopped by a non-signal portion between one music recorded portion on 
the tape and another adjacent thereto. At this time, electric power is 
supplied to the plunger 25 to start the play operation whereupon the 
signal recorded on the tape 13 is again reproduced. 
As mentioned above, the power assist type tape recorder of the invention 
includes a drive gear 19 fixed to the flywheel 17 coaxially therewith, a 
reduction gear 20 having a cutaway portion 20a with the reduction gear 20 
being engageable with the drive gear 19 and coaxially coupled to a cam 22 
for moving between the stop condition and the play condition the head base 
32 upon which is mounted the reproducing head 36 for detecting a recorded 
signal on the tape 13, and a rotation control mechanism 23 for controlling 
rotation of the reduction gear 20. The present invention futher includes a 
music selecting position stopping mechanism 43 coupled to a play plunger 
46 and a stop lever 45 coupled to the plunger 46, whereby the head base 32 
is stopped at a music selecting position by the stop lever 45. With this 
construction, it is possible to automatically select the recorded music on 
the tape with the power assist type recorder. Since a rotational torque 
only large enough to stop the head base 32 is required for the music 
selecting plunger 46, the tape recorder can be miniaturized.