Dual spring loaded operating mechanism for a tape recorder

A tape recorder capable of pressing a pinch roller against a capstan shaft with a slight pressing force in the pause state which includes an operation lever reciprocally moved by interlocking with recording, reproducing and stopping operations; a rotational lever rotated by interlocking with the operational lever and effected by a predetermined biasing force; a pinch roller supporting metal fitting interlocking only with the rotation in response to the recording or reproducing operation of the rotational lever and given the biasing force as a force pressing the pinch roller against the capstan shaft; a small spring having a comparatively small biasing force interposed between the supporting metal fitting and the rotational lever; and a play lever reciprocally moved by interlocking with the recording, reproducing and stopping operations, so as to rotate the pinch roller supporting metal fitting and to make the pinch roller contact the capstan shaft.

BACKGROUND OF THE INVENTION 
The present invention relates to a tape recorder capable of pressing a 
pinch roller against a capstan shaft with a slight pressing force under 
the state of a temporary stop on the way to recording or reproduction, 
that is, the state of a pause. 
Some tape recorders are provided with a so-called pause function for 
temporarily stopping a tape from running during recording or reproduction. 
As an example of such tape recorder, a motor drive circuit is cut off as a 
pinch roller is pressed against a capstan shaft and a tape running is 
temporarily stopped. 
If a pinch roller is pressed against a capstan shaft with a large pressing 
force at the time of recording or reproduction during the state of a 
pause, the pressing force in such a case is considerably larger, so that 
the pinch roller becomes deformed by the pressing force against the 
capstan shaft when the pausing state is continued for a long time, and 
then thereafter, the tape running cannot be performed smoothly, and 
recording and reproduction become unstable in characteristic. 
In order to eliminate such a disadvantage, a tape recorder has been 
proposed where tape running is temporarily stopped by cutting out a motor 
drive circuit and at the same time the pinch roller is separated from a 
capstan shaft. 
If the pinch roller is separated from the capstan shaft under the state of 
a pause, a tape is displaced downward by its own weight caused by 
slackened tension of the tape. When the tape recorder is restarted under 
such state, the tape becomes unstable in characteristic for recording and 
reproduction on that portion because the tape is started from the 
displaced state. 
SUMMARY OF THE INVENTION 
An object of the present invention is to eliminate the above disadvantages 
of conventional tape recorders. 
Another object of the present invention is to provide a tape recorder which 
can prevent the deformation of the pinch roller by pressing the pinch 
roller against a capstan shaft with a slight force when it is under the 
state of a pause and also can prevent the displacement of the tape, 
thereby stabilizing the characteristic at the time of recording and 
reproduction. 
According to the present invention the tape recorder comprises an operation 
lever reciprocally moved by interlocking with recording, reproducing and 
stopping operations; a rotational lever rotated by interlocking with the 
operational lever and effected by a predetermined biasing force; a pinch 
roller supporting metal fitting interlocking only with rotation in 
response to the recording or reproducing operation of the rotational lever 
and providing the biasing force as a pressure force directing the pinch 
roller against the capstan shaft; a small spring having a comparatively 
small biasing force interposed between the supporting metal fitting and 
the rotational lever; and a play lever reciprocally moved by interlocking 
with the recording, reproducing and stopping operations, so as to rotate 
the pinch roller supporting metal fitting and to make the pinch roller 
contact the capstan shaft. The operation lever is only stopped temporarily 
on the way of recording or reproduction, the interlocking action of the 
supporting metal fitting with the rotation lever is released, and the 
pinch roller is pressed against the capstan shaft by the biasing force of 
the spring.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIG. 1 one embodiment of a tape recorder according to the 
present invention will be described. In FIG. 1, reference numeral 1 is an 
operation lever, and this lever 1 is interlocked with recording, 
reproducing and stopping operations and is linearly and reciprocally moved 
in the direction of the arrow shown in FIG. 1 alongside the lever. The 
illustrated embodiment shows the lever 1 in the state of moving 
downwardly, that is, the state of recording or reproducing state. The 
lever 1 is also interlocked with the stopping operation against a pause 
operation. 
At an end portion of the lever 1 an elongated hole is formed extending in 
the axial direction and into the elongated hole 1a a pin 3 secured on a 
rotational lever 2 is inserted. 
The rotational lever 2 is arranged at a right angle to the operation lever 
1 and is rotatably supported about an axis 4 at its center portion, so 
that the lever 2 is rotated in response to the linear reciprocating 
movement of the operation lever 1. Adjacent the illustrated end of the 
operation lever 1, the rotational lever 2 is provided with a spring hook 
portion 5, and a tension spring 6 is secured to the spring hook portion 5. 
The spring 6 determines the pressing force of a pinch roller 8 against a 
capstan shaft 9, which will be explained later on, at the time of 
recording or reproduction, and the rotational lever 2 is rotated and 
biased in the counterclockwise direction by this tension force. 
Reference numeral 7 is a pinch roller supporting metal fitting, and this 
pinch roller supporting metal fitting 7 is formed into a U-shape, one end 
of which rotatably supports a pinch roller 8 and the other end rotatably 
pivots around the axis 4. In this case, the supporting metal fitting 7 
positions a U-shaped bottom surface 7a on the side of a capstan shaft as 
illustrated, an end of the rotational lever 2 is in contact with the 
bottom surface 7a and the pinch roller 8 is in contact with the capstan 
shaft 9 by interlocking with the rotation of the rotational lever 2 in the 
counterclockwise direction. FIG. 1 shows this state. A spring 10 is 
secured between the supporting metal fitting 7 and the rotational lever 2, 
as shown in FIG. 2. The spring 10 determines a pressing force of the pinch 
roller 8 against the capstan shaft 9 under the state of a pause, and the 
supporting metal fitting 7 is rotated and biased in the counterclockwise 
direction shown in FIG. 1 against the rotational lever 2 by its deviation 
force. In this case, the pressing force of the pinch roller 8 under the 
state of a pause is set less than 1/2 of the pressing force at the time of 
the above-described recording or reproduction. 
The supporting metal fitting 7 is provided with a downwardly extending pin 
11, upwardly as shown in FIG. 2. The pin 11 is inserted into a 
through-hole 12a of a play lever 12. 
The play lever 12 with a magnetic head (not shown) thereon interlocks with 
the recording, reproducing and stopping operations, and moves linearly and 
reciprocally in the direction of an arrow shown in FIG. 1, so that the 
lever 1 advances the magnetic head to a tape position when recording or 
reproducing, and simultaneously rotates the supporting metal fitting 7 
through the pin 11 in the counterclockwise direction so as to make the 
pinch roller 8 contact the capstan shaft 9, to withdraw the magnetic head 
when stopping, simultaneously to rotate the supporting metal fitting 7 
through the pin 11 in the clockwise direction, and to separate the pinch 
roller 8 from the capstan shaft 9. FIG. 1 shows the lever 12 moved 
upwardly under the state of recording and reproduction state, in which the 
magnetic head (not shown) is advanced and the pinch roller 8 is 
simultaneously placed into contact with the capstan shaft 9. In this case, 
the play lever 12 remains interlocked with the recording and reproducing 
operations against the pause operation. 
The action of the tape recorder according to the present invention 
constructed as described above will be explained hereinafter. As shown in 
FIG. 1, when the operation lever is in the illustrated state by 
interlocking with the recording or reproducing operation, the rotational 
lever 2 is rotated in the counterclockwise direction around the axis 4 and 
its end presses against the pinch roller supporting metal fitting 7. In 
this case, the play lever 12 is also interlocked by the recording or 
reproducing operation and remains in the state shown in FIG. 1, so that 
the supporting metal fitting 7, interlocked with the rotational lever 2, 
is rotated in the counterclockwise direction and presses the pinch roller 
8 against the capstan shaft 9. 
In this case, the tension force of the spring 6 is applied to the 
rotational lever 2 rotating is in the counterclockwise direction. 
Therefore, the tension force in this case acts as a pressing force via the 
pin 4 on roller 8. 
When the pause operation is performed from the above state, the operation 
lever 1 is moved upwardly only as shown in FIG. 1. Then, the rotational 
lever 2 is rotated around the axis 4 in the clockwise direction, and the 
pressure of the pinch roller supporting metal fitting 7 is released at the 
end. However, in this case, the play lever 12 still remains in the state 
shown in FIG. 1 against the pause state, so that, in this state, the pinch 
roller supporting metal fitting 7 is rotated in the counterclockwise 
direction by the bias force of the spring 10 and the pinch roller 8 is 
made into contact with the capstan shaft 9. That is, under such pause 
state, the pinch roller 8 is pressed to the capstan shaft 9 by the slight 
biasing force of the spring 10. 
Then, when operation is switched from the pause to the above recording or 
reproducing state, if the stop operation is performed, the operation lever 
1 is moved upwardly as shown in FIG. 1 and at the same time, the play 
lever 12 is moved downwardly as shown in FIG. 1, so that the rotational 
lever 2 interlocked with the operation lever 1 is rotated in the clockwise 
direction around the axis 4 so as to release the pressure of the pinch 
roller metal fitting 7 at the end. Further, with the downward movement of 
the play lever 12, as shown in FIG. 1, the through-hole 12a is also moved 
to the position shown by a one dot dash line as illustrated. Thus, the 
pinch roller supporting metal fitting 7 is rotated in the clockwise 
direction by the pin 11, and the pinch roller 8 is separated from the 
capstan shaft 9. 
With such construction, in the pause state on the way to the recording or 
reproduction, the pinch roller can be brought into contact with the 
capstan shaft with a slight pressing force, so that the deformation of the 
pinch roller is prevented even if the pause state is continued for a long 
time as compared to conventional operation in which the pinch roller is 
pressed against the capstan shaft with a large pressing force during 
recording or reproduction, and as a result, instability in characteristic 
at the time of recording or reproduction caused by such deformation can be 
avoided. Further, as compared with the condition in which the pinch roller 
is separated from the capstan shaft simultaneously with the pause state, 
it becomes possible to avoid the disadvantage that the tape is displaced 
downward by its own weight. Therefore, the subsequent re-start of 
recording or reproduction stably can be carried out in a stable manner. 
The present invention is not limited to the above embodiment but can be 
modified without departing from the essential feature of the present 
invention. 
As stated hereinbefore, the present invention provides a tape recorder for 
stabilizing the characteristic at the time of recording or reproduction by 
pressing a pinch roller against a capstan shaft with a slight force in the 
pause state, thereby preventing not only the deformation of the pinch 
roller but also the displacement of the tape.