JPS6032151A - Shut-off mechanism - Google Patents

Abstract

PURPOSE:To simplify a shutoff mechanism by performing a shutoff action when a tape ends in a record or reproduction mode and inhibiting the shutoff action in case the tape ends in rapid traverse and rewind modes respectively. CONSTITUTION:In a record or reproduction mode a magnetic tape 8 is driven toward an arrow (f) at a fixed speed by the revolutions of a capstan 9 toward an arrow (e), and a pinch roller is rotated toward an arrow (g). In this case, the center shaft of the pinch roller is also turned toward (g) together with the roller. Therefore a shutoff levr is rotated by the frictional force produced with a rotary shaft part by a biting action to a wedge-shaped slit in a record or reproduction mode. Thus a pin 27 to be driven at the tip of an arm 25 of a shutoff lever is always pressed to the eccentric cam surface of the 1st vam 40 of a cam gear 37. At the same time, the gear 37 is rotated at a low speed by the capstan 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mechanical shutoff mechanism that is most suitable for application to recording and reproducing devices such as tape recorders and VTRs. [Background Art and Problems Therewith] As is well known, a mechanical shutoff mechanism mechanically detects when tape running is stopped due to a tape end or the like during tape running in recording or playback mode. A shut-off lever is driven in a predetermined direction by a drive body that is constantly driven by a motor to automatically switch to a stop mode.

By the way, in many conventional mechanical shutoff mechanisms, the shutoff operation is performed at the end of the tape in recording or playback mode, but not at the end of the tape in fast forward or rewind mode. but,
The mechanism for avoiding engagement of the shutoff lever with the driver in fast forward or rewind mode is very complex.

[Object of the Invention] The present invention provides a mechanical system configured to perform a shut-off operation at the end of the tape in recording or playback mode, but not to perform the shut-off operation at the end of the tape in fast forward or rewind mode. An object of the present invention is to provide a very simple shutoff mechanism for avoiding engagement of the shutoff lever with the drive body in fast forward or rewind mode.

[Summary of the invention]

In the recording or playback mode, the present invention moves to the forward position! II
A reciprocating rotating body is provided which is moved back to the backward position in the fast forward or rewind mode, and this rotating body is rotated as the tape runs while being moved forward to the forward position. At the same time, the rotation is stopped when the tape running stops, and an rc is added to the rotary body, which is a shut-off lever, so as to be slidable in a direction orthogonal to the axis of the rotating body and rotatable around the axis; When the rotary body is moved forward to the forward position, it comes into contact with the first contact portion of the shut-off lever to urge the shut-off lever to slide in one direction, and the rotary body When the lever is vibrated to the return position, it comes into contact with the second contact part of the above-mentioned shut-off lever, and this shut-off lever ? A biasing spring is provided that biases rotation in a direction opposite to the rotating direction of the rotating body, and in the recording or playback mode, the shutoff lever is slidably biased to frictionally engage with the rotating body. When the tape running in the recording or playback mode is stopped and the rotational bias of the rotary body is released, the shut-off lever is activated. is engaged with a driving body and the driving body drives the shutoff lever in a predetermined direction to perform the desired shutoff operation, and in fast forward or rewind mode, the shutoff lever is rotated as described above. The shutoff mechanism is configured to avoid engagement of the shutoff lever with the drive body by biasing the shutoff lever in a direction opposite to the direction of rotation of the body.

The margin below E continues to the next negative. [Embodiment] Hereinafter, an embodiment of a shutoff mechanism in which the present invention is applied to a small cassette tape recorder will be explained based on the drawings. First, in Figs. is composed of a pinch roller il+.0 pinch roller [11 is a roller support shaft (
The pinch roller lever (21 is rotatably supported via the fulcrum shaft (4)
The pinch roller pressure spring (6
1 in the direction of the arrow a in FIG.

In the stop mode, the play button (force) is moved to the return position shown by the imaginary line in FIG. The pinch roller (11) is moved back to the return position shown by the imaginary line in FIG.

Next, when the play button [7J is pressed in the direction of arrow C in FIG. 3 and moved forward to the forward position shown by the solid line to switch to the recording or The pinch roller 11 is moved forward in the direction indicated by the arrow in the figure against the spring, and the pinch roller 11 is moved forward to the forward position shown by the solid line in FIG. 2 by the pinch roller lever 121K. At this time, the pinch roller (1) is inserted into the tape cassette (not shown), and the pinch roller pressure spring (61) pushes the magnetic tape (81) in the tape cassette against the capstan (9).
Crimp it. As a result, the capstan (91) is driven by a motor (not shown) and rotated in the direction of the arrow e in FIG. At this time, as the mountain tape f87 (7) runs at a constant speed in the direction of arrow f, the pinch roller +11 is driven to rotate in the direction of arrow g in FIG.

- The play button lever (10) to which the 17"V button (7) is fixed is moved back together with the play button (7) in the direction of arrow C in FIG. 3 against a spring (not shown). The lock plate t111 is rotatably supported on the chassis u2 via the fulcrum shaft tI:ll, and is locked by the lock plate t111 at the forward position shown by the solid line. figure〕
3, the lock pawl αψ is engaged in the locking hole a9, the play button is pressed, and the bar is locked in the forward movement position.

Next, the fulcrum shaft t13191 of the lock plate tID! At the end of l, there is a shut-off operation bottle U extending upwardly from this point.
1 is fixed vertically to the. And as explained later,
When you are in recording or playback mode and the tape ends,
A shut-off operation bottle (6I) is pressed and driven in one direction of the arrow in FIG. 3 by a shut-off lever set v, which will be described later, and the shut-off operation is automatically performed.

That is, by pressing the shut-off operation bin IIti+ in the direction of the arrow j in FIG. 3, the lock plate uIJ is rotated in the direction of the arrow j in FIG. The lock at the forward movement position of IJ L'/(-Ml) is M
It is removed. Then this play button lever Uυ and play button (
71 are integrally moved back in the direction of the arrow in FIG. 3 by means of a return spring. Along with this, the head substrate f51 is returned by the spring 11b in the direction of the arrow in FIG. 2, and is moved back in the direction of the pinch roller (II) by the pinch roller lever (2). As a result, the pinch roller tl+ is separated from the capstan (91), and the running of the magnetic tape +81 is automatically stopped, resulting in a stop mode.

By the way, as shown in FIG. 4, the pinch roller (11 is made of a rubber roller or the like and is fixed to the outer periphery of a cylindrical roller width axis 4 made of synthetic resin or the like, and the roller center It is rotatably inserted into the outer periphery of the roller support shaft +31 by @.Also, a rotating shaft portion (231) with a smaller diameter than this is integrally provided at the lower end of this roller center 111)l (2a. The shut-off lever (2JJ) is attached to the outer periphery of this rotating shaft (c).

Next, as shown in FIGS. 5 and 6, the shutoff lever () is made of synthetic resin or the like.

A disc 341 and an arm t25+ extending to one side from the lower surface of the disc 341 are integrally provided with each other. And disk c! A wedge-shaped elongated hole □□□ that tapers in one direction [the direction opposite to the arm (241)] is provided in the center of the hole.The minimum width W1 on the tapered side of this wedge-shaped elongated hole Ca is The maximum weight IW2 on the opposite side of and 7 is Wl < DI, W
The relationship z≧D1 is established. Further, the end (26a) of the wedge-shaped elongated hole (maximum +1) on the W2 side is formed in a semicircular arc shape. Further, at the tip of the arm holder, a driven pin auxiliary unit extending downward is integrally provided in a vertical shape, and one side of the middle part of the arm (251 in the longitudinal direction) is provided with the aforementioned shutoff. A driving protrusion Q81 for driving the operation bin aυ is integrally provided.

And this shut-off lever is a rotating egg; part (to)
is inserted into the outer periphery of the wedge-shaped elongated hole C261, and this shut-off lever circle is inserted in the direction perpendicular to the axis P direction of the pinch roller 111 (see Fig. 4), which is the longitudinal direction of the wedge-shaped elongated hole (C). (arrows l and m directions in figure 6)
It is movable in the direction of the arrows n and 0 in FIG.

Next, a spring mounting pin Gl is attached to the pinch roller lever 121 at a position near the pinch roller 11+ L41!
A 71, and the biasing spring mark Ivi can be seen on this spring attachment bottle (c). This biasing spring is composed of a return coil spring, and is inserted into the outer periphery of the spring attachment pin C21 by means of a coil portion (30a). One end (3ob) of this biasing spring is a U-groove 311 formed on the -side surface of the disk (to) of the shut-off lever 121).
The disk (24J) is engaged from a direction parallel to the PA line direction, and the other end (3 (IcJ) is engaged with the spring locking portion (321 (see In the U-groove G3D, a first contact portion G331 and a second contact portion c14I are provided at one end of the biasing spring arm (30bJ) with an interval in the longitudinal direction.

Next, the driving body referred to in the present invention is a cam gear (3D). This cam gear 6n is formed of synthetic resin or the like, and has a circular recess 61 on its upper surface inside the outer gear C181. are arranged on the same axis.

In this circular recess q, a first cam (4
A second cam (J) is provided at a peripheral position, and a driving protrusion (421) is provided at an intermediate position between these cams.

The outer circumferential surface of the first cam 14I is formed into an eccentric cam surface (40aJ), and the second cam 141 has a gentle mountain shape protruding from the inner circumferential surface (39a) of the circular recess 69 toward the center. It has a cam surface C41a). And the driving protrusion (421 is the eccentric cam surface (40a) of the first cam +41
) is placed outside the minimum radius 111 of the drive protrusion (421), but the position of the drive protrusion (421) is
Outside the radius of rotation of the maximum radius R2 of the eccentric cam surface (40a) of the cam (fourth), and beyond the radius of rotation of the chevron-shaped protrusion of the second cam (fourth angular cam surface (41a) @ (41b)) is also inside.

Note that the second cam (411 is a driving protrusion (M2 for 4)
It has a phase angle θ of O3. Also, cam gear 1; (7
] is rotated in the direction of arrow r in FIG. 6, as will be described later.

The drive surface (42aJ) of the drive protrusion (42) on the front side in the rotation direction is formed in a plane perpendicular to the rotation direction (arrow r direction).However, the center of the circular recess of the drive surface (42s) A small protrusion (44j) is integrally provided at the end of the side. Also, the width W3 of the gap 11JI is larger than the diameter D2 of the driven pin (271) of the shut-off lever GD. .

Next, a cam gear 6D having one or more structures is rotatably supported on the outer periphery of a gear support 1tblη fixed at a position near the capstan +91 at the lower part of the chassis aa. At the bottom of the chassis, remove the capstan (9).
A drive gear (48I) is fixed to the bottom end of the lid.

The associated gear +4al and the outer peripheral gear link of the cam gear 13η are interlocked by an intermediate gear (49). Also, intermediate gear! 4! 11 is composed of upper and lower gears, and its upper gear (49a) is engaged with a drive gear decoy, and its lower gear (49b) is engaged with an outer gear (g).

Therefore, as described above, the rotation of the capstan (9) by the motor in the direction of arrow e in FIG. 6 causes the cam gear 0'f) to rotate at low speed in the direction of arrow r in FIG. 6 via the intermediate gear (49). It is configured to be driven by 5.

Therefore, the shutoff lens <-(2n driven bin (27j is the opening (50
1 (see Fig. 4) and extends below the chassis (12), and its driven pin +271 is inserted into the cam gear C
) is inserted from above into the circular recess G3 sickle. And shutoff lever CI! As described above, it is moved to the forward movement position shown in FIG. 6 by the forward movement of the pinch roller 11+ to the forward movement position, and the pinch roller il+
5, so that by the return movement to the forward movement position, the movement is moved to the return movement position shown by the imaginary line.

The shutoff mechanism of the present invention is constructed as described above and operates as follows.

First, FIG. 7A shows the recording or reproducing mode, in which the shut-off lever (21J) and the pinch rollers fi+ are moved in the direction of arrow d and retracted to the forward position.

At this time, one end (30b) of the biasing spring is in contact with the first J concubine 1413+ of the shutoff lever [211, and the pressing force of the one end (30bJ) in the direction of the arrow S causes the shutoff to be shut off. The lever QD is biased to slide in the direction of arrow 1.The shutoff lever 1211, which is biased to slide in the direction of arrow !, is inserted into the wedge-shaped elongated hole #2e.
It is crimped onto the outer circumferential surface (23a) of the rotating shaft portion (c) of the rope center shaft (221) by a biting action (wedge effect).

On the other hand, in recording or playback mode, as shown in Figure 2,
The rotation of the capstan (9) in the direction of the arrow e causes the magnetic tube (8) to run at a constant speed in the direction of the arrow f, and the pinch roller (II) rotates in the direction of the arrow g. The central axis is rotated in the direction of arrow g in FIG. 7A.

Therefore, in the recording or playback mode, the wedge-shaped elongated hole G61
Due to the biting action of t2, the shutoff lever 2D is urged to rotate in the direction of arrow n in FIG. The driven pin (271) at the tip of the capstan (271) is constantly pressed against the eccentric cam surface (40a) of the first cam +41 of the cam gear C in the direction of the arrow. 1: Arrow r in Figure 7A
It is rotated at low speed in the direction.

Therefore, in the recording or reproducing mode, the cam gear C rotates in the direction of the arrow r, as shown by the solid line and the imaginary line in FIG. 7A.
The driven bin 01 of the shut-off lever Qυ is followed by the circumferential surface (40a) of the first cam +41 of 37 (1) and moved forward in the arrow and U direction, and the shut-off lever (-t2υ is connected to the rotating shaft part ( Rotate the bales in the direction of arrows n and 0 around c) (
rocking motion). At this time, the driven pin 1271 of the shut-off lever QD is connected to the drive protrusion (421
Since the driving protrusion (4z) escapes through the gap (4'5 portion), the driving protrusion (4z) does not come into contact with the driven bottle (271).

Next, in recording or playback mode, the tape ends, etc.
When the running of the magnetic tape 18+ is stopped, the rotation of the pinch roller 11+ is also stopped accordingly. Note that the capstan (9) continues to rotate.

Then, from the moment the pinch roller +I+ stops rotating, the cam gear C7) completes one rotation.

A shutoff operation is performed.

That is, at the moment when the rotation of the pinch roller 11+ stops, the rotation biasing force of the shutoff lever +21 in the direction of arrow n in FIG. 7A disappears.

Next, the maximum diameter R2 of the first cam (the eccentric cam surface (40a) of the , the driven bin (27) is pushed out in the direction of arrow U and is stopped within the pivoting trajectory of the jumping protrusion (four forces).

Next, as shown by the solid line in FIG. 7B, the cam gear G37 is rotated in the direction of arrow r, and its four drive protrusions (42a) abut against the driven pin CI force.

Press the driven bin (27J) in the direction of arrow r.

Then, as shown by the imaginary line in FIG. 7B, the shut-off repercussion D slides in the direction of the arrow m against the biasing spring q, and the drive protrusion t281 of the arm CI!51 moves against the lock plate (11!). is moved to the front position of the shut-off operation bin 1I61.Then, by sliding the shut-off lever (211-) in the direction of the arrow m, the outer circumferential surface of the rotating shaft portion QJ of the wedge-shaped elongated hole CJ61 (23aJ When the action is released, the semicircular arc-shaped end (26a) on the maximum width Wz side of the wedge-shaped elongated hole □□□ has a rotational capacity of 1 part (c).
The shutoff lever 1211 is brought into contact with the negative side surface of the outer surface (23a), and further sliding of the shutoff lever 1211 in the direction of the arrow m is restricted.

-t, and at the moment when the sliding movement of the shutoff lever f211 in the direction of the arrow m is restricted (the state shown by the virtual line in Fig. 7C), it is rotated in the direction of the arrow r in Fig. 7C to drive the cam gear 07). The driven bottle (271) is rotated in the direction of arrow r by the vertical surface (42a) of the protrusion (421) as shown by the solid line in FIG. 7C.
The small protrusion (4) provided on the driven bin (2a)
2'D has a 13ft inner gap from the drive surface C42a)! l
This prevents the driven bin c! 71 is reliably rotated in the direction of arrow r.

As the driven bin [271] rotates in the direction of the arrow r, the shut-off lever Qυ, which is integrated with the driven bin [271], rotates in the direction of the arrow n as shown by the solid line in FIG. and the drive protrusion t2 of the arm I25)
Al shuts off! The 1rl1 operating pin flil is suppressed and driven in the direction of the arrow i in FIG. 3, and the above-mentioned shut-off operation is automatically performed.

As mentioned above, when the shutoff operation is performed, the pinch roller (11) is moved back to the backward movement position at that moment, so the shutoff lever (2N MORS 7B) is moved back from the forward movement position shown by the imaginary line in Figure 7B. It is moved in the direction of the arrow and is returned to the return position shown by the solid line.At this time, the driven bin c!n slides outward from the driving protrusion (47J's driving lJ1 surface (42a)), and this time It comes into contact with the inner peripheral surface (39a) of the circular four-part example of the cam gear +371.

Next, the operation when the play button (7) is pressed again after the above-mentioned reset-off operation, which is generally called a tampering operation, will be explained with reference to FIG. 7E.

That is, if the play button (71) is pressed, the pinch roller (1
1 and the shut-off lever (2D) is moved again in the direction of arrow d to the forward position.
Pinch roller (1) is rotated.

- 10,000, the six cam gears continue to rotate in the direction of the arrow R, and the chevron-shaped cam surface (41a) of the second cam t4D pushes the driven gear D from the position of the imaginary line to the position of the solid line in the direction of the arrow V. Then, the drive protrusion (421) is stopped again within the rotation locus.Then, the drive protrusion (42) rotating in the direction of the arrow r moves to the driven pin f27 as shown in the imaginary line.
1 again, and the above-mentioned shutoff operation is performed again.

By the way, the shutoff mechanism of the present invention does not perform the shutoff operation in the fast forwarding or rewinding mode, and in the fast forwarding or rewinding mode, the driven pin 1271 of the shutoff lever Qυ is driven by the cam gear C37). It is configured so that it does not engage with the protrusion (421).

Therefore, in fast forward or rewind mode, the drive protrusion (421
The operation of avoiding engagement of the driven pin (271) will be explained with reference to FIGS. 8A and 8B.

First, in the recording or reproducing mode, the shutoff lever 1211 is moved forward to the forward position, as shown by the imaginary line in FIG. 8A. And at this time, one part of the case (3
0bJ is the first contact part C of the shutoff lever '-1211
33, and the shutoff lever (2D) is urged to slide in the direction of the arrow ! by the pressing force of the one end (3ob) in the direction of the arrow S.

Next, in the fast forward or rewind mode, the shutoff lever C?
I) has been moved to the backward movement position. At this time, as the pinch rollers 1 to 11 relative to the cam gear 6D move in the direction of the arrow, the shut-off lever (the driven pin surface of the two lines is on the inner circumferential surface t39m of the circular portion G31 of the cam gear 1371). When the shut-off lever (2υ
is the outer periphery of the rotating shaft portion Q31 of the roller center axis Q21 and is indicated by the arrow n.
rotated in the direction.

As a result of the above, in fast forward or rewind mode, the biasing spring (
7) -Rn (3 (Ib)) is in contact with the second contact portion 134+ of the shut-off lever 12II, and due to the pressing force in the direction of the arrow y of one end (311bJ), the shut-off lever 1211 is rotated. The rotational force in the direction of arrow 0 about the shaft C3 is 9 degrees.This rotational force causes the circular recess 13 of the pull-out IIru pin (2D is the cam gear T37) of the shut-off lever (21).
The inner circumferential surface (39a) of 1 is constantly pressed from the direction of arrow X.

As described above, in the fast forward or rewind mode, the driven pin Cl171 of the shutoff lever t211 is connected to the cam gear G.
(Engagement with the drive protrusion 71 (4) is avoided.

Even in fast forward or rewind mode, the capstan (
9) is rotated in the direction of arrow e, the cam gear 13
'0 is also rotated in the direction of arrow r. For this reason, as shown by the solid line in Fig. 8B, when the second cam (4υ) passes.

Its chevron-shaped cam surface (driven pin +27 by 41aJ)
is moved in the direction of arrow V and pushed out into the rotation locus of the drive protrusion (42). However, after passing the second cam (41), the shut-off lever Qυ (as shown by the imaginary line in Fig. sB) is immediately moved in the direction of arrow 0 by the spring force of spring ■ The driven pin 12η is immediately moved in the direction of the arrow X.

It is immediately avoided to the outside of the rotation locus of the drive protrusion (421).

As a result, in this fast forward or rewind mode.

The driven pin 0D is never accidentally engaged with the driving protrusion, and the driven pin 1271 is reliably avoided from the driving protrusion.

[Application Examples] Although the embodiments of the present invention have been described above, various effective applications are possible based on the technical idea of the present invention.

For example, the present invention is not limited to the data recorder shown in the embodiment, but can also be applied to a VTR.

Further, in the embodiment, a pinch roller is used as the rotary body referred to in the present invention, but the present invention can be applied to various other rotary bodies.

【Effect of the invention〕

As described above, the present invention provides a reciprocating rotary body which is moved forward to a forward position in recording or playback mode and returned to a backward position in fast forward or rewind mode, and this rotary body is moved forward and backward. 5, so that the shut-off lever is rotated once as the tape runs and stops when the tape stops running. The rotating body is attached to be slidable and rotatable around its axis, and when the rotating body is moved to the forward position, it comes into contact with the first still contacting part of the shutoff L/bar and shuts off the shutoff L/bar. When the off-lever is slid in one direction in the sliding direction and the rotating body is in the backward movement position RK, the second shut-off lever is
A biasing spring is provided which contacts the abutting portion and biases the shut-off lever to rotate in a direction opposite to the rotational direction of the rotating body, and in recording or reproducing mode, the shut-off lever is slidably biased. This shut-off lever is frictionally engaged with the rotating body and biased to rotate in the rotational direction of the rotating body,
When the tape running in this recording or playback mode is stopped and the rotating bias of the shut-off lever by the rotary body is released, the shut-off lever is engaged with the drive body and the drive body Rotate the shut-off lever in a predetermined direction to perform the desired shut-off operation, and in fast forward or rewind mode, rotate the shut-off lever in the opposite direction to the rotational direction of the rotating body. This is a shutoff mechanism configured to avoid engagement of the shutoff lever with the drive body by causing the shutoff lever to engage with the drive body.

Therefore, according to the present invention, there is provided a mechanical system configured to perform a shutoff operation from a trap such as a tape end in a recording or playback mode, and to prevent a shutoff operation from a trap such as a tape end in a fast forward or rewind mode. Although it is a shut-off mechanism, at that time.

The reciprocating motion of the rotating body is used to switch the contact state of the biasing spring against the shut-off lever, so that one biasing spring is in frictional engagement with the rotating body in recording or playback mode. It is configured so that it can be used as a biasing spring to cause the shutter to move, and can also be used as a switching spring to avoid engagement of the shutoff lever with the drive body in fast forward or rewind mode.

As a result, according to the present invention, a special mechanism for avoiding engagement of the shutoff lever with the °C driver in fast forward or rewind mode can be omitted.

The mechanism is very simple and can be obtained at a very low cost. Furthermore, in the fast forward or rewind mode, there is no risk of the shutoff lever engaging the drive member on the wrong side and generating significant frictional noise or impact, so the reliability is very high.

[Brief explanation of drawings]

The drawing shows an embodiment of a shutoff mechanism in which the present invention is applied to a power nut type compact tape recorder,
Fig. 1 is an overall perspective view, Fig. 2 is a plan view, Fig. 3 is a side view, Fig. 4 is a vertical sectional view, and Fig. 5 is a view F showing the shut-off lever and cam gear. FIG. 6 is an open plan view, and FIGS. 7A to 7E, 8A, and 8B are plan views for explaining the shutoff operation and related operations. Also, the reference numeral i used in the drawings. (11・・・・・・・・・Pinch day-ra(5)・・・
・・・・・・Head board (7)・・・・・・・・・
Play button (81...Magnetic tape (9)...
・・・・・・Capstan aυ・・・・・・・Lock plate (+61・・・・・・・Shutoff operation pin t
2U......Shutoff lever Q21...
・・・・・・Roller center axis (c)・・・・・・・・・
・Rotating shaft part (26)・・・・・・Wedge-shaped long hole (2n...
・・・・・・・・・Driven bin (to)・・・・・・・・・
・Drive protrusion 0α・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ to drive the protrusion 0α・・・・・・・・・・・・・・・・・・・ to bias spring link ・・・・ 1st contact part (341 ・・・ 2nd contact part 3D...
......Cam gear 6 scratches......Circular recess (41......1st cam (41J...2nd cam) Cam (4shi...
...It is a driving protrusion. Agent: Katsutsune, Toshiki Sugiura

Claims (1)

[Claims] A reciprocating rotating body is provided, which is moved forward to a forward position in recording or playback mode and back to a backward position in fast forward or rewind mode, and this rotating body is in a state of being moved forward to the forward position. The shut-off lever is configured to rotate as the tape runs and to stop rotating when the tape stops running, and a shut-off lever is slidable on the rotating body in a direction orthogonal to the axis of the rotary body, and The rotating body is rotatably attached to the circumference, and when the rotating body is moved to the working position, it comes into contact with the first contact portion of the shut-off lever and slides the shut-off lever in one direction of the sliding direction. When the rotating body is in the dynamically biased state and is moved back to the return position, it is brought into contact with the second contact portion of the shut-off lever, and the shut-off lever is rotated in the opposite direction to the rotational direction of the rotating body. In the recording or playback mode, the shut-off lever slides and urges the shut-off lever to frictionally engage with the rotary body and rotate in the direction of rotation of the rotary body. When the tape running in the recording or playback mode is stopped and the rotational bias of the shut-off lever by the rotary body is released, the shut-off lever is engaged with the drive body to close the shut-off lever. The driver drives the shut-off lever in a predetermined direction to perform the desired shirt-off operation.In fast forward or rewind mode, the shut-off lever is moved in the direction of rotation of the rotating body. A shutoff mechanism configured to avoid engagement of the shutoff lever with the drive body by biasing rotation in the opposite direction.