JP2734082B2 - Power transmission mechanism in tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A power transmission mechanism in a tape recorder of the present invention will be described according to the following items.

A. Industrial application fields B. Summary of the invention C. Prior art D. Problems to be solved by the invention E. Means to solve the problems F. Embodiments [FIGS. 1 to 5] a. Video Tape recorder [Fig. 1] b. Drive system [Figs. 1 to 5] c. Switching means [Figs. 2 to 5] d. Operation [Fig. 5] e. Figure] f. Function f-1. Reproduction mode, reverse reproduction mode [Fig. 5 (C)] f-2. FF / REW mode [Fig. 5 (B)] f-3. High-speed REW mode [Fig. 5] (A)] G. Effects of the Invention (A. Industrial Application Field) The present invention relates to a power transmission mechanism in a novel tape recorder. In detail, in the power transmission mechanism of the tape recorder equipped with a common drive source for the drive of the capstan and the drive of the reel base, by devising the arrangement of the gears of the power transmission gear train and the interposition position of the torque limiter, etc. It is an object of the present invention to provide a novel power transmission mechanism in a tape recorder in which a switching operation to each mode can be performed by a common slide lever, and the mechanism can be simplified.

(B. Summary of the Invention) In the power transmission mechanism of the tape recorder of the present invention, the drive source for driving the capstan and the drive source for driving the reel stand are common, and the drive source and the drive source are connected to each other and rotated. Power transmission mechanism in a tape recorder having a power transmission gear train for transmitting power and a reel stand positioned at the end of the power transmission gear train, wherein a mode requiring a torque limiter, such as a reproduction mode, and a fast forward Or, a mode for feeding or rewinding the magnetic tape at a higher speed than the playback mode, such as a rewind mode, and a mode for feeding or rewinding the magnetic tape at a higher speed than the fast-forward or rewind mode, such as a high-speed fast-forward or rewind mode. In order to form a power transmission gear train, switch to a gear train with a different reduction ratio in the power transmission gear train and an insertion / removal mechanism for inserting and removing the torque limiter in the power transmission gear train And a gear train switching means for performing these operations, and operating the insertion / removal mechanism and / or the gear train switching means by a common slide lever, thereby forming a large number of modes with a small number of parts and a simple mechanism. It is something that can be done.

(C. Prior Art) In recent years, in a video tape recorder, a motor for driving a capstan shaft and a motor for driving two reel bases have been shared in response to a request for simplification of the mechanism.

Such a video tape recorder runs the magnetic tape at a constant speed and winds the magnetic tape in a mode for reading or recording a signal recorded on the magnetic tape such as a reproduction mode and a reverse reproduction mode. It is necessary to change the rotation speed of the reel base in accordance with the winding amount of the magnetic tape around the reel base.Therefore, it is necessary to insert a torque limiter in a power transmission gear train from the capstan motor to the reel base, Further, in a mode such as a fast-forward or rewind mode in which a magnetic tape signal is not read or recorded and a magnetic tape is fed or returned, it is not necessary to insert the torque limiter.

Therefore, the power transmission mechanism of such a video tape recorder is provided with an insertion / removal mechanism for inserting / removing a torque limiter from / to a power transmission gear train, and the insertion / removal mechanism operates in a predetermined mode. .

(D. Problems to be Solved by the Invention) However, the fast-forward or rewind of the video tape recorder as described above is usually performed with the magnetic tape returned in the unloading direction.
Although the running speed of the magnetic tape can be increased, the loading operation of the magnetic tape must be performed when the mode is switched from the fast-forward or rewind mode to the reproduction mode or the reverse reproduction mode, or when the mode is reversed. However, there has been a problem that such mode switching cannot be performed quickly.

Further, it is conceivable that the fast-forward or rewind mode is performed in a state where the magnetic tape is loaded. However, from the viewpoint of protection of the magnetic tape, the running speed of the magnetic tape cannot be increased while the tape is still loaded. There is a problem.

(E. Means for Solving the Problems) In order to solve the above-described problems, a power transmission mechanism in the tape recorder of the present invention includes an insertion / removal mechanism for inserting / removing a torque limiter from / to a power transmission gear train, and a power transmission mechanism. Gear train switching means for switching between gear trains having different reduction ratios in the gear train, a first mode in which a torque limiter is inserted in the power transmission gear train, and no torque limiter is inserted in the power transmission gear train, and The second mode in which a gear train with a low reduction ratio of the power transmission gear train is selected, and the gear train with no gear inserted in the power transmission gear train and a high reduction ratio in the power transmission gear train are selected. The third mode and the third mode are formed by operating the insertion / removal mechanism and / or gear train switching means by a common slide lever.

Therefore, according to the power transmission mechanism in the tape recorder of the present invention, while the drive source for driving the capstan shaft and the drive source for driving the two reel bases are common, the magnetic tape is fed or returned while the magnetic tape is loaded. And a high-speed fast-forward or high-speed rewind mode in which the magnetic tape is returned in the unloading direction, and a high-speed fast-rewind mode in which the magnetic tape is returned in the unloading direction. The transmission gear train can be realized with less complexity and fewer components.

(F. Embodiment) [FIGS. 1 to 5] Hereinafter, the power transmission mechanism of the tape recorder of the present invention will be described in detail with reference to the illustrated embodiment applied to a video tape recorder.

(A. Video Tape Recorder) [FIG. 1] 1 is a video tape recorder, 2 is its mechanical chassis, which is on the upper surface side of the mechanical chassis 2 and in front of its center (in FIG. (The front side, the upward direction is the rear side, the rightward direction is the right side, and the leftward direction is the left side. In the following description, this direction is used when indicating the direction.) An S-side reel base 3 and a T-side reel base 4 are rotatably disposed relative to the mechanical chassis 2 at left and right positions, respectively, and the reel bases 3 and 4 are respectively provided with reel base gears 3a,
4a is formed.

Reference numeral 5 denotes a capstan motor disposed behind the T-side reel base 4 and on the lower surface side of the mechanical chassis 2, and an output shaft of the capstan motor 5 penetrates the mechanical chassis 2 and protrudes to the upper surface side. , And a capstan shaft 6.

Reference numeral 7 denotes a pinch roller disposed on the upper surface side of the mechanical chassis 2 so as to face the capstan shaft 6. The pinch roller 7 sets a tape when the video tape recorder 1 is in a mode for reproducing an image signal or the like. The capstan shaft 6 is pressed against the capstan shaft 6 in order to make it run at high speed.

Numeral 8 is a drive pulley below the capstan motor 5 and fixed to its output shaft.

9 is a tape cassette, which is a video tape recorder 1
When the tape 10 is mounted at a predetermined position, the tape 10 is pulled out and wound around the rotary head drum 11 at a predetermined winding angle, and a predetermined tape path is formed by various tape guides.

(B. Drive System) [FIGS. 1 to 5] Reference numeral 12 denotes a lower surface side of the mechanical chassis 2, which is located below the S-side reel base 3 and the T-side reel base 4. The sub-plate 12 is attached with an appropriate interval between the sub-plate 12 and various gears.

Reference numeral 13 denotes a driven pulley, which is a lower surface of the mechanical chassis 2 and is rotatably supported slightly below the position where the T-side reel base 4 is located.
On the upper surface of the spur gear 14 is slightly smaller in diameter than the driven pulley 13.
Are integrally formed.

The driven pulley 13 and the driving pulley 8 are located at substantially the same height in the vertical direction, and an endless belt 15 is stretched between the driven pulley 13 and the driving pulley 8.

(C. Switching means) [FIGS. 2 to 5] Reference numeral 16 denotes a support shaft which is planted at the right end of the sub-plate 12 so as to protrude upward. Mode switching gear that can move in the axial direction, that is, in the vertical direction.
The mode switching gear 17 is formed of a spur gear, and is always meshed with the spur gear 14.

Further, a coil spring 18 externally fitted to the support shaft 16 is interposed between the sub-plate 12 and the mode switching gear 17, and an upward moving force is urged on the mode switching gear 17.

Reference numeral 19 denotes a pressing body that holds the mode switching gear 17 at a position below the support shaft 16 against the elastic force of the coil spring 18,
The pressing body 19 has a flat U shape opened to the left when viewed from above, and has two arms 19a, 19a, and a support piece 20 erected near the mode switching gear 17 of the sub-plate 12, An arm piece 19c, 19c protruding rightward at the center of the base 19b is bifurcated at the center of the base 19b at the upper end of the base 20. The distal end portion is a pressing portion 19c ', 19c' that presses the vicinity of the rotation center of the mode switching gear 17 downward, and furthermore, the lower edge of the arm 19a located at the rear has a rear end. A pressed portion 19d which extends toward and is pressed by a slider member described later is integrally formed, extends downward from the left edge of the pressed portion 19d, and protrudes downward through a window formed in the sub-plate 12. A spring hook 19e is formed integrally.

The pressing body 19 has its spring hook piece 19e and the spring hook piece 19e.
The tension spring 21 is stretched between the left side of the sub-plate 12 and the spring hooking piece 12a protruding from the lower surface of the sub-plate 12, so that the pressing portions 19c 'and 19c' move in the direction of moving downward. When a rotating force is applied, the mode switching gear 17 is pressed downward, and when the pressed portion 19d is pressed rightward by a slider member described later, the pressing body 19 is counterclockwise viewed from the front. It is rotated in the rotation direction, and the pressing portions 19c ', 19c'
Is released, and the mode switching gear 17 is moved upward by the elastic force of the coil spring 18.

The mode switching gear 17 is pressed downward by the pressing body 19, and the position held on the base end side of the support shaft 16 is referred to as a lower position, and the downward pressing by the pressing body 19 is released. The position pressed upward by the elastic force of the coil spring 18 and held at the upper end side of the support shaft 16 is referred to as an upper position.

Reference numeral 22 denotes a support shaft planted at substantially the center of the sub-plate 12 so as to protrude upward. The drive shaft body 23 is rotatably supported on the support shaft 22.

The drive-side gear body 23 rotates with a lower spur gear 24, a rotating sleeve 25 protruding upward from the center of the upper surface of the lower spur gear 24, and an upper spur gear 26 integrally formed at the upper end of the rotating sleeve 25. Limiter gear 27 rotatably fitted to sleeve body 25
A compression coil spring 28 is interposed between the limiter gear 27 and the upper spur gear 26;
A felt member (not shown) is interposed between the lower spur gear 27 and the lower spur gear 24, and the drive-side gear body 23 is formed by integrating the limiter gear 27 with the lower spur gear 24 and the upper spur gear 26 when the load is light. As the load increases, the limiter gear 27, the lower spur gear 24 and the upper spur gear 26 slide, and both gears 27 and 24
26 and 26.

The upper spur gear 26 of the drive side gear body 23 is formed to be thick, and most of the upper spur gear 26 is a window 2a formed in the mechanical chassis 2.
Is located on its upper surface side.

The lower spur gear 24 is meshed with the mode switching gear 17 when the mode switching gear 17 is at the lower position, and the limiter gear 27 is meshed with the mode switching gear 17 when the mode switching gear 17 is at the upper position. It has been like that.

Reference numeral 29 denotes a spindle planted at the left end of the sub-plate 22 so as to protrude upward. The tip of the spindle 29 extends through a window 2b formed on the left side of the window 2a of the mechanical chassis 2 and on its upper surface side. It is protruding.

Reference numeral 30 denotes a pressing member which has a U-shape opened downward as viewed from the side and moves an intermediate gear described later up and down,
The push-up member 30 includes a support piece 3 having its both arm pieces 30a, 30a erected before and after the left side of the drive side gear body 23 of the sub-plate 12.
A push-up piece 30c, which is rotatably supported by an axis extending in the front-rear direction on the base 31 and 31 with a shaft extending in the front-rear direction, and protrudes leftward at a position slightly closer to the front side than the center of the base 30b, is integrally formed. The push-up piece 30c has a long hole 3 extending leftward.
0d is formed, and the support 29 is positioned so as to pass through the long hole 30d.

The push-up member 30 has a compression coil spring 32 interposed between the lower surface of the push-up piece 30c and the sub-plate 12, thereby imparting a clockwise turning force to the push-up member 30 when viewed from the front. .

Further, the one arm piece 30 located behind the push-up member 30
The rotation is prevented by the stopper piece 30e projecting rightward from the lower right edge of the a being in contact with the upper surface of the sub-plate 22, and the upper right edge of the one arm piece 30a is stair-stepped. A pressed portion 30f which is pressed by a slider member described later is formed.

Further, the upper end of the support shaft 29 is freely supported by a support plate 33 attached to the upper surface of the mechanical chassis 2 at an appropriate distance therefrom.

In addition, an intermediate gear, which will be described later, is supported on the support shaft 29 above the push-up piece 30c so as to be rotatable and vertically movable,
In a state where the intermediate gear is rotated clockwise as viewed from the front by the elastic force of the coil spring 32, the intermediate gear is
The intermediate gear is held at an upper position (hereinafter, referred to as a “push-up position”) by c, and the intermediate gear is moved downward (hereinafter, referred to as “upward position”) while being rotated counterclockwise by a slider member described later. (Referred to as “down position”).

Reference numeral 34 denotes a lower surface side of the mechanical chassis 2, between the S-side reel base 3 and the T-side reel base 4,
A slider member which is located behind a line connecting the respective rotation centers of the sliders 4 and 4 and is slidably supported by the mechanical chassis 2 in the left-right direction. Connecting protrusion 34e is integrally formed, the left edge of which is a first pressing portion 34b that presses the pressed portion 30f of the push-up member 30, and a lower portion is located at a position slightly leftward from the center thereof. A pressing piece 34c protruding toward is formed integrally, and a pressed portion 19d of the pressing body 19 is formed at a lower end edge of the pressing piece 34c.
A second pressing portion 34d is provided to protrude from the second pressing portion 34d.

The distance between the first pressing portion 34b and the second pressing portion 34d is determined by the pressed portion 19d and the push-up member 3 when the pressing body 19 is pressing the mode switching gear 17 to the lower position.
0 is substantially the same as or slightly larger than the gap between the coil 30 and the pressed portion 30f in a state where the later-described intermediate gear is pushed up to the push-up position by the coil spring 32.

Reference numeral 35 denotes a lower surface side of the mechanical chassis 2 and a cam gear rotatably supported below the rear side of the T-side reel base 4. The cam gear 35 has a wheel gear portion 35a attached to the lower surface of the mechanical chassis 2. And a worm 37 fixed to the output shaft of the set mode setting motor 36, and a predetermined cam groove 35b is formed on the upper surface thereof.

38 is the lower surface side of the mechanical chassis 2,
A swing lever rotatably supported by a support shaft 39 protruding at a position slightly to the left of 35. The swing lever 38 has a rear end supported by the support shaft 39, A long hole 38a extending in the longitudinal direction is formed at the moving end, and a copying pin protruding downward at a position slightly closer to the rotation fulcrum than the center.
38b are integrally formed.

The sliding lever 38 has its copying pin 38b slidably engaged with the cam groove 35b of the cam gear 35, and the connecting projection 34a of the slider member 34 is slidably engaged with the long hole 38a. Have been combined.

(D. Operation) [FIG. 5] However, when the mode setting motor 36 is driven, the cam gear 35 is rotated via the worm 37, and the copying pin 38b of the swing lever 38 is moved along the cam groove 35b. In accordance with the shape, the swing lever 38 is rotated, and further,
The rotation of the swing lever 38 causes the slider member 34 to slide in the left-right direction.

Then, the slider member 34 does not press the pressed portion 30f of the push-up member 30 or the pressed portion 19d of the pressing body 19 by any of the first pressing portion 34b and the second pressing portion 34d (fifth embodiment). When the slider member 34 is moved to the left with the neutral position (hereinafter referred to as “B position”), the first pressing portion 34b is pressed by the pressed portion 3 of the lifting member 30 (see FIG. 2B).
0f is pressed to the left (see FIG. 5 (A)) (hereinafter referred to as “A position”), and the push-up member 30 is rotated counterclockwise as viewed from the front. When the slider member 34 is moved rightward from the B position, the second pressing portion 34d is pressed by the pressed portion 19d of the pressing body 19.
Is pressed rightward (see FIG. 5 (C)).
Say "C position". ), And the pressing body
19 is rotated counterclockwise when viewed from the front and its pressing part
19c 'and 19c' are in a state where the downward pressing of the mode switching gear 17 is released.

Reference numeral 40 denotes an intermediate gear rotatably and vertically movably supported by a portion of the support shaft 29 implanted on the sub-plate 12 projecting upward from the mechanical chassis 2. A downwardly projecting sleeve body 41 is formed integrally with the portion, and the lower end surface of the sleeve body 41 is placed on the peripheral portion of the long hole 30d of the push-up piece 30c of the push-up member 30, and the A compression coil spring 42 externally fitted to the support shaft 29 is interposed between the upper surface of the gear 40 and the lower surface of the support plate 33, and presses the intermediate gear 40 downward.

The elastic force of the compression coil spring 42 is set to be weaker than the elastic force of the compression coil spring 32 fitted to the lower part of the support shaft 29, and the intermediate gear 40 is not pressed by the slider member 34 (B position or (C position) at the push-up position.

In addition, the intermediate gear 40 is an upper flat gear of the drive side gear body 23 regardless of whether the intermediate gear 40 is in the push-up position or the lowered position.
26 is always engaged.

Reference numeral 43 denotes a oscillating lever rotatably supported by the support shaft 22 of the driving-side gear body 23. The oscillating lever 43 is located above the upper spur gear 26 and has an upper spur gear at its swinging end. A pendulum gear 44 meshed with 26 is rotatably supported.

That is, the support shaft 45 is vertically provided at the swing end of the swing lever 43,
A pendulum gear 44 is rotatably supported by the support shaft 45,
The lower end of the support shaft 45 protrudes toward the lower surface of the mechanical chassis 2 through a horizontally long rectangular window 2c formed substantially at the center between the two reel stands 3 and 4 of the mechanical chassis 2.

Reference numerals 46 and 47 denote relay gears which are separately and always meshed with the reel base gears 3a and 4a of the reel bases 3 and 4, respectively. These relay gears 46 and 47 sandwich the pendulum gear 44, and When the gear 44 is located substantially at the center, which of the relay gears 46 and 47
It is rotatably supported on the upper surface of the mechanical chassis 2 at such a position as to engage with the biased relay gear 46 or 47 when it is deflected to either one without engaging with the other.

On the upper surface of the S-side relay gear 46, a flat gear 48 having a smaller diameter than that of the intermediate gear 46 is integrally formed concentrically.
When 40 is in its lowered position, it will engage with it.

(E. Swing Prevention Means) [FIG. 2] Reference numeral 49 denotes a swing prevention means for preventing the swing motion of the pendulum gear 44. The swing prevention means 49 includes a motor for driving the same and a motor. It comprises a cam gear for converting the rotational movement of the motor into a predetermined rotation, a swing link, and a slider for converting the rotation of the swing link into a linear movement and pressing the pendulum gear 44.

Reference numeral 50 denotes a cam gear formed of a spur gear. A cam groove 50a is formed on one surface of the cam gear. The cam gear 50 is rotatable on the lower surface of the mechanical chassis 2 so that the cam groove 50a faces the mechanical chassis 2. It is supported and rotated by the mode setting motor 36 via a gear train (not shown).

Reference numeral 51 denotes a swinging link having a substantially L-shape. The bent portion is a lower surface of the mechanical chassis 2 and is rotatably supported at a position near the cam gear 50 so as to be rotatable with respect to the mechanical chassis 2. The arm 51a can swing freely in a direction parallel to the surface of the arm, and its short arm 51a extends obliquely rightward and backward from the center of the swing, and its tip end is positioned between the cam gear 50 and the mechanical chassis 2. Further, the longer arm 51b is positioned so as to extend substantially forward from the swing center.

Further, a pin 51c protruding downward is integrally formed at the distal end of the shorter arm 51a of the swing link 51, and the pin 51c is slidably engaged with the cam groove 50a of the cam gear 50, and is long. A connecting pin 51d projecting downward is integrally formed at an end of the arm 51b, and the connecting pin 51d is engaged with a slider described later.

The cam gear 50 is rotated by a mode setting motor 36 through a gear train (not shown), and the pin 51c of the shorter arm 51a of the swing link 51 engaged with the cam groove 50a follows the cam groove 50a. As a result, the swing link 51 is swung, and the link pin 51d of the longer arm 51b is swung substantially in the left-right direction.

Reference numeral 52 denotes a slider made of a synthetic resin, which is slidably supported in the left-right direction on the lower surface near the front edge of the mechanical chassis 2, and formed at one end with a slightly long slot 52a in the width direction. A connection pin 51d provided on a long arm 51b of the swing link 51 is slidably engaged with the long hole 52a, and
The other end of the slider 52 is the rectangular window 2c of the mechanical chassis 2.
2 and the other end thereof protrudes rearward.
The two pressing pieces 53 are integrally formed, and the two pressing pieces 53
The lower end portion of the support shaft 45 of the pendulum gear 44 is located between and.

The slider 52 is slid in the left and right direction when the swing link 51 is swung by the mode setting motor 36, and the pendulum gear 44 is moved by the two pressing pieces 53 and 53.
Is moved to control the swinging motion of the pendulum gear 44.

(F. Action) In the video tape recorder 1 described above, the mode setting motor 36 is driven by selecting each mode, and the cam gear 35 or 50 is rotated to form a predetermined mode. I have.

(F-1. Reproduction mode, reverse reproduction mode) [FIG. 5 (C)] When the reproduction mode or the reverse reproduction mode is selected, the slider member 34 is controlled by the cam gear 35 so as to move from the B position to the C position. , The second pressing portion 34d
Presses the pressed portion 19d of the pressing body 19 rightward, and the pressing portion 1
9c 'and 19c' are moved upward, and accordingly, the mode switching gear 17 is moved upward by the elastic force of the compression coil spring 18. Then, the mode switching gear 17 moved to the upper position meshes with the limiter gear 27 of the drive side gear body 23.

At the same time, in the case of the reproduction mode, the capstan motor 5 is rotated counterclockwise to feed the tape 10 sandwiched between the capstan shaft 6 and the pinch roller 7 to the T-side reel base 4 side. Together with the drive pulley 8-belt
15-Followed pulley 13-Spur gear 14-Mode switching gear 17-Limiter gear 27-Upper spur gear 26 of drive side gear body 23 and its rotation are transmitted, and upper spur gear 26 is rotated in the counterclockwise direction, The lever 43 is swung toward the T-side reel base 4 and
The side relay gear 47 and the pendulum gear 44 mesh with each other, rotate the T-side reel base 4 clockwise, and wind up the tape 10 sent out by the pinch roller 7 and the capstan shaft 6. .

In the reproduction mode and the reverse reproduction mode, the pressing pieces 53 and 53 of the slider 52 do not press the support shaft 45 of the pendulum gear 44, and the pendulum gear 44 moves in a predetermined direction in response to the rotation direction of the drive side gear body 23. Swings in the direction of.

In the case of the reverse reproduction mode, the capstan motor 5
Are rotated in the reverse direction, that is, clockwise, to feed the tape 10 to the S-side reel base 3 side, and the respective gears rotate in the opposite direction to those in the above-described reproduction mode, so that the pendulum gear 44
Swings toward the S-side reel base 3 to rotate the S-side reel base 3 in the direction of winding on the tape 10.

(F-2. FF / REW mode) [FIG. 5 (B)] When the FF / REW mode is selected, the pinch roller 7 moves away from the capstan shaft 6 and the tape path remains unchanged, that is, the tape is moved. With the pinch roller 7 separated from the capstan shaft 6 in the loaded state, the cam gear is moved so that the slider member 34 is located at the B position.
Controlled by 35, the first pressing portion 34b and the second pressing portion 34d do not press the corresponding push-up member 30, the pressed portion 30f of the pressing body 19, and the pressed portion 19d, respectively. Thereby, the mode switching gear 17 is held at the lower position, and the intermediate gear 40 is held at the push-up position.

The mode switching gear 17 meshes with the lower spur gear 24 of the driving gear body 23, and the first gear train is formed by meshing of the upper spur gear 26, the pendulum gear 44, and the relay gear 46 or 47 of the driving gear body 23. And the reel base gear 3a or 4a is rotated in the winding direction of the tape 10, so that the FF / REW mode is formed.

(F-3. High-speed REW mode) [FIG. 5 (A)] When the high-speed REW mode is selected, the slider member 34 is set to A in a state where the tape 10 is unloaded, that is, returned to the inside of the tape cassette 9. It is controlled by the cam gear 35 to move to the position, and the first pressing portion 34b presses the pressed portion 30f of the push-up member 30 to the left,
The push-up member 30 is rotated counterclockwise as viewed from the front,
The push-up piece 30c is moved downward. Then, the intermediate gear 40 placed on the push-up piece 30c of the push-up member 30 moves the push-up piece 30c of the push-up member 30 downward and moves the compression coil spring 42.
The intermediate gear 40 moved to the lowering position by the resilient force of the intermediate gear 40 and moved to the lowering position is engaged with the flat gear 48 integrally formed with the S-side relay gear 46.

Thus, the upper spur gear 26-intermediate gear of the drive side gear body 23
A second gear train is formed by the 40-spur gear 48-S-side relay gear 46, and the S-side reel base gear 3a is rotated in the winding direction of the tape 10, so that the high-speed REW mode is formed. .

At this time, the slider 52 is supported by the support shaft 45 of the pendulum gear 44.
Is controlled by the cam gear 50 so as to be held at the neutral position by the pressing piece 53. This is to prevent the swing lever 43 from rotating and the pendulum gear 44 from engaging with the S-side relay gear 46 following the rotation of the drive-side gear body 23.

In the high-speed REW mode, as described above, the S-side relay gear 46 of the second gear train from the drive-side gear body 23 to the S-side relay gear 46, and thereby the small-diameter flat gear 48 Are formed integrally, and the small-diameter spur gear 48 is rotated by the intermediate gear 40, so that the reduction gear ratio is lower than that of the first gear train in the FF / REW mode. REW
Even when the rotation speed of the capstan motor 5 is the same in each of the mode and the high-speed REW mode, the S-side reel base 3 can be rotated at a higher speed in the high-speed REW mode.

(G. Effects of the Invention) As is clear from the above description, the power transmission mechanism in the tape recorder of the present invention has a common drive source for driving the capstan and a drive source for driving the reel base. A power transmission mechanism in a tape recorder comprising a drive source, a power transmission gear train connected to the drive source and transmitting the rotation thereof, and a reel stand positioned at an end of the power transmission gear train, comprising: a power transmission gear train; A first mode in which a torque limiter is inserted into and removed from the power transmission gear train, and gear train switching means for switching between gear trains having different reduction ratios in the power transmission gear train. The second mode in which the torque limiter is not inserted into the power transmission gear train and a gear train having a low reduction ratio of the power transmission gear train is selected, and the torque limiter is inserted into the power transmission gear train. The third mode in which the gear train having a high reduction ratio of the power transmission gear train is selected without operating the insertion / removal mechanism and / or the gear train switching means using a common slide lever. It is characterized by the following.

Therefore, according to the power transmission mechanism in the tape recorder of the present invention, while the drive source for driving the capstan shaft and the drive source for driving the two reel bases are common, the magnetic tape is fed or returned while the magnetic tape is loaded. And a high-speed fast-forward or high-speed rewind mode in which the magnetic tape is returned in the unloading direction, and a high-speed fast-rewind mode in which the magnetic tape is returned in the unloading direction. The transmission gear train can be realized with less complexity and fewer components.

In the above description, the tape was unloaded in the high-speed REW mode.However, it is not necessary to completely unload the tape. High-speed FF with a path that does not cause damage
/ REW mode may be used.

Further, in the above-described embodiment, an example in which only the high-speed REW mode is formed is described. The good thing is, of course.

In addition, the structures shown in the above embodiments are merely examples of the embodiments of the present invention, and do not mean that the technical scope of the present invention is limitedly interpreted. Various changes can be made without departing from the spirit of the present invention.

[Brief description of the drawings]

1 to 5 show an embodiment in which the power transmission mechanism of the tape recorder of the present invention is applied to a video tape recorder. FIG. 1 is a schematic plan view of the whole, and FIG. FIG. 3 is an enlarged cross-sectional view taken along the line III-III of FIG. 1, FIG. 4 is an exploded perspective view of a main part viewed obliquely from the rear, and FIGS. 5 (A) to (C) are main parts. 2A is a schematic side view, FIG. 2A shows an A position, FIG. 2B shows a B position, and FIG. 1C shows a C position. DESCRIPTION OF SYMBOLS 1 ... tape recorder, 3, 4 ... reel base, 5 ... drive source, 19, 34, 35, 36 ... insertion / removal mechanism, 23, 44, 46, 47 ... gear train, 23, 40, 46, 48 ... gear train, 27, 28 ... torque limiter, 30, 34, 35, 36 ... gear train switching means, 34 ... slide lever

Claims (1)

(57) [Claims] A drive source for driving a capstan and a drive source for driving a reel base are common, and the drive source, a power transmission gear train connected to the drive source and transmitting the rotation thereof, and the power transmission gear A power transmission mechanism in a tape recorder having a reel stand positioned at the end of a row, comprising: an insertion / removal mechanism for inserting / removing a torque limiter from / to a power transmission gear row; and a gear row having a different reduction ratio in the power transmission gear row. A first mode in which a torque limiter is inserted into the power transmission gear train, and a reduction ratio of the power transmission gear train without inserting the torque limiter into the power transmission gear train. A second mode in which a lower gear train is selected, and a torque limiter is not inserted in the power transmission gear train, and
Third gear train with a high reduction ratio of the power transmission gear train is selected
A power transmission mechanism in a tape recorder, wherein the mode is selected by operating the insertion / removal mechanism and / or gear train switching means by a common slide lever.