JPS642275Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tape running switching device, and particularly in a two-capstan type tape running switching device.
The present invention relates to a tape running switching device that reduces the load when moving a head board forward.

A reverse type tape recorder that does not require changing operations of tape reels or tape cassettes is provided with a tape running switching device for switching the running direction of the magnetic tape from forward (normal) to reverse. As this tape running switching device, for example, a two-capstan type switching device is known. This two-capstan type switching device selectively presses either one of a pair of pinch rollers against a pair of capstan shafts that rotate in opposite directions, allowing the magnetic tape to run forward (normal run) or reverse. I'm trying to get the running done.

By the way, in the conventional two-capstan type switching device, a pair of pressure springs are bridged between the pair of pinch roller levers and the head board, and a stopper is installed to selectively restrict the rotation of the pair of pinch roller levers. is provided, and with this stopper restricting the rotation of one of the pinch roller levers, by moving the head board forward, only the other pinch roller lever is pulled while pulling the pair of pressure springs together. was rotated to selectively press the pinch roller of the other pinch roller lever onto the capstan. Therefore, when the head board is moved forward, the other compression spring is pulled very strongly, and this applies a strong pullback force to the head board in the forward direction, putting strain on the drive system of the head board. was occurring.

The present invention was devised in order to correct the above-mentioned defects, and its purpose is to provide a tape running switch that allows the head board to move smoothly forward with a relatively small force in a two-capstan type tape running switching device. The goal is to provide equipment.

An embodiment in which the present invention is applied to a cassette tape deck will be described below with reference to the drawings.

As shown in Figures 1 and 2, the mechanical chassis 2 of the cassette tape deck 1 includes a pair of left and right capstan shafts 3, 4, and a reel drive shaft 2.
Cassette positioning pieces 27 and 28 for positioning the tape cassettes 5 and 26 and the tape cassette 29 are provided. A pair of flywheels 5, 6 are attached to the pair of capstan shafts 3, 4, as shown in FIG. It is being spanned. When the drive pulley 7 is driven in the direction of arrow a in FIG. 3, one flywheel 5 is driven in the direction of arrow b, and the other flywheel 6 is driven in the direction of arrow c.

A drive gear 9 is integrally attached to the flywheel 5 as shown in FIG. This driving gear 9 meshes with a driven gear 10, so that the driven gear 10 is always driven in the direction of arrow d in FIG. Further, a pinion gear 11 is integrally attached to the driven gear 10, and a partially toothed gear 1 is attached to the side of the pinion gear 11.
2 and 13 are arranged. Above pinion gear 1
1 is normally a partially toothed gear 12, 1 as shown in FIG.
The toothless gears 12 and 13 are in a stopped state, respectively. However, magnets 18 and 19 are attached to the rotating shafts 16 and 17 of the partially toothed gears 12 and 13, respectively, and by exciting the electromagnetic magnet 20 or 21, the partially toothed gear 12 or 13 moves in the direction of the arrow e in FIG. or pinion gear 1 by rotating in the direction of arrow f.
It is designed to mesh with 1. A stopper pin 24 is implanted in one of the toothless gears 12, and when the toothless gear 12 rotates once, the stopper pin 24 comes into contact with a stopper portion 42 of a lock lever 38, which will be described later, to stop the toothless gear 12. Rotation is now prevented. Missing tooth gear 12,1
The rotating shafts 16 and 17 of No. 3 also have cams 22 and 23.
These cams 22 and 23 drive a head board drive lever 37 and a sliding plate 48, respectively, which will be described later.

As shown in FIGS. 1 and 2, the mechanical chassis 2 is provided with a head substrate 30 that is vertically slidable. On this head board 30 is a 4-track magnetic head 31 that serves both recording and playback.
A pair of erasing heads 32 and 33 are installed, respectively, so that both forward recording and playback and reverse recording and playback can be performed. Note that a tension spring 34 is provided between the head board 30 and the mechanical chassis 2.
is constantly urged downward by this tension spring 34.

A pressed portion 35 is formed on the head substrate 30 as shown in FIG. On the other hand, a head board drive lever 37 is rotatably supported on a fixed support shaft 36 fixed to the mechanical chassis 2. One end of the head board drive lever 37 constitutes a pressing portion 37a facing the pressed portion 35, and the other end forms a pressed portion 37a extending to the side of the cam 22.
7b. When the partially toothed gear 12 rotates in the direction of arrow e in FIG. 4, the cam 22 presses the pressed portion 37b, and the head board 30 moves upward in FIG. 4 via the head board drive lever 37. It is composed of

The fixed support shaft 36 also includes a lock lever 38.
is rotatably supported. This lock lever 38 has an iron piece 39, a U-shaped notch 40, and a stopper 42, and is always urged to rotate slightly counterclockwise in FIG. 4 by a tension spring 44. When the electromagnetic magnet 20 is excited, the iron piece 39 is attracted to the electromagnetic magnet 20, and the lock lever 38 is urged to rotate strongly counterclockwise in FIG. 4. Further, when the head board 30 moves forward in this state, the lock pin 41 fixed to the head board 30 and the notch 40 click into engagement.

As shown in FIG. 4, a selection lever 46 is attached to the head board 30 and is rotatable about a fulcrum pin 45. This selection lever 46 is always urged to rotate counterclockwise in FIG. 4 by a tension spring 47, and has a pressed portion 46a at its upper end.
However, there is also an L-shaped engaging portion 4 at the bottom end.
6b are formed respectively. On the other hand, a sliding plate 48 is attached to the mechanical chassis 2 and is capable of sliding in the left-right direction.A pressing plate 48 is bent into an L-shape at one end of the sliding plate 48 so as to face the pressed portion 46a. A portion 48a is formed, and a pressed portion 48b bent in an L shape so as to protrude to the side of the cam 23 is formed at the other end. When the partially toothed gear 13 rotates in the direction of arrow f in FIG.
3 presses the pressed portion 46b, and the selection lever 46 is rotated clockwise in FIG. 4 via the sliding plate 48.

A pair of pinch roller levers 52 and 53 are provided on both left and right sides of the head board 30, as shown in FIGS. 1 and 2. The pair of pinch roller levers 52 and 53 are rotatably supported by a pair of left and right fixed support shafts 54 and 55 implanted in the mechanical chassis 2. A pair of pinch rollers 56 and 57 are rotatably supported by a pair of roller support pins 58 and 59 attached to the tips of pinch roller levers 52 and 53, respectively. The pair of pinch roller levers 52 and 53 have operating arms 60 and 61, respectively. On the other hand, as shown in FIG. 4, a pair of left and right sliding plates 62 and 63 are attached to the mechanical chassis 2 so as to be slidable in the left and right direction. The pair of spring fastening portions 64 and 65 of the pair of sliding plates 62 and 63 and the operating arm portion 6
A pair of spring fastening portions 7 provided slightly closer to the fixed support shafts 54 and 55 than the tip portions 68 and 69 of 0 and 61.
1 and 72 are connected to each other by a pair of compression springs 66 and 67, respectively. In addition, a pair of sliding plates 6
2 and 63 are provided with a pair of pressing portions 73 and 74, and the pair of pressing portions 73 and 74 are normally pressed against the pair of tip portions 68 and 6 of the pair of operating arms 60 and 61.
9 and are in contact with each other. Therefore, one sliding plate 6
2 is constantly biased in the direction of arrow j in FIG. 4 by a compression spring 66, and the pinch roller lever 52 is constantly biased to rotate counterclockwise in FIG. Also,
The other sliding plate 63 is always biased in the direction of arrow k in FIG. 4 by the compression spring 67, and the pinch roller lever 53 is biased to rotate clockwise in FIG.

As shown in FIG. 4, the mechanical chassis 2 is provided with a pair of left and right L-shaped pivot levers 78 and 79. The pair of rotating levers 78 and 79 are connected to a pair of fulcrum pins 80 fixed to the mechanical chassis 2,
L-shaped engaged portions 82 and 83 are provided at one end of each of the levers 81 so as to be rotatable, and are engageable with the engaging portion 46b of the selection lever 46. When the head board 30 moves forward while the engaging portion 46b of the selection lever 46 is engaged with either of the engaged portions 82, 83, the rotating lever 78 or 79 rotates forward in conjunction with this. It's becoming like that. Further, the other end portions of the pair of rotating levers 78 and 79 form a pair of pressing portions 84 and 85.
4 and 85 are constantly pressed into contact with a pair of pressed portions 86 and 87 provided on the pair of sliding plates 62 and 63. In addition, a pair of left and right stopper pins 88, 89 are implanted in the mechanical chassis 2, and a pair of rotation levers 7 are connected by the pair of stoppers 88, 89.
8 and 79 are held in the return rotation position shown in FIG.

The tape running switching device is constructed as described above, and forward running is achieved by exciting the electromagnetic magnet 20.
Reverse running is accomplished by simultaneously exciting 0 and 21. Below, this operating situation will first be explained for forward running, and then for reverse running.

Forward running is done using electromagnetic magnet 2 as mentioned above.
This is done by exciting 0. That is, when the electromagnetic magnet 20 is excited as shown in FIG. 4, a rotating force in the direction of arrow e in FIG. 4 acts on the magnet 18, causing the partially toothed gear 12 to rotate in the same direction. Then, the partially toothed gear 12 meshes with the pinion gear 11, which is constantly rotating in the direction of arrow d in FIG. 4, and rotates once.
When the partially toothed gear 12 rotates once, the pressed portion 37b of the head board drive lever 37 is pressed by the cam 22, and the head board drive lever 37 rotates clockwise in FIG. Then, the pressed portion 35 of the head board 30 is pressed against the pressed portion 37 of the head board drive lever 37.
4, and the head substrate 30 moves upward in FIG. 4 against the tension spring 34. When the head board 30 moves forward as shown in FIG. It engages with the mating portion 82 and rotates the rotating lever 78 clockwise as shown in FIG. Then the sliding plate 62
The pressed portion 86 of is pressed by the pressing portion 84 of the rotating lever 78, and the sliding plate 62 moves in the direction of the arrow g as shown in FIG.
move in a direction. For this reason, the pinch roller lever 5
2 is urged to rotate clockwise in FIG. 5 by the compression spring 66, the pinch roller 56 is pressed against the capstan shaft 3, and forward running is achieved. It should be noted that while the forward running (same goes for reverse running), the electromagnetic magnet 20 continues to be excited and constantly attracts the iron piece 39. Therefore, the lock lever 38 is always rotated counterclockwise as shown in FIG. 4, and when the head board 30 moves forward in this state, the locked pin 41 moves into the notch 40 of the lock lever 38 as shown in FIG. 5, the head board 30 is locked in the forward position shown in FIG. When the head board 30 is locked in this manner, the stopped pin 24 of the partially toothed gear 12 comes into contact with the stopper portion 42 of the lock lever 38, and the rotation of the partially toothed gear 12 is stopped.

In this way, the pinch roller 56
0 is crimped onto the capstan shaft 3 in conjunction with the forward movement of the head board 30. At this time, only the tension spring 34 and one crimping spring 66 are acting as a load for the forward movement of the head board 30; The spring 67 does not become a load for the forward movement of the head board 30. Therefore, the head board 30 can be smoothly moved forward with the same force as in the case of an ordinary tape deck (a tape deck capable of only forward running).
The load on the drive system of the head board 30 can be significantly reduced (about half that of a normal tape deck).

Next, reverse running will be explained. In this case, electromagnets 20 and 21 are simultaneously excited. Then, rotating forces in the directions of arrows e and f in FIG. 4 act simultaneously on the magnets 18 and 19, causing the partially toothed gears 12 and 13 to rotate in the same direction.
Therefore, the toothless gears 12 and 13 are connected to the pinion gear 11.
They mesh with each other and rotate once each. At this time, the cam 22
As is clear from comparing the shapes of
Before pressing b, the cam 23 presses the pressed portion 48b of the sliding plate 48. Therefore, first, the sliding plate 48 moves forward in the direction of arrow h in FIG. 4, and its pressing portion 48a presses the pressed portion 46a of the selection lever 46. Then, the selection lever 46 moves against the tension spring 47 and moves to the fourth position.
Rotate clockwise in the figure to select the position in reverse driving mode. Thereafter, the head board 30 moves forward as shown in FIG. 6 in the same manner as in the case of forward travel described above, and at this time, the engaging portion 46b of the selection lever 46 engages with the engaged portion 83 of the rotary lever 79. Then, the rotary lever 79 is rotated counterclockwise as shown in FIG. Then, the pressed portion 87 of the sliding plate 63 is pressed by the pressing portion 85 of the rotating lever 79, and the sliding plate 63 moves forward in the direction of arrow i as shown in FIG. Therefore, the pinch roller lever 53 is rotated counterclockwise in FIG. 6 by the pressure spring 67, and the pinch roller 57 is pressed against the capstan shaft 4, thereby achieving reverse travel.

Even in this reverse running, only the tension spring 34 and one pressure spring 67 are the load for the forward movement of the head board 30, and the other pressure spring 66 is not a load for the forward movement of the head board 30. . Therefore, the head board 30 can be smoothly moved forward as in the case of forward travel, and the load on the drive system of the head board 30 can be significantly reduced.

Next, the operating conditions when changing from forward running mode to stop mode will be explained. The stop mode is achieved by de-energizing the electromagnetic magnet 20. That is, when the electromagnetic magnet 20 is de-energized, the taper portion 4 of the notch 40
The locking lever 38 rotates clockwise in FIG. 5 due to the pressing force of the locked pin 41 against the locking pin 41, and the engagement between the locked pin 41 and the notch 40 is released.
Then, the head board 30 is pulled by the tension spring 34 and moves downward in FIG. be done. Therefore, the rotary lever 78 becomes free, and the pressed portion 86 of the sliding plate 62
is released. Therefore, the pinch roller lever 52 is rotated counterclockwise as shown in FIG. 4 due to the moment difference generated by the pressure spring 66, and the pinch roller 56 is separated from the capstan shaft 3. Further, the sliding plate 62 is pulled by a tension spring 66 and moves back as shown in FIG. The operating conditions when changing from the reverse running mode to the stop mode are exactly the same as those described above, so a description thereof will be omitted.

Although one embodiment of the present invention has been described above, the present invention is not limited to the structure shown in the above embodiment and can be modified in various ways. For example, in the above embodiment, the head board 30 is connected to a pair of rotating levers 7.
Although the selection lever 46 is used as an engagement member that selectively engages the elements 8 and 79, the selection lever 46 may be of any type as long as it can selectively engage the elements 8 and 79. An engaging member may be employed. Further, in the above embodiment, a pair of pinch roller levers 5
2, 53 and a pair of rotating levers 78, 79, a pair of compression springs 66, 67 and a pair of sliding plates 62,
63, respectively, a pair of pinch roller levers 52, 53 and a pair of rotating levers 78, 79.
It is also possible to directly connect them with a pair of compression springs 66 and 67, respectively.

As described above, the present invention selectively engages the engaging member provided on the head board with one of the pair of engaged members, and then moves the head board forward to move one pinch roller to the other. Since the tape running switching device is crimped to the capstan shaft, the crimping spring connected to the other engaged member does not act as a load on the forward movement of the head board. Therefore, the head board can be smoothly moved forward with a relatively small force, and the load on the drive system of the head board can be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a cassette-type tape deck. Fig. 1 is a perspective view of the main body of the tape deck, Fig. 2 is a front view of the same, and Fig. 3 shows a pair of capstan shafts. 4 is a front view showing the drive mechanism of a pair of partially toothed gears, FIG. 4 is a front view in stop mode with the mechanical chassis omitted from FIG. 2, FIG. 5 is an explanatory diagram for explaining the forward running mode, and FIG. 6 FIG. 2 is an explanatory diagram for explaining a reverse driving mode. Also, in the symbols used in the drawings, 3, 4...
... Capstan shaft, 21 ... Electromagnetic magnet, 2
3...Cam, 46...Selection lever, 46b...Engaging portion, 47...Tension spring, 48...Sliding plate, 5
2,53...pinch roller lever, 56,57...
...Pinch roller, 62, 63...Sliding plate, 66,
67...Crimp spring, 78, 79...Rotating lever,
82, 83... engaged parts.

Claims (1)

[Claims for Utility Model Registration] Forward running and reverse running of a magnetic tape by selectively pressing one of a pair of pinch rollers against a pair of capstan shafts rotating in opposite directions. In the tape running switching device, a pair of moving members rotatably supporting and movable the pair of pinch rollers, b a pair of pressure springs each having one end connected to the pair of moving members, c the above. a pair of engaged members respectively connected to the other ends of the pair of compression springs, d an engaging member provided on a reciprocally movable head board and capable of selectively engaging with the pair of engaged members; , e control means for selectively controlling the engagement of the engaging member with the pair of engaged members, wherein the engaging member and one of the engaged members are controlled by the control means. 1. A tape running switching device characterized in that, after the two pinch rollers are engaged with each other, the head board is moved forward to press the one pinch roller to the one capstan shaft.