JPH0337151Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to the transmission mechanism of a tape recorder, and is particularly suitable for reversing the running direction and changing the running speed of a small cassette tape. It is about the mechanism.

[Background technology and its problems]

Generally, tape recorders are equipped with a transmission mechanism for normal playback, rewinding, fast forwarding, etc., but some tape recorders are also equipped with a reciprocating playback head to perform reverse playback.

However, the transmission mechanism of such a tape recorder capable of reverse playback transmits the rotation at normal tape speed (playback speed) and the rotation at high tape speed during fast forwarding and rewinding through intermediate gears with different reduction ratios. Since the power is transmitted to the reel shafts on the supply side and the take-up side, switching the lever becomes complicated and it is difficult to make it compact.

There is also a device that uses two drive belts to simplify the switching mechanism, but a two-stage belt mechanism increases the thickness of the tape deck and restricts miniaturization.

[Purpose of invention]

This idea was made in view of the above situation, and by arranging the transmission mechanism so that the switching mechanism is concentrated approximately in the middle of the two flywheels and the intermediate gear, the operating mode of the tape recorder can be changed. In addition to making it easy to switch, the transmission mechanism can be made smaller.

[Summary of the idea]

In order to achieve the above object, this invention arranges two flywheels and an intermediate pulley to form an almost triangular shape, connects them with one belt, drives them by a motor, and connects them to the supply reel shaft. Fast-forwarding and rewinding are performed by alternately coupling relay gears that swing in mesh with the drive gears of the take-up reel shafts to either one of the two flywheels. By connecting one of the two transmission gears connected to the intermediate pulley and being decelerated, a normal regeneration mode and a reverse regeneration mode are established.

Therefore, since the transmission switching mechanism can be located approximately in the center of the area where the belt is hung, the transmission mechanism can be made compact and a compact tape recorder can be realized.

〔Example〕

FIG. 1 is a plan view showing the main parts of the transmission mechanism of the tape recorder of this invention, and the part indicated by the dashed line shows the switching mechanism.

In this figure, 1 is the rotation axis of the drive motor M;
2 and 3 are first and second flywheels fixed to two capstan shafts that run the tape during normal playback and reverse playback;
3a and 3a are gears connected to the flywheel shaft. 4 is an intermediate pulley, and these are connected by one belt 5.

Further, 6 and 7 are take-up gears and supply gears connected to the take-up reel shaft and the supply reel shaft, respectively, and 8 and 9 are the first and second gears in constant meshing with the take-up gear 6 and supply gear 7, respectively. Second relay lever 10, 11
The first and second relay gears are pivotally supported by the first and second relay gears. Note that in the reverse playback mechanism, there is no need to distinguish between take-up and supply, but the settings are set as above.

12, 13, and 14 are reduction gears that reduce the rotation of the intermediate pulley 4, and the final reduction gear 14 is a first reduction gear that meshes with the second relay gear 9 via a slip mechanism.
The drive gear 15 is coaxially connected to the drive gear 15 of the drive gear 15 . The first drive gear 15 is further coupled to a second drive gear 16 that is loosely fitted to the shaft of the intermediate pulley 4.

As will be described later, the first and second drive gears 15 and 16 mesh with the first and second relay gears 8 and 9, which are moved by switching levers 17 and 18, so that the normal reproduction mode and reverse mode can be selected. Form playback mode.

The switching levers 17 and 18 are each rotatably supported at a point P, and have protrusions 17a and 18a inserted into the long holes 10a and 11a of the first and second relay levers 10 and 11 at one end. , and pins 17b and 18b which abut against the concave and convex pieces of the switching plate 19 are formed at the other end. Note that C indicates the area of the cassette.

Since the transmission mechanism of the tape recorder of this invention has the above-mentioned configuration, the drive motor M
When the rotating shaft 1 of is rotating clockwise, the first,
The second flyholes 2 and 3 and the intermediate pulley 4 rotate in the direction of the arrow, and the take-up gear 6 and supply gear 7 alternately rotate in the direction of the arrow depending on the operation mode of the tape recorder to perform normal playback. It has four drive modes: mode (FWD), reverse play mode (REV), fast forward mode (F/F), and rewind mode (REW).

Each operating mode of the tape recorder will be explained below using state diagrams shown in FIGS. 2a, b, c, and d.

FIG. 2a shows the normal reproduction mode, in which the switching plate 19 is moved to the right by an operating mechanism (not shown), and the pin 17b of the switching lever 17 is depressed into the recess of the switching plate 19. Therefore, the first relay lever 10 is biased clockwise, and the first relay gear 8 is biased toward the second drive gear 1.
6, the take-up gear 6 rotates in the direction of the arrow shown in the figure and winds up the tape in a normal playback state. At this time, the other switching lever 18 is placed in the neutral position, so the second relay gear 9 is in a free state.

In this state, when the switching plate 19 is moved to the left by one step, the pin 18b of the switching lever 18 rides on the convex part of the switching plate 19, and the second relay lever 11 is moved clockwise. Rotate to. Then, the second relay gear 9 meshes with the gear 3a of the second flywheel 3 and rotates the supply gear 7 at high speed as shown by the arrow, thereby setting the rewind mode.

At this time, the first relay gear 8 is in a free state because the switching lever 17 is in the neutral position, and the take-up gear 6 is pulled by the tape and rotates.

Next, when the switching plate 19 is further moved one step to the left from this state, the pin 17b of the switching lever 17 rides on the convex part of the switching plate 19, as shown in FIG. Rotate counterclockwise. Then, the first relay gear 8 meshes with the gear 2a of the first flywheel 2, so the take-up gear 6 rotates at high speed and enters a fast-forwarding state. At this time, the second relay gear 9 is in a free state.

Further, when the switching plate 19 is on the left side, the pin 18b of the switching lever 18 falls into the recess of the switching plate 19, as shown in FIG. 2d. In this case, since the second relay lever 11 rotates counterclockwise, contrary to the case shown in FIG. 2a, the second relay gear 9 meshes with the first drive gear 15. Therefore, the supply gear 7 rotates as shown by the arrow, and enters the reverse regeneration state. Note that the first relay gear 8 is placed in the neutral position and becomes free.

Above are the four operation modes (FWD, REW, F/
The movement of the first and second relay gears 8 and 9 in FREV) has been explained, but in the fast forward and rewind modes where the tape is running at high speed, a mechanism (not shown) is used to prevent pinching, as in a normal tape recorder. The roller is controlled to be separated from the capstan, and in normal regeneration (FWD), the pinch roller is in pressure contact only with the capstan shaft of the first flywheel 2, and in reverse regeneration (REV), the pinch roller is in pressure contact with the capstan shaft of the second flywheel 3. Needless to say, the pinch roller is pressed against only the shaft.

Note that in order to rotate the first and second relay levers 10 and 11, the two switching levers 17 and 18 and the switching plate 19 are moved. , 11 can be rotated using other link mechanisms or cam mechanisms.

Further, a reduction gear (not shown) for transmitting the rotational force of the first drive gear 15 may be meshed with a gear for operating the auto-reverse mechanism.

[Effect of idea]

As explained above, the drive mechanism of the tape recorder of this invention reverses the running direction of the tape and changes the tape speed using the take-up reel shaft.
This is performed by swinging control of first and second relay gears that are loosely fitted to the supply reel shaft and supported by two relay levers that swing from side to side.
Since the driving force transmitted to the two relay gears is obtained from the rotational force of the two flywheels arranged in a nearly triangular shape and the intermediate pulley, switching control can be performed almost at the center of the cassette area. , the transmission mechanism fits within the occupied area of the cassette;
It can be made extremely compact.

Furthermore, since the driving force is supplied from the motor shaft by a single belt, the thickness of the transmission mechanism is also extremely thin, which has the advantage that the entire tape recorder can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a gear arrangement diagram showing the transmission mechanism of the tape recorder of this invention, and FIGS. 2 a to 2 d are explanatory diagrams showing gear movements in various operating modes. In the figure, 2 and 3 are the first and second flywheels,
4 is an intermediate pulley, 5 is a belt, 6 is a take-up gear, 7 is a supply gear, 8 and 9 are first and second relay gears, and 10 and 11 are first and second relay levers.

Claims (1)

[Claims for Utility Model Registration] First and second flywheels that rotate in opposite directions, an intermediate pulley located between a take-up reel shaft and a supply reel shaft, and the first and second flywheels. a motor that rotationally drives a wheel and the intermediate pulley in a fixed direction via a single belt; first and second relay levers that rotate about the respective reel shafts as fulcrums; and the first , first and second relay gears that are pivotally supported by a second relay lever and mesh with the respective reel shafts; and a first relay gear that is coupled to the shafts of the first and second flywheels, respectively. , a second gear, and first and second drive gears coupled to the intermediate pulley; A tape recorder comprising a single switching mechanism that controls the rotational positions of the first and second relay levers so that the first and second relay gears are selectively engaged with each other. transmission mechanism.