JPS5858736B2 - tape drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape drive device such as a reel drive type magnetic recording/reproducing device.

Conventionally, in a reel drive device in which a single centrally located capstan simultaneously drives two reels on the supply side and take-up side to run the tape, a constant tension is applied to the tape. It is known that in order to run the tape stably, the pressure force between the reel on the tape winding side and the capstan must be greater than the pressure force between the reel on the tape supply side and the capstan. There is.

Therefore, when the tape is run back and forth, it is necessary to change the pressure force of the reel depending on the running direction of the tape.

Therefore, as a device for changing the pressing force of the reel against the capstan, there has conventionally been a device as shown in FIGS. 1 and 2.

In FIG. 1, 51 is a chassis, 52 is a capstan,
53.54 is the reel, 55 is the tape, 56 is the head, 5
7.58 is an arm, and the arms 57 and 58 are each rotatable about a fulcrum 59.60.

6L62 is a belt with a spring 66.67 and an arm 57.58 between pulleys 63, 64 and 65, respectively.
It is strung through.

Further, the pulley 65 is fixed to a capstan shaft 68 and rotates together with the capstan shaft 68.

A spring 69 is drawn between the arms 57, 58 and presses the reels 53, 54 against the capstan 52.

When the capstan 52 is stopped, the rail 53.5
40 are the same pressing force, but when the left reel 53 rotates in the direction shown by arrow C, the pressing force of the left reel 53 decreases because the belt 61 is pulled in the direction of the arrow by the frictional force between it and the pulley 65, and vice versa. The pressing force of the right reel increases as the belt 62 is pulled in the direction of arrow E.

In other words, the pressure of the reel 54 on the take-up side is the same as that of the reel 5 on the supply side.
It becomes larger than the pressure bonding force of 3.

Similarly, when the capstan 52 rotates in the opposite direction of the arrow C, the pressing force of the reel 53 becomes greater than the pressing force of the reel 54.

In conventional devices such as those mentioned above, the pressure difference is obtained by the frictional force between the belt and the pulley, so the pressure difference easily changes due to fluctuations in temperature, humidity, etc., and the capstan shaft is subject to excessive load. Therefore, it is necessary to use a motor with a large torque to drive the capstan.

The present invention provides a tape drive device that does not have the above-mentioned drawbacks and can reliably switch the pressure force.

Examples according to the present invention will be described in detail below.

FIG. 3 is a schematic diagram of a magnetic recording/reproducing apparatus equipped with the tape drive device of the present invention.

Here, 1 is the chassis and 2 is the capstan.

An elastic body 3 made of rubber or the like is pasted on its outer periphery, and is fixed to a capstan shaft 4.

The capstan shaft 4 is rotatably supported by a bearing 5 fixed to the chassis 1.

Further, a flywheel 6 is fixed to the capstan shaft 4 on the back side of the chassis 1, and is driven by a pulley 8 attached to a motor 7 via a capstan belt 9.

10 is a reel A, and 11 is a reel B, which are fixed to reel shafts 16 and 17 that are rotatably supported by bearings 14 and 15 fixed to slide plates 12 and 13, respectively.

Slide plates 12 and 13 are rails 18, 19, and 2, respectively.
It is arranged so that it can slide smoothly from side to side along the steel balls 22, 22, .

In addition, as will be detailed later, reel A10 and reel B1
A spring 30 is installed to press 1 onto the capstan 2.

3L32, 33, 34 are tape guides, 35.36.3
7 is the head.

The tape 38 is wound around the reel A10 and the capstan 2
At the crimping point 39 between the tape roll and the tape guide 31, the reel B passes through the hook guide and the head in order.
Reel B at the crimping point 40 between 11 and capstan 2
It is wrapped around 11.

Therefore, by rotating the capstan 2,
Reel A10 and reel B11 are simultaneously rotated by the frictional force at the crimping points 39 and 40, and the tape runs.

In such a single-starting system in which the tape is driven by a single capstan 2, the tape can be made to travel back and forth by changing the rotational direction of the capstan 2.
At this time, as described above, the crimping force of the reel on the take-up side must be made greater than the crimping force of the reel on the supply side.

Therefore, when traveling in the direction of arrow A in FIG. 3, the crimping force of reel B11 is made greater than that of reel AIO, and when traveling in the direction of arrow B, the crimping force of reel A is made greater than that of reel B. Therefore, it is necessary to change the pressing force of reel A10 and reel B11 depending on the running direction.

The mechanism for switching this pressure force is shown in Figures 4 and 5.
This will be explained in detail with reference to the drawings.

Figures 4 and 5 show the parts related to the variable pressure force mechanism provided on the back side of the chassis 1 in Figure 3, and Figure 4 shows when the vehicle is traveling in the direction of arrow A in Figure 3. , and FIG. 5 shows when the vehicle is traveling in the direction of arrow B.

Lever shaft 41. 42 is fixed to the chassis 1, and the switching levers 25 and 26 are rotatably supported by lever shafts 41 and 42.

These two switching levers 25 and 26 are connected to a connecting lever 29 by pins 43 and 44, so that they interlock with each other.

23 and 24 are reel arms, which are rotatable relative to the reel shirts 16 and 17, respectively, and have pins 47° set in the switching levers 25 and 26 in the arc-shaped elongated holes 45 and 46. 48 are fitted and can be slid along the elongated holes 45 and 46.

A spring 30 is bent between the reel arms 23 and 240, and presses the reel A10 and reel B11 to the capstan 2.

In addition, the solenoids 27 and 2B each have a rod 49.5.
0 to the switching lever 25.

Next, the operation of the variable pressure force mechanism configured as above will be explained.

When running the tape in the direction of arrow A in FIG. 3, the switching lever 25 is rotated clockwise by energizing the solenoid 27, and the switching lever 26 is also rotated in the same direction by the connection lever 29, as shown in FIG. becomes the state of

Considering the pressing force of reel A10 and reel B11 in this state, if the tensile force by the spring 30 is F, then the force PA applied to the reel A10 is The distance to the shadow position 51 is Ll, and the distance to the reel shaft 16 is L2.
Then, similarly, the force PB applied to the reel B11 is the reel arm 24
This is because the fulcrum of is the pin 48.

Comparing the magnitudes of PA and PB, it is clear that the following formula is obtained, and the pressing force PB of reel B11 is greater than the pressing force PA of reel A.

Conversely, when running the tape in the direction of arrow B in Figure 3,
By energizing the solenoid 28, the switching lever 25.
26 rotates counterclockwise to the state shown in FIG. 5, which is the opposite of that shown in FIG.

The pin 47 which is the fulcrum of the reel arms 23 and 24
．． By moving 48 using the switching levers 25 and 26, the pressing force can be switched between 4602 and 1052y.

According to the present invention, the pressing force can be switched reliably with a simple configuration.

That is, the crimp force can be switched by a single spring 30, and since frictional force is not used, it is stable against environmental changes.The force required to switch the crimp force can also be relatively small, so the solenoid 27, For 28, a small capacity one can be used.

Furthermore, the pressure difference can be varied over a fairly wide range by changing the spring deflection positions 51 and 52 of the spring 30.

Furthermore, as the tape is wound from reel A10 to reel B11 in the state shown in FIG.
O, both reels B11 move in parallel to the right, but Ll.

L2. L3. Since the size of L4 does not change, the crimp force ratio P
A/PB is constant.

(However, strictly speaking, Ll changes slightly due to the rotation of the reel arms 23 and 240, but since the rotation angle is small, it is considered to be constant in practice.

) Further, the magnitudes of PA and PB are determined by the tensile force F of the spring 30, but since the distance between the spring shadow positions 51 and 52 does not change much depending on the tape winding diameter, the variation in F is also slight.

Therefore, the magnitudes of PA and PB remain constant throughout.

[Brief explanation of the drawing]

1 and 2 are a schematic plan view and a side view showing a conventional tape drive device, FIG. 3 is a schematic plan view of a magnetic recording and reproducing device equipped with the tape drive device of the present invention, and FIGS. 4 and 5 Both figures show a schematic plan view of the main parts of the tape drive device of the present invention, FIG. 4 shows the state when the tape runs in the direction of arrow A in FIG. 3, and FIG. 5 shows the state when the tape runs in the direction of arrow B. Indicates the condition when driving. 2: Capstan, 10: Reel A, 11: Reel B,
23, 24: Reel arm, 25, 26: Switching lever, 27.28: Solenoid, 29 Two-connection lever, 3
0: Spring.

Claims (1)

[Claims] 1. A supply reel, a take-up reel, a capstan arranged to contact the supply reel and the take-up reel simultaneously on the circumferential surface, and one end of which is connected to each reel shaft of the supply reel and the take-up reel, respectively. A pair of reel arms that are rotatably provided and have an elongated end at the other end, and a pin that is rotatably supported by a lever shaft and erected at one end are respectively fitted into the elongated holes of the reel arms. a pair of switching levers that move the fulcrum positions of the reel arms together, a spring that applies a tensile force between the respective reel arms, and a spring that applies a tensile force between the respective reel arms; and a connecting lever that applies rotational force in the same direction, the tape drive device being characterized in that the pressure force of the supply reel and the take-up reel against the capstan can be changed depending on the rotational direction of the capstan.