JPH0313662B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape drawer positioning device for a cassette type VTR.

An example of a conventional device of this type will be explained with reference to FIGS. 1 and 2. These figures show a state in which the tape drawer block is accommodated in a holder for holding and positioning the block, and FIG. 1 shows a plan view thereof, and FIG. 2 shows a partially sectional side view thereof.

The guide roller block consists of a guide roller 3 screwed into a holder shaft 2 installed on the guide roller base 1, an inclined guide block 4 attached to the guide roller base 1 with screws, etc.
Projection 1 provided below the guide roller base 1
c is placed so that it can slide in a guide groove 6a provided in the chassis 6. A pin 5a of the drive link 5 is attached to this protrusion 1c. Therefore, the guide roller block receives a force from the pin 5a of the drive link 5 through the protrusion 1c, and is guided by the guide groove 6a provided in the chassis 6 and moves in the direction of arrow A. At this time, the tape is pulled out from the cassette.

On the other hand, a base 7 holding a rotating head cylinder (not shown) is placed on the chassis 6. Further, a catcher 8 is placed on the base 7 to engage and hold the moved guide roller block in a desired position.

Here, the positioning of the guide roller block on the XZ plane is performed using a V
The groove 8a fits into the V-shaped protrusion 1a provided at the tip of the guide roller base 1, and the protrusion 7b protrudes above the base 7 and the protrusion 7b below the inclined guide block 4. This is determined by the engagement of the protrusion 4a provided so as to come into contact with. Alternatively, it is determined by the above-mentioned former and the contact between the upper surface of the chassis 6 and the sliding portion 1b provided below the guide roller base 1.

In addition, positioning on the YZ plane is achieved by using the U-shaped groove 8b provided on the catcher 8 and the guide roller shaft 3.
a, and the engagement of the holder shaft 2 with the U-shaped groove 8c provided below.

Further, positioning in the XY plane is determined by the fitting between the U-shaped groove 8c and the holder shaft 2, and the projection 1c provided below the guide roller base 1 and the guide groove 6a.

However, the conventional positioning method as described above has the drawback that positioning in the XY plane and the XZ plane tends to vary widely. because,
The positioning of the XZ plane is the top surface of the chassis 6 and the sliding part 1.
In the case determined by the abutment of b, the chassis 6 is a fairly large plate-shaped body, and is generally made by press working to reduce cost. When the chassis 6 is made by press working, the dimensions in the thickness direction are generally as follows due to its bending.
It is not always constant. Furthermore, materials with high rigidity cannot be used for the chassis 6. Therefore, the surface of the chassis 6 at the contact portion with the sliding portion 1b varies, and the position of the sliding portion 1b varies. Further, even when the position on the XZ plane is determined by the protrusion 4a and the protrusion 7b, the position is determined via the protrusion 4a. In this case, since the position of the protrusion 4a is determined via the guide roller base 1 and the inclined guide block 4, the accumulation of dimensional tolerances of each of these parts increases.
In addition to variations in the surface of the chassis 6, variations in rotation in the vertical direction in the XZ plane occur.

When variations occur in the XY and XZ planes due to the reasons described above, these variations ultimately result in positional variations of the guide roller 3. For this reason, there is a drawback that the precision of the tape guide deteriorates, making it difficult to obtain good tape running.

Furthermore, in the case where the positioning of the tape drawer block is made up of multiple parts as described above, in order to suppress the positional variation of the guide roller 3, it is necessary to improve the dimensional accuracy and assembly accuracy of each single part. This has the disadvantage that it also leads to increased costs due to secondary processing, etc.

The purpose of the present invention is to eliminate the above-mentioned drawbacks,
To provide a tape drawer positioning device with improved positioning accuracy.

A feature of the present invention is that first and second catchers are disposed on both sides of a rotary cylinder containing a rotary head mounted on a substrate, and that the first and second catchers In a tape drawer positioning device comprising first and second guide roller blocks that are engaged and held, respectively, the guide roller block has a V protrusion facing the catcher and a protrusion provided below. a holder shaft installed substantially perpendicularly to the guide roller base; and means for applying a force to press the protrusion 17 to one side in a plane parallel to the substrate. , the catcher abuts and engages with the upper part of the holder shaft and restricts the movement position at the abutment point; a V-shaped support part abuts and engages with the upper surface of the V-shaped protrusion; a V-groove upper surface for regulating vertical movement; a protrusion formed on the arm that abuts and engages with the protrusion and regulates rotation in the vertical direction; U-shaped groove that restricts rotation in a plane perpendicular to the direction of movement of the roller block;
and the protrusion includes an inner surface abutted and engaged by the pressing force of the means, and includes an arm that cooperates with the U-shaped groove to restrict rotation in a plane parallel to the substrate. It is in.

The present invention will be explained below using examples. FIG. 3 is a plan view schematically showing a VTR mechanism using the present invention, showing a stopped state with a tape stored in a cassette. FIG. 4 is a plan view of a normal playback state in which the tape drawer pulls out the tape from the inside of the cassette to a required running path and causes the tape to run.

Tape 12 stored in cassette 11
is pulled out by first and second guide roller blocks 17 and 18 that move while being guided by the first guide groove 14, second guide groove 15 and sub-plate 16 of the main chassis 13. First and second guide roller blocks 17 and 1 are attached to first and second catchers 21 and 22 that are fixed on a base 20 that holds a rotating head cylinder 19 that is fixed to the main chassis 13.
8 is engaged and held, so that the tape 12 is mounted on a predetermined running path.

Here, the first catcher 21 and the second guide roller block 18 according to an embodiment of the present invention
The structures of will be explained with reference to FIGS. 5 and 6, respectively. Figures 5 and 6 show the first catcher 21, respectively.
and a perspective view of the second guide roller block 18.

As shown in FIG. 5, the first catcher 21 includes a V-shaped support portion 21a that engages with the holder shaft of the guide roller block, and a protrusion portion provided below the guide roller base of the guide roller block. 18e and an arm 21b with which the inner surface 21d engages. A protrusion 21c is formed on the upper surface of the arm 21b.
A U-shaped groove 21e is formed on the side surface of the base.

On the other hand, the second guide roller block 18
As is clear from the figure, it has a guide roller 18a, a holder shaft 18b, a V protrusion 18c, a guide roller base 18d, a protrusion 18e, and an inclined guide block 18f screwed to the guide roller base 18d.

first and second guide roller blocks 17,
18 are the first and second catchers 21,
The first guide roller block 17 located on the left side of the rotary head cylinder 19 will be described below to make the explanation easier to understand, since it is functionally substantially symmetrical.

7 and 8 respectively show a plan view and a partially sectional side view of the first guide roller block 17 engaged with the first catcher 21 on the left side of the rotary head cylinder 19. Also,
FIG. 9 shows a bottom view in the same state as Nos. 7 and 8.

The positioning of the first guide roller block 17 is the same as in the conventional example in the YZ plane, so a description thereof will be omitted. What is different from the conventional example is the XY and
This is a positioning point within the XZ plane.

The positioning of the first guide roller block 17 in the XZ plane is determined by the fact that the V-shaped support portion 21a of the first catcher 21 and the holder shaft 17b of the first guide block 17 are pressed together. This pressing force is constantly applied to the first guide block 17 by the drive link 23. On the other hand, the vertical movement of the guide roller base 17d is caused by the first
The upper surface 21f of the V groove portion of the catcher 21 and the upper surface 17 of the V protrusion 17h at the tip of the guide roller base 17d.
Determined by c. Further, the vertical rotation in the XZ plane is caused by the protrusion 17g provided below the guide roller base 17d and the first catcher 2.
An arm 21 is provided to protrude from the lower part of the first guide roller block 17 in the moving direction of the first guide roller block 17.
It is determined by the engagement of b with the protrusion 21c.

Further, the positioning of the first guide roller block 17 in the XY plane is performed by the first catcher 21.
Contact between the U-shaped groove 21e provided below and the holder shaft 17b, and the guide roller base 17d
The protrusion 17e and arm 21b provided below the
It is determined by the abutment of the inner surface 21d of. In addition, the first
Similarly to the above, a biasing force is applied to the protrusion 17e of the guide roller block 17 by the drive link 23 so that the protrusion 17e always comes into contact with the inner surface 21d. Furthermore, the first catcher 21 is configured such that the first guide roller block 17
It is mounted so that when it is engaged and held upward, it rises above the upper surface of the main chassis 13, leaving a gap.

As is clear from the above description, the positioning of the first guide roller block 17 according to this embodiment is mainly determined by the dimensions of the upper surface 17c of the V protrusion 17h and the protrusion 17g of the guide roller block 17. However, this V protrusion upper surface 17c and the protrusion 17g
Both of these surfaces are conventionally machined for accuracy reasons. Therefore, even if the dimensional accuracy of these parts is improved, the cost will hardly increase compared to the conventional method. Further, in this embodiment, unlike the conventional device, the main chassis 13 and the inclined guide block 17f are not used for positioning, so the main chassis 13, which is a pressed product, is not used for positioning.
It is not affected by the flatness of the block or the accumulation of dimensional tolerances due to the use of the inclined guide block 17f. Therefore, the accuracy is better than that of the conventional example.

As explained above, according to the present invention, it is possible to obtain a tape drawer positioning device that is more accurate than the conventional one without increasing costs, and it is possible to improve tape running accuracy. Furthermore, even in automatic assembly, etc., the elements of the tape drawer positioning section are configured as one part, which has the effect of preventing positioning variations during assembly.

Furthermore, according to the present invention, when the lower part of the holder shaft abuts and engages with the U-shaped groove, the protrusion 17e abuts and engages the inner surface 21d of the arm, so that the projecting portion 17e abuts and engages with the inner surface 21d of the arm. It can be expected that the rotation of the guide body can be restricted, and the positioning accuracy of the entire tape guide body can be greatly improved.

[Brief explanation of drawings]

Figure 1 is a plan view of the conventional example, Figure 2 is a side view of the conventional example, and Figures 3 and 4 are of an embodiment of the present invention.
FIG. 5 is a schematic diagram of the VTR mechanism, and FIG. 5 is a side view of a catcher, which is a component of an embodiment of the present invention.
The figure is a side view of a guide roller block which is another component of an embodiment of the present invention, FIG. 7 is a plan view of an embodiment of the present invention, FIG. 8 is a side view thereof, and FIG. 9 is a bottom view thereof. Show the diagram. 11...cassette, 12...tape, 13...
Main chassis, 14, 15... Guide groove, 16...
...Subplate, 17, 18...First and second guide roller blocks, 19...Rotating head cylinder, 21, 22...First and second catcher, 1
7a... Guide roller, 17b... Holder shaft, 17c... V protrusion, 17d... Guide roller base, 17e... Protrusion, 17f... Inclined guide block, 17g... Protrusion, 21a... V-shape shaped support part, 21b... arm, 21c... protrusion, 2
1d...inner surface, 21e...U-shaped groove, 21f...
Top surface of V groove.

Claims (1)

[Scope of Claims] 1. First and second catchers 21 and 22 arranged on both sides of a rotary cylinder containing a rotary head mounted on a substrate, and the first and second catchers 21 and 22 disposed on both sides of a rotary cylinder containing a rotary head mounted on a substrate, and the In a tape drawer positioning device comprising first and second guide roller blocks 17 and 18 that are engaged and held by two catchers, respectively, the first and second guide roller blocks 1
7 and 18 are substantially symmetrical, and the first guide roller block 17 has a V protrusion 17h facing the catcher and a protrusion 1 provided below.
7g and a protrusion 17e, a holder shaft 17b that is installed approximately perpendicularly to the guide roller base, and the protrusion 17.
e to one side in a plane parallel to the substrate, and the first catcher 21 abuts and engages with the upper part of the holder shaft 17b. , a V-shaped support portion 21a that restricts the movement position at the contact point, a V-shaped groove upper surface 21f that abuts and engages with the upper surface 17c of the V protrusion 17h and restricts the vertical movement of the guide roller block, and the protrusion. a protrusion 21c formed on the arm that abuts and engages with the holder shaft 17g to restrict rotation in the vertical direction; U-shaped groove 2 that restricts rotation within the plane
1e, and the protrusion 17e is connected to the means (2).
The inner surface 21d is abutted and engaged by the pressing force of 3).
and an arm 21b that cooperates with the U-shaped groove to restrict rotation in a plane parallel to the substrate.