JPH0412553B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a helical scan type VTR for supporting a cylinder etc. equipped with a rotating magnetic head.
The present invention relates to a chassis structure suitable for a portable VTR, which particularly requires light weight.

[Background of the invention]

In general, a helical scan VTR that uses a tape cassette to record and play back signals has a tape running mechanism that rotates a reel to run the magnetic tape wound on the reel in a predetermined direction, and a tape running mechanism that rotates the reel to run the magnetic tape wound on the reel in a predetermined direction. A tape loading mechanism is used in which the tape is pulled out and loaded onto the tape traveling path around the rotating magnetic head.The main components of the tape traveling mechanism and the tape loading mechanism are attached to the horizontal surface of the chassis, and the tape loading mechanism is attached to the horizontal surface of the chassis. A cylinder with a cylinder is attached to the inclined surface of the chassis.

Conventionally, such chassis can be roughly divided into two types: one is integrally formed by die-casting, and the other is one in which the horizontal part is formed by pressing a flat plate, the inclined part to which the cylinder is attached is formed by die-casting, etc., and then both are fixed with screws etc. There are two known types: one that is integrated with steel, and one that is formed integrally with reinforced plastic. Among these, when the chassis is manufactured by die casting, it has the advantage that the horizontal surface and the inclined surface can be integrally formed, but if the wall thickness is made thin, the flow of the metal becomes poor, and therefore a thin and lightweight chassis is provided. The disadvantage is that it is difficult to do. In addition, when manufacturing a chassis as a combination of a pressed part and a die-cast part, the wall thickness of the horizontal part can be set relatively freely, but in order to ensure the rigidity of the pressed part, the wall thickness cannot be made too thin. Moreover, since the chassis consists of two members, the assembly work is complicated. Furthermore, when the chassis is made of reinforced plastic, there is a limit in rigidity and strength due to the nature of the material, which also has the disadvantage that the wall thickness cannot be made very thin. Each of the drawbacks of the conventional technologies explained above is an impediment to reducing the weight of the chassis, especially for portable chassis that require weight reduction.
This was a big problem when applying chassis to VCRs.

[Purpose of the invention]

The purpose of the present invention is to eliminate the drawbacks of the prior art described above, and to achieve weight reduction while ensuring overall rigidity.
Our goal is to provide chassis structures for VTRs.

[Summary of the invention]

In order to achieve this object, the present invention applies a drawing process to the sloped surface that supports the cylinder to increase the rigidity of the sloped surface compared to other parts when the chassis is integrally formed by press working. Moreover, a feature is that guide holes for tape loading are punched around the sloping surface to prevent deformation of the entire chassis from reaching the sloping surface.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are plan views showing an example of a VTR equipped with a chassis according to the present invention, with FIG. 1 showing an unloading state and FIG. 2 showing a loading state. In these figures, 1 is a chassis, 2 is a capstan motor that rotationally drives a capstan 3, 4 is a pinch roller, 5 is a supply reel stand, 6 is a take-up reel stand, 7, 8, 9, 10 are gears, 11 is a belt wound around the pulley part (not shown) of the capstan motor 2 and the gear 7, and the rotation of the capstan motor 2 is caused by the belt 11,
It is transmitted to the take-up reel stand 6 via gears 7, 8, 9, and 10. 12 is a loading motor fixed to chassis 1, 13 is a pulley, and 14 is pulley 1.
3 and a belt wound around the pulley 12a of the loading motor 12, 15 a worm fixed to the rotating shaft of the pulley 13, 16 a worm gear that meshes with the worm 15, and 17 a worm wheel that meshes with the worm gear 16. , 18 is an arm supported on a support shaft 19;
A pin (not shown) engages with a cam groove (not shown) on the worm wheel 17, so that the worm wheel 17 is rotated clockwise and counterclockwise about the support shaft 19 in conjunction with the rotation of the worm wheel 17. Ru. 20 is a gear that meshes with a gear portion carved on the tip of the arm 18; 21 is a gear that meshes with the gear 20; 22;
23 is an arm fixed to gears 20 and 21;
4 and 25 are connected to the arm 2 via links 26 and 27.
2 and 23, and these guide blocks 24 and 25 are arranged along a pair of guide holes 28 and 29 formed in the chassis 1 to the tape storage position shown in FIG. 1 and the tape storage position shown in FIG. It is moved back and forth between the tape running position shown.

Reference numeral 30 denotes a tape cassette, and within the tape cassette 30, a supply reel 32 and a take-up reel 33 on which a magnetic tape 31 is wound are arranged in parallel. 34 is a cylinder attached to the chassis 1 in an inclined state with respect to the horizontal plane, and includes inclined pins 35 and 36 for correctly winding the magnetic tape 31 around the cylinder 34, and for regulating the vertical position of the magnetic tape 31 during running. Guide roller 3 for
7 and 38 are provided on the guide blocks 24 and 25.

In the VTR described above, when the loading motor 12 rotates in the unloading state shown in FIG.
It is transmitted to the worm wheel 17 via the worm 15 and the worm gear 16, and the engagement of the cam groove on the worm wheel 17 with the pin of the arm 18 causes the arm 18 to rotate counterclockwise around the support shaft 19. This causes gear 20 to rotate clockwise and gear 21 to rotate counterclockwise. Then, both the guide blocks 24 and 25 are moved into the guide holes 28 and 29 by the arms 22 and 23 that rotate in conjunction with the gears 20 and 21 and the links 26 and 27 that are pivotally connected to the arms 22 and 23. A well-known tape loading mechanism is constructed in which the magnetic tape 31 is pulled out from the tape cassette 30 by the guide blocks 24 and 25 and wound around the cylinder 34. There is. In addition, the magnetic tape 31
is the driving force of the take-up reel stand 6 which rotates from the capstan motor 2 via the belt 11 and gears 7, 8, 9, 10, the capstan 3 which is rotated by the capstan motor 2, and the capstan 3 which is pressed against the capstan 3. By constant flux driving with the pinch roller 4,
It constitutes a well-known tape running mechanism that winds the tape from the supply reel 32 of the tape cassette 30 to the take-up reel 33. The main components of the tape loading mechanism and the tape running mechanism are attached to predetermined positions on the horizontal surface of the chassis 1, and the cylinder 34 is attached to the inclined surface of the chassis 1.

3 to 5 are explanatory diagrams showing details of the chassis 1, and FIG. 3 is a plan view of the chassis,
FIG. 4 is a sectional view taken along the line -- in FIG. 3, and FIG. 5 is an enlarged sectional view of a convex portion provided on the inclined surface of the chassis.

The chassis 1 is made of a thin metal plate made of an aluminum alloy, and is integrally formed by bending, punching, drawing, or other press processing. That is, the four sides of the chassis 1 are bent in order to increase the overall rigidity, and a plurality of holes including the guide holes 28 and 29 are formed in the horizontal plane by punching.
An inclined surface 39 for attaching the cylinder 34 is formed between the holes 9 by drawing. As shown in FIG. 4, this inclined surface 39 has its left side in the drawing located below the horizontal plane, and its right side in the drawing located above the horizontal plane, and is narrowed in both the front and back directions of the chassis 1 so as to cross the horizontal plane. Compared to the case where the inclined surface 39 is formed on either the front or back surface of the chassis 1, the amount of drawing can be reduced.
Processing can be simplified. Further, at three locations on the inclined surface 39, protrusions 41 having mounting holes 40 are formed in a half-punch shape by punching, and the cylinder 34 is placed in an inclined state using the surface of the protrusions 41 as a reference plane.
Point supported.

In the chassis 1 configured in this way,
By drawing the sloped surface 39, the rigidity of the part where the cylinder 34 is attached can be made higher than other parts, and each convex part 41 formed on the sloped surface 39 can be used as a reference surface for mounting the cylinder 34. This makes it possible to improve the mounting accuracy, and furthermore, by punching the guide holes 28 and 29 so as to surround the inclined surface 39, deformation of the entire chassis 1 can be prevented from affecting the inclined surface 39.

FIG. 6 is a front view showing details of the cylinder 34. As shown in FIG. 6, the cylinder 34
consists of a rotatable upper cylinder 34a and a fixed lower cylinder 34b, a magnetic head 42 is attached to the upper cylinder 34a, and a motor 43 is attached to the lower cylinder 34b. The cylinder 34 has a mounting surface 34c on the lower surface of the lower cylinder 34 that is attached to the inclined surface 39 of the chassis 1.
A lead 34d is cut on the circumferential surface of 4 with reference to the mounting surface 34c. This lead 34d
is for creating a running path for the magnetic tape 31 by coming into contact with the lower edge of the magnetic tape 31 during running, therefore, when attaching the mounting surface 34c of the cylinder 34 to the inclined surface 39 of the chassis 1. The lead 3
If the linearity of 4d is not maintained, there is a drawback that complete compatibility of the magnetic tapes will not be achieved in VTRs in which the video track width recorded on the magnetic tape 31 is extremely narrow, such as several tens of microns. However, in this embodiment, as described above, the chassis 1
The rigidity and surface precision of the sloped surface 39 can be increased, and the influence of deformation of the entire chassis 1 on the sloped surface 39 can be reduced, so that when the cylinder 34 is attached to the sloped surface 39, the linearity of the lead 34d can be improved by several microns. It is possible to keep the error within the range.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a chassis that is lightweight and inexpensive while ensuring the required rigidity, and is therefore highly effective in portable VTRs where weight reduction is desired.

[Brief explanation of drawings]

The figures are all for explaining the embodiments of the present invention, and FIG. 1 is a plan view showing the unloading state of the VTR, FIG. 2 is a plan view showing the loading state of the VTR, and FIG. 3 is a plan view of the chassis. Figure 4 is the third
FIG. 5 is an enlarged sectional view showing a convex portion formed on the inclined surface of the chassis, and FIG. 6 is a front view of the cylinder. 1... Chassis, 28, 29... Guide hole, 34
... Cylinder, 34a ... Upper cylinder, 34b
...Lower cylinder, 34c...Mounting surface, 34d...
...Lead, 39...Slope, 40...Mounting hole, 4
1...Protrusion, 42...Magnetic head.

Claims (1)

[Claims] 1. A cylinder equipped with a rotating magnetic head, a tape loading mechanism that moves a magnetic tape wound between two reels from a tape storage position to a tape running position along a guide hole, and a tape that rotationally drives the reel. In a VTR in which the cylinder, tape loading mechanism, and tape traveling mechanism are attached to a chassis, an inclined surface of a portion that supports the cylinder in an inclined state is formed by drawing, and the inclined surface is A chassis structure for a VTR, characterized in that the guide hole is formed around the guide hole by punching, and the chassis is integrally formed by pressing.