JPH064427Y2 - Support structure for pinch roller for VTR - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a support structure for a pinch roller in a VTR.

[Prior Art] FIGS. 5 and 6 show an example of a tape running system in a VTR. In the figure, 11 is a feeding-side tape hub, 12
Is a video head drum, 13 is an audio head, 14
Is a capstan, 15 is a pinch roller, and 16 is a winding-side tape hub. By the way, in this type of capstan drive system, the roundness, runout, uneven rotation of the capstan shaft, the pressure contact condition of the capstan 14 with respect to the pinch roller 15, etc. directly affect the wah, flutter and jitter. The pinch roller 15 is required to have high accuracy. That is, as shown in FIG. 6, the capstan 14
Since the tape T sandwiched between the pinch roller 15 and the pinch roller 15 is fed by the capstan 14, the verticality of the capstan 14 and the pinch roller 15 is important for the feeding stability of the tape T. When the width of the tape T becomes about 1/2 inch, the capstan 14 is tilted with the pinch roller 15 tilted.
When the tape T is pressed against, the tape T is likely to move up and down, stretch to one side, or wrinkle. In order to solve this problem, the rubber roller 15 which constitutes the pinch roller 15 as shown in FIG.
a and a cylindrical body 15b are supported by a support shaft 17 via a single ball bearing 16, and an automatic centering mechanism is adopted in which the inclination of the pinch roller 15 can be absorbed by the gap between the ball 16a and the retainer 16b. ing.

[Problems to be solved by the invention]

However, in the pinch roller 15 described above, the holding screw 18 and the collar 19 for fixing the inner ring or the outer ring of the ball bearing 16 are required, which increases the number of parts and complicates the structure and complicates the assembling work. It was a problem because it does. Furthermore, in order for the pinch roller 15 to perform smoothly, high dimensional accuracy is required for each component,
There was no choice but to increase the number of manufacturing or assembly processes.

In view of such circumstances, it is an object of the present invention to provide a pinch roller support structure that can be easily assembled with a reduced number of parts and that can ensure smooth rotation as this type of pinch roller.

[Means and Actions for Solving Problems]

In the pinch roller support structure according to the present invention, a spherical head is formed at the tip of the support shaft, and a cylindrical inner peripheral surface into which the head is fitted and a frusto-conical inner circumference connected to the cylindrical inner peripheral surface via a grip. A bush made of synthetic resin having a press-fitting portion defining a recess having a surface and a slit formed in an upper portion of the frusto-conical portion of the press-fitting portion, and a bush of the pinch roller via the press-fitting portion. It is pressed into the inner hole. The pinch roller is supported by the support shaft via a bush, and the bush and the spherical head of the support shaft perform a self-aligning action to allow smooth operation of the pinch roller.

〔Example〕

An embodiment of a pinch roller support structure according to the present invention will be described below with reference to FIGS. 1 to 4. In the figure, 1 is a roller for sandwiching a tape T between it and a capstan so that it can run in a predetermined direction. 2 is a rubber having an inner hole 2a and an intermediate wall 2b into which a bush described later is press-fitted. And the like, which is made of a metal, to which the elastic roller 1 is attached, 3 is the inner hole 2
A bush made of synthetic resin, which is composed of a slightly tapered cylindrical outer peripheral surface defining a press-fitted portion 3a into a, and a frusto-conical surface continuous with the cylindrical outer peripheral surface. A head portion 3b into which 4a is inserted is formed, and a tip surface 3 of a part of the concave portion 3b, that is, the truncated conical surface portion is formed.
A plurality of slits 3d (see FIG. 3) that meet at the center of c are formed. Further, as shown in the bush 3 Figure 4, the recess 3b is, the inner surface of the press-fit portion 3a is in contact with the side region of the support shaft of the head 4a to be described later circumferential surface 3b ₁ formed by being molded into a cylindrical shape The grip portion 3b ₂ and a corner portion 3b ₃ (see FIG. 2) that cannot come into contact with the head portion are defined, and a cutout hole 3e to which the slit 3d should join is formed in the tip surface 3c. There is. 4 is a concave portion 3b of the bush 3 at its tip
The support shafts 5 for supporting the pinch rollers having the spherical heads 4a to be fitted thereinto are bases on which the support shafts 4 are implanted. In the above case, the bushing 3 is injection molded using a synthetic resin, press-fitting allowance fitting margin with respect to the bore 2a of the cylindrical body 2 of the press-fit portion 3a with respect to the head 4a of the circumferential surface 3b ₁ of the support shaft 4 Is also set to be large.

Since the support device for the pinch roller according to the present invention is configured as described above, the pinch roller can be supported by the support shaft 4 only via the bush 3, and the number of parts is reduced as a support device of this type, and the pinch roller is used. The roller can be easily assembled and the number of assembling steps can be reduced. That is, when the assembly is first, but fitting the head 4a of the support shaft 4 to the recess 3b of the bush 3, is disconnected by the slit 3d together with the inner circumferential surface 3b ₁ can be easily fitted because they are formed into a straight Since the frusto-conical surface portion of the bush 3 can be appropriately bent outward, the head 4a is completely fitted.
Further, the cylindrical body 2 of the bush 3 fitted to the head 4a of the support shaft 4
When press-fitting into the inner hole 2a of the bush 3, the bush 3 can be easily inserted from the frusto-conical surface portion, and the tip surface 3c abuts the intermediate wall 2b of the cylindrical body 2 so that the height of the pinch roller relative to the support shaft 4 or the base 5 is increased. The position can be accurately determined. The press-fitting portion 3a is deformed so that the diameter of the lower end portion of the inner peripheral surface 3b ₁ becomes smaller by being press-fitted into the inner hole 2a (arrow A in FIG. 2), whereby the head 4a is fitted into the recess 3b. Becomes reliable, and the removal of the head portion 4a after the insertion is completely prevented. At this time, the head 4a is moderate contact pressure between the gripping portion 3b ₂ are resiliently embraced by the grip portion 3b ₂ by the elastic deformation of the frustoconical surface of the bushing 3 occurs, the bush 3 is synthesized Since it is made of resin, an appropriate rotational movement between them can be performed, and the press-fitting pressure of the press-fitting portion 3a generated in the inward direction 2a of the tubular body 2 is larger than the contact pressure, so that the bushing is formed. 3 is prevented from idling with respect to the cylindrical body 2, and thus a smooth rotation of the pinch roller supported by the support shaft 4 is guaranteed. In this case, the rotation of the pinch roller is not only performed in the direction orthogonal to the support shaft 4, but also the angle at which the pinch roller can be tilted with respect to the support shaft 4 depending on the size of the gap between the inner hole 2a of the cylindrical body 2 and the support shaft 4. Since the tilting rotation is allowed in (1), the self-centering action of the pinch roller is ensured and the proper running of the tape T is guaranteed.

The bush 3 can be prevented from idling with respect to the tubular body 2 by forming the press-fitting portion 3a in the above embodiment into a square cross-section and molding the cross-section of the inner hole 2a in accordance therewith.
The support shaft from the recess 3b such as by forming an appropriate projection of the outer peripheral surface of the press-fit portion 3a even when a complete cylindrical, considering the press-fit interference for the inner hole 2a, or on the inner peripheral surface 3b ₁ It is possible to prevent the head portion 4a of 4 from coming off. Further, the number of slits 3d and the like are not limited to those in the above embodiment, and can be increased or decreased.

[Effect of device]

As described above, according to the present invention, the number of parts of the pinch roller supporting device is reduced, and thus the pinch roller mounting work can be performed quickly. Further, since the head of the support shaft is spherical and the pinch roller is supported through the bush, the pinch roller can be tilted according to the state of the tape and smoothly rotate. In addition, the bush is made of synthetic resin. As a result, the frictional force is reduced, resulting in good rotation of the pinch roller. Further, the bush has an advantage that it acts as a retainer and can relax its dimensional accuracy.

[Brief description of drawings]

1 to 4 relate to an embodiment of a support structure for a pinch roller according to the present invention. FIG. 1 is a vertical sectional view showing the entire structure, and FIG. 2 is an enlarged sectional view of an essential part of FIG. FIG. 3 is a perspective view of the bush, FIG. 4 is a vertical sectional view of the bush, FIGS. 5 and 6 are plan views and perspective views of a main portion illustrating a tape running system, and FIG. 7 is a conventional pinch roller. FIG. 3 is a vertical sectional view showing the supporting structure of FIG. 1 ... rubber roller, 2 ... cylindrical body, 2a ... inner hole, 3 ...
Bush, 3a ... Press-fitting portion, 3b ... Recessed portion, 3d ... Slit, 3e ... Notched hole, 4 ... Spindle, 4a ... Head,
5: Base, T: Tape.

Claims (1)

[Scope of utility model registration request] 1. A VTR in which a cylindrical body to which an elastic roller is attached is rotatably supported by a support shaft fixed to a base.
In the pinch roller for use, a spherical head portion is formed at the tip of the support shaft, and a cylindrical inner peripheral surface into which the head portion is fitted and a truncated conical inner peripheral surface connected to the cylindrical inner peripheral surface via a grip portion. A VTR pinch roller in which a synthetic resin bush having a press-fitting portion that defines a recess and a slit formed on the top of the press-fitting portion is press-fitted into the inner hole of the cylindrical body through the press-fitting portion. Support structure.