JPH0428046A - Noise preventing device for tape guide roller device - Google Patents

Abstract

PURPOSE:To prevent a harsh noise occurring with simple constitution by abutting a vibration absorbing material on the upper flange of a tape guide roller device. CONSTITUTION:The vibration absorbing material 20 is comprised of rubber with high flexibility and elasticity, and the vibration absorbing material 20 is abutted on the upper flange 18 by adhering on the upper terminal plane of the upper flange and that of a shaft bar 18. In such a way, vibration generated in the upper flange 18 can be absorbed by abutting the upper flange 18 on the vibration absorbing material 20, and resonance generated in the shaft bar 17, a lower flange 19, and a supporting board 16 due to the vibration can be blocked. Thereby, it is possible to prevent the harsh noise occurring with the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a noise prevention device for a tape guide roller device in a VTR or the like.

[Prior Art] Generally, a VTR having a tape running system as shown in FIG. 2 is known. In FIG. 2, 1 is a cassette, and the cassette has a magnetic chip 12 wound thereon.
is stored. Reference numeral 3 denotes a head drum equipped with a rotating head', and the magnetic tape 2 wrapped around the circumferential surface of the head drum in a substantially omega shape is rotated in the running direction of the magnetic tape 20 by the aforementioned rotating head (not shown). is scanned in an inclined direction to record or reproduce a video signal. 4.5
is a tape guide roller rotatably supported on a movable support base (not shown in FIG. 2), which is located at the position indicated by the dashed line when the cassette 1 is loaded, and at the position indicated by the dashed line after the cassette is loaded. It moves like an arrow. Due to this movement, the tape 2 is pulled out from the cassette 1,
The spatula F') is wrapped around the circumferential surface of the ram 3 in a substantially Ω shape.

The magnetic tape 2 pulled out from the cassette 1 in this way has a guide pin 6 disposed along its running path, a full-width erasing head 7, an audio/CTL head 8, and a guide pin 9.
In addition to being in contact with the tape guide roller 4.5, it is also in contact with the inclined guide ball 10.11 that moves together with the tape guide roller 4.5, and is pressed against the capstan 12 by the pinch roller 13 to run at a constant speed. A tension pin 14 keeps the tension of the running magnetic tape 2 substantially constant.

The tape running system described above is for the case where the magnetic tape 12 is run at a constant speed, but when the tape 2 is run at high speed such as fast forwarding or rewinding, the magnetic tape 2 is moved from the cassette 1 to the tape guide roller 4.5. is pulled out and wrapped around the circumferential surface of the head drum 3 in a substantially Ω shape. However, in the case of this high-speed running, the pinch roller 13 is separated from the capstan 12.

The tape guide roller 4.5 described above is incorporated into a tape guide roller device 15 as shown in FIG. That is, in Figure 2,
Reference numeral 16 denotes the above-mentioned movable support stand, on which the shaft rod 1 is attached.
7 is implanted, and the above-mentioned tape guide roller 4 is installed on the shaft rod.
is rotatably mounted. In addition, the shaft rod 17
The upper flange 18 regulates the upper and lower edges of the magnetic tape 2 guided by the tape guide roller 4.
and the lower flange 19 are fixed by press fitting.

When the magnetic tape 2 runs, only the upper edge of the magnetic tape 2 is regulated by the upper flange 18 so that the lower edge of the magnetic tape comes into contact with the lead portion (not shown) of the head drum 30 described above. It looks like this. For this reason,
The magnetic tape 2 is subjected to a force that moves it upward along the axial direction of the shaft rod 17.

[Problems to be Solved by the Invention] By the way, when the magnetic tape 2 is run at high speed as described above, the tape guide roller 4 rotates at high speed, and
As the magnetic tape 2 rises, its upper end surface comes into contact with the upper flange 18. When this contact force increases, stick-slip occurs due to minute fluctuations in the friction between the tape guide roller 4 and the upper flange 18, and the resulting vibrations are transmitted to the shaft rod 17, lower flange 19, and support base 16. This resonance, which causes resonance, is a high-pitched sound (noise) that is harsh on the ears.

The present invention provides a noise prevention device for a tape guide roller device, which can remove the above-mentioned harsh noise by a simple means.

[Means for Solving the Problems] In order to solve the above problems, the present invention brings a vibration absorbing material into contact with the upper flange of the tape guide roller device.

[Operation] By bringing the vibration absorbing material into contact with the upper flange of the tape guide roller device, the vibration generated at the upper flange is absorbed,
Since the vibration is not transmitted to the shaft rod, lower flange, and support base, the above-mentioned resonance does not occur.

It is not clear why the vibration of the upper flange is absorbed by attaching a vibration absorbing material to the upper flange, but a vibration absorbing material made of highly flexible rubber (product name: Sorbothane) is attached to the upper flange by adhesive. In the inventor's experiments, the above-mentioned harsh noise could be removed. The reason why noise is removed in this way is considered to be that vibrations transmitted through soft elasticity are absorbed by the mass of the vibration absorbing material.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 is a sectional view showing the tape guide roller device.
Components equivalent to those in FIG. 3 described above are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In FIG. 1, reference numeral 20 denotes a vibration absorbing material, which is made of highly flexible and highly elastic rubber (trade name: Sorbo). The vibrations that occur in the shaft are absorbed, and the resonance that occurs in the shaft rod 17, lower flange 19, and support base 16 due to the vibrations is suppressed, thereby preventing noise.

Note that the means for bringing the vibration absorbing material 20 into contact with the upper flange 18 is not limited to adhesion; for example, the vibration absorbing material 20 may be configured to be pressed against the upper flange by an elastic member.

[Effects of the Invention] As described above, in this invention, since the vibration absorbing material is brought into contact with the upper flange of the tape guide roller device, it is possible to absorb the vibration generated in the upper flange, and thus the tape guide roller device This makes it possible to prevent such noise with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the present invention, FIG. 2 is a schematic plan view showing a tape running system of a generally known VTR, and FIG. 3 is a longitudinal sectional front view showing a conventional tape guide roller device. It is a diagram. 2: Magnetic tape, 4: Tape guide roller, 15: Tape guide roller device, 16: Support stand, 17: Axis rod, 18
: Upper flange, 20: Vibration absorbing material.

Claims (1)

[Claims] A tape guide roller that is rotatably provided on the shaft, and an upper flange that is fixed to the shaft so that the upper edge of the tape comes into contact with the shaft. 1. A noise prevention device for a tape guide roller device, characterized in that the noise prevention device includes a vibration absorbing material abutted on the upper flange.