JPH04175538A - Reel driving belt - Google Patents

Abstract

PURPOSE:To provide a reel driving belt which is less vibrative and less risk of being out of the track by introducing the belt core arrangement having such an uneven pitch as dense at the parts near the side faces and coarse in the central part, and thereby eliminating deformation of the belt. CONSTITUTION:A transmission belt 1 consists of twisted cores 2 of thin fibers at a pitch P1 finer near the side faces of the belt and a coarse pitch P2 in the central part. The constitution in other respects is the same as conventional. Even though the drive force transmission path is the same as conventional, the parts at the belt side faces 11 where the tension enlarges have greater core 2 distribution density than the belt center to provide well balancing of the tension per unit number of cores, and the cores are free from generation of excessive tension and perform rotating a reel disc for taking-up of a reel driving tape. This reduces easily deformation and/or vibration which might be generated on the reel driving belt, to enable accurate feeding of a magnetic tape, and a video tape recorder with high picture and sound qualities is accomplished at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reel driving belt for tape winding, which is mainly used in magnetic recording and reproducing devices such as video tape recorders.

[Conventional technology]

FIG. 2 is a sectional view of a conventional reel driving belt, and FIG. 3 is a view of the belt being hung on a bobbin.

In the figure, 1 is a belt, 2 is a belt that transmits most of the driving tension, and is made by twisting thin fibers at equal pitches (P
3 is a pulley on which the belt 1 is hung, 11 is a side surface of the belt that generates the transmission force, and 12 is the belt 1 that contacts the ■-shaped groove 31 of the pulley 3 to transmit the driving force. It is a contact surface.

Next, the operation will be explained.

The belt 1 is driven by frictional force from a capstan boob (not shown), and the belt contact surface 12 bites into the V-shape 71131 of the pulley 3 due to the belt initial tension and driving force, and due to the wedge effect, the belt contact surface 12 and V-shaped groove 3 of pulley 3
1 and generates a driving force to rotate a reel disk for tape winding.

[Problem to be solved by the invention]

Conventional reel drive belts have an oval shape as described above, so excessive tension acts on the core wire near the side of the belt, which generates a large frictional force between the belt and the boob groove, causing the core wire near the side of the belt to The belt angle becomes larger and the core wire itself stretches, deforming the belt and causing it to vibrate. In addition, the vibration of this belt is transmitted to the capstan shaft via the capstan pulley, worsening the feeding accuracy of the magnetic tape, deteriorating the image quality and sound quality of the video tape recorder, and causing problems such as the belt coming off. was there.

This invention was made to solve the above-mentioned problems, and aims to provide a reel driving belt that eliminates belt deformation, has less vibration, and is difficult to come off.

[Means to solve the problem]

The reel driving belt according to the present invention has a finer distribution density of cores in the belt side parts where the tension is high than in the center of the belt where the tension is low, or by changing the size and tensile strength, so that the tension per unit number can be increased. It is a balance of.

[Effect]

The reel driving belt of this invention eliminates deformation and vibration by making the distribution density of the core wires higher than the center of the belt in the part where the tension is high on the side of the belt and balancing the tension per core. decrease.

In addition, by changing the thickness and tensile strength of the core wire near the side of the belt, deformation can be similarly eliminated and vibrations can be suppressed.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In the figure, 1 is the belt, 2 is the core wire made of twisted thin fibers, and there is a fine pitch (Pl) near the side of the belt.
The center portion is arranged with a coarse pitch (P2). Note that the other configurations are the same as those of the above-mentioned conventional example, so explanations will be omitted.

Next, the effect will be explained.

The transmission path of the driving force is the same as that of the conventional example, but in the above example, the distribution density of the core wires 2 is higher in the belt side surface 11 where the tension increases than in the center of the belt, so that The tension of the core wire is balanced, and the core wire rotates the reel disk for winding the reel driving tape without generating excessive tension.

In the above embodiment, deformation of the belt is prevented by reducing the arrangement density of the core wires near the side surfaces of the belt, but the same effect can be achieved even if the thickness and tensile strength of the core wires are changed.

〔Effect of the invention〕

As described above, according to the present invention, deformation and vibration occurring in the reel drive belt can be easily reduced, making it possible to feed the magnetic tape with high precision and achieve high image quality and high sound quality. A video tape recorder can be obtained at low cost, and it is effective in preventing serious accidents such as belt coming off.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a reel driving belt according to an embodiment of the present invention, FIG. 2 is a sectional view of a conventional reel driving belt, and FIG. 3 is a view showing the state in which the belt is hung on a pulley. be. In the figure, 1 is a belt, 2 is a core wire, 3 is a pulley, eyes are a side surface of the belt, 12 is a contact surface of the belt, and 31 is a 7-shaped groove. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (3)

[Claims] (1) A reel drive belt that is incorporated in a part of the reel drive mechanism and is characterized in that its core wires are arranged at uneven pitches so that they are densely arranged near both sides and coarsely in the center. . (2) A reel drive belt characterized in that, in the core wire arrangement of the belt incorporated in a part of the reel drive mechanism, the core wires near both sides of the belt are relatively thicker than the center portion. (3) A reel drive belt characterized in that, in the core wire arrangement of the belt incorporated in a part of the reel drive mechanism, the tensile strength of the core wires near both sides of the belt is made stronger than that of the center line.