JPS6366751A - Magnetic tape guiding roller - Google Patents

Abstract

PURPOSE:To obtain a magnetic tape guiding roller produced at low cost, where the runout of a rotary body is less and which can stand high speed rotation and can be used for a long time, by splicingly guiding a magnetic tape on the peripheral part of the rotary body and guiding the end part of the magnetic tape in a guide part. CONSTITUTION:The rotary body 2 made of resin material is held in order to freely rotate by applying lubricating oil 5 on a fixed shaft 4 and on both ends the recessed parts 2a and 2b whose diameters are shorter than an outer diameter are formed. And on both end parts shaft of the rotary body 2 two guiding part 1 and 3 fixed on the fixed 4 are provided, which have projections 1a and 3a formed in order to fit the recessed parts 2a and 2b of the rotary body 2 with specified clearances respectively. Thus through the roller made of resin material produced at low cost is used, the tape guiding roller whose rotation sound is low and rotation runout is small and which has a long life is obtained at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic tape guide roller used in a magnetic recording/reproducing device such as a video tape recorder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a tape pull-out device of a conventional magnetic recording/reproducing apparatus and a magnetic tape guide roller used therein will be explained with reference to conventional technical drawings. FIG. 2 shows a schematic configuration of a magnetic recording/reproducing apparatus. 11 is a chassis; 12 is a cassette having a supply reel 13 and a take-up reel 14; The magnetic chi 115 wound around the supply reel 13 exits the cassette 12 via the guide post 17 and the guide post 18, and is transferred to the tensitan post 19. Erase head 2° impedance roller 21. A guide roller 22° is attached to the guide post 23 and wound around the rotating head cylinder 24.
Guide boss 25. Guide roller 26, impedance roller 28. Go to voice/control 29. Guide post 30. Capstan 32. It passes through the pinch roller 31, enters the cassette 12, passes through the guide post 16 in the cassette, and is taken up by the take-up rule 14.

The dashed line 27a indicates the guide roller 22. Guide boss 23
W22a when is in the cassette opening.

This is a trajectory from 23a to a predetermined movement position.

The one-dot chain line 27b also corresponds to the guide post 25. This is the trajectory of the guide roller 26.

Here, guide rollers 22, 26, guide boss 23.
Pay attention to 25. FIG. 3 is a partially enlarged perspective view of the guide post 25 and the guide roller 26. FIG.

The holder 40 has boss portions 40a and 40b. The inclined guide post 25 is press-fitted into the boss portion 40b, and the lock post 26e is press-fitted into the boss portion 40a.

FIG. 4 is a partial sectional view of the vicinity of 266 (al is lock post). The lock boss 26e press-fitted into the boss portion 40a is provided with a female threaded portion at one end to engage with a male threaded portion provided on the lower guide 26d of the guide roller 26, and the other end of the lock boss 26e is provided with a female threaded portion to engage with a male threaded portion provided on the lower guide 26d of the guide roller 26. It has a cylindrical hole into which the fixed central shaft 26f of the roller 26 is inserted.

An upper guide 26b and a lower guide 26d are press-fitted and fixed to the central shaft 26 with a predetermined gap therebetween. Upper guide 26b
The upper end of has a groove 26C. 26a is a roller generally made of resin such as polyacetal, and the center shaft 26
It is rotatably supported by f. The magnetic tape 15 is moved by the roller 26a during or when the tape is being drawn out.
and is regulated by the upper guide 26b and lower guide 26d. When a jig such as a screwdriver is inserted into the groove 26C of the upper guide 26b and rotated around the central axis 26f, the male screw of the lower guide 26d and the lock post 26e are connected.
The upper guide 25b and the o-ra 26
a. The lower guide 26d moves up and down with respect to the lock boss 26e.

The magnetic tape guide roller with the above configuration is a very small post unit, and it can also be used to regulate the vertical direction of the magnetic tape.
This allows for vertical adjustment.

Further, as another conventional example of the tape guide roller, a configuration example particularly suitable for high-speed rotation will be described.

The one shown in FIG.
In this model, oil-impregnated metals 42 and 45 are press-fitted into the upper guide 41 and lower guide 45, respectively.

The oil-impregnated metal 42.45 supports the upper and lower ends of a hollow shaft 44 that is integrally formed with the roller 43.
This was an attempt to improve the high-speed performance of the guide roller by using fixed oil-impregnated metal.

411afc) shows a roller 53 supported by ball bearings 52 and 54, which is a generally considered configuration when the purpose is to improve high-speed performance.

Problems to be Solved by the Invention The conventional techniques described above have the following drawbacks.

(1) When the rollers are rotated at high speed, they tend to generate harsh abnormal noises that can be discerned even during normal use.

(2) Particularly when a resin roller is rotated at high speed, the wear of the roller increases the play between it and the shaft. This results in an increase in so-called jitter, which causes vibrations in the
This will seriously affect the image quality.

(3) When oil-impregnated metal is used, it tends to be expensive as it requires high-precision oil-impregnated metal machining and a high-precision hollow shaft, and the lubricating oil contained in the oil-impregnated metal scatters during the rotation of the roller. Easy to adhere to magnetic tape.

(4) It is relatively easy to improve high-speed performance with a structure using ball bearings, but it requires the use of high-precision ball bearings, which makes the cost extremely expensive, and The rolling sound of the rotating balls is also loud.

The present invention aims to solve these conventional problems and provides a guide roller suitable for high-speed rotation at low cost.

Means for Solving the Problems In order to solve the above problems, the magnetic tape guide roller of the present invention has a rotary body made of a resin material rotatably supported on a fixed shaft with lubricating oil interposed therebetween, and a rotor at both ends thereof. A convex portion or a concave portion having a smaller diameter than the outer diameter is formed, and the rotating body is fixed to the fixed shaft at both ends of the rotary body, and is formed to fit into the convex portion or the concave portion of the rotary body with a predetermined clearance, respectively. The guide portion is provided with two guide portions each having a concave portion or a convex portion.

Effect of the Invention With the above-described configuration, the present invention can provide a tape guide roller with low rotational noise, small rotational runout, and long life at a low cost while using a roller made of a resin material that can be manufactured at low cost.

EXAMPLE Hereinafter, an example of the magnetic tape guide roller of the present invention will be described with reference to the drawings. FIG. 1 (al) shows a sectional view of a main part of an embodiment of the magnetic tape guide roller of the present invention. It is rotatably supported while being lubricated by 5.

Further, a recess 2a having a smaller diameter than the outer diameter of the rotor 2 is formed at the upper end of the rotor 2, and a recess 2b having a smaller diameter than the outer diameter of the rotor 2 is similarly formed at the lower end. Reference numeral 1 denotes an upper guide which is press-fitted onto the fixed shaft 4 at the upper end of the rotating body 2 and has an outer diameter larger than that of the rotating body 2 . Further, a convex portion 1a is formed which fits into the concave portion 2a of the rotating body 2 with a predetermined clearance. Similar to the upper guide 1, an upper guide 2 is press-fitted onto the fixed shaft 4 at the lower end of the rotating body 2, and has an outer diameter larger than the outer diameter of the rotating body 2. A convex portion 3a is formed which fits into the concave portion 2b of the rotating body 2 with a predetermined clearance. 7
is a male thread formed on the lower guide 3, and is provided to engage with a female thread formed on the lock post 26e as explained in the conventional example of FIG. With this configuration, the magnetic tape 15 is guided along the outer circumferential surface of the rotating body 2, as shown in FIG. Furthermore, the rotating body 2 and the lower guide 3 are in contact with each other at the recess 2b, which has a smaller diameter than the outer diameter of the rotating body 2, and at the end face of the lower guide 3a. Sliding is stable,
Even when the rotating body 2 rotates at high speed, generation of unpleasant abnormal noise can be suppressed.

Further, the presence of the lubricating oil 5 allows the rotating body 2 to rotate stably, but since the concave portions 2a, 2b and the convex portions la, 3a are formed, even when the rotating body 2 rotates at high speed, the outer circumferential portion The lubricating oil 5 does not scatter, and the recesses 2a and 2b
By appropriately setting the clearance between the corresponding protrusions la and 3a, the lubricating oil 5 is held by surface tension, and the effect of preventing scattering can be enhanced.

A second embodiment is shown in FIG. 1 (1). Rotating body 2
A recess 2a having a smaller diameter than the outer diameter of the rotating body 2 is formed at the upper end of the
A convex portion 2C is formed at the lower end. This concave portion 2a and convex portion 2
A convex portion la is formed on the upper guide 1, and a recessed portion 3b is formed on the lower guide 3 so as to fit with each of C with a predetermined clearance.
This is provided. And concave part 2a, convex part 2C1 convex part 1a,
Both of the recesses 3b are configured to have a tapered shape.

It goes without saying that the same effect as shown in FIG. 1 (3) can be obtained with such a configuration, but by making the upper end of the rotating body 2 a concave part and the lower end a convex part, the lubricating oil 5 can be scattered around the outer periphery. This effect is particularly noticeable in stationary magnetic recording and reproducing devices that use magnetic tape guide rollers in the posture shown in Figure 1 (bl). The concave portions 2a and convex portions 2C of the body 2 are tapered, making it possible to form a template for molding such as injection molding without difficulty, and even if the concave portions 2a and convex portions 2C are formed, there will be no problem in terms of strength. (It is possible to obtain a highly accurate rotating body.)

A third embodiment is shown in FIG. 1+c+. By changing the shapes of the recesses 'la and 'lb at the upper and lower ends of the rotating body 2 and the corresponding convex parts of the upper guide 1 and lower guide 3, the scattering distance of the lubricating oil 5 to the outer periphery of the rotating body 2 is increased. This improves the sealing effect of the lubricating oil 5. In addition, in this embodiment, when the diameter of the central cylindrical hole of the rotating body 2 is dl, the diameter of the cylindrical holes at the upper and lower ends of the rotating body 2 is d2, and d,<d
It is set so that it becomes 2. In other words, when the hole diameter of the rotating body 2 is d, the lubricating oil 5 has a good lubrication condition due to the clearance formed between it and the fixed shaft, and at the same time, the lubricating oil 5 is held in this clearance by its surface tension. It is set. On the other hand, in the part where the hole diameter is d2, the clearance is large (the lubricating oil 5 is not retained. As a result, the chance of the lubricating oil 5 scattering to the outer peripheral surface of the rotating body 2 is reduced. .

Effects of the Invention As is clear from the above description, the present invention includes a fixed shaft, a lubricating oil interposed on the fixed shaft, rotatably supported, and a convex or concave portion having a smaller diameter than the outer diameter of the outer periphery at both ends of the fixed shaft. A rotating body made of a formed resin material, and a convex portion or a concave portion of the rotating body, which has a diameter larger than the outer diameter of the outer circumference of the rotating body and is fixed to the fixed shaft at both ends of the rotating body. and two guide parts each having a concave part or a convex part formed to fit with each other with a predetermined clearance, the magnetic tape is attached and guided to the outer peripheral part of the rotary body, and the guide part By guiding the end of the magnetic tape, the configuration can be realized at a very low cost, but it has less center runout of the rotating body, can withstand high-speed rotation, and also prevents abnormal tongue wear during long-term use. This provides an excellent effect of providing a highly practical magnetic tape guide roller that does not cause increased runout or abnormal noise. As a result of this effect, magnetic recording and reproducing devices can perform fast forwarding and rewinding while pulling out the tape and keeping the tape wrapped around the rotating head cylinder. Although there was a problem that the driving force was extremely large, a great effect can be obtained in that it can be carried out without such problems.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a magnetic tape guide roller of the present invention, FIG. 2 is a schematic configuration diagram of a magnetic recording and reproducing device,
Figure 3 is a partially enlarged perspective view of the guide post in Figure 2;
The figure is a sectional view of a main part of a conventional magnetic tape guide roller. l...Top guide, 2...Rotating body, 3.
...Lower guide, 4...Fixed shaft, 2a, 2
b... Concavity of rotating body, 2C... Convex part of rotating body, la, 3a... Convex part of guide, 3b.
... Guide recess, 5 ... Lubricating oil. Name of agent: Patent attorney Toshio Nakao

Claims (3)

[Claims] (1) A fixed shaft, a rotating body made of a resin material that is rotatably supported by the fixed shaft with lubricating oil interposed therebetween, and has a convex or concave portion with a diameter smaller than the outer diameter of the outer circumference formed at both ends; It has a diameter larger than the outer diameter of the body, is located at both ends of the rotating body, fixed to the fixed shaft, and is formed to fit into a convex portion or a concave portion of the rotating body with a predetermined clearance, respectively. 2 with a concave or convex portion
1. A magnetic tape guide roller, comprising: a magnetic tape guide roller attached to an outer circumferential portion of the rotating body, and configured to guide an end portion of the magnetic tape with the guide portion. (2) Claim (1) characterized in that the convex portion or concave portion of the rotating body and the concave portion or convex portion of the guide portion that fits into the convex portion or concave portion of the rotating body are formed in a tapered shape. Magnetic tape guide roller as described. (3) The upper end of the rotating body is a concave portion and the corresponding guide portion is a convex portion, and the lower end of the rotating body is a convex portion and the corresponding guide portion is a concave portion.
) or (2).