JPH04311862A - Tape guiding device - Google Patents

Abstract

PURPOSE:To miniaturize a tape guiding device and to make the device low cast by making a detent attached directly to a pedestal have the detent function of a guiding member. CONSTITUTION:This device is provided with the pipe-like guiding member 21 to gude a tape, an ultrasonic exciter 24 whose one end is a free end and the oter end is fixed to the guiding member 21 and to vibrate the guiding member 21 with a standing wave and a supporting shaft 19 to support the guiding member 21. A detent 14 pinching the ultrasonic exciter 24 is provided on the pedestal 23 where a supporting shaft 19 is attached.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape guide device suitable for application to, for example, a video tape recorder.

0002

2. Description of the Related Art Tape guide devices used in video tape recorders and the like can be broadly classified into rotating types and fixed types. The rotating type has the characteristic that it applies less running resistance to the tape. However, for example, uneven rotation of the bearings used may manifest as uneven running of the tape, or if the running direction of the tape is not perpendicular to the rotating direction of the rotating roller, the tape will receive force in the width direction from the roller. There were disadvantages such as receiving Particularly in the latter drawback, the tape further moves in the width direction,
Sometimes the edges of the tape were damaged. Therefore, when a rotary tape guide device is used, the accuracy of parts and assembly must be extremely high, making manufacturing difficult. On the other hand, the fixed type allows the tape to run stably, but has the drawback of high tape running resistance. For these reasons, there is a demand for a fixed type tape guide device with low tape running resistance, and an air guide is one example. This air guide is of a type in which air is ejected from small holes provided on the surface of the guide body to levitate the tape and reduce the running resistance of the tape. However, even with this air guide, new problems arise, such as the need for a compressor as an air source. In order to solve these drawbacks and problems, the present applicant has previously proposed an ultrasonic vibrating tape guide device using ultrasonic waves (Japanese Patent Application No. 103627/1999). This ultrasonic vibrating tape guide device is designed to reduce tape running resistance while maintaining fixed tape running stability. Furthermore, the height of this ultrasonic vibration tape guide device is adjustable. This ultrasonic vibrating tape guide device will be described below with reference to FIG. 4.

In FIG. 4, reference numeral 5 denotes a main shaft mounted on a base 18. The guide member 2 to which the ultrasonic vibrator 3 is fixed is supported by a cylindrical support shaft 7 made of brass and having a support protrusion 7b. Lower and upper flanges 9 and 10
are arranged so as to come into contact with the upper and lower ends of the support shaft 7, and serve to guide the edge portion of the tape wound around the guide member 2. The main shaft 5 is configured to pass through the lower and upper flanges 9 and 10 and the support shaft 7. Reference numeral 6 denotes a height adjustment screw that is fitted into the inner periphery of the upper end of the support shaft 7 and is screwed into a screw 23 formed at the end of the main shaft 5. 8 is a mounting member, and this mounting member 8
An upper flange 10 is fixed to the upper part of the mounting member 8 with mounting screws 15, and a lower flange 9 is fixed to the lower part of this mounting member 8 with fixing pins 22 and 24. As shown in FIG. 5, the element housing portion 8a of the mounting member 8 has side walls 8b on both sides.
It is constructed by forming a hole in the shape of a rectangular parallelepiped, and a stopper fitting hole 8c is formed in both side walls 8b of the hole.

A locking protrusion 39a of a disc-shaped stopper 39 made of rubber is fitted into the stopper fitting hole 8c.
By holding the ultrasonic vibrator 3 between the stoppers 39, rotation of the guide member 2 is prevented. The attachment member 8 serves to keep the lower and upper flanges 9 and 10 parallel, and to keep the distance between them approximately 0.1 mm larger than the length of the guide member 2. As shown in FIG. 4, the lower flange 9 is pushed upward by the biasing force of a coil spring 35 disposed around the outer periphery of the main shaft 5 between the lower flange 9 and the base 18. A pin insertion hole 20 is formed in the base 18 , and a fixing pin 22 erected on the lower surface of the lower flange 9 is inserted into this insertion hole 20 . In such a configuration, when the height adjustment screw 6 is rotated, the height of the guide member 2 can be adjusted by and against the biasing force of the coil spring 35. FIG. 6 shows the state of standing wave vibration generated in the guide member 2 by applying an alternating current voltage to the ultrasonic vibrator 3 and expanding it along the line XX. As shown in FIG. 10, the dotted line NN is a node, and the amplitude is zero on this line. If the distance from the end surface of the guide member 2 to the position of the node is n, the position of the support protrusion 7b in the axial direction is provided at a distance of n from the end surface of the guide member 2.

[0005]

As is clear from the above, in the above example, the lower and upper flanges 9 and 10 are kept parallel, and the distance between them is kept approximately 0.1 mm larger than the length of the guide member 2. Therefore, a highly accurate mounting member 8 was required, and the lower and upper flanges 9 and 10 were not circular as shown in FIG. 7, making manufacturing difficult. Therefore, there is a problem in that it is not possible to reduce the size and cost of the tape guide device.

[0006] The present invention has been made in view of the above points, and it is an object of the present invention to propose a tape guide device that can be made smaller and lower in price.

[0007]

[Means for Solving the Problems] As shown in FIGS. 1 to 3, for example, the tape guide device of the present invention includes a pipe-shaped guide member 21 for guiding a tape, one end of which is a free end, and the other end of which is a guide member 21. In the tape guide device 17, which includes an ultrasonic vibrator 24 that is fixed to the ultrasonic vibrator 24 and vibrates the guide member 21 with standing waves, and a support member 19 that supports the guide member 21, an ultrasonic wave is applied to the base 23 on which the support member 19 is attached. A detent 14 is provided to clamp the vibrator 24.

[0008]

[Operation] According to the present invention described above, since the detent 14 for holding the ultrasonic vibrator 24 is provided on the base 23 to which the support member 19 is attached, the number of parts can be reduced and the mechanism can be simplified. It is possible to reduce the size and cost of the device.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the tape guide device of the present invention will be described in detail below with reference to FIG. In FIG. 1, reference numeral 23 denotes a base, and the main shaft 11 having a threaded portion 26 formed at its tip portion is attached to the base 23 in an upright manner. A coil spring 27 is disposed through this main shaft 11, and this main shaft 1
1 through the lower flange 12b and placed on this coil spring 27. Reference numeral 19 denotes a cylindrical support shaft, and a recess 19b is provided around the support shaft 19 at a distance n from each end of the support shaft 19, and a support ring 25 made of resin, for example, is inserted into the recess 19b.
Insert. Reference numeral 21 denotes a cylindrical guide member. The support shaft 19 is inserted into this guide member 21, and the guide member 21 is supported by the support ring 25 of the support shaft 19. Reference numeral 24 denotes an ultrasonic vibrator, and the front end surface of the ultrasonic vibrator 24 is bonded to a predetermined position of the guide member 21, for example. The length of this guide member 21 is made longer than the length of this support shaft 19 by, for example, 0.1 mm. The guide member 21 supported by the support ring 25 of the support shaft 19 is inserted into the main shaft 11, and the upper flange 12a is passed through the main shaft 11 so that the upper flange 12a is arranged on the guide member 21. Further, as shown in FIG. 6, the upper flange 12a and the lower flange 12b are each made circular. Further, the threaded portion 26 of the main shaft 11 and the height adjustment screw 16 are screwed together, and the height adjustment screw 16 is rotated to move the upper flange 12a downward.
That is, it is rolled down toward the base 23 side.

Reference numeral 14 denotes a rotation stopper, and the rotation stopper 14 is formed integrally with the base 23. Further, as shown in FIG. 2, a recess 14a is formed in the upper part of the detent 14,
The ultrasonic vibrator 24 attached to the guide member 21 is held in this recess 14a. At this time, the ultrasonic vibrator 24 is made to enter the recess 14a by, for example, about 3 mm.

When the height adjustment screw 16 is rotated, the height of the tape guide device 17 can be adjusted by or against the biasing force of the coil spring 27. The height adjustment range is about 0.5 mm, and the ultrasonic vibrator 24 is set to enter the recess 14a of the detent 14 by about 3 mm, so even if the height is adjusted, the ultrasonic vibrator 24 will not detent. 1
It never goes beyond 4.

Now, in the tape guide device having such a structure, when an alternating current voltage at the resonant frequency of the guide member 21 is applied to the ultrasonic vibrator 24, a standing wave is generated in the guide member 21. As a result, the tape guide device 1
When the running of the tape is guided by 7, the coefficient of friction is reduced to a fraction of that when no alternating voltage is applied. The state of the standing wave generated on the guide member 12 is as shown in FIG. established in As is clear from the above, in this example, the rotation prevention function of the guide member 21, which was the role of the mounting member 8, is achieved without using the highly accurate mounting member 8 as explained in FIG. Since it is held by the detent 14 directly attached to the base 23, the tape guide device can be made smaller and less expensive.

It goes without saying that the present invention is not limited to the above-described embodiments, and that various other configurations can be adopted without departing from the gist of the present invention.

[0014]

According to the present invention described above, the base to which the support member is attached is provided with a detent for holding the ultrasonic vibrator, so the number of parts can be reduced and the mechanism can be simplified.
There is an advantage that the device can be made smaller and lower in price.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the tape guide device of the present invention.

FIG. 2 is a diagram showing an embodiment of the tape guide device of the present invention.

FIG. 3 is a top view showing an embodiment of the tape guide device of the present invention.

FIG. 4 is a sectional view showing an example of a conventional tape guide device.

FIG. 5 is a plan view showing an example of a conventional tape guide device.

FIG. 6 is a graph for explaining a conventional tape guide device and a tape guide device of the present invention.

[Explanation of symbols]

14 Stop rotation 17 Tape guide device 19 Support shaft 21 Guide member 23 Base 24 Ultrasonic vibrator

Claims (1)

[Claims] 1. A pipe-shaped guide member that guides a tape; an ultrasonic vibrator having one end set as a free end and the other end fixed to the guide member and vibrating the guide member with standing waves; and the guide member. 1. A tape guide device comprising a support member for supporting the ultrasonic vibrator, characterized in that a base to which the support member is attached is provided with a detent for holding the ultrasonic vibrator.