JPS6315633Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a roller drive device used as a tape transport device for audio tape or video tape equipment.

[Technical background of the invention]

Generally, this type of tape transport device is provided with a pair of shaft bodies each having a tape reel attached thereto.
Depending on the tape feeding direction, one of them is rotated in a predetermined direction for winding. For example, when feeding a tape from a reel attached to the right shaft to a reel attached to the left shaft, it is necessary to rotate the left shaft for winding. Further, when feeding the tape in the opposite direction, the right shaft must be rotated in the opposite direction, and the drive device is switched from the left shaft to the right shaft.

In this case, the drive device includes a roller that is integrally attached to each of the shafts, and a drive roller that receives rotational force from the motor and an idler that presses against the outer peripheral surface of the drive roller that is provided between these rollers. A configuration is used in which the idler is brought into pressure contact with one of the rollers. here,
The idler has one end rotatably fitted to the support shaft of the drive roller and is rotatably supported by the other end of a support plate whose longitudinal direction extends along the radial direction of the drive roller.
The idler is pivoted to the support plate so as to generate some frictional resistance against its rotation. Therefore, when the idler is not in contact with any of the shaft rollers mentioned above, when the drive roller rotates,
It revolves around the drive roller without rotating while remaining in contact with its outer peripheral surface. That is, it is displaced in an arc along the outer peripheral surface of the drive roller. Due to this revolution, when the idler comes into contact with any of the shaft body rollers, the revolution is stopped, and the idler rotates by overcoming the frictional resistance due to the rotational force of the drive roller, and rotates the shaft body roller that is in contact with the outer periphery of the idler. let

When rotating the shaft on the opposite side for winding, it is sufficient to reverse the rotational direction of the drive roller, rotate the idler in the opposite direction, and bring it into contact with the roller for the shaft on the opposite side.

In such a drive device, the support plate includes:
The hole that fits into the support shaft of the drive roller is configured as a long hole extending along the length direction of the support plate so that it can slide along the radial direction of the drive roller. Further, a tension spring is stretched between the support shaft of the drive roller and the support shaft of the idler.

The reason for this configuration is to avoid machining errors in the drive roller, idler, and rollers, dimensional errors between the axes of these supporting members, and deformation over time of elastic members such as rubber used in a part of the idler. This is to absorb the heat and keep the idler in contact with the drive roller and the shaft roller at all times in a favorable state.

[Problems with background technology]

However, in the above configuration, since the support shafts of the drive roller and idler are tensioned by a tension spring,
The support plate that supports this gap must have a strong structure that does not deform under the above tensile force, and must be made of a member that is stronger than necessary for the purpose of supporting the idler. No.

[Purpose of invention]

The purpose of this invention is to incorporate the spring that presses the idler against the drive roller into the supporting bearing plate together with the idler, thereby making the entire structure compact, and eliminating the need to use an unnecessarily strong member for the supporting bearing plate. Rather, the object is to provide a roller drive device that can be configured to be small and lightweight.

[Summary of the idea]

The roller drive device according to the present invention includes a drive roller that receives rotational force from a motor, and a bearing whose one end is rotatably fitted to the support shaft of the drive roller and whose other end is movable along the outer circumferential surface of the drive roller. a plate, an idler disposed such that its outer circumferential surface is in contact with the outer circumferential surface of the drive roller and using an elastic body on the outer circumferential surface, a first shaft portion rotatably fitted into the center of the idler, and the idler. an eccentric shaft having a second shaft integrally integrated in the length direction and rotatably fitted to the other end of the bearing plate, the first and second shafts being eccentric to each other; and the eccentric shaft. and a spring provided between the eccentric shaft and the bearing plate to provide a rotational force in a direction to bring the idler closer to the outer peripheral surface of the drive roller, and a spring provided at a position where it can come into contact with the outer peripheral surface of the idler and driven to rotate by contact with the idler. A spring provided between the eccentric shaft and the bearing plate presses the idler against the drive roller, and by using the eccentric shaft, the idler is separated from the outer peripheral surface of the drive roller by the amount of eccentricity. It is designed so that vibrations do not occur even in response to load fluctuations.

[Example of idea]

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

In FIGS. 1 and 2, reference numeral 11 denotes a drive roller, which is rotatably supported by a support shaft 12 and receives rotational force from a motor (not shown) through a belt 13. Reference numeral 15 denotes a bearing plate, one end of which is rotatably fitted onto the support shaft 12 of the drive roller 11. Further, its longitudinal direction is arranged along the radial direction of the drive roller 11, so that the other end can be displaced in an arc shape along the outer circumferential surface of the drive roller 11 around the spindle 12 of the drive roller 11. . 17 is idler,
A donut-shaped elastic body portion 17b made of rubber or the like is integrally fixed to the outer peripheral surface of a donut-shaped metal portion 17a. This idler 17 is rotatably held by an eccentric shaft 18, which will be described later, and is attached to the other end of the bearing plate 15 by the eccentric shaft 18 so that the outer peripheral surface formed by the elastic body portion 17b is in contact with the outer peripheral surface of the drive roller 11. Supported.

As shown in FIG. 3, the eccentric shaft 18 has a first shaft portion 18a into which the idler 17 is rotatably fitted.
and a second shaft part 18b which is integrated with the first shaft part 18a in the length direction and rotatably fits into the other end part of the bearing plate 15, A flange portion 18c is integrally provided between the two shaft portions 18a and 18b.

Here, in the eccentric shaft 18, the axis center a of the first shaft part 18a and the axis center b of the second shaft part 18b have a dimension c.
are arranged so that they are eccentric to each other.

20 is a tightening screw, which is attached to the first shaft portion 1 of the eccentric shaft 18;
As shown in FIG.
It is pressed against 8c. This is Idler 17,
This is because weak frictional resistance is generated against rotation about the first shaft portion 18a.

Reference numeral 23 denotes a coiled spring, which is fitted onto the upper part of the eccentric shaft 18. Its end is passed through a slot formed at the upper end of the eccentric shaft 18 and fixed, and the other end is fixed to the bearing plate 15.
It is inserted into the hole 15a formed in and fixed. Then, a rotational force is applied to the eccentric shaft 18 in a direction to bring the idler 17 attached to the first shaft portion 18a closer to (pressure against) the outer peripheral surface of the drive roller 11.

25 and 26 are rollers for rotating tape reel mounting shafts (not shown), and support shafts 27 and 28
The idler 17 is rotatably supported by the idler 17, and is arranged at a position where it can come into contact with the outer circumferential surface of the idler 17, with the drive roller 11 as the center.

In the figure, reference numeral 30 denotes an E-ring, which is attached to the support shaft 12, the eccentric shaft 17, and the support shafts 27 and 28, respectively, to prevent them from coming off.

In the above configuration, the idler 17 is now in contact with the right roller 26 shown in FIG. 1, or is not in contact with any of the rollers 25, 26. In this state, when the drive roller 11 is rotated clockwise as indicated by the arrow, the idler 17 that is in pressure contact with the outer periphery of the drive roller 11 is moved to the flange portion 1 of the eccentric shaft 18.
Due to the light frictional resistance against 8c, the roller 8c does not rotate and revolves in an arc shape toward the left in the figure while remaining in contact with the drive roller 11. Due to this revolution, when the outer peripheral surface of the idler 17 comes into contact with the outer peripheral surface of the roller 25, the idler 17 is prevented from revolution, and due to the rotational force of the drive roller 11, it overcomes the light frictional resistance and rotates in the direction of the arrow. The roller 25 in contact with the outer periphery is rotated in the direction of the arrow.

Here, a relatively large load is applied to the roller 25 on the idler 17 at the time of starting. Moreover, this load changes constantly thereafter. However, Idler 17
is supported by the eccentric shaft 18, and its eccentric dimension c
Since it has the degree of freedom to change its position, it is connected to the roller 25 and the drive roller 11 in a manner that corresponds to the above-mentioned load fluctuation.

For example, when the roller 25 is applied to the idler 17 as a relatively constant load, the idler 17 is pressed against the roller 25 by the pressure applied by the coiled spring 23 to the idler 17 via the eccentric shaft 18. Rotate. However, when an excessive load is momentarily applied to the idler 17, a force is generated in the idler 17 that bites between the roller 25 and the drive roller 11. In this case, the idler 17 can be displaced in the direction away from the drive roller 11 by its own elastically deformable dimension, so it joins the drive roller 11 and the roller 25 in a well-balanced manner and does not bite into them.

In this way, the elasticity of the idler 17 can be suitably utilized to transmit the optimum driving force to the roller 25, so that vibration between the drive roller 11 and the roller 25 can be suppressed.

In addition, in order to rotate the roller 26 on the opposite side, it is sufficient to rotate the drive roller 11 counterclockwise in the direction of the arrow in the state shown in FIG. be done.

[Effect of idea]

As described above, according to the present invention, the idler is attached to the tip of the bearing plate by an eccentric shaft so that it can revolve around the drive roller, and the spring for pressing the drive roller is mounted on the bearing plate together with the eccentric shaft. Since this is provided, the spring force applied to the bearing plate is small compared to a conventional structure using a tension spring, and it is sufficient to have sufficient strength to hold the idler, and each part is made smaller and lighter. Further, since the idler can be displaced relative to the drive roller by the eccentric dimension by the eccentric shaft, a good joint state can always be maintained even under overload, and no vibration occurs.

[Brief explanation of drawings]

1 and 2 are a plan view and a front view showing one embodiment of a roller drive device according to the present invention, and FIG.
The figure is a front view showing an example of the shape of the eccentric shaft used in the present invention. 11... Drive roller, 12... Support shaft, 15...
Bearing plate, 17... Idler, 18... Eccentric shaft, 1
8a...first shaft part, 18b...second shaft part, 2
3...Spring, 25, 26...Roller.

Claims (1)

[Scope of utility model registration request] A drive roller that receives rotational force from a motor, a bearing plate that has one end rotatably fitted onto a support shaft of the drive roller and whose other end is movable along the outer peripheral surface of the drive roller, an idler disposed such that its outer circumferential surface is in contact with the outer circumferential surface and using an elastic body on the outer circumferential surface; a first shaft portion rotatably fitted in the center of the idler; a second rotatably associated with the other end of the bearing plate;
an eccentric shaft having a shaft portion whose center axes of the first and second shaft portions are eccentric to each other, and an eccentric shaft provided between the eccentric shaft and the bearing plate to drive the idler with respect to the eccentric shaft on the outer circumferential surface of the roller. 1. A roller drive device comprising: a spring that applies a rotational force in a direction to bring the roller closer to the idler; and a roller that is provided at a position where it can come into contact with the outer peripheral surface of the idler and is rotationally driven by contact with the idler.