JPH0711877B2 - Idler equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to transmission of rotational force from a driving body to a driven body by movement thereof, which is used in, for example, video and audio tape recorders and other machines. Relates to an idler device for switching a non-transmission state.

2. Description of the Related Art Conventionally, as a device of this type, for example, in a video tape recorder (VTR), when a plurality of outputs are obtained from a single motor in order to reduce the number of motors used as driving sources and to reduce the cost and weight. There is. If the motor is a capstan motor that should be used to drive the tape at a normal constant speed, in order to wind the tape from the capstan with an appropriate tape tension by the take-up reel during recording and reproduction. The transmission ratio of the rotation transmission system from the capstan to the take-up reel stand is set so that the take-up tangential speed is slightly higher than the take-up speed by the capstan. Further, a clutch is interposed in the process of this rotational force transmission system to generate this appropriate tape tension. The rotation transmission force of the clutch in this case is set so as to simply generate a low tape tension that winds the tape from the capstan without slackening. On the other hand, when winding or rewinding the tape at high speed, it is necessary to rotate the capstan at high speed and wind the tape with a sufficiently high tape tension to withstand the load of the tape path. There is. Therefore, it is necessary to form a second rotational force transmission system that transmits the rotational force of the capstan to the reel stand directly or via a clutch having a high rotational transmission force. That is, when a capstan motor is used as a single drive source, it is necessary to configure a plurality of rotational force transmission systems, although there are the above-mentioned advantages. Further, an idler device is provided on the take-up or supply reel base in order to switch and wind the tape by switching the tape in the take-up or rewinding direction as required, and to switch the driving force transmission path from the drive source. As a concrete example of this idler device,
There is one disclosed in Japanese Patent Publication No. 73134. That is, description will be given with reference to FIG. 8 which is a side view showing the main part thereof. Reel stand 10
Reference numeral 0 denotes a gear portion 100a, which meshes with a relay gear 101 and is axially supported by shafts 102 and 103 which are raised on a substrate 104, respectively. On the other hand, the driving rotational force of the motor 105 fixed to the substrate 104 is generated by the belt 107 hung on the pulley 106.
It is transmitted to a pulley 109 which is rotatably supported by a shaft 108 which stands upright at 4. An idler holder 11 is provided above the shaft 108 of the pulley 109.
The idler holder 110 pivotally supports an idler 114 that meshes with a gear portion 109a of the pulley 109 by a shaft 111. A hysteresis plate 112 made of a soft magnetic material is fixed to the idler holder 110, and a ferromagnetic material portion 113 is integrally incorporated in the idler 114 at a position facing it. Further, the idler holder 110 normally engages with an idler controller 115 which is rotatably supported by a shaft 116 which is raised on the substrate 104, so that the relay gear 101 and the idler 114 do not mesh with each other when unnecessary. The moving position is restricted.
In such a configuration, the pulley 109 rotates with the rotation of the motor 100 to rotate the idler 114.
The idler 114 receives a rotational load due to a change in magnetic flux between the ferromagnetic material portion 113 and the hysteresis plate 112, and the idler holder 110
Rotational force is generated to rotate both. Normally, it is regulated by the idler controller 115, but when the regulation is released, the idler 114 rotates in the rotation direction of the pulley 109 and meshes with the relay gear 101 on the winding or supply side and from the motor 105 to the reel stand 100. To form a rotation transmission system. Although not shown, a felt clutch is provided between the idler holder 110 and the idler in place of the ferromagnetic body portion 113 and the hysteresis plate 112 shown in FIG. 8 to provide an elastic body that presses each other by friction force with the clutch felt. In some cases, the idler 114 is configured to rotate together with the idler holder 110.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described above, in controlling the contact and separation of the idler with the reel base or the rotational force transmission means to the reel base, the clutch felt is conventionally attached to the rotary drive body. The idler holder is pressed by an elastic body via the idler holder and the idler holder is rotated by the frictional force with the clutch felt to rotate the idler supported by the idler holder, or it is fixed between the idler and the idler holder. This was done by providing a ferromagnetic material portion and a hysteresis plate. However,
In order to configure multiple rotational force transmission systems with different rotational transmission force from a single drive source, multiple clutch mechanisms are required and the configuration becomes complicated. This is a major factor that requires space and limits the miniaturization of the device itself, or becomes extremely thick when they are formed by stacking them on a substrate, and restricts the device to be ultrathin.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide an idler device that can be made ultrathin and miniaturized.

Means for Solving the Problems The present invention relates to a rotary drive unit including at least a ferromagnetic member, and a reel base or a rotational force transmission member for the reel base that is constantly engaged with the rotary drive base. , The first and the second which are separated from each other and constitute a part of the first or the second rotational force transmission system, respectively.
An idler, and first and second idler holders made of a soft magnetic material that axially support the first or second idler and have the same rotation center as the rotation drive unit and face each other via the rotation drive unit. , A first engaging member which engages with the first or second idler holder, and controls contact and separation of the first or second idler with the reel base or a rotational force transmitting member on the reel base. , An idler device having a second idler controller.

Effect The present invention makes it possible to realize an ultra-thin and miniaturized structure with an extremely simple structure when transmitting the rotational driving force from a single drive source to the reel stand via a plurality of rotation transmission systems with the above configuration. The present invention provides an idler device that does.

Example Hereinafter, an example according to the present invention will be described in detail.
FIGS. 1 to 5 show an embodiment according to the present invention, and FIGS. 3, 4 and 5 show tapes (not shown) mounted on the take-up reel base 16 and the supply reel base 17. ) Is a plan view of a rotational force transmission system that rotationally drives a reel (not shown) on which (1) is wound, and shows stop, high speed, and low speed transmission modes, respectively. FIG. 2 is a partially exploded perspective view, and FIG. 1 is a schematic side view. In FIG. 3, a capstan motor 1 is fixed to a substrate 28, and a capstan gear 3 is press-fitted into a capstan 2 which is coaxially formed with the capstan motor 1. A relay gear 4 meshes with the capstan gear 3 and further, via relay gears 5, 6 and 7 rotatably provided on a substrate 28, respectively, a center shaft 26 supported by a center shaft 26 raised on the substrate 28. The torque of the capstan motor 1 is transmitted to the gear 8. A second idler 12 meshes with the center gear 8 and a first idler 11 meshes with the small diameter portion 8a. On the other hand, the take-up reel stand 16 and the supply reel stand 17 are rotatably provided with respect to the high-speed reel stand gear part 33 and the take-up reel stand 16 and the supply reel stand 17 which are press-fitted and integrated as shown in FIG. The low-speed reel base gear part that is pressed against the high-speed reel base gear by an elastic body (not shown) via the clutch felt 34.
35 are provided. In addition, the low speed reel stand gear section 35,
Corresponding to the take-up and supply reel bases 16 and 17, respectively, a first take-up relay gear and a first supply relay gear 13, which are axially supported by a shaft 15 raised on a substrate, mesh with each other to form a high-speed reel base gear. Part 33
The second take-up relay gear 14 or the second supply relay gear 37 is meshed therewith. The main rod 25 is provided in the groove 15a of the shaft 15.
Are engaged with each other in the long groove portion 25a so as to be slidably guided in the left and right directions in FIG. 3, and the first and second take-up relay gears.
13, 14 and first and second supply relay gears 36, 37, 13, 14
It also serves to prevent the shaft 15 from coming off.

The rotational force of the capstan motor shown in FIG. 3 is generated by the first idler rotating around the center gear 8 and meshing with the first take-up relay gear 13 or the first supply relay gear 36. A first rotational force transmission system from the motor to the supply or take-up reel stand 16 or 17 is constituted, and the second idler is rotated so that the small diameter portion 12a is the second take-up relay gear or the second supply relay. Gear 3
By engaging with 7, a second rotational force transmission system for supplying from the capstan motor or the take-up reel stand 16 or 17 is constituted. 1 and 2, the center gear 8 has a boss portion 32 made of a material having lubricity with the center shaft 26 and a magnet portion (ferromagnetic material portion) 31 magnetized in the axial direction. The first idler holder 9 is made of a soft magnetic material and supports the first idler 11 by a shaft 29.
And a second idler is supported by a shaft 30 and magnetically sandwiched by a second idler holder 10 also made of a soft magnetic material. A bent portion 9b is provided at one end of the first idler holder 9, and its tip is close to the second idler holder 10 as shown in FIG.
This magnetic flux is configured to form a substantially closed magnetic circuit between the first and second idler holders 9 and 10 and the magnet portion 31. Therefore, the rotation of the center gear 8 causes a force to rotate both the first and second idler holders 9 and 10 in the rotation direction, and at the same time, to rotate the first and second idlers 11 and 12 axially supported by them. On the other hand, the first idler controller 18
Is rotatably supported by a shaft 24, and the cutout portion 18a engages with the groove portion 26a of the center shaft 26 as shown in FIG. 1, and the first idler holder 9, the center gear 8 and the second idler holder 10 are engaged. Of the main gear 25 and the cam projection 25c (see FIG. 5) of the main rod 25 which is guided by the shaft 15 by controlling the turning height of the first idler controller. The contact height is guaranteed. Further, the rotation restricting portion 18b of the first idler controller 18 is provided with the second idler when it is necessary to prevent the rotation of the first idler in the stop mode shown in FIG. 3 or the high speed transmission mode shown in FIG.
The function is achieved by contacting the bent portion 9b of the first idler holder 9 shown in the figure. And the first
The idler controller 18 has a coil portion inserted into the shaft 24, one end of which is raised by the first idler controller 18 and the other end of which is raised by the second idler controller 19, and is engaged with the shaft 22 which penetrates the elongated hole portion 21a of the link plate 21. The elastic body (torsion coil spring) 23 which is engaged with the first idler holder 9 urges the first idler holder 9 to rotate clockwise, that is, clockwise in FIG. The second idler plate 10 is a link plate 2 which is inserted into the shaft 21 which is raised as shown in FIG.
It is engaged with the second idler controller 19 via 1. The second idler controller 19 is rotatably supported by a shaft 27 raised on a substrate 28, and is urged to rotate counterclockwise by an elastic body 23. Thereby the link plate 20
The second idler holder 10 is urged in a predetermined direction away from the center thereof via the through hole to prevent the second idler 12 from rotating in the stop mode shown in FIG. 3 or the low speed transmission mode shown in FIG. It is a thing. Here, the elastic body 23 can be assembled very easily by holding both ends of the elastic body against the urging force, simply inserting the shaft 24 into the shaft 24 and then releasing the shaft 24 from the upper portion. On the other hand, the main rod 25 is provided with a rack portion 25d, which meshes with a pinion gear 26 which is rotated by a drive source (not shown) on the board 28, and by movement, a cam portion 19a of the second idler controller 19. A cam pin 25a is provided on the back surface at a position where it engages with.

The operation of the above configuration will be described. In the stop mode shown in FIG. 3, the first and second idler controllers
18 and 19 are urged by the elastic body 23 without being rotated by the main rod 25, respectively, and prevent the first and second idler holders 9 and 10 from rotating, respectively. Holds the state of FIG.
In the high-speed transmission mode that forms the second rotational force transmission system shown in FIG. 4, the main rod 25 moves rightward in the figure by the pinion 26, and the first idler controller 18 does not rotate at all, but the cam pin 25a does not rotate. The second idler controller 19 rotates in the clockwise direction in the drawing against the biasing force of the elastic body 23 by abutting on the cam portion 19a. Thereby, the link plate 21 engaged with the shaft 22 is released from the tension by the elastic body 23, and at the same time, the capstan motor rotates at a high speed, and the center gear 8 rotates in the counterclockwise direction, for example. As a result, the second idler holder 10 is rotated together with the link plate 21 and the second idler 12 as shown in FIG. 4 by the magnetic attraction force of the magnet 31 as described with reference to FIG. The small diameter portion 21a of 12 and the second winding relay gear 14 are meshed with each other to transmit the rotational force to the winding reel base 16. When the capstan motor 1 rotates in the opposite direction and the center gear 8 rotates in the clockwise direction in the figure, the second idler rotates in the clockwise direction as indicated by the alternate long and short dash line in the figure and similarly the supply reel base is rotated. A rotational force transmission system to 17 is formed. Next, in the low speed mode in which the first rotational force transmission system shown in FIG. 5 is formed, the main rod 25 further moves, and the cam portion 19a of the second idler controller 19 and the cam pin 25a are disengaged from each other. Idler controller 19 is third again
At the position shown in the figure, that is, the elastic body 23 prevents the second idler 12 from rotating. On the other hand, the second idler controller 18 is rotated counterclockwise by the cam portion 25c of the main rod 25, the contact with the bent portion 9a of the first idler holder 9 is cut off, and the first idler holder 9 is rotated. Release the operation prohibition state. Then, for example, when the capstan motor 1 rotates at a low speed and the center gear 8 rotates counterclockwise with it, the first idler holder 9 is driven by the magnet 31 of the center gear 8 on the same principle as described with reference to FIG. Rotates in the counterclockwise direction together with the first idler 11, and the first idler 11 meshes with the first winding relay gear 13. The rotational force is transmitted to the take-up reel stand 16 from the low-speed reel stand gear portion 35 of the take-up reel stand 16 meshing with the first take-up relay gear 13 via the clutch felt 34. Further, when the center gear 8 rotates in the clockwise direction in the opposite direction, the first idler 11 rotates to the position shown by the alternate long and short dash line in FIG. 5 to form the first rotational force transmission system to the supply reel base 17.

Even if these first or second idlers 11 and 12 rotate, the tip of the bent portion 9b of the first idler holder 9 always faces the second idler holder 10 as shown in FIGS. 4 and 5. However, the magnetic flux generated by the magnet 31 shown in FIG. 1 forms a substantially closed magnetic path, and as a result, the rotation of the first and second idler holders 9 and 10 is sufficient even if the thickness of the ferromagnetic material is thin. The driving force can be obtained and the mechanism can be made thinner. FIG. 6 is a side view showing a second embodiment according to the present invention, and basically the same components as those shown in FIG. 1 are designated by the same reference numerals for easy understanding. FIG. 6 shows that the gear portion 8a of the center gear 8 is made of a ferromagnetic material and is made of a material having lubricity with respect to the center shaft 26, in contrast to the ferromagnetic material portion 31 shown in FIG. The center gear 8 can be simplified in structure because it has the boss portion 38 that is formed. FIG. 7 shows a third embodiment according to the present invention, and the way of coding is the same as in FIG. FIG. 7 shows an idler shaft 29 for axially supporting the first idler 11 and the second idler 12, respectively, without providing a proximity portion by the bent portion 9b between the first and second idler holders 9 and 10 in FIG. , 30 made of soft magnetic material,
The head is configured to be large so that the heads are always facing each other even if the first or second idler is rotated to change the relative position, and the magnetic flux by the ferromagnetic body 31 forms a closed magnetic path. However, the shape of the idler holders 9'and 10 'can be simplified.

EFFECTS OF THE INVENTION As described above, according to the present invention, even when transmitting the rotational driving force from a single drive source to the reel stand via a plurality of rotation transmission systems, it is possible to achieve an ultra-thin structure with an extremely simple structure and It is possible to provide an idler device that can be downsized.

[Brief description of drawings]

FIG. 1 is a side view showing the first embodiment of the present invention, and FIG.
FIG. 3 is a partially exploded perspective view of the same main part, FIG. 3, FIG. 4 and FIG. 5 are plan views of the same main part, FIG. 6 is a side view showing a second embodiment, and FIG. And FIG. 8 is a side view showing a conventional example. 8 …… Center gear, 9 …… First idler holder, 10 ……
2nd idler holder, 11 …… 1st idler, 12 …… 2nd
Idler, 16 ... Take-up reel stand, 17 ... Supply reel stand, 18 ... First idler controller, 19 ... Second idler controller, 29 ... First idler shaft, 30 ... Second
Idler axis.

Claims (3)

[Claims] 1. A rotary drive unit including at least a ferromagnetic member, and a rotary drive unit which is constantly engaged with the rotary drive unit and abuts and separates from a reel base or a rotational force transmitting member for the reel base. Alternatively, the first and second parts forming a part of the second rotational force transmission system.
An idler, and first and second idler holders made of a soft magnetic material that axially support the first or second idler and have the same rotation center as the rotation drive unit and face each other via the rotation drive unit. , A first engaging member which engages with the first or second idler holder, and controls contact and separation of the first or second idler with the reel base or a rotational force transmitting member on the reel base. And an idler device having a second idler controller. 2. A substantially closed magnetic circuit of magnetic flux from the ferromagnetic body portion is formed by the ferromagnetic body portion of the rotary drive portion and the soft magnetic bodies of the first and second idler holders. The idler device according to claim 1. 3. A first idler and a second idler, respectively.
First and second soft magnetic materials that are axially supported by the idler holder
The first idler shaft and the second idler shaft have an idler axis, and a substantially closed magnetic path of magnetic flux from the ferromagnetic portion of the rotation drive section is formed.
The idler device according to claim 1, wherein the idler shafts are formed so as to closely face each other.