JPH04212747A - Reel drive for video cassette tape recorder - Google Patents

Abstract

PURPOSE: To change driving torque for driving a reel according to its rotating direction in an idler driving mechanism for selectively driving a supply side reel disk and a take-up side reel disk to be mounted on a supply reel and a take-up reel respectively. CONSTITUTION: The device is equipped with a master rotary body 10 to be driven by a motor, two friction rolling rotary bodies 20 and 30 to be driven by friction force with both side surfaces of this master rotary body 10, a coupling means 60 for connecting one of these two friction rolling rotary bodies 20 and 30 only at the time of rotating in one way and a slave rotary body 40 directly connected with the other one, and driving torque of the slave rotary body 40 can be varied in accordance with a direction of the rotation.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video cassette tape recorder, and more particularly to an idler for selectively driving a supply reel disk and a take-up reel disk on which a supply reel and a take-up reel are respectively mounted. The present invention relates to a video cassette tape recorder reel drive device in which the transfer torque can be varied along the rotation direction of the drive mechanism.

0002

[Prior Art] Conventional video cassette tape recorder (
The reel drive section of the VTR (hereinafter abbreviated as VTR) is constructed as shown in FIG.

In FIG. 4, a tape T mounted on a reel disk is moved in a forward direction by a supply reel 1 or a take-up reel 2.
) or reversed direction
on), and the capstan shaft 5 keeps the vehicle running at a constant speed.

[0004] The supply reel 1 and the take-up reel 2
The reel discs 1' and 2' are attached to the capstan shaft 6.
It is selectively driven by a drive mechanism 3 that transmits the power of a capstan motor 5 that rotates the motor, and an idler 4 that is rotatable along the rotational direction of the drive mechanism 3 and that receives power from the drive mechanism 3. It has become so. That is, when the drive mechanism 3 is driven in the forward direction (clockwise in FIG. 4), the idler 4 takes a position where it transmits rotation to the take-up side reel disk 2' as the drive mechanism 3 rotates, This take-up side reel disk 2' is rotationally driven in the same direction (clockwise) as the drive mechanism 3, and when the drive mechanism 3 is driven in the opposite direction,
The idler 4 is positioned to transmit rotation to the supply reel disc 1' as the drive mechanism 3 rotates, and the supply reel disc 1' is also rotated in the same direction (counterclockwise) as the drive mechanism 3. Rotationally driven.

By the way, the take-up side reel disk 2' is installed near the capstan motor 5, and does not require much driving force (torque) when the tape 7 runs in the forward direction. 1'
is installed relatively far from the capstan motor 5, and a load is applied when the tape 7 runs in the reverse direction, so a large driving torque is required.

[0006] In the above-mentioned reel drive device, it is necessary to appropriately change the torque depending on the drive mode, and for this reason, the torque is generally changed by the drive mechanism 3 of the idler 4.

[0007]

An example of a drive mechanism capable of varying the torque as described above is disclosed in Japanese Utility Model Application Publication No. 1-109835.

However, the device described in this publication has a complicated structure. That is, since three felt members and four springs are provided in order to change the torque as shown in FIG. there were.

The present invention solves the problems of the conventional ones as described above, and provides a VTR reel that can change the torque using a very simple drive mechanism composed of two felt members and two springs. The purpose is to provide a driving device.

0010

[Means for Solving the Problems] In order to achieve the above-mentioned object, a reel driving device according to claim 1 of the present invention includes a main rotary body rotationally driven by a motor, and a friction contact on both sides of the main rotary body. , the first driven by the frictional force
a friction rolling rotating body, a second friction rolling rotating body, and the first friction rolling rotating body;
Directly connected to the friction rolling rotor and connected to the second friction rolling rotor through a connecting means for transmitting rotation only when the second friction rolling rotor rotates in one direction. and a driven rotating body, and the driven rotating body is configured to be rotated with a torque that is changed depending on the direction of rotation of the driven rotating body.

Further, in the reel driving device according to claim 2, in claim 1, the connecting means includes a boss having the same diameter coaxially arranged on the second friction rolling rotary body and the driven rotary body; The present invention is characterized in that it includes a clutch spring that is in close contact with the outer circumferential surface of each boss, and one end of which is fixed to either the second friction rolling rotary body or the driven rotary body.

Furthermore, in the reel driving device according to claim 3, according to claim 1 or 2, the friction force between the second friction rolling rotary body and the driven rotary body is applied by a pressure spring. It is characterized by

[0013]

[Operation] According to the present invention constructed as described above, the rotation of the first friction rolling rotor is always transmitted to the driven rotor in any direction of rotation, whereas the rotation of the first friction rolling rotor is always transmitted to the driven rotor. Since the rotation is transmitted to the driven rotating body only when rotating in one direction, the driving torque of the driven rotating body can be changed depending on the direction of rotation.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to embodiments shown in the drawings.

FIGS. 1 and 2 show an embodiment of a VTR reel drive device according to the present invention.

FIG. 1 is an exploded perspective view of the reel drive device of this embodiment, showing the main rotating body 10 and the first
The friction rolling rotary body 20, the second friction rolling rotary body 30, and the driven rotary body 40 are each constituted by a unit assembly,
The main rotating body 10, the first friction rolling rotating body 20, the second friction rolling rotating body 30, and the driven rotating body 40 are coaxially supported on one holding shaft 51 that is provided protrudingly on the base 50. It is now possible to do so.

The main rotating body 10 is formed in the shape of a disc-shaped belt pulley, and a belt 5 is provided on the outer peripheral surface of the main rotating body 10.
A belt groove 11 into which the belt 2 is fitted is formed, and a boss insertion hole 12 is formed in the center thereof.

The first friction rolling rotary body 20 is formed into a substantially disk shape, and a first friction pad is provided on the upper surface of the first friction rolling rotary body 20 that is in contact with the lower surface of the main driving rotary body 10. 21 is attached. Further, a coupling boss 22 that can be relatively rotated within the boss insertion hole 12 of the main driving rotating body 10 is protruded from the center of the first friction rolling rotating body 20 .

The second friction rolling rotary body 30 is formed into a substantially disk shape, and a second friction pad is provided on the lower surface of the second friction rolling rotary body 30 that is in contact with the upper surface of the main driving rotary body 10. 31 is attached. Further, a clutch boss 32 of a predetermined diameter is protruded from the center of the second friction rolling rotary body 30 .

[0020] On the lower surface of the driven rotary body 40, the second
A large diameter portion 41 a having the same outer diameter as the clutch boss 32 of the friction rolling rotary body 30 is inserted through the clutch boss 32 and fitted into the coupling boss 21 of the first friction rolling rotary body 20 . A central boss 41 consisting of a small diameter portion 41b is provided protrudingly, and this driven rotary body 40 rotates together with the first friction rolling rotary body 20 and rotates together with the second friction rolling rotary body 30. are connected to allow relative rotation.

Further, a clutch spring is attached to the large diameter portion 41a of the clutch boss 32 of the second friction rolling rotating body 30 and the central boss 41 of the driven rotating body 40 so as to be in close contact with their respective outer peripheral surfaces. 60 is wound. As shown in FIG. 2, one end 61 of this clutch spring 60 is fixed to the second friction rolling rotating body 30,
These second friction rolling rotary body 30 and driven rotary body 40 are
By changing the diameter of the clutch spring 60, which will be described later, the clutch springs 60 can be coupled to each other or rotated relative to each other.

Furthermore, a pressure spring 70 is interposed between the second friction rolling rotor 30 and the driven rotor 40. This pressurizing spring 70 is connected to the main rotating body 1
0 and the first friction rolling rotor 20 and the second friction rolling rotor 30 to provide a friction force corresponding to the elastic force thereof.

FIG. 2 shows an assembled state of the reel drive device shown in FIG. 1, and the operation of the reel drive device will be described in detail with reference to FIG. 3.

When the main rotating body 10 rotates due to the running of the belt 52, the first friction rolling rotating body 20 and the second friction rolling body are brought into frictional contact with both surfaces of the main rotating body 10 by friction pads 21 and 31, respectively. The rotating body 30 is driven by a frictional force approximately equivalent to the elastic force of the pressure spring 70. As a result, the driven rotor 40 is connected to the first friction rolling rotor 20 and is therefore driven by the frictional force of the first friction rolling rotor 20.

By the way, when the rotational direction of the driven rotary body 40 is the winding direction of the clutch spring 60, the diameter of the clutch spring 60 becomes smaller as shown in FIG. 3A, and at this time, the second friction rolling rotary body Since the clutch boss 32 of No. 30 and the large diameter portion 41a of the central boss 41 formed on the driven rotating body 40 are substantially connected by the clutch spring 60, they rotate together.

However, when the rotational direction of the driven rotating body 40 is opposite to the winding direction of the clutch spring 60, the diameter of the clutch spring 60 is enlarged as shown in FIG. 3B, so that the second friction rolling The rotation of the clutch boss 32 of the rotating body 30 is no longer transmitted to the large diameter portion 41a of the central boss 41 of the driven rotating body 40 by the clutch spring 60, so that both cannot rotate together, and the second
The friction rolling rotor 30 will idle.

That is, when the driven rotating body 40 rotates in one direction, only the rotational force due to the frictional force of the first friction rolling rotating body 20 is transmitted, whereas when rotating in the opposite direction, Since the rotational force that is approximately twice the sum of the frictional force of the first frictional rolling rotating body 20 and the frictional force of the second frictional rolling rotating body 30 is transmitted, the driving torque is changed according to the rotational direction. Become.

As described above, according to this embodiment, the friction force of the second friction rolling rotary body 30 is transmitted to the driven rotary body 40 by the clutch spring 60 only when rotating in one direction. Regardless of the configuration, the driving torque of the driven rotating body 40 can be reliably changed depending on the rotation direction.

Note that the present invention is not limited to the embodiments described above, and various changes can be made as necessary.

[0030]

[Effects of the Invention] As explained above, the present invention can change the driving torque depending on the direction of rotation, so it can have a simple structure, and it can reduce costs by reducing the number of parts and assembly man-hours. It has a big effect.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an embodiment of a reel drive device for a video tape recorder according to the present invention.

[Figure 2] An assembled sectional view of the reel drive device in Figure 1

[Fig. 3] Fig. 3A and 3B are perspective views of main parts, respectively, illustrating the engaged state and loosened state of the clutch spring.

[Fig. 4] Plan view of a reel drive device of a conventional video tape recorder.

[Explanation of symbols]

10 Main rotating body 20 First friction rolling rotating body 30 Second friction rolling rotating body 40 Driven rotating body 60 Clutch spring

Claims (3)

[Claims] 1. A main rotating body rotatably driven by a motor; and a main rotating body that is in frictional contact with both surfaces of the main rotating body,
A first friction rolling rotating body and a second friction rolling body driven by frictional force.
a friction rolling rotor, which is directly connected to the first friction rolling rotor and transmits rotation to the second friction rolling rotor only when the second friction rolling rotor rotates in one direction; and a driven rotary body connected through a connecting means for rotating the video cassette tape, wherein the driven rotary body is configured to be rotated with a torque that is changed depending on the direction of rotation of the driven rotary body. Recorder reel drive device. 2. The connecting means includes bosses having the same diameter that are coaxially arranged on the second friction rolling rotating body and the driven rotating body, and closely contacting outer peripheral surfaces of the respective bosses,
2. A reel drive for a video cassette tape recorder according to claim 1, further comprising a clutch spring, one end of which is fixed to either one of the second friction rolling rotor and the driven rotor. Device. 3. The video cassette tape according to claim 1, wherein the frictional force between the second friction rolling rotor and the driven rotor is applied by a pressure spring. Recorder reel drive device.