JPS6240773B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for stably and reliably driving a magnetic tape in a magnetic tape cassette.

Hereinafter, the present invention will be explained based on illustrated embodiments. In the drawing, a reel 12 for winding a magnetic tape 10 is rotatably housed in a cassette shell 14 constituting a magnetic tape cassette. It is guided by a guide post 18 provided in the cassette shell 14 so as to cross a notch 16 provided in the cassette shell 14 .

When the cassette shell 14 is attached to a magnetic recording/reproducing apparatus, the capstan shaft 20 is located on the back side of the magnetic tape 10 in the notch 16, as shown in the figure. At a location facing the capstan shaft 20 across the magnetic tape 10, a pinch roller 22 is rotatably held by a shaft 24 for press-contacting the capstan shaft 20 to transfer the magnetic tape 10 when necessary. There is. The shaft 24 is implanted at one end of a pinch roller arm 28 rotatably held by a rotation shaft 26, and
2 has a structure that allows it to move toward and away from the capstan shaft 20 around the rotation shaft 26.

On the other hand, a guide shaft 30 is located downstream of the capstan shaft 20 with respect to the running direction of the magnetic tapes 10, 10' and on the back side of the magnetic tape 10 within the notch 16. This guide shaft 30 is implanted at the tip of a guide arm 34 which is rotatably held by a rotation shaft 32, so that the guide shaft 30 moves around the rotation shaft 32. It's summery. A pinch pin 36 is implanted in a part of the guide arm 34, and a cam 38 fixed to the pinch roller arm 28 is installed near the pinch pin 36.
is located. This cam 38 is rotated by the rotation of the pinch roller arm 28 to rotate the pinch pin 3.
6 and serves to rotate the guide arm 34.

Next, the operation and effects of this embodiment will be explained. For example, in a recording or reproducing mode in which the magnetic tape 10 housed in the cassette shell 14 is held between the capstan shaft 20 and the pinch roller 22 and is transported from left to right in the figure,
The magnetic tape 10 is pulled out from the cassette shell 14 and brought to a position 10' indicated by a chain line. That is, the pinch roller arm 28 is driven by a drive means (not shown) to rotate the rotation shaft 2.
The pinch roller 22 is rotated counterclockwise about 6 and brought to the position shown at 28'.
is pressed onto the capstan shaft 20 via the magnetic tape 10 as shown at 22'. On the other hand, as the pinch roller arm 28 rotates counterclockwise, the cam 38 kicks the pinch pin 36 installed in the guide arm 34 to the right, so that the guide arm 34 moves as shown by 34'. Rotation axis 32
Rotate clockwise around the center. As a result, the guide shaft 30 provided on the guide arm 34 is 30'
The magnetic tape 10 is moved outward from the notch 16 as shown by , and the magnetic tape 10 is pulled out from inside the cassette shell 14 as shown by 10', and the magnetic tape 10 is moved to the outside of the pinch roller at the position shown by 22'. The wrapping angle is increased to stabilize the transfer of the magnetic tape 10' in the direction of the arrow. Here, the respective movement trajectories of the guide shaft 30 and the pinch roller 22 are in a relationship such that they partially interfere with each other, and the pinch roller 22 moves slightly counterclockwise from the state where the pinch roller 22 is located away from the capstan shaft 20. In the rotated position, it is extremely important that the guide shaft 30 be moved from the inside to the outside of the notch 16, that is, rotated clockwise, to a position where it does not interfere with the pinch roller shown at 22'. be.

In this structure, since the guide shaft 30 is moved by a cam 38 provided on the pinch roller arm 28 that moves the pinch roller 22, the rotational relationship between the pinch roller 22 and the guide shaft 30 is is always kept constant at a timing determined by the shape of the cam 38, and the pinch roller 22 and guide shaft 30 do not interfere. In the drawings, the magnetic tape 10' indicated by the chain line comes from the upper right diagonally because this embodiment is applied to a video tape recorder. This is because they are getting used to it.

As described above, in the magnetic tape drive device of the present invention, the movement relationship between the guide shaft and the pinch roller for pulling out the magnetic tape and increasing the wrapping angle around the pinch roller is always kept constant, so the operation is reliable. It has a simple structure and requires no adjustment, and is extremely effective in running and driving the magnetic tape stably and reliably.

[Brief explanation of the drawing]

The drawing is a plan view of essential parts of a magnetic tape drive device according to an embodiment of the present invention. 10... Magnetic tape, 14... Cassette shell, 16... Notch, 20... Capstan shaft, 22... Pinch roller, 28... Pinch roller arm, 30... Guide shaft, 34... Guide arm, 36...Kitsukupin, 38...Cam.

Claims (1)

[Scope of Claims] 1. When a magnetic tape cassette having a notch and configured to guide a part of the magnetic tape across the notch is installed, the magnetic tape that is present in the notch is a capstan shaft for driving a magnetic tape located on the back side of the magnetic tape; and a capstan shaft for driving a magnetic tape, which is rotatable so as to be movable between a first position spaced from the capstan shaft and a second position where the capstan shaft is in pressure contact with the capstan shaft. a pinch roller held by a first movable lever, and in the vicinity of the capstan shaft;
and a second lever rotatable so as to be movable between a third position located on the back side of the magnetic tape in the notch and a fourth position located outside the notch. the tape pull-out member held by the tape pull-out member, and the first A magnetic tape drive device comprising: an actuation mechanism that rotationally displaces the second lever by rotation of the lever. 2. The magnetic tape drive device according to claim 1, wherein the operating mechanism is constructed using a cam mechanism.