JPH04335245A - Tape loading mechanism - Google Patents

Abstract

PURPOSE:To eliminate a load on a mode changeover cam due to press fitting of a tape drawing member to a catcher and to diminish variations of the above press fitting force. CONSTITUTION:The mechanism is composed of the mode changeover cam 1, a 1st link 7 to be turned by this cam 1 and a 2nd link 10 connected turnably with its base end to this 1st link 7 and turnably with its tip to the tape drawing member 12, and the tape drawing member 12 is moved along a prescribed course to be press-fitted to the catcher 14 by rotating the cam 1. In this tape loading mechanism, a stopper 21 for restraining the link 7 from rotating is provided in a position beyond a max. extension line of one pair of links 7 and 10, and the cam 1 is provided with a protrusion part 1c for pressing the link 7 against the stopper 21.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape loading mechanism for winding a tape around a cylinder in a magnetic recording/reproducing apparatus such as a video tape recorder (hereinafter referred to as VTR).

0002

2. Description of the Related Art FIG. 4 shows the structure of an example of a conventional tape loading mechanism provided in a VTR. In Figure 4,
A cam groove 1a is formed in a mode switching cam 1 rotatably provided on a substrate. The cam groove 1a has a support shaft 2 on the board.
A pin 4 at one end of a drive lever 3 rotatably supported via the lever is engaged. Further, a sector gear 3a is formed at the other end of the drive lever 3.

A first driving gear 5a and a second driving gear 5b that mesh with each other are rotatably mounted on the substrate, and a notched gear 6 is concentrically attached to the first driving gear 5a.
is fixed. and notched gear 6 and drive lever 3
A sector gear 3a formed at the tip of the gear meshes with the fan gear 3a. One end of a first link 7a, 7b is coaxially rotatably attached to the first and second drive gears 5a, 5b, respectively. are the first and second torsion springs 8a, respectively.
8b is included. The rotation of the first and second drive gears 5a and 5b is transmitted to the first links 7a and 7b via the first and second torsion springs 8a and 8b, respectively.

Second links 10a, 10b are connected to the other ends of the first links 7a, 7b via pins 9a, 9b, respectively.
One end of the link 1 is rotatably connected to the second link 1.
Pins 11a and 1 are attached to the other ends of 0a and 10b, respectively.
Tape drawer members 12a and 12b are rotatably connected via 1b. Tape drawer member 12a
, 12b are guide grooves 13a formed on the substrate, respectively.
, 13b. Also, the guide groove 13a
, 13b are provided with catchers 14a, 1, respectively.
4b is provided.

In the tape loading mechanism configured as described above, when a cassette (not shown) is loaded into the tape drive section, the tape loading device is activated and the mode switching cam 1 is rotated. The rotational driving force of the cam 1 is transmitted to the tape drawing member 12 via the drive lever 3, the notched gear 6, the drive gear 5, and the links 7 and 10. Then, the tape pull-out member 12 moves along the guide groove 13, pulls out the tape (not shown), and comes into contact with the catcher 14. In this state, the tape is wound around a cylinder (not shown). Further, by bending the torsion spring 8 due to the overstroke of the drive lever 3, a pressing force of the tape drawing member 12 against the catcher 14 is generated.

[0006]

However, according to the conventional tape loading mechanism configured as described above, the drive lever 3 is always used when the tape pull-out member 12 is crimped onto the catcher 14 and even after crimping. A force is applied to the mode switching cam 1, which becomes a load when switching to another mode. Also, the tape drawer member 12 is attached to the catcher 14.
There was a problem in that the pressing force applied to the cam 1 was largely influenced by the dimensional error of the cam groove 1a of the cam 1.

The present invention has been made in view of the above points, and provides a tape loading mechanism that eliminates the load on the mode switching cam due to the compression of the tape pull-out member to the catcher and reduces the variation in the compression force. The purpose is to provide [Structure of the invention]

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a mode switching cam, a first link which is rotated by the cam, and a base end of which is rotated by the first link. and a second link rotatably connected to the tip of the tape pull-out member, and the tape loader is configured to move the tape pull-out member along a predetermined path and press it against the catcher by rotation of the cam. In the mechanism, a locking means for locking the rotation of the link is provided at a position beyond the maximum extension line of the pair of links, and a protrusion is provided on the cam for pressing the link against the locking means. It is characterized by

[0009]

[Operation] According to the above structure, the link is pressed by the projection provided on the mode switching cam, rotates beyond the dead center, and is locked at that position by the locking means. As a result, the pressing force of the tape drawer member against the catcher is maintained by the locking means, and the load on the mode switching cam can be eliminated. Further, since the link itself is directly positioned by the locking means, the pressing force of the tape pull-out member against the catcher can be made almost constant.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the tape loading mechanism of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, parts corresponding to those in the conventional example shown in FIG. 4 are designated by the same reference numerals, and the explanation thereof will be omitted as appropriate. Furthermore, since the links 7 and 10, the notched gear 6, the tape pull-out member 12, and the catcher 14 are provided substantially symmetrically on the left and right with respect to the cylinder (not shown), only the left side will be described.

In this embodiment, the drive lever 3 and the drive gear 5 in the conventional example shown in FIG.
is meshed with a gear 1b formed on the outer periphery of the mode switching cam 1. Further, a protrusion 1c is provided at the end of the outer peripheral gear 1b of the cam 1 on the downstream side in the rotational direction. Further, when the line connecting the rotation center 20 of the notched gear 6 and the pins 9, 11 passes the dead center position where the line is straight, a locking means is placed at a position where the outside of the first link 7 comes into contact. A certain stopper 2
1 is provided. Although not shown, a notched gear 6
A torsion spring is provided at the connecting portion between the first link 7 and the first link 7, as in the conventional example.

Next, the operation of this embodiment will be explained. The mode switching cam 1 rotates in the direction shown by arrow A, and the outer gear 1b
When the first link 7 meshes with the notched gear 6 fixed to the first link 7, the first link 7 rotates in the direction shown by arrow B. Then, the tape pull-out member 12 connected to the first link 7 via the second link 10 moves along the guide groove 13 and pulls out the tape to the catcher 1 as shown in FIG.
4. At this time, the notched gear 6 and the outer peripheral gear 1b are disengaged, and as shown in FIG. Rotate to. As a result, the position of the pin 9 that connects the first and second links 7 and 10 connects the rotation center 20 of the notched gear 6 and the pin 11 that connects the second link 10 and tape pull-out member 12. It moves outward from the straight line 22 and crosses the dead center. Then, the position is determined by the stopper 21, and at this time, the notched gear 6 and the outer peripheral gear 1b of the mode switching cam 1 are disengaged.

According to this embodiment, the tape drawer member 1
2 is pressed against the catcher 14, the notched gear 6 and the outer peripheral gear of the mode switching cam 1 are disengaged, and the pressing force of the tape pull-out member 12 against the catcher 14 is maintained by the stopper 21. Therefore, mode switching cam 1 during crimping
It is possible to eliminate the load on the body, and the crimp force remains almost constant.

The drive mechanisms for the links 7 and 10 shown in the above embodiments are merely examples, and the invention is not limited thereto. Further, although the above embodiment has been described with respect to a tape loading mechanism of a VTR, similar effects can be obtained when applied to other magnetic recording/reproducing devices.

[0016]

As explained above, according to the present invention, the pair of links that drive the tape pull-out member are locked at a position beyond the dead center by the locking means, so that the tape pull-out member When crimping the link to the catcher, the load on the mode switching cam can be eliminated, the crimping force remains almost constant, and link positioning accuracy is improved.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the configuration of essential parts of an embodiment of a tape loading mechanism of the present invention.

FIG. 2 is an explanatory diagram showing a state in which the tape pull-out member of FIG. 1 is pressed onto a catcher.

FIG. 3 is an enlarged view of the main part of FIG. 2.

FIG. 4 is an explanatory diagram showing the configuration of an example of a conventional tape loading mechanism.

[Explanation of symbols]

1 Mode switching cam 1c Protrusion 7 First link 10 Second link 12 Tape drawer member 14 Catcher 21 Stopper (locking means)

Claims (1)

[Claims] 1. A mode switching cam, a first link rotated by the cam, a base end rotatably connected to the first link, and a tape drawer member rotatably connected to the distal end. and a second link, in which the tape pulling member is moved along a predetermined path by the rotation of the cam and is pressed against the catcher, the position beyond the maximum extension line of the pair of links. A tape loading mechanism characterized in that the tape loading mechanism is provided with a locking means for locking the rotation of the link, and the cam is provided with a protrusion for pressing the link against the locking means.