JPH079726B2 - Tape production mechanism - Google Patents

Description

The present invention relates to a tape loading mechanism in a magnetic recording / reproducing apparatus such as a video tape recorder (VTR).

[Conventional technology]

As a conventional mechanism of this type, for example, there is one as shown in FIG. This mechanism has a loading ring 2 which is eccentrically and rotatably provided on the outer periphery of a rotary head cylinder assembly 1 around which a tape is wound at a predetermined angle, and a guide groove 3 which is fixed along the ring 2 while being spirally inclined. A cam 4 and a guide post unit 8 provided with a stopper pin 7 on a moving base 5 slidably engaged with the guide groove 3 and provided with a stopper pin 7, and a loading ring at one end. There is provided a loading spring 10 which is a tension coil spring which is locked to 2 via a pin 9 and whose other end is locked to the guide post unit 8.

In the above configuration, when the tape cassette is loaded with the unit 8 in the unloading position (loading start end position), the tape pull-out guide post 6 is inserted inside the tape of the cassette. In this state, when the loading ring 2 is rotated in the loading direction indicated by the arrow A by a loading motor (not shown), the guide post unit 8 is also pulled up by the loading spring 10 and rises along the cam 4 along with this rotation. Slide. As a result, the tape pull-out guide post 6 pulls out the tape from the cassette and winds the tape around the rotary head cylinder 1 in an inclined state.

After the guide post 6 arrives at the end of the cam 4, the loading ring 2 stops with some additional rotation.
By this additional rotation, the loading spring 10 is stretched and its tension is increased, and at the same time, the loading spring 10 is pulled by this and the pin 7 is pulled.
Is strongly contacted with the V-shaped groove 11 at the cam end and is restrained. Hereinafter, the fact that the loading member (guide post unit 8) is captured at the fixed position at the end of the tape loading is referred to as “catching”.

In this way, the tape winding angle with respect to the cylinder 1 is kept stable against the load caused by the tape tension even when the tape is running.

FIG. 2 shows the load characteristics of the loading motor at the time of tape loading described above, in which the vertical axis represents the torque of the loading motor as a loading load and the horizontal axis represents time. The loading load is slightly high at the time of starting the loading motor, takes a constant value at the subsequent steady rotation, reaches the end of the loading and rapidly increases with additional rotation, and reaches the maximum load torque at the completion of catching (loading completion). Area of the shaded area in the figure showing a sharp rise
It can be considered that S ₁ is a work amount for imparting a resistance force (that is, a catching force) to the tension when the tape is running.

However, in the past, the structure in which the tension of the loading spring 10 applied by the additional rotation of the loading motor was used to restrain the guide post unit 8 which is a loading member at the loading end position,
There was a drawback that the catching power varied. However, if the lower limit of the torque fluctuation is made to correspond to the maximum required loading load, the loading motor would be large.

[Object of the Invention]

The present invention has been made in view of the drawbacks of the above-mentioned conventional example,
It is an object of the present invention to provide a tape loading mechanism that always enables stable catching without being influenced by torque fluctuations of the loading motor.

[Structure of Invention]

The tape loading mechanism provided by the present invention comprises a tape pull-out means for moving the tape outside the rotary head cylinder to wind the tape around the rotary head cylinder, a drive means for moving the tape pull-out means, and the tape pull-out means. A restraining member pivotally supported near the tape winding operation ending position of the means and elastically biased to the side;
The tape pulling-out means includes a detecting means for detecting that the tape pulling-out means has moved to the tape winding operation end position, and a stopping means for stopping the driving means in accordance with the output of the detecting means. When the tape winding operation is completed, the tape pull-out means engages with the elastically biased restraining member and the stop means stops the drive means.

[Operation of the invention]

According to the tape loading mechanism having the above structure, when the tape pull-out means moves to the tape winding operation end position, the tape pull-out means is pivotally supported so as to be swingable and elastically biased to the side. The member is engaged with and constrained, and the drive means for moving the tape pull-out means is also stopped.

〔Example〕

3 to 6 show an embodiment of the present invention. FIG. 3 is a side view of the tape loading mechanism in a loading start state, FIG. 4 is a side view of the same in the end state, and FIG. 5 is a side view of FIG. It is an explanatory view of the operation of the main part shown by the arrow V-V.

A guide post unit 14 that is a tape pull-out unit is provided in interlocking relation with a loading ring 12 arranged so as to surround the rotary head cylinder mounting table 11 via a post 13. 15 is a loading end detection switch,
Reference numeral 16 is a leaf spring provided on the upper end of the post 13. The guide post unit 14 is attached to a post 13 standing upright on the loading ring 12 so as to be vertically slidable and tiltable.

The guide post moving base 17 is provided with guide posts 18 and 18 axially supported on both ends of the upper surface thereof, and rollers 19 and 19 which are laterally projected and axially supported. Reference numeral 20 denotes a guide groove formed on the cylindrical side surface of the cylinder mounting table 11, which is inclined upward from the loading start end (FIG. 3) to the loading end (FIG. 4). The rollers 19 and 19 are guided by the guide groove 20 and roll.

Reference numeral 21 is a cam plate fixed to the guide post base 17 on the lower surface side through columns 22. The planar shape of the cam plate is such that, as shown in FIG. The slope 24 is provided. The cam plate 21 constitutes a restraint portion that engages with a restraint member described later.

Reference numeral 25 is a catching unit as the above-mentioned restraint member, which is pivotally supported by the tape loading end portion of the cylinder mounting table 11 so as to be swingable. 26 is an arm protruding from the side of the cylinder mounting table 11, 27 is a shaft standing on the arm 26, 28 is a swing plate attached to the shaft 27, and 29 is a catching roller rotatably supported at its end. Is.

Reference numeral 30 denotes a coil spring which is attached to the swing shaft 27 to elastically bias the swing plate 28 toward the side surface of the cylinder mounting table, that is, to the side, one end of which is fixed to the arm 26 and the other end thereof is a swing plate. 28
It comes into contact with and presses the bent side plates 28a. 28b is a stopper connected to the bent side plate 28a and abuts on the side surface of the cylinder mounting table 11.

Next, the operation of this embodiment will be described.

When the loading ring 12 rotates in the loading direction when the loading motor starts, the guide post unit 14
Is guided to the guide groove 20 via the rollers 19 and 19, and is interlockedly rotated along the side surface of the cylinder mounting table 11 while obliquely rising. The guide post 18 hooks the tape and loads it around the outer circumference of the rotary head cylinder.

Guide post unit when approaching the end of loading
The slope 24 of the cam plate 21 provided on 14 is the catching unit 25.
It comes into contact with the catching roller 29, and proceeds as it is.
Therefore, the catching roller 29 is pressed outward by the slope 24 as shown by the arrow B in FIG. This pressing force overcomes the elastic biasing force of the coil spring 30, and the catching unit 25
The rocking plate 28 of is pushed outward and opened.

The advancing force of the cam plate 21 (that is, the torque of the loading motor) acts as a wedge effect on the slope 24, and the swing plate 28 easily opens. At the loading completion position, the cam plate 21
The catching roller 29 is engaged with the concave portion 23 of this to perform catching. At the same time, the loading end is detected by the switch 15, and the loading motor is stopped. FIG. 6 shows the transition of the loading load, and the load fluctuation up to the catching start point is the same as the conventional example.

When the cam plate 21 comes into contact with the catching roller 29 and starts to push open the swing plate 28, the spring load of the coil spring 30 increases the motor load, and the coil spring 30 accumulates the winding energy. The catching roller 29 reaches the corner of the cam plate recess 23 and the load becomes maximum. Then the roller 29 is recessed 23
The coil spring 30 is unwound when the spring is engaged with and the motor load is reduced because the stored energy is released. When the catching is completed, the cam plate 21 is accurately restrained at a predetermined position by the catching roller 29 fitted in the recess 23, so that the catching can be performed with high accuracy and stability even if the spring force of the coil spring 30 is relatively small. realizable.

Now, when the workload required for loading of this embodiment is made equal to that of the conventional example of FIG. 2, that is, the shaded area S ₁
= S ₂ , since the required output of the loading motor is determined by the maximum load, a motor with a small torque is sufficient according to the present embodiment, which contributes to downsizing of the device and cost reduction.

〔The invention's effect〕

As described above, according to the present invention, when the tape pulling-out means is moved to the tape winding operation end position, the tape pulling-out means is swingably supported and elastically biased to the side. And is restrained by engaging the restraint member
Since the driving means for moving the tape pulling means is also stopped, the catching force is not affected by the torque fluctuation of the driving means as in the conventional case, and stable catching is always possible.

Further, unlike the conventional case, since the driving means is not driven (additional driving) even though the tape pull-out means is constrained, an unnecessary load is applied to the driving means and the addition of the driving means. No undesired drag force is exerted on the restraint member by driving. Therefore, the performance of the drive means and the catching performance of the restraining member can be always kept stable.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a conventional tape loading mechanism,
FIG. 2 is a loading load characteristic diagram of the one shown in FIG. 1, FIGS. 3 to 6 show one embodiment of the present invention, FIG. 3 is a side view of the main portion at the loading start end portion, and FIG. FIG. 4 is a side view of the main part of the terminal portion, and FIG.
FIG. 6 is a loading load characteristic diagram, and FIG. 1 …… Rotating head cylinder 11 …… Cylinder mounting table 14 …… Tape pull-out means (guide post unit) 20 …… Guide groove 21 …… Restricted member (cam plate) 25 …… Restriction member (catching unit)

Claims (1)

[Claims] Claim: What is claimed is: 1. A tape drawing means for moving a tape on a rotary head cylinder to move the tape outside the rotary head cylinder, a driving means for moving the tape drawing means, and a tape winding means for the tape drawing means. A restraint member pivotally supported near the operation end position and elastically biased to the side; detection means for detecting that the tape pull-out means has moved to the tape winding operation end position; Stop means for stopping the drive means according to the output of the detection means, and when the tape pull-out means moves to the tape winding operation end position, the tape pull-out means is elastically biased. A tape loading mechanism, characterized in that the stopping means stops the driving means while engaging with the restraint member.