JPH0448457A - reel stand - Google Patents

Abstract

PURPOSE:To surely load a tape cassette to a reel base main body by making a second claw provided at the bottom of a center shaft part move a claw to be driven, a first claw engaged in the reel groove of a tape reel and the annular projecting part of a tape reel lower face contact to the upper face of the reel base main body when the first claw is lowered to the bottom of the center shaft part. CONSTITUTION:A second claw 22 to contact to the lower end part of plural claws to be driven 12 at the bottom of a center shaft part 2 and the center position of a projecting part tip 23 of it is shifted slightly in a circumferential direction to the center of a projecting part tip 24 of a first claw 21 and is made sharpened in a taper shape upward. Accordingly, a tape reel 9 does not contact to a high friction part 27 an upper face 26 of a reel base main body 1 by keeping lowering the first claw 21 to the bottom of the center shaft part 2 by the claw to be driven 12 and the first claw 21 and a second claw 22 of the reel base main body 1 are engaged in plural reel grooves 11 inevitably. Then, the annular projecting part 13 of the lower face of the tape reel 9 and the high friction part 27 of the upper face 26 of the reel base main body 1 contact. Thus, a tape cassette is loaded on the reel base main body 1 surely.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a reel stand used in a magnetic recording/reproducing device such as a video tape recorder.

BACKGROUND OF THE INVENTION In recent years, various types of magnetic recording and reproducing devices have been developed, and efforts are being made to achieve high performance and multifunctionality. among them,
It is desired to further improve operability, such as high-speed cueing and high-speed search with good responsiveness, which will make it possible to improve the efficiency of editing work. Therefore, in order to prevent excessive tension from being applied to the tape during the tape running transition period, a highly responsive and highly accurate tensile servo is required. There is a need for a mechanism that enables tension servo.

A conventional reel stand will be described below with reference to the drawings.

Fig. 4 is a side view of a conventional reel stand, Fig. 5 is a front view of a tape reel attached to the reel stand, and Fig. 6 is a sectional view showing the tape reel attached to the reel stand. be.

In FIG. 4, 1 is the reel stand main body. Reference numeral 2 denotes a central shaft portion, which is integrally formed in the center of the reel stand main body 1 in the vertical direction. Reference numeral 3 denotes a reel hook, which is fitted onto the central shaft portion 2 and is provided so as to be able to slide up and down along the central shaft portion 2. A spring 4 pushes the reel hook 3 upward along the central shaft portion 2. 5 is plural (
In this conventional example, there are three driving pawls, which are arranged at equal intervals around the outer periphery of the reel hook 3 and are provided integrally with the reel hook 3. Reference numeral 6 designates the tip of the convex portion of the drive claw 5, which is a sharp point that tapers upward. Reference numeral 7 denotes a reel cap, which is fitted into the central shaft part 2 at the upper part of the reel stand main body 1, and has a reel hook 3 that slides up and down along the central shaft part 2.
The range in which it can rise is regulated. 8 is a high friction part made of rubber or the like, and is provided on the upper surface of the reel stand main body 1.

Note that the reel stand main body 1 is rotated by a reel motor (not shown).

In FIG. 5, 9 is a tape reel in a tape cassette (not shown). 10 is the center hole of the tape reel 9. Reference numeral 11 denotes a plurality of (nine in this conventional example) reel grooves, which are formed at equal intervals around the outer periphery of the center hole 10 of the tape reel 9. Reference numeral 12 denotes a plurality of driven pawls (nine in this conventional example), which form a plurality of reel grooves 11. The number of these plurality of reel grooves 11 is an integral multiple of the number of plurality of drive claws 5 of the reel stand main body 1. Reference numeral 13 denotes an annular convex portion, which is provided on the lower surface of the tape reel 9 and comes into contact with the high friction portion 8 on the upper surface of the reel stand main body 1.

The operation of the conventional reel stand configured as described above will be described below.

When the tape cassette is attached to the reel stand main body 1, the reel stand glue cap 7 is fitted into the center hole 10 of the tape reel 9 in the tape cassette, and the plurality of drive claws 5 of the reel hook 3 are inserted into the center hole. It engages with a plurality of reel grooves 11 of part 10. At this time, in order to properly engage the plurality of driving claws 5 with the plurality of reel grooves 11, the protruding tips 6 of each of the plurality of driving claws 5 on the reel stand main body 1 are tapered upward. When the tape cassette is mounted on the reel stand main body 1, when the driven claw 12 of the tape reel 9 hits the slope of the tapered part of the convex tip 6 of the drive claw 5, the tape reel 9 is The drive pawl 5, which is pushed upward by the spring 4, slides into the reel groove 11 and engages with the reel groove 11. The annular convex portion 13 comes into contact with the high friction portion 8 on the upper surface of the reel stand main body 1, and the installation of the tape cassette onto the reel stand main body 1 is completed. When the reel stand main body 1 is rotated by the reel motor, the plurality of driving claws 5 in the plurality of reel grooves 11 push the side wall surfaces of the plurality of driven claws 12, and the torque of the reel motor is transferred from the reel stand main body 1. The signal is transmitted to the tape reel 9. The high friction portion 8 on the top surface of the reel stand main body 1 prevents play due to the clearance between the widths of the plurality of drive claws 5 with respect to the width of the plurality of reel grooves 11, and allows the tape reel 9 to be integrated with the reel stand main body 1. It is designed to allow you to turn it.

Problems to be Solved by the Invention In such a conventional reel stand, the plurality of driving claws 5 of the reel stand main body 1 are located at the center of any three of the plurality of nine reel grooves 11 of the tape reel 9. When the tape reel 9 is fitted into the central shaft portion 2 in this state, the plurality of driven claws 12 do not hit the convex tips 6 of the plurality of drive claws 5, and the plurality of drive claws 5 touch the plurality of drive claws 5. When the tape reel 9 engages with the reel groove 11 and the plurality of driven claws 12 hit the slopes of the tapered portions of the plurality of drive claws 5, the tape reel 9 is rotated in the rotational direction by the slopes of the tapered portions, as described above. The plurality of driving claws 5 can slide into the plurality of reel grooves 11 and engage with each other by rotating slightly in response to the force, but the plurality of driven claws 12 are not necessarily connected to the tapered portions of the convex tips 6 of the plurality of driving claws 5. The driven claws 1 do not necessarily hit the slope of the
2 and the plurality of driving claws 5 may coincide with each other, and may hit the tip of the tapered portion. In this case, since the tape reel 9 cannot receive the force in the rotational direction as described above from the tip 6 of the convex portion of the driving claw 5, the plurality of driven claws 1
The tips of the tapered portions of the tips 6 of the convex portions of the plurality of drive claws 5 remain in contact with the lower end surfaces of the drive claws 2.

That is, as shown in FIG. 6, while the driven claw 12 of the tape reel 9 is pushing down the driving claw 5 of the reel stand main body 1 to the root of the central shaft portion 2, the annular convex portion 13 on the lower surface of the tape reel 9 Sometimes the tape cassette hits the high friction portion 8 on the top surface of the reel stand main body 1 and the tape cassette is attached to the reel stand main body 1.

In this case, since the annular convex portion 13 on the lower surface of the tape reel 9 is in contact with the high friction portion 8 on the upper surface of the reel stand main body 1, the tape reel 9 slides on the reel stand main body 1 against the frictional force. Therefore, the tape reel 9 is given rotational force only by the frictional force of the high friction portion 8 without the drive claw 5 engaging with the reel groove 11. If you try to start the reel motor and rapidly start up the rotation of the tape reel 9 in such a state, the high friction part 8
As a result, a torque greater than that transmitted is applied to the reel stand main body 1, and slippage occurs between the reel stand main body 1 and the tape reel 9, making it impossible to perform highly responsive and highly accurate tension servo of the running tape. Also, due to this slippage, the tip 6 of the drive claw 5 was shifted to the position of the reel groove 11, and the drive claw 5 was pushed down.
When the tape is pushed upward by the spring force of the spring 4, the drive claw 5 suddenly and rapidly engages with the reel groove 11 of the tape reel 9, and the tape reel 9 begins to rotate with an impact, so that the tape is wound around the tape reel 9. The disadvantage is that the impact is transmitted to the tape, and in some cases may damage the tape. In addition, a high friction portion 8 is provided on the top surface of the reel stand main body 1.
If this is not provided, when the tape reel 9 attempts to start rotating, the drive claw 5 that has been pushed down by the driven claw 12 will not engage with the reel groove 11 and will end up on the lower end surface of the driven claw 12. There was also the problem that the tip 6 of the convex portion of the drive claw 5 continued to rotate while being in contact with each other.

The present invention solves the above problem, and when a tape cassette is mounted on a reel stand, the plurality of driven claws of the tape reel in the tape cassette are connected to the tapered ends of the convex parts of the plurality of driving claws. To provide a reel stand in which a plurality of drive claws of the reel stand can smoothly engage with a plurality of reel grooves of a tape reel even if the tape reel hits, and the torque of a reel motor can be reliably transmitted from the reel stand to the tape reel. .

Means for Solving the Problems In order to achieve the above object, the reel stand of the present invention includes a central shaft section inserted into a center hole of a tape reel that carries a plurality of driven claws, and It consists of a first and second pawl that engage with each other, and the distance between the center of the tip of the protrusion of the first pawl and the center of the tip of the convexity of the second pawl is slightly different from the spacing of the plurality of driven pawls. The first pawl is provided so as to be slidable in the axial direction of the central shaft portion, and the first pawl comes into contact with the plurality of driven pawls before the second pawl.

Effect of the present invention With the above-described configuration, when the central hole of the tape reel is fitted into the central shaft portion, the positions of the driven pawl and the first pawl are aligned, and the driven pawl aligns with the convexity of the first pawl. At the tip of the part,
When the first pawl is pushed down to the base of the central shaft, the second pawl provided at the base of the central shaft moves the driven pawl, and as a result, the first pawl engages with the reel groove of the tape reel. , the annular convex portion on the lower surface of the tape reel comes into contact with the upper surface of the reel stand main body, and the mounting of the tape cassette on the reel stand main body is completed.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings. Note that the same components as those in the conventional example are given the same numbers and detailed explanations thereof will be omitted.

1 and 2 are cross-sectional views showing how a tape reel is attached to a reel stand in an embodiment of the present invention, and FIG.
) is a sectional view taken along line CD in Figure 1(a), and Figure 2(b) is a cross-sectional view taken along line C-D in Figure 1(a).
A sectional view taken along the line CD in FIG. 3A and FIG. 3 are operation explanatory views of essential parts showing the operation of attaching the tape reel to the reel stand according to the embodiment of the present invention. 1 and 2, the difference from the conventional reel stand is that the first pawls (in this embodiment In addition to the second pawls 22, which are the lower parts of the plurality of driven pawls 12 of the tape reel 9, the second pawls 22 are placed at several locations around the base of the central shaft portion 2 on the reel stand body 1 (three in the example). In the example, it is provided at 6 locations),
The center of the convex tip 23 is the convex tip 24 of the first claw 21.
It is a point that is slightly offset in the circumferential direction with respect to the center and tapers upward. Also,
3(A) and (B), 12 is a driven pawl of the tape reel 9, 11 is a reel groove, 21 is a first pawl, 22
is a second claw, and 25 is a contact surface between the second claw 22 and the lower end of the driven claw 12. Both figures are cross-sectional views showing the state of contact between the lower end of the driven claw 12 and the tip 23 of the convex portion of the second claw 22. 3(a) and (b), 9 is a tape reel, 13 is an annular convex portion on the lower surface of the tape reel 9, 12 is a driven claw integral with the tape reel 9, 1 is a reel stand body, 27 is a high-friction portion on the upper surface 26 of the reel stand main body 1, which is in contact with the annular convex portion 13 on the lower surface of the tape reel 9. Both figures are cross-sectional views of the driven claw 12 along the center line of the tape reel.

Here, FIG. 3(A) shows the driven claw 12 of the tape reel 9.
The center positions of the first pawl 21 coincide with each other, the lower end of the driven pawl 12 hits the tip of the tapered part of the convex tip 24 of the first pawl 21, and the first pawl 21 aligns with the center position of the central shaft portion 2. It shows the positional relationship with the second claw 22 in a state where it is pushed down to the base,
FIG. 3(B) shows the positional relationship between the annular convex portion 13 on the lower surface of the tape reel 9 and the high friction portion 27 on the upper surface 26 of the reel stand main body 1 at that time. FIG. 3(C) shows a state in which the first claw 21 is just engaged with the reel groove 11, and the second claw 22 has entered the reel groove 11 other than the one in which the first claw 21 is engaged. (D) is tape reel 9 at that time.
The positional relationship between the annular convex portion 13 on the lower surface and the high friction portion 27 on the upper surface 26 of the reel stand main body 1 is shown.

The operation of the reel stand of this embodiment configured as described above will be described below.

When the tape cassette is attached to the reel stand main body 1, the first
As shown in Figures (a) and (b), the reel cap 7 of the reel stand body 1 fits into the center hole 10 of the tape reel 9 in the tape cassette, and the reel hook moves up and down along the center shaft 2. 3 engages with the reel groove 11 of the center hole 10. At this time, the second pawl 22 engages the reel grooves 1 at six locations other than those where the first pawl 21 engages.
1, the second claw 22 does not touch the lower end of the driven claw 12 but enters the six reel grooves 11, and the second claw 22 enters into the annular protrusion 13 on the lower surface of the tape reel 9. is in contact with the high friction portion 27 of the upper surface 26 of the reel stand main body 1. When the reel stand main body 1 is rotated by the reel motor, the first pawl 21 is completely engaged with the plurality of reel grooves 11, so that the first pawl 21 engages with the side wall surface of the plurality of driven pawls 12. can be accessed reliably. In addition, with respect to the play due to the clearance between the width of the first pawl 21 and the width of the reel groove 11, the friction force of the high friction portion 27 causes the tape reel 9 to slip, and Since the first pawl 21 is prevented from colliding suddenly, the torque of the reel motor is reliably transmitted from the reel stand main body 1 to the tape reel 9, and the tape reel 9 rotates integrally with the reel stand main body 1.

As shown in FIG. 2, in the reel groove 11 of the tape reel 9,
The first claws 21 do not engage, the center positions of the driven claw 12 and the first claw 21 match, and the lower end of the driven claw 12 is aligned with the tapered part of the tip 24 of the convex part of the first claw 21. Hit the tip,
When the first claw 21 is pushed down to the base of the central shaft portion 2, the 6
The lower ends of each of the driven claws 12 abut against the tips 23 of convex portions of second holes 22 provided at six locations on the reel stand main body 1.

At this time, as shown in FIG. 3(A), the center of the convex tip 23 of the second pawl 22 is slightly shifted in the circumferential direction with respect to the center of the convex tip 24 of the first pawl 21, Since the tip 23 of the convex portion is tapered upward, the lower end of the plurality of driven pawls 12 of the tape reel 9 that has been fitted into the central shaft portion 2 and descended is connected to the second pawl 22. Convex tip 23
The lower end of the driven claw 12 receives a rotational force from the tapered slope 25 of the tapered part and moves slightly in the direction of arrow X, and accordingly, the lower end of the driven claw 12 The tip 24 of the convex part of the first claw 21 that was in contact with the center part
The tip of the tapered portion also moves from the center of the lower end of the plurality of driven electric currents 12. Then, as shown in FIGS. 3(C) and 3(D), the first pawl 21 pushed upward by the spring 4 is rotated by the tape reel 9 by the slope of the tapered portion of the convex tip 24. By applying force in the direction and moving it, it slides into the reel groove 11 and engages with it, and as a result, the second pawl 22 also engages better with the reel groove 11 at six locations other than where the first pawl 21 engages. Then, the annular convex portion 13 on the lower surface of the tape reel 8 comes into contact with the high friction portion 27 on the upper surface 26 of the reel stand main body 1, completing the installation of the tape cassette onto the reel stand main body 1, and transfers the torque of the reel motor to the reel stand main body 1. It becomes possible to reliably transmit the information from the tape to the tape reel 9.

As described above, according to the reel stand of the embodiment of the present invention, the second claw 22 is provided at the root of the central shaft portion 2 and contacts the lower end portions of the plurality of driven claws 12, and the center position of the tip 23 of the convex portion thereof is is slightly shifted in the circumferential direction with respect to the center of the convex tip 24 of the first claw 21, and is tapered upward, so that the driven claw 12 is centered on the first claw 21. Shaft 2
The tape reel 9 will not come into contact with the high friction part 27 of the top surface 26 of the reel stand main body 1 while being pushed down to the base, and the first claw 21 and the second claw 22 of the reel stand main body 1 will be
is engaged with the plurality of reel grooves 11, and the annular convex portion 13 on the lower surface of the tape reel 9 and the upper surface 26 of the reel stand main body 1
The tape cassette is attached to the reel stand main body 1 by contacting the high friction portion 27 of the tape cassette.

In this way, the tape reel 9 and the reel stand main body 1 are integrated, the torque of the reel motor is reliably transmitted from the reel stand main body 1 to the tape reel 9, and the reel motor provides high response and high precision tension of the running tape. This makes servo possible.

In this embodiment, the high-friction part 27 is made of rubber, but the high-friction part 27 is limited to being provided by a member separate from the reel stand main body 1 fixed to the upper surface 26 of the reel stand main body 1. For example, the top surface 26 of the reel stand main body 1 may be machined with fine grooves or formed into a shape with small protrusions, or the annular protrusion 13 on the bottom surface of the tape reel 9 may be formed on the top surface of the reel stand main body 1. Any structure may be used as long as it increases the friction between the lower surface of the tape reel 9 and the upper surface 26 of the reel stand main body 1, such as using means for adhering to the tape reel 26.

Further, in this embodiment, the shape of the slope 25 of the second claw 22 is tapered upward in a symmetrical manner, but the slope 25 is not limited to a symmetrical shape; As long as the shape guides the driven claw 12 of the tape reel 9 fitted into the shaft portion 2, even if it is asymmetrical and tapered, or has a slope in only one direction, A similar effect can be obtained even if the shape has an arcuate convex portion.

Further, by forming the slope 25 of the tip 23 of the convex portion of the second pawl 22 from a material with a small coefficient of friction, even better operation can be obtained.

Effects of the Invention As is clear from the above embodiments, the present invention provides first and second pawls that engage with a plurality of driven pawls of a tape reel,
The distance between the center of the tip of the convex portion of the first pawl and the center of the tip of the convex portion of the second pawl is arranged to be slightly different from the spacing of the plurality of driven pawls, and the first pawl is aligned with the center axis. Since the first pawl is arranged so as to be able to slide in the axial direction of the part and come into contact with the plurality of driven pawls before the second pawl, the plurality of driven pawls can slide against the first pawl. The annular protrusion on the bottom surface of the tape reel does not come into contact with the top surface of the reel stand body while the tape reel is pressed down to the base of the central shaft, and the first pawl on the reel stand body can smoothly fit into the multiple reel grooves of the tape reel. To provide a reel stand in which the tape cassette is fitted to the reel stand main body in this engaged state and the torque of a reel motor can be surely transmitted from the reel stand to the tape reel.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views showing how a tape reel is attached to a reel stand in an embodiment of the present invention, and FIG. 3 is a main part showing the operation of attaching a tape reel to a reel stand in the same embodiment. Fig. 4 is a side view of a conventional reel stand, Fig. 5 is a front view of a tape reel attached to the reel stand, and Fig. 6 shows how the tape reel is attached to the reel stand. FIG. 2... Central shaft portion, 9... Tape reel, 1
0...Central hole portion, 12...Plural driven claws,
21...First nail, 22...Second nail,
23... Tip of the convex part of the second claw, 24... Tip of the convex part of the first claw. Agent's name Patent attorney Shigetaka Awano Haka 1 figure center - Marshal, c-1inr reel script failure - 71 reel number half alpha! 1L Kanriki Yamo to Mehachi (B) (D)

Claims (1)

[Scope of Claims] A central shaft portion inserted into a central hole of a tape reel having a plurality of driven pawls arranged at equal intervals, and first and second pawls that engage with the plurality of driven pawls. The distance between the center of the tip of the convex portion of the first pawl and the center of the tip of the convex portion of the second pawl is slightly different from the spacing of the plurality of driven pawls, and claws are arranged, the first claw is provided so as to be slidable in the axial direction of the central shaft portion, and the first claw comes into contact with the plurality of driven claws before the second claw. Reel stand placed on.