JPS5914923Y2 - Tape tensile force measuring device using capstan and pinch roller of cassette type tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape tensile force measuring device for measuring the tape tensile force caused by a capstan and a pinch roller in a cassette tape recorder.

Note that in this text, the term "tape recorder" includes tape players, VTRs, and EVRs.

In a cassette type tape recorder such as a reel-to-reel type or a rear jet type, a spring gauge or a fan gauge has conventionally been generally used to measure the tensile force of the tape caused by a capstan and a pinch roller.

However, in order to measure the tape tensile force caused by the capstan and the pinch roller using such a device, the measurement operation is extremely complicated and inefficient, and it is difficult to perform highly accurate measurement.

The present invention was devised to correct the above-mentioned defects.According to the present invention, although the structure is relatively simple, the tape pulling force caused by the capstan and the pinch roller can be reduced. Measurement can be carried out easily and accurately, and the urging means and tape-shaped body can have excellent durability.

Next, an example of applying the present invention to a tape tensile force measuring device using a capstan and a pinch roller in a reel-to-reel type cassette tape recorder will be described with reference to the drawings.

As shown in FIG. 1, the cassette casing 2 of the tape tensile force measuring device 1 is a conventional magnetic tape recorder used in a reel-to-reel type cassette tape recorder that measures the tape tensile force generated by a capstan and a pinch roller. It may be formed in exactly the same manner as the casing of a recording/reproducing tape cassette, and each half of the casing is integrally molded from transparent synthetic resin.

Therefore, the casing 2 includes a pair of reel shaft insertion holes 3 and 4, a recording/playback head insertion window 5, a pair of pinch roller insertion windows 6,
7, a pair of capstan insertion holes 8, 9 and a pair of cassette engagement pin insertion holes 10, 11, respectively.

Inside the cassette casing 2, guide rollers 13 and 14 are rotatably disposed near both ends of the front section 12, and tape pads 13 and 14 are provided inside the head insertion window 5.
5 are arranged.

A torque measuring section 21 is disposed in the cassette casing 2 at a position corresponding to one reel shaft insertion hole 3,
In addition, at a position corresponding to the other reel shaft insertion hole 4,
A torque limiter section 68 is provided.

The torque measuring section 21 includes a synthetic resin inner ring 22 which has an engaging protrusion 23 on its inner peripheral surface that can engage with a reel shaft of a tape recorder and is rotatably supported by the cassette casing 2, and this inner ring. A synthetic resin outer ring 30 is disposed concentrically around the outer periphery of the outer ring 22.

Three screw holes 65a, 65b, and 65C are formed on the upper surface of the inner ring 22 at intervals of 120 degrees, and corresponding to these screw holes, the upper half of the cassette casing 2 has screw holes as shown in FIG. A screw insertion hole 66 is formed as shown in FIG.

Since the screws 67 inserted into these screw insertion holes 66 are screwed into the screw holes 65 a, 65 b, and 65 C of the inner ring 22, the inner ring 22 is integrally fixed to the cassette casing 2.

In this case, the inner ring 22 does not necessarily need to be fixed integrally to the cassette casing 2, and may have some play with respect to the casing as in this type of reel, which is known in the art. , the inner ring 22 must be rotatably driven by the supply reel shaft 44 and the outer ring 30 must be rotatably driven via the balance spring 16, which will be described later.

Note that if the screw 67 is removed and the inner ring 22 is rotated an appropriate number of times and then the screw 67 is reinstalled in the same state, different parts of the tape-shaped body 40 will be used for torque measurement, so only the same part of the tape will be used. There is less risk of damage to the tape than when torque measurements are repeated.

Ring-shaped grooves 31 and 32 each having a semicircular cross section are formed on the outer peripheral surface of the inner ring 22 and the inner peripheral surface of the outer ring 30, respectively.

The cross section formed between the two wheels 22 and 30 by these grooves 31 and 32 is a flat circular ring-shaped groove 2.
Inside 5, a plurality (for example, six) of metal or resin spherical bodies 33 having the same shape as the flat circular shape are centered around a retainer shaft 35 that is inserted into a center hole 34 penetrating vertically. It is fitted so that it can rotate freely.

Since the grooves 25 and the spherical body 33 are each flat circular, the spherical body 33 rolls about its center hole 34 regardless of the presence or absence of the shaft 35.

The retainer shaft 35 is made of metal or synthetic resin, and both ends thereof are connected to ring-shaped retainer plates 36 made of metal or synthetic resin.
．． 37, each is caulked.

Retainer plates 36 and 37 are provided on both sides of the groove 25 and on the inner ring 22.
and the outer ring 30, respectively, are inserted into ring-shaped recesses 38, 39 formed across the outer ring 30.

Since the width of the retainer plates 36 and 37 is larger than the width of the upper end or the lower end of the groove 25, there is no fear that the retainer plates 36 and 37 will sink into the groove 25.

Also, since the distance between the inner surfaces of the recesses 38 and 39 is equal to the distance between the retainer plates 36 and 37, the retainer plate 36
．． 37 are held in place with respect to the inner ring 22 and the outer ring 30 by contacting the inner surfaces of the recesses 38 and 39, respectively, and
Furthermore, they are rotatable within the recesses 38 and 39, respectively.

Note that in order to rotatably support the outer ring 30 with respect to the inner ring 22, a normal ball bearing may be used instead of the retainer plates 36 and 37, the spherical body 33, and the retainer shaft 35.

The balance spring 16 is disposed within the recess 39 on the outside of the retainer plate 37.

The hairspring 16 is a spiral metal wire spring, and both ends 16a and 16b of the balance spring 16 are fitted into fixing holes 17 and 18 of the inner ring 22 and the outer ring 30, respectively.

A step portion 47 is formed on the upper surface of the outer ring 30 at the outer peripheral end of the recess 38.
is formed, and a torque display scale 27 is formed on this stepped portion 47.

Corresponding to this scale 27, a metal pointer 59 extending in the radial direction is fixed to the upper surface of the inner ring 22 at its base.
The tip, which is the free end, extends to the top of the scale 27.

On the other hand, the torque limiter section 68 includes an inner ring 60 made of synthetic resin, which has an engaging protrusion 23 on its inner peripheral surface that can engage with a reel shaft of a tape recorder, and is rotatably supported by the cassette casing 2. A synthetic resin outer ring 61 is provided on the outer periphery of the inner ring 60 and concentrically arranged therewith.

A ring-shaped strip groove 62 and a mallet are formed on the outer peripheral surface of the inner ring 60 and the inner peripheral surface of the outer ring 61, respectively.

In addition, a rectangular linear spring 70 is connected to an inner ring 60 and an outer ring 61.
The inner ring 60 is surrounded by a ring-shaped space 55 formed between the inner ring 60 and the inner ring 60.

The four side portions 70a of the linear spring 70 are fitted into the ring-shaped groove 62 of the inner ring 60 in a press-fit state at their central portions.

In addition, the four ring-shaped parts 70b formed between the respective side parts 70a (i.e., the corner parts) of the linear spring 70 are connected to the ring-shaped line of the outer ring 61 at the center thereof. It is fitted into the groove 63 in a crimped state.

Also, a pair of insertion holes 56 formed in the filament groove 62.
Insertion portions 70C formed at both ends of the wire spring 70 are inserted and fixed into the respective ends of the wire spring 57.

Therefore, the linear spring 70 is integrally connected to the inner ring 60, and also presses and holds the outer ring 61 at its ring-shaped portion 70b.

A ring-shaped collar portion 60 is located near the upper end of the outer periphery of the inner ring 60.
a is formed, and a ring-shaped metal plate 58, on which a torque display scale can be attached if necessary, is fixedly adhered to the upper surface of this flange.

This metal plate 58 is not particularly necessary in this embodiment, and merely functions as a blind plate.

Therefore, in this embodiment, the inner ring 60, the outer ring 61 . The wire spring 70 and the metal plate 58 constitute a winding survey rolling body.

Both ends of a tape-shaped body, such as a normal magnetic tape 40, are fixed to the outer rings 30 and 61 by metal fixing pins 41 and 42, respectively.

This tape 40 is wound around outer rings 30 and 61, respectively, and is wound in a U-shape between these by guide rollers 13, 14, as in the case of a normal tape cassette.

Therefore, when measuring the tape tensile force caused by the capstan and pinch roller, as shown in FIG. ] and then put the tape recorder into recording or playback mode.

In this installation, as shown in FIG. 1, the supply reel shaft is fitted into the inner ring 22 of the torque measuring section 21, and the take-up reel shaft 45 is fitted into the inner ring 60 of the torque limiter section 68, so that they are mutually connected. to engage.

In this recording or reproducing state, the recording/reproducing head 54
moves forward to press the tape 40 onto the tape pad 15, and along with this, the capstan 50 and the pinch roller 51
By their cooperative action, the tape 40 attempts to run normally at a predetermined speed.

The take-up reel shaft 45 also tries to rotate in order to wind up the tape.

However, since the inner ring 22 of the torque measuring section 21 is fixed to the cassette casing 2, the tape that is pulled in the normal running direction by the cooperative action of the capstan 50 and the pinch roller 51 is It stops in a state in which the tape pulling force exerted by the pinch roller 51) and the restoring force of the hairspring 16, which is elastically deformed by this pulling force, are balanced.

That is, in this state, the outer ring 30 is rotating with respect to the inner ring 22 against the balance spring 16, so a relative displacement occurs between them, and the balance spring 16 is rotated by its winding. is elastically displaced in the direction.

Due to this displacement, the scale 27 rotates counterclockwise in FIG. 1 relative to the pointer, so that the pointer 59 indicates the scale 27 corresponding to the tape pulling force exerted by the capstan and the pinch roller.

Therefore, it is sufficient to read the scale 27 indicated by the pointer 59 on the surface of the torque measuring section 21 through the transparent casing 2.

In this tape tensile force measuring device 1, 160
Although it is possible to measure torque up to g-cm, in this type of tape recorder, the tape pulling force by the capstan and pinch roller is usually 60±20 gcm in terms of reel rotational torque.

Due to the above-described displacement, the outer ring 30 rotates relative to the inner ring 22, and this rotation is performed extremely smoothly due to the displacement of the spherical bodies 33 within the grooves 25.

In addition, due to the presence of the spherical body 33, the outer ring 3 is different from the inner ring 22.
There is no possibility that 0 will be displaced in the axial direction, that is, in the vertical direction in FIG.

Furthermore, since the spherical body 33 is pivotally supported by the retainer shaft 35 on the retainer plates 36 and 37, the spherical body 33
The relative spacing between each other is always kept constant.

In this way, if the above-described tape tensile force measuring device 1 is used, the tape tensile force exerted on the tape 40 by the capstan and the pinch roller can be measured under the same conditions as in the case of a tape of a normal reel-to-reel type tape cassette. can be measured.

In addition, when the stop button is pressed in the state where the tape tension force is measured by the capstan and the pinch roller described above, the brakes are applied to the supply reel stand and take-up reel stand of the tape recorder, so that the supply reel shaft 44 and the take-up reel stand are respectively braked. The take-up reel shafts 45 each stop while maintaining the same state.

Furthermore, the pinch roller 51 is also separated from the capstan 50.

Therefore, in this embodiment, if the torque limiter section 68 disposed on the tape winding side is a normal reel as is conventionally known, the outer ring 30 of the torque measuring section 21 is also composed of a capstan and a pinch roller. It attempts to stop at a position rotated relative to the inner ring 22 by an amount corresponding to the tape tensile force.

Also, in this state, a force equivalent to the tape pulling force from the capstan and pinch roller is applied to the balance spring 16 and tape 40. Therefore, if this stopped state continues for a long time, the spiral spring and tape will become fatigued. These may cause damage.

However, in this embodiment, such fatigue can be effectively prevented.

That is, since the pinch roller 51 separates from the capstan while the tape tension force by the capstan and the pinch roller is applied to the tape, the outer ring 61 of the torque limiter section 68 also has a torque force corresponding to this tape tension force. ru.

Therefore, if this torque is larger than the torque limited by the torque limiter section 68, for example Log-cm, the ring-shaped section 70b of the outer ring 61 and the linear spring 70
A slip occurs between the outer ring 61 and the outer ring 61 to rotate clockwise in FIG.

Therefore, since the tensile force applied to the tape decreases, the amount of winding of the balance spring 16 also decreases, and as a result, the balance between the restoring force of the balance spring and the minimum torque value limited by the torque limiter section is maintained. The whole thing stops.

Therefore, in this state, the amount of elastic displacement of the hairspring and the tape tension are relatively small, so there is no fear that the hairspring and tape will become fatigued in a short period of time.

Furthermore, due to the presence of the torque limiter section 68, when measuring the tape tensile force, even if the take-up reel shaft 45 attempts to wind the tape with a winding torque that is greater than the minimum torque value limited by the torque limiter section, This torque limiter section 68 maintains the torque below the minimum torque value.

Therefore, the winding torque caused by the take-up reel shaft 45 does not particularly adversely affect the measurement of the tape tensile force caused by the capstan and the pinch roller, and therefore more precise measurement can be performed.

If the eject button is pressed and the torque measuring device is removed from the cassette mounting position of the tape recorder, the amount of elastic displacement of the balance spring will be restored to zero.

In the above embodiment, the inner ring 22 of the torque measuring section 21 is formed separately from the cassette casing 2, but it may be formed integrally with the lower casing to form a part of the cassette casing.

Further, in the above embodiment, a rectangular linear spring 70 is used as the torque limiter, but a friction transmission mechanism consisting of a pair of friction surfaces may also be used, or a normal reel may be used instead of the torque limiter. It's okay.

As described above, according to the present invention, the tape tensile force exerted by the capstan and pinch roller of the tape recorder can be measured simply by attaching the cassette casing to a predetermined location on the cassette type tape recorder and operating the tape recorder.

Therefore, the measurement operation is extremely simple and efficient compared to the case of measuring using a spring balance or a fan gauge.

Furthermore, since the tension of the tape can be directly measured, it is possible to easily perform highly accurate measurements.

In addition, a locking protrusion for engaging the take-up side reel shaft with the take-up side reel shaft is attached to the take-up side reel shaft. The tape-like body sent from the winding reel shaft to the winding reel shaft is wound onto the winding body by the rotation of the winding reel shaft.
For this reason, there is no need to provide a biasing means such as a balance spring for winding up the tape-like body on the winding-side rotary body, and the structure is therefore relatively simple.

In addition, since the tape-like body is wound onto the take-up reel shaft by the rotation of the take-up reel shaft, the cassette casing is taken out from the cassette mounting part of the tape recorder and the tape-like body is wound onto the take-up reel shaft. When the lock is released, no load is applied to the biasing means for biasing the rotating wheel, and thus to the tape-like body, and for this reason, it is possible to obtain a biasing means and tape-like body with excellent durability. I can do it.

[Brief explanation of the drawing]

The drawing shows an example in which the present invention is applied to a tape tensile force measuring device using a capstan and a pinch roller in a reel-to-reel type cassette tape recorder. The plan view when in use in the state shown in FIG. 2 is similar to that shown in FIG.
3 is a back view of the torque measuring section shown in FIGS. 1 and 2, FIG. 4 is an exploded perspective view of the same as above, and FIG. 5 is a sectional view taken along line V-V in FIG. FIG. 6 is a back view of the torque limiter section shown in FIGS. 1 and 5. FIG. In addition, in the symbols used in the drawings, 1...
・Tape tensile force measuring device, 2...cassette casing, 16...balance spring (energizing means)
, 21...Torque measurement part, 22...Inner ring (supporting part), 23...Engaging protrusion, 30...
...Outer ring (rotating ring), 50...Capstan, 51...Pinch roller, 59...
Pointer, 60...Inner ring, 61...Outer ring,
68...Torque limiter section, 70...
It is a linear spring.

Claims (1)

[Claims for Utility Model Registration] In a cassette casing that can be installed in the cassette mounting part of a cassette type tape recorder, (a) a winding rotating body disposed at a position corresponding to the winding side reel axis of the tape recorder; , (b) a locking protrusion attached to the winding rotary body for engaging the winding rotary body with the winding side reel shaft; (C) a retaining projection attached to the winding rotary body to engage the winding rotary body with the winding side reel shaft; (d) a rotary ring disposed concentrically and rotatably relative to the support part on the outer periphery of the support part, and (e) the above-mentioned (f) a tape-like body configured to be transported by a tape tensioning force by a capstan and a pinch roller of a tape recorder and associated with said winding roller and said rotating wheel respectively; (f) by said tape tensioning force; further comprising a biasing means for biasing the rotary wheel against the support portion in a direction opposite to the direction of the rotational torque applied to the rotary wheel via the tape-shaped body, the support portion being at least substantially coupled to the cassette casing in the direction of rotation of the rotating wheel, and configured to measure a tape tensile force in response to a rotational position of the rotating wheel rotating relative to the support member against the biasing means. A tape tensile force measuring device using a capstan and a pinch roller for a cassette tape recorder.