JPS5847560Y2 - Tape driving force measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring tape driving force of a cassette type tape recorder (audio recorder, video recorder, etc.).

A meter unit and a winding frame are arranged inside the cassette case,
This cassette is designed to measure the driving force generated between the capstan and the pinch roller pressed against the capstan, that is, the tension applied to the tape, in the play mode of the tape recorder, by stretching the tape connected to both sides through the opening (cassette). - A torque meter has already been proposed by the applicant.

Figure 1 is a plan view for explaining one example.
shows the entire cassette torque meter, which has the same external shape as a compact cassette and was designed to be installed in a tape recorder, but in the case shown, the upper half has been removed to show the arrangement of internal elements. and the state at the time of tape tension measurement.

The upper half and lower half that make up the cassette...
- The cover is made of a transparent lubricating material such as polystyrene, and is designed so that the inside thereof can be seen through from the surface of the upper half to read the rotation angle indication scale of the movable outer ring of the meter unit, which will be described below.

In the figure, 2B is the lower half (the upper half 2A is shown in Figure 2), 3 is the central opening on the front side of the tape path side, 4a, 4b, 5a, and 5bl/i are openings at symmetrical positions. and small windows, 6a, 6b and 7a.

7b indicates a capstan insertion hole and a positioning hole, which are exactly the same as those of a normal compact, and the tape path is stretched with a tape T made of polyester or the like that is not coated with a magnetic layer, and the illustrated cassette The torque meter 1 is constructed by reusing the upper and lower halves of a compact cassette, combining them, and storing the following elements inside.

That is, a meter unit 8 having a spring-balanced structure using a spiral spring is disposed on the unwinding side of the cassette, and a winding frame 9 is disposed on the winding side.

The meter unit 8 includes a movable outer ring 10 and a hub 11,
This hub 11 is fixed to the cassette side by, for example, pins 12 inserted at two symmetrical positions, and an outer ring 1 surrounding the hub 11
A large number of steel balls 13 are interposed in this gap across a gap from the inner hole 0, and the entire meter unit 8 has an outer ring 10 and a hub 11 in a form similar to a radial ball bearing. is formed as an outer ring 10, and a right-handed spiral spring (not shown) is arranged on the back side of both of the outer rings, with one end (outer end) fixed to the outer ring 10 and the other end fixed to the bub 11, respectively. The spring balance is such that it is possible to detect the counterclockwise torque applied to 10 and the retape tension.

14 is a main scale displayed on the surface near the outer circumference of the outer ring 10 (in this example, O to 200g is displayed), and 15 is a subscale plate attached along the inside of the scale (this is, for example, a value below a certain value of the main scale) and for the above classifications), 16 indicates the pointer on the bubble 11 side.

Further, the winding frame 9 on the winding side has a structure in which a slip ring 18 (winding ring) is provided coaxially around the knob 1γ via an appropriate slip means.

The reason for slipping the take-up ring 18 is to keep the auto-shut-off mechanism of the tape recorder inactive due to the need to keep the take-up reel shaft rotating during tape tension measurements.

The tape T, which is fixed to a part of the outer ring 10 of the meter unit 8, is wound around the outer ring by the required length, and the tape T pulled out from the left peripheral surface of the tape layer is the same as a normal tape cassette. The tape passes through the tape path via the guide pin 19a on the feeding side and the guide roller 20aY, and is guided from the guide roller 20b1 on the winding side to the winding ring 18 of the winding frame 9 to be wound, and a part of the circular surface thereof. When measuring tape tension, the length of tape T that is fed out as the outer ring 100 rotates counterclockwise is wound up by a winding ring 18.

In the figure, 21 indicates a hole in the meter unit side bubble 11, 22 indicates a bubble hole in the bobbin 17 on the winding frame side, and 23 indicates a liner laid on the inner surface of the lower half.

The illustrated state is a case where the cassette torque meter 1 is attached to a tape recorder and the tape tension is to be measured. 22 respectively, and also insert the capstan! There is a capstan 2 in the hole 6b.
6 is positioned, and when a predetermined operation is performed, the pinch roller 27 is pressed against the capstan 26 via the tape T.

This pinch roller 2T is pressed against the capstan 26 by the elastic biasing force of the pinch lever 28, but changes in the driving force (tension from the tape side) generated between the capstan and the pinch roller teeth,
In addition to the strength of the spring 290 that applies a biasing force to the lever around the pivot 28' of the pinch lever 28, the rotational contact position of the pinch roller 270 and the horizontal position in the figure are also greatly affected, and a torque meter such as the one shown in the example is suitable for adjusting these. There is.

Reference numerals 30 and 31 shown in the phantom line are an erasing head and a recording/reproducing head.

Measurement of tape tension by such a cassette torque meter 1 applies counterclockwise torque to the outer ring 10 of the meter unit 8 via the tape T that is about to be transferred between the capstan 26 and the pinch roller 27. The rotational displacement of the outer ring that stops in balance with the driving force of the capstan and pinch roller is quantitatively measured, and such measurements are carried out at each stage of tape recorder design, prototyping, production lines, and after-sales service. The requirements for this are widely known to those skilled in the art.

It is therefore obvious that a cassette torque meter such as this example can provide many benefits in tape tension measurement.

A description of this type of measuring means that has been used in the past will be omitted.

By the way, if we examine the situation at the time of measurement mentioned above, for example, when measuring the tape tension of multiple tape recorders of the same model, and assuming that each element of those recorders is set under the same conditions, the indication scale of the meter unit 8 will be different for each recorder. The location of the tape T that slips between the capstan 26 and the pinch roller 270 also remains almost the same.

However, this is the case when measuring tension on a production line, etc., and once the tape recorder is used by a user and reaches the point of requesting after-sales service, it is inevitable that the recorder will change over time. Due to changes in the coefficient of friction between the circumferential surface and the tape (including dirt on the pinch roller), even if the contact pressure between the capstan 26 and the pinch roller 27 is within the initial setting range, the meter unit 8 may This tends to cause the inconvenience of not showing an appropriate value.

The main reason for this is that under tape tension measurement as shown in the figure, only the capstan 26 rotates, and the tape T and pinch roller 27 that are in contact with the circular surface are both in a slip state (static measurement). The only way to eliminate the above-mentioned disadvantages is to carry out dynamic measurements while transporting the tape T at a certain speed.

The purpose of this invention is to measure such dynamic tape tension,
In other words, we are trying to propose a new device that can easily and rationally measure tape driving force, but the entire device consists of a cassette torque meter and an attachment for driving the bubble of the meter unit at low speed. .

First, the outline of the tape driving force measuring device according to the present invention is as follows. ．． 8cm/S, the tape feeding speed from meter unit 8 is constant at 2.0CrrL/
This was done in order to dynamically measure the tension based on the speed difference.

That is, the above-mentioned attachment and cassette torque meter 1
The bub 11 of the meter unit 8 is driven at a constant speed in the feeding direction irrespective of fluctuations in tape tension.

Therefore, the attachment is essentially a drive device that is compatible with the cassette torque meter 1, and its specific mechanism will become clear from time to time.

In this case, since the bubble 11 of the meter unit 8 is disposed in a free state, the above-mentioned fixing pin 12 is naturally removed, and the relative rotation that occurs between the outer ring 10 and the bubble 11 is corrected. The difference in movement angle is indicated on a scale.

Fig. 2 is a perspective view for explaining the correspondence between the cassette torque meter 1 and the attachment (drive device) for measuring tape tension. For example, this has a planar contour that is slightly larger than the size of the cassette torque meter 1, and holding legs 34a, 34b, 34c, and 34d, each having an orthogonal cross section, are protruded from the four corners of its lower surface. The inner surface of the lower end of the holding leg and each corner of the cassette/torquemeter 1 are brought into contact with each other to maintain a predetermined state of correspondence, and in this state, the top surface of the cassette/torquemeter 1 is visually observed from diagonally above. It is now possible to do so.

That is, the lower surface of the gear box 33 is set so as to be separated from the upper surface of the torque meter 1 by the dimension formed by the upper surface of the torque meter 1, so that the scale of the meter unit 8 mentioned above (see FIG. 1) can be seen through from the upper surface -72A.

Then, from the lower surface of the gear box 33, of the reel shaft insertion holes 1a and 1b of the cassette torque meter 1, the drive shaft 35 corresponding to the insertion hole 1a on the feeding side is projected,
This drive shaft 35 is configured to drive the bubble 11 of the meter unit 8 or the feed-out reel shaft 24 (see FIG. 1).

The reference numbers for each part of the torque meter 1 correspond to those in FIG.

3 and 4 are a cross-sectional view and a vertical cross-sectional view of the main parts of the attachment 33, respectively, for explaining the attachment 33.

In the figure, 36 is a gear box 330 cover, 37//
i board, 38 is a DC motor disposed in the gear box, 39 is a motor shaft, 40 is a worm fixed to the free end thereof, 41 is a worm gear that meshes with this, 42 is fixed to the worm gear and is connected to the motor. A first conduction shaft supported perpendicularly to the axis 39 is shown, and this first conduction shaft 4
A driving side bevel gear 43 is provided at the extended end of the drive side bevel gear 43, and a driven side bevel gear 44 meshing with this at right angles is connected to a second transmission shaft 45.
is fixed at one end.

The second transmission shaft 45 is extended along the axis of the motor, and a worm 46 is fixed to a part of the second transmission shaft 45, and a worm gear 47 meshing with the worm 46 rotates the drive shaft 35 counterclockwise. It has become.

An exemplary conduction system is, for example, an FG-controlled motor 38.
1. This is because the rotation is transmitted to the drive shaft 35 via two sets of worm reduction mechanisms. Deviations in rotational speed due to load fluctuations on the drive shaft 35 can be almost completely prevented.

This can be easily understood from the fact that the worm mechanism's dog reduction ratio and conductivity only in the forward direction are used, and the mechanism is set in two stages.

Na', 48a. 48b, 48c and 48d are each transmission shaft 4
2. 45 is a bearing plate, 49 is a bearing of the drive shaft 35.

As is already clear, the present invention combines, for example, the attachment 32 and the cassette torque meter 1 into the embodiment shown in FIG. 2, thereby measuring dynamic tape tension (tape driving force). The tip end of the drive shaft 35 is provided with an adapter 50 that engages with the bubble 11 of the meter unit 8 (FIG. 1), and is adapted to insert, for example, three insertion pieces 51 of the adapter 50 into the inner peripheral position of the bubble hole 21. is being done.

FIG. 5 is an enlarged view showing the engagement state between the bubble 11 of the meter unit and the protrusion 51 of the adapter 50. As is well known, the inner surface of the bubble hole 21 has six protrusions 21', and The three engaging members formed around the reel shaft 240 engage at positions of 1200 arc minutes between the protrusions 21.

Therefore, in the case of this example, each insertion piece 51 of the adapter 50 is inserted into the remaining three locations to drive the bulb 11 counterclockwise at low speed.

However, when driving the bubble 11, the feeding reel shaft 24
Naturally, the rotation of the reel shaft 24 by the drive shaft 35 results in the same result.Therefore, in FIG. The conical recess 52' of the friction joint 52 and the head of the reel shaft 24 are arranged in a male-female manner,
A case is shown in which torque is transmitted from the drive shaft 35 to the reel shaft 24.

- Regardless of the discrepancy, tape tension measurement using the combination of attachment 32 and cassette torque meter 1 as described above is a dynamic measurement compared to the conventional static measurement.
Various inconveniences that occur in the case of static measurements as described above can be overcome.

In other words, in the case of a compact cassette type tape recorder, the tape T wound around the outer ring 10 of the meter unit 8 is fed out at a speed of 2.0 cm/S (this speed was determined experimentally), and this speed is compared with the original speed. Tape transfer speed of 4.8c
The tape tension, that is, the tape driving force is measured based on the relative relationship with rrL/S, and the reading of the tension value by the meter unit 8 of the cassette torque meter 1 is the same as before and is easy. Since it can be inferred, I think that there is no need to explain it.

However, in the case of this proposal, the scale and pointer exhibit a rotating state at the beginning of measurement.

Thus, according to the present invention, since the tape drive force of the tape recorder can be measured dynamically, the measured value is not only much more accurate than the conventional static measurement, but also allows for changes in the tape recorder over time. It is less affected by dirt on the pinch rollers, so it is possible to check the tape tension value set during design and prototyping under approximately the same conditions at each stage from the production line to after-sales service. Therefore, its practical effect is extremely large.

In addition, the attachment shown and explained in the embodiment has a clever structure that allows the drive shaft at the end of the transmission system to be driven at a constant speed regardless of load fluctuations, but this is beyond the scope of the gist. There is no problem with making various changes within the document.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an example of a cassette torque meter, illustrating the arrangement of its internal elements and the measurement of tape tension; FIG. 2 is a perspective view schematically showing the correspondence between the cassette torque meter and the attachment; Figures 3 and 4 are a cross-sectional view and a vertical cross-sectional view of the main parts showing an example of the attachment, Figure 5 is an enlarged plan view showing the engagement of the meter unit bubble and adapter, and Figure 6 is the drive. It is a figure which shows the example of the engagement structure of a shaft and a reel shaft. In the figure, 1 is a cassette torque meter, 8 is a meter unit, 9 is a winding frame, 10 is an outer ring, 11 and 17 are bubbles, 14
is the main scale, 16 is the pointer, 18 is the take-up ring, 24 is the feed reel shaft, 25 is the take-up reel shaft, 26 is the capstan, 27 is the pinch roller, 32 is the attachment, 3
3 is a gear box, 34 is a holding leg, 35 is a drive shaft, 38
is a motor, 40 and 46 are worms, 41 and 47 are worm gears, 50 is an adapter, 51 is an insertion piece, 52 is a friction joint, and T is a tape.

Claims (1)

[Scope of utility model registration request] A spring-balanced meter unit consisting of a movable outer ring with a scale displayed, a hub arranged concentrically with its inner hole and equipped with pointers corresponding to the scale, and an interior with a winding frame, and a continuous tape between the two. The tape recorder cassette torque meter is configured to be able to indicate the tension of the outer ring as the amount of rotational displacement of the outer ring, and an attachment is adapted to the cassette torque meter in a predetermined state. comprising a drive source, a deceleration mechanism and a drive shaft that are connected to the drive source and have conductivity only in the forward direction, and configured so that the hub of the meter unit is rotated at a low speed in the tape feeding direction by the drive shaft,
A tape driving force measuring device characterized in that it is designed to dynamically measure the tape tension of the tape recorder.